SERUM BETA(2)-MICROGLOBULIN AND PREDICTION OF PROGRESSION TO AIDS IN HIV-INFECTED INJECTION-DRUG USERS

Several immunological and serological variables have become establishe d in recent studies as valuable markers to identify human immunodefici ency virus (HIV)-positive individuals at the highest risk for rapid di sease progression. These studies have been performed mainly in cohorts of homosexual men. In this study, we assessed the usefulness of CD4 l ymphocyte count, serum beta(2)-microglobulin concentration, and the pr esence of p24 antigen as predictors of AIDS in a cohort of 130 HIV-pos itive injection drug users (IDUs) followed-up for 1 to 67 months. Prog ression to AIDS was most strongly associated with reduced absolute num bers of CD4(+) lymphocytes at baseline, but increases in beta(2)-micro globulin levels at baseline were an independent predictor of outcome. After stratification by baseline CD4 count, beta(2)-microglobulin conc entration added significant prognostic information to CD4 count among IDUs with > 500/mm(3) CD4 cells (Breslow statistic value, 5.84, p = 0. 01). Thus among seropositive IDUs with normal CD4 counts, increases in beta(2)-microglobulin may be used as an early marker of individuals w ith higher risk of progression to AIDS, who may benefit from more inte nsive laboratory monitoring or clinical management.