Association between vitamin D and hepatitis C virus infection: A meta-analysis

AIM:To evaluate the association between 25-hydroxyvitamin D[25(OH)D]and sustained virological response(SVR)in hepatitis C virus(HCV)infected individuals.METHODS:Relevant studies were identified by systematically searching MEDLINE databases up to March2012 and abstracts of the European and American Congress of Hepatology conducted in 2011.Studies must provide information on SVR and the levels of 25(OH)D3and/or 25(OH)D2[henceforth referred to as 25(OH)D]in sera samples from HCV infected individuals.The inclusion criteria were:clinical studies that included HCV infected patients aged older than 18 years regardless of HCV genotype or ethnic group;provided information on SVR rates;and were reported in the English languageas full papers.Due to the heterogeneity of studies in categorizing serum vitamin D levels,a cut-off value of30 ng/mL of serum 25(OH)D was used.Heterogeneity was assessed using I2statistics.The summary odds ratios with their corresponding 95%CI were calculated based on a random-effects model.RESULTS:Overall,11 studies(8 observational and 3interventional)involving 1575 individuals were included and 1117 HCV infected individuals(71%)showed low vitamin D levels.Most of the studies included monoinfected HCV individuals with the mean age ranging from 38 to 56 years.Four studies were conducted in human immunodeficiency virus/HCV infected individuals.Regarding vitamin D measurement,most of the studies employed radioimmunoassays(n=5)followed by chemiluminescence(n=4)and just one study employed high performance/pressure liquid chromatography(HPLC).Basal vitamin D levels varied from 17 to43 ng/mL in the studies selected,and most of the HCV infected individuals had genotype 1(1068/1575)with mean viral load varying from log 4.5-5.9 UI/mL.With regard to HCV treatment,most of the studies(n=8)included HCV individuals without previous treatment,where the pooled SVR rate was 46.4%.High rates of SVR were observed in HCV individuals with vitamin D levels above 30 ng/mL(OR=1.57;95%CI:1.12-2.2)and those supplemented with     

Enhanced antiviral effect in cell culture of type 1 interferon and ribozymes targeting HCV RNA

We have recently shown that the replication of an HCV-poliovirus (PV) chimera that is dependent upon the hepatitis C virus (HCV) 5' untranslated region (UTR) can be inhibited by treatment with ribozymes targeting HCV RNA. To determine the antiviral effects of anti-HCV ribozyme treatment in combination with type 1 interferon (IFN), we analysed the replication of this HCV-PV chimera in HeLa cells treated with anti-HCV ribozyme and/or IFN-α2a, IFN-α2b, or consensus IFN. The anti-HCV ribozyme, or any of the IFNs alone have significant inhibitory effects on HCV-PV replication compared to control treatment (≥ 85%, P  < 0.01). The maximal inhibition due to IFN treatment (94%, P  < 0.01) was achieved with ≥ 50 U/ml for either IFN-α2a or IFN-α2b compared to control treatment. A similar level of inhibition in viral replication could be achieved with a 5-fold lower dose of IFN if ribozyme targeting the HCV 5' UTR was given in combination. For consensus IFN, the dose could be reduced by > 12.5-fold if ribozyme targeting the HCV 5' UTR was given in combination. Conversely, the dose of ribozyme could be reduced 3-fold if given in combination with any of the IFN preparations. Moreover, treatment with low doses (1–25 U/mL) of IFN-α2a, IFN-α2b, or consensus IFN in combination with anti-HCV ribozyme resulted in > 98% inhibition of HCV-PV replication compared to control treatment ( P  < 0.01). These results demonstrate that IFN and ribozyme each have a beneficial antiviral effect that is augmented when given in combination.     

Intention-to-treat analysis of liver transplantation for hepatocellular carcinoma: living versus deceased donor transplantation

Vitamin D supplementation was reported to improve the probability of achieving a sustained virological response when combined with antiviral treatment against hepatitis C virus (HCV). Our aim was to determine the in vitro potential of vitamin D to inhibit HCV infectious virus production and explore the mechanism(s) of inhibition. Here we show that vitamin D(3) remarkably inhibits HCV production in Huh7.5 hepatoma cells. These cells express CYP27B1, the gene encoding for the enzyme responsible for the synthesis of the vitamin D hormonally active metabolite, calcitriol. Treatment with vitamin D(3) resulted in calcitriol production and induction of calcitriol target gene CYP24A1, indicating that these cells contain the full machinery for vitamin D metabolism and activity. Notably, treatment with calcitriol resulted in HCV inhibition. Collectively, these findings suggest that vitamin D(3) has an antiviral activity which is mediated by its active metabolite. This antiviral activity involves the induction of the interferon signaling pathway, resulting in expression of interferon-β and the interferon-stimulated gene, MxA. Intriguingly, HCV infection increased calcitriol production by inhibiting CYP24A1 induction, the enzyme responsible for the first step in calcitriol catabolism. Importantly, the combination of vitamin D(3) or calcitriol and interferon-α synergistically inhibited viral production. CONCLUSION: This study demonstrates for the first time a direct antiviral effect of vitamin D in an in vitro infectious virus production system. It proposes an interplay between the hepatic vitamin D endocrine system and HCV, suggesting that vitamin D has a role as a natural antiviral mediator. Importantly, our study implies that vitamin D might have an interferon-sparing effect, thus improving antiviral treatment of HCV-infected patients.     

