ELEVATED SERUM LEVELS OF A 90,000-DALTONS TUMOR-ASSOCIATED ANTIGEN INCANCER AND IN INFECTION BY HUMAN-IMMUNODEFICIENCY-VIRUS (HIV)

Levels of a 90,000 daltons monoclonal antibody-defined tumor-associate d antigen, termed 90K, were measured in the serum from 649 patients wi th various types of cancer and 1215 patients infected by the human imm unodeficiency virus (HIV). Significantly increased 90K serum levels (1 2.1+/-0.5 U/ml) were found in cancer patients with respect to healthy controls (5.7+/-0.3 U/ml), with the highest levels in neoplasms of the breast, lung and gastrointestinal tract. In 355 patients with breast cancer, the elevation of serum 90K levels was more pronounced at advan ced stages of disease. Mean levels of 90K for 1215 HIV-infected subjec ts (21.2+/-0.8 U/ml) were significantly higher than controls and cance r patients, and the levels progressively increased with disease worsen ing from asymptomatic infection to full blown AIDS. These data suggest that 90K is not merely a tumor-associated antigen and lead us to post ulate it to be a signalling molecule whose production might be related to the immune deficit caused by pathogenetic events such as neoplasti c progression and virus infection.