Immunoglobulin G and albumin levels in whole gut lavage fluid provide an objective measure of pouch ileitis

Background: Gut protein loss is a characteristic of inflammatory bowel disease (IBD), and immunoglobulin (Ig) G, albumin and α₁-antitripsin concentrations in whole gut lavage fluid (WGLF) correlate with clinical disease activity. If inflammation in ileoanal pouches is similar to IBD, then measurement of protein-losing enteropathy by analysis of WGLF may provide an objective assessment of disease activity in pouches. Methods: Forty-two patients who had restorative proctocolectomy for ulcerative colitis underwent whole gut lavage with a polyethylene glycol-electrolyte solution. The first clear effluent was filtered, processed by the addition of protease inhibitors and stored at -70°C. IgG, albumin and α₁-antitrypsin were assayed in WGLF. The Pouchitis Disease Activity index (PDAI) was calculated after pouchoscopy and biopsy; the Moskowitz criteria for pouchitis were also applied. Results: There was a significant correlation of the pouchoscopy score and the PDAI with the concentration of WGLF IgG. All patients with 'pouchitis' according to the Moskowitz criteria had a WGLF IgG concentration greater than 10 μg/ml. The WGLF albumin level also showed a significant correlation with the PDAI, but α₁-antitripsin concentration did not. Conclusion: Analysis of WGLF for IgG and albumin may be useful in the assessment of disease activity in pouch inflammation.