Hepatitis C virus G1b infection decreases the number of small low-density lipoprotein particles.

AIM: To investigate how hepatitis C virus (HCV) G1b infection influences the particle number of lipoproteins. METHODS: The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV G1b infection (active HCV group) and 91 with cleared HCV infection (SVR group), were examined. Serum lipoprotein was fractionated by high-performance liquid chromatography into twenty fractions. The cholesterol and triglyceride concentrations in each fraction were measured using LipoSEARCH. The number of lipoprotein particles in each fraction was calculated using a newly developed algorithm, and the relationship between chronic HCV G1b infection and the lipoprotein particle number was determined by multiple linear regression analysis. RESULTS: The median number of low-density lipoprotein (LDL) particles was significantly lower in the active HCV group [1182 nmol/L, interquartile range (IQR): 444 nmol/L] than in the SVR group (1363 nmol/L, IQR: 472 nmol/L, P < 0.001), as was that of high-density lipoprotein (HDL) particles (14168 nmol/L vs 15054 nmol/L, IQR: 4114 nmol/L vs 3385 nmol/L, P = 0.042). The number of very low-density lipoprotein (VLDL) particles was similar between the two groups. Among the four LDL sub-fractions, the number of large LDL particles was similar between the two groups. However, the numbers of medium (median: 533.0 nmol/L, IQR: 214.7 nmol/L vs median: 633.5 nmol/L, IQR: 229.6 nmol/L, P < 0.001), small (median: 190.9 nmol/L, IQR: 152.4 nmol/L vs median: 263.2 nmol/L, IQR: 159.9 nmol/L; P < 0.001), and very small LDL particles (median: 103.5 nmol/L, IQR: 66.8 nmol/L vs median: 139.3 nmol/L, IQR: 67.3 nmol/L, P < 0.001) were significantly lower in the active HCV group than in the SVR group, respectively. Multiple linear regression analysis indicated an association between HCV G1b infection and the decreased numbers of medium, small, and very small LDL particles. However, active HCV infection did not affect the number of large LDL particles or any sub-fractions of VLDL and HDL particles. CONCLUSION: HCV G1b infection decreases the numbers of medium, small, and very small LDL particles.

High level of serum cholesteryl ester transfer protein in active hepatitis C virus infection.

AIM: To determine the significance of cholesteryl ester transfer protein (CETP) in lipoprotein abnormalities in chronic hepatitis C virus (HCV) infection. METHODS: We evaluated the significance of the serum concentration of CETP in 110 Japanese patients with chronic HCV infection. Fifty-five patients had active HCV infection, and HCV eradication had been achieved in 55. The role of CETP in serum lipoprotein abnormalities, specifically, in triglyceride (TG) concentrations in the four major classes of lipoproteins, was investigated using Pearson correlations in conjunction with multiple regression analysis and compared them between those with active HCV infection and those in whom eradication had been achieved. RESULTS: The serum CETP levels of patients with active HCV infection were significantly higher than those of patients in whom HCV eradication was achieved (mean ± SD, 2.84 ± 0.69 µg/mL vs 2.40 ± 1.00 µg/mL, P = 0.008). In multiple regression analysis, HCV infection status (active or eradicated) was an independent factor significantly associated with the serum CETP level. TG concentrations in low-density lipoprotein (mean ± SD, 36.25 ± 15.28 µg/mL vs 28.14 ± 9.94 µg/mL, P = 0.001) and high-density lipoprotein (HDL) (mean ± SD, 25.9 ± 7.34 µg/mL vs 17.17 ± 4.82 µg/mL, P < 0.001) were significantly higher in patients with active HCV infection than in those in whom HCV eradication was achieved. The CETP level was strongly correlated with HDL-TG in patients with active HCV infection (R = 0.557, P < 0.001), whereas CETP was not correlated with HDL-TG in patients in whom HCV eradication was achieved (R = -0.079, P = 0.56). CONCLUSION: Our results indicate that CETP plays a role in abnormalities of lipoprotein metabolism in patients with chronic HCV infection.

Centrilobular zonal necrosis as a hallmark of a distinctive subtype of autoimmune hepatitis.

