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AIDS:
doi: 10.1097/QAD.0b013e328359ab2f
Correspondence

Discussion on the effect of age on immunological response in the first year of antiretroviral therapy in HIV-1-infected adults

Thiébaut, Rodolphea,b; Eholié, Sergec; Dabis, Françoisa,b

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aUniversité Bordeaux Segalen, ISPED, Centre INSERM U897-Epidemiologie-Biostatistique

bINSERM, ISPED, Centre INSERM U897-Epidemiologie-Biostatistique, Bordeaux, France

cService de Maladies Infectieuses et Tropicales, Centre Hospitalier Universitaire de Treichville, Abidjan, Côte D’Ivoire, West Africa.

Correspondence to Rodolphe Thiébaut, ISPED, INSERM U897, Université de Bordeaux Segalen, 146 Rue Leo Saignat, 33076 Bordeaux Cedex, France. Tel: +33 5 57 57 45 21; fax: +33 5 56 24 00 81; e-mail: rodolphe.thiebaut@isped.u-bordeaux2.fr

Received 7 August, 2012

Accepted 23 August, 2012

da Rocha et al.[1] stressed their interest in the large data base results we presented on HIV-infected patients starting a treatment in the International epidemiological Database to Evaluate AIDS (IeDEA) West Africa Collaboration: the older they are, the poorer their CD4 response to antiretroviral treatment (ART) [2]. They pinpointed two factors that may play a role in the type and level of CD4 response: tuberculosis infection and duration of HIV infection. Indeed, tuberculosis, like other opportunistic infections [3,4], impairs the immune response. The duration of HIV infection has also been reported as an important determinant of the CD4 response to ART [5,6]. When looking at the age effect on the CD4 response, the key point is whether these latter factors play the role of confounding factors or effect modifiers in this association. Hence, with the association between age and tuberculosis being inconsistently described [7], it is not granted that the measure of the age effect without adjustment for tuberculosis should be biased. Conversely, the duration of HIV infection may indeed confound or modify the effect of age [8], but the information of time of seroconversion is not available in this large data set collected under routine circumstances for more than a dozen of clinics throughout West Africa.

Rocha et al.[1] were also concerned by the high percentage of losses for the second point of CD4 measurement’. This underlines the general issue of patients being lost to follow-up in many Africa clinics as we recently highlighted within the IeDEA Collaboration [9], and this phenomenon could impair estimates because of informative censoring. Innovative approaches have been proposed to chase additional information on these patients [10,11] but were not systematically used in our network. Several sensitivity analyses have been done in the present study to check the robustness of our estimates and were favourable. Also, one should keep in mind that excluding patients with only one measurement may lead to a larger bias than including them using relevant statistical methods, as explained in more detail elsewhere [12].

In conclusion, our published results should certainly be confirmed in other studies throughout sub-Saharan Africa, with a longer follow-up and taking into account as many determinants as possible of CD4 response. Large networks such as the IeDEA Collaboration are best suited for addressing this type of question (http://www.iedea.org/).

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Acknowledgements

Conflicts of interest

There are no conflicts of interest.

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References

1. da Rocha NT, Duarte BS, Wolff DW, Barcellos FH. Factors that also interfere in CD4 levels and can be considered on analizing the effect of age on immunological response of antiretroviral therapy.AIDS 2012.

2. Balestre E, Eholié S, Lokossue A, Sow P, Charurat M, Minga A, et al. Effect of age on immunological response in the first year of antiretroviral therapy in HIV-1-infected adults in West Africa. AIDS 2012; 26:951–957.

3. Cingolani A, Cozzi Lepri A, Castagna A, Goletti D, De Luca A, Scarpellini P, et al. Impaired CD4 T-cell count response to combined antiretroviral therapy in antiretroviral-naive HIV-infected patients presenting with tuberculosis as AIDS-defining condition. Clin Infect Dis 2012; 54:853–861.

4. Lazaro E, Coureau G, Guedj J, Blanco P, Pellegrin I, Commenges D, et al. the ANRS Co3 Aquitaine CohortChange in T lymphocytes count after HAART initiation in HIV-infected patients with history of Mycobacterium avium complex infection. Antivir Ther 2006; 11:343–350.

5. Babiker A, Darbyshire J, Pezzotti P, Porter K, Prins M, Sabin C, Walker AS. CASCADE CollaborationShort-term CD4 cell response after highly active antiretroviral therapy initiated at different times from seroconversion in 1500 seroconverters. J Acquir Immune Defic Syndr 2003; 32:303–310.

6. Lodi S, Phillips A, Touloumi G, Geskus R, Meyer L, Thiébaut R, et al. CASCADE Collaboration in EuroCoordTime from human immunodeficiency virus seroconversion to reaching CD4+ cell count thresholds <200, <350, and <500 Cells/mm3: assessment of need following changes in treatment guidelines. Clin Infect Dis 2011; 53:817–825.

7. Fenner L, Forster M, Boulle A, Phiri S, Braitstein P, Lewden C, et al. ART-LINC of IeDEATuberculosis in HIV programmes in lower-income countries: practices and risk factors. Int J Tuberc Lung Dis 2011; 15:620–627.

8. Thiébaut R, Jacqmin-Gadda H, Walker S, Sabin C, Prins M, Del Amo J, et al. CASCADE CollaborationDeterminants of response to first HAART regimen in antiretroviral-naive patients with an estimated time since HIV seroconversion. HIV Med 2006; 7:1–9.

9. Chi BH, Yiannoutsos CT, Westfall AO, Newman JE, Zhou J, Cesar C, et al. International Epidemiologic Databases to Evaluate AIDS CollaborationUniversal definition of loss to follow-up in HIV treatment programs: a statistical analysis of 111 facilities in Africa, Asia, and Latin America. PLoS Med 2011; 8:e1001111.

10. Geng EH, Emenyonu N, Bwana MB, Glidden DV, Martin JN. Sampling-based approach to determining outcomes of patients lost to follow-up in antiretroviral therapy scale-up programs in Africa. JAMA 2008; 300:506–507.

11. Rosen S, Fox MP. Retention in HIV care between testing and treatment in sub-Saharan Africa: a systematic review. PLoS Med 2011; 8:e1001056.

12. Thiébaut R, Walker S. When it is better to estimate a slope with only one point. QJM 2008; 101:821–824.

© 2013 Lippincott Williams & Wilkins, Inc.

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