[Cyclosporin A in acute Crohn disease: initial findings].

The pathogenesis of Crohn's disease is unknown, but immunologic mechanisms appear to play at least a partial role. Prompted by favourable experience with cyclosporin A in autoimmune diseases, the authors used it in steroid resistant acute Crohn's disease and started a pilot study comparing cyclosporin A with prednisone. Initial experience shows that cyclosporin A is effective in at least some patients with acute Crohn's disease. Side effects have thus far been minimal. However, oral dosage of the drug is difficult and regular determinations of the trough blood concentration are indispensable. A trough blood concentration of 200 ng/ml appears to be necessary to obtain full therapeutic activity. The lower antipyretic effect of cyclosporin A compared to prednisone may initially mask a favourable therapeutic effect. The effectiveness of cyclosporin A compared with prednisone cannot yet be evaluated.