Testing for hepatitis C virus sequences in peripheral blood mononuclear cells of patients with chronic hepatitis C in the absence of serum hepatitis C virus RNA

Hepatitis C virus (HCV) is able to replicate in peripheral blood mononuclear cells (PBMC) of HCV-infected patients. Few data are available on PBMC testing for HCV RNA in serum HCV RNA negative patients, positive for anti-HCV and with histological evidence of chronic hepatitis. Twenty such patients were studied; of these, 11 were tested during interferon α (IFN) treatment, at the time of serum HCV RNA clearance and ALT normalisation: only one was found to be positive for HCV sequences in PBMC. Within 3 months of IFN withdrawal all 11 patients relapsed with high ALT and recurrence of serum HCV RNA. Of nine serum HCV RNA negative patients with chronic hepatitis C who were not receiving IFN when tested (four untreated patients and five patients who had already completed IFN schedule), PBMC HCV RNA was detected in four. Evidence of active HCV replication (presence of the minus strand genome) in PBMC was also observed in two cases. Thus, five of the 20 patients without detectable serum HCV RNA turned out to be carriers of HCV sequences in PBMC. These data indicate that: 1. PBMC are an extrahepatic replication site of HCV; this is true also in the absence of serum HCV RNA; 2. the role of PBMC as a “viral reservoir” after IFN-induced serum HCV RNA clearance is questioned; 3. the absence of both serum and PBMC HCV RNA in patients under IFN is not predictive of sustained viral loss; 4. testing for PBMC viral sequences might enhance the chances of detecting HCV infection.     

Hepatitis C virus (HCV) relapses after anti-HCV therapy are more frequent in HIV-infected patients

The response to standard or pegylated interferon (IFN) plus ribavirin (RBV) seems to be lower in hepatitis C virus (HCV)/HIV-coinfected subjects than in HCV-monoinfected patients. Thus, the principles guiding anti-HCV therapy in HIV-negative patients may not apply in the setting of HIV infection. We examined the rate of HCV relapse in 58 HCV/HIV-coinfected subjects who showed undetectable HCV-RNA (<600 IU/ml) at the end of anti-HCV combination therapy. Overall, 19 (32.8%) patients relapsed after discontinuing treatment, a rate significantly higher than that seen in HIV negatives, which is in the range of 15-20%. There were no significant differences between HCV genotypes (33.3% for HCV genotypes 2-3 versus 31.8% for HCV genotypes 1-4) and/or the use of either standard or pegylated IFN (37% versus 29%, respectively). Thus, extended periods of anti-HCV therapy might reduce HCV relapses in HIV-coinfected patients initially responding to therapy.     

Disruption of hepatitis C virus RNA replication through inhibition of host protein geranylgeranylation

Hepatitis C virus (HCV) RNA replication depends on viral protein association with intracellular membranes, but the influence of membrane composition on viral replication is unclear. We report that HCV RNA replication and assembly of the viral replication complex require geranylgeranylation of one or more host proteins. In cultured hepatoma cells, HCV RNA replication was disrupted by treatment with lovastatin, an inhibitor of 3-hydroxy-3-methyglutaryl CoA reductase, or with an inhibitor of protein geranylgeranyl transferase I, each of which induced the dissolution of the HCV replication complex. Viral replication was not affected by treatment of cells with an inhibitor of farnesyl transferase. When added to lovastatin-treated cells, geranylgeraniol, but not farnesol, restored replication complex assembly and viral replication. Inasmuch as the HCV genome does not encode a canonical geranylgeranylated protein, the data suggest the involvement of a geranylgeranylated host protein in HCV replication. Inhibition of its geranylgeranylation affords a therapeutic strategy for treatment of HCV infection.     

