Table of Contents
Definition / general | Essential features | Terminology | Pathophysiology | Clinical features | Interpretation | Uses by pathologists | Microscopic (histologic) images | Virtual slides | Positive staining - normal | Positive staining - disease | Negative staining | Sample pathology report | Board review style question #1 | Board review style answer #1Cite this page: Sulyok M, Schürch CM. CD23. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd23.html. Accessed December 19th, 2024.
Definition / general
- CD23 is a low affinity immunoglobulin E (IgE) receptor
- Found on mature B cells, activated macrophages, eosinophils, follicular dendritic cells (FDCs), platelets and megakaryocytes (Sci Rep 2016;6:25629, Immunol Res 1992;11:252, World J Surg Oncol 2019;17:115, Eur J Immunol 1997;27:2212)
Essential features
- CD23 is a low affinity IgE receptor
- Differentiates small lymphocytic lymphoma (SLL) / chronic lymphocytic leukemia (CLL) (CD23+) from mantle cell lymphoma or MALT lymphoma (CD23-)
- B cell marker, particularly for SLL / CLL, mediastinal large B cell lymphoma, lymphoplasmacytic lymphoma and diffuse follicular lymphoma (Mod Pathol 2012;25:1637, Blood Adv 2020;4:5652)
- Distinguish nodal marginal zone lymphoma from follicular lymphoma by identifying a disrupted follicular dendritic cell pattern (Int J Surg Pathol 2005;13:73)
Terminology
- Low affinity IgE receptor, Fc fragment of IgE receptor, FCER
Pathophysiology
- Secretable type C lectin
- After physiologic germinal cell development, the follicular dendritic cell meshwork expands and follicular dendritic cells in the light zone of the germinal center become CD23 positive
- CD23 acts as a B cell growth and activation factor, promoting differentiation into plasma cells
- Shows variability in flow cytometry expression between specimens from same patient (Am J Clin Pathol 2002;117:615)
- CD21, CD23 and CD35 are dendritic cell markers
- Interactions with IgE:
- Membranous form regulates IgE synthesis through CD21 and IgE binding (J Exp Med 2005;202:751, Acta Crystallogr F Struct Biol Commun 2014;70:305)
- Soluble form also controls IgE synthesis and homeostasis in B cells (J Immunol 2012;188:3199)
- Membranous form mediates IgE related immune responses (Clin Rev Allergy Immunol 2005;29:61)
- IgE binding site of CD23 has extensive conformational plasticity (Mol Immunol 2013;56:693)
- Presentation of extremely low doses of antigen to T cells is enhanced by IgE dependent antigen focusing to CD23 (Immunology 2001;103:319)
- CD23 is noncovalently associated with HLA-DR and plays a role in endocytosis and recycling of the complex, which may contribute to the efficiency of antigen presentation (Immunology 2001;103:319)
Clinical features
- High expression on B cells in peripheral blood is associated with bullous pemphigoid (J Dermatol Sci 2004;35:53)
- CD23 antibodies may decrease adherence of Plasmodium falciparum infected erythrocytes (Cell Microbiol 2004;6:839)
- CD23 levels correlate with Plasmodium falciparum malaria severity (Acta Trop 2016;154:25)
- CD23 mediates antimycobacterial activity of human macrophages (Infect Immun 2009;77:5537)
- Polymorphisms are associated with atopy, increased risk of exacerbations in patients with asthma and high serum IgE levels (Am J Respir Cell Mol Biol 2014;50:263)
- Mantle cell lymphoma:
- Usually CD23-
- May have CD23 present with dim intensity by flow cytometry; however, these cases have high cyclin D1 levels (Am J Clin Pathol 2003;120:760, Am J Clin Pathol 2001;116:893, Am J Clin Pathol 2002;117:237)
- CD23+ cases may have better prognosis (Am J Clin Pathol 2008;130:166, Hum Pathol 2019;89:71, Curr Oncol Rep 2021;23:102)
- Rarely has CD23+ cells in peripheral blood (Am J Clin Pathol 2002;118:758)
- Chronic lymphocytic leukemia / CLL:
- High soluble CD23 is associated with aggressive disease and poorer prognosis (Leuk Lymphoma 2002;43:549, Clin Lab Haematol 2006;28:30, Cytometry B Clin Cytom 2014;86:91)
Interpretation
- Diffuse cell membrane staining, cytoplasmic staining
Uses by pathologists
- CD21, CD23 and CD35 are follicular dendritic cell markers
- Differentiate SLL / CLL (CD23+) versus mantle cell lymphoma or MALT lymphoma (CD23-)
- B cell marker, particularly for SLL / CLL, mediastinal large B cell lymphoma, lymphoplasmacytic lymphoma and diffuse follicular lymphoma (Mod Pathol 2012;25:1637, Blood Adv 2020;4:5652)
