Secondary Logo

Journal Logo

Pulmonary disease in HIV-infected adults in the era of antiretroviral therapy

Fitzpatrick, Meghan, E.a; Kunisaki, Ken, M.b,c; Morris, Alisona,d

doi: 10.1097/QAD.0000000000001712
EDITORIAL REVIEW
Free

HIV in the antiretroviral therapy era is characterized by multimorbidity and the frequent occurrence of HIV-associated non-AIDS chronic health conditions. Respiratory symptoms and chronic pulmonary diseases, including chronic obstructive pulmonary disease, asthma, and cardiopulmonary dysfunction, are among the conditions that may present in persons living with HIV. Tobacco smoking, which is disproportionately high among persons living HIV, strongly contributes to the risk of pulmonary disease. Additionally, features associated with and at times unique to HIV, including persistent inflammation, immune cell activation, oxidative stress, and dysbiosis, may also contribute. This review summarizes the available literature regarding epidemiology of and risk factors for respiratory symptoms and chronic pulmonary disease in the current era.

aDepartment of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania

bDepartment of Medicine, Minneapolis VA Healthcare System

cDepartment of Medicine, University of Minnesota, Minneapolis, Minnesota

dDepartment of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

Correspondence to Meghan E. Fitzpatrick, Department of Medicine, University of Pittsburgh, 3459 Fifth Avenue, 628 NW, Pittsburgh, PA 15213, USA. E-mail: fitzpatrickme2@upmc.edu

Received 2 August, 2017

Revised 14 November, 2017

Accepted 16 November, 2017

Back to Top | Article Outline

Introduction

HIV-infected persons with sustained viremic control in the United States and similar high-income areas are now projected to live a close-to-normal lifespan [1,2]. This welcome shift in epidemiology has introduced new challenges into the clinical care of individuals living with HIV, as longevity has been accompanied by a higher burden of chronic diseases and comorbidities, or ‘multimorbidity’ [3]. Many of these comorbid diseases are not direct results of HIV infection or immunosuppression (and are thus termed HIV-associated non-AIDS, or ‘HANA’, conditions); nonetheless, they are independently associated with HIV infection and may present earlier, more frequently, or more severely in persons with HIV infection than in those without.

Chronic pulmonary disease and respiratory symptoms occur at high-frequency among HIV-infected individuals, and clinically relevant pulmonary conditions are commonly noninfectious. Noninfectious pulmonary conditions, including chronic obstructive pulmonary disease (COPD), gas exchange abnormalities (i.e. diffusing capacity impairment), asthma, and cardiopulmonary dysfunction are prevalent among persons with HIV, and HIV infection is associated with many of these disorders and is an independent risk factor for COPD [4,5]. Like other HANA conditions, features unique to HIV may contribute to chronic pulmonary disease in HIV. Such mediators include chronic inflammation and aberrant immune activation and regulation, endothelial dysfunction, oxidative stress, and pulmonary and systemic dysbiosis, among others. Further complicating the assessment, HIV-infected populations are enriched for confounders of the relationship between infection and lung health, including chronic and recurrent infection, injection and inhalational drug use, and – most importantly – alarmingly high rates of tobacco smoking. Unraveling the contributions of each of these contributors is a focus of current research in HIV-associated comorbidities.

Of additional concern, conditions such as COPD, diffusing capacity impairment, and cardiopulmonary dysfunction are not only becoming more frequent as the HIV-infected population ages, but they are also progressive. The incident health burden in this population will therefore likely worsen over the coming decades. Furthermore, progression may be more pronounced or more rapid in persons with HIV, particularly as the contributors to disease development and progression are incompletely understood, and no therapies have been tested specifically in HIV-infected individuals.

In this article, focused primarily on antiretroviral therapy (ART) era data, we will briefly review infectious lung disease in association with HIV, describe respiratory symptoms encountered in persons with HIV, and review the literature related to the most common noninfectious chronic lung diseases in HIV. We will discuss risk factors and pathogenesis of disease, outline available data describing differences in disease characteristics between HIV-infected and HIV-uninfected groups, and describe gaps in the literature and opportunities for further investigation to help better prevent and manage chronic lung disease in this unique population.

Back to Top | Article Outline

Infectious pulmonary complications in the current era

Although infectious complications of HIV, including pneumonia, are generally less common than they were in the pre-ART era [6,7], pulmonary infection still contributes significantly to health burden among individuals with HIV [8]. In fact, pulmonary infection remains the leading reason for hospitalization [9]. Continued pneumonia risk may be in part due to incomplete penetrance of ART coverage even in high-access regions. Up to 14% of HIV-infected persons in the United States are not aware of their infection, and a surprisingly low-percentage (30%) achieve viral suppression [10]. Even in well treated individuals, pulmonary immunity is not completely normal, potentially predisposing to an increased risk of pneumonia despite CD4+ cell count reconstitution [11]. Thus, pulmonary infection continues to threaten at-risk individuals.

Bacterial pneumonia with typical infectious organisms (Streptococcus pneumoniae, Haemophilus, Pseudomonas, Staph species, and Klebsiella) is the most frequent cause of lower respiratory tract infection in patients with HIV [8,12]. Risk factors, as expected, include low CD4+ cell count, absence of ART, and tobacco smoking, as well as injection drug use and chronic infectious hepatitis [8]. Seasonal influenza has not been proven to be more frequent among persons with HIV, but disease may be more severe, particularly in those with CD4+ cell counts less than 200 cells/μl and those not taking ART [13–15]. Importantly, influenza vaccination rates among persons with HIV remain suboptimal, at 26–57% in recent cohort studies [16,17].

Less-typical infections, which are in large part dependent on deficiencies in cell-mediated immunity, continue to occur in patients with HIV, particularly in those with a new diagnosis of AIDS or those who lack optimal viral control. Tuberculosis is declining among persons with HIV on ART therapy [18,19], as ART is associated with decrease in incidence of tuberculosis (TB) across populations and at all levels of CD4+ cell count [20]. Pneumocystis pneumonia (PCP) remains a leading cause of opportunistic infection, though the incidence has significantly decreased following the advent of ART [6]. Risk factors include CD4+ cell counts less than 200 cells/μl, lack of PCP prophylaxis, homelessness, and history of other AIDS-defining illness [21,22]. Crypotoccus and the endemic mycoses (Histoplasma, Coccidiodes, and Blastomyces) may all cause pneumonia in persons with HIV. Cryptococcosis was a frequent fungal pathogen in the pre-ART era, but incidence has decreased dramatically in the ART era [21,23]. Although primary pulmonary disease occurs, it is now rare [23]. Regarding the endemic mycoses, lower CD4+ cell count is associated with coccidioidomycosis, and pulmonary disease severity is worse with lower CD4+ cell counts, higher HIV viral load, and absence of ART [24]. Histoplasma infection is associated with detectable viremia, suggesting significant risk in association with poor viral control and immune function [25,26]. There are no data available regarding epidemiology of Blastomyces, but blastomycosis should be considered as a potential fungal pathogens in persons who have visited endemic regions.

Back to Top | Article Outline

Respiratory symptoms and functional capacity

Respiratory symptoms are common among HIV-infected persons when assessed in research settings. Although few studies have specifically included validated assessment tools targeting patient experience of respiratory health [e.g. the St. George's Respiratory Questionnaire (SGRQ)], several investigators have included basic questionnaire data regarding patient self-report of symptoms. These symptoms, including cough and phlegm production, breathlessness, or wheeze have been found in greater than 30% of participants in HIV cohort studies [27–31]. Comparisons of symptoms between persons with HIV and those without have varied by setting and cohort [28,32]. A large study sampling 3872 participants from the US multicenter MACS (Multicenter AIDS Cohort Study) and WIHS (Women's Interagency HIV Study) cohorts found HIV to be an independent risk factor for cough, dyspnea, and wheeze among men in the MACS and for wheeze among women in WIHS [28]. A recent Cochrane meta-analysis and systematic review also found that people living with HIV are more likely than those without to experience respiratory symptoms. Cough was only significantly more common in association with HIV in populations without access to ART in the pooled estimates (possibly representing infectious causes), but breathlessness was more common in HIV-infected persons despite ART [33].

Chronic respiratory symptoms are not typically isolated findings. In the general population, respiratory symptoms have been associated both with poorer health-related quality of life and with underlying lung disease [34]. In persons with HIV, symptoms may similarly be attributable to chronic lung disease and have been associated with abnormal pulmonary function testing, including worse airway obstruction and decreased diffusing capacity [28,30,32,35] as well as elevated pulmonary artery pressures on echocardiogram [36]. In addition, respiratory symptoms and functional impairment are related, likely via linkage with underlying pulmonary disease. A commonly used and validated measure of functional capacity and physical endurance is the 6-min walk distance [37]. A study of US veterans with HIV found chronic cough to be independently associated with worse performance on 6-min walk testing, mediated by worse airflow limitation on pulmonary function testing [29]. Data from the same cohort found that chronic cough or phlegm and reduced 6-min walk distance were associated with radiographic emphysema among persons with HIV, but not in those who were not HIV-infected [38]. This differential symptom association in persons with early pulmonary disease has raised questions as to whether systemic and local inflammation in HIV lung disease is a unique contributor to respiratory symptoms and functional impairment.

