HIV RNA persists in rectal tissue despite rapid plasma virologic suppression with dolutegravir-based therapy : AIDS

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HIV RNA persists in rectal tissue despite rapid plasma virologic suppression with dolutegravir-based therapy

Lahiri, Cecile D.a,b; Brown, Nakita L.a,*; Ryan, Kevin J.c; Acosta, Edward P.c; Sheth, Anandi N.a,b; Mehta, Cyra C.d; Ingersoll, Jessicae; Ofotokun, Ighovwerhaa,b

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doi: 10.1097/QAD.0000000000001945
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Abstract

Background

Despite potent combination antiretroviral therapy (ART), HIV eradication has not been accomplished. HIV persists in reservoirs, defined as a cell type or anatomical site where replication-competent virus accumulates and persists [1]. Gut-associated lymphoid tissue (GALT), the largest component of the human lymphoid organ system [2], remains a suspected HIV reservoir.

Standard of care is lifelong ART, achieving HIV plasma viral load suppression, improvement in immunologic function, and reduction of HIV-associated morbidity. First-line ART recommendations by the Department of Health and Human Services (DHHS) for naive patients include using two nucleoside reverse transcriptase inhibitors (NRTIs) in combination with an integrase strand transfer inhibitor (INSTI) [3]. The second-generation INSTI dolutegravir (DTG, 50 mg daily), is recommended for naive patients in three ART regimens: DTG with tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) or tenofovir alafenamide (TAF)/FTC and the fixed combination DTG/abacavir (ABC)/lamivudine (3TC)] [3]. With unboosted daily dosing and high barrier to resistance, DTG remains an attractive option for providers and patients and is being launched by the World Health Organization as a low-cost once daily generic in low-income and middle-income countries [4].

Despite rapid plasma virologic suppression with INSTIs, HIV RNA viral dynamics within tissues such as the gut have not been well defined. Evidence shows that antiretrovirals may insufficiently penetrate sites outside plasma because of disposition and distribution determined by drug and host factors including sex, physiochemical properties, and membrane transporter effects [5]. For example, rectal tissue concentrations of DTG were less than 20% of plasma in HIV seronegative men [6]. There is conflicting evidence as to whether suboptimal antiretroviral drug penetration impacts reservoir viral dynamics: one study showed an association between lower antiretroviral drug concentrations in lymphatic tissues (including rectum) and persistent HIV replication [7], whereas another study showed no correlation between drug concentrations and HIV RNA or DNA in GALT [8]. Our study aims were two-fold: compare early HIV RNA viral dynamics in plasma and rectal tissue following initiation of DTG-based ART, and explore relationships between rectal tissue HIV RNA decline and DTG exposure in both plasma and rectal tissue. We hypothesized that HIV RNA viral decay would be slower in rectal tissue than plasma and positively correlated with DTG exposure.

Methods

Study design and eligibility criteria

Data was collected from treatment-naïve HIV-infected men and women enrolled into an ongoing 12-week prospective longitudinal cohort study within the Grady Infectious Diseases Program (IDP) in Atlanta, Georgia, USA, between February 2015 and September 2017 (NCT 02924389). A 12-week duration was chosen based on prior data showing that more than 80% of ART-naive patients initiating a DTG-based regimen achieved plasma virologic suppression at 8 weeks [9]. HIV-1 infected adult men and women were recruited from Grady IDP, other HIV clinics within metropolitan Atlanta, and the Atlanta site of the previously described Women's Interagency HIV Study (WIHS) cohort [10] through fliers and interaction with study staff. Eligibility criteria included: age at least 18 years; never having at least 30 consecutive days of ART and none in past 6 months; documented plasma HIV-1 RNA greater than 1000 copies/ml; normal renal and liver chemistries within 90 days; able and willing to give informed consent, able and willing to initiate first-line DTG-ART, and willing to undergo serial blood and rectal tissue sampling. Exclusion criteria included: pregnancy, severe anal/rectal disease, concurrent medications interacting with ART, bleeding diathesis, or medical condition that interfered with study conduct.

