AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b ...AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b samples were ob- tained from Hong Kong patients who had completed the combined interferon-α/ribavirin treatment for more than one year with available response data. Nineteen of them were sustained virological responders, while 18 were non-responders. The amino acid sequences of the extended ISDR (eISDR) covering 64 amino acids upstream and 67 amino acids downstream from the previously reported ISDR were analyzed. RESULTS: One amino acid variation (I2268V, P = 0.023) was significantly correlated with treatment outcomein this pilot study with a limited number of patients, while two amino acid variations (R2260H, P = 0.05 and S2278T, P = 0.05) were weakly associated with treatment outcome. The extent of amino acid variations within the ISDR or eISDR was not correlated with treatment outcome as previously reported. CONCLUSION: Three amino acid mutations near but outside of ISDR may associate with interferon treatment resistance of HCV-1b patients in Hong Kong.展开更多
AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Althou...AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.展开更多
Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a b...Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a broad spectrum of pathogenicity,such as lipid and glucose metabolism disorders and hepatocellular carcinoma development.The HCV genome is characterized by a high degree of genetic diversity,which can be associated with viral sensitivity or resistance(reflected by different virological responses)to interferon(IFN)-based therapy.In this regard,it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome.In particular,among the HCV proteins,the core and nonstructural proteins(NS)5A have been extensively studied for their correlation with responses to IFN-based treatment.This review aims to cover updated information on the impact of major HCV genetic factors,including HCV genotype,mutations in amino acids 70 and91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A,on virological responses to IFN-based therapy.展开更多
AIM To determine the number of mutations in the NS5 A region of the hepatitis C virus(HCV) and its relationship to the response to antiviral therapy in patients with chronic hepatitis C genotype 1 who are non-responde...AIM To determine the number of mutations in the NS5 A region of the hepatitis C virus(HCV) and its relationship to the response to antiviral therapy in patients with chronic hepatitis C genotype 1 who are non-responders to two or more treatments. METHODS Sequences within HCV NS5 A [PKR binding domain(PKRBD) and the interferon-sensitivity-determining region(ISDR)] were analysed via direct sequencing in a selected cohort of 72 patients, with a total of 201 treatments [interferon-alpha(IFN-α), n = 49; IFN-α + ribavirin(RBV), n = 75; pegylated(peg) IFN-α + RBV, n = 47; first-generation direct-acting antivirals(DAAs), n = 13; and second-generation DAAs, n = 17]. Of these, 48/201 achieved a sustained virological response(SVR) and 153/201 achieved no virological response(NVR).RESULTS For both regions, treatments resulting in SVR were associated with more baseline mutations than were treatments resulting in NVR(SVR vs NVR; PKRBD: 5.82 ± 3 vs 4.86 ± 2 mutations, P = 0.045; ISDR: 2.65 ± 2 vs 1.51 ± 1.7 mutations, P = 0.005). A decrease or no change in the number of mutations over time between treatments in the PKRBD or ISDR, as shown by sequencing, was associated with patients who usually failed to respond to treatment(PKRBD, P = 0.02; ISDR, P = 0.001). Moreover, patients showing a post-treatment baseline viral load > 600000 IU/m L and increased ISDR mutations with respect to the previous treatment were 9.21 times more likely to achieve SVR(P = 0.001). CONCLUSION The obtained results show that among patients who have shown no response to two or more antiviral treatments, the likelihood of achieving SVR increases with the genetic variability in the ISDR region(≥ 2 mutations or number of substitutions from the HCV-J and HCV-1 prototype), especially when the viral load is greater than 600000 IU/m L.展开更多
