Defective generation of tetanus-specific antibody-producing B cells after in vivo immunization of Crohn's disease and ulcerative colitis patients.

In vivo booster immunization with tetanus toxoid normally results in the temporal development of circulating populations of B cells that secrete antibody after in vitro culture. In assessing the humoral immunoregulatory status in patients with inflammatory bowel disease, we found that the antibody production by the B cells that spontaneously secrete tetanus-specific immunoglobulin G in vitro, and which occur in the circulation 7 days postimmunization, was highly variable and below normal in the majority of Crohn's disease and ulcerative colitis patients. The decreased in vitro antibody responses correlated with the lack of an increase in the serum antitetanus immunoglobulin G titers, but did not correlate with disease activity, location, or steroid therapy. The majority of patients who did not produce an immunoglobulin G-antitetanus toxoid antibody response similarly failed to produce an immunoglobulin G-antidiphtheria antibody response after immunization. Lymphocytes from the patients who failed to produce normal levels of antitetanus toxoid antibody did, however, proliferate normally when stimulated by tetanus toxoid in vitro. These results suggest there are in vivo humoral immune defects in inflammatory bowel disease.