Clinical analysis and TPO levels in three patients with refractory thrombocytopenia

Refractory thrombocytopenia (RTC) is a counter-concept to refractory anemia, which is characterized by isolated thrombocytopenia associated with clonal chromosomal abnormality. The diagnosis of RTC is difficult to establish based on morphologic features alone. And steroid therapy for RTC is often ineffective. We examined 3 patients with RTC to identify its characteristics and measured serum thrombopoietin levels. The mean platelet count was 5.1 x 10(4)/microl and the mean age was 64 years. None of our patients had clinical nor laboratory evidence of liver dysfunction, renal disease or disseminated intravascular coagulation. All patients were negative for antiplatelet antibody, PA-IgG and anticardiolipin-beta2GPI antibody. Leukocyte alkaline phosphatase level was low in two patients. Clonal chromosomal abnormalities of different types were detected in all patients. Bone marrow smears showed micromegakaryocytes. But there were no apparent morphological abnormalities of erythroid and granuloid series. Thrombopoietin levels, as determined by enzyme-linked immunosorbent assay, varied from <0.2 to 1.40 fmol/ml. We could not find the screening tool of RTC. In conclusion, there is a need to identify RTC from isolated thrombocytopenia because the patients with RTC don't have good prognosis as patients with isolated thrombocytopenia. Cytogenetic analysis is necessary to establish the diagnosis of RTC. We recommend that a patient above 50 years of age presenting with isolated thrombocytopenia and a low leukocyte alkaline phosphatase score should be suspected of having RTC.