AIM: To determine the role of interferon (IFN) with or without ribavirin in preventing or delaying hepatocellular carcinoma (HCC) development in patients with hepatitis C virus (HCV) related cirrhosis. Data on the pre...AIM: To determine the role of interferon (IFN) with or without ribavirin in preventing or delaying hepatocellular carcinoma (HCC) development in patients with hepatitis C virus (HCV) related cirrhosis. Data on the preventive effect of IFN plus ribavirin treatment are lacking.METHODS: A total of 101 patients (62 males and 39 females, mean age 55.1:1:1.4 years) with histologically proven HCV related liver cirrhosis plus compatible biochemistry and ultrasonography were enrolled in the study. Biochemistry and ultrasonography were performed every 6 too. Ultrasound guided liver biopsy was performed on all detected focal lesions. Follow-up lasted for 5 years. Cellular proliferation, evaluated by measuring Ag-NOR proteins in hepatocytes nuclei, was expressed as AgNOR-Proliferative index (AgNOR-PI) (cut-off = 2.5). Forty-one patients (27 males, 14 females) were only followed up after the end of an yearly treatment with IFN-alpha2b (old treatment control group = OTCG). Sixty naive patients were stratified according to sex and AgNOR-PI and then randomized in two groups: 30 were treated with IFN-alpha2b + ribavirin (treatment group=TG), the remaining were not treated (control group=CG). Nonresponders (NR) or relapsers in the TG received further IFN/ribavirin treatments after a 6 mo of withdrawal. RESULTS: AgNOR-PI was significantly lowered by IFN (P<0.001). HCC incidence was higher in patients with AgNOR-PI>2.5 (26% vs3%, P<0.01). Two NR in the OTCG, none in the TG and 9 patients in the CG developed HCC during follow-up. The Kaplan-Mayer survival curves showed statistically significant differences both between OTCG and CG (P<0.004) and between TG and CG (P<0.003). CONCLUSION: IFN/ribavirin treatment associated with retreatment courses of NR seems to produce the best results in terms of HCC prevention. AgNOR-PI is a useful marker of possible HCC development.展开更多
基金Supported by The National Key Technology Research and Development Program of China, No. 2009ZX10004-104
文摘AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b samples were ob- tained from Hong Kong patients who had completed the combined interferon-α/ribavirin treatment for more than one year with available response data. Nineteen of them were sustained virological responders, while 18 were non-responders. The amino acid sequences of the extended ISDR (eISDR) covering 64 amino acids upstream and 67 amino acids downstream from the previously reported ISDR were analyzed. RESULTS: One amino acid variation (I2268V, P = 0.023) was significantly correlated with treatment outcomein this pilot study with a limited number of patients, while two amino acid variations (R2260H, P = 0.05 and S2278T, P = 0.05) were weakly associated with treatment outcome. The extent of amino acid variations within the ISDR or eISDR was not correlated with treatment outcome as previously reported. CONCLUSION: Three amino acid mutations near but outside of ISDR may associate with interferon treatment resistance of HCV-1b patients in Hong Kong.
基金Supported by a grant from l’Agence National de la Recherche sur le Sida (ANRS grant 2001/011)
文摘AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.
基金Supported by A Health and Labour Sciences Research Grant from the Ministry of Health,Labour and Welfare,Japan,a SATREPS Grant from Japan Science and Technology Agency and Japan International Cooperation Agencythe Japan Initiative for Global Research Network on Infectious Diseases(J-GRID)program from the Ministry of Education,Culture,Sports,Science and Technology,Japan
文摘Hepatitis C virus(HCV)is a major cause of liver disease worldwide.HCV is able to evade host defense mechanisms,including both innate and acquired immune responses,to establish persistent infection,which results in a broad spectrum of pathogenicity,such as lipid and glucose metabolism disorders and hepatocellular carcinoma development.The HCV genome is characterized by a high degree of genetic diversity,which can be associated with viral sensitivity or resistance(reflected by different virological responses)to interferon(IFN)-based therapy.In this regard,it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome.In particular,among the HCV proteins,the core and nonstructural proteins(NS)5A have been extensively studied for their correlation with responses to IFN-based treatment.This review aims to cover updated information on the impact of major HCV genetic factors,including HCV genotype,mutations in amino acids 70 and91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A,on virological responses to IFN-based therapy.
