Successful treatment of cyclic thrombocytopenia with thrombopoietin-mimetic agents: A report of two patients

Cyclic thrombocytopenia (CTP), characterized by periodic oscillations of the platelet count with cycles of 20-40 days, is a rare disorder that has demographic and clinical features similar to immune thrombocytopenic purpura (ITP) [1]. Like ITP, the pathogenesis can involve both accelerated platelet destruction and insufficient platelet production [1]. However, CTP appears to be less responsive to conventional therapies used for ITP [1]. Thrombopoietin (TPO)-mimetic agents have recently been documented to be effective for most patients with ITP [2-5]. We present two women with CTP who have been effectively treated with TPO-mimetic agents following failure of multiple treatments for ITP. The first report is an 11 year follow-up of a patient whose initial 1 year of treatment with recombinant pegylated human megakaryocyte growth and development factor (PEG-rHuMGDF) has been previously reported [6]. She was successfully treated with PEG-rHuMGDF for 12 years, and is currently treated with romiplostim. The second patient has been successfully treated with romiplostim for 3 years. TPO-mimetic agents can provide effective long-term treatment for patients with severe and symptomatic CTP.