A higher CD34 + cell dose correlates with better event-free survival after KIR-ligand mismatched cord blood transplantation for childhood acute myeloid leukemia

J Hematol Oncol. 2024 Apr 29;17(1):24. doi: 10.1186/s13045-024-01548-3.

Abstract

Although killer Ig-like receptor ligands (KIR-L) mismatch has been associated with alloreactive natural killer cell activity and potent graft-versus-leukemia (GVL) effect among adults with acute myeloid leukemia (AML), its role among children with AML receiving cord blood transplantation (CBT) has not been determined. We conducted a retrospective study using a nationwide registry of the Japanese Society for Transplantation and Cellular Therapy. Patients who were diagnosed with de novo non-M3 AML and who underwent their first CBT in remission between 2000 and 2021 at under 16 years old were included. A total of 299 patients were included; 238 patients were in the KIR-L match group, and 61 patients were in the KIR-L mismatch group. The cumulative incidence rates of neutrophil recovery, platelet engraftment, and acute/chronic graft-versus-host disease did not differ significantly between the groups. The 5-year event-free survival (EFS) rate was 69.8% in the KIR-L match group and 74.0% in the KIR-L mismatch group (p = 0.490). Stratification by CD34 + cell dose into four groups revealed a significant correlation between CD34 + cell dose and EFS in the KIR-L mismatch group (p = 0.006) but not in the KIR-L match group (p = 0.325). According to our multivariate analysis, KIR-L mismatch with a high CD34 + cell dose (≥ median dose) was identified as an independent favorable prognostic factor for EFS (hazard ratio = 0.19, p = 0.029) and for the cumulative incidence of relapse (hazard ratio = 0.09, p = 0.021). Our results suggested that higher CD34 + cell doses are crucial for achieving a potent GVL effect in the context of KIR-L-mismatched CBT.

Keywords: Acute myeloid leukemia; Children; Cord blood cell transplantation; KIR-ligand.

Publication types

  • Research Support, Non-U.S. Gov't
  • Letter

MeSH terms

  • Adolescent
  • Antigens, CD34*
  • Child
  • Child, Preschool
  • Cord Blood Stem Cell Transplantation*
  • Female
  • Graft vs Host Disease / etiology
  • Humans
  • Infant
  • Leukemia, Myeloid, Acute* / mortality
  • Leukemia, Myeloid, Acute* / therapy
  • Male
  • Receptors, KIR*
  • Retrospective Studies