LACK OF DIRECT CORRELATION BETWEEN CD4 T-LYMPHOCYTE COUNTS AND INDURATION SIZES OF THE TUBERCULIN SKIN-TEST IN HUMAN-IMMUNODEFICIENCY-VIRUSTYPE-1 SEROPOSITIVE PATIENTS

SETTING: The study was conducted in Bobo-Dioulasso, Burkina Faso, wher e Mycobacterium tuberculosis infection and human immunodeficiency viru s type 1 (HIV-1) infection are prevalent. OBJECTIVE: To identify propo rtions of representative (test) populations who are reactive to the tu berculin skin test, and to study the relationship between CD4 T-lympho cyte counts and the induration size of the tuberculin skin test in the se groups. DESIGN: A group of 435 healthy students was tuberculin skin tested in order to evaluate the intensity of skin testing in a 'norma l' population. The study group consisted of 195 subjects with or witho ut tuberculosis, and with or without HIV-1 infection, who received a t uberculin skin test and a CD4 T lymphocyte count on the same day. RESU LTS: In total, 90% of the control (nontuberculous, HIV negative) subje cts, 32% of the HIV-1 seropositive subjects, 76.5% of the tuberculous patients and 57% of the tuberculous HIV-1 seropositive patients were t uberculin positive. There was no direct correlation between the indura tion size of reactions to the tuberculin skin test and CD4 T-lymphocyt e count in these study groups using linear regression analysis. CONCLU SION: In vivo skin testing using tuberculin yields clinically signific ant information on the degree of immunodeficiency which is different f rom that of CD4 T-lymphocyte counts. The tuberculin skin test should t herefore be used as an independent marker of the weakened immunologica l status of HIV-1 seropositive subjects.