In immune thrombocytopenic purpura (ITP), platelets are destroyed by autoantibodies targeting which platelet surface glycoproteins?

• A GPIa/IIa (collagen receptor)
• B P-selectin (CD62P)
• C PECAM-1 (CD31)
• D GPIIb/IIIa (integrin αIIbβ3) and GPIb/IX/V complex ✓

Explanation

In ITP, IgG autoantibodies target GPIIb/IIIa (the fibrinogen/vWF receptor, most common target) and/or GPIb/IX/V complex (vWF receptor); antibody-coated platelets are cleared by Fc-receptor-mediated phagocytosis in the spleen (extravascular destruction) and also by complement-mediated lysis. Additionally, anti-GPIb/IX antibodies may impair megakaryocyte platelet production. Thrombopoietin-receptor agonists (romiplostim, eltrombopag) overcome the production defect. GPIa/IIa is a collagen receptor not the primary ITP target. P-selectin (CD62P) and PECAM-1 are not established primary ITP antigens.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.