HLA B*5701 status, disease progression, and response to antiretroviral therapy

Objective:In addition to hypersensitivity reactions to abacavir, HLA B5701 has been associated with slow or nonprogression of HIV infection. We explored the effect of HLA B5701 on CD4(+) cell count and viral load in untreated patients and on responses to nonabacavir-containing combination antiretroviral therapy (cART) in a large UK-based cohort.Design:Analysis of a cohort of HIV-infected adults.Methods:In untreated patients, CD4(+) cell count and viral load at study entry were compared in HLAB5701-positive and HLAB5701-negative individuals and linear regression tested for an interaction effect of viral load and HLA B5701 on CD4(+) cell count. In patients starting a nonabacavir cART regimen, Cox proportional hazards models compared virological responses to cART among HLA B5701-negative, HLA B5701-positive, and those not tested. Six-month and 12-month changes in CD4(+) cell count were used as outcomes in linear regression to compare immunological response to cART in these groups.Results:ART-naive HLA B5701-positive individuals had higher CD4(+) cell count (P<0.0001) and lower viral load (P<0.0001) at study entry than negatives; however, HLA B5701 status was not found to effect the association between viral load and CD4(+) cell count (interaction P value=0.09). HLA B5701-positive patients were more likely to achieve viral suppression than negative patients on a nonabacavir regimen [hazard ratio=1.29, 95% confidence interval, CI (1.15-1.54)] and less likely to experience viral rebound [hazard ratio=0.61, 95% CI (0.37-0.99)].Conclusion:Better virological but not immunological responses to cART were seen in HLA B5701-positive patients on nonabacavir regimens. This study provides further evidence of the potentially beneficial effect of HLA B5701 on HIV progression. (C) 2013 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins