Human leukocyte antigen B58 supertype and human immunodeficiency virus type 1 infection in native Africans

HIV-infected Rwandan women have a high frequency of long-term survival

OBJECTIVES

To evaluate rates of long-term survival in a prospective, longitudinal, closed HIV cohort in Africa between 1986 and 2006.

METHODS

A total of 548 HIV-infected Rwandan women were recruited from prenatal clinics in Kigali and followed at 3-6 month intervals to February 2006. Overall, 401 women (73%) were HIV positive at initial cross-sectional testing in 1986 (seroprevalent cohort) and 147 women (27%) were initially HIV negative but seroconverted during follow-up from 1986 to 1993 (seroincident cohort). Kaplan-Meier survival methods were used to calculate survival times censored in mid-2003.

RESULTS

In February 2006, 109 women (20%) remained alive in the cohort. Time to 50% non-genocide mortality was 11.9 years among seroincident women and 8.9 years among seroprevalent women. Smoothed mortality rates increased with duration of follow-up to a peak of 0.12 deaths per person-year at 9.5 years of follow-up but subsequently declined. After 15 years of follow-up (pre-HAART introduction), the survival probability was 36% for seroincident women and 26% for seroprevalent women. Most survivors had virological and immunological evidence of disease progression. The median CD4 cell count of survivors declined from 447 cells/mul in 1998 to 268 cells/mul in 2003. Among survivors, 57 women (52%) met treatment criteria and initiated antiretroviral treatment by 2006.

CONCLUSION

Although median survival times in this cohort were similar to those observed in high-income countries, the rates of long-term survival after 15 years of follow-up were higher than expected. A levelling off of mortality rates during the late stages of follow-up may explain this high rate of long-term survival.

Compensatory mutation partially restores fitness and delays reversion of escape mutation within the immunodominant HLA-B*5703-restricted Gag epitope in chronic human immunodeficiency virus type 1 infection

HLA-B*5703 is associated with effective immune control in human immunodeficiency virus type 1 (HIV-1) infection. Here we describe an escape mutation within the immunodominant HLA-B*5703-restricted epitope in chronic HIV-1 infection, KAFSPEVIPMF (Gag 162-172), and demonstrate that this mutation reduces viral replicative capacity. Reversion of this mutation following transmission to HLA-B*5703-negative recipients was delayed by the compensatory mutation S165N within the same epitope. These data may help explain the observed association between HLA-B*5703 and long-term control of viremia.