Hepatitis C Virus Genetic Variability, Human Immune Response, and Genome Polymorphisms: Which Is the Interplay?

Norovirus evolves as one or more distinct clonal populations in immunocompromised hosts

Noroviruses are a major cause of acute gastroenteritis worldwide and can establish chronic infection in immunocompromised individuals. To investigate the mechanisms of norovirus evolution during chronic infection, we selected seven representative patients from a National Institutes of Health study cohort who sustained norovirus infection for periods ranging from 73 to 1,492 days. Six patients shed viruses belonging to a single genotype (GII.2[PNA], GII.4 New Orleans[P4], GII.4 Den Haag[P4], GII.3[P21], GII.6[P7], or GII.14[P7]) over the period examined, while one patient sequentially shed two genotypes (GII.6[P7] followed by GII.4 Sydney[P31]). Norovirus genomes from consecutive stool samples were sequenced at high resolution (>3,300 reads/nucleotide position) using the Illumina platform and subjected to bioinformatics analysis. Norovirus sequences could be resolved into one or more discrete clonal RNA genomes that persisted within these patients over time. Phylogenetic analyses inferred that clonal populations originated from a single founder virus and not by reinfection with community strains. Estimated evolutionary rates of clonal populations during persistent infection were similar to those of noroviruses from acute infection in the global database, suggesting that inherently higher RNA-dependent polymerase error rates were not associated with the ability to persist. The high-resolution analysis of norovirus diversity and evolution at the population level described here should allow a better understanding of adaptive mutations sustained during chronic infection. IMPORTANCE Noroviruses are an important cause of chronic diarrhea in patients with compromised immune systems. Presently, there are no effective therapies to clear the virus, which can persist for years in the intestinal tract. The goal of our study was to develop a better understanding of the norovirus strains that are associated with these long-term infections. With the remarkable diversity of norovirus strains detected in the immunocompromised patient cohort we studied, it appears that most, if not all, noroviruses circulating in nature may have the capacity to establish a chronic infection when a person is unable to mount an effective immune response. Our work is the most comprehensive genetic data set generated to date in which near full-length genomes from noroviruses associated with chronic infection were analyzed by high-resolution next-generation sequencing. Analysis of this data set led to our discovery that certain patients in our cohort were shedding noroviruses that could be subdivided into distinct haplotypes or populations of viruses that were co-evolving independently. The ability to track haplotypes of noroviruses during chronic infection will allow us to fine-tune our understanding of how the virus adapts and maintains itself in the human host, and how selective pressures such as antiviral drugs can affect these distinct populations.

Molecular Epidemiology of HCV RNA Genotype-3 in Dhaka City, Bangladesh

Hepatitis C virus (HCV) is a causative agent that causes chronic liver diseases worldwide. It is a little, enclosed, single-stranded ribonucleic acid (RNA) virus. The recognition of the pathogenic HCV genotype is critical for the remedy of its sufferers. The aim of this study was to identify the HCV RNA genotype to decide the correct treatment of hepatitis C positive sufferers in Bangladesh. Blood samples were collected from 390 individuals and isolated RNA (60 µg) from blood plasma. Extracted RNA was used for quantitative HCV RNA, and complementary DNA (cDNA) was prepared by polymerase chain reaction (PCR) conducted by reverse transcriptase enzyme. This cDNA amplified in multiplex by RT-PCR, which was performed with specific set of primers. The HCV RNA genotype was detected 297 of 390 patients. Of the 390 test samples, 200 (51.28%) samples were from males and 190 (48.71%) were from females, with age ranging from 5 to 78 years. In all, 166 of 200 male samples and 131/190 female samples were found positive for HCV. Of these 390 participants included in the study, 213 (54.61%) were identified as genotype 3 positive, 78 (20%) as genotype 1 positive, 6 (1.53%) as genotype 6 positive, and the remaining 93 (23.85%) samples were unclassified due to low/undetected viral load. In this study, we detected the highest percentage (30.89%) of genotype 3 HCV in patients aged 51 to 60 years. The results suggested that genotype 3 HCV is frequently present in Bangladesh and it is usually responses better to interferon therapy. However, genotype 1 and 6 HCV have also been found circulating in this country, which demands longer treatments and effective control measures.

