HIV This Week

First-year lymphocyte T CD4+ response to antiretroviral therapy according to the HIV type in the IeDEA West Africa collaboration.

Drylewicz J, Eholie S, Maiga M, Zannou DM, Sow PS, Ekouevi DK, Peterson K,Bissagnene E, Dabis F, Thiébaut R; International epidemiologic Databases to Evaluate AIDS (IeDEA) West Africa Collaboration. AIDS. 2010 24:1043-50

The objective of the study was to compare the lymphocyte T CD4+ (CD4) response to combinations of antiretroviral therapy in HIV-1, HIV-2 and dually positive patients in West Africa. The study was a collaboration of 12 prospective cohorts of HIV-infected adults followed in Senegal (2), Gambia (1), Mali (2), Benin (1) and Côte d'Ivoire (6). Nine thousand, four hundred and eighty-two patients infected by HIV-1 only, 270 by HIV-2 only and 321 dually positive, who initiated an antiretroviral therapy. CD4 change over a 12-month period. Observed CD4 cell counts at treatment initiation were similar in the three groups [overall median 155, interquartile range (IQR) 68; 249 cells/microl). In HIV-1 patients, the most common antiretroviral therapy regimen was two nucleoside reverse transcriptase inhibitors and one non-nucleoside reverse transcriptase inhibitor (N = 7714)  as well as for dually positive patients (N = 135). HIV-2 patients were most often treated with a protease inhibitor-based regimen (N = 193) but 45 of them were treated with an non-nucleoside reverse transcriptase inhibitor-containing antiretroviral therapy. In those treated with a non-nucleoside reverse transcriptase inhibitor-containing regimen, the estimated mean CD4 change between 3 and 12 months was significantly  lower in HIV-2 (-41 cells/microl per year) and dually positive patients (+12 cells/microl per year) compared to HIV-1 patients (+69 cells/microl per year, overall P value 0.01). The response in HIV-2 and dually positive patients treated by another regimen (triple nucleoside reverse transcriptase or protease inhibitor-containing antiretroviral therapy) was not significantly different than the response obtained in HIV-1-only patients (all P values >0.30). An optimal CD4 response to antiretroviral therapy in West Africa requires determining HIV type prior to initiation of antiretroviral drugs. Non-nucleoside reverse transcriptase inhibitors are the mainstay of first-line antiretroviral therapy in West Africa but are not adapted to the treatment of HIV-2 and dually positive patients.

For abstract access click here: 

http://journals.lww.com/aidsonline/pages/articleviewer.aspx?year=2010&issue=04240&article=00014&type=abstract

Editor’s note: Non-nucleoside reverse transcriptase inhibitors (NNRTI) are part of first-line regimens in West Africa, the epicenter of the HIV-2 epidemic, but are inappropriate for treatment of HIV-2 infection. Although HIV-2 infection has a longer symptom-free period, lower viral load, and slower disease progression, it can lead to AIDS. This observational study of more than 9000 patients in West Africa found poor CD4+ responses to treatment in patients with HIV-2 infection placed on NNRTI but comparable responses to treatment in people with HIV-2 infection, dual infections, and HIV-1 infection placed on protease inhibitor-containing regimens. This points to the need for medical training, appropriate medications, and diagnostic protocols at clinic level but also underscores the rationale for randomized controlled trials to determine the best drug regimens for patients with HIV-2 infection.