Association of the Polymorphism of rs1799822 on Carnitine Palmitoyltransferase II Gene with Severe Enterovirus 71 Encephalitis in Chinese Children.

Mutations of the CPT2 gene cause CPT2 deficiency and affect the ß-oxidation of fatty acids. This study examined the consequence of a polymorphism of rs1799822 in the CPT2 gene with respect to EV71 encephalitis in Chinese children. The study included 406 cases of both mild and severe EV71 infection diagnosed by RT-PCR, together with controls (n = 348). We used an improved multiplex ligation detection reaction technique to detect the polymorphism of rs1799822 in the CPT2 gene. The frequency of the (AG+GG) genotype and G allele in the EV71 infection group and in the severe EV71 encephalitis group was significantly lower than in the control group (p = 0.012 vs. p = 0.005, and p = 0.022 vs. p = 0.006, respectively). The frequency of the (AG+GG) genotype and G allele in the severe EV71 encephalitis group was markedly lower than in the mild EV71 encephalitis group (p = 0.045, p = 0.033). The ATP levels in the blood of the (AG+GG) genotype were distinctly higher than in the AA genotype in mild and severe EV71 encephalitis patients (P = 0.037, P = 0.040). A polymorphism of rs1799822 in the CPT2 gene is associated with the severity of EV71 encephalitis and may be one of the protection factors of severe EV71 encephalitis.

Oligoadenylate synthetase 3 S381R gene polymorphism is associated with severity of EV71 infection in Chinese children.

BACKGROUND: Oligoadenylate synthetase 3 (OAS3) is interferon-induced antiviral enzyme, playing a significant role in the innate immune response. Genetic polymorphism in OAS3 gene has been reported to be a susceptibility factor in many infected diseases, but evidence of its effect on enterovirus 71 (EV71) infection is still lacking. OBJECTIVES: An attempt study was made to investigate whether genetic polymorphism of OAS3 S381R is associated with the severity of EV71 infection in Chinese children. STUDY DESIGN: Retrospectively sumed up the clinical onsets and experimental results for 249 cases with EV71 infection (including 151 mild cases and 98 severe cases) and 243 controls. An improved multiplex ligation detection reaction (iMLDR) technique was carried out to analyze polymorphism in OAS3 S381R G/C gene for genetic association analyses. The plasma levels of IFN-γ were determined by enzyme-linked immunosorbent assays. RESULTS: The distribution of OAS3 S381R CC genotype (73.47%) and C allele (85.20%) in severe cases was markedly higher than in mild cases (45.70%, P < .01; 67.88%, P < .01). The blood IFN-γ levels of severe cases were significantly lower in CC genotype (131.66 ±â€¯10.84 pg/mL) compared to GG (183.37 ±â€¯24.50 pg/mL, p < .01) and GC genotype (168.48 ±â€¯26.57 pg/mL, p < .01). CONCLUSIONS: Carrying the C allele of the OAS3 S381R gene could be a susceptibility factor in the development of severe EV71 infection in Chinese children.

Association of the OAS3 rs1859330 G/A genetic polymorphism with severity of enterovirus-71 infection in Chinese Han children.

The 2'5'-oligoadenylate synthetase (OAS) is an interferon (IFN)-induced protein that plays an important role in the antiviral action of IFN, with OAS3 being one of the four OAS classes (OAS1, OAS2, OAS3, OASL). The effect of OAS on several infectious viral diseases has been reported; however, a study of the effect of OAS3 on enterovirus 71 (EV71) is lacking. The purpose of this study was to evaluate the association of the OAS3 rs1859330 G/A genetic polymorphism with susceptibility and severity of EV71 infection. We investigated 370 Chinese Han children with hand-foot-mouth disease (HFMD) (214 of which were mild cases while 156 were severe). An improved multiplex ligation detection reaction (iMLDR) technique was carried out to examine the genotype. The AA genotype distribution (p = 0.002) and A allele frequency (OR = 1.83, 95% CI 1.32-2.52, p < 0.001) of OAS3 rs1859330 in severe cases were significantly higher than in mild cases. When comparing the different genotypes in EV71-infected patients, there were statistical differences in relation to rash (p = 0.03), oral ulcers (p = 0.005), pathologic reflex (p = 0.003), WBC counts (p = 0.032), CRP (p = 0.024), BG concentrations (p = 0.029), ALT (p = 0.02), and EEG (p = 0.019). However, there were no differences in relation to age, gender, AST, CK-MB, CT/ MRI, as well as some symptoms and signs (e.g. duration of fever (days), headache, convulsions, consciousness disturbance, paralysis, sign of meningeal irritation). In the cerebrospinal fluid (CSF) of severe cases, there were no differences in the levels of white cells, protein, glucose, chloride, lymphocytes and monocytes between the different genotypes. The plasma levels of IFN-γ in EV71-infected patients were significantly higher than in the control group (p < 0.01). IFN-γ concentrations in severe cases were lower in A allele carriers (AA+GA) (118.5 ± 12.6pg/mL) than in GG homozygotes (152.6 ± 56.3pg/mL p < 0.05). These findings suggest that the OAS3 rs1859330 G/A genetic polymorphism is associated with the severity of EV-71 infection, and that the A allele is a risk factor for the development of severe EV71 infection.