Association of NK Cells with the Severity of Fibrosis in Patients with Chronic Hepatitis C

Some NK cell subpopulations may be involved in the modulation of fibrogenesis in the liver. The aim of the study was to evaluate the relationship between the number and phenotype of NK cell subsets in peripheral blood (PB) and total NK cell percentage, population density and the degree of liver fibrosis of patients infected with hepatitis C virus (HCV+). The study group consisted of 56 HCV+ patients, divided into two subgroups: patients with mild or moderate fibrosis and patients with advanced liver fibrosis or cirrhosis (F ≥ 3 in METAVIR classification). The preparations were stained with H-E and AZAN staining. NK cells were targeted with anti-CD56 antibody and identified automatically in situ using the DakoVision system. Assessment of different NK cell subsets in PB was performed with the flow cytometry technique. In the PB of HCV+ patients with advanced liver fibrosis, there was a lower proportion of CD62L+; CD62L+/CD94++; CD27+; CD127+/CD27+ and CXCR3+/CD27+ NK subsets, as compared to patients with mild/moderate liver fibrosis. The results also showed no association between total PB NK cell level and total intrahepatic NK cell population density between patients with mild/moderate fibrosis and with advanced liver fibrosis. However, positive correlations between the PB levels of CD94+ and CD62L+ NK cell subsets and the intrahepatic total NK cell percentage and population density in the liver, irrespectively to the extent of fibrosis, were observed. Additionally, positive correlation was found between the PB CXCR3+/CD94+ NK cell percentages and intrahepatic NK cell percentages in patients with advanced hepatic fibrosis. Lower blood availability of specific NK subsets in patients with chronic type C hepatitis might be a cause of progression of liver fibrosis via insufficient control over hepatic stellate cells.

Interleukin 28B Polymorphism as a Predictor of Sustained Virological Response to Sofosbuvir-Based Therapy for Hepatitis C Virus Patients

In various genome-wide correlation studies, interleukin (IL)28B gene polymorphism has been strongly correlated with both the therapeutic and spontaneous mediated clearance of hepatitis C virus (HCV). Therefore, this study aimed to evaluate the genotype and allele frequency distributions of IL28B (rs12979860) in patients with chronic hepatitis C and assess the IL28B polymorphisms as predictors of sustained virological response to SOF-based therapy for HCV in Egyptian patients. This retrospective case-control study was conducted on 54 chronic HCV patients who completed treatment with SOF/DCV ± RBV for 12 weeks and responded to treatment with SVR12 (the responder group) as a control group, and 54 chronic HCV patients who completed treatment with SOF/DCV ± RBV for 12 weeks and did not respond to treatment and failed to achieve SVR12 (the non-responder group) as a case group. The CC genotype frequency of IL-28B (rs12979860) was greater in the responder group (51.9%). In contrast, the TT genotype frequency was higher in the non-responder group (48.1%) (p < 0.001), and the T allele significantly increased the risk of non-responses by 3.13 fold. Therefore IL-28B (rs12979860) SNP could be used as a genetic predictor of sustained virological response to SOF+DCV ± RBV-based HCV treatment in Egyptian patients.

ASSESSING PREDICTORS OF DIRECTLY ACTING ANTIVIRALS' FAILURE AS A FURTHER STEP TOWARDS MORE EFFICIENT HCV ELIMINATION PROGRAMS: IL28B (IFNL4) GENE POLYMORPHISM HAS NO ROLE WHILE HIGHER ESTIMATED CREATININE CLEARANCE IS A FORGOTTEN FACTOR

BACKGROUND

Sustained virologic response (SVR) rates after directly acting antivirals (DAAs) for hepatitis C virus (HCV) exceed 95%. This encouraged policymakers to put plans to achieve HCV elimination by 2030. The remaining percentage of non-SVR12 can affect HCV eradication strategies in the real-world especially the compliance of large numbers of treated persons to follow up for assessment of virologic response cannot be guaranteed.

OBJECTIVE

We aimed to assess predictors of failure to achieve SVR after receiving sofosbuvir plus NS5A inhibitor as an important step towards achieving better HCV eradication strategies.

METHODS

During the period from 1st November 2018 to 1st November 2019, 1581 treatment-naive patients received sofosbuvir plus daclatasvir ± ribavirin at our unit and 10 patients were referred to us with HCV relapse after the same regimens. A total of 163 out of the 1581 patients were lost for follow-up before assessment of virologic response and excluded from the analysis. 20 out of the remaining patients failed to achieve SVR12. Data from the 30 patients with non-SVR12 were included in the case-control analysis.

RESULTS

Every unit increase in estimated creatinine clearance using modification of diet in renal disease study (MDRD) score, total bilirubin, and INR was associated with 1.03, 13.92, and 80.08 times greater odds of non-SVR12 (P<0.001, P=0.0016, P=0.02) respectively. The presence of liver cirrhosis on ultrasonography increases the odds by 10.03. (P=0.009).

CONCLUSION

Higher MDRD score, INR, total bilirubin, and presence of sonographic features of liver cirrhosis are predictors of failure to achieve SVR12 using sofosbuvir plus NS5A inhibitor.

Induction of broadly neutralizing antibodies using a secreted form of the hepatitis C virus E1E2 heterodimer as a vaccine candidate

SignificanceHepatitis C virus chronically infects approximately 1% of the world's population, making an effective vaccine for hepatitis C virus a major unmet public health need. The membrane-associated E1E2 envelope glycoprotein has been used in clinical studies as a vaccine candidate. However, limited neutralization breadth and difficulty in producing large amounts of homogeneous membrane-associated E1E2 have hampered efforts to develop an E1E2-based vaccine. Our previous work described the design and biochemical validation of a native-like soluble secreted form of E1E2 (sE1E2). Here, we describe the immunogenic characterization of the sE1E2 complex. sE1E2 elicited broadly neutralizing antibodies in immunized mice, with increased neutralization breadth relative to the membrane-associated E1E2, thereby validating this platform as a promising model system for vaccine development.

Prospective cohort study of children exposed to hepatitis C virus through a pregnancy screening program

Objectives:

Porto Alegre, in south Brazil, has one of the highest Hepatitis C virus (HCV) infections rate in the country (84.4 cases/100,000 in 2018). Prenatal screening of HCV, however, has not been routinely offered.

Methods:

We conducted a longitudinal study of pregnant women with HCV and their infants between January 2014 to December 2018. Screening for HCV antibodies was offered to all women delivering at our tertiary institution. HCV RT-PCR was performed if seropositive. Infants were followed prospectively.

Results:

Among 18,953 pregnant women delivering, 17,810 were screened for HCV antibodies (93.9%) with 130 positive results. (HCV seroprevalence 0.7%). HCV RNA was detectable in 57/117 cases (48.7%). HCV viremia was associated with use of injectable drugs (p=0.03), inhaled/crack drug use (p=0.02), an HCV-seropositive partner, ≥3 lifetime sexual partners (p=<0.01). Genotype 1 was most prevalent (68%) during pregnancy. Among 43 children with follow-up, 6 (13%) were HCV infected (transmission rate 13.9%); genotype 3 infected 50%. Two infants (33%) cleared infection; mothers had genetic polymorphisms associated with clearance.

Conclusion:

HCV vertical transmission was high in our population, with HCV infection during pregnancy being vastly underdiagnosed. Public health efforts must focus on this vulnerable population for disease prevention and early treatment.