基金Supported by“Consejería de Salud de la Junta de Andalucía”,No.PI0137/07“Instituto de Salud CarlosⅢ”,No.FISIntrasalud PI010/717
文摘AIM To determine the number of mutations in the NS5 A region of the hepatitis C virus(HCV) and its relationship to the response to antiviral therapy in patients with chronic hepatitis C genotype 1 who are non-responders to two or more treatments. METHODS Sequences within HCV NS5 A [PKR binding domain(PKRBD) and the interferon-sensitivity-determining region(ISDR)] were analysed via direct sequencing in a selected cohort of 72 patients, with a total of 201 treatments [interferon-alpha(IFN-α), n = 49; IFN-α + ribavirin(RBV), n = 75; pegylated(peg) IFN-α + RBV, n = 47; first-generation direct-acting antivirals(DAAs), n = 13; and second-generation DAAs, n = 17]. Of these, 48/201 achieved a sustained virological response(SVR) and 153/201 achieved no virological response(NVR).RESULTS For both regions, treatments resulting in SVR were associated with more baseline mutations than were treatments resulting in NVR(SVR vs NVR; PKRBD: 5.82 ± 3 vs 4.86 ± 2 mutations, P = 0.045; ISDR: 2.65 ± 2 vs 1.51 ± 1.7 mutations, P = 0.005). A decrease or no change in the number of mutations over time between treatments in the PKRBD or ISDR, as shown by sequencing, was associated with patients who usually failed to respond to treatment(PKRBD, P = 0.02; ISDR, P = 0.001). Moreover, patients showing a post-treatment baseline viral load > 600000 IU/m L and increased ISDR mutations with respect to the previous treatment were 9.21 times more likely to achieve SVR(P = 0.001). CONCLUSION The obtained results show that among patients who have shown no response to two or more antiviral treatments, the likelihood of achieving SVR increases with the genetic variability in the ISDR region(≥ 2 mutations or number of substitutions from the HCV-J and HCV-1 prototype), especially when the viral load is greater than 600000 IU/m L.
文摘AIM: To determine the role of interferon (IFN) with or without ribavirin in preventing or delaying hepatocellular carcinoma (HCC) development in patients with hepatitis C virus (HCV) related cirrhosis. Data on the preventive effect of IFN plus ribavirin treatment are lacking.METHODS: A total of 101 patients (62 males and 39 females, mean age 55.1:1:1.4 years) with histologically proven HCV related liver cirrhosis plus compatible biochemistry and ultrasonography were enrolled in the study. Biochemistry and ultrasonography were performed every 6 too. Ultrasound guided liver biopsy was performed on all detected focal lesions. Follow-up lasted for 5 years. Cellular proliferation, evaluated by measuring Ag-NOR proteins in hepatocytes nuclei, was expressed as AgNOR-Proliferative index (AgNOR-PI) (cut-off = 2.5). Forty-one patients (27 males, 14 females) were only followed up after the end of an yearly treatment with IFN-alpha2b (old treatment control group = OTCG). Sixty naive patients were stratified according to sex and AgNOR-PI and then randomized in two groups: 30 were treated with IFN-alpha2b + ribavirin (treatment group=TG), the remaining were not treated (control group=CG). Nonresponders (NR) or relapsers in the TG received further IFN/ribavirin treatments after a 6 mo of withdrawal. RESULTS: AgNOR-PI was significantly lowered by IFN (P<0.001). HCC incidence was higher in patients with AgNOR-PI>2.5 (26% vs3%, P<0.01). Two NR in the OTCG, none in the TG and 9 patients in the CG developed HCC during follow-up. The Kaplan-Mayer survival curves showed statistically significant differences both between OTCG and CG (P<0.004) and between TG and CG (P<0.003). CONCLUSION: IFN/ribavirin treatment associated with retreatment courses of NR seems to produce the best results in terms of HCC prevention. AgNOR-PI is a useful marker of possible HCC development.
