Platelet surface antigen (PSA) (PSA)

Platelet surface antigens are a diverse group of membrane-bound proteins, primarily glycoproteins, that facilitate the essential functions of platelets in blood clotting, vascular integrity, and immune modulation (Source: NIH, 2024). Key members include the integrin alpha-IIb/beta-3 (GPIIb/IIIa) complex, which serves as the final common pathway for platelet aggregation, and the GPIb-IX-V complex, which mediates initial adhesion to von Willebrand factor at sites of vascular injury (Source: Wikipedia, 2024). These antigens are clinically significant as they are the primary targets of potent antiplatelet drugs, such as abciximab, eptifibatide, and tirofiban, which are used to treat acute coronary syndromes and prevent thrombosis during percutaneous coronary intervention (Source: StatPearls, 2023). Additionally, polymorphisms within these proteins, known as Human Platelet Antigens (HPAs), can elicit alloimmune responses leading to conditions like neonatal alloimmune thrombocytopenia (NAIT) and platelet transfusion refractoriness (Source: NIH, 2024). Beyond hemostasis, these surface molecules are involved in inflammation and cancer metastasis, making them versatile targets for diagnostic biomarkers and novel site-specific therapeutic delivery systems, such as antibody-drug conjugates (Source: Thno.org, 2019). This target entry is considered a group classification rather than a single molecular entity.

Other names

Human platelet antigensHPAPlatelet glycoproteinsPlatelet membrane glycoproteinsPlatelet specific antigensPlatelet surface antigensCD41CD61CD42bIntegrin alpha-IIb/beta-3GPIIb/IIIaPlatelet membrane protein

Inhibition of platelet aggregation and activation through the blockade of surface receptors or their signaling pathways (Source: StatPearls, 2023; Dovepress, 2025).