Polymorphism rs368234815 of interferon lambda 4 gene and spontaneous clearance of hepatitis C virus in haemodialysis patients: a case-control study

BACKGROUND

In non-uremic subjects, IFNL4 rs368234815 predicts HCV clearance. We investigated whether rs368234815 is associated with spontaneous HCV clearance in haemodialysis patients and whether it is a stronger predictor of HCV resolution than the IFNL polymorphisms already associated with HCV clearance in dialysis subjects. We also evaluated an association of rs368234815 with patients` survival and alterations in transcription factor binding sites (TFBS) caused by IFNL polymorphisms.

METHODS

Among 161 haemodialysis patients with positive anti-HCV antibodies, 68 (42.2%) spontaneously resolved HCV infection, whereas 93 remained HCV RNA positive. Patients were tested for near IFNL3 rs12980275, IFNL3 rs4803217, IFNL4 rs12979860, IFNL4 rs368234815, and near IFNL4 rs8099917. IFNL4 rs368234815 polymorphism (TT/TT, ΔG/TT, ΔG/ΔG) was genotyped by restriction fragment length polymorphism analysis; other IFNL polymorphisms - by high resolution melting curve analysis. We used the Kaplan-Meier method with the log-rank test for survival analysis. In silico analysis included the use of ENCODE TFBS ChIP-seq data, HOCOMOCO, JASPAR CORE, and CIS-BP databases, and FIMO software.

RESULTS

The probability (OR, 95%CI, P) of spontaneous HCV clearance for rs368234815 TT/TT patients was higher than for the ΔG allele carriers (2.63, 1.38-5.04, 0.003). This probability for other major homozygotes varied between 2.80, 1.45-5.43, 0.002 for rs12980275 and 2.44, 1.27-4.69, 0.007 for rs12979860. In the additive model, rs368234815 TT/TT was the strongest predictor of HCV clearance (6.38, 1.69-24.2, 0.003). Survival analysis suggested an association of the ΔG allele with mortality due to neoplasms (log-rank P = 0.005). The rs368234815 ∆G allele caused TFBS removal for PLAGL1.

CONCLUSIONS

In haemodialysis patients, the association of rs368234815 with the spontaneous HCV clearance is better than that documented for other IFNL3/IFNL4 polymorphisms only in the additive mode of inheritance. However, identifying the homozygosity in the variant ∆G allele of rs368234815 means a more potent prediction of persistent HCV infection in haemodialysis subjects that we observe in the case of the variant homozygosity of other tested IFNL3/IFNL4 polymorphisms. Removal of PLAGL1 TFBS in subjects harbouring the rs368234815 ∆G allele may contribute to cancer susceptibility. The association of rs368234815 with cancer-related mortality needs further studies in HCV-exposed subjects.

Design of a native-like secreted form of the hepatitis C virus E1E2 heterodimer

Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, along with a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to its expected size than full-length E1E2. Preservation of native structural elements was confirmed by high-affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2 and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.

Implications of viral transmitted/founder (T/F) dynamics on vaccine development

Viral infection typically originates from a limited number of virions known as transmitted/founder (T/F) viruses. Studies of cross-species transmission, and intra-species transmission of antigenically variable viruses, indicates T/F variants may express distinct, transmissibility enhancing phenotypes. However, with evidence that transmissibility is associated with not only intrinsic virological features, such as virion composition, but also extrinsic factors, such as viral population structure, the challenge of resolving T/F signatures that can be targeted by rational vaccine or antiviral design is substantial. Nonetheless, failure to develop vaccines for antigenically variable viruses, such as HIV/HCV, and the ongoing risk of cross-species transmission with pandemic potential, recommends development of T/F targeting vaccines. In this commentary, the T/F phenomena is introduced, explored in both the classical (HIV) and non-canonical (coronaviruses) instances, and discussed in relation to rational and preemptive vaccine design.

