Management challenge of a rare concomitant platelet glycoprotein IV/CD36 and IIb/IIIa deficiencies: Case illustration.

Introduction/background: Platelet membrane glycoproteins (GPs) serve several functions, the most significant of which is their role in primary hemostasis. Among these, GP IIb/IIIa is the primary fibrinogen receptor and is essential for platelet aggregation. Its deficiency or dysfunction impairs platelet aggregation, leading to Glanzmann thrombasthenia, a rare autosomal recessive bleeding disorder. In contrast, platelet GP IV (CD36) has a limited role in primary hemostasis. While also rare, CD36 deficiency has a disproportionately higher prevalence in individuals of East Asian, African, and Arabian descent. Patients with platelet GP deficiencies can develop antibodies against the missing GPs, leading to immune-mediated platelet transfusion refractoriness (PTR). Consequently, they are unresponsive to platelet transfusions when mostly needed.

Case Presentation: Here we present the case of an Egyptian male with a lifelong history of an incompletely characterized bleeding disorder who presented for pre-surgical evaluation. We diagnosed the patient with Type I Glanzmann thrombasthenia. Further evaluation revealed anti-CD36 antibodies, leading to the discovery of a concurrent platelet CD36 deficiency. The dual GP deficiency significantly complicated his management, as finding crossmatch-compatible platelets was challenging due to the rarity of CD36-deficient blood donors in the United States.

Discussion/conclusion: Awareness of coexisting platelet disorders and their ramifications is limited, mostly because these are stochastically rare (~1 in 100 million for the present case). This case highlights the importance of thoroughly evaluating platelet glycoprotein deficiencies, particularly in individuals with severe bleeding disorders and from ethnic backgrounds with a predisposition to specific platelet disorders. Such an approach can prevent future platelet antibody formation or reduce bleeding risk with pre-existing antibodies.