Type of DTG-ART was selected and prescribed by the participant's personal HIV provider. Participants were instructed to fill ART at their preferred pharmacy but refrain from starting medication until their first visit. All participants brought their own ARVs to each visit. Participants underwent paired plasma and rectal tissue sampling at four time points: baseline (pre-ART), and post-ART at weeks 2 (Days 7, 10, or 14), 6, and 12. Paired rectal tissue and plasma samples were collected at random times post-ART dosing: 16 of 32 (50%) pairs were collected within 30 min to 6 h postdose, 16 of 32 (50%) of pairs were collected between 12 and 24 h postdose. In addition, intensive plasma pharmacokinetic sampling was performed at DTG first dose and steady state (week 12) at hours 1, 2, 3, 4, 6, 8, 24. Participants were counseled not to place anything per rectum for at least 7 days post-biopsy. Complete blood counts, comprehensive chemistries, and CD4+ lymphocyte counts were performed at baseline and week 12. The Emory University Institutional Review Board (IRB) and the ethics committee for Grady Memorial Hospital (Grady Research Oversight Committee) approved this study. Informed consent was obtained from all study participants prior to study procedures.

Blood and rectal tissue sampling and processing

Study visits occurred either at Grady IDP or Grady Memorial Hospital within the Clinical Research Unit of the Georgia Clinical and Translational Science Alliance. All participants had witnessed administration of DTG-ART at baseline and week 12. At weeks 2 and 6, adherence to ART was self-reported. Blood was obtained via venipuncture in four 10 ml sodium citrate cell preparation tubes and spun at 2300 rpm for 20 min. Plasma was centrifuged again at 2300 rpm for 10 min to remove erythrocytes, then stored at −80 °C. To acquire rectal tissue, a 10 cm plastic anoscope was inserted, rectal mucosa was visualized using a colposcope, and up to eight random punch biopsies (2.3 × 4.2 mm) were obtained using mini-Tischler forceps. Rectal tissue was placed immediately in cryovials, snap frozen in liquid nitrogen, and stored at −80 °C.

HIV-1 RNA quantitation

Plasma and rectal tissue HIV-1 RNA quantitation was performed at the Emory Center for AIDS Research Virology and Molecular Biomarkers Core Laboratory using the Abbott Real-Time HIV-1 Assay with detectable range of 40–10 000 000 copies/ml. The rectal tissue HIV RNA assay was developed and optimized with methodologies used previously in other biological matrices [11]. Rectal tissue was weighed, combined with 500 ml of Promega lysis buffer and 25 μl Abbott Proteinase K, and incubated at 56 oC until dissolved. The supernatant was removed, volume brought up to 1 ml with phosphate-buffered saline, and run on the Abbott Realtime HIV-1 assay with results reported as RNA copies per gram.

Dolutegravir concentrations

DTG plasma and rectal tissue concentrations were measured at the University of Alabama-Birmingham's (UAB) Clinical Pharmacology Laboratory with high performance liquid chromatography-tandem mass spectroscopy (HPLC-MS-MS). DTG plasma concentrations were measured using methods previously developed by our team [12]. DTG and labeled DTG (15N2H7, the internal standard) were extracted from 50 μl human tissue homogenate using protein precipitation with acetonitrile. Extracts were analyzed by reverse-phase chromatography using an ACE Excel 3 C18-PFP column under isocratic conditions at a flow rate of 500 μl/min at 40 °C with mobile phases A and B consisting of 0.1% formic acid in water and 0.1% formic acid acetonitrile, respectively. A triple quadrupole mass spectrometer (AB Sciex 5000) equipped with TurboV IonSpray operating in positive-ion mode was used. Column effluents were analyzed by multiple reaction monitoring (MRM). The precursor/product transitions were 420.1 → 277.3 m/z for DTG and 428.1 → 283.3 m/z for internal standard. The calibration curve was fit using weighted (1/x2) linear regression analysis of DTG/internal standard peak area ratio versus DTG concentration from 5 to 5000 ng/ml. Assays were validated using the Guidance for Industry for US Federal Drug Administration (FDA) regulated studies with 5.5% coefficient of variation and lower and upper limits of quantitation 5–5000 ng/ml or ng/g.