There may also be associations of respiratory symptoms with quality of life and underlying pulmonary disease that are unique to HIV. A recent cross-sectional study of respiratory health status comparing SGRQ scores in HIV-infected ART-treated adults versus uninfected persons found that HIV infection was independently associated with worse respiratory health status [39]. Among persons with HIV, worse airflow obstruction, current smoking, and higher serum levels of the inflammatory marker IL-6 have been associated with worse SGRQ scores [40].

Pulmonary function testing is indicated as part of the initial evaluation for lung disease in persons with chronic respiratory symptoms and for monitoring of lung function in known lung disease. Of concern, despite the high prevalence of reported respiratory symptoms and participant experience of poor respiratory health status, diagnostic pulmonary testing of symptomatic individuals is infrequently performed in HIV clinics [28]. One study specifically identifying HIV-infected persons at increased risk for obstructive lung disease found that of those identified as high-risk (83% of whom were classified as such based on chronic respiratory symptoms, prior hospitalization for respiratory indication, or reported history of chronic lung disease), 90% had never had spirometry [41]. These findings suggest either that respiratory signs and symptoms are not ascertained in clinical care outside of the research setting, or that appropriate diagnostic testing is not readily pursued. Under-recognition of symptoms and disease in clinical practice may lead to missed opportunities for risk reduction and treatment among persons with HIV.

Back to Top | Article Outline

Noninfectious pulmonary complications of HIV

Although the risk of acute pulmonary infections has decreased in the modern ART era, noninfectious pulmonary complications have taken on increased importance. HIV infection is an independent risk factor for several clinically important respiratory syndromes and diseases, including COPD, diffusing capacity impairment (a decrease in respiratory gas exchange), asthma, and pulmonary hypertension. These conditions are associated with increase in respiratory symptoms, decreased health-associated quality of life, increased healthcare costs, and increased mortality. Of note, primary lung cancer, which is beyond the scope of this review, is also more common among people living with HIV than uninfected persons, and is the leading cause of cancer-related death. HIV-associated lung cancer has been reviewed in detail elsewhere [42,43].

The degree to which these conditions are driven by specific HIV-related factors versus shared confounding risk factors remains unclear, but broad unifying syndromes inherent to acute and chronic HIV infection have been proposed as pathophysiologic mechanisms leading to pulmonary disease and symptoms. These include microbial translocation and resultant inflammation, chronic inflammation engendered by lymphocyte activation, macrophage/monocyte activation, endothelial dysfunction, oxidative stress, and changes to the host microbiome (Fig. 1). Translational investigations assessing contributions of each of these inter-related processes to pulmonary disease and dysfunction will be reviewed.

Fig. 1

Fig. 1

Back to Top | Article Outline

Chronic obstructive pulmonary disease and emphysema

COPD is a disease characterized by persistent airflow limitation and is classically described as resulting from two phenotypes or patterns of disorder: chronic bronchitis and emphysema. Chronic bronchitis is characterized by airway inflammation and mucus hypersecretion, clinically manifest by chronic cough and sputum production. Emphysema describes the loss of surface area and gas exchange capacity of lung alveoli; the destruction of lung tissue also contributes to physiologic abnormalities including decrease in lung elastic recoil with subsequent ‘air trapping’ or dynamic hyperinflation. Both phenotypes of COPD are associated with breathlessness, decreased functional capacity, and decreased quality of life. COPD is diagnosed in the clinical setting by demonstrating airflow obstruction on spirometry. Emphysema also leads to gas diffusing impairment on pulmonary function testing and may be recognized radiographically on chest imaging studies, including quantitative and qualitative interpretations of computed tomography (CT) scans. COPD is typically a smoking-related disease, but among persons with HIV, as in the general population [44], pulmonary function abnormalities and emphysema are also detected in nonsmokers, suggesting additional mechanisms of pathophysiology that are independent of smoke exposure.

COPD is one of the better characterized HIV-associated chronic lung diseases, with a long history in the epidemic. The first formal report of HIV-associated COPD in 1989 described premature bullous disease and emphysema in 42% of CT scans of persons with AIDS in a retrospective chart review [45]. A study published in 2000, including both pre and post-ART participants, documented an increased frequency of radiographic emphysema in young persons infected with HIV (15%), including those who did not smoke tobacco, compared with matched controls (2%) [46]. Subsequent descriptive cohort studies have generally reported high-proportion and rate of COPD, either from administrative data or self-report [4,5] or as measured by spirometry [27,30,47–55], with prevalence reports of 3–27% for airflow obstruction and 10–37% for radiographic emphysema [46,52,56–58], depending on the classification methods used (Table 1). Some studies have reported lower prevalence of airflow obstruction, with percentages between 3 and 7 [31,59–62], generally in cohorts with younger age and/or lower current or cumulative exposure to tobacco or biomass smoke, though not universally [31]. The few studies that have assessed overlap of radiographic emphysema and airflow obstruction find that emphysema is frequently independent of airflow obstruction [38,52] (Fig. 2), a finding that is also noted in general population studies and that suggests potential differences in pathophysiology [63]. It is worth noting that the presence or absence of radiographic emphysema is dependent on the method used for quantifying the CT data and the selection of a cutoff for ‘normal’ versus ‘abnormal;’ thus, studies including negative controls are particularly useful, but they are rare [38,46].

Table 1

Table 1

Table 1

Table 1

Table 1

Table 1

Fig. 2

Fig. 2

Despite the strong association with smoking in the HIV-uninfected population, HIV-infected persons without smoke exposure also exhibit fixed airflow obstruction [48], and multiple studies have identified HIV infection as an independent risk factor for prevalent COPD [4,5,28,55], radiographic emphysema [64], incident diagnosis of COPD [5], and more frequent COPD exacerbations [65]. These data suggest that HIV infection contributes to COPD independent of usual pathways.

Clinically identifiable risk factors for COPD among individuals with HIV are frequently the same as those in the general population (Table 1). Across most cohorts, older age, and cigarette smoking remain independent risk factors for COPD or airflow obstruction [27,35,41,48–53,62]. Other identified independent factors in some groups have included include low BMI [41,50,59], injection drug use [48,49], history of bacterial pneumonia [27] or colonization [61], PCP [35,49,66], pulmonary TB [52,59], and coinfection with infectious hepatitis C [41,50,66]. The contribution of hepatitis C to airflow obstruction beyond injection drug use remains unclear, and not all studies find an independent effect [67].

HIV-specific risk factors such as ART use, CD4+ cell count, and HIV viral levels have been examined in most studies of HIV and pulmonary function. Two single-center cross-sectional studies found a positive association between ART use and risk of spirometry-defined COPD. The prevalence of ART prescription in these studies was approximately 80%, and CD4+ cell count and HIV viral load were not associated with COPD [27,48]. A recent study assessed pulmonary function trajectories in the Strategic Timing of Antiretroviral Treatment trial [68], an international prospective trial randomizing ART initiation to immediate versus deferred (until CD4+ cell count <350 cells/μl or AIDS developed) in HIV-infected individuals naïve to ART with CD4+ cell counts more than 500 cells/μl [69]. In this trial, there were no differences in spirometry changes or respiratory symptoms between groups, supporting that ART does not directly contribute to worse pulmonary function. Given the trial's enrollment criteria, however, deleterious effects of ART attributable to reconstitution of the immune system in persons with lower nadir CD4+ counts or higher viral loads cannot be ruled out.

Associations with CD4+ cell count have been reported in several studies [30,41,51,64]. In one report, lower CD4+ count was linearly associated with increased odds of COPD [41], whereas in the others, very low CD4+ cell count (<200 cells/μl) were required to demonstrate associations with airflow obstruction [30,51]. All of these cohorts reported high rates of ART prescription (89–98%). A study evaluating risk of emphysema found a nadir CD4+ cell count less than 200 cells/μl significantly associated with risk of radiographic emphysema [64].

Regarding viral load, one study in a cohort of high-risk injection drug uses found that high HIV viral RNA level (>200 000 copies/ml) was associated with obstructive lung disease when comparing with HIV-uninfected participants [47]. Other studies assessing HIV viral load did not use the same stratification methods in analyses, and findings are therefore difficult to compare. Perhaps in contrast to the other reported findings, a study evaluating self-report of COPD exacerbation among IDUs with spirometry-confirmed COPD found that HIV-infected persons with higher CD4+ cell counts (>350 cells/μl) or undetectable HIV viral levels had increased odds of exacerbation when compared with uninfected controls, whereas those with lower CD4+ cell counts or detectable viremia did not [65]. The reasons for these findings are not clear.

