Cold-reactive lymphocytotoxins in Crohn's disease and ulcerative colitis. I. Incidence and characterization.

The incidence of cold-reactive lymphocytotoxins in the serum of patients with Crohn's disease or ulcerative colitis has been investigated. Twenty-seven percent of patients with Crohn's disease and twenty-two percent of those with ulcerative colitis had circulating lymphocytotoxins. This is significantly higher than the 4% found in a normal control population. The presence of lymphocytotoxins did not correlate with age or sex of the subjects studied nor with clinical parameters. As in previous studies, the lymphocytotoxin is an antibody of IgM class, is optimally effective at 15 degrees C in the presence of complement and reacts with both T and B lymphocytes. The lymphocytes from patients with active Crohn's disease or ulcerative colitis are poorly susceptible to lysis by lymphocytotoxins but lymphocytes from patients in remission are as susceptible as normal lymphocytes. This implies that the lymphocyte surface is altered during active disease although the pathogenetic significance of this is unclear.