Kinetics of the hepatitis C virus during interferon therapy as a marker of therapeutic response

BACKGROUND: The viral load and subtype of hepatitis C virus (HCV) are predictors of the efficacy of interferon (IFN) therapy. The kinetics of HCV during IFN therapy have been described recently, suggesting that HCV infection is highly dynamic. These observations have raised the issue as to whether early monitoring of the viral load can help guide IFN therapy. METHODS: We measured HCV-RNA levels at 0, 24 and 48 h after the start of IFN-alpha treatment (10 MU daily for 2 weeks and then three times weekly for 22 weeks) or IFN-beta treatment (6 MU daily for 6 weeks). Then we analyzed the relationship between HCV kinetics and therapeutic response using stepwise multivariate logistic regression analysis. RESULTS: The exponential decay slope of the viral load during the first 24 h, not the first 48 h or the next 24 h, was a predictor of viral eradication at 6 months after completion of the treatment (sustained response; P = 0.0023). This decay slope was not affected by the HCV serotype or the type of IFN used. Initial viral load and HCV serotype were also predictors, as reported previously (P < 0.0001 and P = 0.0347, respectively). We also proposed a model using a prognostic index that predicted a sustained response with more than 80% sensitivity, specificity and efficacy in an independent and external group of patients. CONCLUSION: This study demonstrated that the exponential decay slope of the viral load during the first 24 h was an important predictor of the response to IFN therapy as well as the initial viral load and HCV serotype. The model may also be useful for the clinical management of IFN therapy.     

Hypovitaminosis D and its relation to demographic and laboratory data among hepatitis C patients

Background. The relationship between 25-hydroxyvitamin D [25(OH)D] serum levels and response to antiviral therapy and laboratory data in HCV infection remains unclear. The aim of this study was to determine pre-treatment 25(OH)D serum level among HCV infected individuals and to evaluate the association between vitamin D status, virological response, and laboratory data.Material and methods. Baseline serum 25(OH)D levels were measured in 237 chronic HCV infected patients (139 female, age 53.7 ± 11.2 years) using chemiluminescence immunoassay. Correlations between serum 25(OH)D levels, virological and laboratory data regarding HCV infection as well as sustained virological response (SVR) to antiviral therapy were evaluated.Results. Mean serum values of 25(OH)D was 26.2 ± 12 ng/mL and prevalence of vitamin D deficiency (< 30 ng/mL) was 66.2%. Advanced age (> 55 years), high mean values of LDL, total cholesterol, HDL and low mean values of alkaline phosphatase and hemoglobin were statistically associated to vitamin D deficiency. Antiviral treatment was underwent by 133 HCV patients and 44.3% of them achieved SVR. Most of individuals that presented SVR also presented 25(OH)D level higher than 30ng/mL (55.9%). SVR was associated to low mean values of LDL, total cholesterol and platelets; high mean values of ALT, AST and low fibrosis grade. Conclusions: In conclusion, low vitamin D levels were observed among HCV infected patients and was associated to laboratory findings, however baseline 25(OH)D level is not independently associated with SVR.     

Antiviral therapy: chronic hepatitis C

Summary.  The combination of pegylated interferon (IFN) with ribavirin is the standard of care for chronic hepatitis C. Response rates range from 50 to 90% for genotype 1 and 2/3 which also differ in the duration of treatment (48 vs 24 weeks, respectively). Therapy if given with weight-based dosing may be shortened from 24 to 12, 14 or 16 weeks (genotypes 2 and 3), and from 48 to 24 weeks (genotype 1) in case of hepatitis C virus (HCV) clearance at week 4, without reducing sustained virologic response (SVR). Conversely, prolonging treatment for 72 weeks in those with only a decrease of viral load at week 4, i.e. "slow responders" increases SVR rates by preventing relapse. In spite of such progress, over half of patients are relapsers or nonresponders. If the previous treatment was suboptimal, retreatment with higher doses or longer duration may be beneficial unless an individual was a 'null responder' previously. New promising anti-HCV molecules (antiproteases and antipolymerases), some with potent antiviral activity, are in phase II trials but appear to require the addition of IFN and ribavirin to maintain viral suppression. Other immunomodulatory agents such as new IFN or therapeutic vaccines and alternatives to ribavirin are also under development. Future regimens should improve efficacy and provide shorter and better-tolerated combination therapy.     

Effect of vitamin D supplementation on pegylated interferon/ribavirin therapy for chronic hepatitis C genotype 1b: a randomized controlled trial