Finally, a recent HIV emphysema study found that low CD4+/CD8+ ratio (<0.4), associated with chronic inflammation and T-cell activation in HIV [70], was independently associated with higher odds of emphysema when compared with a high CD4+/CD8+ ratio (>1.0) [58]. Significantly, a small translational study also found lower CD4+/CD8+ ratio in the bronchoalveolar lavage fluid of HIV-infected patients compared with controls [71].

The contradictory results about the impact of HIV-associated variables are likely secondary to differences among cohorts in duration of HIV, level of HIV control, and alternate risk factors, as well as varying methods of analyzing data. In addition, potentially pertinent contributors such as true nadir CD4+ cell counts, periods of ART adherence/nonadherence, and duration of HIV are difficult to capture retrospectively, and may account for unmeasurable differences among participants and between cohorts.

Mechanistic contributors to COPD including oxidative stress, systemic inflammation, cellular senescence, immune activation, and endothelial dysfunction have been evaluated in a smaller number of translational studies. Oxidative stress is a feature of both HIV infection [72] and COPD [73] and has been assessed in basic and translational studies [74–76]. For example, one translational study measuring decreased glutathione, a marker of oxidative stress, in bronchoalveolar fluid collected from persons with and without HIV found HIV infection without ART (compared with HIV-uninfected) to be a risk factor for oxidative stress [77]. How this finding relates to pulmonary function is not yet clear. Systemic inflammation, immune activation, and cellular senescence may be linked in HIV [78–80], with mechanisms including low-level HIV viral persistence [81,82], microbial translocation [83,84], or viral coinfection (CMV [85], EBV [86], hepatitis [87]) as drivers of T-cell or B-cell pattern recognition and stimulation. Elaboration of inflammatory mediators may contribute to COPD; therefore, these links have been assessed in translational studies, below.

Given that COPD in the general population has been associated with dysfunctional systemic inflammation [88,89] that also typifies chronic HIV [90–92], a relationship between the two has also been sought as a possible mechanism of HIV-associated COPD. One cross-sectional study in HIV found increases in peripheral IL-6 and C-reactive protein (CRP) with airflow obstruction, whereas IL-8 was not associated; additionally, surface markers of T-cell activation were associated with abnormal spirometry [93]. IL-6 was similarly associated in another cohort, whereas IL-8 and TNF-α were not [94]. Cellular senescence, also a feature of chronic HIV infection and inflammation, may be important in HIV-related COPD. Shorter telomere length was seen in individuals with worse spirometry in one cross-sectional study [93]. T-cell surface markers of replicative senescence in the same study were paradoxically associated with better spirometry, [93] a phenomenon potentially explained by unique effects of HIV infection on terminal differentiation of effector memory T cells [95]. More recently, investigations have examined monocyte and macrophage activation. The circulating monocyte marker sCD163 was increased in individuals with worse spirometry, [94] and sCD14 was associated with greater risk of radiographic emphysema in persons with HIV, but not in HIV-uninfected persons [64]. High levels of sCD163 have also been associated with incident chronic lung disease in a prospective cohort study of HIV-infected persons; notably, the association between sCD163 and chronic lung disease was strongest in nonsmokers [96]. Similarly, circulating endothelin-1, a biomarker of endothelial dysfunction, was a significant biomarker for airflow obstruction in persons with HIV, but had no relationship to pulmonary function in HIV-uninfected individuals [94]. Taken together, these studies suggest an interaction between monocyte markers, endothelial dysfunction, and other inflammatory pathways and risk of COPD that may be unique to HIV.

Few studies have examined lung function trajectory among persons with HIV, and decline of spirometry measures of lung function has been performed only over relatively short-term follow-up periods [54,94,97,98]. Lung function normally declines with increasing age, but whether lung function declines more rapidly among persons with HIV than those without has not been proven. One prospective study in a high-risk cohort of IDUs enrolling both HIV-infected and uninfected individuals found greater decline among individuals with the highest threshold of viral load (>75 000 copies/ml) and the lowest CD4+ cell counts (<100 cells/μl) when compared with uninfected persons [98]. Certain clinical risk factors beyond HIV-specific variables have been associated with worse trajectory. One study assessing the qualitative assessment of radiographic emphysema over several years of follow-up found that 17% of participants progressed, with risk factors for progression including baseline presence of combined centrilobular and paraseptal emphysema (present in 23% of the cohort), worse diffusing capacity for carbon monoxide (DLCO), high pack-years smoked, male sex, and lower BMI [99]. Although single-center cross-sectional studies found associations between ART use and COPD, a large prospective study evaluating pulmonary function decline in association with initiation of ART found no difference in rate of lung function decline between people randomized to initiate ART at CD4+ cell counts more than 500 cells/μl versus at CD4+ cell counts less than 350 cells/μl [69].

Several mechanisms might contribute to lung function decline in HIV. One study evaluating biomarkers of inflammation, monocyte activation, and endothelial dysfunction in HIV-infected and uninfected participants found that endothelin-1 independently predicted worse airflow obstruction over time in HIV-infected persons; other biomarkers were not significantly associated with decline [94]. Additional research in large cohorts including HIV-infected and uninfected participants, with sustained longitudinal follow-up, is necessary to define the natural history of airflow obstruction in HIV-infected persons and to define modifiable risk factors to reduce the incidence and progression of COPD.

Back to Top | Article Outline

Diffusing impairment

A common measure of pulmonary function, DLCO, is a sensitive surrogate for gas exchange across the alveolar capillary membrane and is associated with functional impairment and with clinical symptoms, including breathlessness and dyspnea on exertion. Reduction of the DLCO may be secondary to destruction of the alveolar interface (from emphysema/COPD), scarring of the interface (interstitial lung disease or fibrosis), or pulmonary vascular disease/cardiopulmonary dysfunction. Diffusing capacity is not always measured as part of routine pulmonary function testing or in the research setting; thus, fewer data are available for DLCO than for spirometry. When DLCO measures have been obtained in HIV cohorts, DLCO deficits are by far the most common pulmonary function abnormality and are in some cases severely abnormal [30,48,52,54,66,94]. HIV has been shown to be an independent risk factor for DLCO impairment in cohorts including HIV-infected and uninfected participants in both the pre-ART and post-ART eras [30,66]. Significantly, whereas in many cases DLCO impairment is seen in association with abnormal spirometry or radiographic emphysema [30,66,99,100] (and therefore likely to represent lung disease), significant DLCO impairment is also found with normal spirometry, suggesting another pathophysiology driving gas exchange impairment in these participants [30,48,66,97] (Fig. 2). Certain cohorts have found diffusing impairment to correlate with abnormal echocardiogram findings, with increased tricuspid regurgitant velocity (TRV) suggesting elevated pulmonary artery pressures or cardiopulmonary dysfunction as a contributor [36,100], but a significant portion of HIV-infected individuals have neither COPD nor cardiac dysfunction to explain their DLCO impairment.

Several characteristics have been found to define diffusing impairment in HIV-infected persons. These include expected pulmonary risk factors, such as smoking, low BMI [30,48,52] and injection drug use, in addition to HIV-specific risk factors, including CD4+ cell counts less than 200 cells/μl [30,66] and CDC stage C HIV [52]. A study that stratified by smoking status (ever-smokers versus nonsmokers) found that among smokers, DLCO was most strongly associated with airflow obstruction and radiographic emphysema, whereas in nonsmokers, forced vital capacity and changes in sputum cell counts were associated with DLCO, supporting different mechanisms of diffusing impairment between groups [100]. Finally, blood markers of diffusing impairment have been evaluated in two studies. In one study including only HIV-infected persons, serum IL-6 and CRP were increased in individuals with worse DLCO, suggesting a Th1 inflammatory component [93]. Another study including both HIV-infected and uninfected participants also found that higher IL-6 and TNF-α were independently associated with worse DLCO. In addition, markers of monocyte activation (sCD163, IL-2 receptor), microbial translocation (lipopolysaccharide), and endothelial dysfunction (endothelin-1) were linked to lower DLCO in HIV-infected individuals [94]. The trajectory of DLCO over time in HIV-infected persons and the degree to which it may be affected by modifiable risk factors remain unclear. One study found diffusing capacity in HIV-infected persons to decline over time [54], whereas another found a paradoxical increase in DLCO over time [94], although the latter was possibly secondary to regression to the mean. This study did not find significant differences in DLCO trajectory between HIV-infected and HIV-uninfected groups, but was performed over a limited period of follow-up and was likely underpowered to detect such differences.

