Successful treatment in a case of Propionibacterium acnes-associated sarcoidosis with clarithromycin administration: a case report

INTRODUCTION Sarcoidosis is recognized as a multiorgan disorder characterized by the presence of non-caseating granulomas in the involved tissues. It has been suggested that sarcoidosis might be due to the exposure to infectious or non-infectious agents in genetically susceptible individuals. In particular, Propionibacterium acnes and Mycobacterium tuberculosis have been considered causative microorganisms. We report a case of P. acnes-associated sarcoidosis in which a drastic improvement was achieved with clarithromycin administration. A possible mechanism of clarithromycin action is discussed. CASE PRESENTATION A 78-year-old Japanese-Mongoloid woman with P. acnes-associated sarcoidosis presented with a persisting fever, joint pains and generalized lymph node swelling. The diagnosis of sarcoidosis was confirmed by pathological and immunohistochemical studies of a biopsied lymph node. In this case, an oral administration of clarithromycin was applied. Soon after the initiation of this treatment her symptoms as well as lymph node swelling disappeared. The clarithromycin treatment was discontinued 3.5 months after its initiation. She is currently in good condition. The pathological analysis of her lymph node, which was obtained during the clarithromycin treatment, suggested an apoptosis-inducing effect of clarithromycin on the sarcoid granulomas. CONCLUSIONS Clarithromycin was found to be effective for treating sarcoidosis and seems to have important pharmacological effects such as immunosuppression, immunomodulation and induction of apoptosis in addition to its antimicrobial role. In this case, apoptosis in the sarcoid granulomas induced by clarithromycin administration might have resulted in satisfactory improvement.