Statistical analyses

Clinical and demographic characteristics were summarized by descriptive statistics with counts and percentages for categorical variables and medians and first and third quartiles (Q1, Q3) or range (minimum–maximum) for continuous variables. Noncompartmental pharmacokinetic analyses were performed for first dose and steady-state DTG using Phoenix Win Nonlin v8.0 (Certara, L.P, St. Louis, Missouri, USA). The area under the plasma concentration curve over the 24-h dosing interval (AUC0–24h) was computed using the linear trapezoidal method. Maximum plasma concentration (Cmax), time to Cmax (Tmax), and plasma concentration at the end of the dosing interval (Cτ) were determined by visual inspection of the plasma concentration time curve. 24-h DTG concentrations were missing for three participants, and interpolated values were determined using the calculated slope of the terminal linear phase. Results below the assay's limit of detection were imputed as zero for first dose pharmacokinetics and half the lower limit of quantitation for steady-state pharmacokinetics. Correlation between repeated measures variables by site were computed from mixed models with random and repeated effects for site.

To calculate DTG rectal : plasma concentration ratios, rectal DTG concentrations were converted from ng/g to ng/ml assuming a tissue density of 1.06 ng/ml, then divided by plasma DTG concentrations. Median rectal tissue DTG concentrations were compared at weeks 2, 6, and 12 using Wilcoxon Signed Rank test.

To determine whether DTG concentrations predicted rectal tissue RNA suppression, we performed two different analyses. First, we developed binary logistic regression models accounting for repeated measures where the event is rectal RNA suppression. A variance component covariance structure was assumed, and log-transformed plasma, rectal, and rectal : plasma DTG concentration ratios were evaluated separately as predictors. Second, we compared pharmacokinetic parameters, including first dose and steady state DTG AUC0–24, and steady-state rectal tissue concentrations at weeks 2, 6, and 12, between those who had baseline detectable rectal tissue HIV RNA and achieved rectal tissue HIV-1 RNA suppression at any time point (rectal tissue suppressors) versus participants with persistent detectable rectal tissue HIV-1 RNA (rectal tissue nonsuppressors) using Wilcoxon Rank Sum Tests. Finally, demographic and clinical characteristics between rectal tissue suppressors and nonsuppressors were compared using chi-square or Fisher's exact tests for categorical variables and Wilcoxon Rank Sum Test for continuous variables.

All statistical analyses were performed using SAS version 9.4 software (Cary, North Carolina, USA), with an alpha level of 0.05.

Role of the funding source

The study sponsors had no role in study design; collection, analysis, and interpretation of data; writing of the report; or in the decision to submit the article for publication.

Results

Demographic and clinical characteristics

Seventy-one individuals were assessed for eligibility; 21 were ineligible (12 not ART-naive, eight had severe anal/rectal disease, one desired other ART), 37 decline to participate, and 13 were enrolled. Twelve participants completed at least two study visits and were included in the analyses. Table 1 summarizes the clinical and demographic characteristics of the study population: six of 12 (50.0%) were women, nine of 12 (75.0%) black, median age was 42.0 years (Q1 31.2, Q3 52.0), and seven of 12 (58.3%) were diagnosed with HIV within the last year. Most common risk factors for HIV acquisition included unprotected heterosexual sex (8/12, 66.7%) and MSM (5/12, 41.6%). Median baseline BMI was 23.3 (Q1 20.2, Q3 29.7), CD4+ cell count 279 cells/μl (Q1 150, Q3 371), and plasma HIV RNA was 4.5 log copies/ml (Q1 3.8, Q3 4.9). Most participants (58.3%) received TDF/FTC as their NRTI backbone.

T1-7
Table 1:
Baseline demographic and clinical characteristics (n = 12).

HIV-1 RNA quantitation

Forty-two paired plasma and rectal tissue samples were available for HIV RNA analysis, with each participant providing at least two pairs. Fifty percent (6/12) of participants had HIV RNA below the assay's limit of detection in plasma by week 2, and all participants (100%) were undetectable in plasma by week 6 (Fig. 1a). In contrast, only four of 12 (33.3%) participants achieved undetectable HIV RNA in rectal tissue at any time point: participant 1 became undetectable at week 12, participant 5 was undetectable at week 6 but had rebound detectable rectal RNA at week 12, and participants 4 and 9 had persistent undetectable rectal RNA at three consecutive time points (Fig. 1b). Median log rectal tissue RNA at weeks 6 and 12 was 5.4 copies/g (Q1, 1.3, Q3, 5.7) and 4.7 (2.0–5.5), respectively.

