Tissue content of mucins in the colonic mucosa with and without fecal stream: a clinical study.

BACKGROUND

Alterations in mucin expression in the intestinal mucosa are among the main histological findings in inflammatory colonic diseases. No previous study has quantified the tissue expression of neutral and acidic mucins, including sulfomucins and sialomucins, in patients with diversion colitis.

AIMS: To quantify the tissue content of neutral and acidic mucins (sulfomucins and sialomucins) in colonic mucosa with and without intestinal transit.

METHODS

Forty patients undergoing elective colonoscopy at the Hospital de Clínicas - Unicamp were included. Group 1 comprised 20 patients with an ileostomy or colostomy for more than two months. Group 2 (control) included 20 patients without any type of ostomy. Patients with inflammatory bowel disease or previous pelvic radiotherapy were excluded. Three mucosal biopsies were obtained from each patient during colonoscopy. Neutral and acidic mucins were assessed using Periodic Acid-Schiff and Alcian Blue staining, respectively. Acidic mucin subtypes (sulfomucins and sialomucins) were identified using Alcian Blue-high iron diamine. Tissue content was quantified by computer-assisted image analysis. Statistical analysis compared mucin levels between segments with and without fecal transit, with significance set at p<0.05.

RESULTS

Colonic segments without fecal transit showed a significant reduction in the tissue content of all mucin subtypes.

CONCLUSIONS

All mucin subtypes (neutral, acidic, sulfomucins, and sialomucins) were significantly reduced in colonic segments deprived of fecal stream.