Prevalence of and risk factors for tuberculin positivity and skin test anergy in HIV-1-infected and uninfected at-risk women

Objectives: To determine differences in rates of reactivity to purified protein derivative (PPD) tuberculin and of skin test anergy in relationship to serostatus, immune status, demographic characteristics, and other risk factors in women infected with or at high risk for infection with HIV-1; and to compare the usefulness of three different antigens in assessing delayed type hypersensitivity. Design/Methods: Cross-sectional analysis of baseline data in a multicenter prospective cohort study of 1343 HIV-1-seropositive and 390 seronegative but at-risk women recruited from sites of HIV primary care and through community-based outreach for a longitudinal cohort study. Results: 4.7% of the 1343 HIV-1-seropositive women and 15.4% of the 390 HIV- seronegative women were tuberculin-positive (p < .001). A lower threshold in millimeters of induration for tuberculin reactivity among HIV-seropositive women resulted in a smaller difference between the seropositive and the seronegative groups. Even when a 2-mm threshold was used in HIV-seropositive respondents, with a 10-mm threshold among seronegative participants, the difference between the seropositive (6.9% reactive) and the seronegative (15.4% reactive) groups remained statistically significant (p < .001). Limiting analysis to women who responded to the non-PPD antigens did not eliminate the differences in PPD reactivity between the HIV-seropositive and HIV-seronegative women. In multivariate analysis, tuberculin reactivity was associated with HIV-negative serostatus, a history of tuberculosis infection or disease, geographic site, and CD4 count >200 cells/mm³ in the HIV- seropositive women. In all, 41% of HIV-seropositive women and 12% of seronegative women were anergic (p < .001). Candida antigen had the lowest response rates. In multivariate analyses, only HIV-serostatus and CD4 cell counts in HIV-seropositive women were significantly associated with anergy. Conclusions: In this community-based cohort of HIV-seropositive and HIV- seronegative women, we found significant differences between the seronegative and seropositive women even with a lower threshold of induration defining PPD reactivity among seropositive women and among women not anergic to the non- PPD antigens. Prevalence of PPD reactivity was higher than in previously described in cohorts of homosexual men, but lower than in cohorts of predominantly male injection drug users. Rates of anergy were similar to those in most previously described cohorts.