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

Hepatitis C in North Africa: A Comprehensive Review of Epidemiology, Genotypic Diversity, and Hepatocellular Carcinoma

Hepatitis C virus (HCV) is implicated in carcinogenic infections like hepatocellular carcinoma (HCC). Given that no HCV vaccine is currently available, comprehensive epidemiological understanding is crucial for devising effective prevention strategies. In North Africa, existing data on HCV infection and HCV-associated HCC are frequently outdated or limited to specific populations. This systematic review aims to offer new insights into the epidemiology of HCV infection, HCV genotype distribution, and HCV-related HCC in this region. We collected data from electronic databases: PubMed, ScienceDirect, ResearchGate, Google Scholar, and public health reports between 1989 and 2023. We reported the studies carried out in each country in general populations and in groups exposed to HCV infection. Our results show that HCV prevalence varies from 0.5% to 4.61% among the general populations in North African countries. HCV genotype 1 remains the most dominant in the Greater Maghreb region, while genotype 4 is the most dominant in the Nile Valley region. HCC incidence varies between the five countries, and HCV is responsible for 60% of cases, with male dominance. Egypt had the highest number of deaths from HCV-associated HCC. Other factors such as HBV, diabetes, and alcohol use are also responsible for HCC in North Africa. Urban growth and socioeconomic changes have impacted HCV prevalence in the North African region, especially among rural populations, and introduced new risks, such as coinfections and Type 2 diabetes. Here, we propose some recommendations for HCV control and management by patient category in North Africa.

Association of an IFN-γ variant with susceptibility to chronic hepatitis B by the enhancement of HBV DNA replication

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874T^high → A^low)] may alter the outcomes of chronic HBV infection in Tunisian population. The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls. We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10^-4; 24 vs. 13%, P < 10^-4; 52 vs. 38%, P < 10^-4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively]. The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively]. Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.

Hepatitis C in Tunisia from 1991 to 2019: A systematic review

BACKGROUND

Hepatitis C virus (HCV) is one of the leading causes of chronic liver disease and liver cancer related deaths in Tunisia.

AIM

Perform a systematic review on viral hepatitis C in Tunisia between 1991 and 2019.

METHODS

A global search of HCV-specific documentation in Tunisia (1991-2019) in bibliographic data search sites.

RESULTS

Tunisia is a low endemic country for hepatitis C with a prevalence that not exceed 1% in the general population. Several studies have focused on populations at risk of HCV contamination such as hemodialysis and polytransfused patients. The prevalence of hepatitis C is higher in these groups. In relatively small series, a clear predominance of genotype 1 and subtype 1b has been reported in Tunisia with a lower co-circulation of the other genotypes. Several polymorphisms of cytokine and chemokine genes can influence the clearance or persistence of HCV infection. Tunisian studies have focused on the efficacy of conventional dual therapy (pegylated IFN + ribavirin) by analyzing the predictive factors linked to SVR and mutations associated with resistance to viral inhibitors. No publication has discussed the effectiveness of new direct-acting antivirals in Tunisia.

CONCLUSION

This review of the literature provides an update on the status of hepatitis C in Tunisia and reveals a lack of investigations on new direct-acting antivirals.

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.

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.

IL-10 and IL-28B gene variants as predictors of sustained response to peginterferon and ribavirin therapy in chronic HCV infection

OBJECTIVES

Interleukin-10 (IL-10) plays an important role in the immunity to hepatitis C virus (HCV). Insofar as IL-10 variants are associated with altered levels of IL-10, previous studies that examined the association of IL-10 polymorphisms with the susceptibility to and progression of chronic HCV, and response to anti-viral treatment were inconsistent. We investigated the association between common IL-10 variants in the intron and the promotor region with HCV and associated features.

METHODS

Study subjects comprised 120 patients infected with HCV-1b, and treated with Peg-IFN/RBV. Genotyping of six IL-10 promoter variants in the intron region (rs1878672, rs1554286, rs1518111) and promotor region (rs1800872, rs1800871, rs1800896) were done by real-time PCR.

RESULTS

Compared to G/G, carriage of IL-10 rs1800896 (-1082A/G) A/A genotype was more frequent in patients with sustained virological response (SVR). The decline in viral load over the first 12weeks of treatment was more pronounced in rs1800896 A/A genotype carriers, compared to G/G genotype carriers, and was irrespective of the treatment dosage. Carriage of rs1800896 A/A genotype was positively associated with improvement in viral load decline, which was simultaneous, with and without carriage of the common favourable IL-28B variant. Carriage of both IL-10 rs1800896 G/G and IL-28B non-favourable genotype was associated with twice the risk of getting slow decline of viral load during treatment. Haploview analysis identified ACGCTA and CCGCTG haplotypes to be linked with excellent PegIFN/RBV cure rate, and complete HCV eradication. On the other hand, ACGCTG and CCGCTA haplotypes were associated with resistance to PegIFN/RBV treatment.

CONCLUSION

IL-10 rs1800896 variant markedly influences the clinical outcome of HCV infection, and is a determinant of the response to HCV treatment.