F1-7
Fig. 1:
HIV-1 RNA viral dynamics over time for n = 12 participants in (a) blood plasma and (b) rectal tissue.Limit-of-assay detection (dashed black line) was 1.6 log copies/ml or copies/g. All participants achieved plasma virologic suppression at week 6 but only 4/12 (33%) achieved rectal tissue virologic suppression at any time-point (participants 1, 4, 5, and 9).

There was discordance of HIV RNA detection in 17 of 42 (40.5%) pairs: 15 of 17 (88.2%) of those pairs had undetectable plasma RNA and detectable rectal RNA and only two of 17 (11.8%) had detectable plasma RNA but undetectable rectal RNA. There was a moderate positive correlation between paired plasma and rectal tissue HIV RNA viral loads, r = 0.59.

Dolutegravir plasma and rectal tissue quantitation

First-dose DTG pharmacokinetic data was available for all 12 participants: median Cmax was 2005 ng/ml (Q1 1170, Q3 2315), Tmax was 1.5 h (Q1 1.0, Q3 3.8), and AUC0–24h was 22,301 h ng/ml (Q1 15,133, Q3 30,845). Steady-state plasma pharmacokinetic data was available for nine of 12 participants: Cmax was 2337 ng/ml (Q1 1842–3035), Tmax 3.0 h (Q1 3.0–4.0), Cτ 560 ng/ml (Q1 435.6, Q3 1210), and AUC0–24h was 27 240 h ng/ml (Q1 24 475, Q3 48 075).

Thirty-two of 42 plasma and rectal tissue pairs were collected after at least 7 days of daily DTG administration and analyzed for steady-state DTG concentrations, with each participant providing at least one pair. DTG was detectable in 31 of 32 pairs (96.9%) of plasma and rectal tissue samples. Median DTG concentrations were significantly higher in plasma compared with rectal tissue at week 2: 1880 ng/ml (Q1 1106, Q3 3921) versus 807 ng/ml (Q1 646, Q3 1420), P = 0.02, and week 6: 2810 ng/ml (Q1 697, Q3 4010) versus 661 ng/ml (Q1 271, Q3 1452), P = 0.007, and nonsignificantly higher at week 12: 1142 ng/ml (Q1 614, Q3 1484) versus 365 ng/ml (Q1 163, Q3 510), P = 0.06. There was a moderate-to-strong positive correlation between paired BP and rectal tissue DTG concentrations: r = 0.76. There were no statistically significant differences in DTG rectal tissue, plasma, or rectal tissue:plasma concentration ratios at time points where rectal tissue RNA was undetectable versus detectable (Table 2).

T2-7
Table 2:
Univariable logistic regression: predictors of rectal tissue HIV RNA suppressiona.

Rectal tissue RNA suppressors versus nonsuppressors

Characteristics of participants with baseline detectable rectal tissue HIV RNA who achieved rectal tissue HIV RNA suppression at any time point, n = 3, were compared with rectal tissue HIV RNA nonsuppressors, n = 8. All three (100.0%) rectal tissue suppressors compared with three of eight (37.5%) nonsuppressors were women. Compared with rectal tissue nonsuppressors, rectal tissue suppressors were older, with a median age of 52.4 years (range 50.5–54.2) versus 36.9 (24.3–53.6), P = 0.05, had higher median baseline BMI, 35.9 kg/m2 (range 24.9–38.5) versus 20.6 (17.7–29.9), P = 0.05, and lower baseline log plasma HIV RNA: 3.7 cop/ml (range 3.6–4.4) versus 4.7 (3.8–5.4), P = 0.02. There was a trend toward lower baseline log rectal tissue HIV RNA in rectal tissue suppressors compared with nonsuppressors: 5.4 log copies/ml (range 4.4–5.6) versus 6.8 (4.9–8.3), P = 0.08 (Table 3). No statistically significant differences were seen between rectal tissue suppressors and nonsuppressors with regard to first dose or steady state plasma AUC0–24 h (Fig. 2), or steady-state rectal tissue concentrations (Table 3).

