Successful treatment of primary immune thrombocytopenia in aged patients using clarithromycin

Abstract

Primary immune thrombocytopenia (ITP) is an autoimmune disease induced by autoantibodies against platelets. Helicobacter pylori is closely related to the pathogenesis of ITP, and recent studies have suggested that H. pylori-positive ITP can be successfully treated by eradication therapy against H. pylori. On the other hand, corticosteroids are the standard initial treatment for H. pylori-negative ITP patients. We have already reported three cases of ITP in which platelet counts increased following clarithromycin (CAM) treatment, irrespective of H. pylori infection status. In our previous report, the fact that platelet counts improved after CAM treatment suggested immunomodulatory effects of macrolides as well as antibacterial effects. Here, we report two cases of ITP successfully treated with CAM monotherapy. Case 1, a 75-year-old woman, was referred with purpura. The final diagnosis was H. pyloripositive ITP. The patient could not be treated with eradication therapy because of an allergy to penicillin. The patient was treated using CAM. The platelet count had increased from 1.6 10/mL to 6.0 10/mL after 4 weeks of CAM treatment (Fig. 1A). Case 2, a 77-year-old woman with H. pylori-negative ITP, was admitted with a gradual decrease in platelet count accompanied by purpura.