CD Markers
CD45RB

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

Revised: 31 December 2015, last major update October 2013

Copyright: (c) 2003-2015, PathologyOutlines.com, Inc.

PubMed Search: CD45RB[title]

Related topics: CD45, CD45RO, CD45RA, CD45RC

Definition / General
  • CD45 isoform generated by alternative mRNA splicing of exon 5, leading to change in the extracellular domain of the molecule (J Exp Med 1987;166:1548)
  • Influx of CD4+, CD45RB high T cells is present in inflammatory bowel disease; may be important in pathogenesis as they produce more proinflammatory cytokines than CD4+ CD45RB low T cells (J Leukoc Biol 2004;75:1010)
Diagrams / Tables

CD45RB expression changes during germinal center reaction

Pathophysiology
  • CD45 is a high molecular weight transmembrane protein with intrinsic tyrosine phosphatase activity
  • CD45 is heavily glycosylated, and expressed at high levels on nucleated hematopoietic cells
  • CD45 isoforms, including CD45RB, are generated by alternative mRNA splicing of exons 4 (CD45RA), 5 (CD45RB) and 6 (CD45RC), leading to changes in the extracellular domain of the molecule
  • Down regulated in memory cells
Uses by Pathologists
  • No significant clinical use by pathologists
Positive Staining - Normal
  • Similar staining as CD45, except not expressed in Langerhans cells and some T cells
  • B cells, most T cells, monocytes, macrophages and granulocytes (weak)
Positive Staining - Disease
  • Most leukemias and lymphomas
Negative Staining
  • Some T cells; Langerhans cells, platelets
  • Plasma cell neoplasms, Reed-Sternberg cells, some lymphoblastic lymphomas and some anaplastic large cell lymphomas