Immunophenotyping of leukaemias by flow cytometry and APAAP: a two-year comparative analysis in hospital practice.

Using a panel of monoclonal antibodies for the immunophenotyping of haematological malignancies, we have made a direct comparison of the usefulness of indirect immunofluorescence using flow cytometry (IFC) alongside the alkaline phosphatase-anti-alkaline phosphatase (APAAP) immunoenzyme method. Analysis of 400 consecutive patient samples (blood and bone marrow) over a 2-year period, resulted in unequivocal phenotyping agreement by both methods in 98 per cent of cases. The positive results accounting for 2 per cent discordance were obtained by the APAAP method. The value of the technique in the clinical management of patients with leukaemia is documented together with guidelines for clinical laboratories.