BACKGROUND AND AIM: Centrilobular zonal necrosis (CZN) is a known histological variant of autoimmune hepatitis (AIH). However, the significance of CZN is yet to be fully elucidated. This study aimed to determine whether CZN is a hallmark of a distinctive subtype of AIH. METHODS: Histological changes in the centrilobular zones of liver biopsies from 113 AIH patients were assessed by a single pathologist and classified into three categories: typical zonal necrosis defined as CZN (15 patients); other necroinflammatory change (NIC; 24 patients); and absence of necrosis (non-NIC; 74 patients). The clinicopathological features and immunogenetic background of CZN patients were then assessed. RESULTS: The clinicopathological features of AIH with CZN were distinct from other types of AIH, including a higher frequency of acute onset, lower frequency of antinuclear antibodies, lower antinuclear antibody titers, lower serum immunoglobulin G levels, lower grade interface hepatitis, less prominent lymphoplasmacytic infiltration, and lower AIH score. Increased and decreased frequencies of HLA-DR9 and HLA-DR4, respectively, were identified as immunogenetic features of AIH with CZN. Conversely, the clinicopathological characteristics of AIH with NIC were similar to those of non-NIC AIH, including the majority of the AIH patients. The therapeutic outcomes of AIH with CZN were excellent when precise diagnoses were made without delay. CONCLUSION: The clinicopathological features and immunogenetic background of AIH with CZN differed from AIH without CZN. CZN may be a hallmark of a distinct subtype of AIH.

Chronic hepatitis C virus infection and lipoprotein metabolism.

Hepatitis C virus (HCV) is a hepatotrophic virus and a major cause of chronic liver disease, including hepatocellular carcinoma, worldwide. The life cycle of HCV is closely associated with the metabolism of lipids and lipoproteins. The main function of lipoproteins is transporting lipids throughout the body. Triglycerides, free cholesterol, cholesteryl esters, and phospholipids are the major components of the transported lipids. The pathway of HCV assembly and secretion is closely linked to lipoprotein production and secretion, and the infectivity of HCV particles largely depends on the interaction of lipoproteins. Moreover, HCV entry into hepatocytes is strongly influenced by lipoproteins. The key lipoprotein molecules mediating these interactions are apolipoproteins. Apolipoproteins are amphipathic proteins on the surface of a lipoprotein particle, which help stabilize lipoprotein structure. They perform a key role in lipoprotein metabolism by serving as receptor ligands, enzyme co-factors, and lipid transport carriers. Understanding the association between the life cycle of HCV and lipoprotein metabolism is important because each step of the life cycle of HCV that is associated with lipoprotein metabolism is a potential target for anti-HCV therapy. In this article, we first concisely review the nature of lipoprotein and its metabolism to better understand the complicated interaction of HCV with lipoprotein. Then, we review the outline of the processes of HCV assembly, secretion, and entry into hepatocytes, focusing on the association with lipoproteins. Finally, we discuss the clinical aspects of disturbed lipid/lipoprotein metabolism and the significance of dyslipoproteinemia in chronic HCV infection with regard to abnormal apolipoproteins.

Impact of Chronic Hepatitis C Virus Genotype 1b Infection on Triglyceride Concentration in Serum Lipoprotein Fractions.

Reduced low-density lipoprotein (LDL) cholesterol level is a characteristic feature of dyslipidemia in chronic hepatitis C virus (HCV) infection. However, abnormality in serum triglyceride (TG) has not been fully investigated. To clarify the impact of HCV genotype 1b (G1b) infection and advanced fibrosis on serum TG profiles, TG concentrations in lipoprotein fractions were examined in fasting sera from 185 subjects with active or cleared HCV infection by high-performance liquid chromatography. Serum lipoproteins were fractionated into four classes: chylomicron, very low-density lipoprotein (VLDL), LDL, and high-density lipoprotein (HDL). Then, the significance of HCV G1b infection on TG levels in each lipoprotein fraction was determined using multiple regression models. We found that active HCV G1b infection was positively associated with high HDL-TG levels and low VLDL-TG levels, independent of other factors included in the regression model. In VLDL sub-fractions, active HCV infection was only found to be associated with low levels of large VLDL-TG. Similarly, advanced liver fibrosis in chronic HCV G1b infection was associated with high levels of LDL-TG, HDL-TG, and small VLDL-TG, independent of other clinical factors. These findings indicate that active HCV G1b infection and advanced fibrosis are closely associated with abnormal serum TG profiles.

Interferon-λ3 polymorphisms in pegylated-interferon-α plus ribavirin therapy for genotype-2 chronic hepatitis C.

AIM: To evaluate interferon-λ3 (IFNL3) polymorphisms in response-guided pegylated interferon-α plus ribavirin (Peg-IFNα/RBV) therapy for genotype 2 (G2) chronic hepatitis C. METHODS: Between January 2006 and June 2012, a total of 180 patients with chronic infections of G2 hepatitis C virus (HCV) were treated with response-guided Peg-IFNα/RBV therapy. The treatment duration was 24 wk for patients who achieved rapid virologic response (RVR), and 36 or 48 wk for patients who did not. Then, the impact of the IFNL3 single nucleotide polymorphism genotype (TT/non-TT at rs8099917) on treatment outcomes was evaluated in the 180 patients, and between patients infected with either HCV sub-genotype 2a or 2b. RESULTS: Of the 180 patients evaluated, 111 achieved RVR, while the remaining 69 patients did not. In RVR patients, the sustained virologic response (SVR) rate was 96.4%, and the IFNL3 genotype did not influence the SVR rate (96.6% vs 95.8% in IFNL3 genotype TT vs non-TT). However, in non-RVR patients, the SVR rate decreased to 72.5% (P < 0.0001), and this rate was significantly different between the IFNL3 genotype TT and non-TT groups (80.0% vs 42.9%, P = 0.0146). Multivariate regression analysis in non-RVR patients identified the IFNL3 genotype TT as the only baseline-significant factor associated with SVR (OR = 5.39, 95%CI: 1.29-22.62; P = 0.0189). In analysis according to HCV sub-genotype, no significant difference in the SVR rate was found between HCV sub-genotypes 2a and 2b. CONCLUSION: In response-guided Peg-IFNα/RBV combination therapy for chronically HCV G2-infected patients, the impact of the IFNL3 genotype on SVR was limited to non-RVR patients.

Serum immunoreactive collagen IV detected by monoclonal antibodies as a marker of severe fibrosis in patients with non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. We evaluated serum collagen IV as a direct non-invasive marker of severe liver fibrosis in NAFLD. METHODS: The study included 148 NAFLD and 187 chronic hepatitis C patients in whom histological severity of liver fibrosis was evaluated. The utility of serum collagen IV measured by immune-mediated agglutination using two types of monoclonal antibodies for distinguishing severe fibrosis (≥ stage 3 and ≥ F3) from non-to-moderate fibrosis in NAFLD or chronic hepatitis C was assessed in comparison to serum hyaluronic acid or other indirect fibrosis markers. RESULTS: Multiple logistic regression analysis showed that serum collagen IV was significantly associated with severe fibrosis in NAFLD (odds ratio: 1.21, p<0.001) but not in chronic hepatitis C. For distinguishing severe fibrosis in NAFLD, collagen IV showed the largest area under the receiver-operating characteristic curve (0.827, 95%CI: 0.746-0.908) followed by FIB-4 (0.805, 95%CI: 0.728-0.890); in chronic hepatitis C, those for FIB-4 (0.813, 95%CI: 0.748-0.878) and collagen IV (0.770, 95%CI: 0.683-0.857) were the largest and smallest, respectively. To detect severe fibrosis in NAFLD, a cutoff of collagen IV > 177 exhibited 77.1% sensitivity, 84.0% specificity, 76.5% positive predictive value, and 84.0% negative predictive value. Combined with a cutoff of FIB-4 > 2.09, the negative and positive predictive values, and specificity for detecting severe fibrosis in NAFLD increased further. CONCLUSION: Collagen IV is a reliable marker for distinguishing severe liver fibrosis from non-to-moderate fibrosis in NAFLD but not chronic hepatitis C.

Aldehyde dehydrogenase 2 polymorphism for development to hepatocellular carcinoma in East Asian alcoholic liver cirrhosis.

