CD Markers
CD45RA
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: CD45RA[title]
Related topics: CD45, CD45RO, CD45RB, CD45RC
CD45RA
Author: Nat Pernick, M.D.
Last author update: 1 October 2013
Last staff update: 9 February 2022
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: CD45RA[title]
Related topics: CD45, CD45RO, CD45RB, CD45RC
Table of Contents
Definition / general | Pathophysiology | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative stainingCite this page: Pernick N. CD45RA. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd45ra.html. Accessed January 15th, 2025.
Definition / general
- Marker of naive T cells
- Also called protein tyrosine phosphatase receptor type C
- Cord blood has higher percentage of CD45RA helper T cells than adult blood (Am J Clin Pathol 1996;105:38)
- In adults, CD45RA+ cells may prevent autoimmune disease (Blood 2006;107:2830)
- Reduced numbers of CD45RA+ CD4+ T cells are associated with children with biliary atresia (Transplant Proc 2003;35:3026); primary biliary cirrhosis (Scand J Gastroenterol 2003;38:421), fetal distress (Biol Neonate 2004;85:61) and preeclampsia (Am J Obstet Gynecol 2002;187:889)
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)
Microscopic (histologic) images
Images hosted on other servers:
Intraepidermal T cells in fixed drug eruption lesions (fig d)
Papulonodular lesion show dermal, intraepithelial neoplastic lymphocytes
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
-
Hematologic malignancies:
- B cell lymphomas (most), hairy cell leukemia (Hum Pathol 1992;23:172)
- CD8+ primary cutaneous T cell lymphoma (Am J Pathol 1999;155:483)
- CD4(+) CD56(+) lineage-negative malignancies (Am J Surg Pathol 2005;29:1274)
- Progressive transformation of germinal centers
- Reed-Sternberg cells in lymphocyte predominant Hodgkin’s lymphoma (Am J Surg Pathol 1999;23:27)
- Autoimmune lymphoproliferative syndrome (Am J Pathol 1998;153:1541)
- Effector memory T cells in lesional epidermis (Am J Pathol 2002;161:1337)
- CD4+ memory T cells after bone marrow grafts (Eur J Immunol 1999;29:3987)
- Terminally differentiated CD8+ memory T cells (Arthritis Res Ther 2003;5:R91)
Other:
Negative staining
- Basophils, endothelial cells, Langerhans cells, memory T cells (usually), most T cell lymphomas and most plasma cell neoplasms
