Delayed-type hypersensitivity testing in Tanzanian adults with HIV infection.

Delayed-type hypersensitivity (DTH) testing and total lymphocyte counts as measures of cell-mediated immune function were assessed for medical patients in Dar es Salaam, Tanzania. DTH testing was performed with the Multitest CMI device which simultaneously administers seven antigens. Of 201 patients completing DTH testing, 90 were HIV seropositive. Anergy occurred more frequently among HIV-seropositive patients (39 of 90) as compared with HIV-seronegative patients (17 of 111). DTH skin test reactivity, measured by anergy, the number of positive antigens, and the combined DTH response induration, was significantly related to the clinical stage of HIV disease. Median total lymphocyte counts were significantly lower in HIV-seropositive patients than in HIV-seronegative patients (1,130 vs. 1,680 lymphocytes x 10(6)/L). Total lymphocyte counts decreased with increasing severity of HIV disease. In multivariable analysis, the number of positive antigens in DTH testing and lymphopenia significantly predicted HIV infection. The findings suggest that DTH testing and total lymphocyte counts may be useful, inexpensive tests of immune function in African patients with HIV disease.