Among the subset of women who showed a 2-fold increase in HAV antibody concentrations after vaccination, the GMFR was 8.7 (95% CI of 7.1, 10.7). by downregulation of T-cell immunity. We evaluated the effect of hormonal contraception (HC) and of CD4 cell numbers and plasma HIV RNA load on antibody responses to HAV vaccine of HIV-infected women. Methods AZD3988 The study used archived samples collected between Nov 1994 and Feb 2010 from women enrolled in the prospective observational Women’s AZD3988 Interagency HIV Study (WIHS)27,28. There are two recommended schedules of immunization against HAV (2 or 3 3 doses separated by 6 or 2 months, respectively) with FDA-licensed vaccines from two manufacturers, but the antibody responses after the last dose of vaccine are similar in immunocompetent hosts, regardless of product or administration regimen29-33. In this study, we made no distinction between products or regimens. Quantitative HAV antibodies measurements were performed according to the manufacturer’s instructions using a pseudo-competitive enzyme immunoassay kit (Mediagnost) with a dynamic range of 10 to 50 mIU/ml. Samples with titers 50 mIU/ml were diluted until a measurement within the dynamic range of the test was obtained. Peak antibody titer was defined as the highest measurement observed after vaccination was reported. Antibody measurements were truncated at 20 mIU/ml, which is the threshold for vaccine-induced protection and for seropositivity. Samples with 20 mIU/ml were ascribed an arbitrary value of 10 mIU/ml. Response on the continuous scale was defined as Log10 of the ratio of peak/baseline antibody concentration. Response was also analyzed as a dichotomous outcome. In HAV-seronaive subjects (baseline 20 mIU/ml), a peak antibody titer 20 mIU/ml defined response. In HAV-experienced subjects (baseline titer 20 mIU/ml), response was defined by 2-fold increase in antibody concentration at peak compared with baseline. Subjects were defined as HC recipients if they reported HC at baseline and subsequent visit. Subjects with discrepant HC reports at the two above-mentioned visits were excluded from the analysis. Differences between HC and non-HC recipients were analyzed using two-sample t-test or chi-square in SAS 9.2 (SAS Institute). Multivariate analyses used logistic regression. Results Among 373 women who met inclusion criteria, 36 (10%) used HC at the time of vaccination, including 18 on oral contraceptives, 17 on depo-medroxyprogesterone acetate and one with alternate use of both methods. Women who used HC were younger than those who did not (meansSD of 376 vs. 428 years; p 0.001). Other characteristics were similar including race and ethnicity (14% white, 31% Hispanics and 56% black); mode of HIV acquisition (21% intravenous drug use; 47% heterosexual; 2% transfusion; 19% unknown); CD4 cells/l (meanS.D.=478265); plasma HIV RNA 400 copies/ml (47%); use of HAART (78%) and HAV-seropositivity before vaccination (57%). Baseline antibody titers AZD3988 were similar in HC and non-HC recipients [GM (95% GMCI) of 197.7 (88.2, 443.0) and 135.6 (105.3, 174.4) mIU/ml, respectively; p=0.37]. The magnitude of the peak antibody titer was also similar in the 2 2 groups: 504.8 (252.1, 1010.7) and 324.1 (254.9, 412.2) mIU/ml for HC and non-HC, AZD3988 respectively (p=0.22). Overall, 44% of the 36 HC and 39% of the 337 non-HC recipients responded to vaccination. Among 162 baseline-HAV-na?ve participants (titers 20 mIU/ml), 62% of the 13 HC and 51% of the 149 non-HC recipients were responders. Among 211 baseline seropositive participants, 30% had a booster response to vaccination, including 35% of 23 HC recipients and 30% of 188 non-HC participants. Overall, the geometric mean fold-rise (GMFR) in HAV antibody titers after vaccination was 2.4 (95% CI of 2.1, 2.8). Among MGC18216 the subset of women who showed a 2-fold increase in HAV antibody concentrations after vaccination, the GMFR was 8.7 (95% CI of 7.1, 10.7). The GMFR did not significantly differ between HC and non-HC recipients overall (p=0.78) or between HC and non-HC responders (p=0.75). The table shows the predictors of HAV response investigated in this study. In the univariate analysis, white race,.