Table of Contents
Definition / general | Pathophysiology | Clinical features | Uses by pathologists | Positive staining - normal | Positive staining - disease | Negative staining | Additional referencesCite this page: Singh C. CD33. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd33.html. Accessed December 17th, 2024.
Definition / general
- Classic myeloid antigen (also CD13)
Pathophysiology
- 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
- Gemtuzumab ozogamicin (anti-CD33 antibody), was previously used to treat AML (Wikipedia - Gemtuzumab ozogamicin, BioDrugs 2006;20:137, Cancer 2005;104:1442)
- Used for negative selection for stem cells
Uses by pathologists
- Distinguish myeloid (CD33+) and lymphoid leukemias (CD33-)
- Identify monocytes by flow cytometry
Positive staining - normal
- Progenitor and other myeloid cells (decreasing expression with maturation, Am J Pathol 2001;158:1473)
- Basophils, granulocytes (low level expression), mast cells (Am J Pathol 1996;149:1493), monocytes (most), NK cells, plasmacytoid dendritic cells, T cells (some, J Leukoc Biol 2006;79:46)
- Epidermal Langerhans cells (variable)
Positive staining - disease
- AML M0 (almost all, Am J Clin Pathol 2001;115:876), M1-M5 (75-85%), M7 (variable)
- ALK+ anaplastic large cell lymphoma (Am J Clin Pathol 2008;130:628), CML (90%), chronic myelomonocytic leukemia, myeloid / granulocytic sarcoma (J Clin Pathol 2005;58:325), transient myeloproliferative disorder (Am J Clin Pathol 2001;116:204)
- CD4+ CD56+ acute leukemias (Blood 2005;105:1256) and lineage negative malignancies (weak in 44%, Am J Surg Pathol 2005;29:1274)
- Myeloma and plasmacytoma (occasional reports)
- Burkitt’s lymphoma (J Clin Pathol 1993;46:778), SLL/CLL (Am J Clin Pathol 2003;119:824) or T-ALL (Am J Clin Pathol 2000;113:823)
- More intense in bone marrow than peripheral blood
Negative staining
- Pluripotent stem cells, B cells
- Most B and T cell lymphomas, blastic NK lymphoma (usually)
- Not expressed outside hematopoietic system
Additional references
