A Quantitative Assessment of Neutrophil Marrow in Seven Patients with Chronic Granulocytic Leukaemia

Abstract

Neutrophil marrow cellularity was determined in 7 patients with chronic granulocytic leukemia (CGL). The size of the mitotic pool (promyelocytes and myelocytes) and the number of metamyelocytes and bands and of segmented neutrophils in the postmitotic pool were determined from measurements of neutrophil-erythroid ratios in marrow biopsy sections and ferrokinetic estimates of marrow normoblasts. A section mitotic index was calculated in each patient from the numbers of mitotic figures and mitotic pool cells counted on marrow sections. Basal values previously established in normal subjects for the mitotic pool, for metamyelocytes and bands, and for segmented neutrophils, were 2.11 .+-. 0.36 .times. 109 cells/kg, 33 .+-. 0.61 .times. 109 cells/kg and 2.26 .+-. 0.42 .times. 109 cells/kg, respectively. The basal section mitotic index was 0.07 .+-. 0.01. In 7 patients with CGL the mitotic pool comprised 3.71-25.70 .times. 109 cells/kg, metamyelocytes and bands 7.70-51.01 .times. 109 cells/kg, and segmented neutrophils 3.45-28.81 .times. 109 cells/kg. Mitotic indices ranged from 0.04-0.10. No relationship was found between marrow cellularity and blood neutrophil count. A negative correlation existed between marrow cellularity and blood neutrophil count. A negative correlation existed between mitotic pool cellularity and mitotic index (r [correlation coefficient] = -0.76, n = 7 pairs). The results provide quantitative affirmation of neutrophil marrow hyperplasia and of increased neutrophil production by the marrow in CGL.