REA185 recognizes human CD42b, a 145 kDa, single-pass type I membrane protein. Expression of CD42b is found on platelets and megakaryocytes. CD42b, the α chain, together with the β chain (CD42c), forms the heterodimer, glycoprotein Ib (GP Ib). The GP Ib receptor complex further includes association of the alpha and beta subunits with platelet glycoprotein IX and glycoprotein V and this complex serves as the receptor for von Willebrand factor (VWF). The interaction of the GP Ib-IX-V complex to VWF initiates initial platelet adhesion to vascular subendothelium after vascular injury, platelet activation, thrombosis, and hemostasis. Other known ligands for GPIb–IX–V include α-thrombin, clotting factors XI/XIIa, and high-molecular weight kininogen. Additional information: Clone REA185 displays negligible binding to Fc receptors.
Reagent can be used for immunophenotyping by flow cytometry. Abnormal numbers of cells expressing this antigen or aberrant expression levels of the antigen can be expected in some disease states. It is important to understand the normal expression pattern for this antigen and its relationship to expression of other relevant antigens in order to perform appropriate analysis.
Expression of CD42b may be used as aid to diagnostic in the characterization of samples from individuals suspected with hematologic neoplasia.