386 Hypersensitivity Reactions to Interferon Based Treatment for Hepatitis C: A Single Center 20-Year Experience

BACKGROUND: BA Interferon (IFN)-based therapy for chronic hepatitis C (CHC) is associated with adverse hypersensitivity reactions (HRs). However, data on HRs to IFN in every-day clinical practice are lacking. We conducted a retrospective study to identify the incidence, management and outcome of such reactions. METHODS: A review of the electronic files of all CHC patients followed in our tertiary referral center from January 1990 to November 2010 was conducted to identify patients submitted to IFN-based treatment and HRs to such treatment. RESULTS: During the study period, 832 CHC patients were identified, 545 (65.5%) of whom received IFN-based treatment. Overall, 221 (40.5%) patients received at least one treatment cycle with IFN-a ± ribavirin (RBV), 170 (31.2%) patients received at least one treatment cycle with pegylated (PEG)-IFN a2a + RBV and 189 (34.7%) patients received at least one treatment cycle with PEG-IFN a2b + RBV. Fifty-five treatment cycles were complicated by HRs in 54 patients (female 20, median age 39 years, range 22–65 years). Presenting symptoms of HRs were: skin rash in 46 patients (pruritic in 20), generalized pruritus in 7 patients and aphthous mucosal ulcers in 2 patients. HRs occurred in 9 patients treated with IFN-a (4.1%), 23 patients treated with PEG-IFN a2a (13.5%) and 23 patients treated with PEG-IFN a2b (12.1%) (P = 0.002). Management of HRs included no intervention in 18 (32.7%) cases, topical treatment in 10 (18.2%) cases, antihistamine administration in 15 (27.3%) cases, temporary cessation of treatment or dose reduction in 3 (5.5%) cases, switch from PEG-IFN to IFN-a in 4 (7.3%) cases and immediate termination of treatment in 5 (9.1%) cases. The outcome was complete remission of the HR in 33 (60%) cases, remission sufficient to allow continuation of treatment in 13 (23.6%) cases and treatment termination in 8 (14.5%) cases, while one (1.8%) patient was lost to follow-up after the HR. Overall, 2 (0.9%) patients discontinued IFN-a, 3 (1.8%) PEG-IFN a2a and 3 (1.6%) PEG-IFN a2b due to HRs (P = 0.737). CONCLUSIONS: Hypersensitivity reactions to IFN-based and especially to PEG-IFN based treatment regimens are occasionally encountered in CHC patients and may rarely lead to treatment termination.