T3-7
Table 3:
Characteristics of rectal tissue HIV RNA suppressors versus nonsuppressors.
F2-7
Fig. 2:
Median first dose (a) and steady-state (b) dolutegravir (DTG) concentration–time curves in rectal tissue suppressors versus rectal tissue nonsuppressors.Rectal tissue suppressors (n = 3) defined as individuals with baseline detectable rectal tissue HIV RNA who achieved rectal tissue HIV RNA less than 40 copies/g at any time point, rectal tissue nonsuppressors (n = 8) were individuals with persistent detectable rectal tissue HIV RNA. Steady-state pharmacokinetic data available for 3/3 (100%) rectal tissue suppressors and 6/8 (75%) rectal tissue nonsuppressors. No significant differences in first dose or steady-state plasma DTG pharmacokinetic parameters, including maximal concentration (C max), time-to-maximal concentration (t max), concentration at end-of-dosing interval (C τ), or area under the concentration time curve over the 24 h dosing interval (AUC0–24 h) were seen between groups.

Discussion

To our knowledge, this is the first study to show detailed early HIV RNA viral dynamics in plasma and rectal tissue following initiation of DTG-based ART in naive men and women. Plasma virologic suppression with DTG-based therapy was rapid in all participants, consistent with what we know regarding INSTI potency [13]. In contrast, two-third of participants had persistent detectable HIV RNA in rectal tissue, even after achieving plasma virologic suppression. This is consistent with prior data showing recovery of HIV RNA from rectal tissue (ranging from 4.0 to 7.0 log copies RNA/g) at 3 months despite plasma suppression in non-INSTI ART regimens [7]. One-third of participants achieved HIV rectal tissue suppression at some point within the first 12 weeks of DTG-ART. In contrast, Asmuth et al.[8] reported a higher proportion (15/25, 60%) of viral suppression in rectal tissue, but this study evaluated patients after 9 months of ART. Taken together, these data suggest that tissue RNA suppression is possible, albeit at a slower rate than plasma. While the clinical implications of time-to-virologic suppression within tissue remains unclear, it is possible that prolonged HIV persistence in tissue impacts immune activation and inflammatory cascades, potentially contributing to increased morbidity in an aging HIV cohort.

First dose and steady-state DTG AUC0–24h were lower than previously reported data [6,14,15], which may be because of our cohort being older with higher BMI, two factors associated with lower DTG exposure in a population pharmacokinetic study [16]. Median rectal tissue DTG concentrations were lower than paired plasma concentrations at all time points, consistent with literature reporting low rectal tissue concentrations relative to plasma in HIV seronegative men [6]. Effective distribution of drug into lymphatic tissues is dependent on drug physiochemical properties and intestinal expression of efflux transporters. First, hydrophobic drugs with log octanol water partition coefficient, log P, greater than 5 and high molecular weight have greater absorption via the gastrointestinal lymphatic system [17]. DTG lacks these characteristics, with a low molecular weight of 441.36 g/mol and log P of 2.16 [18]. Secondly, the intestinal expression of drug transporters changes with both HIV infection and ART initiation: gene and protein expression of p-glycoprotein is significantly increased in HIV-infected individuals receiving ART [19]. As a result, substrates for this transporter, such as DTG may have reduced transport into intestinal lymphatic tissues.

Despite low-DTG penetration into rectal tissue, neither DTG rectal tissue concentrations nor rectal : plasma concentration ratios were statistically significant predictors of rectal tissue RNA suppression, consistent with findings examining other primary non-INSTI medications [8]. As drug concentration assessments at single time points are limited snapshots of tissue drug exposure, we cannot completely rule out the possibility that suboptimal DTG concentrations affected rectal tissue viral dynamics in this study. Ideally, tissue drug AUC (0–24) over a single dosing interval would be measured; however, given the invasiveness of repeated tissue sampling, this type of analysis would only be possible using a population approach.

