459 Peculiarities of HIV-specific Immune Response in Discordant Couples

BACKGROUND: In HIV discordant couples (one parther is HIV-infected, another is HIV-uninfected) HIV-negative partners often remain uninfected for a long time despite long, stable, often unprotected sexual contacts with HIV-infected partner. The increase of time of living together accompanying the decrease of the incidence of HIV infection in HIV-negative partner. The features of HIV-specific immune response in HIV discorgant couples was investigated. METHODS: Thirty-three HIV discordant couples from Moscow region living together <1 year (2 couples), 1 to 3 years (18 couples), 4 to 5 years (9 couples), 6 to 10 years (4 couples) were included in the investigation. Sera of 33 HIV-uninfected partners from HIV discordant couples (17 men and 16 women) were tested for HIV-specific antibodies by enzyme immunoassay and immunoblot. Viral load was estimated by polymerase chain reaction (PCR). RESULTS: Antibodies against HIV gp160 were detected in 3 persons (9,1%), against p68/66—in 3 persons (9,1%), against p52/51—in 3 persons (9,1%), against g34/31—in 3 persons (9,1%); total—in 6 persons (18,2%). All of them were defined as HIV-uninfected by PCR. In 4 of 6 persons HIV-specific antibodies were not detected after finishing of risk behavior. CONCLUSIONS: It is possible to suggest that detected antibodies against HIV gp160, p68/66, p52/51, p34/31 in HIV-uninfected people are caused by contact with HIV (according to literature data, non-specific stimulation may cause the appearance of antibodies binding the other HIV antigens: p55, p24/25 and g18) and may contribute to maintainance of HIV-negative status of uninfected partners in HIV-discordant couples. The cohort of high exposed but HIV-uninfected people was formed during immunological monitoring of HIV discordant couples in Moscow region. This cohort is available for systematic observation and is perspective for further investigation of mechanisms of resistance to HIV infection and correlates of immune protection. Now the cohort is expanded.