Body mass index (BMI) and alpha-fetoprotein (AFP) level correlate with the severity of HCV-induced fibrosis in a cohort of Egyptian patients with chronic HCV

Background

Viral hepatitis is the seventh leading cause of mortality globally, and half of this mortality is attributed to hepatitis C virus (HCV). Egypt has the highest HCV prevalence worldwide, with an estimated 14.7% of the population being HCV-positive. HCV infection is the primary cause of liver fibrosis, cirrhosis, and hepatocellular carcinoma. Liver fibrosis varies in severity during chronic HCV infection, and 10–20% of chronic hepatitis C (CHC) patients with severe fibrosis develop cirrhosis. The goal of this work was to assess the clinico-demographic predictors of severity of HCV-induced fibrosis in a cohort of Egyptian patients.

Results

A cohort of Egyptian patients with chronic HCV genotype 4a infection showed significant association between severe fibrosis stages and obesity, represented by a higher body mass index (BMI), low albumin level, high alpha-fetoprotein (AFP) level, low thyroid-stimulating hormone (TSH) level, and high alkaline phosphatase (ALP) level. Multivariate analysis delineated BMI, TSH, and ALP as independent significant variables that could predict the risk of fibrosis severity in HCV infections.

Conclusion

This study argues in favor of using the biomarker profile of CHC patients infected with HCV genotype 4a to identify patients at higher risk of developing severe fibrosis, which is a necessary first step towards precision medicine via patient stratification.

Low Mannose Binding Lectin, but Not L-Ficolin, Is Associated With Spontaneous Clearance of Hepatitis C Virus After Infection

Some individuals can spontaneously clear the hepatitis C virus (HCV) after infection, whereas others develop a chronic infection. The exact mechanism of this phenomenon is unknown. We aimed to evaluate the association of plasma levels of MBL, L-ficolin, and cytokines with outcome of HCV infections in two groups of patients who cleared HCV spontaneously (CHS), and who developed chronic HCV infections (CHC). Altogether, 86 patients and 183 healthy controls were included. Of 86 patients, 36 had CHS and 50 had CHC. Concentrations of plasma MBL and L-ficolin were measured in patients and controls. Twenty plasma cytokines and adhesion molecules, including GM-CSF, ICAM-1, IFN-γ, IFN-α, IL-1α, IL-1β, IL-10, IL-12p70, IL-13, IL-17A, IL-4, IL-8, IP-10, MCP-1, IL-6, MIP-1α, MIP-1β, sE-Selectin, sP-Selectin, and TNF-α, were determined in all patients and randomly selected 45 controls. The level of MBL was significantly lower in subjects with CHS than in healthy controls (median: 293.10 vs. 482.64 ng/ml, p = 0.008), whereas the level of MBL was significantly higher in patients with CHC than in controls (median: 681.32 vs. 482.64 ng/ml, p = 0.001). No such differences in plasma L-ficolin were observed. Plasma levels of all cytokines and adhesion molecules, except ICAM-1, were significantly higher in patients than in controls. Moreover, patients with CHC had significantly higher levels of IFN-γ, IFN-α, IL-1α, IL-10, IL-13, IL-4, IL-6, and TNF-α than those with CHS. These findings implicate that lower levels of plasma MBL, together with lower levels of above mentioned cytokines may play a part in virus clearance of HCV infection.

Risk Factors Contributing to the Occurrence and Recurrence of Hepatocellular Carcinoma in Hepatitis C Virus Patients Treated with Direct-Acting Antivirals

