Effect of cytokine gene polymorphism on histological activity index, viral load and response to treatment in patients with chronic hepatitis C genotype 3

TNFA -308G>A and IL10 -1082A>G polymorphisms seem to be predictive biomarkers of chronic HCV infection

Background

Genetic changes may induce dysregulated cytokine production and affect the progression of the chronic disease caused by the hepacivirus C (HCV) because the balance of pro- and anti-inflammatory cytokines determines the outcome of infection. This study evaluated the TNFA -308G>A and IL10 -1082A>G polymorphisms in the susceptibility and progress of chronic hepatitis C.

Method

The study included 101 samples from patients with chronic hepatitis C and 300 samples from healthy donors. Polymorphisms were typed by real-time PCR and were analyzed for associations with histopathological parameters (according to METAVIR classification) and HCV viral load.

Results

The polymorphic genotype for the TNFA -308G>A variant was not present in the group of patients with chronic hepatitis C and its absence could be associated with protection against HCV infection (p = 0.0477). Patients with the polymorphic genotype of the IL10 -1082A>G polymorphism had higher HCV viral load than wild-type patients (p = 0.0428). Neither polymorphism was associated with different levels of necroinflammatory activity or fibrosis scores.

Conclusion

Our results suggest the polymorphic genotype at TNFA -308G>A as protective against chronic HCV infection, and the polymorphic genotype at the IL10 -1082A>G variant associated with higher HCV viral load. Further studies must be performed in order to confirm these associations.

The Impact of Interferon-γ (IFN-γ) and IFN-γ-Inducible Protein 10 (IP-10) Genes' Polymorphism on Risk of Hepatitis C Virus-Related Liver Cirrhosis

Background: Today there is increasing evidence concerning the association between individual genetic polymorphisms within proinflammatory cytokines and chronic hepatitis C (CHC) severity. It has been demonstrated that polymorphisms in some genes may significantly predict HCV infected patients' susceptibility to developing liver cirrhosis or their responsiveness to the treatment.Aim: We investigated the influence of single nucleotide polymorphisms (SNPs) in Interferon (IFN-γ) and Interferon Gamma-Inducible Protein 10 (IP-10) genes on cirrhosis risk in HCV-infected patients and their association with response to various direct-acting antiviral drugs (DAAs).Methods: IFN-γ (+874T/A, +2109A/G) and IP-10 (-135G/A, -1447A/G) genotypes were determined in 175 CHC Egyptian HCV patients (69 liver cirrhotic and 106 non-cirrhotic patients) using either single-stranded polymorphism polymerase chain reaction (SSP-PCR) or Restriction fragment length-PCR (RFLP-PCR) methods.Results: IFN-γ + 874 TA, IP-10 - 135AA, and IP-10 - 1447AA and IP-10 - 1447GG genotypes are increased in patients developing liver cirrhosis compared to non-cirrhotic ones. Although, no statistical significance in their distribution was demonstrated, indicating the lack of association between these SNPs and liver cirrhosis susceptibility in HCV-infected patients. Haplotypes analysis between different loci on all selected genes showed a significant increase in AGGA and TAGA and a significant decrease in TGGA haplotypes in cirrhotic patients. Genotype frequencies at loci -135 and -1447 of IP-10 appeared to be in complete Linkage disequilibrium (LD) (D' = 0.999, r² = 0.689).Conclusion: Our data support the concept that IFN-γ and IP-10 gene polymorphisms are not predictors of disease progression among Egyptian patients with HCV infection.

Association of cytokine gene polymorphisms with chronic hepatitis C virus genotype 1b infection in Chinese Han population: An observational study

Cytokines are extensively involved in the process of hepatitis C virus (HCV) infection and take a crucial part in host immune regulation. We aimed to explore the potential correlation of cytokine single nucleotide polymorphisms (SNPs) with HCV susceptibility and response rate of interferon (IFN)-based antiviral therapy in Chinese Han population.A case-control genetic association study was conducted between 198 patients with chronic HCV genotype 1b infection and 142 healthy controls. Genetic polymorphisms of TNF-α (rs1800629), TGF-β (rs1800469), IL-10 (rs1800896, rs1800871, and rs1800872), IL-6 (rs1800795, rs1800796), IFN-γ (rs2430561), and IL-28B (rs12979860, rs12980275, and rs8099917) were analyzed by MassARRAY SNP technology. Patients were treated with IFNα-2b or pegylated-IFNα-2a plus ribavirin for 48 weeks. Sustained virological response (SVR) was assessed 6 months after the completion of the treatment.The IL-28B rs12979860-CC (odds ratio [OR] = 4.35, 95% confidence interval [CI]: 1.69-11.21, P = .001), rs12980275-AA (OR = 3.41, 95% CI: 1.08-10.76, P = .028), and rs8099917-TT (OR = 3.86, 95% CI: 1.49-10.12, P = .004) were significantly associated with SVR, and IL-10 rs1800871-TT (OR = .50, 95% CI: 0.25-1.00, P = .049) and rs1800872-AA (OR = .50, 95% CI: 0.25-1.00, P = .049) were also significant for SVR. No association was found between the cytokine SNPs and HCV susceptibility. Additionally, multivariate analysis showed that low baseline viral load (OR = 3.63, 95% CI: 1.01-13.02, P = .048), pegylated-IFN (OR = 9.68, 95% CI: 1.14-82.13, P = .037) and rs12979860-CC (OR = 6.08, 95% CI: 2.00-18.46, P = .001) were independent factors for SVR.IL-28 and IL-10 gene polymorphisms played an important role in predicting host response to IFN-based antiviral therapy in HCV genotype 1b infection.

Cellular crosstalk mediated by platelet-derived growth factor BB and transforming growth factor β during hepatic injury activates hepatic stellate cells

Apoptotic hepatocytes release factors that activate hepatic stellate cells (HSCs), thereby inducing hepatic fibrosis. In the present study, in vivo and in vitro injury models were established using acetaminophen, ethanol, carbon tetrachloride, or thioacetamide. Histology of hepatotoxicant-induced diseased hepatic tissue correlated with differential expression of fibrosis-related genes. A marked increase in co-staining of transforming growth factor β receptor type II (TGFRIIβ) – desmin or α-smooth muscle actin – platelet-derived growth factor receptor β (PDGFRβ), markers of activated HSCs, in liver sections of these hepatotoxicant-treated mice also depicted an increase in Annexin V – cytokeratin expressing hepatocytes. To understand the molecular mechanisms of disease pathology, in vitro experiments were designed using the conditioned medium (CM) of hepatotoxicant-treated HepG2 cells supplemented to HSCs. A significant increase in HSC proliferation, migration, and expression of fibrosis-related genes and protein was observed, thereby suggesting the characteristics of an activated phenotype. Treating HepG2 cells with hepatotoxicants resulted in a significant increase in mRNA expression of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β (TGFβ). CM supplemented to HSCs resulted in increased phosphorylation of PDGFRβ and TGFRIIβ along with its downstream effectors, extracellular signal-related kinase 1/2 and focal adhesion kinase. Neutralizing antibodies against PDGF-BB and TGFβ effectively perturbed the hepatotoxicant-treated HepG2 cell CM-induced activation of HSCs. This study suggests PDGF-BB and TGFβ as potential molecular targets for developing anti-fibrotic therapeutics.