BACKGROUND AND AIM: We aimed to clarify the influences of aldehyde dehydrogenase 2 (ALDH2), alcohol dehydrogenase 1B (ADH1B) polymorphisms, and ethanol consumption profile to hepatocellular carcinoma (HCC) development in alcoholic liver cirrhosis without chronic hepatitis B and C virus infection (non-B non-C). METHODS: Of 236 freshly diagnosed non-B non-C alcoholic liver cirrhosis patients, 67 were diagnosed as HCC and the remaining 169 as not having HCC. The relationship between the genetic polymorphisms and development to HCC were evaluated in well-matched patients with HCC (HCC group, n = 67) and without HCC (non-HCC group, n = 67) using propensity scores in age, sex, and prevalence of diabetes mellitus. RESULTS: Daily amount of ethanol consumption was significantly lower (P = 0.005), and consumptive period was significantly longer (P = 0.003) in HCC group than non-HCC group. Of 134 well-matched patients, 113 (84.3%) had ALDH2*1/*1 genotype and 21 (15.7%) had ALDH2*1/*2 genotype. In HCC development, consumptive long period (P = 0.007) and carrying ALDH2*1/*2 genotype (P = 0.026) were identified as significant factors independently participated, while there was no relation to ADH1B polymorphism. In addition, consumptive period was significantly longer in HCC group than non-HCC group in ALDH2*1/*1 genotype patients (P = 0.0005), while there was no difference in profile of ethanol consumption in ALDH2*1/*2 genotype patients. Among HCC group, daily (P = 3.78 × 10(-6) ) and cumulative amount (P = 4.89 × 10(-6) ) of ethanol consumption were significantly higher in ALDH2*1/*1 genotype patients than ALDH2*1/*2 genotype patients. CONCLUSION: In alcoholic liver cirrhosis, investigations of ALDH2 polymorphism and ethanol consumption profile are useful for prediction of HCC development.

Serum cytokeratin 18 fragment level as a noninvasive biomarker for non-alcoholic fatty liver disease.

BACKGROUND AND AIM: We evaluated the usefulness of serum cytokeratin 18 fragment (CK18-F) as a noninvasive biomarker in differentiating nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver (NAFL) since the prognosis of the 2 diseases differ. METHODS: 116 Japanese patients with nonalcoholic fatty liver disease (NAFLD) proven by liver biopsy were studied. Histological findings were classified according to the NAFLD activity score (NAS) proposed by the Nonalcoholic Steatohepatitis Clinical Research Network. The correlation between histological findings and serum CK18-F levels was investigated. RESULTS: Serum CK18-F levels showed a positive correlation with histologic steatosis (ρ = 0.271, P = 0.0033), inflammation (ρ = 0.353, P = 0.0005), ballooning (ρ = 0.372, P = 0.0001), and the total NAS (ρ = 0.474, P = 2.68 × 10-7). The serum CK18-F level was significantly lower for NAFL (NAS ≤ 2) than for borderline NASH (NAS of 3-4) or definite NASH (NAS ≥ 5) (P = 0.0294, P = 1.163 × 10-5, respectively). The serum CK18-F level was significantly higher for definite NASH than for borderline NASH (P = 0.0002). The area under the receiver operating characteristic curve of serum CK18-F to predict the presence of NAFL and definite NASH was 0.762 and 0.757, respectively. The optimal cut-off point of serum CK18-F for NAFL and definite NASH was 230 and 270 U/L, respectively. The sensitivity, specificity, positive predict value, and negative predict value of serum CK18-F for NAFL were 0.89, 0.65, 0.34, and 0.97, and those for definite NASH were 0.64, 0.76, 0.72, and 0.67, respectively. Accuracies of diagnosis for both NAFL and definite NASH were 0.70. CONCLUSIONS: Serum CK18-F could be a clinically useful biomarker to discriminate between NAFL and NASH.

A case of peripancreatic tuberculous lymphadenitis diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

Tuberculous lymphadenitis is a rare cause of obstructive jaundice. Here, we report the case of a 33-year-old male with obstructive jaundice caused by tuberculous lymphadenitis around the pancreatic head. The patient was born in China and had immigrated to Japan at 12 years of age. He presented with acute abdominal pain and jaundice. Findings from ultrasonography, computed tomography, and endoscopic retrograde cholangiopancreatography were suggestive of a stenosis of the distal common bile duct caused by multiple low-density masses around the pancreatic head with a contrast-enhanced solid rim. We successfully diagnosed the mass as tuberculous lymphadenitis using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The patient was treated with anti-tuberculous combination chemotherapy for 6 months, and subsequently exhibited clinical improvement. Thus, we found that EUS-FNA was a valuable minimally invasive method for diagnosing masses that cause icterus.

