The Significance Of Clinical Examinations And Flow Cytometric Immunophenotyping In The Early Diagnosis Of De Novo Aggressive Natural Killer Cell Leukemia(ANKL)

Objective: Aggressive natural killer cell leukemia(ANKL) is a fatal hematological neoplasm characterized by a fulminating clinical course and extremely high mortality. Current diagnosis of this disease is not effective during the early stages and it is easily misdiagnosed as other NK cell disorders.Methods: We retrospectively analyzed the clinical characteristics and flow cytometric immunophenotype of 49 ANKL patients. Patients with extranodal NK/T cell lymphoma, nasal type(ENKTL) and chronic lymphoproliferative disorder of NK cell(CLPD-NK), who were diagnosed during the same time were used as comparisons.Results: Abnormal NK cells in ANKL were found to have a distinctive immunophenotype with CD56 bright CD16dim and markedly increased Ki-67 expression, whereas CD57 negativity and reduced expression of killer immunoglobulin-like receptor(KIR), CD161, CD7, CD8 and perforin were exhibited compared with other NK cell proliferative disorders(p<0.05). The positive rates of flow cytometry detection(95.9%) was higher than the rates for cytomorphological(81.6%), immunohistochemical(90%), cytogenetic(56.5%) and F-18 fluorodeoxyglucose positron emission tomography/computer tomography(18-FDG-PET/CT) examinations(50%)(p<0.05).Conclusion: ANKL is a highly aggressive leukemia with high mortality. Flow cytometry detection is sensitive for the early and differential diagnosis of ANKL with high specificity.