Interleukin-10 and Interferon Gamma Gene Polymorphisms and Hepatitis C Virus-Related Liver Cirrhosis Risk

The aim of the study was to evaluate the association between the gene polymorphisms in interleukin-10 (IL-10) and interferon gamma (IFN-γ) genes with susceptibility and severity of hepatitis C virus (HCV) infection among Egyptian patients. Interleukin-10 -592 A/C, -1082 G/A and IFN-γ +874 T/A genotypes were determined in 100 chronic HCV patients and 50 healthy controls using restriction fragment length polymorphism (RFLP) and the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) respectively. IL-10 -592 A/C polymorphism genotyping revealed that the frequency of CC genotype was significantly higher in chronic HCV patients than in controls (58% versus 30%, P < 0.05). Regarding IL-10 -1082 G/A polymorphism genotyping, a higher frequency of GG genotype was found in chronic HCV patients compared to controls (31% versus 10%, P < 0.05). IFN-γ +874 T/A genotyping showed that TT genotype was significantly higher in chronic HCV participants than controls (31% versus 18%, P < 0.05), while a higher frequency of T allele was found in cirrhotic patients compared to noncirrhotic patients (P < 0.05). Our observations suggested that IL-10 -592 A/C, -1082 G/A, and IFN-γ +874 T/A polymorphisms had a strong association with susceptibility to HCV infection. However, no significant association was observed between the cytokines (IL-10 and IFN-γ) genotypes profile and HCV-liver cirrhosis risk in the studied population, except for the high frequency of IFN-γ +874 T allele in cirrhotic patients.

Association of TNF-alpha (-308 A/G) and IFN-gamma (+874 A/T) gene polymorphisms in response to spontaneous and treatment induced viral clearance in HCV infected multitransfused thalassemic patients

BACKGROUND

Multitransfused thalassemic individuals are at high risk of developing transfusion transmitted Hepatitis C virus (HCV) infection. The aim of the study was to correlate the effects of host cytokine single nucleotide polymorphisms of TNF-α (-308 A/G) and IFN-γ (+874 A/T) in spontaneous or IFN induced treatment response in the HCV infected thalassemic individuals.

METHODS

A total of 427 HCV sero-reactive thalassemic individuals were processed for HCV viral genomic diversity and host gene polymorphisms analysis of TNF-α (-308 A/G) and IFN-γ (+874 A/T).

RESULTS

Out of 427 HCV sero-reactive individuals, 69.09% were found to be HCV RNA positive with genotype 3 as the predominant infecting strain (94.29%). Study highlighted that, A allele was significantly associated with (p < .05) spontaneous clearance of HCV infection and G allele was correlated with viral persistence at TNF-α (-308) gene polymorphism. Whereas in case of IFN-γ (+874) SNPs, A allele was significantly responsible (p < .05) for spontaneous clearance than T allele. Our study also indicated that in relapsed cases, IFN-γ (+874) T allele is more responsible than A allele. Though no significant correlation was found at both TNF-α (-308) and IFN-γ (+874) gene polymorphism among SVR and relapsed thalassemic patients.

CONCLUSION

A allele at both TNF-α (-308) and IFN-γ (+874) were strongly associated with spontaneous clearance among this population. But in case of SVR and relapsed cases no significant association was found. This cytokine gene polymorphisms pattern will help clinicians to take an informed decision about therapeutic management of HCV infected thalassemic individuals.

Osteopontin as a marker for response to pegylated interferon Alpha-2b treatment in Chronic HCV Saudi patients

BACKGROUND

Many recent studies support the idea that osteopontin (OPN) can be used to predict the success of pegylated interferon (PEG IFN) alpha-2b/ribavirin therapy in chronic HCV patients.

OBJECTIVE

Our aim was to investigate the role of plasma OPN and its gene polymorphism at nt - 443 in response to PEG IFN in Saudi patients with chronic HCV.

METHODS

Blood was collected from 87 patients with chronic hepatitis C before treatment, then patients received PEG IFN α2b plus ribavirin combination therapy. Another 25 healthy subjects, matched for age and sex to patients, were enrolled as controls. Single nucleotide polymorphism (SNP) in OPN at nt - 443 and its blood level were analyzed.

RESULTS

The frequency of patients who reached sustained virological response (SVR) was increased in patients with T/T at nt - 443 than in those with C/C or C/T. Also the frequency of T allele was increased in responders than in non-responders. However, this increase was not statistically significant. The blood level of OPN was significantly increased in non-responders (Mean±SD=37.21±3.9) in comparison to responders (Mean±SD=33.22±4.1).

CONCLUSION

Osteopontin blood level can be considered as a reliable predictor to PEG IFN α2b plus ribavirin therapy in chronic HCV Saudi Patients.

A systematic review of treatment response rates in Pakistani hepatitis C virus patients; current prospects and future challenges

BACKGROUND

The estimated hepatitis C virus (HCV) carriers are approximately 10 million in Pakistan which usually progresses to chronic hepatitis, with rare cases of spontaneous viral eradication. The present article reviews the treatment status of HCV infection in Pakistani population and various factors associated with the treatment response rates.

METHODS

Literature on anti-HCV therapy was searched in PubMed, Google Scholar and PakMediNet. Thirty three different studies representing different geographic regions of Pakistan published from 2002 to 2016 were included in the present review. Weighted mean, standard error estimates (SE) and standard deviation (SD) were determined for each population group.

RESULTS

Mean value for sustained virological response (SVR) for standard IFN plus ribavirin (RBV) combination therapy was 68.38% ± 14.13% (range 33.8%-87.10%; SE 3.08) and pegylated-IFN plus RBV combination therapy 64.38% ± 8.68% (range 55.0%-76.00%; SE 3.88). The lowest value for SVR has been reported to be 24.3% (for genotype 1; administering INF-α 2b 3MU 3 times/week and RBV 1000-1200 mg/day for 48 weeks) while highest of 87.5% (genotype 3a; INF-α 2a 3MU 3 times/week and RBV 1000-1200 mg/day for 24 weeks). The mean value for rapid virological response (RVR) was found to be 48.18% ± 29.20% (SE 9.73). As PEG-interferon and direct acting antivirals (DAAs) are relatively expensive, interferon-alfa (IFN-α) and RBV combination therapy have been used widely to treat HCV infected patients in Pakistan for the last one and half decade. On average, 2.45% of the patients discontinued treatment due to severe side effects.

CONCLUSION

We encourage further studies on understanding host and viral factors associated with specific focus on harder to treat viral variants (relapsers and nonresponders). These variants are currently rising in the country.

Cell death mechanisms in human chronic liver diseases: a far cry from clinical applicability

The liver is constantly exposed to a host of injurious stimuli. This results in hepatocellular death mainly by apoptosis and necrosis, but also due to autophagy, necroptosis, pyroptosis and in some cases by an intricately balanced combination thereof. Overwhelming and continuous cell death in the liver leads to inflammation, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Although data from various disease models may suggest a specific (predominant) cell death mode for different aetiologies, the clinical reality is not as clear cut. Reliable and non-invasive cell death markers are not available in general practice and assessment of cell death mode to absolute certainty from liver biopsies does not seem feasible, yet. Various aetiologies probably induce different predominant cell death modes within the liver, although the death modes involved may change during disease progression. Moreover, current methods applicable in patients are limited to surrogate markers for apoptosis (M30), and possibly for pyroptosis (IL-1 family) and necro(pto)sis (HMGB1). Although markers for some death modes are not available at all (autophagy), others may not be specific for a cell death mode or might not always definitely indicate dying cells. Physicians need to take care in asserting the presence of cell death. Still the serum-derived markers are valuable tools to assess severity of chronic liver diseases. This review gives a short overview of known hepatocellular cell death modes in various aetiologies of chronic liver disease. Also the limitations of current knowledge in human settings and utilization of surrogate markers for disease assessment are summarized.

