[Serum immunoglobulin concentrations in Crohn's disease. Clinical relevance and comparison with lipid-A-antibody titers (author's transl)].

The results of previously published studies on serum immunoglobulin concentrations in patients with Crohn's disease are controversial. Therefore a long term study of serum immunoglobulin concentrations comparing 31 patients with Crohn's disease was carried out. The serum IgM concentrations of patients with active disease was significantly lower than the serum IgM concentration in patients with inactive disease. 7/25 patients who were all treated with steroids had an elevated serum IgE concentrations. It could not be demonstrated that serum immunoglobulin concentrations are influenced by steroids, by bowel resection or by the activity of the disease. As no characteristic change of serum immunoglobulin concentration in patients with Crohn's disease could be found the determination of serum immunoglobulins seems to be of no clinical value. Furthermore a possible connection between serum immunoglobulin concentrations and antibody titers against the lipid A component of endotoxins was investigated: Serum IgM concentrations were significantly higher in patients with elevated lipid-A-antibody titers than in patients with normal lipid-A-antibody titers. Thus indicates a specific antibody formation to endotoxins and lipid A, respectively.