Severe Thrombocytopenia Due to Iron Deficiency

Abstract

Iron deficiency anemia is commonly associated with thrombocytosis, although severe thrombocytopenia has been reported in rare cases. The differential diagnosis for severe thrombocytopenia (<20 k/μL) includes iatrogenic complications of medications (eg, chemotherapy, heparin), acute leukemias, immune thrombocytopenic purpura (ITP), and thrombotic thrombocytopenic purpura. A 31-year-old woman with a history of menorrhagia and 3 previous cesarean sections was admitted to the emergency department after a routine preemployment health evaluation demonstrated a platelet count of 12 k/μL and hemoglobin of 2.9 g/dL. She ate trays of ice cubes, chalk, and also ingested soap during her last pregnancy 6 years ago. She denied fatigue, jogging twice a week, and had normal menstrual periods. Physical examination demonstrated conjunctival pallor and a systolic murmur but was negative for ecchymosis, purpura, or bleeding. Repeat testing confirmed a platelet count of 10 k/μL. The clinicians requested a single donor platelet (SDP) as prophylaxis for a bone marrow biopsy. The SDP was approved with the caution that the diagnosis of Evan syndrome (ITP with a warm autoimmune hemolytic anemia) or ITP be considered. The direct antiglobulin test was negative. Peripheral smear was free of schistocytes but showed microcystosis and hypochromia. Iron studies showed Fe of less than 10 μg/dL, unsaturated iron binding capacity of 393 μg/dL, ferritin of less than 4 ng/mL, and a reticulocyte count of 1.47%, consistent with iron deficiency. The patient was transfused with 3 U of RBCs and started on intravenous iron. Bone marrow biopsy revealed a “hypercellular bone marrow with mild dyspoiesis and absent iron stores” and a normal karyotype. After a month of oral iron therapy, the platelet count normalized and the hemoglobin improved to 7.2 g/dL. Severe iron deficiency can affect all 3 hematopoietic cell lines and can present with severe thrombocytopenia mimicking ITP.