Sarcoidosis and multiple sclerosis: systemic toxicity associated with the use of interferon-beta therapy.

Sarcoidosis is a multi-systemic inflammatory disease of unknown origin characterized by the presence of noncaseating epitheloid cell granulomas in multiple organs. Diagnosis is made on the basis of a compatible clinical-radiological scenario and the histological demonstration of the typical granulomas in the affected tissues. Interferons are immuno-modulators that have been used in a wide range of diseases, including hepatitis C virus infection, multiple sclerosis, and multiple myeloma and other types of tumours, including leukemia, lymphomas, Kaposi's sarcoma, and melanoma. Interferon-alpha-induced sarcoidosis has been reported repeatedly and there are two reports in the literature of cases of pulmonary sarcoidosis treated with interferon-1b therapy: one for advanced renal cell carcinoma and the other for multiple myeloma. A 35-year-old man on chronic immune-modulant Interferon-1b-based therapy for multiple sclerosis presented to the Neurology Unit with mild dyspnoea, dry cough, and transient pain to right upper abdomen. Lungs, spleen, liver, and almost all lymphnode stations of abdomen and mediastinum were clearly involved on ultrasound examination, chest X-ray, and computed tomography. A transbronchial biopsy showed non-caseating granuloma on histopathologic evaluation of the lungs. To the best of our knowledge, this is the first report of a chronic multisystemic sarcoidosis that was associated with interferon-beta treatment.