Evaluation of complete disease remission in acute myeloid leukemia - A prospective study based on cytomorphology, interphase fluorescence in situ hybridization, and immunophenotyping during follow-up in patients with acute myeloid leukemia

BACKGROUND. Different diagnostic methods add information to define complete remission (CR) in patients with acute myeloid leukemia (AML). The detection of minimal residual disease (MRD) for predicting prognosis and for therapeutic planning still are under discussion. METHODS. The authors studied 216 patients with AML at the time of initial diagnosis and during follow-up and correlated cytomorphology, interphase fluorescence in Situ hybridization (FISH), and flow cytometry results to evaluate response status. They further tested the prognostic impact of those results, especially in patients who achieved a morphologic CR. RESULTS. Interphase FISH was found to be correlated significantly with the clinical course at the time of complete cytomorphologic remission and was more reliable than morphology for defining CR. Furthermore, interphase FISH was correlated with immunophenotyping results at all times during follow-up. CONCLUSIONS. The Current results indicated that interphase FISH may be used as a valid MRD parameter in patients with AML. Multiparameter immunophenotyping for MRD also was correlated strongly with the clinical Course, and the authors suggest integrating such immunophenotyping into the routine diagnostic panel at the time of diagnosis and during the clinical course in patients with AML.