Current molecular methods for the detection of hepatitis B virus quasispecies.

Chronic HBV infection affects more than 240 million people worldwide and is associated with a broad range of clinical manifestations including liver cirrhosis, liver failure and hepatocellular carcinoma. Because of the lack of an efficient cure for chronic hepatitis B, the main goal of antiviral therapy is the prevention of liver disease progression coupled with prolonged survival of patients. Because HBV viral load has been shown to be a crucial determinant of the progression of liver damage, these goals can be achieved as long as HBV replication can be suppressed. Unfortunately, long-term therapy with the low-to-moderate genetic barrier drugs, which are still recommended in a majority of developing countries, are strongly associated with HBV resistance development and treatment failure. In such cases, the precise and accurate determination of drug-resistant variants in an individual patient before treatment is important for a proper choice of first-line potent therapy. Nowadays, a number of techniques are available to study HBV quasispecies evolution. This review describes the advantages and limitations of various assays detecting drug-resistant HBV variants. Copyright © 2016 John Wiley & Sons, Ltd.

Photoinactivation of Staphylococcus aureus using protoporphyrin IX: the role of haem-regulated transporter HrtA.

Light- and photosensitiser-based antimicrobial photodynamic therapy is a very promising approach to the control of microbial infections. How the phenotypic features of a microorganism affect its response to photosensitiser-based photokilling represents an area of substantial research interest. To understand the mechanisms governing the phenomenon of a strain-dependent response to photodynamic inactivation (PDI), we analysed the possible role of the membrane-located haem transporter HrtA in Staphylococcus aureus. We used a S. aureus strains with an inactivated component of the haem-regulated transporter, HrtA, along with its wild-type counterpart to determine differences in PDI outcome and photosensitiser uptake between the studied isogenic strains. We observed that a lack of HrtA protein potentiates the phototoxic effect towards S. aureus but only when extracellular protoporphyrin IX is used. The observed effect may depend on the function of the HrtA transporter but is likely to result from changed membrane properties following the absence of the protein in the membrane. This indicates that disturbing the membrane properties is an attractive method for improving the efficacy of the photodynamic inactivation of microorganisms.

High-throughput matrix-assisted laser desorption ionization-time of flight mass spectrometry as an alternative approach to monitoring drug resistance of hepatitis B virus.

Long-term antiviral therapy of chronic hepatitis B virus (HBV) infection can lead to the selection of drug-resistant HBV variants and treatment failure. Moreover, these HBV strains are possibly present in treatment-naive patients. Currently available assays for the detection of HBV drug resistance can identify mutants that constitute ≥5% of the viral population. Furthermore, drug-resistant HBV variants can be detected when a viral load is >10(4) copies/ml (1,718 IU/ml). The aim of this study was to compare matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and multitemperature single-strand conformation polymorphism (MSSCP) with commercially available assays for the detection of drug-resistant HBV strains. HBV DNA was extracted from 87 serum samples acquired from 45 chronic hepatitis B (CHB) patients. The 37 selected HBV variants were analyzed in 4 separate primer extension reactions on the MALDI-TOF MS. Moreover, MSSCP for identifying drug-resistant HBV YMDD variants was developed and turned out to be more sensitive than INNOLiPA HBV DR and direct sequencing. MALDI-TOF MS had the capability to detect mutant strains within a mixed viral population occurring with an allelic frequency of approximately 1% (with a specific value of ≥10(2) copies/ml, also expressed as ≥17.18 IU/ml). In our study, MSSCP detected 98% of the HBV YMDD variants among strains detected by the MALDI-TOF MS assay. The routine tests revealed results of 40% and 11%, respectively, for INNOLiPA and direct sequencing. The commonly available HBV tests are less sensitive than MALDI-TOF MS in the detection of HBV-resistant variants, including quasispecies.

An initial assessment of correlations between host- and virus-related factors affecting analogues antiviral therapy in HBV chronically infected patients.

