Adverse prognostic impact of CD36 and CD2 expression in adult de novo acute myeloid leukemia patients.

Abstract Background and objectives: A consecutive series of acute myeloid leukemias (AML) patients was analyzed in conditions which reduce the inter-assay variations (the same flow cytometer, the same observers and the same panel of monoclonal antibodies) in order to investigate the prognostic information provided by flow cytometry. Design and methods: Two hundred and sixty-six bone marrow (BM) samples from 326 patients enrolled in the LMA-99 protocol from the CETLAM group were studied by multiparametric flow cytometry. Immunophenotyping studies were performed on erythrocyte-lysed BM samples. Antigen expression of leukemic cells was analyzed using triple stainings with fluorochrome-conjugated combinations of monoclonal antibodies. Results: CD2 was positive in 21 cases (8%); an associated inv(16) was detected in eight CD2+ cases (38%). Two-year overall survival (OS) rate for CD2+/inv(16)+ patients was 75%, whereas it was 0% for CD2+/inv(16)− patients and 47% for CD2− patients ( p  = 0.0001). CD36 was expressed in 37% of patients ( n  = 98). Two-year leukemia-free survival (LFS) rate was 34% for CD36+ patients and 55% for CD36− patients ( p  = 0.001). In the multivariate analysis, CD2+ (RR = 8.4; p  = 0.0001) and adverse karyotype (RR = 10.2; p  = 0.0001) were associated with a lower CR rate, CD36+ (RR = 1.5; p  = 0.03), CD2+ (RR = 2; p  = 0.04) and adverse karyotype (RR = 4; p  = 0.0001) were associated with a lower OS and CD36+ (RR = 2; p  = 0.002) and adverse karyotype (RR = 3.5; p  = 0.005) predicted a lower LFS. Conclusions: CD2+ patients had a very poor OS when CD2/inv(16)+ cases were excluded. CD36 and CD2 expression at diagnosis can provide prognostically important information in adult de novo AML.