Our findings that rectal tissue nonsuppressors had higher baseline plasma and rectal tissue RNA viral loads than rectal tissue-suppressors suggest that these compartments are linked. Higher baseline plasma viral loads (>100 000 copies/ml) are associated with residual low-level viremia detectable by single-copy PCR assays [20], and it is reasonable that this relationship would hold true in tissue sites. The finding of higher BMI in rectal tissue suppressors compared with rectal tissue nonsuppressors is new. Being overweight was associated with lower risk of HIV progression in both HIV-infected women and men [21,22], and higher BMI in women was associated with higher CD4+ cell count and lower mean log viral load [22]. One theory is that the protective effect of obesity may be mediated by the immunomodulatory properties of the hormone leptin [23]. Leptin levels are directly proportional to fat cell mass and tend to be higher in women than men, even at comparable body fat levels [24]. Interestingly, all three rectal tissue suppressors in this study were women. Although studies have shown that women have lower baseline plasma viral loads and faster time to plasma virologic suppression than men [25], sex differences in HIV viral dynamics within tissues such as gut have not been well studied, largely because of the scarcity of women in HIV clinical research [26]. Mechanisms behind these differences have not been elucidated but theories include interactions between sex steroids and the immune system [27]. Although our sample size was too small to conduct sex-stratified analyses, future studies powered to examine sex differences in HIV viral dynamics within tissues are planned.

Our study had several limitations. First, sample size was small with n = 12, limiting our ability to conduct multivariate analyses; nonetheless, participants provided 42 pairs of blood and tissue samples, allowing for robust assessments of viral dynamics and drug exposure not previously assessed in other studies. Second, adherence was self-reported in 50% of study visits, which is prone to recall bias. However, given that all participants attained plasma virologic suppression by week 6 with detectable DTG in 97% of blood and rectal tissue sample pairs, we can conclude that participants were routinely taking ART. Third, insufficient sampling of tissue could affect the ability to detect HIV RNA. Although this is theoretically possible, we quantified HIV RNA in 35 of 42 (83%) of rectal tissue samples, and two participants had undetectable rectal HIV RNA at three sequential time points. These consistent results suggest our findings were accurate and less likely because of inadequate sampling.

Furthermore, we quantitated DTG concentrations from rectal tissue homogenates rather than isolating rectal cells. As tissue homogenates are composed of both extracellular and intracellular components, concentrations overestimate exposure in drugs with intracellular modes of action, such as DTG [28]. However, our study paired tissue homogenate drug concentrations with objective measures of effectiveness (i.e. HIV RNA) at multiple time-points for each patient. Additionally, participants were receiving different NRTI backbones, and we did not measure NRTI drug concentrations. Although ideal, enrolling participants receiving identical NRTI backbones would have been impossible, given the subsequent approval of DTG/ABC/3TC and TAF/FTC mid-study. Although TDF has been shown to attain very high rectal : plasma tissue concentrations compared with other NRTIs [29], three of five (60%) participants in our study receiving TDF/FTC had persistent detectable rectal tissue RNA. Even so, given the increasing use of TAF, an NRTI with significantly lower rectal tissue penetration [30], further studies are needed to assess the impact of TAF exposure on tissue viral dynamics. Finally, we cannot infer from these results whether the HIV RNA recovered is infectious or capable of replication. Studies including quantitative viral outgrowth and infectivity assays are needed and currently underway.

In conclusion, plasma and rectal tissue HIV viral dynamics were discordant in the majority of participants initiating DTG-ART. Neither plasma nor rectal tissue DTG concentrations were statistically significant predictors of rectal tissue HIV RNA suppression, although larger population pharmacokinetic–pharmacodynamic studies are needed to assess the role of tissue drug exposure in tissue viral dynamics or HIV persistence. Future studies should explore mechanisms, particularly sex-mediated, that may explain differences in compartmental HIV viral dynamics and inform strategies to reduce the HIV tissue reservoir.

Acknowledgements

We would like to thank all the participants and staff from the Grady Infectious Diseases Program, the Atlanta Women's Interagency HIV Study, and the Emory Center for AIDS Research (CFAR) Clinical Core for their work on this study.

Author contributions: C.D.L. designed study; assisted with recruitment and enrollment of participants; collected, analyzed, and interpreted data; created all tables and figures; wrote all drafts of the manuscript; N.B. recruited and enrolled participants; collected and interpreted data; reviewed and edited manuscript; K.J.R. developed and validated quantitative dolutegravir assay in rectal tissue; analyzed all pharmacokinetic samples; assisted with data interpretation; wrote portions of the methodology; reviewed and edited the manuscript; E.P.A. designed pharmacokinetic study; analyzed and interpreted pharmacokinetic data; assisted with creation of figures; reviewed and edited the manuscript; A.N.S. assisted with study design, conduct, and data collection; helped interpret the data; reviewed and edited the manuscript; C.C.M. designed statistical analysis plan; conducted statistical analyses and helped interpret data; reviewed and edited the manuscript; J.I. created and validated HIV RNA assay for rectal tissue; performed all quantitative HIV RNA assays on plasma and rectal tissue; wrote portions of the methodology; reviewed and edited the manuscript; I.O. designed study; assisted in study conduct, data collection, and interpretation of results; reviewed and edited the manuscript.

