Myeloperoxidase-deficient polymorphonuclear leucocytes (VII): Incidence in untreated myeloproliferative disorders

In 98 patients with chronic myeloproliferative disorders (45 chr. myeloid leukaemia (CML), 19 myelofibrosis primaria (MP), 28 polycythaemia vera (PV) and 6 idiopathic thrombocythaemia (IT)) the incidences of increased numbers of MPO-deficient polymorphonuclear (PMN) were 60% in CML, 32% in MP, 7% in PV and 0% in IT patients. The CML figure differed significantly from the others (p less than 0.001). This study confirms the finding of low NAP scores in CML compared to normal or high NAP scores in the other groups of the myeloproliferative syndrome. The incidences of increased numbers of MPO-deficient PMN in this study are comparable to those found in the primary myelodysplastic syndromes and in acute myeloid leukaemia. The finding supports the view that some of the CML cases and may be other cases of the chronic myeloproliferative disorders may be fundamentally the same disease as in primary myelodysplastic syndromes and in acute myeloid leukaemias.