Role of endoscopic ultrasonography in predicting the response to cyclosporin A in ulcerative colitis refractory to steroids

Background and aims: Although cyclosporin A has been reported to be effective in the treatment of severe ulcerative colitis, factors predicting its therapeutic efficacy remain unclear. Technical progress in endoscopic ultrasonography has improved visualisation of the structure of the colon wall. Here, to assess the value of endoscopic ultrasonography in predicting the response to cyclosporin A treatment, we evaluated the therapeutic effect of cyclosporin A by determining the pre- and post-cyclosporin A thickness of the mucosal layer in the rectum using endoscopic ultrasonography with an ultrasonic catheter probe. Patients and methods: Fifteen ulcerative colitis patients who did not respond to high-doses of corticosteroids were treated with cyclosporin A by continuous intravenous infusion at 4 mg/kg/day for 20 days. Before and 20 days after cyclosporin A therapy, clinical disease activity was assessed using clinical activity index scores. Colonoscopy and endoscopic ultrasonography were undertaken before and 20 days after cyclosporin A therapy. Results: Following treatment with cyclosporin A, nine patients showed a decrease in clinical activity index score by six points or more and were defined as responders, while the other six were defined as non-responders. Endoscopic ultrasonography measurement using an ultrasonic catheter probe showed that thickness of the rectal mucosal layer before cyclosporin A was significantly greater in responders than in non-responders (p < 0.05). Further, thickness after cyclosporin A was statistically decreased (p < 0.01) in the responders but not in the non-responders. Conclusions: The ultrasonic catheter probe may represent a useful means of predicting and evaluating the efficacy of cyclosporin A treatment in severely ill ulcerative colitis patients.