Risk factors for hepatocellular carcinoma associated with hepatitis C genotype 3 infection:A systematic review

BACKGROUND Hepatitis C virus(HCV)is a blood-borne virus which globally affects around 79 million people and is associated with high morbidity and mortality.Chronic infection leads to cirrhosis in a large proportion of patients and often causes hepatocellular carcinoma(HCC)in people with cirrhosis.Of the 6 HCV genotypes(G1-G6),genotype-3 accounts for 17.9%of infections.HCV genotype-3 responds least well to directly-acting antivirals and patients with genotype-3 infection are at increased risk of HCC even if they do not have cirrhosis.AIM To systematically review and critically appraise all risk factors for HCC secondary to HCV-G3 in all settings.Consequently,we studied possible risk factors for HCC due to HCV-G3 in the literature from 1946 to 2023.METHODS This systematic review aimed to synthesise existing and published studies of risk factors for HCC secondary to HCV genotype-3 and evaluate their strengths and limitations.We searched Web of Science,Medline,EMBASE,and CENTRAL for publications reporting risk factors for HCC due to HCV genotype-3 in all settings,1946-2023.RESULTS Four thousand one hundred and forty-four records were identified from the four databases with 260 records removed as duplicates.Three thousand eight hundred and eighty-four records were screened with 3514 excluded.Three hundred and seventy-one full-texts were assessed for eligibility with seven studies included for analysis.Of the seven studies,three studies were retrospective case-control trials,two retrospective cohort studies,one a prospective cohort study and one a cross-sectional study design.All were based in hospital settings with four in Pakistan,two in South Korea and one in the United States.The total number of participants were 9621 of which 167 developed HCC(1.7%).All seven studies found cirrhosis to be a risk factor for HCC secondary to HCV genotype-3 followed by higher age(five-studies),with two studies each showing male sex,high alpha feto-protein,directly-acting antivirals treatment and achievement of sustained virologic response as risk factors for developing HCC.CONCLUSION Although,studies have shown that HCV genotype-3 infection is an independent risk factor for end-stage liver disease,HCC,and liver-related death,there is a lack of evidence for specific risk factors for HCC secondary to HCV genotype-3.Only cirrhosis and age have demonstrated an association;however,the number of studies is very small,and more research is required to investigate risk factors for HCC secondary to HCV genotype-3.

Genotype 3-hepatitis C virus’last line of defense

Chronic infection with hepatitis C virus(HCV)is one of the leading causes of liver disease globally,affecting approximately 71 million people.The majority of them are infected with genotype(GT)1 but infections with GT3 are second in frequency.For many years,GT3 was considered to be less pathogenic compared to other GTs in the HCV family due to its favorable response to interferon(IFN)-based regimen.However,the growing evidence of a higher rate of steatosis,more rapid progression of liver fibrosis,and lower efficacy of antiviral treatment compared to infection with other HCV GTs has changed this conviction.This review presents the specifics of the course of GT3 infection and the development of therapeutic options for GT3-infected patients in the era of direct-acting antivirals(DAA).The way from a standard of care therapy with pegylated IFNalpha(pegIFNα)and ribavirin(RBV)through a triple combination of pegIFNα+RBV and DAA to the highly potent IFN-free pangenotypic DAA regimens is discussed along with some treatment options which appeared to be dead ends.Although the implementation of highly effective pangenotypic regimens is the most recent stage of revolution in the treatment of GT3 infection,there is still room for improvement,especially in patients with liver cirrhosis and those who fail to respond to DAA therapies,particularly those containing inhibitors of HCV nonstructural protein 5A.

Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

BACKGROUND Hepatitis C virus genotype 3a(HCV G3a)is highly prevalent in Pakistan.Due to the elevated cost of available Food and Drug Administration-approved drugs against HCV,medicinal natural products of potent antiviral activity should be screened for the cost-effective treatment of the disease.Furthermore,from natural products,active compounds against vital HCV proteins like non-structural protein 3(NS3)protease could be identified to prevent viral proliferation in the host.AIM To develop cost-effective HCV genotype 3a NS3 protease inhibitors from citrus fruit extracts.METHODS Full-length NS3 without co-factor non-structural protein 4A(NS4A)and codon optimized NS3 protease in fusion with NS4A were expressed in Escherichia coli.The expressed protein was purified by metal ion affinity chromatography and gel filtration.Citrus fruit extracts were screened using fluorescence resonance energy transfer(FRET)assay against the protease and polyphenols were identified as potential inhibitors using electrospray ionization-mass spectrometry(MS)/MS technique.Among different polyphenols,highly potent compounds were screened using molecular modeling approaches and consequently the most active compound was further evaluated against HCV NS4A-NS3 protease domain using FRET assay.RESULTS NS4A fused with NS3 protease domain gene was overexpressed and the purified protein yield was high in comparison to the lower yield of the full-length NS3 protein.Furthermore,in enzyme kinetic studies,NS4A fused with NS3 protease proved to be functionally active compared to full-length NS3.So it was concluded that co-factor NS4A fusion is essential for the purification of functionally active protease.FRET assay was developed and validated by the half maximal inhibitory concentration(IC50)values of commercially available inhibitors.Screening of citrus fruit extracts against the native purified fused NS4A-NS3 protease domain showed that the grapefruit mesocarp extract exhibits the highest percentage inhibition 91%of protease activity.Among the compounds identified by LCMS analysis,hesperidin showed strong binding affinity with the protease catalytic triad having S-score value of-10.98.CONCLUSION Fused NS4A-NS3 protease is functionally more active,which is effectively inhibited by hesperidin from the grapefruit mesocarp extract with an IC50 value of 23.32μmol/L.

