Cytophotometry of granulocytes in chronic granulocytic leukemia patients. Part I. Cell cycle distribution, S-phase transition and quantitative cytochemistry.

In the chronic phase of CGL the proportion of granulocytes in S + G2 was lower (18.7 +/- 1.3% in marrow and 16.7 +/- 2.4% in blood) than in normal bone marrow (42.4 +/- 2.9%) as studied by Feulgen-DNA cytophotometry. During the blast crisis the percentage of S + G2 blasts was 39.3 +/- 8.4 in marrow and 38.7 +/- 7.8 in blood which was much higher than in acute myeloblastic leukemia patients (10.8 +/- 1.4 and 5.1 +/- 1.0). Thymidine labelling index values were lower than the percentage of cytophotometrically detected S-phase cells: up to 28% of cells with Feulgen-DNA content corresponding to S-phase did not incorporate 3H-thymidine. The rate of DNA synthesis remained constant during the S-phase but 3H-thymidine uptake increases towards the end of the S-phase. Morphometric parameters and quantitative cytochemical (PAS, Sudan, myeloperoxidase activity) characteristics of polymorphonuclear neutrophils were altered during the chronic phase of the disease but remained in the normal range during the blast crisis. Mature neutrophils in the blast crisis are assumed to originate from normal granulocyte progenitors.