Interleukin 10 gene single nucleotide polymorphisms in Polish patients with chronic hepatitis C: Analysis of association with severity of disease and treatment outcome

It is suggested that interleukin 10 (IL-10), as a modulator of immune response, is likely to influence the elimination of hepatitis C virus (HCV), the progression of chronic hepatitis C (CHC) and the response to interferon-based therapy in CHC patients. The aim of the study was to analyze the association of single nucleotide polymorphisms (SNPs) of IL-10 gene with severity of liver disease (degree of inflammation and stage of fibrosis) and outcome of pegylated interferon alpha and ribavirin combined therapy (sustained virological response (SVR) and relapse) in 196 Polish CHC patients infected with HCV genotype 1. The analysis included IL-10 promoter SNPs: -1082(A/G) rs1800896, -819(C/T) rs1800871, -592(C/A) rs1800872 and SNP in the 3' UTR of IL-10 gene: +4529(A/G) rs3024498. Genotyping was performed using PCR-RFLP and HRM analysis. It was demonstrated that the -592C allele is associated with mild hepatic inflammation. Moreover, it was found that the -819C allele might be associated with SVR and that the ACCA haplotype and intermediate IL-10 producer ACC haplotype are associated with SVR and non-relapse. It can be concluded that IL-10 SNPs are associated with severity of disease and response to therapy and may be considered as potential prognostic and predictive markers in CHC.

Interleukin-10.rs1800896 and Interleukin-18.rs1946518 gene polymorphisms could not predict the outcome of hepatitis C virus infection in Egyptian patients treated with pegylated interferon plus ribavirin

A single-nucleotide polymorphism (SNP) in the interleukin (IL)-28B gene was used as a major predictor of the response to treatment in patients with hepatitis C virus (HCV) infection. Data examining the role of IL-10 and IL-18 gene polymorphisms among HCV genotype 4 (G4)-infected Egyptians in response to pegylated interferon (PEG-IFN) plus ribavirin (RBV) therapy are limited. This study investigated the impact of SNP at IL-10.rs1800896 (at position -1082) and IL-18.rs1946518 genes (at position -607) on the response to PEG-IFN/RBV therapy in HCV-infected Egyptians. This study was carried out on 100 HCV patients treated with PEG-IFN plus RBV and 100 healthy controls. The HCV patients included 50 treatment non-responders (NR) and 50 subjects with sustained virologic response (SVR). Genomic DNA from venous blood of subjects was extracted and IL-10.rs1800896 and IL-18.rs1946518 genotypes were determined using allele-specific amplification and SYBR Green real-time PCR. Linkage disequilibrium between the two SNPs was estimated using Haploview software. The frequency of the IL-10.rs1800896 AA, AG and GG genotypes among non-responders were 16 %, 70 % and 14 % while among SVR subjects, the frequency was 34 %, 60 % and 6 %, respectively (p=0.073). On the other hand, the frequency of the IL-18.rs1946518 AA, AC and CC genotypes among non-responders was 14 %, 50 % and 36 %, respectively, while among responders, these frequencies were 28 %, 44 % and 28 %, (p = 0.220). Both markers were in linkage equilibrium (D' = 0.23; r (2) = 0.052). SNPs in the IL-10.rs1800896 and IL-18.rs1946518 genes could not predict the outcome of HCV infection in Egyptians treated with PEG-IFN/RBV.

Influence of cytokine and cytokine receptor gene polymorphisms on the degree of liver damage in patients with chronic hepatitis C

Hepatic fibrosis may be the result of repetitive injury to hepatocytes caused by HCV infection and the immune response to it. Cytokines regulate the inflammatory response to injury and modulate hepatic fibrogenesis. Single nucleotide polymorphisms (SNPs) located in cytokine genes may influence the cytokine expression and secretion that may contribute to hepatic fibrogenesis in HCV infection. The aim of this study was to determine the genotype of 22 SNPs found in the genes of 13 cytokines/cytokine receptors to assess the influence of polymorphic variants on the stage of liver damage in Brazilian patients chronically infected with HCV genotype 1 only. 141 unrelated patients were grouped according to their stage of fibrosis: absence of fibrosis or patients in the initial stages of fibrosis (F0-F2, n = 84), patients with advanced stages of fibrosis or cirrhosis (F3-F4, n = 57), without cirrhosis (F0-F3, n = 103), and with cirrhosis (F4, n = 38). The comparison of frequencies in each sub-sample was performed by 2 × 2 contingency tables using the chi-square or Fisher's exact test. Stepwise logistic regression was also used to assess independent associations between cirrhosis or fibrosis with polymorphic variants. The TNFA-308G:A genotype conferred increased risk of fibrosis and cirrhosis. The TNFA-238G:G genotype was associated with protection from cirrhosis. The IL10-819C:T genotype conferred protection from fibrosis and the IL1B-511C:T genotype conferred increased risk of cirrhosis. Some of these genotypes showed results on the borderline of statistical significance in the bivariate analysis. We conclude that gene variants of cytokines/receptors may influence liver damage in patients chronically infected by HCV genotype 1.

Interferon-γ and Interleukin-10 Gene Polymorphisms are not Predictors of Chronic Hepatitis C (Genotype-4) Disease Progression

Immunoregulatory cytokines have an influence on hepatitis C virus (HCV) infection outcome. This study aimed to determine whether single nucleotide polymorphisms (SNP) in IFN- γ and IL-10 genes are associated with susceptibility and/or are markers of prognosis regarding chronic hepatitis C outcomes. IFN γ (+874T/A) and IL-10 (-1082G/A) genotypes were determined in 75 HCV genotype 4 patients with different disease severities (chronic hepatitis, n=25, liver cirrhosis and hepatocellular carcinoma (HCC) on top of liver cirrhosis, n=50) and 25 healthy participants using allele-specific polymerase chain reaction. No statistical differences in allele or genotype distributions of IFN γ and IL-10 genes were detected between patients and controls or between patientgroups. No significant difference in the frequency of IL-10 SNP at position -1082 or IFN-γ at position +874T/A was found between chronic HCV genotype 4 and with progression of disease severity in liver cirrhosis or HCC. In conclusion; interferon-γ and interleukin-10 gene polymorphisms are not predictors of disease progression in patients with chronic hepatitis C (Genotype-4).

Influence of Polymorphism (-G308A) TNF-α on the Periportal Fibrosis Regression of Schistosomiasis After Specific Treatment

AIMS

Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine and important mediator of severity for periportal fibrosis (PPF). We hypothesized that the (-G380A) polymorphism in the TNF-α gene is associated with regression of PPF after treatment for schistosomiasis mansoni.

METHODS

This is a retrospective cohort study, involving 124 Brazilian patients infected with Schistosoma mansoni, who were followed for 2 years after treatment to estimate the likelihood of PPF regression. Sociodemographic and clinical factors were also identified, with emphasis on specific treatment.

RESULTS

No statistical difference was observed between sociodemographic and clinical factors among the exposed groups. Genotypes (-308) GA/AA were positively associated with the degree of PFF regression (relative risk [RR] = 0.52; ρ = 0.025), as well as in the image pattern of PPF (RR = 0.56; ρ = 0.048), when compared with the genotype (-308) GG. There was no statistical difference in TNF-α serum levels between the exposed groups.

CONCLUSIONS

These results suggest that the (-G308A) polymorphism of the TNF-α gene may be one of the factors that prevents the regression of the degree and pattern of PPF in the Brazilian population, and thus it may potentially be a predictive factor of PPF intensity in schistosomiasis.

The Impact of IFN-γ Gene Polymorphisms on Spontaneous Clearance of HCV Infection in Fars Province, Southern of Iran

BACKGROUND

Certain polymorphisms in cytokine genes such as IFN-γ may influence the outcome of hepatitis C virus (HCV) infection. Here the frequency of the genotype, allele, and haplotype of IFN-γ gene at some loci is investigated in HCV-infected patients.

