Importance of Eosinophilic Infiltration of the Colonic Mucosa in Ulcerative Colitis Patients who are Refractory to Maintenance Therapy

Abstract

Eosinophilic infiltration is sometimes observed histologically in ulcerative colitis (UC), but the effect of the degree of infiltration on the treatment course for UC is not completely studied. We investigated whether short-term steroid administration in UC patients refractory to maintenance therapy, with high eosinophilic infiltration in the colonic mucosa, contributed to clinical and endoscopic improvement. Ten patients with endoscopically active and pathologically high eosinophilic infiltration, based on pathological examination using endoscopic biopsy, were examined for clinical background when starting steroid treatment; clinical and endoscopic improvement before and after steroid use were assessed prospectively. The average initial steroid dosage and duration of use were 21.0 mg and 102.7 days, respectively. The mean values before and after steroid use of clinical activity index, Mayo endoscopic subscore, and UC endoscopic index of severity were 2.4 and 1.0, 1.8 and 0.7, and 3.9 and 1.1, respectively. All these scores improved significantly after steroid use (P=0.04, P<0.01, P<0.01, respectively). Steroids were discontinued in all patients; no patients required steroid re-administration. There may be cases of UC with eosinophilic infiltration into the colonic mucosa and resistant to maintenance treatment, suggesting that short-term steroid administration may contribute to clinical and endoscopic improvements.