Flow Cytometry and Cellular Markers Flashcards
CD3
Most specific T cell Ag, stains Th/Tc/NKT
CD4
Th cells, normally at a higher percentage than Tc cells, although this is reversed in HIV patients
CD5
Unique to CLL B cells, otherwise only on T cells
CD7
Found on T-cells, used as a marker for mycosis fungoides (Sézary Syndrome)
CD8
Tc cell marker
CD10
CALLA Found on young B cells, used to aid diagnoses of: ALL, Angioimmunoblastic T cell lymphoma, Burkitt’s lymphoma, Diffuse large cell lymphoma, and follicular lymphoma
CD11c
Marker for M4/5, and Hairy Cell Leukemia
CD13
Myeloid Ag, associated with AML diagnosis (M1-6) and CML
CD14
Monocyte differentiation Ag
CD16a
Binds Fc portion of IgG, markers NK cells and Macrophages
CD19
Earliest B cell Ag, more sensitive to detecting ALLs than CD20
CD20
Appears between CD19/10 and CD21/22 on B cells, used for more mature B cell lymphomas
CD22
Pan B cell marker
CD23
Promotes B cell differentiation to Plasma cells, differentiates CLL/SLL
CD25
Regulatory T cell marker, associated with advanced T cell cutaneous lymphoma
CD33
Classic Myeloid Ag in AMLs and CMLs
CD34
Marker for stem cells (blasts), in ALLs and AMLs
CD38
Plasma cell marker
CD45
Pan leukocyte Ag
CD56
NK cell marker
CD117
Stem cell marker
CD2
Early T marker Can indicate T-ALL
Naive T cells
Express L-selectin and lack CD25, CD44, and CD69 Gain these markers plus CD62 when activated
MHC Class I
Intercellular Ag presentation, only recognized by Tc cells (CD8) that kill the cells to which they bind
MHC Class II
Present extracellular Ag, and only bind to Th (CD4) cells
Sarcoidosis
Tiny clumps of inflammatory cells (granulomas) triggered by Th lymphocytes causing lumps to form on skin and potentially in lungs
Markers tested by Flow Cytometry
- Leukocyte markers
- Myeloperoxidase
- T-helper cells, T suppressor cells
- T-cells, B-cells, NK cells
- Terminal Deoxynucleotidyl Transferase (TDT)
AML Markers
MPO, CD13, CD33 should be present without Lymphoid markers, excluding CD7 and TdT
CD34 and CD7 are associated with immature cells rather than cell lineage
AML-M3
Characterized by lacking HLA-DR while expressing the other AML markers
AML-M4/M5
Show simultaneous expression of CD14 and CD64
B-cell ALL
CD22 with CD19 and HLA-DR CD22 can appear dimly in AML, so the simultaneous expression of all 3 is required
T-cell ALL
CD3 with CD7 Subtypes can be defined by the following markers: CD1a, CD2, CD3, CD4, CD8
B-cell Non-Hodgkin Lymphoma
Clonal expression of kappa/lambda light chains with expression of pan B cell Ag (CD19)
Plasmocytoma
CD38 (or CD138) without B cell specific Ag or surface Ig
Hairy Cell Leukemia
High forward scatter, CD11c and CD103
B-cell CLL
CD19, CD20, CD5, CD23, CD22 and low surface Ig levels combine to indicate CLL Lack CALLA (CD10)
Interpreting Flow Cytometry Data
Ag expression should be analyzed without selecting analysis regions in case the dot plot goes off the scale Dividing them later based on light scatter with different dyes allows the data to be interpreted more easily
T-cell CLL
CD3 (pan T-cell), CD4 (Th)
NKT Cells
CD2, CD16, CD56 while lacking CD3 and CD4
Sézary Syndrome
Th cells lack CD7
Differentiating Young and Mature B cells
CD19 marks all B cells and appears before CD10, CD20 (doesn’t appear on young B cells), CD22, CD23
