ASCA and ANCA among Bedouin Arabs with inflammatory bowel disease, the frequency and phenotype correlation

Background: Serological markers used for diagnostic purposes and disease stratification in inflammatory bowel disease. We aimed to investigate the frequency of ASCA and ANCA among Arab Bedouin IBD patients and its relationship to disease phenotype and course. Methods: From cohort of 68, 25 Crohn's disease (CD) and 25 Ulcerative colitis (UC) patients were recruited (72%). ASCA IgG was determined by ELISA assay. Immunofluorescence analysis of ANCA was performed. Results: The IgG ASCA was detected in 13 (52%) of the CD patients and in three (12%) UC patients. The prevalence of ANCA among UC patients was positive with 76%, sub-grouped, atypical ANCA in 9 patients (36%), pANCA in six patients (24%) and cANCA in 4 patients (16%). The detection of ASCA among CD patients was found not to be a reliable predictor of young age at diagnosis, gender, ileal involvement, anti-TNF treatment or surgery. UC patients with positive ANCA were younger, mean age 40.2 ± 11.9 compared with 57.3 ± 21.2 (p = 0.03), and diagnosed at a younger age, 29.2 ± 11.8 compared with 43.5 ± 15.3 (p = 0.05). Conclusion: The frequency of ASCA among Bedouin CD patients and ANCA among UC patients was high, however ASCA was not found to have a predictive value for disease phenotype or course. Positive ANCA in UC patients was predictive for younger age and age at diagnosis.