PANCREATIC AUTOANTIBODIES IN CROHNS-DISEASE - A FAMILY STUDY

Background-Pancreatic antibodies occur in about one third of patients with Crohn's disease. Aims-To evaluate the relevance of pancreatic ant ibodies as a genetic marker in patients with Crohn's disease and their first degree family members and spouses. To characterise further panc reatic antibodies by assessment of IgG subclasses. Methods-Six hundred and fifty serum samples were tested for pancreatic antibodies by immu nofluorescence on sections of human pancreas. Incidence of pancreatic antibodies and their subtypes were studied on 212 serum samples from p atients with Crohn's disease. In the familial study, 72 patients with Crohn's disease and 196 first degree family members and 26 patients wi th ulcerative colitis and 90 first degree family members were included . Ten healthy families sewed as controls. Results-Pancreatic antibodie s were found in 58 (27%) of the patients with Crohn's disease and in n one of the controls. Thirty patients had pancreatic antibodies of subt ype I characterised by a drop-like fluorescence in the pancreatic acin i, 28 patients had subtype II with a fine speckled staining in the aci nar cells. Pancreatic antibodies of subtype I were both IgG1 and IgG2 antibodies by contrast with subtype II which were mainly of IgG1 subcl ass. Only five of 196 first degree relatives of patients with Crohn's disease had pancreatic antibodies. Four of these people had anamnestic data compatible with inflammatory bowel disease. Further investigatio ns showed Crohn's disease in two of these people. In families with mor e than one member positive for pancreatic antibodies, pancreatic antib odies were of the same subtype in all cases. Conclusions-Pancreatic an tibodies are a specific marker for Crohn's disease. Two subgroups of p ancreatic antibodies can be distinguished by their pattern and immunog lobulin subclasses. Pancreatic antibodies rarely occur in family membe rs of patients with Crohn's disease. These family members may also hav e Crohn's disease.