Successful Treatment for Idiopathic Thrombocytopenic Purpura in a Japanese Monkey

  • Tohru Kimura Center for Experimental Animals, National Institutes of Natural Sciences, Aichi


In human beings and dogs, idiopathic thrombocytopenic purpura (ITP) is a well-known disease in which antibodies bound to the surface platelets result in premature platelet destruction by macrophages. However, there is a paucity of information dealing with ITP in non-human primates, especially the Japanese monkey (Macaca fuscata). The case is described of a female Japanese monkey suffering from ITP in the Center for Experimental Animals. Physical examinations revealed characteristic findings such as mucosal and cutaneous petechiae, ecchymoses and purpura, epistaxis and mucous membrane pallor. The monkey had severe thrombocytopenia (10,000/μl) on initial hematological examination. Immunosuppressive glucocorticoid therapy had remarkable effects on this condition, with the platelet count rapidly reaching the normal range. On tapering the dose of predonisolone, the number of platelets decreased and the monkey suffered a relapse of ITP. Although immunosuppressive therapy was resumed with the initial dose of predonisolone, the monkey was relatively slow to respond. The initial treatment revealed an apparently faster increase in platelet count than the second treatment following the recurrence of ITP. The monkey remained in complete remission for more than one year after cessation of predonisolone treatment. In blood coagulation profiles and serum biochemical findings, there were no marked changes throughout this investigation. Neither endoscopy nor the stool antigen test provided evidence that natural infection with Helicobacter pylori caused ITP in this monkey. This is the first case of successful treatment for idiopathic thrombocytopenic purpura in a Japanese monkey.