Although hepatitis C virus (HCV) RNA may be eliminated from blood circulation by direct-acting antivirals (DAA) therapy as assessed by real-time polymerase chain reaction (PCR), HCV RNA can still be present in liver tissue, and this is known as occult HCV. There has been a lot of controversy surrounding the recurrence of hepatocellular carcinoma (HCC) after DAA treatment of hepatic cells infected with chronic HCV. One of the main risk factors that leads to de novo HCC is the chronicity of HCV in hepatic cells. There are many studies regarding the progression of HCV-infected hepatic cells to HCC. However, there is a lack of research on the different molecular mechanisms that lead to the progression of chronic HCV infection to HCC, as well as on the effect of HCV on the alteration of DNA ploidy, which eventually leads to a recurrence of HCC after DAA treatment. In this review article, we will address some risk factors that could lead to the development/recurrence of HCC after treatment of HCV with DAA therapy, such as the role of liver cirrhosis, the alteration of DNA ploidy, the reactivation of hepatitis B virus (HBV), the role of cytokines and the alteration of the immune system, concomitant non- alcoholic fatty liver disease (NAFLD), obesity, alcohol consumption and also occult HCV infection/co-infection. Clinicians should be cautious considering that full eradication of hepatocarcinogenesis cannot be successfully accomplished by anti-HCV treatment alone.

Current Challenges in Vaccinology

The development of vaccines, which prime the immune system to respond to future infections, has led to global declines in morbidity and mortality from dreadful infectious communicable diseases. However, many pathogens of public health importance are highly complex and/or rapidly evolving, posing unique challenges to vaccine development. Several of these challenges include an incomplete understanding of how immunity develops, host and pathogen genetic variability, and an increased societal skepticism regarding vaccine safety. In particular, new high-dimensional omics technologies, aided by bioinformatics, are driving new vaccine development (vaccinomics). Informed by recent insights into pathogen biology, host genetic diversity, and immunology, the increasing use of genomic approaches is leading to new models and understanding of host immune system responses that may provide solutions in the rapid development of novel vaccine candidates.

Risk Factors Contributing to the Occurrence and Recurrence of Hepatocellular Carcinoma in Hepatitis C Virus Patients Treated with Direct-Acting Antivirals

Although hepatitis C virus (HCV) RNA may be eliminated from blood circulation by direct-acting antivirals (DAA) therapy as assessed by real-time polymerase chain reaction (PCR), HCV RNA can still be present in liver tissue, and this is known as occult HCV. There has been a lot of controversy surrounding the recurrence of hepatocellular carcinoma (HCC) after DAA treatment of hepatic cells infected with chronic HCV. One of the main risk factors that leads to de novo HCC is the chronicity of HCV in hepatic cells. There are many studies regarding the progression of HCV-infected hepatic cells to HCC. However, there is a lack of research on the different molecular mechanisms that lead to the progression of chronic HCV infection to HCC, as well as on the effect of HCV on the alteration of DNA ploidy, which eventually leads to a recurrence of HCC after DAA treatment. In this review article, we will address some risk factors that could lead to the development/recurrence of HCC after treatment of HCV with DAA therapy, such as the role of liver cirrhosis, the alteration of DNA ploidy, the reactivation of hepatitis B virus (HBV), the role of cytokines and the alteration of the immune system, concomitant non- alcoholic fatty liver disease (NAFLD), obesity, alcohol consumption and also occult HCV infection/co-infection. Clinicians should be cautious considering that full eradication of hepatocarcinogenesis cannot be successfully accomplished by anti-HCV treatment alone.

Innate Immune Response against Hepatitis C Virus: Targets for Vaccine Adjuvants

Despite successful treatments, hepatitis C virus (HCV) infections continue to be a significant world health problem. High treatment costs, the high number of undiagnosed individuals, and the difficulty to access to treatment, particularly in marginalized susceptible populations, make it improbable to achieve the global control of the virus in the absence of an effective preventive vaccine. Current vaccine development is mostly focused on weakly immunogenic subunits, such as surface glycoproteins or non-structural proteins, in the case of HCV. Adjuvants are critical components of vaccine formulations that increase immunogenic performance. As we learn more information about how adjuvants work, it is becoming clear that proper stimulation of innate immunity is crucial to achieving a successful immunization. Several hepatic cell types participate in the early innate immune response and the subsequent inflammation and activation of the adaptive response, principally hepatocytes, and antigen-presenting cells (Kupffer cells, and dendritic cells). Innate pattern recognition receptors on these cells, mainly toll-like receptors, are targets for new promising adjuvants. Moreover, complex adjuvants that stimulate different components of the innate immunity are showing encouraging results and are being incorporated in current vaccines. Recent studies on HCV-vaccine adjuvants have shown that the induction of a strong T- and B-cell immune response might be enhanced by choosing the right adjuvant.