BACKGROUND: Success in treating hepatitis B virus (HBV) infection with nucleoside analogues drugs is limited by the emergence of drug-resistant viral strains upon prolonged therapy. In addition to mutation patterns in the viral polymerase gene, host factors are assumed to contribute to failure of treatment in chronic HBV infections. The aim of this study was to analyze the correlation between efficacy of antiviral therapy and the prevalence of HBV pretreatment drug-resistant variants. We also analyzed the role of heterogeneity in the promoter region of the IL-10 on the HBV pol/s gene polymorphisms and efficacy of analogues-driven therapy. MATERIAL AND METHODS: HBV DNA was extracted from 54 serum samples from chronic hepatitis B (CHB) patients. Drug-resistance mutations were analyzed using MALDI-TOF mass spectrometry technology (MALDI-TOF MS) and Multi-temperature single-strand conformation polymorphism (MSSCP). IL-10 gene promoter region polymorphisms at positions -1082, -819, and -592 were determined in allele-specific PCR reactions (AS-PCR). RESULTS: Drug-resistance mutations were detected in 74% of naïve and 93% of experienced patients, but the effect of pre-existence of drug-resistant HBV variants on antiviral therapy was not statistically significant (p=0.86). The role of polymorphisms at positions -1082 (p=0.88), -819 (p=0.26), and -592 (p=0.26) of IL-10 promoter region polymorphisms was excluded from the response-predicting factors. The main host factors predicting successful response to antiviral therapy were female sex (p=0.007) and young age (p=0.013). CONCLUSIONS: The presence of drug-resistant HBV variants in baseline is not a viral predictor of good response to nucleoside/nucleotide analogues therapy. Only low HBV viral load predicted positive response to antiviral therapy. The ideal candidate for antiviral therapy is an immunocompetent, young female with low HBV viral load and elevated ALT activity.

Liver steatosis correlates with iron overload but not with HFE gene mutations in chronic hepatitis C.

BACKGROUND: Liver steatosis and iron overload, which are frequently observed in chronic hepatitis C (CHC), may contribute to the progression of liver injury. This study aimed to evaluate the correlation between liver steatosis and iron overload in Polish patients with CHC compared to non-alcoholic fatty liver disease (NAFLD) and HFE-hereditary hemochromatosis (HH) patients. METHODS: A total of 191 CHC patients were compared with 67 NAFLD and 21 HH patients. Liver function tests, serum markers of iron metabolism, cholesterol and triglycerides were assayed. The inflammatory activity, fibrosis, iron deposits and steatosis stages were assessed in liver specimens. HFE gene polymorphisms were investigated by PCR-RFLP. RESULTS: Liver steatosis was associated with obesity and diabetes mellitus. This disease was confirmed in 76/174 (44%) CHC patients, most of whom were infected with genotype 1. The average grade of steatosis was higher in NAFLD patients. CHC patients had significantly higher iron concentrations and transferrin saturations than NAFLD patients. Compared with CHC patients, HH patients had higher values of serum iron parameters and more intensive hepatocyte iron deposits without differences in the prevalence and intensity of liver steatosis. In the CHC group, lipids accumulation in hepatocytes was significantly associated with the presence of serum markers of iron overload. No correlation between the HFE gene polymorphism and liver steatosis in CHC patients was found. CONCLUSIONS: Liver steatosis was diagnosed in nearly half of CHC patients, most of whom were infected with genotype 1. The intensity of steatosis was lower in CHC patients than that in NAFLD patients because of a less frequent diagnosis of metabolic syndrome. Only in CHC patients were biochemical markers of iron accumulation positively correlated with liver steatosis; these findings were independent of HFE gene mutations.

Polymorphisms within DIO2 and GADD45A genes increase the risk of liver disease progression in chronic hepatitis b carriers.

The study enrolled 284 patients with chronic hepatitis B virus infection. Participants included people with mild fibrotic lesions (32.5%), moderate to severe fibrotic lesions (27.5%), cirrhotic lesions (22%), hepatocellular carcinoma (HCC) in 5%, and people with no fibrotic lesions in 13%. Eleven SNPs within DIO2, PPARG, ATF3, AKT, GADD45A, and TBX21 were genotyped by mass spectrometry. The rs225014 TT (DIO2) and rs10865710 CC (PPARG) genotypes were independently associated with susceptibility to advanced liver fibrosis. However, cirrhosis was more prevalent in individuals with the GADD45A rs532446 TT and ATF3 rs11119982 TT genotypes. In addition, the rs225014 CC variant of DIO2 was more frequently found in patients with a diagnosis of HCC. These findings suggest that the above SNPs may play a role in HBV-induced liver damage in a Caucasian population.