Early syphilitic hepatitis concomitant with nephrotic syndrome followed by acute kidney injury.

Although acute hepatitis and nephrotic syndrome are commonly reported as complications of tertiary syphilis, nephrotic syndrome concomitant with hepatitis in early-stage syphilis is rare. Here, we describe the case of a 46-year-old male who was diagnosed with acute liver dysfunction and nephrotic syndrome after presenting with general malaise, and who subsequently developed acute kidney injury. Laboratory examination showed alkaline phosphatase had a greater magnitude of elevation compared to alanine aminotransferase, suggesting the possibility of syphilitic hepatitis. The rapid plasmin regain test and Treponema pallidum hemagglutination assay were positive, supporting the presence of a syphilis infection. Additionally, liver biopsy examination showed infiltration of inflammatory cells into the portal area and epithelioid cell granulomas. Moreover, kidney biopsy examination by both optical and electron microscopy showed a congestion of neutrophils in the capillary vessels, structural collapse of the tubules, and subepithelial deposits under the epithelium of the glomerular endothelial cells. These pathological changes were consistent with those reported previously for early syphilitic hepatitis and nephrotic syndrome in early-stage syphilis. All the symptoms, including liver and renal dysfunction, resolved after benzyl penicillin treatment was initiated. Hence, we believe early-stage syphilis should be included in the differential diagnosis of unknown liver damage and/or nephrosis.

Assessment of the features of serum apolipoprotein profiles in chronic HCV infection: difference between HCV genotypes 1b and 2.

BACKGROUND: The life cycle of hepatitis C virus (HCV) is tightly associated with host lipoprotein metabolic pathways. Apolipoprotein is present on the outer surface of lipoprotein particles and plays an important role in lipoprotein metabolism. We aimed to elucidate the influence of chronic HCV infection on serum apolipoprotein profiles. METHODS: Fasting serum apolipoprotein profiles of 310 subjects with active or cleared HCV infection were examined. Subsequently, the association between chronic HCV infection and serum apolipoprotein levels was determined using multiple regression analysis. RESULTS: Active HCV infection was associated with high serum levels of apo A-II and low serum levels of apo C-II and C-III. HCV infection with both genotype 1b (G1b) and genotype 2 (G2) was associated with low serum levels of either apo C-II and C-III, whereas only HCV G1b infections caused elevated levels of apo A II and E. Among active HCV infections, HCV G1b was associated with an elevation in the serum apo E levels. Furthermore, IL28B non-major genotype (rs8099917 TG/GG) was associated with low levels of serum apo B and high levels of apoA-II, and advanced fibrosis was associated with low levels of apo B and C-II in G1b infection. CONCLUSIONS: Active HCV infection is distinctively associated with characteristic serum apolipoprotein profiles. The influence on apolipoprotein profiles varies with different HCV genotypes. Moreover, the genotype of IL28B and hepatic fibrosis affected serum apolipoproteins in G1b infection. Abnormalities in serum apolipoproteins may provide a clue to the elucidation of complex interactions between active HCV infection and lipid metabolism.

Elevation in Serum Concentration of Bone-Specific Alkaline Phosphatase without Elevation in Serum Creatinine Concentration Secondary to Adefovir Dipivoxil Therapy in Chronic Hepatitis B Virus Infection.

Of 168 patients with chronic hepatitis B virus (HBV) infection-related liver disease, 20 patients who had received 100 mg of lamivudine plus 10 mg/day of adefovir dipivoxil (ADV) (ADV group) and 124 patients who had received 0.5 mg/day of entecavir or 100 mg/day of lamivudine (non-ADV group) for >1 year were enrolled. For comparative analyses, 19 well-matched pairs were obtained from the groups by propensity scores. At the time of enrollment, serum creatinine and phosphate concentrations were similar between the ADV and non-ADV groups; however, urinary phosphate (P = 0.0424) and serum bone-specific alkaline phosphatase (BAP) (P = 0.0228) concentrations were significantly higher in the ADV group than in the non-ADV group. Serum BAP was significantly higher at the time of enrollment than before ADV administration in the ADV group (P = 0.0001), although there was no significant change in serum BAP concentration in the non-ADV group. There was a significant positive correlation between the period of ADV therapy and ΔBAP (R (2) = 0.2959, P = 0.0160). Serum BAP concentration increased before increase in serum creatinine concentration and was useful for early detection of adverse events and for developing adequate measures for continuing ADV for chronic HBV infection-related liver disease.

