OBJECTIVE: The aim of this study was to compare the treatment efficacies of subcutaneous interferon-alpha-2A (IFN-alpha-2A) injections versus prednisolone enemas in active left-sided ulcerative colitis in an open-labeled, randomized study.

METHODS: Sixteen ulcerative colitis patients received IFN-alpha-2A subcutaneously (dosage: first wk, 9 MIU three times weekly [t.i.w.]; second wk, 6 MIU t.i.w.; wk 3-12, 3 MIU t.i.w.), and 16 received prednisolone enemas for 30 days (100 ml once daily, 0.25 mg of prednisolone/ml). The Powell-Tuck Index, Inflammatory Bowel Disease Questionnaire (IBDQ) score, and rectal histological activities were assessed before and after treatment. Thirteen patients in the IFN-alpha-2A group and all 16 in the prednisolone enema group completed the treatment.

RESULTS: IFN-alpha-2A treatment showed significant improvements in the Powell-Tuck Index (p = 0.0002), IBDQ score (p = 0.002), and rectal histological activity scores (p = 0.02). In the enema group, significant improvements were found in the Powell-Tuck Index (p = 0.0009), whereas no significant improvements were detected in the IBDQ scores (p = 0.055) or rectal histological scores (p = 0.052). There were no differences between scores of the two groups either before or after treatment. Only moderate side effects from the IFN-alpha-2A treatment were seen during the first 2-4 wk of treatment.

CONCLUSION: IFN-alpha-2A treatment resulted in significant depression of the disease activity as reflected by the Powell-Tuck Index, IBDQ score, and histological disease activity scoring. The preliminary trial thus suggests that IFN-alpha-2A may be effective in the treatment of active left-sided ulcerative colitis. Larger, randomized trials are, however, warranted to confirm this finding, owing to possible type II errors in group comparisons.