Assess the serologic response towards microbial antigens in Crohn's disease patients, their unaffected first-degree relatives and healthy controls.
This retrospective study included 60 Crohn's disease patients, 86 unaffected first-degree relatives and 100 healthy controls. Their sera were tested for anti-chitobioside, anti-laminaribioside, anti-mannobioside, anti-Saccharomyces cerevisiae and anti-outer membrane porin C of Escherichia coli.
The prevalence of anti-chitobioside and anti-laminaribioside was higher in Crohn's disease patients and their first-degree relatives than in healthy controls (51.67 % , 61.63 % and 8 % , respectively, for anti-chitobioside and 76.17 % , 88.37 % and 23.00 % for anti-laminaribioside; p < 0.0001).
The cumulative semiquantitative immune response against all the tested antibodies was higher in unaffected relatives than in healthy controls (p < 0.001).
The quantitative analysis revealed that serum levels of anti-chitobioside, anti-laminaribioside and anti-mannobioside were similar in first-degree relatives and Crohn's disease patients and higher than healthy controls (p < 0.001).
Both qualitative and quantitative analysis revealed that unaffected first-degree relatives have increased antibody response to microbial antigens. This impaired immunological response towards enteric microorganisms may result from a genetic predisposition.