IL-10-592 A/C polymorphisms is associated with EBV-HLH in Chinese children

Genetics of Acquired Cytokine Storm Syndromes : Secondary HLH Genetics

Secondary hemophagocytic lymphohistiocytosis (sHLH) has historically been defined as a cytokine storm syndrome (CSS) occurring in the setting of triggers leading to strong and dysregulated immunological activation, without known genetic predilection. However, recent studies have suggested that existing underlying genetic factors may synergize with particular diseases and/or environmental triggers (including infection, autoimmune/autoinflammatory disorder, certain biologic therapies, or malignant transformation), leading to sHLH. With the recent advances in genetic testing technology, more patients are examined for genetic variations in primary HLH (pHLH)-associated genes, including through whole exome and whole genome sequencing. This expanding genetic and genomic evidence has revealed HLH as a more complex phenomenon, resulting from specific immune challenges in patients with a susceptible genetic background. Rather than a simple, binary definition of pHLH and sHLH, HLH represents a spectrum of diseases, from a severe complication of common infections (EBV, influenza) to early onset familial diseases that can only be cured by transplantation.

Polymorphisms and haplotypes of IL2RA, IL10, IFNG, IRF5, and CCR2 are associated with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

OBJECTIVE

Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies have shown that single-nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. As such, we investigated the association between susceptibility to EBV-HLH in children and SNPs and haplotypes of genes encoding interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL10), interferon gamma (IFNG), interferon regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2).

METHODS

Sixty-six children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in this study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656; IL10 rs1800896, rs1800871, and rs1800872; IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique.

RESULTS

Frequencies of the A allele of IL2RA rs2104286 and IL10 rs1800896, and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group than in the control group. The AA genotype of IL2RA rs2104286 and IL10 rs1800896, and the CC genotype of IL10 rs1800872 might be associated with a significantly high risk of EBV-HLH. However, the frequencies of genotypes and alleles of IL2RA rs2104286, IL10 rs1800871, IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. Additionally, IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also associated with an increased risk of EBV-HLH.

CONCLUSIONS

SNPs of IL2RA rs2104286, IL10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL10 ACC were highly associated with susceptibility to EBV-HLH in children.

[Association of interleukin-10 gene polymorphism with enterovirus 71 infection in children]

OBJECTIVE

To study the association of interleukin-10 (IL-10) -1082A/G, -819C/T, and -592C/A polymorphisms with IL-10 level and the severity of enterovirus 71 (EV71) infection in children.

METHODS

A total of 137 children with hand-foot-mouth disease due to EV71 infection were enrolled as EV71 infection group, which was further divided into mild group with 91 children and severe group with 46 children, and 122 healthy children who underwent physical examination were enrolled as healthy control group. Related clinical data were collected. ELISA was used to measure the serum level of IL-10, and polymerase chain reaction-restriction fragment length polymorphism was used to analyze IL-10 -1082A/G, -819C/T and -592C/A polymorphisms.

RESULTS

Compared with the healthy control group, the children with EV71 infection had significantly higher frequency of -1082 AA genotype and A allele (P<0.05). Among the children with EV71 infection, the severe group had significantly higher frequency of -1082 AA genotype and A allele than the mild group (P<0.05), while there was no significant difference in the distribution of IL-10 -819C/T and IL-10 -592C/A polymorphisms between the two groups (P>0.05). The severe group had a significantly higher serum level of IL-10 than the mild group and the healthy control group. IL-10 -1082 AA genotype, -819 TT genotype, and -592 AA genotype were associated with the low expression of IL-10 (P<0.05). As for haplotype, the EV71 infection group had a significantly lower frequency of GCC haplotype than the healthy control group (P<0.05). In the severe group, the children with ATA haplotype had a significantly lower IL-10 level than those with other haplotypes, and the children with GCC haplotype had a significantly higher IL-10 level than those with other haplotypes (P<0.05). There was no significant difference in IL-10 level between children with different haplotypes in the mild group and the healthy control group (P>0.05).

CONCLUSIONS

IL-10 gene polymorphisms are associated with IL-10 expression and the severity of EV71 infection in children.

IL-10-592 polymorphism is associated with IL-10 expression and severity of enterovirus 71 infection in chinese children

BACKGROUND

Enterovirus 71 (EV71) infection results in some severe complications with high mortality and disability in Hand, Foot and Mouth Disease (HFMD) in children. Recent studies have shown that cytokine genetic predispositions have associations with both the development of EV71 infection and severity of HFMD.

OBJECTIVE

This study was designed to investigate whether the IL-10-592 polymorphism is associated with IL-10 levels and disease severity in Chinese children with EV71 infection.

STUDY DESIGN

In patients selected, there were 378 cases with EV71 infection (including 291 mild cases, 70 severe cases and 17 critical cases), as well as 406 health controls. EV71 in serum was tested by RT-PCR, and IL-10-592 genotype was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis techniques.

RESULT

The IL-10-592C allele was observed with higher frequency in patients with critical EV71 infection (70.59%) compared with severe EV71 infection (41.43%, P<0.01), mild EV71 infection (43.81%, P<0.01) and healthy children (44.46%, P<0.01). The blood IL-10 levels of critical cases were significantly higher than severe cases, mild cases, and healthy children. Among all of the four groups, IL-10 levels in patients with genotype AA were significantly lower than those with genotypes AC+CC (t=4.86, P<0.05; t=2.30, P<0.05; t=3.44, P<0.05; t=5.58, P<0.05).

CONCLUSION

IL-10-592C allele is associated with IL-10 expressions and the severity of EV71 infection in Chinese patients.

Advances in the pathogenesis of primary and secondary haemophagocytic lymphohistiocytosis: differences and similarities

Haemophagocytic lymphohistiocytosis (HLH) comprises a heterogeneous spectrum of hyperinflammatory conditions that are inherited (primary HLH) or acquired in a context of infections, malignancies or autoimmune/autoinflammatory disorders (secondary HLH). Genetic defects in the cytotoxic machinery of natural killer and CD8(+) T cells underlie primary HLH, with residual cytotoxicity determining disease severity. Improved sequencing techniques have expanded the range of causal mutations and have redefined many cases of secondary HLH as primary HLH and vice versa, blurring the distinction between both subtypes. These insights allow HLH to be conceptualized as a threshold disease, in which interplay between various genetic and environmental factors causes progressive inflammation into a critical point, beyond which uncontrolled activation of immune cells and excessive cytokine production give rise to the cardinal symptoms of HLH. Various pathogenic pathways may thus converge to a common end stage of fulminant HLH.