Flow Cytometry and Cellular Markers

Question 1

CD3

Answer 1

Most specific T cell Ag, stains Th/Tc/NKT

Question 2

CD4

Answer 2

Th cells, normally at a higher percentage than Tc cells, although this is reversed in HIV patients

Question 3

CD5

Answer 3

Unique to CLL B cells, otherwise only on T cells

Question 4

CD7

Answer 4

Found on T-cells, used as a marker for mycosis fungoides (Sézary Syndrome)

Question 5

CD8

Answer 5

Tc cell marker

Question 6

CD10

Answer 6

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

Question 7

CD11c

Answer 7

Marker for M4/5, and Hairy Cell Leukemia

Question 8

CD13

Answer 8

Myeloid Ag, associated with AML diagnosis (M1-6) and CML

Question 9

CD14

Answer 9

Monocyte differentiation Ag

Question 10

CD16a

Answer 10

Binds Fc portion of IgG, markers NK cells and Macrophages

Question 11

CD19

Answer 11

Earliest B cell Ag, more sensitive to detecting ALLs than CD20

Question 12

CD20

Answer 12

Appears between CD19/10 and CD21/22 on B cells, used for more mature B cell lymphomas

Question 13

CD22

Answer 13

Pan B cell marker

Question 14

CD23

Answer 14

Promotes B cell differentiation to Plasma cells, differentiates CLL/SLL

Question 15

CD25

Answer 15

Regulatory T cell marker, associated with advanced T cell cutaneous lymphoma

Question 16

CD33

Answer 16

Classic Myeloid Ag in AMLs and CMLs

Question 17

CD34

Answer 17

Marker for stem cells (blasts), in ALLs and AMLs

Question 18

CD38

Answer 18

Plasma cell marker

Question 19

CD45

Answer 19

Pan leukocyte Ag

Question 20

CD56

Answer 20

NK cell marker

Question 21

CD117

Answer 21

Stem cell marker

Question 22

CD2

Answer 22

Early T marker Can indicate T-ALL

Question 23

Naive T cells

Answer 23

Express L-selectin and lack CD25, CD44, and CD69 Gain these markers plus CD62 when activated

Question 24

MHC Class I

Answer 24

Intercellular Ag presentation, only recognized by Tc cells (CD8) that kill the cells to which they bind

Question 25

MHC Class II

Answer 25

Present extracellular Ag, and only bind to Th (CD4) cells

Question 26

Sarcoidosis

Answer 26

Tiny clumps of inflammatory cells (granulomas) triggered by Th lymphocytes causing lumps to form on skin and potentially in lungs

Question 27

Markers tested by Flow Cytometry

Answer 27

1. Leukocyte markers 2. Myeloperoxidase 3. T-helper cells, T suppressor cells 4. T-cells, B-cells, NK cells 5. Terminal Deoxynucleotidyl Transferase (TDT)

Question 28

AML Markers

Answer 28

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

Question 29

AML-M3

Answer 29

Characterized by lacking HLA-DR while expressing the other AML markers

Question 30

AML-M4/M5

Answer 30

Show simultaneous expression of CD14 and CD64

Question 31

B-cell ALL

Answer 31

CD22 with CD19 and HLA-DR CD22 can appear dimly in AML, so the simultaneous expression of all 3 is required

Question 32

T-cell ALL

Answer 32

CD3 with CD7 Subtypes can be defined by the following markers: CD1a, CD2, CD3, CD4, CD8

Question 33

B-cell Non-Hodgkin Lymphoma

Answer 33

Clonal expression of kappa/lambda light chains with expression of pan B cell Ag (CD19)

Question 34

Plasmocytoma

Answer 34

CD38 (or CD138) without B cell specific Ag or surface Ig

Question 35

Hairy Cell Leukemia

Answer 35

High forward scatter, CD11c and CD103

Question 36

B-cell CLL

Answer 36

CD19, CD20, CD5, CD23, CD22 and low surface Ig levels combine to indicate CLL Lack CALLA (CD10)

Question 37

Interpreting Flow Cytometry Data

Answer 37

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

Question 38

T-cell CLL

Answer 38

CD3 (pan T-cell), CD4 (Th)

Question 39

NKT Cells

Answer 39

CD2, CD16, CD56 while lacking CD3 and CD4

Question 40

Sézary Syndrome

Answer 40

Th cells lack CD7

Question 41

Differentiating Young and Mature B cells

Answer 41

CD19 marks all B cells and appears before CD10, CD20 (doesn't appear on young B cells), CD22, CD23