Table of Contents
Definition / general | Pathophysiology | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative stainingCite this page: Pernick N. CD45RO. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd45ro.html. Accessed January 24th, 2021.
Definition / general
- Marker of activated T cells
- Also called UCHL1, although this is also an abbreviation for ubiquitin carboxyl-terminal esterase L1, a gene expressed in neurons and whose mutations are associated with Parkinson's disease
- Low density of intratumoral CD45RO+ cells was poor prognostic factor for non-metastasized esophageal adenocarcinoma (BMC Cancer 2010;10:608)
- Increased CD45RO+ T cell infiltrate is present in atherosclerosis (Am J Pathol 1992;140:907), diffuse large B cell lymphoma, MALT lymphoma (Am J Pathol 1997;151:1353), Hashimoto’s thyroiditis-interfollicular infiltrate (J Clin Pathol 2004;57:1258), Kikuchi’s disease, molar pregnancy (J Clin Pathol 1999;52:888), ovarian carcinoma (Am J Pathol 1997;150:1723), primary cutaneous neoplasms (Am J Pathol 1993;142:1556) and well nourished vs. malnourished infected children (Clin Exp Immunol 2001;126:461)
- CD4+ CD45RO+ T cells are a major latent viral reservoir in HIV+ individuals (Am J Pathol 1992;140:15)
- Increased percentage of CD45RO+ peripheral blood T cells in patients with preeclampsia (Am J Obstet Gynecol 2002;187:889) and psoriasis (Ann Univ Mariae Curie Sklodowska Med 2001;56:465)
Pathophysiology
- Most regulatory T cells in adults are CD45RO+; percentage increases with age (J Immunol 2010;184:4317)
- Ligand is CD22
- CD45RO+ T cells are more common than naïve T cells (CD45RA+) in inflammatory myopathies (Am J Pathol 1995;146:1178)
Uses by pathologists
- T cell marker for diagnosis and classification of lymphoma
- Identify T cell subsets (i.e. memory T cells)
Microscopic (histologic) images
Positive staining - normal
- Memory and activated T cells, granulocytes, monocytes, macrophages and cortical thymocytes; some B cells
Positive staining - disease
- T cell lymphomas (75%), including angiocentric and angioimmunoblastic (Hum Pathol 2005;36:784), cutaneous T cell, hepatosplenic alpha-beta and gamma-delta and peripheral NOS (Am J Clin Pathol 2010;133:281)
- AML (25%), histiocytic sarcoma (Am J Surg Pathol 2004;28:1133)
- Myeloma (some, both on tumor cells and in infiltrate, J Clin Pathol 1998;51:432)
- Some plasma cell neoplasms
- Also Candida albicans (Am J Clin Pathol 2000;113:59)
Negative staining
- B cells (most), NK cells
- B cell lymphoma (most), carcinoma and autoimmune lymphoproliferative syndrome (Am J Pathol 1998;153:1541)