Distinct elevation of levels of anti-Caenorhabditis elegans antibody in sera of patients with inflammatory bowel disease

Abstract

Dysregulation of immune responses to intestinal exogenous antigens contributes to the pathogenesis of inflammatory bowel disease, but the specific antigen responsible for the pathogenesis of inflammatory bowel disease is unknown. We measured serum antibody titers against Caenorhabditis elegans antigens. Immunoglobulin G (IgG) and IgG subclass anti-C. elegans antibodies in serum samples from 29 patients with ulcerative colitis, 30 patients with Crohn's disease, 7 patients with intestinal Behçet's disease, and 11 healthy controls were measured by enzyme-linked immunosorbent assay. Serum IgG and IgG2 antibody titers against C. elegans were significantly higher in patients with inflammatory bowel disease than in controls. Antibody levels were not affected by age, gender, disease activity, extent of disease, or small bowel involvement. The anti-C. elegans antibody titer was significantly lower in patients with Crohn's disease taking mesalazine or sulfasalazine than in patients not taking these drugs. The increased immune responses to C. elegans found in patients with inflammatory bowel disease reflect dysregulated immune responses to enteric antigens, which might play a role in the pathogenesis of inflammatory bowel disease.

FIG. 1.

IgG ACEA titers in healthy controls, patients with IBD, and patients with intestinal Behçet's disease. IgG ACEA titers were significantly higher in patients with IBD than in controls. Error bars indicate standard deviations.

FIG. 2.

IgG ACEA and 5-aminosalicylate derivatives. Patients with CD taking sulfasalazine or mesalazine had significantly lower IgG ACEA titers than patients with CD not taking these drugs. n.s., not significant. Error bars indicate standard deviations.

FIG. 3.

IgG subclass ACEA titers in healthy controls, patients with IBD, and patients with intestinal Behçet's disease. IgG2 ACEA titers were significantly higher in patients with IBD and intestinal Behçet's disease than in controls. IgG3 ACEA titers were significantly higher in patients with CD than in patients with UC. Error bars indicate standard deviations.

FIG. 4.

IgG subclass ACEA titers and disease involvement in patients with IBD. IgG3 ACEA titers were significantly higher for CD colitis than for total and left-sided UC and were significantly higher for CD ileitis than for left-sided UC. Error bars indicate standard deviations.

FIG. 5.

IgG subclass ACEA titers and 5-aminosalicylate derivatives. IgG2 ACEA titers were significantly lower in patients with CD taking either sulfasalazine or mesalazine than in patients not taking these drugs. Error bars indicate standard deviations.