A promoter polymorphism (rs3806798) of interleukin-15 gene is associated with chronic hepatitis B virus infection in the Chinese Han population

IL15 polymorphism is associated with advanced fibrosis, inflammation-related biomarkers and virological response in human immunodeficiency virus/hepatitis C virus coinfection

BACKGROUND & AIMS

IL15 is an essential cytokine in both innate and adaptive immune response against hepatitis C virus (HCV) infection. The aim was to analyze whether IL15 rs10833 is associated with liver disease severity and response to pegylated-interferon-alpha plus ribavirin (pegIFN-alpha/RBV) therapy in human immunodeficiency virus (HIV)-/HCV-co-infected patients.

METHODS

A retrospective study was performed in 315 patients who started pegIFN-alpha/RBV therapy. Liver fibrosis stage was characterized in 286 patients. IL15 rs10833 and IL28B rs12980275 were genotyped by GoldenGate. The primary outcomes were: (a) advanced liver fibrosis evaluated by liver biopsy (F3-F4) or transient elastography (liver stiffness values ≥9.5 Kpa); (b) sustained virological response (SVR). The secondary outcome variable was the levels of serum biomarkers of inflammation.

RESULTS

Patients with rs10833 AA genotype had increased odds of having advanced fibrosis (adjusted odds ratio (aOR) = 2.30; P = 0.019), particularly in males (aOR = 2.24; P = 0.040), patients with HCV serum viral load (HCV-RNA) <500 000 IU/ml (aOR = 5.14; P = 0.018) and patients with IL28B rs12980275 AG/GG genotypes (aOR = 2.51; P = 0.046). Moreover, rs10833 AA genotype was significantly associated with higher levels of hepatocyte growth factor (adjusted arithmetic mean ratio (aAMR) = 1.50; P = 0.016), sICAM-1 (aAMR = 1.57; P = 0.025) and sVCAM-1 (aAMR = 1.56; P = 0.007). Finally, patients with rs10833 AA genotype had increased odds of achieving SVR (aOR = 3.12; P = 0.006), particularly in males (aOR = 3.69; P = 0.005), GT1/4 patients (aOR = 3.59; P = 0.006), patients with advanced fibrosis (aOR = 4.64; P = 0.021), HCV-RNA ≥500 000 IU/ml (aOR = 3.92; P = 0.007) and patients with IL28B rs12980275 AG/GG genotype (aOR = 2.98; P = 0.041).

CONCLUSIONS

The presence of IL15 rs10833 AA genotype in HIV-/HCV-co-infected patients was associated with advanced liver fibrosis, inflammation-related biomarkers and increased rates of SVR to pegIFN-alpha/RBV therapy.

Deltex1 Polymorphisms Are Associated with Hepatitis B Vaccination Non-Response in Southwest China

Background

Hepatitis B vaccination is the most important tool available for preventing hepatitis B virus (HBV) infection and reducing the prevalence of infection. However, epidemiological studies have demonstrated that morethan 5% of patients exhibit a non- or hypo-response to the HBV vaccine. Genetic variations associated with T cell immunity contribute to the immune response to HBV vaccination. The deltex 1 (DTX1) gene is involved in T cell anergy, which may also be associated with the immune response to the HBV vaccination.

Methods

We detected 10 single nucleotide polymorphisms (SNPs) in or around the DTX1 gene in 601 infants out of a population from Southwest China, including 299 high responders(HRs; HBsAb > 100 mIU/mL) and 302 non-responders (NRs; HBsAb < 10 mIU/mL). An additional validation study was performed, comprising 230 adult patients(135 HRs and 95 NRs) from Southwest China.

Results

This study found that the minor allele ‘G’ of rs2384077 (adjusted p = 2.63E^-04,) and the minor allele ‘C’ of rs10744794 (adjusted p = 3.69E^-04) in the first intron of the DTX1 gene were remarkably associated with the immune response to HBV vaccination in both infant and adult populations. Moreover, a subsequent analysis indicated that haplotypes (A-T, G-C) of the two SNPs were significantly associated with the immune response to HBV vaccination.

Conclusions

Two SNPs (rs2384077 and rs10744794) in an intron of DTX1 and the linkage disequilibrium (LD) block are significantly associated with the immune response to HBV vaccination. The functional element annotation of the LD block between the two SNPs contains four transcriptional regulatory elements. The results suggest that these two SNPs may be involved in the immune response to HBV vaccination.