Iron overload and HFE gene mutations in Polish patients with liver cirrhosis.

BACKGROUND: Increased liver iron stores may contribute to the progression of liver injury and fibrosis, and are associated with a higher risk of hepatocellular carcinoma development. Pre-transplant symptoms of iron overload in patients with liver cirrhosis are associated with higher risk of infectious and malignant complications in liver transplant recipients. HFE gene mutations may be involved in the pathogenesis of liver iron overload and influence the progression of chronic liver diseases of different origins. This study was designed to determine the prevalence of iron overload in relation to HFE gene mutations among Polish patients with liver cirrhosis. METHODS: Sixty-one patients with liver cirrhosis included in the study were compared with a control group of 42 consecutive patients subjected to liver biopsy because of chronic liver diseases. Liver function tests and serum iron markers were assessed in both groups. All patients were screened for HFE mutations (C282Y, H63D, S65C). Thirty-six of 61 patients from the study group and all controls had liver biopsy performed with semiquantitative assessment of iron deposits in hepatocytes. RESULTS: The biochemical markers of iron overload and iron deposits in the liver were detected with a higher frequency (70% and 47% respectively) in patients with liver cirrhosis. There were no differences in the prevalence of all HFE mutations in both groups. In patients with a diagnosis of hepatocellular carcinoma, no significant associations with iron disorders and HFE gene mutations were found. CONCLUSIONS: Iron disorders were detected in patients with liver cirrhosis frequently but without significant association with HFE gene mutations. Only the homozygous C282Y mutation seems to occur more frequently in the selected population of patients with liver cirrhosis. As elevated biochemical iron indices accompanied liver iron deposits more frequently in liver cirrhosis compared to controls with chronic liver disease, there is a need for more extensive studies searching for the possible influence of non-HFE iron homeostasis regulators and their modulation on the course of chronic liver disease and liver cirrhosis.

Host response to the presence of Helicobacter spp. DNA in the liver of patients with chronic liver diseases.

Literature data indicate an association between the presence of Helicobacter spp. in the liver and the development of hepatocellular carcinoma (HCC). However, the role of H. pylori infections in chronic liver diseases (CLD) remains controversial. The aim of this study was to detect Helicobacter spp. DNA in patients with CLD, and to investigate the host response to the presence of the bacterium in the liver. Helicobacter spp. DNA was detected in 59% samples. H.pylori was the most prevalent species (94%). We estimated the expression level of IL-1 and IL-8 genes. The presence of Helicobacter spp. did not have a significant effect on the gene expression of IL-8 and IL-1.

[The influence of hepatitis B virus polymorphism on the progression of chronic liver disease]. / Wplyw polimorfizmu wirusa zapalenia watroby typu B na przebieg choroby u osób przewlekle zakazonych.

Hepatitis B virus (HBV) infection is one of the major human health problems worldwide. It is estimated that chronic HBV infection affects more than 350 million people globally. It is one of the leading causes of liver cirrhosis and hepatocellular carcinoma. High genetic variability is a characteristic feature of HBV as the viral polymerase lacks proofreading activity. The nucleotide substitution rate for HBV is 10-fold higher than for other DNA viruses. Genetic variations of HBV influence the clinical outcome of HBV infection. There are eight genotypes of hepatitis B virus (A-H) that have a distinct geographical distribution. There is clinical significance of HBV genotype in terms of disease activity, risk of progression to cirrhosis, the development of hepatocellular carcinoma and response to antiviral treatments. Moreover, polymorphism in HBV viral polymerase influences the development of HBV mutants resistant to nucleotide analogue treatment that is a consequence of treatment failure.

Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus.

The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.

Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection.

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

(Re-)activity in the caregiving situation: Genetic diversity within Oxytocin-Vasopressin Pathway is associated with salivary oxytocin and vasopressin concentrations in response to contact with a crying infant-simulator.

