Review article: management of patients with chronic hepatitis C virus infection and "normal" alanine aminotransferase activity

A people-centered decentralized outreach model toward HCV micro-elimination in hyperendemic areas: COMPACT study in SARS Co-V2 pandemic

OBJECTIVES

Gaps in linkage-to-care remain the barriers toward hepatitis C virus (HCV) elimination in the directly-acting-antivirals (DAA) era, especially during SARS Co-V2 pandemics. We established an outreach project to target HCV micro-elimination in HCV-hyperendemic villages.

METHODS

The COMPACT provided "door-by-door" screening by an "outreach HCV-checkpoint team" and an "outreach HCV-care team" for HCV diagnosis, assessment and DAA therapy in Chidong/Chikan villages between 2019 and 2021. Participants from neighboring villages served as Control group.

RESULTS

A total of 5731 adult residents participated in the project. Anti-HCV prevalence rate was 24.0% (886/3684) in Target Group and 9.5% (194/2047) in Control group (P < 0.001). The HCV-viremic rates among anti-HCV-positive subjects were 42.7% and 41.2%, respectively, in Target and Control groups. After COMPACT engagement, 80.4% (304/378) HCV-viremic subjects in the Target group were successfully linked-to-care, and Control group (70% (56/80), P = 0.039). The rates of link-to-treatment and SVR12 were comparable between Target (100% and 97.4%, respectively) and Control (100% and 96.4%) groups. The community effectiveness was 76.4% in the COMPACT campaign, significantly higher in Target group than in Control group (78.3% versus 67.5%, P = 0.039). The community effectiveness decreased significantly during SARS Co-V2 pandemic in Control group (from 81% to 31.8%, P < 0.001), but not in Target group (80.3% vs. 71.6%, P = 0.104).

CONCLUSIONS

The outreach door-by-door screen strategy with decentralized onsite treatment programs greatly improved HCV care cascade in HCV-hyperendemic areas, a model for HCV elimination in high-risk marginalized communities in SARS Co-V2 pandemic.

Natural History of Hepatic and Extrahepatic Hepatitis C Virus Diseases and Impact of Interferon-Free HCV Therapy

The hepatitis C virus (HCV) infects 71.1 million persons and causes 400,000 deaths annually worldwide. HCV mostly infects the liver, causing acute and chronic necroinflammatory damage, which may progress toward cirrhosis and hepatocellular carcinoma. In addition, HCV has been associated with several extrahepatic manifestations. The advent of safe and effective direct-acting antivirals (DAAs) has made the dream of eliminating this public health scourge feasible in the medium term. Prospective studies using DAA-based regimens have shown the benefit of HCV clearance in terms of both liver- and non-liver-related mortality.

Hepatitis C virus load in parenchyma cells correlates with hepatic injury in infected patients

The association between serum hepatitis C virus (HCV) load and hepatic injury in HCV-infected patients has been extensively investigated. The present study aimed to investigate the association between HCV load in hepatic parenchyma cells and hepatic injury in HCV-infected patients. A total of 56 HCV-infected patients were included in the present retrospective study. The serum HCV mRNA was determined using quantitative polymerase chain reaction, while the hepatic parenchyma cell volume and HCV mRNA in hepatic parenchyma cells were also determined. Hepatic injury was evaluated on the basis of the severity of inflammation and fibrosis. The results demonstrated that there were evident differences in the mean serum HCV RNA levels and the HCV load/parenchyma cell volume among the various grades of hepatic inflammation (G1-G4) when groups with the least and most inflammation were compared (G1 vs. G4; P<0.05). Significant differences in the HCV load existed between groups divided according to the fibrosis grade; in addition, differences existed between fibrosis grades S1 and S2, and S2 and S4 when comparing serum HCV RNA levels (P<0.05). Similarly, differences existed between every two fibrosis stages (S0 vs. S4, S2 vs. S3, and S2 vs. S4; P<0.05) when viral loads and parenchyma cell volumes were compared (F=2.860, P<0.05). Furthermore, the fibrosis staging was correlated with the viral load/parenchyma cell volume (F=2.670, P<0.05). In conclusion, hepatic fibrosis grade was found to be associated with HCV load in parenchyma cells. The results of the present study demonstrated that the viral load in parenchyma cells is a more appropriate index compared with the serum viral load for evaluating HCV replication in hepatocytes, and may function as an important factor in HCV-infected hepatic injury evaluation.

