BACKGROUND Ulcerative colitis is an inflammatory disease of the colonic and rectal mucosa. Autoantibodies have been observed in ulcerative colitis which may have a role in the pathogenesis of the disease. Evidence also suggests that there is an hereditary predisposition towards the disease, although no individual genes have been identified.

AIMS This is a pilot study of immunoglobulin heavy chain genes (IgH) in ulcerative colitis to determine whether they have any particular genetic characteristics which may lead to a better understanding of the disease aetiology.

SUBJECTS Colonic or rectal tissue was obtained from five children with ulcerative colitis. Tissue was also obtained from five children with Crohn’s disease and five children who did not have inflammatory bowel disease as controls.

RESULTS An increase in the use of J_H6 and DXP′1, and a decrease in the use of J_H4, gene segments in immunoglobulin genes from lamina propria plasma cells, and from virgin IgD+ B cells, was found in patients with ulcerative colitis. These biases were not present in the control groups.

CONCLUSIONS There is a fundamental difference in the immunoglobulin genes from patients with ulcerative colitis. Whether this is caused by a difference in content of immunoglobulin gene segments in the germline or a difference in the recombination mechanism is not known.