Cellular renewal kinetics of malignant non-Hodgkin's lymphomas.

Although the DNA synthesis times of the dividing NHL cell types were found to be within the normal range (7--12 h), the generation times of these neoplastic lymphocytes seem to be prolonged. However, even with a normal percentage of proliferating lymphoma cells (=growth fraction), the total number of mitotically active neoplastic lymphocytes is considerably increased in each NHL due to extensive enlargement of the total cellularity of each patient's lymphatic system. Therefore, in each NHL patient, the total cellularity of each patients' lymphatic system. Therefore, in each NHL patient, the total number of newly produced lymphoma cells is significantly increased. According to the Kiel classification of the NHL, the NHL of low-grade malignancy are considered to be characterized by the proliferative constellation of an enhanced cell production associated with reduced or normal cell death rates, whereas in the NHL of high-grade malignancy, increased cell death rates seem to be overcompensated by even higher cell renewal rates. These differences in the cellular proliferation kinetics of the NHL are supposed to be of higher prognostic and clinical significance than their B- or T-cell properties.