Serum ANCA versus endoscopic histopathological findings in diagnosis of patients with ulcerative colitis

ABSTRACT

Ulcerative colitis [UC] is defined as continuous idiopathic inflammation of colonic mucosa that begins in the rectal area and may extend through the entire large bowel. The diagnosis of UC depends on clinical picture, stool analysis, endoscopie appearance and histopathological assessment of endoscopic biopsy. The aim of this work was to assess the value of pANCA in the diagnosis of UC as a non-invasive diagnostic tool versus the endoscopie and histoapathological examinations This study included seventy patients which were grouped into three groups Group [I] Included 20 patients with UC [13 males and 7 females with mean age of 28, 7 +/- 9.83 years], Group[II] Included 20 patients with nonspecific colitis [8 males and 12 females with mean age of 40.4 +/- 10.8 years] and Group[III] that Included 30 subjects with normal lower endoscopy as control group [18 males and 12 females with mean of age 27l +/- 6.llyears]. All patients were subjected to thorough history taking. full clinical examination, urine analysis. stool examination and culture, ESR, CRP, complete blood picture. serum iron, liver function tests, renal function tests, abdominal plain X-ray, abdominal ultrasound, lower endoscopic and histopathological examinations, pANCA detection by ELISA and confirmed by IF technique Perinuclear anti nuetrophil cytoplasmic antibodies [pANCA] detected by ELISA were positive in 75% of UC patients and in 10% of non specific colitis patients while all control group subjects were negative. pANCA detected by ELISA had 75% sensitivity. 95% specificity, 88.2°/a positive predictive value and 90.5% negative predictive value for ulcerative colitis patients pANCA detected by IF technique were positive in 85% of UC patients and 25% of non specific colitis patients while none of control group was positive. pANCA by I had 85% sensitivity, 90% specificity. 77.3% positive predictive value and 93.7% negative predictive value for ulcerative colitis patients Conclusion pANCA is a beneficial senomarker detected in 75%-85% of patients with ulcerative colitis. pANCA detected by ELISA technique has high specificity and relatively low sensitivity for ulcerative colitis. Combined ELISA and IF technique for detection of pANCA may add higher sensitivity for pANCA as a seromaker for diagnosis of ulcerative colitis and can be used as a non invasive tool for diagnosis of ulcerative colitis especially when lower cndoscopy is contraindieated