Genetic polymorphisms -137 (rs187238) and -607 (rs1946518) in the interleukin-18 promoter may not be associated with development of hepatocellular carcinoma

This study meta-analyzed the literature on possible association of polymorphisms -137 (rs187238) and -607 (rs1946518) in the interleukin-18 (IL-18) promoter with risk of hepatocellular carcinoma (HCC). The analysis included 8 case-control studies on the -137 polymorphism (1,318 cases, 2,254 controls) and 7 case-control studies on the -607 polymorphism (1,262 cases, 1,696 controls). None of the five genetic models suggested a significant association between the -137 polymorphism and HCC risk: allelic model, OR 0.99, 95% CI 0.74-1.34, P = 0.97; recessive model, OR 0.98, 95% CI 0.65-1.46, P = 0.91; dominant model, OR 1.35, 95% CI 0.73-2.52, P = 0.34; homozygous model, OR 0.99, 95% CI 0.65-1.49, P = 0.95; heterozygous model, OR 0.99, 95% CI 0.66-1.48, P = 0.94. Similar results were obtained in subgroup analyses of Asian patients, Chinese patients, or patients with hepatitis B virus (HBV)-related HCC. Similar results were also obtained for the -607 polymorphism across the entire study population as well as in the three subgroups. The available evidence suggests no significant association of the -137 or -607 polymorphisms with risk of HCC in general or specifically of HBV-related HCC. These conclusions should be verified in large, well-designed studies.

Interferon gamma polymorphisms and hepatitis B virus-related liver cirrhosis risk in a Chinese population

Background

Previous studies proved that interferon gamma (IFN-γ) gene polymorphisms were associated with the risk of hepatitis B virus (HBV) infection. However, the association between IFN-γ polymorphisms and HBV-related liver cirrhosis (HBV-LC) risk is still unclear.

Methods

IFN-γ +874 T/A and +2109G/A genotypes were determined in 126 HBV-LC patients, 129 chronic hepatitis B(CHB) patients, and 173 early HBV infection controls using a sequence-specific primer-polymerase chain reaction and a polymerase chain reaction-restriction fragment length polymorphism, respectively.

Results

Significant associations were observed between +2109A/G polymorphisms and HBV-LC risk in the co-dominant model (GG vs. AA: OR = 0.321, 95% CI = 0.130-0.793, P = 0.014), the allelic model (OR = 0.565, 95% CI = 0.388-0.825, P = 0.003), the dominant model (OR = 0.551, 95% CI = 0.344-0.883, P = 0.013), and the recessive model (OR = 0.385, 95% CI = 0.159-0.930, P = 0.034). In addition, haplotype analysis indicated that the T⁺⁸⁷⁴G⁺²¹⁰⁹ haplotype significantly decreased the HBV-LC risk (OR = 0.106, 95% CI = 0.022-0.502, P = 0.000), and A⁺⁸⁷⁴A⁺²¹⁰⁹ haplotype significantly increased the LC risk (OR = 1.485, 95% CI = 1.065-2.070, P = 0.019). No significant associations were observed between IFN-γ +874 T/A polymorphisms and HBV-LC risk, as well as the two single-nucleotide polymorphisms (SNPs) and CHB risk (P > 0.05).

Conclusions

Our observations suggested a significant association of IFN-γ polymorphisms with HBV-LC risk in the Chinese population.

The epidemiology of hepatitis C virus in the Maghreb region: systematic review and meta-analyses

Objective

To systematically review and synthesize available epidemiological data on hepatitis C virus (HCV) prevalence and incidence in the Maghreb region and to estimate the country-specific population-level HCV prevalence.

Methods

We conducted a systematic review of HCV antibody prevalence and incidence in the Maghreb countries as outlined by the PRISMA guidelines. Meta-analyses were conducted using DerSimonian-Laird random-effect models with inverse variance weighting to pool HCV prevalence estimates among general population groups.

Results

We identified 133 HCV prevalence measures and two HCV incidence measures. Among high risk groups, HCV prevalence ranged between 22% and 94% among people who inject drugs, 20% and 76% among dialysis patients, and 2% and 51% among hemophiliacs. Among intermediate-risk groups, considerable but widely variable HCV prevalence was found. Most common risk factors cited across studies were the duration of dialysis, number of transfusions, and having a history of surgery or dental work. The national HCV prevalence in Algeria was estimated at 0.3% (95%CI: 0.1–0.5), Libya 1.2% (95%CI: 1.1–1.3), Mauritania 1.1% (95%CI: 0–2.3), Morocco 0.8% (95%CI: 0.5–1.2), and Tunisia 0.6% (95%CI: 0.5–0.8).

Conclusions

HCV prevalence in the Maghreb region of the Middle East and North Africa is comparable to that in developed countries of about 1%. HCV exposures appear often to be linked to medical care and are suggestive of ongoing transmission in such settings. Injecting drug use appears also to be a major, though not dominant, contributor to HCV transmission. Further research is needed to draw a more thorough understanding of HCV epidemiology, especially in the countries with limited number of studies. HCV prevention policy and programming in these countries should focus on the settings of exposure.

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.

Smad3 phospho-isoform signaling in hepatitis C virus-related chronic liver diseases

The risk of hepatocellular carcinoma (HCC) development increases as hepatitis virus C (HCV)-related liver diseases progress, especially in patients with active inflammation. Insight into hepatic carcinogenesis have emerged from recent detailed analyses of transforming growth factor-β and c-Jun-N-terminal kinase signaling processes directed by multiple phosphorylated (phospho)-isoforms of a Smad3 mediator. In the course of HCV-related chronic liver diseases, chronic inflammation and host genetic/epigenetic alterations additively shift the hepatocytic Smad3 phospho-isoform signaling from tumor suppression to carcinogenesis, increasing the risk of HCC. Chronic inflammation represents an early carcinogenic step that provides a nonmutagenic tumor-promoting stimulus. After undergoing successful antiviral therapy, patients with chronic hepatitis C could experience a lower risk of HCC as Smad3 phospho-isoform signaling reverses from potential carcinogenesis to tumor suppression. Even after HCV clearance, however, patients with cirrhosis could still develop HCC because of sustained, intense carcinogenic Smad3 phospho-isoform signaling that is possibly caused by genetic or epigenetic alterations. Smad3 phospho-isoforms should assist with evaluating the effectiveness of interventions aimed at reducing human HCC.

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.