Researchers reported a case study of severe platelet transfusionPlatelet transfusion A treatment for newborns with very low platelet counts that ideally uses HPA-compatible or washed maternal platelets. failure associated with anti-CD36 antibodies. According to the authors, this is the first reported case of anti-CD36-associated platelet transfusion refractoriness (PTR) in a Brazilian patient.
Anti-CD36 antibodies have also been implicated in some cases of fetal and neonatal alloimmune thrombocytopenia (FNAIT). People with CD36 deficiency can become sensitized to the protein after exposure to CD36-positive platelets through a blood transfusion or pregnancy. During pregnancy, a mother who lacks CD36 may develop antibodies against CD36 on her baby’s platelets, potentially leading to FNAITFetal and neonatal alloimmune thrombocytopenia A rare condition in which a mother’s immune system attacks fetal platelets, leading to dangerously low platelet levels before and/or after birth..
The study, published in Vox Sanguinis, described a 48-year-old woman with CD36 deficiency, a condition in which platelets lack a protein called CD36 on their surface. The deficiency is more frequently reported in Asian, African and Arabian populations.
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After receiving multiple blood transfusions during leukemia treatment, the patient was found to have anti-CD36 antibodies, which can recognize and target donor platelets carrying the protein. Despite repeated transfusions, her platelet counts failed to increase, a condition known as platelet transfusion refractoriness.
During hospitalization in June 2025, the patient’s platelet countPlatelet count A measure of how many platelets are in the blood. FNAIT is characterized by severely reduced counts in a fetus or newborn. remained below 5,000/µL (the normal range is approximately 150,000–450,000/µL). At that time, she had bleeding in her eyes, mouth and nose, as well as petechiae on her skin.
Due to the persistent thrombocytopeniaThrombocytopenia A platelet count that is lower than normal. and bleeding, the care team performed platelet antibody testing. They found anti-CD36 antibodies but no antibodies against human leukocyte antigen (HLA) proteins, a more common cause of immune PTR. Like CD36, HLA proteins are found on platelets and can be targeted by antibodies.
Learn more about why DNA tests may miss CD36 deficiency linked to FNAIT
The tests also showed no detectable CD36 expression on her platelets, suggesting that anti-CD36 alloimmunizationAlloimmunization The process by which the mother becomes sensitized to fetal platelet antigens and begins producing alloantibodies. This is what causes FNAIT. was the predominant immune contributor to PTR.
Doctors also tried to find compatible platelet donors, but were unsuccessful. Even her brother’s platelets were incompatible. He had matching HLA, but his platelets still expressed CD36.
The care team continued administering the available, incompatible platelet units. However, despite the team’s efforts, the patient’s platelet counts remained low, and she died from progression of her hematologic disease in September 2025.
The authors highlighted the importance of considering a wider range of platelet antigens when investigating PTR and note the need for more diverse platelet donor registries: “the scarcity of CD36-negative platelets underscores the need for ethnically diverse rare-donor registries.”
