The relevance of cytological studies and Ki-67 reactivity to the clinical course of chronic lymphocytic leukemia.

The aim of the study was to investigate whether the growth fraction and cytology of peripheral blood and lymphoid tissues relate to response to treatment in CLL. Growth fraction was assessed using the monoclonal antibody Ki-67. Peripheral blood (PB) films and lymph node and spleen touch imprints or aspirates were examined in 35 patients (pts) with CLL: smouldering CLL (4 pts) (no therapy), progressive CLL but responsive to chlorambucil and cyclophosphamide (15 pts) and resistant CLL (16 pts). Cytological studies of lymphoid tissues showed that pts with resistant CLL had an increased proportion of prolymphocytes and blasts and the highest Ki-67 expression (mean 6,6%). PB morphology was not different between the groups of resistant and responsive CLL. However, the cases with resistant CLL showed a higher percentage of Ki-67 positive PB cells (p<0,05). Four pts with indolent CLL had typical CLL morphology in the PB and the lowest numbers of prolymphocytes and blasts with Ki-67 positive cells in lymphoid tissues.