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]
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