Which combination of surface markers is most characteristic of precursor B-cell acute lymphoblastic leukemia?

Which combination of surface markers is most characteristic of precursor B-cell acute lymphoblastic leukemia?

• A. CD3+, CD7+
• B. CD10+, CD19+, CD22+
• C. CD16+, CD56+
• D. CD34+, CD45-

Answer: (B)

Precursor B-cell ALL is defined by markers that reveal immature B-lineage commitment. The hallmark is expression of CD19 and CD22, which are standard B-lineage markers on developing B cells. CD10, the common ALL antigen, is frequently present on these early B-cell blasts. Seeing a pattern of CD10 together with CD19 and CD22 strongly points to B-lineage precursors, which is exactly what precursor B-cell ALL is. In contrast, one alternative shows T-cell markers (CD3 and CD7), which would indicate T-lineage ALL rather than B-lineage. Another option has NK cell markers (CD16 and CD56), not characteristic of B-cell blasts. The last pattern includes CD34 with CD45-; while CD34 can be present in lymphoblasts, CD45- is not specifically characteristic of precursor B-cell blasts and does not define the B-lineage phenotype as clearly as CD19, CD22, and CD10 do.

Precursor B-cell ALL is defined by markers that reveal immature B-lineage commitment. The hallmark is expression of CD19 and CD22, which are standard B-lineage markers on developing B cells. CD10, the common ALL antigen, is frequently present on these early B-cell blasts. Seeing a pattern of CD10 together with CD19 and CD22 strongly points to B-lineage precursors, which is exactly what precursor B-cell ALL is.

In contrast, one alternative shows T-cell markers (CD3 and CD7), which would indicate T-lineage ALL rather than B-lineage. Another option has NK cell markers (CD16 and CD56), not characteristic of B-cell blasts. The last pattern includes CD34 with CD45-; while CD34 can be present in lymphoblasts, CD45- is not specifically characteristic of precursor B-cell blasts and does not define the B-lineage phenotype as clearly as CD19, CD22, and CD10 do.