A common CD4 gene variant is associated with an increased risk of HIV-1 infection in Kenyan female commercial sex workers.

Background: It has been predicted that CD4 C868T, a novel CD4 single-nucleotide polymorphism (SNP) that has been found to be highly prevalent among Africans, changes the tertiary structure of CD4, which may alter susceptibility to human immunodeficiency virus (HIV) infection.

Methods: Participants were from a Kenyan cohort and included 87 uninfected and 277 HIV-1-infected individuals. DNA sequencing was used to determine CD4 genotype. A2.01 cells expressing similar levels of either wild-type CD4 or CD4-Trp240 as well as peripheral blood mononuclear cells from uninfected donors were infected with HIV-1(IIIB) or a Kenyan primary HIV-1 isolate. HIV-1 p24 enzyme-linked immunosorbent assay was used to determine the outcome of infection.

Results: CD4 C868T was found to be significantly more prevalent among HIV-1-infected participants than among HIV-1-uninfected participants (P = .002), and C868T was associated with an increased incidence of HIV-1 infection as well (P = .005, log-rank test; P = .009, Wilcoxon test), with an odds ratio of 2.49 (P = .009). Both in vitro and ex vivo models demonstrated a significant association between CD4 C868T and susceptibility to HIV-1 infection (P < .001 and P = .003, respectively).

Conclusion: Overall, the present study found a strong correlation between CD4 C868T and increased susceptibility to HIV-1 infection. Given the high prevalence of both HIV infection and CD4 C868T in African populations, the effect of this SNP on the epidemic in Africa could be dramatic.