THE 90K TUMOR-ASSOCIATED ANTIGEN AND CLINICAL PROGRESSION IN HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

We investigated the possibility that a secreted glycoprotein of simila r to 90,000 daltons, termed 90K and identified as a member of the prot ein superfamily characterized by the scavenger receptor cysteine-rich (SRCR) domain, might have value as a predictor of progression to acqui red immunodeficiency syndrome (AIDS) in subjects infected with the hum an immunodeficiency virus (HIV). Among 488 HIV-seropositive intravenou s drug users with a median follow-up of 32.5 months, high levels of se rum 90K at baseline proved to be a significant predictor of faster pro gression to AIDS, either as a continuous variable (log 90K; p < 0.0001 ) or as a dichotomous variable with an optimized cutoff point of 30 U/ ml (p < 0.00001). Analysis of 90K in relation to known prognostic fact ors found an association with CD4 count, beta(2)-microglobulin, and p2 4 antigen but none with neopterin. In multivariate analysis, the basel ine 90K level was an independent predictor of AIDS. As compared with s ubjects with low levels of 90K, the relative risk of developing AIDS w as 3.5 (95% CI 1.9-6.5) among those with high levels of 90K, The predi ctive value of 90K was maintained after stratification by baseline CD4 count: among subjects with greater than or equal to 500 x 10(6)/L CD4 cells, the proportion in whom AIDS developed was 10.5% for those with 90K levels less than or equal to 30 U/ml as compared with 20% for tho se with 90K above the cutoff point (p = 0.006), Serum 90K is an indepe ndent predictor of the risk for progression to AIDS in HIV-infected su bjects, including those whose CD4 counts have not fallen.