CD Markers

Reviewer: Charanjeet Singh, M.D. (see Reviewers page)

Revised: 12 October 2015, last major update January 2011

Copyright: (c) 2002-2015,, Inc.

PubMed Search: CD33 [title]
Cite this page: CD33. website. Accessed July 21st, 2018.
Definition / general
  • Classic myeloid antigen (also CD13)
  • Glycosylated transmembrane protein of sialic acid binding immunoglobulin-like lactic (siglec) family
  • May mediate cell to cell adhesion; acts as receptor that inhibits the proliferation of normal and leukemic myeloid cells
Clinical features
Uses by pathologists
  • Distinguish myeloid (CD33+) and lymphoid leukemias (CD33-)
  • Identify monocytes by flow cytometry
Positive staining - normal
Positive staining - disease
Negative staining
  • Pluripotent stem cells, B cells
  • Most B and T cell lymphomas, blastic NK lymphoma (usually)
  • Not expressed outside hematopoietic system
Additional references