Histological and clinical characteristics of patients with chronic hepatitis C and persistently normal alanine aminotransferase levels

Patients with chronic hepatitis C virus (HCV) infection and persistently normal alanine aminotransferase (PNALT) are generally described to have mild liver disease. The aim of this study was to compare clinical and histological features in HCV-infected patients with PNALT and elevated ALT. Patients presenting to the University of Illinois Medical Center, Chicago, who had biopsy proven HCV, an ALT measurement at the time of liver biopsy, at least one additional ALT measurement over the next 12 months, and liver biopsy slides available for review were identified. PNALT was defined as ALT ≤ 30 on at least 2 different occasions over 12 months. Of 1200 patients with HCV, 243 met the study criteria. 13% (32/243) of patients had PNALT while 87% (211/243) had elevated ALT. Significantly more patients with PNALT had advanced fibrosis (F3 and F4) compared to those with elevated ALT (P = 0.007). There was no significant difference in the histology activity index score as well as mean inflammatory score between the two groups. In conclusion, in a well-characterized cohort of patients at a tertiary medical center, PNALT did not distinguish patients with mild liver disease.

Hepatitis C genotype 4 with normal transaminases: correlation with fibrosis and response to treatment, a cohort Egyptian study of 4277 patients

BACKGROUND AND OBJECTIVE

Chronic hepatitis C virus (HCV) patients with persistently normal transaminases represent a subgroup of patients with mild, slowly progressive disease, natural history, and optimal management of these patients needs to be investigated in Egypt. Our aim is to assess the severity of hepatic fibrosis and response to therapy in a cohort of Egyptian HCV patients with normal transaminases.

PATIENTS AND METHODS

Retrospective demographics, laboratory, histological features and treatment outcome of patients included in the national program for the control of viral hepatitis in Egypt since 2007 were collected. Combined pegylated IFN/ribavirin therapy was given for patients with fibrosis stage ≥ F1 and elevated transaminases while those with normal transaminase; therapy was initiated only in patients with fibrosis stage ≥ F2.

RESULTS

Normal ALT and AST were detected in 1308/4277 (30.6%) and 1662/4277 (38.9%) patients, respectively, while both enzymes were normal in 943 patients (22%). Multivariate regression analysis showed that lower AFP and higher platelets count (compared with elevated transaminases group) were significantly correlated with normal transaminases (P<0.01), however, HCV-RNA levels did not show such significance. The number of patients with HAI score ≥ A1 was significantly lower in normal than elevated transaminases (36.5% vs 40.9%, respectively, P<0.01) and patients with fibrosis ≥ F2 was significantly lower in normal than elevated transaminases (36.4%) and (43%), respectively (P<0.01). There was no significant correlation between baseline transaminases levels and response to treatment.

CONCLUSION

Normal transaminases are frequently encountered in chronic HCV Egyptian patients (22%). They show low AFP level, mild degree of activity and stage of fibrosis with no correlation with response to therapy.

Liver fatty acid-binding protein is a diagnostic marker to detect liver injury due to chronic hepatitis C infection

BACKGROUND AND AIMS

Liver fatty acid-binding protein (L-FABP) is a small molecule. The aim of this study was to examine L-FABP levels and to detect its diagnostic value in chronic hepatitis C (CHC).

METHODS

We studied 22 patients with CHC and 20 healthy control subjects. Patients with persistently elevated serum aminotransferases and positive HCV RNA were included in the study. Patients with CHC underwent percutaneous liver biopsy. Serum level of L-FABP was determined by ELISA method.