METHODS

Totally 255 patients with chronic HCV infection and 44 spontaneously cleared individuals were included. The chronic or clearance states were confirmed using enzyme-linked immunosorbent assay (ELISA) and two different qualitative reverse transcriptase polymerase chain reaction (RT-PCR) techniques. IFN-γ gene polymorphisms were performed by PCR using sequence-specific primers and PCR-RLFP on extracted genomic DNA.

RESULTS

The frequency of GG genotype (P = 0.0001, OR: 5.69 and CI: 2.21-14.62) and allele (P = 0.0003, OR: 2.73 and CI: 1.54-4.83) of IFN-γ gene at +2109 locus was significantly higher in cases that spontaneously cleared the infection. Haplotype analysis showed the association of AG haplotype (P = 0.0046, OR = 6.14 and CI = 1.56-25) with spontaneous clearance of the infection.

CONCLUSION

Our finding indicated that individuals with GG genotype at +2109 loci of IFN-γ gene and also AG haplotype (A allele at +874 loci and G allele at +2109 loci) may clear HCV infection more frequently than those with AA and AG genotype at +2109 loci and AA, TA, and TG haplotype.

Polymorphisms of IL-10 gene in patients infected with HCV under antiviral treatment in southern Brazil

Interleukin-10 (IL-10) is a cytokine that plays an important role in the regulation of the immune system. Gene polymorphisms of IL-10 have been associated with the different expression levels of this cytokine. In hepatitis C virus infection, IL-10 appears to interfere with the progression of disease, viral persistence and the response to therapy. This study investigated genetic variability in the IL-10 gene promoter between patients infected with hepatitis C virus (HCV) and healthy individuals, associating the frequency of polymorphisms with different aspects of viral infection. This is a case-control study with 260 patients who were infected with HCV and 260 healthy individuals. Genotyping of the polymorphisms was performed using the technique of amplification refractory mutation system PCR (ARMS-PCR) for regions of the IL-10 gene promoter (-1082 G/A, -819 C/T, -592 C/A). The frequencies of alleles and genotypes related to polymorphisms in the IL-10 gene promoter showed a higher frequency of the G allele and genotype GG in the -1082 region between the infected group and the control group (p=0.005 and p=0.001, respectively), whereas the AA genotype was significantly more frequent in the control group. The frequencies of the haplotypes GTA and GCC were higher in the group of infected individuals, whereas the haplotype ATA was more frequent in the healthy group (p<0.006). It was also observed that the genotypes GG and AG in the region -1082 were significantly more frequent among patients infected with HCV who were in advanced stages of fibrosis and cirrhosis (p=0.042). No association was observed between polymorphisms of IL-10 and sustained virologic response (SVR).

Influence of IL10 gene polymorphisms on the severity of liver fibrosis and susceptibility to liver cirrhosis in HBV/HCV-infected patients

BACKGROUND

Previous studies about the association of the interleukin-10 (IL-10) polymorphisms with the progression of liver fibrosis or cirrhosis susceptibility in chronic hepatitis B/C (CHB/C) disease were inconsistent. The aim of this meta-analysis was to derive a more precise estimation of the association.

METHODS

We searched Medline, PubMed, EMBASE and Web of Science electronic databases using the following key words: liver fibrosis/cirrhosis, IL10, and polymorphism. Statistical analyses were performed by STATA11.0 software, with odds ratios (ORs) and their 95% confidence intervals (CIs).

RESULTS

12 independent studies in relation to IL10-1082A/G, -819C/T and -592C/A polymorphisms were included in our study, which consisted of 197 moderate/severe liver fibrosis cases and 426 mild fibrosis controls as well as 536 liver cirrhosis cases and 881 non-cirrhosis controls. The results indicated that a significantly decreased risk of moderate/severe fibrosis was associated with the GCC haplotype (IL10-1082G, -819C and -592C) in the overall CHB/C patients (OR: 0.547, 95% CI: 0.317-0.946, P=0.031). We did not detect any significant association between these polymorphisms and liver cirrhosis susceptibility in the total population or a subgroup of Asians. However, subgroup analyses by different aetiologies showed that the -819T heterozygotes (TC) were associated with a significantly increased risk of HCV-related liver cirrhosis in the Japanese population (OR: 1.254, 95% CI: 1.033-1.522, P=0.022).

CONCLUSIONS

The putative high IL-10 production haplotype GCC is more likely to be associated with less severe liver fibrosis in CHB/C patients. Additionally, the IL10-819T allele may be a susceptible factor for HCV-related liver cirrhosis in the Japanese population.

Combined impact of hepatitis C virus genotype 1 and interleukin-6 and tumor necrosis factor-α polymorphisms on serum levels of pro-inflammatory cytokines in Brazilian HCV-infected patients

We investigated the association between hepatitis C virus (HCV) genotypes and host cytokine gene polymorphisms and serum cytokine levels in patients with chronic hepatitis C. Serum IL-6, TNF-α, IL-2, IFN-γ, IL-4, IL-10, and IL-17A levels were measured in 67 HCV patients (68.2% genotype 1 [G1]) and 47 healthy controls. The HCV patients had higher IL-6, IL-2, IFN-γ, IL-10, and IL-17A levels than the controls. HCV G1 patients had higher IL-2 and IFN-γ levels than G2 patients. The -174IL6G>C, -308TNFαG>A, and -1082IL10A>G variants were similarly distributed in both groups. However, HCV patients with the -174IL6GC variant had higher IL-2 and IFN-γ levels than patients with the GG and CC variants. Additionally, HCV patients with the -308TNFαGG genotype had higher IL-17A levels than patients with the AG genotype, whereas patients with the -1082IL10GG variant had higher IL-6 levels than patients with the AA and AG variants. A significant proportion of HCV patients had high levels of both IL-2 and IFN-γ. The subgroup of HCV patients with the G1/IL6CG/TNFαGG association displayed the highest proportions of high producers of IL-2 and IFN-γ whereas the subgroup with the G1/TNFαGG profile showed high proportions of high producers of IL-6 and IL-17A. HCV patients with other HCV/cytokine genotype associations showed no particular cytokine profile. Our results suggest that HCV genotype G1 and IL-6 and TNF-α polymorphisms have a clinically relevant influence on serum pro-inflammatory cytokine profile (IL-2 and IFN-γ) in HCV patients.

Haplotype analysis of interleukin-10 gene promoter polymorphisms in chronic hepatitis C infection: a case control study

High prevalence of hepatitis c virus (HCV) infection in some areas necessitates more investigations of the causative factors. Genetic factors that cause disruption in operation or secretion of interleukin 10 (IL-10), an anti-inflammatory cytokine, may play a role in the intensity of the disease. The aim of this study was to evaluate genetic variants of IL-10 gene polymorphisms in HCV patients and their relationship with HCV disease. Fifty HCV patients and the same number of healthy individuals who were referred to hepatitis clinic in Mashhad, northeast of Iran, were recruited. Genomic DNA was extracted from whole blood. Genotyping for IL-10 gene promoter polymorphisms in three positions (-1082 G>A, -819 C>T and -592 C>A) was conducted by amplification refractory mutation system-polymerase chain reaction. Haplotype analysis was performed using PHASE software. In a recessive analysis model of the -1082 position (GG vs. AA+AG), GG genotype was more common in patients (adjusted p = 0.02; OR = 4.66 [95% CI 1.31-16.35]). Also, ATA haplotype was more prevalent in HCV patients (adjusted p = 0.061; OR = 1.87 [95% CI 0.97-3.61]). Also, ATC/GCA diplotypes were more common in controls (adjusted p=0.002; adjusted OR = 0.27 [95% CI 0.11-0.63]). Although we found a possible association between IL-10 promoter polymorphisms and HCV infection, certain genotypes or diplotypes may confer a higher risk or susceptibility for developing HCV infection.

