Transient acquired blood group B antigen associated with diverticular bowel disease

Transient acquired B red cell antigen was found in a patient with inflammatory bowel disease. Removal of the affected portion of the bowel was associated with disappearance of the B antigen. This phenomenon has usually been recorded in association with neoplasms of the bowel, but appears to be a marker for the release of bacterial enzymes into the systemic circulation associated with breakdown of the normal bowel barrier to such materials.