Humoral Immune Response And Luminal Microorganisms In Patients With Indeterminate Colitis

Background: Microorganisms that directly interact with the intestinal mucosa are obscured by fecal flora. Some members of the endogenous faecal microflora have a clear detrimental role in most animal models of colitis and enteritis. This is strongly suspected to be the cause of indeterminate colitis (IC).Patients and methods: The study consisted of two groups : 75 patients groups with IC and control group consisted of 30 healthy volunteers. Sigmoidoscope and colonoscope examination were done for the patients group and biopsy were also taken from suspicious lesion for histopathological examination for confirming the diagnosis. Blood samples were collected from them and serum were collected for immunoglobulins (IgG, IgM and IgA) levels and complement (C3 and C4) level by single radial immune diffusion method (Biomaghrib-Tunis). Fecal and rectal swabs were taken from those groups, cultured on different bacteriological media, and isolated using different bacteriological methods for enteric bacteria isolation according to type of bacteria. Results: Male more than female are affected . About 53.3 % had bleeding per rectum. Most of their diseased location was in rectum then sigmoid and ascending colon. Bacteriological results showed a significant decrease in the existence of Bacteroids fragilis (anaerobic bacteria) in patients group compared with control. Studying humoral immune response demonstrated a significant higher level in IgG, IgA, C3 and C4 in patients group and significant decrease in IgM level in patients group.Conclusions: Reduction in anaerobic bacteria might be a cause in initiation colitis with stimulation of immunoglobulins production and complement activation to overcome this inflammation.