Antibodies to HBV surface antigen in relation to interferon-λ3 in hemodialysis patients

Interferon-λ3 Gene Polymorphic Variants, rs4803217 and rs12980275, Responsiveness to HBV Vaccine and Outcome of HBV and HCV Exposure in Hemodialyzed Patients

Background: In non-uremic populations, rs4803217 in the IFNL3 messenger RNA 3’ untranslated region or rs12980275 downstream of IFNL3 is connected with the spontaneous or therapeutic clearance of HCV and HBV, and rs12980275 is correlated with plasma IFN-λ3 levels. Moreover, rs12980275 is associated with the sustained virological response following antiviral therapy of chronic hepatitis C in hemodialysis patients. Objectives: We investigated IFNL3 polymorphisms, rs4803217 and rs12980275, for association with responsiveness to HBV vaccine and natural consequences of HBV and HCV exposure among hemodialyzed individuals. Methods: The capacity to produce protective anti-HBs titers was recognized if they were ≥ 10 IU/L after vaccination or natural exposure. The IFNL3 rs4803217 (G>T) and rs12980275 (A>G) genetic variants were analyzed using a high-resolution melting curve method in 1,337 hemodialysis subjects. Plasma IFN-λ3 was determined in 188 individuals using ELISA. The Kaplan-Meier method was applied for the analysis of survival probability. Results: The tested polymorphisms did not show associations with the capacity to generate protective anti-HBs titers after HBV vaccination or exposition and self-limitation of HBV exposure. Natural HCV clearance was connected with the IFNL3 rs4803217 GG genotype (OR: 3.036, 95% CI: 1.544 - 5.969, P = 0.001) and haplotypes comprising at least two more frequent alleles but without any variant allele of IFNL3/IFNL4 genetic variants (P < 0.05). Plasma IFN-λ3 levels were not directly influenced by IFNL3 rs4803217 and rs12980275, but differed concerning HBV/HCV serum markers (P = 0.00005) and firmly correlated with anti-HBs titers (r = 0.537, P = 4.15E-16). Both tested polymorphisms were not significantly associated with the survival of hemodialysis patients. Conclusions: Genotyping IFNL3 rs4803217 may be advantageous in the prognosis of natural HCV clearance but does not predict the self-limitation of HBV exposure, responsiveness to HBV vaccine, or hemodialysis patients’ mortality.

Circulating interferon-λ3 and post-vaccination antibodies against the surface antigen of hepatitis B virus in hemodialysis patients exposed to hepatitis E virus

Responsiveness to the hepatitis B virus (HBV) vaccination in hemodialysis (HD) patients who had been exposed to the hepatitis E virus (HEV) and persistently generate antibodies against HEV remains unknown. Interferon (IFN)-λ3 positively correlates with the surface HBV antibodies (anti-HBs) in both healthy and HD subjects. We aimed to show whether HD patients differ in circulating IFN-λ3 and vaccine-induced anti-HBs titers concerning natural HEV immunization. HBV/HCV negative HD patients (31 HEV IgG positive, 45 HEV negative), HBV vaccinated and receiving booster doses as needed, had been tested for anti-HBs titers (CMIA) and IFN-λ3 concentrations (ELISA) in the blood collected before a dialysis session. There were no differences in circulating IFN-λ3 and anti-HBs titers between both groups. In responders to the HBV vaccine, there was a positive correlation between plasma IFN-λ3 levels and anti-HBs titers (r = 0.505, adjusted P = 0.01 in HEV exposed subjects; r = 0.523, adjusted P = 0.001 in controls). HEV past infection does not attenuate post-vaccination anti-HBs generation and does not influence a correlation between circulating IFN-λ3 levels and anti-HBs titers.

Genetic Polymorphisms within Interferon-λ Region and Interferon-λ3 in the Human Pathophysiology: Their Contribution to Outcome, Treatment, and Prevention of Infections with Hepatotropic Viruses

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Genetic polymorphisms within the interferon λ (IFN-λ) chromosomal region, mainly rs12979860 of IFN-λ4 gene (IFNL4), are known as associated with spontaneous hepatitis C virus (HCV) resolution and sustained viral response to therapy with pegylated interferon- α and ribavirin. Strong linkage disequilibrium of IFNL4 rs12979860 with IFNL4 rs368234815, which is casually associated with HCV spontaneous and therapeutical eradication, at least partially explains favorable HCV outcomes attributed to major homozygosity in rs12979860. Effects of IFN-based antiviral treatment are associated with pretreatment expression of the IFN-λ1 receptor, expression of hepatic IFN-stimulated genes, production of IFN- λ4, and preactivation of the JAK-STAT signaling. Nowadays direct-acting antivirals (DAAs) became a potent tool in the treatment of hepatitis C, but IFN-λs are still under investigation as potential antivirals and might be an option in HCV infection (DAA resistance, recurrent viremia, adverse effects).

