EXPRESSION OF THE IMMUNOGLOBULIN SUPERFAMILY CELL MEMBRANE ADHESION MOLECULE CD146 IN ACUTE LEUKEMIA

Background: The expression of the immunoglobulin superfamily cell membrane adhesion molecule CD146 has been reported on several normal and pathological cell types in human. The aim of this study was to investigate CD146 expression in acute leukemia using a multiparametric cytofluorimetric approach. Methods: Cytofluorimetric and cytogenetic studies were performed on peripheral blood and bone marrow samples from 162 patients with acute myeloid leukemia (AML, n=121) and acute lymphoblastic leukemia (ALL, n=41). ALL patients were subdivided in B-ALL (n=38) and T-ALL (n=3). Adult (n=18) and pediatric (n=20) B-ALL were considered as a whole group. Results: Four out of 121 (3.3%) AML cases, 14/38 (36.8%) B-ALL, and 2/3 (66.6%) T-ALL expressed CD146 on 12-98% of blasts (p< 0.001). CD146 expression was not observed in 10 healthy controls. Among B-ALL CD146-positive cases, 78.6% were associated with a "common"/BII-ALL and 21.4% with a pre-B/BIII-ALL immunophenotype while pro-B/BI-ALL and mature-B/BIV-ALL cases were CD146-negative. Statistical analysis showed CD146 expression strongly associated with Ph1 positivity in B-ALL with the highest percentage of CD146-positive blasts in all Ph-positive B-ALL cases (84 +/- 22% Ph-positive B-ALL SD vs. 40 +/- 24% SD in Ph-negative B-ALL; p< 0,001). Conclusion: In our series, CD146 was expressed in all cases of Ph-positive B-ALL and in the vast majority of T-ALL, whereas it was rarely expressed by AML blasts. We suggest that CD146 may be considered as an additional marker for acute lymphoblastic leukemia diagnosis and monitoring of minimal residual disease in those cases which are CD146-positive at diagnosis. (C) 2015 International Clinical Cytometry Society