Association of Toll-like receptor 3 gene polymorphism with the severity of enterovirus 71 infection in Chinese children.

Enterovirus 71 (EV71) infection has become one of the major threats to children globally in recent years. Toll-like receptor 3 (TLR3) plays an essential role in host defense against EV71 infection. This study was designed to assess the possible association between the TLR3c.1377C/T polymorphism and disease severity in Chinese children with EV71 infection. The TLR3c.1377C/T gene polymorphism was identified in EV71-infected patients (n = 177), including mild cases (n = 99) and severe cases (n = 78) as well as healthy controls (n = 225), using improved multiplex ligation detection reaction (iMLDR) technology. Serum levels of IFN-γ and IL-4 were measured using enzyme-linked immunosorbent assays. The presence of the TT genotype (p = 0.030) and the T allele (OR, 1.8; 95% CI, 1.2-2.8; p = 0.010) was significantly more frequent in severe cases. The plasma levels of IFN-γ and the IFN-γ/IL-4 ratio were significantly lower with the TT (102.0 ± 24.2 pg/mL, p < 0.01 and 14.2 ± 2.8, p < 0.001) and CT genotypes (114.1 ± 26.2 pg/mL, p < 0.05 and 18.0 ± 3.1, p < 0.001) than with the CC genotype (135.5 ± 36.8 pg/mL and 24.9 ± 4.7), but the plasma levels of IL-4 with the TT (7.3 ± 1.7 pg/mL, p < 0.01) and CT genotypes (6.4 ± 1.3 pg/mL, p < 0.05) were significantly higher than with the CC genotype (5.5 ±1.3 pg/mL). These findings suggest that the TLR3c.1377T allele is associated with susceptibility to severe EV71 infection in Chinese children.

[Association of TLR3-1377C/T gene polymorphisms and expression with susceptibility to enterovirus 71 encephalitis in children].

OBJECTIVE: To investigate the association of gene polymorphisms of Toll-like receptor 3 (TLR3)-1377C/T and expression of TLR3 with the susceptibility to enterovirus 71 (EV71) encephalitis in children. METHODS: A total of 187 children with EV71 infection (59 children in the encephalitis group and 128 in the non-encephalitis group) and 232 children who underwent physical examination were enrolled in the case-control study. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the TLR3-1377C/T gene polymorphisms. ELISA was used to measure the serum level of TLR3. RESULTS: There were no significant differences in the genotype and allele frequencies of TLR3-1377C/T between the non-encephalitis group and the encephalitis group. Compared with the control group, the encephalitis group and the non-encephalitis group had significant increases in the serum level of TLR3 (P<0.05), and the non-encephalitis group had the highest level (P<0.05). The encephalitis group had a significantly higher EV71 viral load than the non-encephalitis group (P<0.01). The children aged <1 year or ≥1 year in the encephalitis group and the non-encephalitis group had significant increases in the serum level of TLR3 compared with their counterparts in the control group (P<0.05), and the children aged <1 year or ≥1 year in the non-encephalitis group had a significantly higher serum level of TLR3 than those in the encephalitis group (P<0.05). In the encephalitis group, the children aged ≥1 year had a significantly higher TLR3 concentration than those aged <1 year (P<0.05), and there were no significant differences in the TLR3 concentration between the children aged ≥1 year and <1 year in the non-encephalitis group and the control group. In the encephalitis group, the proportion of children aged <1 year was significantly higher than those aged ≥1 year (P<0.05). CONCLUSIONS: The TLR3-1377C/T gene polymorphisms are not significantly associated with the development of EV71 encephalitis. Low expression of TLR3 might weaken the inhibitory effect on virus replication and promote the development of EV71 encephalitis. The deficiency in the expression of TLR3 in serum after EV71 infection might be an important factor for the development of encephalitis in infants.