Back to Top | Article Outline

Asthma

Asthma is the most frequent chronic lung disease in the United States, but compared with the data for COPD in HIV, there are far fewer data regarding asthma in adults with HIV. One single-center US study found a very high prevalence of doctor-diagnosed asthma (20.6%) in HIV-infected adults [101]. Another report in the multicenter MACS and WIHS cohorts found that asthma was the most frequent self-reported respiratory diagnosis in each group (13.5% prevalence in MACS and 22.9% in WIHS), although no significant difference in prevalence or incidence of diagnosis was found between HIV-infected and uninfected participants [28]. Administrative data from Canada assessing multimorbidity in HIV (irrespective of pre or post-ART) found a prevalence of asthma claims of 12.7% [102]. In contrast, a cross-sectional study performed in Zimbabwe found a much lower burden of self-reported asthma (4.3%) [103]. Information on risk factors was not available in this study.

Spirometry findings supporting asthma include reversible airflow obstruction evidenced by improvement in airflow in response to bronchodilator, or airway hyper-reactivity detected on bronchoprovocation testing with a bronchial irritant such as methacholine. The US single-center study referenced above found bronchodilator reversibility in 9% of HIV-infected participants [101]. Another cross-sectional study including HIV-infected and uninfected men found a 26.2% prevalence of airway hyper-reactivity in HIV-infected men (versus 14.4% of uninfected controls) [104].

Clinical factors associated with asthma in HIV-infected persons have been assessed. These risks include innate factors such as female sex and family history of asthma, as well as potentially modifiable exposures such as prior history of pneumonia and obesity [28,101]. Significantly, higher BMI was also associated with increased asthma risk, and there appears to be an asthma phenotype of obese HIV-infected women who are at risk for adult-onset asthma. ART use was found to be associated with lower risk of asthma in one study, but data are not conclusive [101]. Biomarkers that have been associated with asthma in HIV include atopic markers such as sputum eosinophils [101] and IgE [104], and inflammatory mediators IL-4 and RANTES [101]. Nontraditional markers associated with chronic HIV infection [101] and adipose-related inflammatory mediators such as adiponectin are also linked to asthma in HIV infection [105]. Adipokines have been related to obesity-related asthma in the general population, and the relationship between adipokines and HIV-associated lipodystrophy suggests possible disease mechanisms which may have been enriched in those with HIV [106].

Back to Top | Article Outline

Pulmonary hypertension and cardiac dysfunction

Pulmonary hypertension has been recognized as a complication of HIV since the pre-ART era, and prevalence estimates suggest that frequency has not significantly changed following ART, remaining at approximately 0.5% of HIV-infected persons [107,108]. Cohort studies in the ART era suggest that elevated pulmonary arterial pressures assessed via echocardiogram were much more common, with clinically significant elevations in the TRV or pulmonary artery systolic pressure (PASP) in 8–35% of participants [36,109,110]. HIV was found to be an independent risk factor for elevated PASP in one of these studies, with seven-fold greater odds of PASP elevation in HIV-infected participants [109]. The significance of elevated pulmonary artery pressures on echocardiogram is not known, and it is unclear if this finding confers a greater risk of developing true pulmonary hypertension in the future.

Reports of association of HIV-related factors with pulmonary hypertension are conflicting, with some studies reporting association with ART or low CD4+ cell count (<200 cells/μl), whereas others do not [36,107,109]. The molecular mechanisms of pulmonary hypertension in HIV remain under investigation, having been linked to viral factors directly via HIV viral proteins contributing to pathogenesis [111–113], and also indirectly with markers of inflammation (IL-6 and IFN-γ) [36] and endothelial dysfunction (asymmetric dimethylarginine [114] and endothelin-1 [115,116]) relating to elevated pulmonary pressures on right heart catheterization or echocardiogram. A recent study of both HIV-infected individuals and a simian immunodeficiency virus-infected nonhuman primate model found a relationship between glutaminolysis and pulmonary hypertension [117]. Other work in animal models and cell lines implicates interactions of HIV and drugs of abuse such as cocaine and opiates in pulmonary hypertension [118–120].

Despite the increased relative risk of pulmonary hypertension in this population, the absolute risk of developing Group 1 pulmonary hypertension remains relatively small. Much more common, and thus likely representing a much greater burden of symptoms, is cardiac dysfunction, including left ventricular (LV) systolic and diastolic dysfunction. Although ‘heart failure’ may not typically be considered a pulmonary disease, the symptoms of cardiac dysfunction overlap considerably with pulmonary abnormalities, and shared risk factors and pathogenesis may underlie cardiac and pulmonary complaints. A study assessing the overlap between cardiac dysfunction and pulmonary function in HIV-infected persons found that elevated PASP and TRV were associated with worse airflow obstruction and worse diffusing capacity, and participants with elevated TRV had increased respiratory symptoms [36]. In HIV-uninfected persons, LV diastolic dysfunction has been found in association with COPD and is associated with worse functional capacity (including 6 MWD) [121], and heart failure syndromes in general are associated with worse diffusing impairment [122], the most common of the HIV-associated pulmonary function abnormalities.

Congestive heart failure is a more frequent diagnosis among persons with HIV than in uninfected controls [123]. A retrospective cohort study from 2011 involving veterans enrolled in the Veterans Aging Cohort Study and the Lung Health Study of Veterans found an adjusted hazard ratio of 1.8 for incident heart failure during approximately 7 years of follow-up. In this cohort, HIV RNA of more than 500 copies/ml was associated with higher risk of heart failure [124]. A follow-up large study of administrative VA data evaluating 98 015 participants without baseline CVD again found an increased risk of incident heart failure diagnoses in association with HIV, with significantly increased hazard ratios for both preserved and reduced ejection fractions. HIV RNA of more than 500 copies/ml was associated with increased risk of heart failure with reduced ejection fraction (HFrEF), and CD4+ cell count less than 200 cells/μl (versus ≥500) was associated with increased risk of both HFrEF and heart failure with preserved ejection fraction. Participants younger than age 40 at baseline had a particularly pronounced risk of incident HF diagnosis [125].

A large ART-era meta-analysis published in 2013, including 11 studies (mean pooled age of participants 42, 21% with hypertension and 23% with active smoking), found reports of LV systolic dysfunction of around 8% and LV diastolic dysfunction around 43%. Predictors of systolic dysfunction in this analysis included elevated high-sensitivity CRP, active tobacco smoking, and prior myocardial infarction. Predictors of diastolic dysfunction included older age and HTN. HIV-associated risk factors such as CD4+ cell count and HIV RNA were not identified as predictors, but most (98%) participants were on ART with undetectable HIV RNA (74%) [126].

Back to Top | Article Outline

Therapies for lung diseases in HIV

Ideal therapies for chronic lung diseases such as COPD, asthma, and pulmonary hypertension in HIV are largely unknown. The majority of trials in these diseases have not included HIV-infected individuals. Standard therapies are therefore generally recommended, but specific concerns exist in the HIV-infected population. In particular, commonly used therapies such as inhaled corticosteroids for COPD and asthma may have more side effects in those with HIV including increased adrenal suppression from interactions with certain antiretroviral agents, mainly ritonavir, and cobicistat [127]. In addition, inhaled corticosteroids are associated with increased risk of bacterial pneumonia [128] and TB [129–131] when used in persons with chronic lung disease in the general population; these concerns are of particular relevance to individuals with existing immune suppression, particularly in regions with higher TB burden. There has been a single published study investigating treatment of COPD specifically in HIV-infected individuals [97]. This study was a small randomized pilot study of rosuvastatin in persons with HIV and airway obstruction or DLCO impairment. It demonstrated a trend of slower decline in airway obstruction and an increase in DLCO after 24 weeks of treatment when compared with placebo, possibly mediated via pleotropic anti-inflammatory effects, including effects on endothelial function [97]. Data in larger cohorts are necessary to confirm this finding.

The greatest opportunity for modification of respiratory disease in the HIV-infected population likely lies in intensifying focus on smoking cessation. In industrialized areas, smoking prevalence among persons with HIV is double that in the general population [132]. Large epidemiologic study estimating attributable mortality associated with smoking in European and North American cohorts suggests that smoking may in fact cause more lost life years than HIV infection itself [133,134]. Quit rates for smokers are significantly less among persons with HIV [132], but the majority of HIV-infected individuals express and interest in quitting and have made at least one quit attempt [135,136]. For HIV-infected persons who smoke, supporting their efforts to quit smoking [137] must be a priority for improving lung health, as well as general health.

