Role of Immunophenotyping in Myeloperoxidase Negative Acute Leukemias

INTRODUCTION Inspite of the advances in cytochemistry , accurate diagnosis before the onset of specific therapy has been a difficult domain in the field of leukemias. The present study is designed to establish the role of immunophenotyping by flowcytometry in diagnosis of acute leukemias. MATERIAL & METHODS- -50 cases of acute leukemias were studied from Dec2009 to Aug2011 in SCB Medical College .All  cases of APML and clearly myeloid cases with prominent auer rods and strong MPO positivity were excluded from the study. Morphology, cytochemistry and immunophenotypicprofiles(using multiparameter BD FACS Caliber)of the cases were evaluated and compared. OBSERVATION Out of 50 cases, 24(48%)cases were of pre-B ALL, 15(30%) cases of pre-T-ALL and 11(22%)cases were of AML. In addition ,immunophenotyping corrected the lineage from ALL to AML in 3(6%) cases. Out of 24 cases of pre-B ALL,11(45%) showed aberrant myeloid antigen expression and 2 cases were CD10 negative.8 cases of pre -T-ALL showed aberrant myeloid antigen expression. CONCLUSION The study highlights the pivotal role played by immunophenotyping of acute leukemias in specificlineage determination before the onset of therapy.