- Distinguish nodal marginal zone lymphoma from follicular lymphoma by identifying a disrupted follicular dendritic cell pattern in marginal zone lymphoma (Int J Surg Pathol 2005;13:73)
Microscopic (histologic) images
Virtual slides
Positive staining - normal
- Activated mature B cells expressing IgM or IgD (particularly mantle cells), activated monocytes / macrophages, T cell subsets, platelets, eosinophils, Langerhans cells, follicular dendritic cells and intestinal epithelium (encodes IgE receptor) (Gastroenterology 2005;129:928, Sci Rep 2016;6:25629, Immunol Res 1992;11:252, World J Surg Oncol 2019;17:115, Eur J Immunol 1997;27:2212)
Positive staining - disease
- B cell CLL / SLL (almost all cases; high levels) (Leuk Res 2002;26:809, Hum Pathol 1999;30:648)
- Atypical cases of CLL / SLL may have higher levels (Am J Clin Pathol 2001;116:655)
- Follicular dendritic cell sarcoma (Am J Surg Pathol 2001;25:721, Pathologica 2021;113:316, Cytopathology 2022;33:119, Medicine (Baltimore) 2021;100:e27209)
- Mediastinal large B cell lymphoma (70%) (Histopathology 2004;45:619, Blood 2021;138:136)
- Lymphoplasmacytic lymphoma (61%, usually dim intensity by flow cytometry) (Am J Clin Pathol 2005;124:414, Clin Lymphoma 2005;5:246)
- Hairy cell leukemia (17%) (Am J Clin Pathol 2006;125:251)
- Diffuse large B cell lymphoma (16%) (Histopathology 2010;56:217)
- Primary cutaneous follicle center lymphoma (38%) (Am J Surg Pathol 2002;26:733)
- Plasma cell myeloma (10%) with chromosome 11 abnormalities, with t(11;14)(q13;q32) (40%) (Br J Haematol 2010;149:292, Ann Diagn Pathol 2011;15:385)
- Plasma cell leukemia (Br J Haematol 2010;150:724)
- Postsplenectomy polyclonal B cell lymphocytosis (Int J Lab Hematol 2022;44:e32)
Negative staining
- Basophils, resting B cells
- Other B cell lymphomas, including Burkitt lymphoma, mantle cell lymphoma and marginal zone lymphoma; HHV8 associated germinotropic lymphoproliferative disorder and acute precursor B cell lymphoma / leukemia (Am J Surg Pathol 2005;29:1652, Am J Surg Pathol 1999;23:59, Mod Pathol 1998;11:967, Int J Clin Exp Pathol 2021;14:375, Am J Surg Pathol 2017;41:795, Am J Clin Pathol 2001;116:673, Curr Oncol 2021;28:5148)
- Most T cell lymphomas, inflammatory fibroid polyps of the gastrointestinal tract (although of dendritic cell origin), indeterminate dendritic cell tumor and interdigitating dendritic cell sarcoma (Am J Surg Pathol 2004;28:107, Hemasphere 2020;5:e511, J Int Med Res 2018;46:4791)
- Blastic plasmacytoid dendritic cell neoplasm (Clin Case Rep 2018;6:770)
- Epithelioid sarcoma (Am J Clin Pathol 2021;156:229)
- Classic Hodgkin lymphoma (Histopathology 2010;56:217)
- Plasmablastic lymphoma (Rev Esp Enferm Dig 2021 Dec 22 [Epub ahead of print])
- Abnormally developed CD23 negative B cells in AIOLOS defect patients (J Exp Med 2021;218:e20211118)
Sample pathology report
- Left axillary lymph node, excision:
- Left axillary lymph node excision infiltrated by chronic lymphocytic leukemia / small lymphocytic lymphoma (CLL / SLL) with large proliferation centers; no signs of Richter transformation (see comment)
- Comment: A large lymph node with disrupted architecture due to a lymphocytic infiltrate with a vaguely nodular growth pattern. The infiltrate consists of small cells with round nuclei, mature chromatin and a barely visible cytoplasmic border. The nodular parts (so called proliferation centers) consist of small and large cells and some large prominent paraimmunoblasts.
- Immunohistochemically, the infiltrate is positive for CD20, CD5, CD23 and BCL2. The staining for CD3 shows numerous accompanying reactive T lymphocytes. The stains for cyclin D1, BCL6 and CD10 remain negative in the lymphocytic infiltrate but BCL6 and CD10 are positive in a few residual reactive germinal centers. The proliferation is high and polarized in the residual germinal centers and somewhat increased in the proliferation centers with a proliferation rate of about 20%.
Board review style question #1
Which tumor typically exhibits CD23 positivity?
- Blastic plasmacytoid dendritic cell neoplasm
- Follicular dendritic cell sarcoma
- HHV8 associated germinotropic lymphoproliferative disorder
- Indeterminate dendritic cell tumor
- Interdigitating dendritic cell sarcoma
Board review style answer #1