Course of Crohn's disease after allogeneic marrow transplantation.

BACKGROUND & AIMS Remission of several autoimmune diseases has been described after allogeneic marrow transplantation. The aim of this study was to determine if the natural history of Crohn's disease was altered by hematopoietic cell transplants from healthy allogeneic donors. METHODS Between 1982 and 1992, 6 patients with Crohn's disease and leukemia underwent allogeneic marrow transplantation and were followed up clinically. RESULTS Five patients had active Crohn's disease before transplantation, and 3 had clinical evidence of sclerosing cholangitis. Four marrow donors were HLA-identical siblings, 1 related donor was mismatched at the DR locus, and 1 unrelated donor was HLA-matched. One patient died of septicemia 97 days after transplantation; 5 patients were observed for 4.5, 5.8, 8.4, 9.9, and 15.3 years after transplantation. Four of 5 patients evaluated had no signs or symptoms of Crohn's disease after transplantation. One patient with mixed donor-host hematopoietic chimerism had a relapse of Crohn's disease 1.5 years after transplantation. CONCLUSIONS Four of 5 patients followed up for 4.5 to 15.3 years after allogeneic hematopoietic cell transplantation remained free of Crohn's disease. These observations suggest that host immune dysregulation plays a role in the perpetuation of Crohn's disease that can be corrected by allogeneic hematopoietic cell transplantation.