Serum lipoprotein profiles and response to pegylated interferon plus ribavirin combination therapy in patients with chronic HCV genotype 1b infection.

BACKGROUND: Abnormal serum lipid profiles have been noted in patients with chronic hepatitis C virus (HCV) infection. Moreover, many reports suggest that serum lipoprotein profiles are more profoundly distorted in patients with HCV G1b infection who have an unfavorable response to pegylated interferon (peg-IFN) plus ribavirin (RBV) combination therapy. However, after the discovery of single nucleotide polymorphisms near the IL28B gene (rs8099917 and rs12979860) as potent predictive factors affecting the response to peg-IFN plus RBV, lipid factors are thought to be confounding factors. OBJECTIVES: To re-examine the significance of lipoprotein profiles on virological response to peg-IFN plus RBV combination therapy in patients with chronic HCV G1b infection, we examined cholesterol and triglyceride concentrations in each lipoprotein fraction separated by high performance liquid chromatography. PATIENTS AND METHODS: Lipoprotein profiles were examined using fasting sera from 108 patients infected with HCV G1b who had chronic hepatitis, as determined by liver biopsy. Results of lipoprotein profiles and clinical data, including IL28B genotype and amino acid substitution at aa70 of HCV G1b, were compared between patients with a sustained virological response (SVR) and non-SVR or a non-virological response (NVR) and virological responses other than NVR (non-NVR). In addition, significant predictive factors independently associated with virological response to peg-IFNα-2b plus RBV were determined by logistic regression analysis. RESULTS: An increased ratio of cholesterol/triglyceride in very low-density lipoprotein (odds ratio (OR) 3.03; 95% confidence interval (CI) 1.01-9.44) along with a major genotype of rs8099917 (OR 9.09; 95% CI 2.94-33.33), were independent predictive factors for SVR. In contrast, lipid factors were not elucidated as independent predictive factors for NVR. CONCLUSIONS: Examination of the fasting lipid profile has clinical importance in predicting the efficacy of peg-IFN-α-2b plus RBV combination therapy for patients with HCV G1b even after the discovery of the IL28 genotype as a potent predictive factor.

New proposal for response-guided peg-interferon-plus-ribavirin combination therapy for chronic hepatitis C virus genotype 2 infection.

This study aimed to determine the most suitable duration of pegylated-interferon (Peg-IFN)-plus-ribavirin combination therapy in patients infected with hepatitis C virus (HCV) genotype 2 who had not achieved rapid virological response (serum HCV RNA disappearance after 4 weeks of therapy). HCV genotype 2 patients (n = 182) with a high viral load received >80% of the standard Peg-IFN-plus-ribavirin dose for at least 24 weeks, and their final virological responses were studied. Patients were classified into "rapid virological response" and "non-rapid virological response" groups. The non-rapid virological response group was further divided into a "virological response at 8 weeks" (serum HCV RNA disappearance after 8 weeks of therapy) and a "non-virological response at 8 weeks" group. Factors related to rapid virological response and optimal therapy duration in the non-rapid virological response group were evaluated. Multivariate logistic regression analysis showed that subtype HCV genotype 2a (P = 0.0015) and low concentration of pretreatment serum HCV RNA (P = 0.0058) were independent factors in a rapid virological response. In the virological response at 8 weeks group, the sustained virological response rate after 24 weeks of therapy was significantly lower than after 36 weeks (P = 0.044) or after 48 weeks (P = 0.006), and was similar for 36- and 48-weeks. The cost for achieving (CAS) one sustained virological response was lowest with 36-week therapy. Prolongation of Peg-IFN-plus-ribavirin combination therapy to 36 weeks is suitable for achieving virological response at 8 weeks, given the high, sustained virological response rate and cost benefit.