Funding sources: This work was supported by the National Institute of Allergy and Infectious Diseases at the National Institutes of Health (K23AI124913 to C.D.L, K23AI114407 to A.N.S., CFAR P30AI050409, U01 AI103408 to I.O.); National Center for Advancing Translational Sciences at the National Institutes of Health to C.D.L (KL2TR000455 to C.D.L, UL1TR000454); and the Emory Medical Care Foundation.

Conflicts of interest

There are no conflicts of interest.

Presentation of data: Part of this data was presented at the International AIDS Society (IAS) Meeting in Paris, France on 25 July 2017, Session # TUPDB01, Abstract # TUPDB0104.

References

1. Eisele E, Siliciano RF. Redefining the viral reservoirs that prevent HIV-1 eradication. Immunity 2012; 37:377–388.
2. Chun TW, Nickle DC, Justement JS, Meyers JH, Roby G, Hallahan CW, et al. Persistence of HIV in gut-associated lymphoid tissue despite long-term antiretroviral therapy. J Infect Dis 2008; 197:714–720.
3. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Department of Health and Human Services. Available at: https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescent-arv-guidelines/11/what-to-start. [Accessed 3 August 2017]
4. UNAIDS. New high-quality antiretroviral therapy to be launched in South Africa, Kenya and over 90 low-and middle-income countries at reduced price. Available at: http://www.unaids.org/en/resources/presscentre/pressreleaseandstatementarchive/2017/september/20170921_TLD. [Accessed 17 January 2018]
5. Cory TJ, Schacker TW, Stevenson M, Fletcher CV. Overcoming pharmacologic sanctuaries. Curr Opin HIV AIDS 2013; 8:190–195.
6. Greener BN, Patterson KB, Prince HM, Sykes CS, Adams JL, Dumond JB, et al. Dolutegravir pharmacokinetics in the genital tract and colorectum of HIV-negative men after single and multiple dosing. J Acquir Immune Defic Syndr 2013; 64:39–44.
7. Fletcher CV, Staskus K, Wietgrefe SW, Rothenberger M, Reilly C, Chipman JG, et al. Persistent HIV-1 replication is associated with lower antiretroviral drug concentrations in lymphatic tissues. Proc Natl Acad Sci U S A 2014; 111:2307–2312.
8. Asmuth DM, Thompson CG, Chun TW, Ma ZM, Mann S, Sainz T, et al. Tissue pharmacologic and virologic determinants of duodenal and rectal gastrointestinal-associated lymphoid tissue immune reconstitution in HIV-infected patients initiating antiretroviral therapy. J Infect Dis 2017; 216:813–818.
9. Stellbrink HJ, Reynes J, Lazzarin A, Voronin E, Pulido F, Felizarta F, et al. SPRING-1 Team. Dolutegravir in antiretroviral-naive adults with HIV-1: 96-week results from a randomized dose-ranging study. AIDS 2013; 27:1771–1778.
10. Barkan SE, Melnick SL, Preston-Martin S, Weber K, Kalish LA, Miotti P, et al. The Women's Interagency HIV Study. WIHS Collaborative Study Group. Epidemiology 1998; 9:117–125.
11. Loftis A KR, McCall-Culbreath K, Fiscus S, Nelson J. Optimization of Abbott m2000 Realtime HIV-1 viral load assay on breastmilk, dried blood spots, seminal plasma, and cerebrospinal fluid. 5th IAS Conference on HIV Pathogenesis and Treatment.
12. Bennetto-Hood C, Tabolt G, Savina P, Acosta EP. A sensitive HPLC-MS/MS method for the determination of dolutegravir in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 945–946:225–232.
13. Park TE, Mohamed A, Kalabalik J, Sharma R. Review of integrase strand transfer inhibitors for the treatment of human immunodeficiency virus infection. Expert Rev Anti Infect Ther 2015; 13:1195–1212.