Back to Top | Article Outline

Areas of uncertainty and opportunity

Despite an increased recognition of chronic pulmonary disease and symptoms in individuals with HIV infection, there are still many unanswered questions. First, limited longitudinal data exist describing the trajectory of pulmonary function, functional capacity, and mortality among persons with and at risk for lung disease over time. Current data suggest that persons with HIV, particularly those with poor virologic control, experience more rapid decline over time [98]. Longer term prospective data in larger, contemporary cohorts enrolling both infected and well matched uninfected individuals with and without typical pulmonary disease risk factors are needed to better define the course of disease, identify predictors of progressive disease, and identify and confirm targets to reduce the risk and progression of disease. In addition, despite the shared risk factors and physiologic intersection between cardiac dysfunction and pulmonary disease in HIV, and the enhanced focus on multimorbidity in chronically infected patients, very few studies in the literature have directly assessed the overlap between cardiac dysfunction and pulmonary disease and outcomes among persons with HIV. Finally, for persons who are diagnosed with chronic lung disease or respiratory symptoms, aside from the salutary effects of smoking cessation [138], very little data are available regarding clinical care and therapy. These gaps will be very important to address to improve the respiratory health of people living longer with HIV in the current era.

Back to Top | Article Outline

Acknowledgements

The current study is supported by the grant nos. K24 HL123342 (A.M.) and R01 HL096453 (K.M.K.).

Back to Top | Article Outline

Conflicts of interest

There are no conflicts of interest.

