CCR5 promoter human haplogroups associated with HIV-1 disease progression in Thai injection drug users.

BACKGROUND

An evolutionary-based analysis of the CC chemokine receptor 5 gene (CCR5) promoter region has identified nine stable human haplogroups, within which certain haplogroups appear to influence HIV-1 disease progression differentially among Caucasians and African-Americans.

OBJECTIVE

To assess the influence of CCR5 haplogroups on HIV-1 disease progression in a Thai population.

DESIGN

Haplogroup analysis of HIV-1-seropositive injection drug users (IDU) participating in a prospective cohort study in Bangkok. All were documented seroconverters with a median follow-up time of 3.5 years (range, 0.2-7.0).

METHODS

From a cohort of 130 IDU, 106 (81.5%) were genotyped for the CCR2b-64I, CCR5-delta32 and seven CCR5 promoter alleles constituting the CCR5 haplogroups. Survival curves and adjusted Cox proportional hazards models were used to assess the effect of haplogroups on the time from HIV-1 infection until CD4 count < 200 x 10(6) cells/l.

RESULTS

The most common CCR5 haplogroups were HHC (61.8%), followed by HHE (15.6%) and HHF*2 (14.6%). HHE was associated with an accelerated CD4 count decline to < 200 x 10(6) cells/l (adjusted relative hazard, 1.88; 95% confidence interval, 1.05-3.36; P = 0.02).

CONCLUSIONS

This is the first evidence that the CCR5 haplogroup E speeds the decline of the CD4 cell count and may lead to accelerated disease progression among HIV-infected Thais. These new observations highlight the need for additional studies involving populations in Asia.