Association of interferon gamma gene polymorphisms with BK virus infection among Hispanic renal allograft recipients

BACKGROUND

BK virus nephropathy is one of the most common viral infections that affect up to 10% of renal transplant recipients (RTRs), causing allograft dysfunction and graft loss. Interferon-gamma (IFN-γ) gene polymorphisms have been associated with parvovirus B19, hepatitis C virus, HIV-1/AIDS infection, cytomegalovirus viremia, and disease. IFN-γ is known to have potent inhibitory effects on BK virus gene expression, both at the level of transcription and translation.

METHODS

It was investigated whether IFN-γ polymorphisms are associated with BKV infection. Genotyping of four single-nucleotide polymorphisms located in the IFN-γ gene were performed on DNA collected from a total of 251 RTRs (71 RTRs with BKV infection and 180 without BKV infection).

RESULTS

Analysis of the results showed that IFN-γ (rs12369470) CC genotype was significantly associated with susceptibility to BKV infection (OR: 2.9, 95% CI: 1.29-6.44, P=0.007) while the IFN-γ +874 (rs2435061) TT and (rs2406918) CC genotypes appear to be markers for protection against BKV infection (OR: 0.29, 95% CI: 0.1-0.83, P=0.01 for rs245061; OR: 0.61, 95% CI: 0.4-0.94, P=0.02 for rs24069718). A haplotype analysis using the combination of rs2435061-rs2406918-rs2870953 showed that the A-G-T haplotype was associated with a significantly reduced risk for BKV infection (OR: 0.43, 95% CI: 0.25-0.73, P=0.001).

CONCLUSION

Polymorphisms in the IFN-γ gene may confer certain protection or predisposition for BKV infection.

Molecular mechanisms of liver injury: apoptosis or necrosis

Hepatic apoptosis is thought of as a prevalent mechanism in most forms of liver injury. However, the role of hepatic apoptosis is often intermixed with the cellular necrosis. It remains unknown how apoptosis is relevant to the progression of the liver injury. This review summarizes the characteristics of both hepatic apoptosis and necrosis in pathogenesis of liver diseases. Apoptosis and necrosis represent alternative outcomes of different etiology during liver injury. Apoptosis is a main mode of cell death in chronic viral hepatitis, but is intermingled with necrosis in cholestatic livers. Necrosis is the principal type of liver cell killing in acetaminophen-induced hepatotoxicity. Anti-apoptosis as a strategy is beneficial to liver repair response. Therapeutic options of liver disease depend on the understanding toward pathogenic mechanisms of different etiology.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

Molecular mechanisms of hepatic apoptosis

Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis.

Molecular mechanisms of hepatic apoptosis

Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis.

Variations at multiple genes improve interleukin 28B genotype predictive capacity for response to therapy against hepatitis C infection

OBJECTIVE

To identify genetic factors that predict sustained virological response (SVR) to pegylated interferon (Peg-IFN)/ribavirin (RBV) in HIV/hepatitis C virus (HCV) genotype 1 or 4-coinfected patients and that enhance the predictive capacity of IL28B genotype in this population.

DESIGN

Prospective cohort study.

SETTING

Five tertiary care centers in Spain.

PATIENTS

Two hundred and five HIV/HCV genotype 1 or 4-coinfected patients who received a complete course of Peg-IFN/RBV for 48 weeks.

MAIN OUTCOME MEASURES

All individuals were genotyped for 144 single-nucleotide polymorphisms (SNPs).

RESULTS

One hundred and sixty-two (79%) patients bore HCV genotype 1. Overall SVR was achieved by 73 (36%) individuals. SNPs at the following genes were associated with SVR: IL28B, low-density lipoprotein receptor (LDLR), transforming growth factor β (TGF-β), aquaporine 2 (AQP-2), very-low-density lipoprotein receptor, Sp110 nuclear body protein, interferon alpha/beta receptor 1, 2'-5'-oligoadenylate synthase 1 and apolipoprotein B. There was a strong synergy between SNPs at IL28B, TGF-β and AQP-2 genes: the number of patients reaching SVR with all three favorable genotypes versus unfavorable genotypes were 22 (78.6%) versus 1 (7.1%) (P = 2.1 × 10). HCV baseline viral load, IL28B, TGF-β, AQP-2 and LDLR haplotypes were independently associated with SVR.

CONCLUSION

A number of genetic factors modify the predictive capacity of IL28B genotype. These can be used to identify HCV genotype 1 or 4-infected patients with a very high or a very low probability to respond to bitherapy with Peg-IFN/RBV. Predictive models based on these factors could be helpful to tailor direct acting antiviral-based therapy.

Influence of Genetic Polymorphisms of Tumor Necrosis Factor Alpha and Interleukin 10 Genes on the Risk of Liver Cirrhosis in HIV-HCV Coinfected Patients

OBJECTIVE

Analysis of the contribution of genetic (single nucleotide polymorphisms (SNP) at position -238 and -308 of the tumor necrosis factor alpha (TNF-α) and -592 of the interleukin-10 (IL-10) promotor genes) and of classical factors (age, alcohol, immunodepression, antirretroviral therapy) on the risk of liver cirrhosis in human immunodeficiency (HIV)-hepatitis C (HCV) virus coinfected patients.

PATIENTS AND METHODS

Ninety one HIV-HCV coinfected patients (50 of them with chronic hepatitis and 41 with liver cirrhosis) and 55 healthy controls were studied. Demographic, risk factors for the HIV-HCV infection, HIV-related (CD4+ T cell count, antiretroviral therapy, HIV viral load) and HCV-related (serum ALT concentration, HCV viral load, HCV genotype) characteristics and polymorphisms at position -238 and -308 of the tumor necrosis factor alfa (TNF- α) and -592 of the interleukin-10 (IL-10) promotor genes were studied.

RESULTS

Evolution time of the infection was 21 years in both patients' groups (chronic hepatitis and liver cirrhosis). The group of patients with liver cirrhosis shows a lower CD4+ T cell count at the inclusion in the study (but not at diagnosis of HIV infection), a higher percentage of individuals with previous alcohol abuse, and a higher proportion of patients with the genotype GG at position -238 of the TNF-α promotor gene; polymorphism at -592 of the IL-10 promotor gene approaches to statistical significance. Serum concentrations of profibrogenic transforming growth factor beta1 were significantly higher in healthy controls with genotype GG at -238 TNF-α promotor gene. The linear regression analysis demonstrates that the genotype GG at -238 TNF-α promotor gene was the independent factor associated to liver cirrhosis.

CONCLUSION

It is stressed the importance of immunogenetic factors (TNF-α polymorphism at -238 position), above other factors previously accepted (age, gender, alcohol, immunodepression), on the evolution to liver cirrhosis among HIV-infected patients with established chronic HCV infections.

Hepatoprotective effect of silyamarin in individuals chronically exposed to hydrogen sulfide; modulating influence of TNF-α cytokine genetic polymorphism

BACKGROUND AND THE PURPOSE OF THE STUDY

Silymarin, a standardized extract of the milk thistle (Silybum marianum), is believed to exert some of its hepatoprotective effects though inhibition of free radicals and inflammation. In this study the effect of some pro- and anti-inflammatory cytokines and also antioxidant genes polymorphisms on the hepatoprotective effects of silymarin in the occupationally exposed individuals to hydrogen sulfide (H2S) in the sour natural gas refinery was investigated.