Back to Top | Article Outline

References

1. Marcus JL, Chao CR, Leyden WA, Xu L, Quesenberry CP Jr, Klein DB, et al. Narrowing the gap in life expectancy between HIV-infected and HIV-uninfected individuals with access to care. J Acquir Immune Defic Syndr 2016; 73:39–46.
2. Samji H, Cescon A, Hogg RS, Modur SP, Althoff KN, Buchacz K, et al. Closing the gap: increases in life expectancy among treated HIV-positive individuals in the United States and Canada. PLoS One 2013; 8:e81355.
3. Justice AC, Braithwaite RS. Lessons learned from the first wave of aging with HIV. AIDS 2012; 26 (Suppl 1):S11–18.
4. Crothers K, Butt AA, Gibert CL, Rodriguez-Barradas MC, Crystal S, Justice AC. Increased COPD among HIV-positive compared to HIV-negative veterans. Chest 2006; 130:1326–1333.
5. Crothers K, Huang L, Goulet JL, Goetz MB, Brown ST, Rodriguez-Barradas MC, et al. HIV infection and risk for incident pulmonary diseases in the combination antiretroviral therapy era. Am J Respir Crit Care Med 2011; 183:388–395.
6. Gingo MR, Balasubramani GK, Kingsley L, Rinaldo CR Jr, Alden CB, Detels R, et al. The impact of HAART on the respiratory complications of HIV infection: longitudinal trends in the MACS and WIHS cohorts. PLoS One 2013; 8:e58812.
7. Sullivan JH, Moore RD, Keruly JC, Chaisson RE. Effect of antiretroviral therapy on the incidence of bacterial pneumonia in patients with advanced HIV infection. Am J Respir Crit Care Med 2000; 162:64–67.
8. Kohli R, Lo Y, Homel P, Flanigan TP, Gardner LI, Howard AA, et al. Bacterial pneumonia, HIV therapy, and disease progression among HIV-infected women in the HIV epidemiologic research (HER) study. Clin Infect Dis 2006; 43:90–98.
9. Berry SA, Fleishman JA, Moore RD, Gebo KA, Network HIVR. Trends in reasons for hospitalization in a multisite United States cohort of persons living with HIV, 2001–2008. J Acquir Immune Defic Syndr 2012; 59:368–375.
10. Bradley H, Hall HI, Wolitski RJ, Van Handel MM, Stone AE, LaFlam M, et al. Vital Signs: HIV diagnosis, care, and treatment among persons living with HIV – United States, 2011. MMWR Morb Mortal Wkly Rep 2014; 63:1113–1117.
11. Brown J, Lipman M. Community-acquired pneumonia in HIV-infected individuals. Curr Infect Dis Rep 2014; 16:397.
12. Afessa B, Green B. Bacterial pneumonia in hospitalized patients with HIV infection: the pulmonary complications, ICU support, and prognostic factors of hospitalized patients with HIV (PIP) study. Chest 2000; 117:1017–1022.
13. Cohen C, Simonsen L, Sample J, Kang JW, Miller M, Madhi SA, et al. Influenza-related mortality among adults aged 25–54 years with AIDS in South Africa and the United States of America. Clin Infect Dis 2012; 55:996–1003.
14. Peters PJ, Skarbinski J, Louie JK, Jain S, Roland M, Jani SG, et al. New York City Department of Health Swine Flu Investigation. HIV-infected hospitalized patients with 2009 pandemic influenza A (pH1N1) – United States, spring and summer 2009. Clin Infect Dis 2011; 52 (Suppl 1):S183–188.
15. Sheth AN, Althoff KN, Brooks JT. Influenza susceptibility, severity, and shedding in HIV-infected adults: a review of the literature. Clin Infect Dis 2011; 52:219–227.
16. Althoff KN, Anastos K, Nelson KE, Celentano DD, Sharp GB, Greenblatt RM, et al. Predictors of reported influenza vaccination in HIV-infected women in the United States, 2006–2007 and 2007–2008 seasons. Prev Med 2010; 50:223–229.
17. Durham MD, Buchacz K, Armon C, Patel P, Wood K, Brooks JT, et al. Seasonal influenza vaccination rates in the HIV outpatient study-United States, 1999–2013. Clin Infect Dis 2015; 60:976–977.
18. Albalak R, O’Brien RJ, Kammerer JS, O’Brien SM, Marks SM, Castro KG, et al. Trends in tuberculosis/human immunodeficiency virus comorbidity, United States, 1993–2004. Arch Intern Med 2007; 167:2443–2452.
19. Jones JL, Hanson DL, Dworkin MS, DeCock KM. Adult/adolescent spectrum of HIVDG. HIV-associated tuberculosis in the era of highly active antiretroviral therapy. The Adult/Adolescent Spectrum of HIV Disease Group. Int J Tuberc Lung Dis 2000; 4:1026–1031.
20. Suthar AB, Lawn SD, del Amo J, Getahun H, Dye C, Sculier D, et al. Antiretroviral therapy for prevention of tuberculosis in adults with HIV: a systematic review and meta-analysis. PLoS Med 2012; 9:e1001270.
21. Kaplan JE, Hanson D, Dworkin MS, Frederick T, Bertolli J, Lindegren ML, et al. Epidemiology of human immunodeficiency virus-associated opportunistic infections in the United States in the era of highly active antiretroviral therapy. Clin Infect Dis 2000; 30 (Suppl 1):S5–14.
22. Schwarcz L, Chen MJ, Vittinghoff E, Hsu L, Schwarcz S. Declining incidence of AIDS-defining opportunistic illnesses: results from 16 years of population-based AIDS surveillance. AIDS 2013; 27:597–605.
23. Mirza SA, Phelan M, Rimland D, Graviss E, Hamill R, Brandt ME, et al. The changing epidemiology of cryptococcosis: an update from population-based active surveillance in 2 large metropolitan areas, 1992–2000. Clin Infect Dis 2003; 36:789–794.
24. Masannat FY, Ampel NM. Coccidioidomycosis in patients with HIV-1 infection in the era of potent antiretroviral therapy. Clin Infect Dis 2010; 50:1–7.
25. Baddley JW, Sankara IR, Rodriquez JM, Pappas PG, Many WJ Jr. Histoplasmosis in HIV-infected patients in a southern regional medical center: poor prognosis in the era of highly active antiretroviral therapy. Diagn Microbiol Infect Dis 2008; 62:151–156.
26. Myint T, Al-Hasan MN, Ribes JA, Murphy BS, Greenberg RN. Temporal trends, clinical characteristics, and outcomes of histoplasmosis in a tertiary care center in Kentucky, 2000 to 2009. J Int Assoc Provid AIDS Care 2014; 13:100–105.
27. George MP, Kannass M, Huang L, Sciurba FC, Morris A. Respiratory symptoms and airway obstruction in HIV-infected subjects in the HAART era. PLoS One 2009; 4:e6328.
28. Gingo MR, Balasubramani GK, Rice TB, Kingsley L, Kleerup EC, Detels R, et al. Pulmonary symptoms and diagnoses are associated with HIV in the MACS and WIHS cohorts. BMC Pulm Med 2014; 14:75.
29. Campo M, Oursler KK, Huang L, Goetz MB, Rimland D, Hoo GS, et al. Association of chronic cough and pulmonary function with 6-min walk test performance in HIV infection. J Acquir Immune Defic Syndr 2014; 65:557–563.
30. Crothers K, McGinnis K, Kleerup E, Wongtrakool C, Hoo GS, Kim J, et al. HIV infection is associated with reduced pulmonary diffusing capacity. J Acquir Immune Defic Syndr 2013; 64:271–278.
31. Cui Q, Carruthers S, McIvor A, Smaill F, Thabane L, Smieja M. Effect of smoking on lung function, respiratory symptoms and respiratory diseases amongst HIV-positive subjects: a cross-sectional study. AIDS Res Ther 2010; 7:6–16.
32. Drummond MB, Kirk GD, Ricketts EP, McCormack MC, Hague JC, McDyer JF, et al. Cross sectional analysis of respiratory symptoms in an injection drug user cohort: the impact of obstructive lung disease and HIV. BMC Pulm Med 2010; 10:27.
33. Brown J, Roy A, Harris R, Filson S, Johnson M, Abubakar I, et al. Respiratory symptoms in people living with HIV and the effect of antiretroviral therapy: a systematic review and meta-analysis. Thorax 2017; 72:355–366.
34. Voll-Aanerud M, Eagan TM, Plana E, Omenaas ER, Bakke PS, Svanes C, et al. Respiratory symptoms in adults are related to impaired quality of life, regardless of asthma and COPD: results from the European community respiratory health survey. Health Qual Life Outcomes 2010; 8:107.
35. Drummond MB, Huang L, Diaz PT, Kirk GD, Kleerup EC, Morris A, et al. Factors associated with abnormal spirometry among HIV-infected individuals. AIDS 2015; 29:1691–1700.
36. Morris A, Gingo MR, George MP, Lucht L, Kessinger C, Singh V, et al. Cardiopulmonary function in individuals with HIV infection in the antiretroviral therapy era. AIDS 2012; 26:731–740.
37. Singh SJ, Puhan MA, Andrianopoulos V, Hernandes NA, Mitchell KE, Hill CJ, et al. An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease. Eur Respir J 2014; 44:1447–1478.
38. Triplette M, Attia E, Akgun K, Campo M, Rodriguez-Barradas M, Pipavath S, et al. The differential impact of emphysema on respiratory symptoms and 6-minute walk distance in HIV infection. J Acquir Immune Defic Syndr 2017; 74:e23–e29.
39. Brown J, McGowan JA, Chouial H, Capocci S, Smith C, Ivens D, et al. Respiratory health status is impaired in UK HIV-positive adults with virologically suppressed HIV infection. HIV Med 2017; 18:604–612.
40. Leung JM, Liu JC, Mtambo A, Ngan D, Nashta N, Guillemi S, et al. The determinants of poor respiratory health status in adults living with human immunodeficiency virus infection. AIDS Patient Care STDS 2014; 28:240–247.
41. Risso K, Guillouet-de-Salvador F, Valerio L, Pugliese P, Naqvi A, Durant J, et al. COPD in HIV-infected patients: CD4 cell count highly correlated. PLoS One 2017; 12:e0169359.
42. Sigel K, Pitts R, Crothers K. Lung malignancies in HIV infection. Semin Respir Crit Care Med 2016; 37:267–276.
43. Kiderlen TR, Siehl J, Hentrich M. HIV-associated lung cancer. Oncol Res Treat 2017; 40:88–92.
44. Lamprecht B, McBurnie MA, Vollmer WM, Gudmundsson G, Welte T, Nizankowska-Mogilnicka E, et al. COPD in never smokers: results from the population-based burden of obstructive lung disease study. Chest 2011; 139:752–763.
45. Kuhlman JE, Knowles MC, Fishman EK, Siegelman SS. Premature bullous pulmonary damage in AIDS: CT diagnosis. Radiology 1989; 173:23–26.
46. Diaz PT, King MA, Pacht ER, Wewers MD, Gadek JE, Nagaraja HN, et al. Increased susceptibility to pulmonary emphysema among HIV-seropositive smokers. Ann Intern Med 2000; 132:369–372.
