Relationship between cytokines gene polymorphism and susceptibility to hepatitis B virus intrauterine infection.

Background: The influences of genomic background are confirmed in more diseases. Immunologic tolerance after intrauterine infection of hepatitis B virus is considered to occur in T cells. Cytokines work effectively in eliminating virus by immune system after hepatitis B virus infection. To explore the relationship between cytokines (tumor necrosis factor-alpha, interferon-gamma, interleukin-4 and interleukin-10), which expressed abnormal quantity in the peripheral blood to intrauterine hepatitis B virus infectious children, gene single nucleotide polymorphism (SNP) and susceptibility to hepatitis B virus intrauterine infection.

Methods: This is a cross sectional study of molecular clinical epidemiology. The subjects in this study were selected from outpatients of hepatitis B vaccine follow-up special clinics of our hospital in the period. According to intrant criteria, the high risk children of hepatitis B virus (HBV) intrauterine infection were divided into immune failure group (group I); and immune effective group (group II) and non high risk children belonged to the control group. Four gene SNP sites of TNF-alpha -238, IFN-gamma +874, IL-4 -590 and IL-10 -1082 were determined by real-time quantitative fluorescent polymerase chain reaction (PCR).

Results: The significant differences of TNF-alpha -238 A allele frequency were found between group I and group II (chi(2) = 6.797, P < 0.05) and between group I and the control group (chi(2) = 9.513, P < 0.05). No evident differences of TNF-alpha -238 A were found between group II and control group (chi(2) = 0.047, P > 0.05); the significant differences of IFN-gamma +874 A allele frequency were found between group I and group II (chi(2) = 7.238, P < 0.05), and between group I and the control group (chi(2) = 5.199, P < 0.05). No evident differences were found between group II and the control group (chi(2) = 0.602, P > 0.05); the significant differences of IL-4 -590 C/T allele frequency were not found between group I and group II (chi(2) = 0.632, P > 0.05), also group I and the control group (chi(2) = 0.584, P > 0.05), and the group II and the control group (chi(2) = 0.004, P > 0.05) respectively; The significant differences of IL-10 -1082 G allele frequency were found between group II and group I (chi(2) = 10.359, P < 0.001), and between group II and the controls (chi(2) = 35.418, P < 0.001), but the significant differences were not found between group I and the control group (chi(2) = 1.759, P > 0.05).

Conclusions: This study suggested the possibility that the TNF-alpha -238 A allele and IFN-gamma +874 A allele were associated with HBV intrauterine infection. There was no evident relationship between IL-4 -590 C/T allele SNP and susceptibility to HBV intrauterine infection, but the IL-10 -1082 G allele was associated with preventive efficacy to HBV intrauterine infection.