Oxytocin (OT) and vasopressin (AVP) hormones as well as their receptors (OXTR and AVPR1a) have been deemed crucial for caregiving and sensitive responsiveness to infant cues. However, previous research on genetic polymorphisms and OT and AVP levels in the context of caregiving were sparse and have brought contradictory findings. The aim of this reported observational study was to examine the impact of genetic variations within genes related to OT and AVP signaling pathway on hormones levels' changes in response to the caregiving situation. A total of 221 adult intimate couples (110 childless, non-pregnant and 111 expectant couples) participated in three 10 min sessions, during which they were taking care of a crying life-like simulator. 30 min prior to the first session salivary samples to analyze basal OT and AVP, and polymorphisms in OXTR, AVPR1a and CD38 genes were collected. Subsequent OT and AVP levels were measured 15 min after each session. The two most frequently studied OXTR SNPs (rs53576 and rs2254298) had no or a minor impact on higher OT levels, which were linked to rs1042778, rs13316193, rs2228485, rs2268490, rs4686302 genotypes. AVP levels were affected by rs1042778, rs13316193, rs4686302 and rs237887. OT levels varied depending on the OT (rs2770378, rs4813625), CD38 (rs379686), and 5-HTR2A (rs6314) genotype. OT and AVP levels were also associated with rs6314 (5-HTR2A). AVP levels were linked to ESR1 (rs1884051) and SIM1 (rs3734354) variations. Shorter variants of RS3 and RS1 were associated with lower levels of AVP. In conclusion, analyzed polymorphisms were associated with both the level and changes in OT and AVP hormone levels in the standardized situation of caregiving reactions to infant crying.

The role of iron overload and HFE gene mutations in the era of pegylated interferon and ribavirin treatment of chronic hepatitis C.

BACKGROUND: Iron overload observed in chronic hepatitis C (CHC) has been suggested to be one of the negative prognostic factors influencing liver disease progression and failure of treatment with recombinant interferon in monotherapy or in combination with ribavirin. The aim of this study was to assess occurrence of iron overload in relation to polymorphism of the HFE and the influence of both these factors on efficacy of antiviral treatment with pegylated interferon and ribavirin in patients with CHC. MATERIAL/METHODS: Liver function tests, serum indices of iron metabolism, and HFE mutations were assayed in 152 patients with CHC from Poland. Histopathological examination of the liver biopsy specimen was performed in 138 patients. Sixty-one patients were treated with pegylated interferon alfa-2 and ribavirin. The comparative analysis was performed in 2 groups of patients: those with and those without elevated serum indices of iron metabolism. RESULTS: Increased biochemical iron metabolism parameters correlated with older age, higher ALT activity, more advanced liver fibrosis and treatment failure. Iron deposits in liver specimens were not accompanied by exacerbation of necro-inflammatory activity and advanced fibrosis. Elevated biochemical values of iron metabolism parameters and presence of hepatic iron deposits correlated positively with C282Y mutations. The lack of sustained viral response after treatment with pegylated interferon and ribavirin was observed more frequently in carriers of HFE mutations. CONCLUSIONS: Iron overload was frequently detected in patients with CHC, and was associated only with C282Y alleles. Biochemical markers of iron overload and HFE gene mutations were negative prognostic factors of antiviral treatment.

[Helicobacter spp. infections in chronic liver damage]. / Zakazenia bakteriami rodzaju Helicobacter spp. w przewleklym uszkodzeniu watroby.

Liver is a key organ responsible for organism's homeostasis. A proper function of this organ is crucial for detoxification of metabolic products and regulation of metabolic processes of macromolecules (proteins, lipids, carbohydrates). The most important infectious factors, leading to liver damage, are primary hepatotropic viruses, particularly those causing chronic inflammation of the organ (HBV, HCV, HDV), which may subsequently cause cirrhosis and/or primary hepatocellular carcinoma. There has been a growing interest in Helicobacter spp. liver infections as a potential factor promoting injury of the organ towards hepatocellular carcinoma. The association between hepatocellular carcinoma and the presence of Helicobacters in the liver has been well documented in animal models (Helicobacter hepaticus versus liver cancer in mice). Some reports also indicate similar association in humans, where the presence of Helicobacter antigens in patients with liver cancer is detected more often in comparison to healthy or chronically infected population. Although the molecular mechanisms underlying such a phenomenon are not well known, the knowledge on this subject has considerably increased during recent years. The review presents data on the association between the presence of Helicobacter spp. in the liver and injuries of the organ, as well as the role that is played by the bacteria in chronic liver diseases.