47. Drummond MB, Kirk GD, Astemborski J, Marshall MM, Mehta SH, McDyer JF, et al. Association between obstructive lung disease and markers of HIV infection in a high-risk cohort. Thorax 2012; 67:309–314.
48. Gingo MR, George MP, Kessinger CJ, Lucht L, Rissler B, Weinman R, et al. Pulmonary function abnormalities in HIV-infected patients during the current antiretroviral therapy era. Am J Respir Crit Care Med 2010; 182:790–796.
49. Hirani A, Cavallazzi R, Vasu T, Pachinburavan M, Kraft WK, Leiby B, et al. Prevalence of obstructive lung disease in HIV population: a cross sectional study. Respir Med 2011; 105:1655–1661.
50. Makinson A, Hayot M, Eymard-Duvernay S, Quesnoy M, Raffi F, Thirard L, et al. High prevalence of undiagnosed COPD in a cohort of HIV-infected smokers. Eur Respir J 2015; 45:828–831.
51. Akanbi MO, Taiwo BO, Achenbach CJ, Ozoh OB, Obaseki DO, Sule H, et al. HIV associated chronic obstructive pulmonary disease in Nigeria. J AIDS Clin Res 2015; 6:453–458.
52. Samperiz G, Guerrero D, Lopez M, Valera JL, Iglesias A, Rios A, et al. Prevalence of and risk factors for pulmonary abnormalities in HIV-infected patients treated with antiretroviral therapy. HIV Med 2014; 15:321–329.
53. Madeddu G, Fois AG, Calia GM, Babudieri S, Soddu V, Becciu F, et al. Chronic obstructive pulmonary disease: an emerging comorbidity in HIV-infected patients in the HAART era?. Infection 2013; 41:347–353.
54. Kristoffersen US, Lebech AM, Mortensen J, Gerstoft J, Gutte H, Kjaer A. Changes in lung function of HIV-infected patients: a 4.5-year follow-up study. Clin Physiol Funct Imaging 2012; 32:288–295.
55. Nakamura H, Tateyama M, Tasato D, Haranaga S, Ishimine T, Higa F, et al. The prevalence of airway obstruction among Japanese HIV-positive male patients compared with general population; a case–control study of single center analysis. J Infect Chemother 2014; 20:361–364.
56. Guaraldi G, Besutti G, Scaglioni R, Santoro A, Zona S, Guido L, et al. The burden of image based emphysema and bronchiolitis in HIV-infected individuals on antiretroviral therapy. PloS one 2014; 9:e109027.
57. Leader JK, Crothers K, Huang L, King MA, Morris A, Thompson BW, et al. Risk factors associated with quantitative evidence of lung emphysema and fibrosis in an HIV-infected cohort. J Acquir Immune Defic Syndr 2016; 71:420–427.
58. Triplette M, Attia EF, Akgun KM, Soo Hoo GW, Freiberg MS, Butt AA, et al. A low peripheral blood CD4/CD8 ratio is associated with pulmonary emphysema in HIV. PLoS One 2017; 12:e0170857.
59. Pefura-Yone EW, Fodjeu G, Kengne AP, Roche N, Kuaban C. Prevalence and determinants of chronic obstructive pulmonary disease in HIV infected patients in an African country with low level of tobacco smoking. Respir Med 2015; 109:247–254.
60. Onyedum CC, Chukwuka JC, Onwubere BJ, Ulasi II, Onwuekwe IO. Respiratory symptoms and ventilatory function tests in Nigerians with HIV infection. Afr Health Sci 2010; 10:130–137.
61. Nimmo C, Capocci S, Honeyborne I, Brown J, Sewell J, Thurston S, et al. Airway bacteria and respiratory symptoms are common in ambulatory HIV-positive UK adults. Eur Respir J 2015; 46:1208–1211.
62. Kunisaki KM, Niewoehner DE, Collins G, Nixon DE, Tedaldi E, Akolo C, et al. Pulmonary function in an international sample of HIV-positive, treatment-naive adults with CD4 counts > 500 cells/μL: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial. HIV Med 2015; 16 (Suppl 1):119–128.
63. Oelsner EC, Pottinger TD, Burkart KM, Allison M, Buxbaum SG, Hansel NN, et al. Adhesion molecules, endothelin-1 and lung function in seven population-based cohorts. Biomarkers 2013; 18:196–203.
64. Attia EF, Akgun KM, Wongtrakool C, Goetz MB, Rodriguez-Barradas MC, Rimland D, et al. Increased risk of radiographic emphysema in HIV is associated with elevated soluble CD14 and nadir CD4. Chest 2014; 146:1543–1553.
65. Lambert AA, Kirk GD, Astemborski J, Mehta SH, Wise RA, Drummond MB. HIV infection is associated with increased risk for acute exacerbation of COPD. J Acquir Immune Defic Syndr 2015; 69:68–74.
66. Fitzpatrick ME, Gingo MR, Kessinger C, Lucht L, Kleerup E, Greenblatt RM, et al. HIV infection is associated with diffusing capacity impairment in women. J Acquir Immune Defic Syndr 2013; 64:284–288.
67. Fischer WA 2nd, Drummond MB, Merlo CA, Thomas DL, Brown R, Mehta SH, et al. Hepatitis C virus infection is not an independent risk factor for obstructive lung disease. COPD 2014; 11:10–16.
68. Group ISS, Lundgren JD, Babiker AG, Gordin F, Emery S, Grund B, et al. Initiation of antiretroviral therapy in early asymptomatic HIV infection. N Engl J Med 2015; 373:795–807.
69. Kunisaki KM, Niewoehner DE, Collins G, Aagaard B, Atako NB, Bakowska E, et al. Pulmonary effects of immediate versus deferred antiretroviral therapy in HIV-positive individuals: a nested substudy within the multicentre, international, randomised, controlled Strategic Timing of Antiretroviral Treatment (START) trial. Lancet Respir Med 2016; 4:980–989.
70. Serrano-Villar S, Sainz T, Lee SA, Hunt PW, Sinclair E, Shacklett BL, et al. HIV-infected individuals with low CD4/CD8 ratio despite effective antiretroviral therapy exhibit altered T cell subsets, heightened CD8+ T cell activation, and increased risk of non-AIDS morbidity and mortality. PLoS Pathog 2014; 10:e1004078.
71. Popescu I, Drummond MB, Gama L, Coon T, Merlo CA, Wise RA, et al. Activation-induced cell death drives profound lung CD4(+) T-cell depletion in HIV-associated chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2014; 190:744–755.
72. Aukrust P, Muller F, Svardal AM, Ueland T, Berge RK, Froland SS. Disturbed glutathione metabolism and decreased antioxidant levels in human immunodeficiency virus-infected patients during highly active antiretroviral therapy – potential immunomodulatory effects of antioxidants. J Infect Dis 2003; 188:232–238.
73. Kirkham PA, Barnes PJ. Oxidative stress in COPD. Chest 2013; 144:266–273.
74. Lassiter C, Fan X, Joshi PC, Jacob BA, Sutliff RL, Jones DP, et al. HIV-1 transgene expression in rats causes oxidant stress and alveolar epithelial barrier dysfunction. AIDS Res Ther 2009; 6:1.
75. Pacht ER, Diaz P, Clanton T, Hart J, Gadek JE. Alveolar fluid glutathione decreases in asymptomatic HIV-seropositive subjects over time. Chest 1997; 112:785–788.
76. Diaz PT, Wewers MD, King M, Wade J, Hart J, Clanton TL. Regional differences in emphysema scores and BAL glutathione levels in HIV-infected individuals. Chest 2004; 126:1439–1442.
77. Cribbs SK, Guidot DM, Martin GS, Lennox J, Brown LA. Antiretroviral therapy is associated with decreased alveolar glutathione levels even in healthy HIV-infected individuals. PLoS One 2014; 9:e88630.
78. Appay V, Almeida JR, Sauce D, Autran B, Papagno L. Accelerated immune senescence and HIV-1 infection. Exp Gerontol 2007; 42:432–437.
79. Deeks SG. HIV infection, inflammation, immunosenescence, and aging. Annu Rev Med 2011; 62:141–155.
80. Desai S, Landay A. Early immune senescence in HIV disease. Curr HIV/AIDS Rep 2010; 7:4–10.
81. Cockerham LR, Siliciano JD, Sinclair E, O’Doherty U, Palmer S, Yukl SA, et al. CD4+ and CD8+ T cell activation are associated with HIV DNA in resting CD4+ T cells. PloS one 2014; 9:e110731.
82. Hatano H, Jain V, Hunt PW, Lee TH, Sinclair E, Do TD, et al. Cell-based measures of viral persistence are associated with immune activation and programmed cell death protein 1 (PD-1)-expressing CD4+ T cells. J Infect Dis 2013; 208:50–56.
83. Brenchley JM, Price DA, Schacker TW, Asher TE, Silvestri G, Rao S, et al. Microbial translocation is a cause of systemic immune activation in chronic HIV infection. Nat Med 2006; 12:1365–1371.
84. Jiang W, Lederman MM, Hunt P, Sieg SF, Haley K, Rodriguez B, et al. Plasma levels of bacterial DNA correlate with immune activation and the magnitude of immune restoration in persons with antiretroviral-treated HIV infection. J Infect Dis 2009; 199:1177–1185.
85. Hunt PW, Martin JN, Sinclair E, Epling L, Teague J, Jacobson MA, et al. Valganciclovir reduces T cell activation in HIV-infected individuals with incomplete CD4+ T cell recovery on antiretroviral therapy. J Infect Dis 2011; 203:1474–1483.
86. Appay V, Sauce D. Immune activation and inflammation in HIV-1 infection: causes and consequences. J Pathol 2008; 214:231–241.
87. Sajadi MM, Pulijala R, Redfield RR, Talwani R. Chronic immune activation and decreased CD4 cell counts associated with hepatitis C infection in HIV-1 natural viral suppressors. AIDS 2012; 26:1879–1884.
88. Agusti A, Edwards LD, Rennard SI, MacNee W, Tal-Singer R, Miller BE, et al. Persistent systemic inflammation is associated with poor clinical outcomes in COPD: a novel phenotype. PLoS One 2012; 7:e37483.
89. Gadgil A, Duncan SR. Role of T-lymphocytes and pro-inflammatory mediators in the pathogenesis of chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2008; 3:531–541.
90. Armah KA, McGinnis K, Baker J, Gibert C, Butt AA, Bryant KJ, et al. HIV status, burden of comorbid disease, and biomarkers of inflammation, altered coagulation, and monocyte activation. Clin Infect Dis 2012; 55:126–136.
91. Duprez DA, Neuhaus J, Kuller LH, Tracy R, Belloso W, De Wit S, et al. Inflammation, coagulation and cardiovascular disease in HIV-infected individuals. PLoS One 2012; 7:e44454.
92. Funderburg NT. Markers of coagulation and inflammation often remain elevated in ART-treated HIV-infected patients. Curr Opin HIV AIDS 2014; 9:80–86.
