Rapid immunocytochemical analysis of acute leukemias

Immunophenotypic analysis of acute leukemias is time consuming and often requires flow cytometric analysis. A 1-hour alkaline phosphatase-labeled streptavidin-biotin immunocytochemical procedure was evaluated as an alternative. Seventeen cases of acute leukemia, including 10 acute lymphocytic (ALL) and 7 acute nonlymphocytic, were phenotyped by the rapid immunocytochemical procedure and the results were compared with standard analyses. In all 17 cases, the diagnoses made using standard cytochemical and immunologic methods were the same as obtained in blinded reviews by rapid immunocytochemical analysis. Nine cases of precursor B-cell ALL were positive for CD19 and/or CD22. Five CD19 + cases of ALL reacted with anti-myeloperoxidase, with one case also positive for CD15. CD15 positivity was confirmed on repeated study as well as with plastic section immunoperoxidase staining. Nine cases of ALL were positive for CD10 and eight were positive for terminal deoxynucleotidyl transferase. One case of ALL marked as T-cell ALL with CD1, CD2, CD3, and CD7. All cases of acute nonlymphocytic leukemia were positive for CD15, CD13, and/or CD33; anti-myeloperoxidase was positive in all but one case of monocytic leukemia. All cases of acute nonlymphocytic leukemia were negative for CD10 and one was positive for terminal deoxynucleotidyl transferase. Acute leukemias apparently may be phenotyped easily and accurately in 1 hour with this immunocytochemical technique, and slides may be stored permanently for review. There was in these 17 cases high correlation of the diagnoses with standard flow cytometric and cytochemical results. This rapid method allows a coordinated evaluation of morphologic features and immunophenotype; the latter features facilitated confirmation of unexpected reactivity of myeloid markers CD15 and MPO-7 in some cases of ALL.