RESULTS

Patients with CHC had significantly increased levels of L-FABP compared to controls. A strong correlation between serum L-FABP concentrations and aspartate aminotransferases, alanine aminotransferases, HCV RNA levels and hepatic inflammation was found. When a cut-off value was 29,000 pg/mL for L-FABP, sensitivity and specificity were 75 and 100%, respectively. Positive and negative predictive values for L-FABP were 100 and 78%, respectively.

CONCLUSIONS

Serum L-FABP is used as a new diagnostic marker to detect liver injury.

Accessing Hepatitis C patients who are difficult to reach: it is time to overcome barriers

With the arrival of simple, efficient and safe interferon-free treatment regimens, hepatitis C virus (HCV) therapy will have the potential to be successfully used for the majority of infected patients and prevent the associated morbidity and mortality. With the current treatment uptake rates, only a very small proportion of HCV-infected patients are reached. Paradoxically, treatment rates are lowest in the most affected at-risk group - people who inject drugs (PWID) - which is the major driving force behind the spread of HCV infection. To conquer the increasing problem of HCV-related liver disease, many existing but modifiable obstacles, which prevent detection, assessment and treatment uptake, have to be overcome in this population. This review article summarizes the existing literature on the most relevant barriers preventing HCV care and describes measures to overcome these obstacles.

Peginterferon alpha-2a and ribavirin in patients with hepatitis C virus genotype 1 infection with persistently normal alanine aminotransferase levels

BACKGROUND AND AIM

To evaluate the efficacy and safety of peginterferon α-2a plus ribavirin at standard doses in patients with hepatitis C virus (HVC) genotype 1 infection with persistently normal alanine aminotransferase (ALT) levels.

METHODS

Patients aged 18 to 65 years were included in this observational, prospective study if they had evidence of a HCV genotype 1 infection. The serum HCV RNA concentration was determined at baseline and week 12. A qualitative HCV RNA test was performed at baseline and at weeks 48 and 72. Liver function tests were performed at each study visit. The primary efficacy measure was the sustained virological response in the intention-to-treat population. Logistic regression analyses were also performed to explore predictors of virological response.

RESULTS

A sustained virological response was observed in 100 of the 175 patients (57%). An early virological response and end-of-treatment response were seen in 159 patients (91%) and 133 patients (76%), respectively. Thirty-seven of the 122 evaluable patients for this outcome (30%) showed a rapid virological response. A higher viral load was a significant predictor for a lack of rapid virological response and lack of sustained virological response. There were not any unexpected safety or tolerability findings.

CONCLUSIONS

Our study suggests that the efficacy of the combination of peginterferon α-2a and ribavirin in patients with HCV genotype 1 infection and normal ALT levels is at least similar to that reported in patients with elevated ALT levels.

Liver fibrosis progression in HIV/hepatitis C virus coinfected patients with normal aminotransferases levels

INTRODUCTION: Approximately 30% of hepatitis C virus (HCV) monoinfected patients present persistently normal alanine aminotransferase (ALT) levels. Most of these patients have a slow progression of liver fibrosis. Studies have demonstrated the rate of liver fibrosis progression in hepatitis C virus-human immunodeficiency virus (HCV-HIV) coinfected patients is faster than in patients infected only by HCV. Few studies have evaluated the histological features of chronic hepatitis C in HIV-infected patients with normal ALT levels. METHODS: HCV-HIV coinfected patients (HCV-RNA and anti-HIV positive) with known time of HCV infection (intravenous drugs users) were selected. Patients with hepatitis B surface antigen (HBsAg) positive or hepatitis C treatment before liver biopsy were excluded. Patients were considered to have a normal ALT levels if they had at least 3 normal determinations in the previous 6 months prior to liver biopsy. All patients were submitted to liver biopsy and METAVIR scale was used. RESULTS: Of 50 studied patients 40 (80%) were males. All patients were treated with antiretroviral therapy. The ALT levels were normal in 13 (26%) patients. HCV-HIV co-infected patients with normal ALT levels had presented means of the liver fibrosis stages (0.77±0.44 versus 1.86±1.38; p<0.001) periportal inflammatory activity (0.62±0.77 versus 2.24±1.35; p<0.001) and liver fibrosis progression rate (0.058±0.043 fibrosis unit/year versus 0.118±0.102 fibrosis unit/year) significantly lower as compared to those with elevated ALT. CONCLUSIONS: HCV-HIV coinfected patients with persistently normal ALTs showed slower progression of liver fibrosis. In these patients the development of liver cirrhosis is improbable.

