Impact of ethnicity and HIV type 1 subtype on response to first-line antiretroviral therapy

A distinct effectiveness of highly active antiretroviral therapy (HAART) in HIV-infected patients across ethnicities may reflect differences in drug adherence, host genetic factors, and/or predominant HIV subtypes. We investigated the immunologic outcome in 79 drug-naive HIV individuals living in Madrid, 39 of whom were African immigrants, who achieved and maintained undetectable viral load for up to 24 months following initiation of HAART. Overall, 90% of whites were infected with clade B viruses while 80% of Africans carried non-B subtypes. Gender, age, mean baseline viral load, and CD4 counts were comparable in both groups. The mean time to reach undetectable viremia did not differ significantly between groups. CD4 gains at 24 months following HAART initiation were also similar, although Africans showed higher CD4 gains than whites at month 12. In a multivariate analysis neither HIV subtype nor ethnicity was associated with different CD4 gains at any given time point, suggesting that reconstitution of CD4+ T cells under HAART is not influenced by ethnicity.