HLA-DRB1*010101 allele is closely associated with poor virological response to lamivudine therapy in patients with chronic hepatitis B

Clinical Relevance of HLA Gene Variants in HBV Infection

Host gene variants may influence the natural history of hepatitis B virus (HBV) infection. The human leukocyte antigen (HLA) system, the major histocompatibility complex (MHC) in humans, is one of the most important host factors that are correlated with the clinical course of HBV infection. Genome-wide association studies (GWASs) have shown that single nucleotide polymorphisms (SNPs) near certain HLA gene loci are strongly associated with not only persistent HBV infection but also spontaneous HBV clearance and seroconversion, disease progression, and the development of liver cirrhosis and HBV-related hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB). These variations also influence the efficacy of interferon (IFN) and nucleot(s)ide analogue (NA) treatment and response to HBV vaccines. Meanwhile, discrepant conclusions were reached with different patient cohorts. It is therefore essential to identify the associations of specific HLA allele variants with disease progression and viral clearance in chronic HBV infection among different ethnic populations. A better understanding of HLA polymorphism relevance in HBV infection outcome would enable us to elucidate the roles of HLA SNPs in the pathogenesis and clearance of HBV in different areas and ethnic groups, to improve strategies for the prevention and treatment of chronic HBV infection.

Association between gene polymorphisms of IL-28 and response to lamivudine in Chinese rural patients with chronic hepatitis B

OBJECTIVE

To assess the association between gene polymorphisms (single nucleotide polymorphisms [SNPs]) of rs8099917 and rs12980602 in the IL-28 gene and the response to lamivudine treatment in naïve of Chinese rural patients.

MATERIAL AND METHODS

Three hundred and fifty-four naïve chronic hepatitis B (CHB) patients treated with lamivudine were enrolled in this study. Rs8099917 and rs12980602 SNPs were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Baseline characteristics and genotypes were compared between 181 patients with treatment response and 173 without response.

RESULTS

The IL-28 genotypes were independently associated with responses at 1 year post-treatment with lamivudine in CHB patients (OR for rs8099917 GT/GG vs. TT, 4.097 [95% CI, 1.342-12.512; p = 0.015]; OR for rs12980602CT/CC vs. TT, 2.27 [95% CI, 1.202-4.284; p =0.014]). When adjusting for age, gender, smoking, drinking, and levels of hepatitis B virus (HBV) DNA, alanine aminotransferase, and HBV genotype, the rs8099917 genotype GT (OR, 4.025 [95% CI, 1.316-12.354; p = 0.013] and fibrosis stage (OR, 0.716 [95% CI, 0.432-0.986; p = 0.036] appeared to be associated with a higher probability of response to lamivudine treatment.

CONCLUSION

The genotype G/T for rs8099917 of IL-28 gene and early fibrosis stage may be predictive of treatment success.

Polymorphism of estrogen receptor alpha (ESR1) is associated with virological response to entecavir (ETV) in nucleoside-naïve adult patients with chronic hepatitis B

INTRODUCTION

Polymorphisms in estrogen receptor alpha (ESR1) are reported to be associated with the susceptibility to persistent HBV infection, HBV liver cirrhosis and HBV-related hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

To test the hypothesis that polymorphisms in estrogen receptor alpha (ESR1) might influence the virological response to entecavir (ETV) therapy, we examined two polymorphisms (PvuII and XbaI) in 76 nucleoside-naïve chronic hepatitis B (CHB) patients. All of the patients (52 HBeAg-positive and 24 HBeAg-negative) were treated with ETV 0.5 mg daily and followed up for a median time of 96 weeks (range 48-96). Polymorphisms were determined using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method.

RESULTS

Under an additive model, the univariate analysis showed that patients carrying the PvuII T/C genotype might have higher virological responders than those carrying the T/T and C/C genotypes at week 48 (87.7 vs. 57.1 vs. 58.3 %; P = 0.012) and week 96 (96.7 vs. 64.3 vs. 24 87.5 %; P = 0.018), although this difference disappeared with the multiple analysis at week 48 [95 % confidence interval (CI) 0.687-3.841; P = 0.269] and week 96 (95 % CI 0.861-18.016; P = 0.077). Conversely, the univariate analysis suggests statistical significance between the recessive model of PvuII (TT vs. TC/CC) and virological response at week 48 (57.1 vs. 81.1 %; P = 0.033) and week 96 (64.3 vs. 94.7 %; P = 0.017). Multiple regression analysis affirmed the significant and independent association between the recessive model of PvuII and virological response. In other words, patients carrying at least one PvuII C allele (TC/CC) had a better likelihood of achieving virological response compared with those carrying the T/T genotype at week 48 (95 % CI 1.026-14.785, P = 0.046) and week 96 (95 % CI 1.456-57.509; P = 0.018). XbaI polymorphisms were not significantly associated with virological response.

CONCLUSION

Our results suggest that the PvuII polymorphism may play an important role in determining ETV efficacy after 48 and 96 weeks of treatment, at least in this study population.