Refractory platelet transfusion in a patient with CD36 deficiency due to pseudothrombocytopenia.

Type I CD36 deficiency is defined by the absence of CD36 on both platelets and monocytes. Pseudothrombocytopenia (PTCP) is characterized by a false reduction in the number of platelets in ethylenediaminetetraacetic acid (EDTA)-anticoagulated blood. Here we report a rare case of concomitant CD36 deficiency and PTCP. The patient was a 7-year-old boy who suffered comminuted fractures of the left humeral condyle. In the pre-operative examination, he was found to have thrombopenia and assumed to have idiopathic thrombocytopenic purpura. After immunotherapy and platelet transfusion, the platelet count remained low, suggesting that the patient was refractory to platelet transfusion. Serum was collected for the detection of platelet antibodies, and antibodies against CD36 were found. Flow cytometry verified the absence of CD36 on both the platelets and monocytes of this patient. However, the platelet count was normal when capillary blood smears were analysed; in addition, platelet coagulation was noted under the microscope when EDTA-anticoagulated peripheral blood was used. The patient underwent surgery without platelet transfusion and recovered uneventfully.