Review Question - QID 101327

Glanzmann’s thrombocytopenia is a congenital platelet disorder in which platelet membranes are deficient in GpIIb/IIIa receptors. GpIIb/IIIa receptors allow platelets to form aggregation networks through linkage to fibrinogen.

Patients with Glanzmann’s thrombasthenia present with mucocutaneous bleeding at an early age with symptoms such as menorrhagia, epistaxis, gingival bleeding, and increased post-operative bleeding. Peripheral blood smear shows a lack of platelet clumping. Bleeding time is prolonged while platelet counts are normal. This disease is inherited in an autosomal recessive pattern or it may also be acquired as an autoimmune disorder.

Incorrect Answers:
Answer 1: A deficiency of factor VIII causes hemophilia A. The disease presents with hemarthroses, easy bruising, and increased PTT.
Answer 2: Thrombotic thrombocytopenic purpura (TTP) is marked by a deficiency of ADAMTS 13, a von Willebrand Factor metalloprotease. This disease decreases platelet count.
Answer 3: A lack of Gp1b receptors and an associated inability of platelets to adhere to collagen causes Bernard-Soulier disease. The disease decreases platelet count.
Answer 4: Anti-GIIb/IIIa antibodies cause idiopathic thrombocytopenic purpura (ITP). Platelet survival and platelet count are markedly decreased, while peripheral megakaryocytes are increased.