CD Markers
CD45RA

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: CD45RA[title]

Related topics: CD45, CD45RO, CD45RB, CD45RC

Definition / General
Diagrams / Tables

Subsets of T cells

Pathophysiology
  • CD45 isoforms [functionally similar proteins with similar but not identical amino acid sequence], including CD45A, 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 (J Exp Med 1987;166:1548)
  • CD45RA+ T regulatory cells are converted to CD45RO+ T regulatory cells after activation (J Immunol 2010;184:4317)
  • High molecular weight transmembrane protein with intrinsic tyrosine phosphatase activity
  • Heavily glycosylated, and expressed at high levels on nucleated hematopoietic cells
Uses by Pathologists
  • Differentiate naive T cells (CD45RA+) from memory T cells (CD45RO+), but not in adult allogeneic hematopoietic cell transplant recipients (Bone Marrow Transplant 2003;32:609)
Micro Images

Images hosted on other servers:

Normal lymph node (B cells are positive, most T cells are negative, fig 4b)

Intraepidermal T Cells in fixed drug eruption lesions (fig d)

Papulonodular lesion show the dermal and intraepithelial neoplastic lymphocytes (fig C)

Positive Staining - Normal
  • B cells, NK cells, naive / resting T cells (those not exposed to antigens), medullary thymocytes and plasmacytoid dendritic cells (Am J Pathol 2001;159:237)
Positive Staining - Disease
Negative Staining
  • Basophils, endothelial cells, Langerhans cells, memory T cells (usually), most T cell lymphomas and most plasma cell neoplasms