Do high serum levels of anti-Saccharomyces cerevisiae antibodies result from a leakiness of the gut barrier in Crohn's disease?

OBJECTIVES

To examine the relationship between serum levels of anti-Saccharomyces cerevisiae antibodies (ASCAs) and intestinal permeability at a given time (hypothesis 1) and the probability of increased ASCA serum levels with increased intestinal permeability (hypothesis 2) in patients with Crohn's disease.

METHODS

Each hypothesis was tested retrospectively with its own study population: group A for hypothesis 1 and group B for hypothesis 2. Intestinal permeability was measured by lactulose/mannitol test and ASCAs were quantified by using ELISA. Patients received either no treatment or 5-aminosalicylates. The lactulose/mannitol test and sampling of sera for ASCA assessment had to be performed within 1 month in group A. In group B the highest intestinal permeability value obtained from among at least three measurements made during different stages of disease activity was chosen for evaluation.

RESULTS

Both study populations consisted of 140 patients with Crohn's disease. Elevated IgG ASCAs were detected in 64% (90/140) in group A compared with 65% (91/140) in group B. In group A, 64% (90/140) and in group B 66% (92/140) were IgA ASCA positive. Correlation analysis showed a tendency for a positive relationship between IgG ASCAs and intestinal permeability in group A (tau = 0.16, P = 0.07) and in group B (tau = 0.16, P = 0.06). A positive trend was seen for the combination of high intestinal permeability and high IgG ASCAs in group B (chi-squared test, P = 0.07).

CONCLUSION

Elevated serum levels of anti-S. cerevisiae antibodies do not seem to result primarily from a defect of the gut barrier. This observation points to an intrinsic pathomechanism in the development of increased ASCA serum levels.