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Patients with altered immunocompetence are especially prone to infections. In uremic subjects, polymorphisms within the IFN-λ chromosomal region associate with spontaneous HCV clearance, similarly like in the non-uremic population. Circulating IFN-λ3 shows a positive correlation with plasma titers of antibodies to surface antigen of hepatitis B virus (anti-HBs), which are crucial for protection against hepatitis B virus. More efficient anti-HBs production in the presence of higher IFN-λ3 levels might occur due to IFN-λ3-induced regulation of indoleamine 2,3-dioxygenase (IDO) expression. IFN-stimulated response element is a part of IDO gene promoter. It is worth further investigation whether IDO gene, circulating IDO, genetic polymorphisms within the IFN-λ region, and circulating IFN-λ3 act in concordance in immunological response to hepatotropic viruses.

Circulating Interferon-λ3, Responsiveness to HBV Vaccination, and HBV/HCV Infections in Haemodialysis Patients

The IFN-λ3 gene (IFNL3) plays a role in HCV clearance. We investigated circulating IFN-λ3 and IFNL3 SNPs in haemodialysis patients who differed in their response to HBV vaccination and their HBV/HCV infection status. In 201 patients, plasma IFN-λ3 was determined using ELISA. IFNL3 SNPs (rs12979860, rs8099917) were genotyped using HRM analysis. Differences in IFN-λ3 levels were shown between responders and nonresponders to HBV vaccination and between HBsAg-positive patients and those who developed anti-HBs after infection and became HBsAg negative. HBV vaccine responders without HCV resolution revealed lower IFN-λ3 than noninfected responders. HBsAg/HCV RNA-positive subjects showed lower IFN-λ3 than patients positive only for HCV RNA or subjects who resolved both infections. Circulating IFN-λ3 correlated positively with anti-HBs and negatively with positive HCV RNA testing in the adjusted regression analyses. HBV vaccine nonresponders, HBsAg-positive patients, and subjects with replicating HCV composed a group with unfavourable outcomes. Responders to HBV vaccination, subjects who became HBsAg negative, and those who cleared HCV were analysed as having favourable outcomes. The latter showed higher IFN-λ3 but did not differ in distribution of IFNL3 SNPs compared with subjects with unfavourable outcomes. Higher IFN-λ3 concentrations are associated with response to HBV vaccination, self-limited HBV infection, and HCV resolution.

Polymorphisms of T helper cell cytokine-associated genes and survival of hemodialysis patients - a prospective study

BACKGROUND

Circulating pro-inflammatory cytokines were associated with increased relative mortality risk, while immune parameters reflecting improved T-cell function were predictors of survival in hemodialysis (HD) patients. We evaluated in the prospective study whether variants in T helper cell cytokine-associated genes are determinants of mortality in HD patients.

METHODS

The study was carried out in 532 prevalent HD subjects who were followed-up for 7 years. HRM analysis was used for IFNL3, IL12A, IL13, and IL4R genotyping. CCL2, IL12B, and IL18 were genotyped using PCR-RFLP analysis. Survival analyses were conducted using the Kaplan-Meier method and the Cox proportional hazard model.

RESULTS

In univariate analyses, IFNL3 rs8099917 was associated with all-cause mortality in recessive model of inheritance (log-rank test P = 0.044), IL12A rs568408 - in dominant model (log-rank test P = 0.029). Minor homozygotes (the genotype GG) in IFNL3 rs8099917 showed shorter survival during the study (3.6, 1.0-7.0 years vs 4.7, 0.1-7.0 years, P = 0.009) than the major allele (T) bearers. The rs8099917 GG patients demonstrated higher risk of death than the remaining patients (GT + TT) (OR 1.94, 95%CI 1.11-3.40, P = 0.020). Major homozygosity (the genotype GG) in IL12A rs568408 was associated with higher mortality than that shown in bearers of the minor allele (AA + AG) (HR 1.31, 95%CI 1.02-1.69, P = 0.035). In multivariate analyses, however, the mentioned polymorphisms were not independent predictors of survival.

CONCLUSIONS

Polymorphisms of IFNL3 rs8099917 and IL12A rs568408 contribute to survival of HD patients, but not as independent factors.