Spectrum of acute leukemias diagnosed on flow cytometry: Analysis from tertiary care centre from North India

BACKGROUND: Acute leukemias (ALs) are a heterogeneous group of malignancies with varying clinical, morphologic, immunologic, and molecular characteristics. WHO 2008 classification of ALs require a multi-parametric approach to the diagnosis. This study aims to evaluate the role of flow cytometry in diagnosis and sub-classification of acute leukemias. METHODS: Consecutive patients of adult and paediatric ALs during June 2012 to May 2013 were retrospectively analyzed and studied using BD FACS Canto-II flow cytometer. The results of immunophenotyping were reviewed and analyzed for cross-lineage antigen expression. RESULT: Over a period of year, 422 individuals were diagnosed as AL. There were 287 males and 135 females with M:F = 2.1:1. There were 237 adults & 185 children. 36.3% were AML and 60.4% were ALL, while 3.3% of cases were mixed phenotypic acute leukemia (MPAL). The commonest WHO subtype in AML group was AML with maturation being 31%. In case of ALL there were 83.9% B-ALLs and 16.1% T-ALLs. In MPAL B-Myeloid was 71.4%, whereas T-Myeloid was 28.6% of cases. Both AML and MPAL were more frequently seen in adults accounting to 83% and 92.9% respectively of all ALs cases. In contrast, 62% of ALLs were children and only 38% were adults. Out of all ALs, 37.6% of showed cross lineage antigen expression. In AML, B-ALL and T-ALL cross lineage antigen expression were 26.14%, 39.71% and 82.9% respectively. CONCLUSION: Flow cytometry is useful in diagnosis and sub classification of AL. It is essential in cytochemical myeloperoxidase (MPO) negative cases. Cross- lineage antigen expression is frequent in ALs, and hence, lineage specific intra-cytoplasmic antibodies including anti-MPO and cytoplasmic-CD3 are essential for correct categorization of ALs. DOI: http://dx.doi.org/10.3126/acclm.v1i1.12308 Ann. Clin. Chem. & Lab. Med. 1(1) 2015: 12-15