Recent Advances in Understanding, Diagnosing, and Treating Hepatitis B Virus Infection.

Chronic hepatitis B virus (HBV) infection affects 292 million people worldwide and is associated with a broad range of clinical manifestations including cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Despite the availability of an effective vaccine HBV still causes nearly 900,000 deaths every year. Current treatment options keep HBV under control, but they do not offer a cure as they cannot completely clear HBV from infected hepatocytes. The recent development of reliable cell culture systems allowed for a better understanding of the host and viral mechanisms affecting HBV replication and persistence. Recent advances into the understanding of HBV biology, new potential diagnostic markers of hepatitis B infection, as well as novel antivirals targeting different steps in the HBV replication cycle are summarized in this review article.

Liver Cirrhosis in Chronic Hepatitis B Patients Is Associated with Genetic Variations in DNA Repair Pathway Genes.

Liver cirrhosis (LC), contributing to more than 1 million of deaths annually, is a major healthcare concern worldwide. Hepatitis B virus (HBV) is a major LC etiological factor, and 15% of patients with chronic HBV infection (CHB) develop LC within 5 years. Recently, novel host genetic determinants were shown to influence HBV lifecycle and CHB course. DNA repair enzymes can affect dynamics of liver damage and are involved in HBV covalently closed circular DNA (cccDNA) formation, an essential step for viral replication. This study aimed to evaluate the possible role of genes representing key DNA-repair pathways in HBV-induced liver damage. MALDI-TOF MS genotyping platform was applied to evaluate variations within XRCC1, XRCC4, ERCC2, ERCC5, RAD52, Mre11, and NBN genes. Apart from older age (p < 0.001), female sex (p = 0.021), portal hypertension (p < 0.001), thrombocytopenia (p < 0.001), high HBV DNA (p = 0.001), and high aspartate aminotransferase (AST) (p < 0.001), we found that G allele at rs238406 (ERCC2, p = 0.025), T allele at rs25487 (XRCC1, p = 0.012), rs13181 GG genotype (ERCC2, p = 0.034), and C allele at rs2735383 (NBN, p = 0.042) were also LC risk factors. The multivariate logistic regression model showed that rs25487 CC (p = 0.005) and rs238406 TT (p = 0.027) were independently associated with lower risk of LC. This study provides evidence for the impact of functional and potentially functional variations in key DNA-repair genes XRCC1 and ERCC2 in HBV-induced liver damage in a Caucasian population.

Genetic variation in IL-10 influences the progression of hepatitis B infection.

OBJECTIVES: The outcomes of hepatitis B virus (HBV) infection vary substantially among affected individuals, providing evidence of the role of host genetic background in the susceptibility to HBV persistence and the dynamics of liver injury progression to cirrhosis and hepatocellular carcinoma (HCC). METHODS: Six single-nucleotide polymorphisms within the interleukin 10 gene (IL10) were genotyped by MALDI-TOF mass spectrometry in 857 patients with chronic HBV infection (CHB), 48 patients with resolved HBV infection, and 100 healthy volunteers. Associations of the selected polymorphisms with susceptibility to chronic HBV infection, liver injury progression, and outcomes were investigated. RESULTS: IL10 -819T (rs1800871), -592A (rs1800872), and +504T (rs3024490) alleles were associated with treatment-induced hepatitis B surface antigen (HBsAg) seroclearance. Additionally, IL10 ATAC haplotype increased the chance of HBsAg loss and was significantly more frequent in patients with less liver injury. Moreover rs1800871TT, rs1518110TT, rs1800872AA, and rs3024490TT genotypes were identified as predictors of a lower FIB-4 score (<0.5). CONCLUSIONS: This study indicates that polymorphisms within the promoter region and intronic sequences of IL10 are associated with chronicity of hepatitis B and with HBV-induced liver damage.

UGT1A1 gene polymorphism as a potential factor inducing iron overload in the pathogenesis of type 1 hereditary hemochromatosis.