HCV genotypes and their determinative role in hepatitis C treatment

Nowadays, exposure to infectious diseases caused by pathogenic viruses has become one of the major human concerns in health fields. In the meantime, hepatitis viruses are associated with health problems, especially in liver tissue. So far, several types of these viruses have been known including: HAV, HBV, HCV, HDV, HEV, and HGV. Nevertheless, it seems that hepatitis C is the major viral infection among all of the hepatitis infections. The cirrhosis and hepatocellular carcinoma are known as the most important pathological complications of this virus, from which seven genotypes have been identified. However, among these genotypes, the incidence rate of genotypes 1 and 3 is more than others. In this review, we have investigated the relationship between all HCV genotypes and therapeutic responses against them. Regarding heterogeneity between hepatitis C genotypes, it is not possible to access an effective vaccine against this virus, and treatment is the only applicable strategy. Response to treatment is different among genotypes, and it has resulted that each genotype has a specific therapeutic regimen of itself. Therefore, it seems that determination of hepatitis C genotype, as a key tool, is essential in controlling therapeutic regimen, improving local control programs and eventually producing an effective vaccine.

Association between Hepatitis C Virus Viremia and the rs12979860, rs2228145 and rs1800795 SNP (CT/AC/GG) Genotype in Saudi Kidney Transplant Recipients

Background:

Hepatitis C virus (HCV) is a major health problem, particularly in high-risk groups such as kidney transplant recipients, where it can adversely affect graft survival and increase the relative risk for mortality. Recently, the role of genetic variation among HCV patients in determining the outcome of infections has been under investigation.

Objective:

To investigate the association of single-nucleotide polymorphisms (SNPs) rs12979860 (located within the interleukin-28B locus), rs2228145 (interleukin-6 receptor) and rs1800795 (interleukin-6 promoter) with HCV viremia in renal transplant patients.

Materials and Methods:

In this analytical cross-sectional study, 149 kidney transplant recipients, 82 males (median age: 41 years) and 67 females (median age: 45 years), were screened for HCV RNA in blood using real-time polymerase chain reaction and genotyped by sequencing (rs12979860) and restriction fragment length polymorphism (rs2228145 and rs1800795).

Results:

HCV RNA was detected in 17 (11.41%) of the 149 patients. There was no statistically significant association between the studied SNPs and HCV viremia. However, a combination of the CT/AC/GG genotype was significantly associated with HCV viremia (odds ratio: 5.4). The genotype AA of rs2228145 in the IL-6 receptor was associated with viremia levels of >10⁵ copies/ml (odds ratio: 5.96).

Conclusion:

To the best of the authors' knowledge, this is the first study that has shown that the CT/AC/GG genotype has an impact on HCV viremia in kidney transplant patients. Therefore, such SNP genotypes may potentially be used to identify transplant patients at risk of HCV infection.

Clinical, Virological Characteristics, and Outcomes of Treatment with Sofosbuvir/Ledipasvir in Two Pediatric Patients Infected by HCV Genotype 4

Direct-acting antiviral drugs to cure infections with Hepatitis C virus (HCV) achieve a sustained virological response (SVR) in more than 90% of adult patients. At present, clinical trials are ongoing and real-life data are still limited in children. Herein, we report two cases of pediatric patients treated with fixed-dose combination of sofosbuvir/ledipasvir, already approved to treat HCV4 genotype. Both young girls achieved SVR even though HCV4 isolates carried L28M and M31L NS5A resistance-associated substitutions (RASs). Therefore, possible effects of these RASs merit further study, especially in children.