Incidence of lymphoid markers in acute myeloid leukemia. Alkaline phosphatase-antialkaline phosphatase versus immunofluorescence.

The aim of the present study was to compare the immunofluorescence technique (IF) with the immunoenzymatic (IE) alkaline phosphatase-antialkaline phosphatase method for the evaluation of the presence of lymphoid antigens (Ag) in 46 cases of acute myeloid leukemia (AML). The first technique allows detection of Ag expressed on the cytoplasmic membrane of living cells, whilst the second shows the presence of intracytoplasmic Ag on fixed cells. In general, the percentages of lymphoid Ag expression on AML cells are relatively low with both IE (15.2%) and IF (17.4%). We found a good correlation between the two methods for CD2 (4/4), CD7 (4/5), CD20 (1/1) and CD4 (2/2). The Ag CD19, CD21 and CD8 were negative in all cases, both with IE and with IF. CD3 (2 cases) and CD22 (1 case) were only evident with IE. CD10 was seen in 1 case with IF, whilst it was found more frequently with IE. For this reason, demonstration of CD10 with IF is more specific for the classification of acute leukemia.