HIV-1–Specific Immune Responses and Infection Risk

Carlos del Rio, MD reviewing Kuebler PJ et al. Proc Natl Acad Sci U S A 2015 Jun 22.

For individuals exposed to the virus, HIV-1–specific T-cell immunity may be important in predicting risk for — and protecting against — subsequent infection.

It is known that some HIV-1–exposed but uninfected individuals have HIV-1–specific immune responses, but what these responses mean remains unclear. Now, researchers have conducted a case-control study involving participants in the iPrEx trial (NEJM JW AIDS Clin Care Jan 2011and N Engl J Med 2010; 363:2587) to examine the relation between preinfection HIV-1 immune response and risk for subsequent infection.

Eighty-four preinfection peripheral blood mononuclear cell samples from participants who seroconverted were matched with 480 samples from those who remained seronegative. Although anti–HIV-1 responses were seen in both groups (63% and 72%, respectively; P=0.72), the nature of these responses differed. Higher-magnitude T-cell responses to viral infectivity factor and integrase antigens were associated with reduced risk for HIV-1 infection (hazard ratios, 0.36 and 0.52, respectively), independent of antiretroviral use. In contrast, higher-magnitude responses to protease antigens were associated with increased infection risk (HR, 2.50).

Citation(s):

Kuebler PJ et al. Cellular immune correlates analysis of an HIV-1 preexposure prophylaxis trial. Proc Natl Acad Sci U S A 2015 Jun 22;[e-pub].