Serum zymogen glycoprotein 2 antibodies (anti-GP2) in patients with inflammatory bowel disease

Abstract

Purpose of the study: The aim of the study is to examine the incidence and significance of serum antibodies against zymogen glycoprotein 2 (anti-GP2) in patients with inflammatory bowel disease (IBD).

Methods: Eighty-one patients with IBD were examined, 66 patients with Crohn's disease (CD) and 15 with ulcerative colitis (UC); there was also a control group of 20 patients with untreated coeliac disease and 50 healthy blood donors. All examined patients with IBD were treated with infliximab. Analyses of anti-GP2 IgG/lgA were performed in samples from week 0 (W0) and week 10 (W10) of the treatment.

Results: Anti-GP2 in at least one isotype were found in 52% of patients with CD, but only in 13% of patients with UC (p = 0.007). In both control groups, the incidence of anti-GP2 was minimal. Compared to UC patients, individuals with CD achieved significantly higher concentrations of anti-GP2 (p = 0.001 for anti-GP2 IgG at W0 and p < 0.001 for anti-GP2 IgA at W0). No significant changes in concentrations of auto-antibodies were observed during 10 weeks of the biological treatment. No evidence of anti-GP2 IgG/lgA association with gender, age, location or type of IBD, or with the activity of the disease was proven. The only significant correlation was found in anti-GP2 IgA with CD damage when stricturing and fistulizing form was related to more frequent incidence and higher anti-GP2 IgA titres.

Conclusions: Anti-GP2 occure in approximately half of patients with CD. The incidence of anti-GP2 does not correlate with CD location, form or type of the alimentary tract damage; it is not related to the disease activity and concentrations of autoantibody concentrations do not change significantly during the IBD biological treatment.