METHODS

We genotyped seven polymorphisms in six genes reported by others as modifiers of oxidative stress (NQO1, mEPXH1, GSTT1 and GSTM1) and inflammation (TNF-α and TGF-β1) for an association in effect of decreasing in liver function tests (LFTs). The LFTs of 77 sour gas refinery workers were measured before and after administration of silymarin (140 mg, three times per day for 1 month).

RESULTS

A significant reduction of blood AST, ALT and ALP was observed after 30 days of consumption (p < 0.001). The decreasing effect of silymarin on ALT in the subjects with high producer genotype (A allele carriers) was less than low producers. There were no significant associations between TGF-β1 and the studied genes of oxidative stress pathway and the effectiveness of silymarin.

CONCLUSION

This is the first report about the effectiveness of silymarin in the subjects exposed chronically to H2S. Meanwhile, the modulatory effect of TNF-α on the effectiveness of silymarin might be used for individualize therapy.

Polymorphisms in interleukin-10 and interleukin-28B genes in Egyptian patients with chronic hepatitis C virus genotype 4 and their effect on the response to pegylated interferon/ribavirin-therapy

BACKGROUND AND AIM

Recently, it has been suggested that single nucleotide polymorphisms (SNPs) in some cytokine genes may influence the production of the associated cytokines that affect the host immune response to pegylated interferon-α (Peg-IFN-α) with ribavirin (RBV) in hepatitis C virus (HCV) patients. The aim of the present study was to investigate the possible role of the SNPs of IL-10 and Il-28B and their serum levels in predicting the response to treatment of HCV-4.

METHODS

Egyptian patients were treated with Peg-IFN-α/RBV. A total of 100 HCV genotype 4-infected patients and 80 healthy control subjects were included in the present study. SNPs in the IL-10 (-592 A/C and -819 T/C) and IL-28B (rs8099917 T/G and rs12979860 C/T) genes and their serum levels were assessed. The IL-10-592-CC, IL-28-rs8099917-TT and IL-28-rs12979860-CC genotypes were significantly higher in responders than in non-responders.

RESULTS

Interestingly, the serum levels of IL-10 were significantly increased; in contrast, the serum levels of Il-28B were significantly decreased in HCV patients compared with normal patients. Polymorphisms in IL-28B are more sensitive (P < 0.001) than those in IL-10-592 (P = 0.03). However, the serum level of IL-10 is higher than that of IL-28, and this difference can serve as a prognostic marker using a receiver operator characteristic (ROC) analysis.

CONCLUSIONS

It can be concluded that SNPs in IL-28B and the serum levels of Il-10 and IL-28 may be promising predictors for HCV therapy.

Pharmacogenetics of efficacy and safety of HCV treatment in HCV-HIV coinfected patients: significant associations with IL28B and SOCS3 gene variants

BACKGROUND AND AIMS

This was a safety and efficacy pharmacogenetic study of a previously performed randomized trial which compared the effectiveness of treatment of hepatitis C virus infection with pegylated interferon alpha (pegIFNα) 2a vs. 2b, both with ribavirin, for 48 weeks, in HCV-HIV coinfected patients.

METHODS

The study groups were made of 99 patients (efficacy pharmacogenetic substudy) and of 114 patients (safety pharmacogenetic substudy). Polymorphisms in the following candidate genes IL28B, IL6, IL10, TNFα, IFNγ, CCL5, MxA, OAS1, SOCS3, CTLA4 and ITPA were assessed. Genotyping was carried out using Sequenom iPLEX-Gold, a single-base extension polymerase chain reaction. Efficacy end-points assessed were: rapid, early and sustained virological response (RVR, EVR and SVR, respectively). Safety end-points assessed were: anemia, neutropenia, thrombocytopenia, flu-like syndrome, gastrointestinal disturbances and depression. Chi square test, Student's T test, Mann-Whitney U test and logistic regression were used for statistic analyses.

RESULTS

As efficacy is concerned, IL28B and CTLA4 gene polymorphisms were associated with RVR (p<0.05 for both comparisons). Nevertheless, only polymorphism in the IL28B gene was associated with SVR (p = 0.004). In the multivariate analysis, the only gene independently associated with SVR was IL28B (OR 2.61, 95%CI 1.2-5.6, p = 0.01). With respect to safety, there were no significant associations between flu-like syndrome or depression and the genetic variants studied. Gastrointestinal disturbances were associated with ITPA gene polymorphism (p = 0.04). Anemia was associated with OAS1 and CTLA4 gene polymorphisms (p = 0.049 and p = 0.045, respectively), neutropenia and thromobocytopenia were associated with SOCS3 gene polymorphism (p = 0.02 and p = 0.002, respectively). In the multivariate analysis, the associations of the SOCS3 gene polymorphism with neutropenia (OR 0.26, 95%CI 0.09-0.75, p = 0.01) and thrombocytopenia (OR 0.07, 95%CI 0.008-0.57, p = 0.01) remained significant.

CONCLUSIONS

In HCV-HIV coinfected patients treated with PegIFNα and ribavirin, SVR is associated with IL28B rs8099917 polymorphism. HCV treatment-induced neutropenia and thrombocytopenia are associated with SOCS3 rs4969170 polymorphism.

Is interleukin-10 gene polymorphism a predictive marker in HCV infection?

The clinical outcome of hepatitis C virus (HCV) infection varies between individuals - from spontaneous viral clearance and persistence without complication, to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Also patterns of response to interferon-based anti-HCV therapy are different from person to person. This diversity may be affected by host genetic factors, including alterations in genes encoding cytokines. Interleukin-10, as an anti-inflammatory cytokine and immune response modulator, may influence on HCV infection susceptibility as well as spontaneous and treatment-induced HCV eradication. Moreover, it is stated that IL-10 has antifibrotic properties and play a role in progression of liver disease. This review summarized studies on interleukin-10 gene polymorphisms (mainly promoter SNPs at positions -1082(G/A), -819(C/T) and -592(C/A)), which may determine IL-10 production, regarding susceptibility to HCV infection, course of HCV-related liver disease (fibrosis, cirrhosis, hepatocellular carcinoma, ALT abnormalities), spontaneous viral elimination as well as hepatitis C treatment outcomes. Analysis of hereby summarized studies shows that it is difficult to unambiguously determine the importance of IL-10 polymorphism as a predictor of clinical outcome of hepatitis C and response to anti-HCV therapy before its beginning. Thus, future larger studies need to address these issues. Continuation of studies on interleukin-10 polymorphisms as well as identification of other candidate predictive markers in HCV infection has important practical implications and there is a chance that may contribute to reduce the scale of hepatitis C problem.

Tumor necrosis factor-alpha -308G/A polymorphism and risk of hepatocellular carcinoma in hepatitis C virus-infected patients

Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms (SNPs) in its gene structure. We hypothesized that SNPs in TNF-α may be important in determining the outcome of an HCV infection. To test this hypothesis, we investigated the role of the polymorphism -308G/A, which is located in the promoter region of the TNF-α gene, in the progression of HCV infection in Egyptian patients using a quantitative real-time polymerase chain reaction (qRT-PCR). The distribution of this polymorphism and its impact on the serum level of TNF-α was compared between 90 HCV-infected patients [45 with HCV-induced cirrhosis and 45 with HCV-related hepatocellular carcinoma (HCC)] and 45 healthy Egyptian volunteers without any history of liver disease. Our results showed that at the TNF-α -308 position, the G/G allele was most common (78.5%) in the study population, with the G/A and A/A alleles occurring less frequently (13.3% and 8.1%, respectively). Frequencies of G/G, G/A, and A/A genotypes were 87%, 7%, and 6% in patients with liver cirrhosis and were 94%, 4%, and 2% in patients with HCC, respectively. Serum levels of TNF-α were significantly higher in HCV-infected patients than in healthy controls, indicating that the TNF-α -308 polymorphism does not influence the production of TNF-α. The serum level of TNF-α was positively correlated with HCV infection. Taken together, these findings suggest that the TNF-α -308 polymorphism may not be a host genetic factor associated with the severity of HCV infection, but may be an independent risk factor for HCC.

