title: Decreased mucosal IgA levels in ileum of patients with chronic ulcerative colitis.
abstract: Patients with chronic ulcerative colitis (CUC) are known to have decreased spontaneous IgA secretion by colonic mononuclear cells. The aim of this study was to determine whether a similar alteration exists in the apparently healthy ileum of patients with CUC. The concentration of IgA was measured in the supernatant from homogenized mucosal ileal biopsies using a sandwich-type ELISA. The concentration of IgA was significantly (P = 0.025) decreased in the ileum of patients with CUC (N = 24) in comparison to normal ileum (N = 10). The number of mucosal IgA-containing mononuclear cells (MNC) was also determined using an avidin-biotin-immunoperoxidase technique on paraffin-embedded ileal sections. Although reduced, the number of positive cells and their distribution was not significantly different in the ileum of patients with CUC (N = 20) when compared to normal ileum (N = 10). We suggest that decreased mucosal IgA levels are a panintestinal condition in CUC and that this is a primary alteration rather than a secondary response to the inflammatory process. Considering the role of IgA, we propose that decreased mucosal IgA levels in CUC may predispose to the disease by a reduction of the immune-mediated exclusion mechanism and/or by an impairment of the down-regulation of the inflammatory response.
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pennsylvania, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cicalese
authors.forename: R H
authors.initials: RH
authors.lastname: Duerr
authors.forename: M A
authors.initials: MA
authors.lastname: Nalesnik
authors.forename: P F
authors.initials: PF
authors.lastname: Heeckt
authors.forename: K K
authors.initials: KK
authors.lastname: Lee
authors.forename: W H
authors.initials: WH
authors.lastname: Schraut
mesh_terms: D002908:Chronic Disease; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007082:Ileum / Q000276:immunology*; D007070:Immunoglobulin A / Q000032:analysis*; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A