Aim Hereditary hemochromatosis is a common genetic disorder characterized by iron overload and subsequent organ damage. It is caused in most cases by HFE gene mutations which penetrance can be affected by many factors. The aim of this study was to establish the role of UGT1A1 gene polymorphism and serum bilirubin concentration in the pathogenesis of hereditary hemochromatosis. Methods Biochemical, histopathological and genetic data indicating iron excess and serum total bilirubin concentration were determined in 32 patients with the type 1 hereditary hemochromatosis. Fluorescent molecular probes assays were used for genotyping of UGT1A1*28 and UGT1A1*60 mutations in these individuals. Results High incidence and a significant correlation of UGT1A1 gene mutations with increased serum bilirubin level and lower grades of liver tissue inflammatory activity were observed in study participants. UGT1A1*28 and UGT1A1*60 mutations were strongly linked together. Two of the subjects presented very rare genotypes of UGT1A1 gene: (TA)(5/7) and c.-64G>C heterozygotes. Conclusions UGT1A1 gene polymorphism and as its consequence of high serum bilirubin level may promote iron accumulation in hemochromatosis patients by reducing the activity of inflammation. We proposed a possible mechanism of this interaction.

Host genetic background affects the course of infection and treatment response in patients with chronic hepatitis B.

BACKGROUND: Hepatitis B virus (HBV) utilizes proteins encoded by the host to infect hepatocytes and replicate. Recently, several novel host factors have been identified and described as important to the HBV lifecycle. The influence of host genetic background on chronic hepatitis B (CHB) pathogenesis is still poorly understood. OBJECTIVES: Here, we aimed to investigate the association of NTCP, FXRα, HNF1α, HNF4α, and TDP2 genetic polymorphisms with the natural course of CHB and antiviral treatment response. STUDY DESIGN: We genotyped 18 single-nucleotide polymorphisms using MALDI-TOF mass spectrometry in 136 patients with CHB and 100 healthy individuals. We investigated associations of the selected polymorphisms with biochemical, serological and hepatic markers of disease progression and treatment response. RESULTS: No significant differences in genotypic or allelic distribution between CHB and control groups were observed. Within TDP2, rs3087943 variations were associated with treatment response, and rs1047782 modified the risk of advanced liver inflammation. Rs7154439 within NTCP was associated with HBeAg seroconversion after 48 weeks of nucleos(t)ide analogue treatment. HNF1α genotypes were associated with treatment response, liver damage and baseline HBeAg presence. HNF4α rs1800961 predicted PEG-IFNα treatment-induced HBsAg clearance in long-term follow up. CONCLUSIONS: This study indicates host genetic background relevance in the course of CHB and confirms the role of recently described genes for HBV infection. The obtained results might serve as a starting point for validation studies on the clinical application of selected genetic variants to predict individual risks of CHB-induced liver failure and treatment response.

TNF-α polymorphisms affect persistence and progression of HBV infection.

BACKGROUND: Hepatitis B virus (HBV) infections are a major threat worldwide. Disease progression and outcome is diverse and depends on host genetic background. Recently, a high rate of HBV reactivation in individuals receiving tumor necrosis factor-α (TNF-α) antagonists showed the importance of this cytokine in HBV infection control. Here, we investigated the influence of TNF-α promoter polymorphisms on susceptibility to chronic HBV infection (CHB), liver injury progression and outcomes. METHODS: A total of 231 patients with CHB constituted the study group and 100 healthy volunteers-the local control group. TNF-α -1031T/C, -863C/A, -857C/T, -308G/A, and -238G/A were genotyped using MALDI-TOF mass spectrometry. RESULTS: TNF-α -1031C and -863A alleles were observed more frequently in CHB group than in healthy controls. Carriers of TNF-α -1031C and -863A variant alleles had lower baseline levels of serum HBV DNA and lower liver necroinflammatory activity than dominant homozygotes. A -857CT genotype predisposed to higher necroinflammatory activity. No associations between TNF-α variants and liver fibrosis were found. CONCLUSION: This study indicates that TNF-α -863A and -1031C alleles are associated with increased susceptibility to CHB in individuals from northern Poland. The same variants determine the course of CHB, lowering viremia and reducing necroinflammatory activity of the liver.