Should we treat HCV carriers with normal ALT levels? The '5Ws' dilemma

Approximately 30% of patients with chronic HCV infection have persistently normal ALT levels. Although formerly referred to as 'healthy' or 'asymptomatic' HCV carriers, and thus historically excluded from antiviral treatment, it has now become clear that the majority of these patients have some degree of histological liver damage that may be significant in up to 20% of cases and might progress towards a more severe degree of liver fibrosis. A significant proportion of patients experience periods of increased serum ALT associated with enhanced disease progression. However, controversies still exist in clinical practice regarding the definition of 'persistent' ALT normality, the virological and histological features of these subjects, the need for liver biopsy, the role of noninvasive tools for the assessment of liver fibrosis, the natural history and the usefulness of antiviral treatment. The advent of new therapeutic options (pegylated interferon plus ribavirin) has shifted treatment targets towards the eradication of underlying infection, with therapy decision based on age, severity of disease and likelihood of response rather than on aminotransferase levels. This review is aimed at approaching the main unresolved issues on this topic, trying to give evidence-based answers to the more frequently asked questions from patients and their physicians.

APASL consensus statements and management algorithms for hepatitis C virus infection

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the "APASL Consensus Statements and Management Algorithms for Hepatitis C Virus Infection" in December, 2010, in order to revise "Asian Pacific Association for the Study of the Liver consensus statements on the diagnosis, management and treatment of hepatitis C virus infection (J Gastroenterol Hepatol 22:615-633, 2007)". The working party consisted of expert hepatologists from the Asian-Pacific region gathered at Makuhari, Chiba, Japan on 19 December 2010. New data were presented, discussed and debated to draft a revision. Participants of the consensus meeting assessed the quality of cited studies. Finalized recommendations are presented in this review.

Rapid virological response as a predictor of sustained response in HCV-infected patients with persistently normal alanine aminotransferase levels: A multicenter study

Rapid virological response (RVR) is now considered the strongest predictor of sustained virological response (SVR) in patients with HCV undergoing antiviral treatment, and thus, shorter antiviral treatment for these patients has been suggested. However, no data exist on the predictive value of RVR in HCV carriers with normal ALT values. A total of 137 patients with persistently normal ALT treated with peginterferon alfa 2a and ribavirin were studied. Fifteen patients dropped out early because of side effects, and in 10 patients with HCV-1 treatment was discontinued because of lack of early virological response (EVR). RVR was observed in 68% of the patients (42% patients with HCV-1, 90% HCV-2 and 64% HCV-3). An end-of-treatment response was observed in 86% of the patients (68% HCV-1, 100% HCV-2 and 91% HCV-3). SVR was maintained in 91 patients (46% HCV-1, 97% HCV-2 and 82% HCV-3). Overall, 92% patients with rapid response did obtain HCV eradication vs only 38% of those without rapid response. HCV-1 patients with baseline HCV RNA <400×10(3) IU/mL were more likely to achieve RVR and SVR than those with higher HCV RNA levels. We conclude that patients with genotype 1 and normal ALT who achieve HCV RNA negativity at week 4 may have a higher probability of eradicating their infection. Because of the concomitant favourable demographic and virological features often found in this particular subset of patients, the duration of therapy in these people might be shortened in the case of RVR. Persistently normal alanine aminotransferase levels patients with genotype 2 or 3 have a high chance of achieving SVR, so retesting of HCV RNA during treatment may have no additional practical value in these subjects.

