The use of the H*1 in predicting marrow recovery following ablative chemotherapy in leukaemia and lymphoma.

Twenty-three cytopenic episodes in 18 patients undergoing ablative chemotherapy for the treatment of leukaemia or lymphoma were monitored from commencement of treatment until recovery, by automated differential counts using the Technicon H*1 Autoanalyser, with particular reference to abnormal white cell flags and large unstained cell (LUC) percentage. The blast flag was indicated in this recovery phase in 100% of patients and in 85% this preceded bone marrow recovery (defined as neutrophil count greater than 0.5 X 10(9)/l) by a mean of 10 days. On average the blast flag was indicated for 8 days in total. Bone marrow function continued to improve in all patients with no evidence of relapse. An increase in the LUC percentage on the differential count reached a maximum at 18 days, 6 days prior to marrow recovery. The ability to detect impending marrow recovery by means of the positive blast flag, may be of great value when patients have been cytopenic for many days.