14. Adams JL, Patterson KB, Prince HM, Sykes C, Greener BN, Dumond JB, Kashuba AD. Single and multiple dose pharmacokinetics of dolutegravir in the genital tract of HIV-negative women. Antivir Ther 2013; 18:1005–1013.
15. Min S, Sloan L, DeJesus E, Hawkins T, McCurdy L, Song I, et al. Antiviral activity, safety, and pharmacokinetics/pharmacodynamics of dolutegravir as 10-day monotherapy in HIV-1-infected adults. AIDS 2011; 25:1737–1745.
16. Zhang J, Hayes S, Sadler BM, Minto I, Brandt J, Piscitelli S, et al. Population pharmacokinetics of dolutegravir in HIV-infected treatment-naive patients. Br J Clin Pharmacol 2015; 80:502–514.
17. Trevaskis NL, Charman WN, Porter CJ. Lipid-based delivery systems and intestinal lymphatic drug transport: a mechanistic update. Adv Drug Deliv Rev 2008; 60:702–716.
18. Tivicay [package insert]. In: GlaxoSmithKline, ed. Research Triangle Park, NC 2013.
19. Kis O, Sankaran-Walters S, Hoque MT, Walmsley SL, Dandekar S, Bendayan R. HIV-1 alters intestinal expression of drug transporters and metabolic enzymes: implications for antiretroviral drug disposition. Antimicrob Agents Chemother 2016; 60:2771–2781.
20. Zheng L, Bosch RJ, Chan ES, Read S, Kearney M, Margolis DM, et al. DS Clinical Trials Group (ACTG) A5244 Team. Predictors of residual viraemia in patients on long-term suppressive antiretroviral therapy. Antivir Ther 2013; 18:39–43.
21. Shuter J, Chang CJ, Klein RS. Prevalence and predictive value of overweight in an urban HIV care clinic. J Acquir Immune Defic Syndr 2001; 26:291–297.
22. Jones CY, Hogan JW, Snyder B, Klein RS, Rompalo A, Schuman P, Carpenter CC. HIV Epidemiology Research Study Group. Overweight and human immunodeficiency virus (HIV) progression in women: associations HIV disease progression and changes in body mass index in women in the HIV epidemiology research study cohort. Clin Infect Dis 2003; 37 (Suppl 2):S69–S80.
23. Matarese G. Leptin and the immune system: how nutritional status influences the immune response. Eur Cytokine Netw 2000; 11:7–14.
24. Saad MF, Damani S, Gingerich RL, Riad-Gabriel MG, Khan A, Boyadjian R, et al. Sexual dimorphism in plasma leptin concentration. J Clin Endocrinol Metab 1997; 82:579–584.
25. Gandhi M, Bacchetti P, Miotti P, Quinn TC, Veronese F, Greenblatt RM. Does patient sex affect human immunodeficiency virus levels?. Clin Infect Dis 2002; 35:313–322.
26. Johnston RE, Heitzeg MM. Sex, age, race and intervention type in clinical studies of HIV cure: a systematic review. AIDS research and human retroviruses 2015; 31:85–97.
27. Fish EN. The X-files in immunity: sex-based differences predispose immune responses. Nat Rev Immunol 2008; 8:737–744.
28. Mouton JW, Theuretzbacher U, Craig WA, Tulkens PM, Derendorf H, Cars O. Tissue concentrations: do we ever learn?. J Antimicrob Chemother 2008; 61:235–237.
29. Patterson KB, Prince HA, Kraft E, Jenkins AJ, Shaheen NJ, Rooney JF, et al. Penetration of tenofovir and emtricitabine in mucosal tissues: implications for prevention of HIV-1 transmission. Sci Transl Med 2011; 3:112re4.
30. Cottrell ML, Garrett KL, Prince HMA, Sykes C, Schauer A, Emerson CW, et al. Single-dose pharmacokinetics of tenofovir alafenamide and its active metabolite in the mucosal tissues. J Antimicrob Chemother 2017; 72:1731–1740.

* Current affiliation: Emory University School of Medicine, Winship Cancer Center, Atlanta, GA, USA.

Keywords:

antiretroviral pharmacology; dolutegravir; HIV; rectal tissue; reservoirs

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