Diagnosis of Microscpic Colitis by Chromogranin A

Abstract

SUMMARY T he lack of reliable biomarkers and overlap of IBS symptoms with other organic conditions make most physicians to consider IBS as a “diagnosis of exclusion”. Physicians are particularly concerned about missing cancer colon, inflammatory bowel diseases (IBDs) & Microscopic colitis in patients with IBS symptoms, especially those that include a diarrheal component. So, patients with IBS symptoms especially diarrheal IBS should undergo colonoscopy and multiple colonic biopsies even with normal colonic mucosa. Our study was designed in Ain Shams university hospitals and October 6 university hospital among patients who sought medical advice in the GIT clinic for their gastrointestinal symptoms in the period between February 2016 to December 2016. A total of 100 patients were diagnosed as IBS-D according to the Rome IV criteria. Extensive history taking, clinical examination, laboratory investigations, abdominal ultrasonography, and total colonoscopy were done aiming to identify patients with irritable bowel syndrome and excluding any other possible cause of the diarrhea.  By history taking & physical examination, 20 patients were excluded.  After laboratory examination, 15 patients were re-excluded:  Abdominal ultrasonography, excluded 3 patients.  Undergoing upper GIT endoscopy with dudenal biopsies & aspirate excluded 2 Patients.  3 patients refused to do colonoscopy.  7 patients had gross endoscopic mucosal abnormalities in the colon and excluded from the study. Finally, a total of 50 Patients with normal mucosa were biopsied and upon histopathological examination, the patients were categorized into four groups (Microscopic colitis, chronic nonspecific colitis, Eosinophilic colitis & Ulcerative colitis). Their data were collected and statistically analyzed. The results were as follows:  Upon pathological diagnosis, 74% of patients have chronic nonspecific colitis. 10% have Microscopic colitis.6% have Eosinophilic colitis. 2% have Melanosis coli. 8% of the studies patients have UC.  There is no statistically significant difference between the four groups as regards (Age, Gender. Smoking status & mucosal bacterial invasion).  There is statistically significant difference between patients groups as drug consumption and presence concomitant diseases.  There is no statistically significant difference between the two subgroups of MC (LC & CC) as regards their ages, sex, duration of diarrhea, colonic mucosal bacteria, smoking, possible offending drugs & associated diseases.  Chromogranin A is a common marker for endocrine cells, and the present finding suggests that colonic hormones and neuro endocrine hypothesis are involved in the pathophysiology of MC.