Deciphering the Significance of CD56 Expression in Pediatric Acute Myeloid Leukemia: A Report from the Children’s Oncology Group

Pardo LM, Voigt AP, Alonzo TA, Wilson ER, Gerbing RB, Paine DJ, Dai F, Menssen AJ, Raimondi SC, Hirsch BA, Gamis AS, Meshinchi S, Wells DA, Brodersen LE, Loken MR. Deciphering the Significance of CD56 Expression in Pediatric Acute Myeloid Leukemia: A Report from the Children’s Oncology Group. Cytometry B Clin Cytom. 2020 Jan;98(1):52-56. doi: 10.1002/cyto.b.21829. Epub 2019 Jul 11. PubMed PMID: 31294507; PubMed Central PMCID: PMC7872511.

In patients with acute myeloid leukemia (AML), CD56 expression has been associated with adverse clinical outcome. We reported on a phenotype associated with very poor prognosis (RAM) in children enrolled in the Children’s Oncology Group trial AAML0531 (3). RAM is also characterized in part by high-intensity expression of the CD56 antigen. Herein, we investigate underlying biological and clinical differences among CD56-positive AMLs for patients in AAML0531. For 769 newly diagnosed pediatric patients with de novo AML enrolled in AAML0531, bone marrow specimens were submitted for flow cytometric analysis. For each patient, an immunophenotypic expression profile (IEP) was defined by mean fluorescent intensities of assayed surface antigens. Unsupervised hierarchical clustering (HCA) was completed to group patients with similar immunophenotypes. Clusters were then evaluated for CD56 expression. Principal component analysis (PCA) was subsequently applied to determine whether CD56-positive patient groups were non-overlapping.