Myeloperoxidase deficient polymorphonuclear leucocytes: computerized planimetric estimations of cellular and nuclear size.

Quantitative estimations of the mean areas of cell, nucleus and cytoplasm in polymorphonuclear leucocytes (PMN) were performed by automated image analysis of blood smears from six patients with acute myeloid leukaemia. The PMN were qualitatively separated by a cytochemical staining method into two well-defined subpopulations i.e. myeloperoxidase (MPO)-normal and MPO-deficient PMN. MPO-deficient PMN were characterized by a decreased size of the total cell (P less than 0.01), an increased size of the nucleus (P less than 0.01) and a decreased size of the cytoplasm (P less than 0.01). The resulting highly increased nucleus-to-cytoplasm ratio in this specific PMN subpopulation bears a striking resemblance to cells in malignant tumours. The planimetric results in this study further support the concept that MPO-deficient PMN may be the progeny of leukaemic precursors.