Interferon-alpha-associated sarcoidosis responsive to infliximab therapy

Sarcoidosis, a multisystem disease characterized by noncaseating granulomas, has been reported to be associated with interferon alpha (IFN-alpha) therapy for hepatitis C infection. INF-alpha is known to stimulate T helper cells with a Th1 profile immune response, which is the key immunologic event of a sarcoid granuloma formation. We report a patient treated with IFN-alpha who developed hypercalcemia and renal insufficiency as presenting clinical manifestation of sarcoidosis. Prednisone therapy was effective in controlling hypercalcemia but had to be discontinued due to an increase in hepatitis C viral RNA count. Infliximab, a chimeric monoclonal antibody directed against tumor necrosis factor alpha was used as therapy in our patient for its known potent anti-inflammatory effects. The patient received three doses of infliximab (5 mg/kg) and achieved a rapid decline in serum calcium to normal levels in 7 days; the serum calcium level has remained normal 3 months after the last infusion.