Polymorphism of tumor necrosis factor-α and interleukin-10 gene promoter region in chronic hepatitis C virus patients and their effect on pegylated interferon-α therapy response

The development and resolution of an inflammatory process is regulated by a complex interplay among cytokines that have pro- and anti-inflammatory effects. Regulatory mechanisms that control the production of cytokines include genetic polymorphism in particular promoter/leader region. Polymorphisms may directly or indirectly affect the binding of transcriptional factors, consequently increasing or decreasing the production of mRNA, thus regulating cytokine production. A total of 70 hepatitis C virus (HCV) RNA-positive patients and 70 healthy control subjects were included in the present study, who were attending the medical outpatient department (OPD) and wards of a tertiary care hospital in New Delhi during 2006-2008. This study was designed to determine the polymorphism of tumor necrosis factor-α and interleukin-10 genes in patients with chronic HCV infection patients and their effect on pegylated interferon-α therapy response. Polymorphism in the tumor necrosis factor-α G/G, G/A, and A/A genotype was significant between HCV patients and healthy controls. Interleukin-10 variants (G/G, G/A) were nonsignificant among HCV patients compared with healthy controls. As this is a preliminary study on small sample size, we believe that our findings may stimulate further studies on larger number of patients from this geographic region.

Cytokine and apoptosis gene polymorphisms influence the outcome of hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) infection is thought to be chronic and the factors leading to viral clearance or persistence are poorly understood. This study was undertaken to investigate the possibility of a significant relationship between the spontaneous clearance or the persistence of hepatitis C virus (HCV) infection and cytokine and apoptosis gene polymorphisms in Tunisian patients on hemodialysis.

METHODS

Polymorphisms of the genes IL-1 (-889 IL-1alpha, -511 and +3954 IL-1beta, IL-1Ra), IL-18 (-137 and -607), IL-12 (-1188) and Apo1/Fas (-670) were determined by PCR-RFLP, PCR-SSP and PCR-VNTR in 100 healthy blood donors and 100 patients infected with HCV and undergoing hemodialysis. The patients were classified into two groups: G1 consisted of 76 active chronic hepatitis patients (positive for HCV RNA) and G2 consisted of 24 hemodialysed patients who spontaneously eliminated the virus (negative for HCV RNA).

RESULTS

The frequency of genotype association [-137GC/-607CA] IL-18 was higher in G2 (41.7%) than in G1 (15.8%) (P=0.008; OR=0.26; 95% CI, 0.10-0.73). We also found a higher frequency of the AA genotype of the Apo1/Fas gene in G2 (41.6%) than in G1 (17.5%) (P=0.026; OR=3.49; 95% CI, 1.13-10.69). Adjustment for known covariate factors (age, gender and genotype) confirmed these univariate findings and revealed that the genotype association GC-CA of the (-137 and -607) IL-18 gene and the AA genotype of the Apo1/Fas gene were associated with the clearance of HCV (P=0.041 and 0.017, respectively).

CONCLUSION

The two genotypes GC-CA of the (-137 and -607) IL-18 polymorphism and the AA genotype of the Apo1/Fas gene influence the outcome of HCV infection in Tunisian patients on hemodialysis.

Genes and hepatitis C: susceptibility, fibrosis progression and response to treatment

Hepatitis C virus contact and infection show three different phenotypes: spontaneous viral clearance (SVC), chronic hepatitis C (CHC) and sustained virological response (SVR) following antiviral treatment. Many factors, including genetics, influence the evolution of these three phenotypes. We performed a literature search (PubMed) up to 31 January 2010 without language restriction to identify relevant studies on genes and hepatitis C. Additional studies were sought by reviewing the reference lists of the identified articles. Meta-analysis (using Meta-disk 1.4) was conducted to evaluate the association of single nucleotide polymorphism (SNP) in the IL28B region and SVR. The candidate gene approach showed strong relationships between human leucocyte antigen class II (DQB1(*) 0301 and DRB1(*) 1101) and SVC. A cirrhosis risk score involving 7 SNPs has been validated recently. The set of odds ratios of studies demonstrated an association between SNP (rs12987960/rs8099917) in the IL28B and SVR in CHC treated with peginterferon plus ribavirin (OR: 4.6; 95% CI: 2.9-7.3). The overall distribution of protective allele correlated with ethnic differences in SVR (Asians, Europeans, Hispanic and Afro-Americans) together with SVC, but not with fibrosis stage or viral load. These polymorphisms did not influence SVR in very-easy-to-treat patients such as genotype 2/3, rapid virological responders or patients with acute hepatitis C. While the genetic fingerprint for fibrosis progression remains elusive, IL28b polymorphism predicts SVC and SVR. However, nearly half of patients achieving SVR did not show favourable genotype. Further genetic signals are warranted to complete the puzzle of factors influencing hepatitis C.

Transforming growth factor β1 polymorphisms and progression of graft fibrosis after liver transplantation for hepatitis C virus--induced liver disease

Re-infection with the hepatitis C virus (HCV) is an important development after liver transplantation (LT); it can lead to graft fibrosis. The aim of this study was to assess the role of transforming growth factor β1 (TGF-β1) polymorphisms in the development of HCV-related graft disease by evaluating protocol liver biopsies. A total of 192 patients with a recurrence of HCV infection after LT were genotyped for TGF-β1 codon 10 (C→T) and codon 25 (G→C) using the polymerase chain reaction. Histological evaluation of 614 protocol liver biopsies obtained from these patients was undertaken using the classification of Desmet and Scheuer to stage the degree of fibrosis. Mild stages of fibrosis (0-2) were compared to advanced stages of fibrosis (3-4) that developed during the period of infection with the virus. Correlations between the prevalence of TGF-β1 genotypes and the different degrees of fibrosis that developed were determined. No statistically significant differences were found for genotype distributions (codons 10 and 25) with respect to recipient age, donor sex, occurrence of acute cellular rejection, and response to antiviral therapy. However, the C allele at codon 25 was significantly less frequent in the group with advanced fibrosis (P = 0.001). Furthermore, a positive association was found between progression of fibrosis and male recipient sex (P = 0.024), donor age (P = 0.041), and viral genotype 1b (P = 0.002). In conclusion, this study, in which the evolution of hepatic fibrosis was assessed histologically in a large cohort of patients with HCV re-infection after LT, has demonstrated that the C allele at codon 25 of the TGF-β1 gene is a marker for the development of graft fibrosis.

Combined effect of pro- and anti-inflammatory cytokine gene polymorphisms on susceptibility to liver cirrhosis in Tunisian HCV-infected patients

PURPOSE

Chronic hepatitis C progression is commonly attributed to the continuous activation of the immune response with an increased production of pro-inflammatory cytokines, leading to fibrosis and ultimately to cirrhosis. On the contrary, anti-inflammatory cytokines, mainly interleukin (IL)-10 have a modulatory effect on hepatic fibrogenesis. The association between individual polymorphisms within cytokine genes and hepatitis C outcome is often weak and non-informative. Interestingly, it has been demonstrated that a combination of specific genotypes may be a more significant and powerful approach for predicting disease risk.

