Expression of aberrant CD markers in acute leukemia: a study of 100 cases with immunophenotyping by multiparameter flowcytometry.

BACKGROUND: Acute leukemia is a heterogenous disease having diverse phenotypes. Immunophenotyping by flowcytometry is essential for diagnosis of myeloid and lymphoid subtypes. Aberrant phenotype incidence is controversial and dissimilar results have been reported by different groups.

OBJECTIVES: Purpose of the study was to determine the incidence of aberrant phenotypes in North East Indian patients with acute leukemia.

METHODS: We analysed a total of 100 cases (AML = 36, ALL = 61, MPAL = 3) by multiparametric flow cytometry using an acute panel of monoclonal antibodies (MoAbs). The MoAbs were selected to identify differentiation-associated antigens of both myeloid and lymphoid lineages.

RESULTS: Aberrant phenotypes were found in 21 (58.3%) cases of AML, 36 (59.2%) cases of B-ALL and 6 (66.7%) cases of T-ALL. CD7 was the most frequent lymphoid associated antigen found in 33% of AML cases while CD117 was the myeloid antigen most frequently detected in ALL (54%) cases. Aberrant expression of CD 117 is highly significant by Fischer's exact test (P< 0.0001).

CONCLUSION: We conclude that aberrant phenotypes are present in a great majority of acute leukemia patients of North East India. Future studies will be directed to correlate of these markers with prognosis and therapeutic response.