Proliferation patterns of peripheral blood lymphocytes in CLL patients: cytophotometric and microfluorimetric study.

Peripheral blood lymphocytes of 19 patients with CLL, 9 patient with LS and 10 healthy donors were studied by Feulgen cytophotometry, 3HTdR autoradiography, A0 microfluorimetry and PHA stimulated cultures. In CLL the bulk of cells are in G0 (80.6 +/- 3.7%) the rest are in G1 (16.3 +/- 3.6%) and S + G2 (3.0 +/- 1.0%). Thymidine LI values were two orders lower (0.098 +/- 0.04). In five cases combined autoradiographic and cytophotometric study on the same cells revealed 6-14% of cells arrested in S. In peripheral blood of LS patients G0 cells also predominate, and only in 3 cases cytophotometry revealed hyperdiploid (S + G2) cells. In normal lymphocytes 1.5 hrs after PHA stimulation A0 binding increases on the average by 80% compared to unstimulated cultures and remains at this level during 12 hrs. CLL and LS cells behave nearly the same with the only difference: the 80% increase is observed only after 3-4.5 hrs in culture. G0----G1 flow rate in case of normal lymphocytes is higher than for neoplastic cells but both are recruited into cell cycle during all the period in culture. G1----S transition is delayed in case of LS lymphocytes and strongly inhibited in CLL lymphocyte cultures compared to normal cells. The possible mechanisms of these features are discussed.