Thrombocytopenia in children with severe iron deficiency

PURPOSE: Thrombocytopenia has been reported in some children with severe iron deficiency anemia, but the validity of the association and the mechanism of the thrombocytopenia are not well established. Six children with severe iron deficiency and thrombocytopenia are described, and the literature is reviewed. PATIENTS AND METHODS: Clinical, hematologic, and morphologic data were collected and analyzed for six patients referred for evaluation of severe microcytic anemia and thrombocytopenia. RESULTS: The children ranged in age from 14 months to 17 years (median age 27 months) and were otherwise healthy. The iron deficiency was nutritional in four patients younger than 3 years of age and resulted from menstrual blood loss in two teenage girls. The mean initial hemoglobin was 2.5 g/dL (range 1.6-4.7) and the mean initial platelet count was 64 x 109/L (range 11-102). Bone marrow examinations were performed in three patients and showed increased numbers of megakaryocytes. After treatment with therapeutic doses of oral iron, all the patients showed rapid increases in their platelet counts. CONCLUSIONS: These observations validate and extend previous reports of an association between severe iron deficiency and thrombocytopenia. The increased numbers of megakaryocytes and the extremely rapid increase in platelet counts after initiation of iron therapy suggest an essential role for iron in a late stage of thrombopoiesis.