Leucocyte alkaline phosphatase (LAP) is raised in all conditions except:
Low LAP scores have been associated with CML, PNH, thrombocytopenic purpura, and hereditary hypophosphatasia. In CML regardless of the total white count, the score remains low.
Myelofibrosis
Essential thrombocythemia
Chronic myeloid leukaemia
Polycythemia
Chronic Myelogenous Leukemia