Automated leucocyte differential counts in acute leukaemia: a comparison of the Hemalog D, H6000 and Coulter S-plus IV.

The automated peripheral blood differential counts produced by the Hemalog D, H6000 and Coulter S-plus IV were analysed in 32 cases of acute leukaemia (22 AML (acute myeloblastic leukaemia); 10 ALL (acute lymphoblastic leukaemia], all with greater than 30% circulating blast cells. All three machines were highly effective in recognizing the presence of an abnormality. With the Hemalog D and H6000, the presence of increased LUC and HPX cells, together with an LPX alarm, was suggestive of acute leukaemia. With the Coulter S-plus IV, multiple alarms indicated the need for further investigation but, since alarms occur in many other situations, their presence was not necessarily suggestive of acute leukaemia. All the machines were of value in distinguishing AML from ALL since 'lymphocytes' were predominant in all cases of ALL and 'neutrophils' the majority cell type in most patients with AML. However, the presence in a minority of cases of AML of large numbers of micromyeloblasts recognized as 'lymphocytes' limited the discriminating power of all three machines. The Hemalog D allowed some definition of subtypes of AML, but the H6000 and Coulter S-plus IV were of no value in this regard.