Crohn's disease, serum immunodepressive factors and circulating immune complexes.

The presence of serum immunodepressive factors (SIDF), able to inhibit E-rosette formation of normal donor lymphocytes and the presence of circulating immune complexes (CIC) was studied in sera from 45 patients with Crohn's disease. Significantly elevated levels of both SIDF and CIC were detected in the majority of the examined cases. The parameters seem to correlate well with the disease activity. The effect of SIDF on E-rosette formation could be at least partially neutralized by simultaneous incubation with levamisole.