AIM

This study is aimed at investigating the combined effect of single nucleotide polymorphism (SNP) in IL-18 (-607C/A, -137G/C), interferon (IFN)-γ (+874T/A) and IL-10 (-1082G/A) genes on cirrhosis risk in HCV-infected patients.

METHODS

Seventy-seven chronic hepatitis C Tunisian subjects were included in this study. The patients were divided into two groups: the first included 31 non-cirrhotic patients, and the second included 46 liver cirrhosis patients. IL-18 genotyping was performed using the PCR amplification and the restriction fragment length polymorphism analysis (RFLP). IFN-γ and IL-10 polymorphisms were analyzed using the allele-specific PCR (AS-PCR).

RESULTS

The combined high-risk genotype (IL-18 -607C/*, IL-18 -137G/*, IFN-γ +874T/*, IL-10 -1082A/A) frequency was compared between patients with and those without cirrhosis. Individuals were classified according the number of high-risk genotypes as follows: (0-2), patients with at most two high-risk genotypes; (3-4), patients with at least three of the high-risk genotypes. The logistic regression analysis showed that patients harboring 3-4 putative high-risk genotypes have a fivefold higher risk for developing cirrhosis in comparison to those harboring at most two high-risk genotypes (OR = 5.19; 95% CI = 1.49-18.05; p = 0.009).

CONCLUSION

Our study showed that the co-inheritance of IL-18, IFN-γ and IL-10 specific high-risk genotypes is associated with a greater risk for liver cirrhosis.

Immune and genetic mechanisms of infertility andreproductive function disorders associated with humanurogenital chlamydial infection

This review covers current concepts of immune and genetic mechanisms of infertility associated with human urogenital chlamydial infection. It describes studies of individual polymorphisms of genes coding cytokines and other immune system mediators. It also presents the results of studies aimed at searching for genetic predisposition to the development of complications resulting in human reproductive function disorders caused by past urogenital chlamydial infections.

Genetic polymorphisms, their allele combinations and IFN-beta treatment response in Irish multiple sclerosis patients

INTRODUCTION

IFN-beta is widely used as first-line immunomodulatory treatment for multiple sclerosis. Response to treatment is variable (30-50% of patients are nonresponders) and requires a long treatment duration for accurate assessment to be possible. Information about genetic variations that predict responsiveness would allow appropriate treatment selection early after diagnosis, improve patient care, with time saving consequences and more efficient use of resources.

MATERIALS & METHODS

We analyzed 61 SNPs in 34 candidate genes as possible determinants of IFN-beta response in Irish multiple sclerosis patients. Particular emphasis was placed on the exploration of combinations of allelic variants associated with response to therapy by means of a Markov chain Monte Carlo-based approach (APSampler).

RESULTS

The most significant allelic combinations, which differed in frequency between responders and nonresponders, included JAK2-IL10RB-GBP1-PIAS1 (permutation p-value was p(perm) = 0.0008), followed by JAK2-IL10-CASP3 (p(perm) = 0.001).

DISCUSSION

The genetic mechanism of response to IFN-beta is complex and as yet poorly understood. Data mining algorithms may help in uncovering hidden allele combinations involved in drug response versus nonresponse.

Interleukin-10 promoter polymorphisms in hepatitis C patients with and without Schistosoma mansoni co-infection

BACKGROUND/AIM

Interleukin (IL-10) plays a major role in chronic hepatitis C virus (HCV) disease pathogenesis, in particular in Schistosoma mansoni (S. mansoni) co-infected patients. Given that interindividual variations in IL-10 production are influenced by functional polymorphisms in the IL-10 gene promoter, we determined the frequencies of common (-1082, -819 and -592) IL-10 promoter polymorphisms in chronic HCV patients with and without S. mansoni co-infection and healthy controls, and investigated their association with the degree of histological activity index (HAI) and response to interferon-ribavirin therapy.

METHODS

Genomic DNA from 99 patients and 62 healthy controls, born in the same geographical hyperendemic area, was studied by the polymerase chain reaction, followed by restriction enzyme digestion. Sera were assessed for S. mansoni antibodies.

RESULTS

The frequencies of IL-10 polymorphisms at positions -1082, -819 and -592 from the transcription start site were comparable between HCV patients and controls, as well as between HCV mono-infected and either S. mansoni co-infected patients or controls. The grade of inflammation and the stage of fibrosis showed no association with IL-10 polymorphisms. The frequencies of S. mansoni co-infection and IL-10 genotypes/haplotypes were insignificantly different between non-responders and responders to combination therapy. No effect of other factors like age, gender, HAI group scores and serum alanine aminotransferase and aspartate aminotransferase levels was observed on response to therapy in our patients.

CONCLUSION

Our findings suggest that common IL-10 (-1082, -819 and -592) genotypes/haplotypes do not influence the degree of HAI and response to combination therapy or susceptibility to HCV infection with and without S. mansoni co-infection.

Combined analysis of interferon-gamma and interleukin-10 gene polymorphisms and chronic hepatitis C severity

Today there is increasing evidence concerning the contribution of pro-/anti-inflammatory cytokine balance and genetic factors in hepatitis C pathogenesis and interindividual heterogeneity of disease outcome. In the current study, we investigated the influence of functionally described single nucleotide polymorphisms (SNPs) present in interferon-gamma (IFNgamma) and interleukin-10 (IL-10) genes, on chronic hepatitis C severity. IFNgamma (+874T/A) and IL-10 (-1082G/A) genotypes were determined in 100 hepatitis C patients with different disease severities (chronic hepatitis, n = 42, liver cirrhosis [LC], and hepatocellular carcinoma in liver cirrhosis [HCC], n = 58) and 103 healthy controls using allele-specific polymerase chain reaction. No statistical differences in allele or genotype distributions of IFNgamma and IL-10 genes were observed between patients and controls. However, some significant differences in IFNgamma genotype frequencies were observed between the two groups of patients. IFNgamma(high producer) genotypes TT and TA were significantly more common in patients with LC and HCC (odds ratio = 2.65; p = 0.019). Although IL-10 genotypic frequencies were comparable between the different clinical forms of the disease, the combination of IFNgamma(low producer) and IL-10(high producer) genotypes was significantly associated with a lower risk of LC and HCC (odds ratio = 0.21; p = 0.015). In conclusion, our findings suggest that the imbalance between the pro-inflammatory and anti-inflammatory responses mediated by polymorphisms in the IFNgamma and IL-10 genes may influence the outcome of chronic HCV infection.

Recognition of genetic factors influencing the progression of hepatitis C : potential for personalized therapy

Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. Hepatic fibrosis may develop in subjects with chronic HCV infection, culminating in cirrhosis and an increased risk of hepatocellular carcinoma. The rate of development of fibrosis varies substantially between individuals; while it is influenced by a number of demographic and environmental factors, these account for only a small proportion of the variability. There are no clinical markers or tests that predict the rate of fibrosis progression in an individual subject. Thus, there has been increasing interest in the influence of host genetic factors on the rate of disease progression, and whether a genetic signature can be developed to reliably identify individuals at risk of severe disease. Numerous case-control, candidate gene, allele-association studies have examined the relationship between host single nucleotide polymorphisms or other genetic mutations and fibrosis in patients with chronic HCV infection. However, these studies have generally been irreproducible and disappointing. As seen with genetic studies for other diseases, small study cohorts and poor study design have contributed to limited meaningful findings. The successful determination of genetic signatures for fibrosis progression in chronic HCV will require multicenter collaborations using genome-wide association studies, with large, phenotypically well-defined sample sets. While these studies will require a significant financial commitment, a successful outcome offers the potential for personalized therapy and better patient management.