Background: Many cytogenetic changes and gene mutations are associated with acute myeloid leukaemia (AML) survival outcomes. CD56 is related to poor prognosis when expressed in adult AML. The prognostic value of CD56 in children with AML has rarely been reported. Procedure: To evaluate the prognostic value of CD56 in childhood AML, multicentric retrospective study included 224 paediatric patients in two hospitals between January 2015 and April 2021. Results: The median (range) age was 75 (8-176) months, and the median follow-up time was 31 months. There was no significant difference in the 3-year overall survival rate between the CD56-positive and CD56-negative groups (78.4% vs. 73.3%, P=0.496). For patients who received haematopoietic stem cell transplantation, there was no significant difference in the 3-year overall survival rate between the CD56-positive and CD56-negative groups (59% vs. 63.9%, P=0.922). Multivariate analysis showed that CD56 positivity was not an independent prognostic factor for childhood AML (hazard ratio 0.85, P=0.648). Furthermore, in children with AML, CD56 positivity was more likely to be associated with the CBFβ-MYH11 mutation and mixed lineage leukaemia gene rearrangement. Conclusions: In summary, we demonstrated that CD56 cannot be used as a factor to predict the prognosis of children with AML.

Objective: Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies showed that single nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. We investigated the associations between SNPs and haplotypes of interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL-10), interferon gamma (IFN-γ), IFN regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2) and susceptibility to EBV-HLH in children. Methods: 66 children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in the study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656, IL-10 rs1800896, rs1800871, and rs1800872, IFN-γ rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique. Results: The frequencies of the AA genotype and A allele of IL2RA rs2104286 and IL-10 rs1800896, and the CC genotype and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group compared with those in the control group, respectively. The frequencies of genotypes and alleles of IL2RA rs2104286, IL-10 rs1800871, IFN-γ rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. In addition, the IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL-10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also significantly more frequent in the EBV-HLH group. Conclusions: The SNPs of IL2RA rs2104286, IL-10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL-10 ACC are highly associated with susceptibility to EBV-HLH in children.