Sarcoidosis associated with interferon-α therapy for chronic hepatitis C

Background/Aims: Pulmonary side effects of interferon-alpha therapy of chronic hepatitis C seem to be rare. So far, only two cases of sarcoidosis in association with interferon-alpha treatment of chronic hepatitis C have been described. Methods/Cases: We report on three patients who were treated with recombinant interferon-alpha 2a for chronic hepatitis C, two of them in combination with ribavirin. These patients developed pulmonary sarcoidosis 12, 20 and 21 weeks, respectively, after beginning interferon therapy, one patient with Lofgren's syndrome. In one patient sarcoidosis emerged only after discontinuation of interferon therapy because of treatment failure. Clinical symptoms of sarcoidosis in the three patients were suggestive of side effects of interferon-alpha. Interferon therapy was discontinued and spontaneous remission was observed in all three cases 5, 6, and 8 months, respectively, after the onset of symptoms. Conclusion: The occurrence of sarcoidosis in association with interferon-alpha therapy for chronic hepatitis C may have been underestimated so far. This could be due to the fact that symptoms of sarcoidosis and common side effects of interferon are similar, and sarcoidosis may occur after the end of interferon therapy. We hypothesize that interferon-a as a potent stimulator for T-helper 1 (Th1) immune responses may trigger the compartmentalized Th1 reaction that has been shown to take place in sarcoidosis.