Paul-Bunnell antigen in malignancies and rheumatoid arthritis.

By means of agglutination inhibition test, Paul-Bunnell (P-B) antigen was demonstrated in sera of patients with cancer (5%), lymphomas or leukemias (12.5%) and rheumatoid arthritis (RA) (1.4%) as well as in synovial fluids from RA patients (27%). In contrast, none of 124 normal human sera gave positive results. P-B antigen was also demonstrated in 3 of 12 perchloric acid extracts of cancer tissues and 2 of 11 saline extracts obtained at 100 degrees C from spleens of lymphoma-leukemia patients. Extracts of apparently normal tissues from 16 individuals gave negative results.