Title: Leukocyte Alkaline Phosphatase (LAP/NAP score) in peripheral blood smear (human)
Description: Stain: Alkaline phosphatase staining (Ackerman).
In mature neutrophils granules contain alkaline phosphatase. In eosinophils no alkaline phosphatase activity is present.
A considerable number of brown stained neutrophils can be indicative for a patient with infection (leukemoid reaction, A).
Image in (B) is from a patient with CML (chronic myeloid leukaemia) showing an increased number of leucocytes without toxic granules, i.e. alkaline phosphatase-negative.
Cytochemical reactions in smears are useful for the differential diagnosis of certain diseases.
Keywords/Mesh: blood, bone marrow, alkaline leukocyte phosphatase, neutrophil, LAP score, leukemoid reaction, chronic myeloid leukemia, histology, POJA collection