Which LAP score is typical for chronic myeloid leukemia (CML)?

Which LAP score is typical for chronic myeloid leukemia (CML)?

• A. Decreased
• B. Increased
• C. Normal
• D. Variable

Answer: (B)

LAP score measures how active neutrophils are by their leukocyte alkaline phosphatase content. In chronic myeloid leukemia, the neutrophils (part of the malignant clone) have reduced enzyme activity, so the LAP score is typically decreased. This helps distinguish CML from a leukemoid reaction, where neutrophils are highly activated and the LAP score is elevated. A normal or highly variable LAP is less characteristic of CML. Therefore, the typical LAP score for CML is decreased.

LAP score measures how active neutrophils are by their leukocyte alkaline phosphatase content. In chronic myeloid leukemia, the neutrophils (part of the malignant clone) have reduced enzyme activity, so the LAP score is typically decreased. This helps distinguish CML from a leukemoid reaction, where neutrophils are highly activated and the LAP score is elevated. A normal or highly variable LAP is less characteristic of CML. Therefore, the typical LAP score for CML is decreased.