European guideline for the management of hepatitis B and C virus infections, 2010

These are the guidelines on hepatitis B and C management for IUSTI/WHO in Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of hepatitis B and C with particular reference to sexual health clinical practice.

HCV carriers with normal alanine aminotransferase levels: healthy persons or severely ill patients? Dealing with an everyday clinical problem

Approximately 30% of patients with chronic HCV infection show persistently normal ALT levels. Although formerly referred to as 'healthy' or 'asymptomatic' HCV carriers, and thus historically excluded from antiviral treatment, it has now become clear that the majority of these patients have some degree of histological liver damage that may be significant in up to 20% of patients and might progress toward a more severe degree of liver fibrosis. A significant proportion of patients (> or =20%) experience periods of increased serum ALT (flare) associated with enhanced disease progression. However, controversies still exist in clinical practice regarding the definition of 'persistent' ALT normality, the virological and histological features of these subjects, the need for liver biopsy, the role of non invasive tools for the assessment of liver fibrosis (transient hepatic elastography, fibroscan), and the natural history and optimal management of chronic hepatitis C with normal ALT. The advent of new therapeutic options (pegylated interferons plus ribavirin) has shifted treatment targets toward eradication of underlying infection, with therapy decision based on age, severity of disease and likelihood of response rather than on aminotransferase levels. This review does approach the main unresolved issues on this topic in the form of a dialog between a hepatologist and a patient with HCV infection but normal alanine aminotransferase levels, trying to give evidence-based answers to the more frequently asked questions from patients and their physicians.

Practice guidelines for the diagnosis and management of nonalcoholic fatty liver disease. A decalogue from the Italian Association for the Study of the Liver (AISF) Expert Committee

We report the evidence-based Italian Association for the Study of Liver guidelines for the appropriate diagnosis and management of patients with nonalcoholic fatty liver disease in clinical practice and its related research agenda. The prevalence of nonalcoholic fatty liver disease varies according to age, gender and ethnicity. In the general population, the prevalence of nonalcoholic fatty liver disease is about 25% and the incidence is of two new cases/100 people/year. 2-3% of individuals in the general population will suffer from nonalcoholic steatohepatitis. Uncomplicated steatosis will usually follow a benign course. Individuals with nonalcoholic steatohepatitis, however, have a reduced life expectancy, mainly owing to vascular diseases and liver-related causes. Moreover, steatosis has deleterious effects on the natural history of HCV infection. Nonalcoholic fatty liver disease is usually diagnosed in asymptomatic patients prompted by the occasional discovery of increased liver enzymes and/or of ultrasonographic steatosis. Medical history, complete physical examination, etiologic screening of liver injury, liver biochemistry tests, serum lipids and insulin sensitivity tests should be performed in every patient. Occult alcohol abuse should be ruled out. Ultrasonography is the first-line imaging technique. Liver biopsy, the gold standard in diagnosis and prognosis of nonalcoholic fatty liver disease, is an invasive procedure and its results will not influence treatment in most cases but will provide prognostic information. Assessment of fibrosis by composite scores, specific laboratory parameters and transient elastography might reduce the number of nonalcoholic fatty liver disease patients requiring liver biopsy. Dieting and physical training reinforced by behavioural therapy are associated with improved nonalcoholic fatty liver disease. Diabetes and the metabolic syndrome should be ruled out at timed intervals in nonalcoholic fatty liver disease. Nonalcoholic steatohepatitis patients should undergo periodic evaluation of cardiovascular risk and of advancement of their liver disease; those with nonalcoholic steatohepatitis-cirrhosis should be evaluated for early diagnosis of hepatocellular carcinoma.

