Cell kinetics in chronic lymphocytic leukaemia (CLL).

The fractional production rate of CLL lymphocytes, certainly in the peripheral blood and possibly in the lymph nodes, is often lower than normal. On the other hand, the absolute production in CLL blood and in lymph nodes seems to be considerably increased in most cases. Arguments for an increased lymphocyte life span in CLL, although fragmentary and dispersed, exist. The blood CLL lymphocytes, as normal lymphocytes, exchange rapidly with an extravascular pool of lymphocytes. However, recirculation of lymphocytes--from blood to blood via the lymph node and the thoracic duct--does not proceed normally in CLL. Whether this is related to the B nature of the CLL lymphocyte, to the leukaemic nature of the CLL lymphocyte or to mechanical factors--crowding of the extravascular pool--is still debatable.