Retraction Note:Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

Retraction note:Khan M,Rauf W,Habib F,Rahman M,Iqbal M.Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry.World J Hepatol 2020;12(11):976-992 PMID:33312423 DOI:10.4254/wjh.v12.i11.976.The online version of the original article can be found at https://www.wjgnet.com/1948-5182/full/v12/i11/976.htm.

Direct-acting Antiviral Regimens for Patients with Chronic Infection of Hepatitis C Virus Genotype 3 in China

Hepatitis C virus(HCV)genotype(GT)3 infection is associated with a more rapid hepatic disease progression than the other genotypes.Hence,early HCV clearance slows down the disease progression and is important for improving prognosis in GT3-infected patients.Nevertheless,compared with other genotypes,GT3 is difficult-to-treat with direct-acting antivirals,especially in the presence of cirrhosis.Current guidelines recommend several regimens which have been proven to be effective in GT3-infected patients from the Western world(North America,Europe,and Oceania).In China,GT3 infection comprises 8.7–11.7%of the 10 million patients infected with HCV and has strikingly different characteristics from that in Western countries.Unlike the Western countries,where GT3a is the predominant subtype,GT3a and 3b each affect roughly half of Chinese GT3-infected patients,with 94–96%of the GT3b-infected patients carrying A30K+L31M double NS5A resistance-associated substitutions.Phase 3 clinical trials including GT3b-infected patients have suggested that GT3b infection is difficult to cure,making the regimen choice for GT3b-infected patients an urgent clinical gap to be filled.This review includes discussions on the epidemiology of HCV GT3 in China,recommendations from guidelines,and clinical data from both Western countries and China.The aim is to provide knowledge that will elucidate the challenges in treating Chinese GT3-infected patients and propose potential solutions and future research directions.

Evaluation of an attenuated vaccine candidate based on the genotype C of bovine parainfluenza virus type 3 in albino guinea pigs

Bovine parainfluenza virus type 3（BPIV3） is considered as one of the most important respiratory tract pathogens of both young and adult cattle, and widespread among cattle in the world. BPIV3 was first reported in China in 2008 and four strains of BPIV3 were isolated from Shandong Province, known as genotype C（BPIV3c）. Pathogen investigations had shown that BPIV3 c infection was very common among cattle in China. To date, BPIV3 can be classified into genotypes A, B and C based on genetic and phylogenetic analysis. Serological survey also demonstrates that BPIV3 infection is widespread in China, however, there is still no available vaccine for BPIV3 prevention in China nowadays. In the present study, the BPIV3 c strain SD0835 was continuously passaged on Madin-Darby bovine kidney（MDBK） cells for hundreds of times, and the pathogenicity of passage 209 was reduced in guinea pigs. The passage 209 of BPIV3 c strain SD0835 was used as a live vaccine candidate to immunize the guinea pigs. The vaccination results revealed that two vaccinations could induce excellent serum neutralizing antibody responses as well as proliferation of T lymphocytes. The vaccinated guinea pigs were well protected against challenge with a low passage of BPIV3 c strain SD0835. Additionally, the percentages of CD4~＋ and CD8~＋ T cell subsets of animals in vaccinated group increased after immunization; T cell subsets on day 2 after challenge in both groups decreased, and the decline of CD4~＋ and CD8~＋ T cell subsets levels of four guinea pigs in vaccinated group was relatively moderate, comparing with that of the control group. These data support further testing of the attenuated virus as an effective candidate vaccine.

Preparation and immunoprotective effects of a virus-like particle candidate vaccine of the dominant epidemic D3 genotype coxsackievirus A6 in China

Coxsackievirus A6 of the D3a genotype(CVA6 D3a)is a primary pathogen causingmainland of China's hand,foot,and mouth disease(HFMD).Viral‐like particle(VLP)vaccines represent a potential candidate vaccine to prevent HFMD.This study collected Anti‐CVA6 D3a VLPs serum from BALB/c female mice immunized using CVA6 D3a VLPs.The neutralizing antibody levels were compared against the representative 14‐JX2018(D3a)and N4‐YN2015(D3b)strains between the antisera of different immune pathways.The immunoprotective effect of anti‐CVA6 D3a VLPs against these strains was monitored using pathological sections and immuno-histochemical results of lung and skeletal muscle tissues in seven‐day‐old Institute of Cancer Research(ICR)mice.Immunological protection against different branches of viruses was evaluated in 7‐day‐old(serum passive immune protection)and 14‐day‐old(VLPs active immune protection)neonatal ICR mice models.Serum‐neutralizing antibody levels were positively correlated with the number of immunizations and higher against 14‐JX2018 than against N4‐YN2015.Furthermore,these levels were significantly higher with abdominal injection than intramuscular injection.The immunized serum of 7‐day‐old ICR mice inoculated three times was 100%protected against CVA6 D3a 14‐JX2018(lethal titer:106.25 TCID 50)and CVA6 D3b N4‐YN2015(lethal titer:105.25TCID 50)fatal attacks,respectively.For ICR mice that have completed two active immunizations for 14 days,both CVA6 D3a 14‐JX2015(challenge titer:108.25 TCID 50)and CVA6 D3b N4‐YN2015(challenge titer:107.25 TCID 50)were used for the challenge,and the mice were able to survive.Overall,the CVA6 D3a VLPs prepared in this study are a potential vaccine candidate for CVA6,as it has the optimal protective effect against both CVA6 D3a and D3b evolutionary branches viruses.