Impact of pegylated interferon and ribavirin on morbidity and mortality in patients with chronic hepatitis C and normal aminotransferases in France

Clinicians continue to raise questions concerning the necessity of treating chronic hepatitis C virus (HCV)-infected patients with normal alanine aminotransferase (N-ALT), in light of their slower progression to cirrhosis than patients with elevated alanine aminotraferase (E-ALT). This study was undertaken to predict the impact of pegylated interferon (IFN) and ribavirin on HCV-related morbidity and mortality in patients with N-ALT. A previous Markov model was adapted to separately simulate patients with N-ALT (30%) and those with E-ALT (70%). The model estimates fibrosis progression rates according to age, sex, and whether ALT levels are normal or elevated, assuming that patients with E-ALT have a 2.6 times higher progression than those with N-ALT. It takes into account improvement in HCV screening and treatment and competitive mortality. We assumed that N-ALT patients were treated 80% less frequently between 2002 and 2004 and 70% less frequently from 2005 on, as obtained in real life from three multicentric cohorts (Hepatys, Adequation, Persee). Antiviral treatment of HCV-infected populations might reduce 2008-2025 HCV-related morbidity and mortality by 34,200 cases of cirrhosis (36%, 33,000-35,000), 22,400 complications (28%, 21,000-23,000) and 17,500 deaths (25%, 17,000-18,000), including 3000 cases of cirrhosis (22%, 2000-5000), 1200 complications (15%, 1000-1700), and 1000 deaths (14%, 900-1300) in the N-ALT population, despite a probability of receiving treatment that is three to five times less in this population. If N-ALT patients are treated at the same proportions as those with E-ALT, morbidity and mortality could be further reduced by 1400 cases of cirrhosis (13%, 1200-2200), 600 complications (9%, 600-1000), and 500 deaths (9%, 500-800).

CONCLUSION

Treatment of N-ALT patients would decrease HCV morbidity and mortality. These patients should be considered candidates for treatment just as others are.

Treatment of hepatitis C virus carriers with persistently normal alanine aminotransferase levels with peginterferon alpha-2a and ribavirin: a multicentric study

BACKGROUND/AIMS

To evaluate, in clinical practice, the efficacy and safety of combined antiviral treatment in hepatitis C virus (HCV) carriers with normal alanine aminotransferase (ALT) levels.

METHODS

Eighty-eight HCV carriers with persistently normal ALT levels were enrolled. All patients received peginterferon (PEG-IFN) alpha-2a 180 microg once weekly plus ribavirin (RBV) 800 mg/day for 24 weeks (HCV-2 and -3) or 1000-1200 mg/day for 48 weeks (HCV-1).

RESULTS

Rapid virological response (RVR) was seen in 66/88 patients (75%): 19/32 HCV-1 (59%), 40/46 HCV-2 (87%) and 7/10 HCV-3 patients. Younger patients, leaner subjects and patients with non-1 genotype or lower baseline HCV RNA levels were more likely to achieve an RVR. Sustained virological response (SVR) was seen in 69/88 patients (78%): 20/32 HCV-1 patients (62%), 41/46 HCV-2 patients (89%) and 8/10 (80%) HCV-3 patients. The overall SVR rate was 88% in patients with RVR (58/66) and 50% in those without RVR.

CONCLUSIONS

The combination of PEG-IFN alpha-2a and RBV produces, in patients with normal ALT, virological response rates that are comparable or even higher than those obtained in patients with elevated ALT levels. Thus, we suggest that in selected cases immediate therapy might be preferred to a 'wait-and-see' policy.

The impact of hepatic steatosis on the natural history of chronic hepatitis C infection

