CD Markers
CD42a

Author: Nat Pernick M.D. (see Authors page)

Revised: 7 January 2016, last major update December 2010

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: CD42 [title]


Related: CD42b, CD42c, CD42d

Cite this page: CD42a. PathologyOutlines.com website. http://pathologyoutlines.com/topic/cdmarkerscd42.html. Accessed August 18th, 2017.
Definition / general
  • CD42a-d complex is receptor for von Willebrand factor and thrombin
  • Also called platelet glycoprotein GPIX, GP9
  • Absence of CD42 complex (mutations in CD42a-c) causes Bernard-Soulier syndrome (giant platelet syndrome, OMIM #231200), a bleeding disorder with thrombocytopenia, prolonged bleeding time and giant platelets
  • OMIM #173515
Diagrams / tables
Missing Image

CD42a-d complex

Pathophysiology
  • CD42a-d complex is receptor for von Willebrand factor and thrombin
  • This complex mediates adhesion of platelets to subendothelial matrices that are exposed in damaged endothelium and amplifies platelet response to thrombin
  • GP-IX (CD42a) is a small membrane protein glycoprotein that forms a non-covalent complex with GP-Ib (CD42b)
  • Actual binding site of vWF and thrombin is on CD42b
Uses by pathologists
  • No significant clinical use by pathologists
Positive staining - normal
  • Platelets and megakaryocytes
Negative staining
  • Red blood cells, T cells