CD Markers

Last author update: 1 August 2013
Last staff update: 14 May 2021

Copyright: 2002-2024,, Inc.

PubMed Search: CD4[title]

Nat Pernick, M.D.
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Cite this page: Pernick N. CD4. website. Accessed April 14th, 2024.
Definition / general
  • Marker of T helper cells, important in T cell activation and receptor for HIV (Wikipedia, OMIM #186940)
  • Also called OKT4
  • At #12p13.31
  • Nonpolymorphous glycoprotein belonging to immunoglobulin superfamily (Cell 1985;42:93)
  • Expressed on surface of T helper cells; serves as coreceptor in MHC class II-restricted antigen induced T cell activation
  • CD4+ CD25+ FOXP3+ regulatory T cells maintain peripheral tolerance and prevent autoimmunity (Curr Top Microbiol Immunol 2005;293:115), and may be prognostic factor in malignancies (Mod Pathol 2013;26:448, J Clin Invest 2013;123:2873)
  • Serves as HIV receptor on T cells, macrophages and brain
    • Downregulated by HIV proteins during AIDS progression (J Virol 2003;77:11536, J Biol Chem 2003;278:33912)
    • Normally CD4 > CD8; in HIV patients, CD4 / CD8 ratio is inverted (i.e. CD4 < CD8) and patients are at risk for opportunistic infections, particularly if CD4 < 200
  • Homologous to CD223
  • Interpretation: staining is usually cytoplasmic and has membrane accentuation
Diagrams / tables

Images hosted on other servers:
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CD4+ T cell and antigen presenting cell

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CD4 acting as HIV receptor

Uses by pathologists
Microscopic (histologic) images

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CNS: acute demyelinating disease (fig 12)

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Joint: rheumatoid arthritis (fig B)

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Lymph node: atypical paracortical hyperplasia (fig B)

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Salivary gland: Sjögren syndrome (fig B)

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Small bowel: T cell lymphoma (left: fig D; middle: fig D); right - stomach (fig C)

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Soft tissue: inflammatory myopathy

Flow cytometry images

Case #36

Soft tissue mass: anaplastic large cell lymphoma

Positive staining - normal
  • T helper cells, thymocytes (80 - 90%), granulocytes, macrophages, Langerhans cells and dendritic cells
  • Expressed in specific regions of brain
Positive staining - disease
  • Many post-thymic T cell leukemia / lymphomas and T cell lymphoproliferative disorders
  • Dendritic / histiocytic neoplasms
    • Blastic plasmacytoid dendritic cell neoplasm
    • Granulomatous histiocytic lymphoma / sarcoma
  • Other hematologic / inflammatory lesions
Negative staining
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