Neutrophil 5-nucleotidase reaction in chronic myelogenous leukemia, myelofibrosis with myeloid metaplasia, and polycythemia vera.

A readable and reproducible 5-nucleotidase (5N) cytochemical reaction was developed for blood smear preparation, after modification of the technique of Wachstein and Meisel. The reaction was applied to normal polymorphonuclear neutrophils (NPN) and to neutrophils from patients with chronic myelogenous leukemia (CML), myelofibrosis with myeloid metaplasia (MMM), and polycythemia vera (PV). The following observations were made: (a) 5N was present in NPN, with a mean score of 83.2+/-15.7. (b) In patients with MMM and PV an increased 5N score was observed (mean score 111+/-63.8 and 178.3+/-83.3, respectively). (c) In CML the mean score was 4.9+/-2.2. (c) A statistical comparison of neutrophil 5-nucleotidase (N5N) between CML and MMM and PV patients demonstrated a highly significant difference (p<0.0001). In the present study, we showed that the N5N activity parallels that of NAP in chronic myeloproliferative disorders such as CML, MMM, and PV. It appears that, apart from the already known activity of NAP in myeloproliferative disorders, other enzymes (e.g., N5N) can present a similar behavior with increased or decreased activity.