93. Fitzpatrick ME, Singh V, Bertolet M, Lucht L, Kessinger C, Michel J, et al. Relationships of pulmonary function, inflammation, and T-cell activation and senescence in an HIV-infected cohort. AIDS 2014; 28:2505–2515.
94. Fitzpatrick ME, Nouraie M, Gingo MR, Camp D, Kessinger CJ, Sincebaugh JB, et al. Novel relationships of markers of monocyte activation and endothelial dysfunction with pulmonary dysfunction in HIV-infected persons. AIDS 2016; 30:1327–1339.
95. Lee SA, Sinclair E, Hatano H, Hsue PY, Epling L, Hecht FM, et al. Impact of HIV on CD8+ T cell CD57 expression is distinct from that of CMV and aging. PLoS One 2014; 9:e89444.
96. Kirkegaard-Klitbo DM, Mejer N, Knudsen TB, Moller HJ, Moestrup SK, Poulsen SD, et al. Soluble CD163 predicts incident chronic lung, kidney and liver disease in HIV infection. AIDS 2017; 31:981–988.
97. Morris A, Fitzpatrick M, Bertolet M, Qin S, Kingsley L, Leo N, et al. Use of rosuvastatin in HIV-associated chronic obstructive pulmonary disease. AIDS 2017; 31:539–544.
98. Drummond MB, Merlo CA, Astemborski J, Kalmin MM, Kisalu A, McDyer JF, et al. The effect of HIV infection on longitudinal lung function decline among IDUs: a prospective cohort. AIDS 2013; 27:1303–1311.
99. Leung JM, Malagoli A, Santoro A, Besutti G, Ligabue G, Scaglioni R, et al. Emphysema distribution and diffusion capacity predict emphysema progression in human immunodeficiency virus infection. PLoS One 2016; 11:e0167247.
100. Gingo MR, He J, Wittman C, Fuhrman C, Leader JK, Kessinger C, et al. Contributors to diffusion impairment in HIV-infected persons. Eur Respir J 2014; 43:195–203.
101. Gingo MR, Wenzel SE, Steele C, Kessinger CJ, Lucht L, Lawther T, et al. Asthma diagnosis and airway bronchodilator response in HIV-infected patients. J Allergy Clin Immunol 2012; 129:708–714. e708.
102. Kendall CE, Wong J, Taljaard M, Glazier RH, Hogg W, Younger J, et al. A cross-sectional, population-based study measuring comorbidity among people living with HIV in Ontario. BMC Public Health 2014; 14:161.
103. Magodoro IM, Esterhuizen TM, Chivese T. A cross-sectional, facility based study of comorbid noncommunicable diseases among adults living with HIV infection in Zimbabwe. BMC Res Notes 2016; 9:379.
104. Poirier CD, Inhaber N, Lalonde RG, Ernst P. Prevalence of bronchial hyperresponsiveness among HIV-infected men. Am J Respir Crit Care Med 2001; 164:542–545.
105. Barton JH, Ireland A, Fitzpatrick M, Kessinger C, Camp D, Weinman R, et al. Adiposity influences airway wall thickness and the asthma phenotype of HIV-associated obstructive lung disease: a cross-sectional study. BMC Pulm Med 2016; 16:111.
106. Freitas P, Carvalho D, Santos AC, Madureira AJ, Martinez E, Pereira J, et al. Adipokines, hormones related to body composition, and insulin resistance in HIV fat redistribution syndrome. BMC Infect Dis 2014; 14:347.
107. Sitbon O, Lascoux-Combe C, Delfraissy JF, Yeni PG, Raffi F, De Zuttere D, et al. Prevalence of HIV-related pulmonary arterial hypertension in the current antiretroviral therapy era. Am J Respir Crit Care Med 2008; 177:108–113.
108. Speich R, Jenni R, Opravil M, Pfab M, Russi EW. Primary pulmonary hypertension in HIV infection. Chest 1991; 100:1268–1271.
109. Hsue PY, Deeks SG, Farah HH, Palav S, Ahmed SY, Schnell A, et al. Role of HIV and human herpesvirus-8 infection in pulmonary arterial hypertension. AIDS 2008; 22:825–833.
110. Mondy KE, Gottdiener J, Overton ET, Henry K, Bush T, Conley L, et al. High prevalence of echocardiographic abnormalities among HIV-infected persons in the era of highly active antiretroviral therapy. Clin Infect Dis 2011; 52:378–386.
111. Almodovar S, Hsue PY, Morelli J, Huang L, Flores SC, Lung HIVS. Pathogenesis of HIV-associated pulmonary hypertension: potential role of HIV-1 Nef. Proc Am Thorac Soc 2011; 8:308–312.
112. Almodovar S, Knight R, Allshouse AA, Roemer S, Lozupone C, McDonald D, et al. Human immunodeficiency virus nef signature sequences are associated with pulmonary hypertension. AIDS Res Hum Retroviruses 2012; 28:607–618.
113. Humbert M. Mediators involved in HIV-related pulmonary arterial hypertension. AIDS 2008; 22 (Suppl 3):S41–47.
114. Parikh RV, Scherzer R, Nitta EM, Leone A, Hur S, Mistry V, et al. Increased levels of asymmetric dimethylarginine are associated with pulmonary arterial hypertension in HIV infection. AIDS 2014; 28:511–519.
115. Feijoo MQ, Toro R, Lopez Vazquez de la Torre M, Lennie V, Arce C, Moreno V, et al. Relationship between endothelin-1 levels and pulmonary arterial hypertension in HIV-infected patients. AIDS 2014; 28:2693–2699.
116. Parikh RV, Ma Y, Scherzer R, Heringer AS, Macgregor JS, Martin JN, et al. Endothelin-1 predicts hemodynamically assessed pulmonary arterial hypertension in HIV infection. PLoS One 2016; 11:e0146355.
117. Bertero T, Oldham WM, Cottrill KA, Pisano S, Vanderpool RR, Yu Q, et al. Vascular stiffness mechanoactivates YAP/TAZ-dependent glutaminolysis to drive pulmonary hypertension. J Clin Invest 2016; 126:3313–3335.
118. Dalvi P, Spikes L, Allen J, Gupta VG, Sharma H, Gillcrist M, et al. Effect of cocaine on pulmonary vascular remodeling and hemodynamics in human immunodeficiency virus-transgenic rats. Am J Respir Cell Mol Biol 2016; 55:201–212.
119. Dalvi P, Wang K, Mermis J, Zeng R, Sanderson M, Johnson S, et al. HIV-1/cocaine induced oxidative stress disrupts tight junction protein-1 in human pulmonary microvascular endothelial cells: role of Ras/ERK1/2 pathway. PLoS One 2014; 9:e85246.
120. Spikes L, Dalvi P, Tawfik O, Gu H, Voelkel NF, Cheney P, et al. Enhanced pulmonary arteriopathy in simian immunodeficiency virus-infected macaques exposed to morphine. Am J Respir Crit Care Med 2012; 185:1235–1243.
121. Lopez-Sanchez M, Munoz-Esquerre M, Huertas D, Gonzalez-Costello J, Ribas J, Manresa F, et al. High prevalence of left ventricle diastolic dysfunction in severe COPD associated with a low exercise capacity: a cross-sectional study. PLoS One 2013; 8:e68034.
122. Guazzi M. Alveolar-capillary membrane dysfunction in heart failure: evidence of a pathophysiologic role. Chest 2003; 124:1090–1102.
123. Barnes RP, Lacson JC, Bahrami H. HIV infection and risk of cardiovascular diseases beyond coronary artery disease. Curr Atheroscler Rep 2017; 19:20.
124. Butt AA, Chang CC, Kuller L, Goetz MB, Leaf D, Rimland D, et al. Risk of heart failure with human immunodeficiency virus in the absence of prior diagnosis of coronary heart disease. Arch Intern Med 2011; 171:737–743.
125. Freiberg MS, Chang CH, Skanderson M, Patterson OV, DuVall SL, Brandt CA, et al. Association between HIV infection and the risk of heart failure with reduced ejection fraction and preserved ejection fraction in the antiretroviral therapy era: results from the veterans aging cohort study. JAMA Cardiol 2017; 2:536–546.
126. Cerrato E, D’Ascenzo F, Biondi-Zoccai G, Calcagno A, Frea S, Grosso Marra W, et al. Cardiac dysfunction in pauci symptomatic human immunodeficiency virus patients: a meta-analysis in the highly active antiretroviral therapy era. Eur Heart J 2013; 34:1432–1436.
127. Foisy MM, Yakiwchuk EM, Chiu I, Singh AE. Adrenal suppression and Cushing's syndrome secondary to an interaction between ritonavir and fluticasone: a review of the literature. HIV Med 2008; 9:389–396.
128. Drummond MB, Dasenbrook EC, Pitz MW, Murphy DJ, Fan E. Inhaled corticosteroids in patients with stable chronic obstructive pulmonary disease: a systematic review and meta-analysis. JAMA 2008; 300:2407–2416.
129. Brassard P, Suissa S, Kezouh A, Ernst P. Inhaled corticosteroids and risk of tuberculosis in patients with respiratory diseases. Am J Respir Crit Care Med 2011; 183:675–678.
130. Chung WS, Chen YF, Hsu JC, Yang WT, Chen SC, Chiang JY. Inhaled corticosteroids and the increased risk of pulmonary tuberculosis: a population-based case–control study. Int J Clin Pract 2014; 68:1193–1199.
131. Lee CH, Kim K, Hyun MK, Jang EJ, Lee NR, Yim JJ. Use of inhaled corticosteroids and the risk of tuberculosis. Thorax 2013; 68:1105–1113.
132. Mdodo R, Frazier EL, Dube SR, Mattson CL, Sutton MY, Brooks JT, et al. Cigarette smoking prevalence among adults with HIV compared with the general adult population in the United States: cross-sectional surveys. Ann Intern Med 2015; 162:335–344.
133. Helleberg M, May MT, Ingle SM, Dabis F, Reiss P, Fätkenheuer G, et al. Smoking and life expectancy among HIV-infected individuals on antiretroviral therapy in Europe and North America. AIDS 2015; 29:221–229.
134. Reddy KP, Parker RA, Losina E, Baggett TP, Paltiel AD, Rigotti NA, et al. Impact of cigarette smoking and smoking cessation on life expectancy among people with HIV: a US-based modeling study. J Infect Dis 2016; 214:1672–1681.
135. Benard A, Bonnet F, Tessier JF, Fossoux H, Dupon M, Mercie P, et al. Tobacco addiction and HIV infection: toward the implementation of cessation programs. ANRS CO3 Aquitaine Cohort. AIDS Patient Care STDS 2007; 21:458–468.
136. Burkhalter JE, Springer CM, Chhabra R, Ostroff JS, Rapkin BD. Tobacco use and readiness to quit smoking in low-income HIV-infected persons. Nicotine Tob Res 2005; 7:511–522.
137. Pacek LR, Cioe PA. Tobacco use, use disorders, and smoking cessation interventions in persons living with HIV. Curr HIV/AIDS Rep 2015; 12:413–420.
138. Vidrine DJ, Arduino RC, Gritz ER. The effects of smoking abstinence on symptom burden and quality of life among persons living with HIV/AIDS. AIDS Patient Care STDS 2007; 21:659–666.
Keywords:

asthma; chronic obstructive; HIV; hypertension; pulmonary; pulmonary disease; ventricular dysfunction

Copyright © 2018 Wolters Kluwer Health, Inc.