HIV-1 viral subtype differences in the rate of CD4⁺ T-Cell decline among HIV seroincident antiretroviral naive persons in rakai district, Uganda

BACKGROUND: Data on the effect of HIV-1 viral subtype on CD4 T-cell decline are limited. METHODS: We assessed the rate of CD4 T-cell decline per year among 312 HIV seroincident persons infected with different HIV-1 subtypes. Rates of CD4 decline by HIV-1 subtype were determined by linear mixed effects models, using an unstructured convariance structure. RESULTS: A total of 59.6% had D, 15.7% A, 18.9% recombinant viruses (R), and 5.8% multiple subtypes (M). For all subtypes combined, the overall rate of CD4 T-cell decline was-34.5 [95% confidence interval (CI),-47.1,-22.0] cells/μL per yr, adjusted for age, sex, baseline CD4 counts, and viral load. Compared with subtype A, the adjusted rate of CD4 cell loss was-73.7/μL/yr (95% CI,-113.5,-33.8, P < 0.001) for subtype D,-43.2/μL/yr (95% CI,-90.2, 3.8, P = 0.072) for recombinants, and-63.9/μL/yr (95% CI,-132.3, 4.4, P = 0.067) for infection with multiple HIV subtypes. Square-root transformation of CD4 cell counts did not change the results. CONCLUSIONS: Infection with subtype D is associated with significantly faster rates of CD4 T-cell loss than subtype A. This may explain the more rapid disease progression for subtype D compared with subtype A.