Since patients with hepatitis C virus (HCV) often have hepatic steatosis, this retrospective analysis aimed to assess whether steatosis influences fibrosis progression. We studied 112 HCV RNA positive subjects (median age 44, IQR 39-51 years), who had two liver biopsies performed (median biopsy interval 50, 34-74 months). Fibrosis was staged using the Ishak method and steatosis by the Kleiner system (<5% steatosis = S0, 5-33% = S1, 33-66% = S2, and >66% = S3). The subjects were untreated because they had mild fibrosis (n = 59), declined therapy (n = 48), or had co-existing disease precluding treatment (n = 5). On first liver biopsy, 60 (54%) had S0, 34 (30%) had S1, 12 (11%) had S2, and 6 (5%) had S3. Steatosis was associated with genotype 3, odds ratio 4.8 (95% CI 1.3-16.7, P = 0.02). Twenty-three patients (21%) had disease progression on the second biopsy, defined as an increase in Ishak score by > or =1 stage. On univariate analysis, fibrosis progression was associated with older age (P = 0.004), higher AST (P = 0.04), and steatosis (P = 0.005) but on multivariate analysis, only baseline steatosis was significant, odds ratio 14.3 (2.1-111.1, P = 0.006). Kaplan-Meier analysis demonstrated that steatosis impacted on time to progression to both significant fibrosis (Ishak > or =F3) and cirrhosis (Ishak F5-6) (P = 0.001 and P = 0.049, respectively). The finding that steatosis was significantly associated with fibrosis progression indicates that, independent of baseline fibrosis stage, patients should be considered for anti-viral treatment if steatosis is present. Furthermore, strategies to reduce steatosis may have a beneficial effect on fibrosis progression and, therefore, patient outcome.

Antiviral treatment for hepatitis C virus infection: effectiveness at general population level in a highly endemic area

BACKGROUND

Peginterferon plus ribavirin treatment induced a sustained virological response in >50% of HCV-RNA-positive individuals enrolled in published clinical trials.

AIM

To determine anti-HCV treatment effectiveness at a general population level.

PATIENTS AND METHODS

In 2002, a 1:5 random sample of >11 years old inhabitants of a small Italian town (Cittanova) was invited for HCV screening. HCV-RNA-positive individuals were evaluated for antiviral treatment.

RESULTS

1645 of 1924 invited individuals (85.5%) participated in the screening. 84 HCV-RNA-positive individuals were detected: median age was 65 years (range: 32-87); 67% was infected with genotype 1 or 4. Antiviral treatment was judged unnecessary for 43 (51.2%), due to persistently normal alanine aminotransferases, mild disease at liver biopsy or age >70 years without cirrhosis. Twenty-eight of the remaining 41 patients (68.3%) were ineligible for treatment, because of medical/psychiatric contraindications (42.9%), alcohol/drug abuse (17.9%), decompensated cirrhosis/hepatocellular carcinoma (17.9%), not attending official appointments (10.7%), previous intolerance/non-response to interferon plus ribavirin (10.7%). 5 of 13 eligible patients (38.5%) did not receive treatment (4 refused and 1 accidental death). 3 of 8 treated patients (37.5%) reached a sustained virological response.

CONCLUSIONS

Although efficacy of anti-HCV therapy improved in recent years, we found that low eligibility to treatment still limited its effectiveness at general population level in a highly endemic town.

Expression, purification, and initial characterization of human alanine aminotransferase (ALT) isoenzyme 1 and 2 in High-five insect cells

Alanine aminotransferase (ALT) is a key enzyme for gluconeogenesis as well as a widely used serum marker for liver injury. We have identified two ALT isoenzymes, ALT1 and ALT2, which are encoded by separate genes. In this study, we described the expression, purification and initial characterization of human ALT1 and ALT2 proteins in High-five insect cells. Human ALT1 and ALT2 were expressed as His-tagged fusion proteins by recombinant baculovirus in insect cells and purified into homogeneity in one step by using immobilized Ni2+-affinity chromatography. Tag-free ALT1 and ALT2 were obtained by cleavage of enterokinase digestion and used for initial characterization of the enzymes. The specific ALT activity of purified fusion or His-tag-removed ALT1 was about 15-fold higher than that of ALT2 and their enzymatic activities decreased quickly at 37 degrees C and -20 degrees C, but were well preserved at -80 degrees C. Nevertheless, the ALT1 and ALT2 activities remained stable in a buffer containing 25% glycerol. The pH profile was similar between hALT1 and hALT2 in that both enzymes remained fully active between pH 6.5 and 8.0. The purified ALT recombinant proteins can not only be used as a reference protein standard for the ALT assay in clinical chemistry, but also will be useful for understanding the biochemical and biological significance of the isoenzymes and for developing ALT isoform-specific assays for clinical or preclinical diagnostic use.