AUTOANTIBODY PREVALENCE AND ASSOCIATION IN INFLAMMATORY BOWEL-DISEASE

Objective: To study the prevalence and correlation of the following an tibodies with disease activity: antineutrophil cytoplasmic antibodies (ANCA), anti-endothelial cell antibodies (AECA) and anti-epithelial ce ll (anti-EPI) antibodies. Patients and methods: Sera from the followin g patients were tested: 41 patients with ulcerative colitis, 30 patien ts with ulcerative colitis following restorative proctocolectomy (RPC) , 30 patients with Crohn's disease, 10 disease controls, and 34 health y controls. Results: ANCA were found in 65 patients (64%) [31 with ulc erative colitis (76%); 21 with ulcerative colitis following RPC (70%); 13 with Crohn's disease (43%)]. AECA were found in 33 patients (33%) [15 with ulcerative colitis (37%); 12 with ulcerative colitis followin g RPC (40%); six with Crohn's disease (20%)] and anti-EPI antibodies i n 20 patients (20%) [six with ulcerative colitis (15%); six with ulcer ative colitis following RPC (20%); eight with Crohn's disease (27%)]. A strong association between ANCA and both AECA (P= 0.0001) and anti-E PI antibodies (P= 0.003) was noted. Significant cross-reactivity was n oted between ANCA and anti-EPI antibodies (P=0.0001), but not between ANCA and AECA (P=0.09) following removal of ANCA from the sera (adsorp tion) by isolated neutrophils fixed on microtitre plates. The prevalen ce of these autoantibodies did not correlate with either disease activ ity or treatment. Conclusion: All antibodies persisted despite total c olectomy, indicating that these antibodies do not merely reflect colon ic inflammation. The cross-reactivity of ANCA with anti-EPI antibodies could be an important factor which may help to explain the high preva lence of ANCA in ulcerative colitis.