Chronic HCV–infected patients tend to have vitamin D deficiency, suggesting that vitamin D supplementation may enhance the efficacy of treatment with pegylated interferon (PEG‐IFN) and ribavirin (RBV). We therefore assessed the effects of vitamin D supplementation on viral response to PEG‐IFN/RBV. Eighty‐four patients with HCV genotype 1b were randomized, 42 to oral vitamin D supplementation (1000 IU/day) and 42 to nonsupplementation (control), from week 8 to the end of PEG‐IFN/RBV therapy. The primary end point was undetectable HCV RNA at week 24 (viral response [VR]). VR rate at week 24 was significantly higher in the vitamin D than in the control group (78.6% vs 54.8% P = 0.037). Adverse events were similar in both groups. When patients were subdivided by IL28B SNP rs8099917 genotype, those with the TT genotype group showed a significantly higher VR rate at week 24 with than without vitamin D supplementation (86.2% vs 63.3% vs P = 0.044). Although patients with the TG/GG genotype, who were relatively resistant to PEG‐IFN treatment, had similar VR rates at week 24 with and without vitamin D supplementation, the decline in viral load from week 8 to week 24 was significantly greater with than without vitamin D supplementation. Multivariate analysis showed that rs8099917 genotype and vitamin D supplementation contributed significantly to VR at week 24. SVR rates were similar in the vitamin D and control groups [64.3% (27/42) vs 50% (21/42), P = 0.19]. Vitamin D supplementation may enhance the effects of PEG‐IFN/RBV in HCV genotype 1b–infected patients.     

Vitamin D in addition to peg-interferon-alpha/ribavirin in chronic hepatitis C virus infection: ANRS-HC25-VITAVIC study

AIM: To investigate if correction of hypovitaminosis D before initiation of Peg-interferon-alpha/ribavirin(Peg IFN/RBV) therapy could improve the efficacy of Peg IFN/RBV in previously null-responder patients with chronic genotype 1 or 4 hepatitis C virus(HCV) infection.METHODS:Genotype 1 or 4 HCV-infected patients with null response to previous Peg IFN/RBV treatment and with hypovitaminosis D(30 ng/m L)prospectively received cholecalciferol 100000 IU per week for 4 wk[from week-4(W-4)to W0],followed by 100000 IUper month in combination with Peg IFN/RBV for 12 mo(from W0 to W48).The primary outcome was the rate of early virological response defined by an HCV RNA12 IU/m L after 12 wk Peg IFN/RBV treatment.RESULTS:A total of 32 patients were included,19(59%)and 13(41%)patients were HCV genotype1 and 4,respectively.The median baseline vitamin D level was 15 ng/m L(range:7-28).In modified intention-to-treat analysis,29 patients who received at least one dose of Peg IFN/RBV were included in the analysis.All patients except one normalized their vitamin D serum levels.The rate of early virologic response was 0/29(0%).The rate of HCV RNA12IU/m L after 24 wk of Peg IFN/RBV was 1/27(4%).The safety profile was favorable.CONCLUSION:Addition of vitamin D to Peg IFN/RBV does not improve the rate of early virologic response in previously null-responders with chronic genotype 1or 4 HCV infection.     

Recently acquired hepatitis C virus infection among people living with human immunodeficiency virus at a university hospital in Taiwan

BACKGROUNDLittle is known about the engagement in hepatitis C virus (HCV) care and completion of HCV treatment in people living with human immunodeficiency virus (HIV) (PLWH) who have HCV coinfection in the Asia-Pacific region. Examining the HCV care cascade can identify barriers to the completion of HCV treatment and facilitate achievement of HCV micro-elimination in PLWH.AIMTo investigate the care cascade of incident HCV infections among PLWH in Taiwan.METHODSPLWH with incident HCV infections, defined as HCV seroconversion, were retrospectively identified by sequential anti-HCV testing of all archived blood samples at National Taiwan University Hospital between 2011 and 2018. All PLWH with incident HCV infections were followed until December 31, 2019. The care cascade of HCV examined included all incident HCV-infected patients, the percentages of anti-HCV antibodies detected by HIV-treating physicians in clinical care, plasma HCV RNA load tested, HCV RNA positivity diagnosed, referral to treatment assessment made, anti-HCV treatment initiated, and sustained virologic response achieved. Those who had HCV seroconversion during the interferon (IFN) era (2011–2016) and the direct-acting antiviral (DAA) era (2017–2018) were analyzed separately. The duration of HCV viremia—from the date of seroconversion to viral clearance by treatments or until the end of observation—and the incidence of sexually transmitted infections (STIs) during the HCV viremic period were estimated.RESULTSDuring the study period, 287 of 3495 (8.2%) PLWH (92.3% being men who have sex with men) who were HCV-seronegative at baseline developed HCV seroconversion by retrospective testing of all archived blood samples. Of the 287 incident HCV infections, 277 (96.5%) had anti-HCV antibodies detected by HIV-treating physicians, 270 (94.1%) had plasma HCV RNA determined and 251 (87.5%) tested positive for HCV RNA. Of those with HCV viremia, 226 (78.7%) were referred to treatment assessment, 215 (74.9%) initiated anti-HCV treatment, and 202 (70.4%) achieved viral clearance. Compared with that in the IFN era, the median interval from HCV seroconversion by retrospective testing to detection of HCV seropositivity by HIV-treating physicians was significantly shorter in the DAA era {179 d [interquartile range (IQR) 87-434] vs 92 d (IQR 57-173); P < 0.001}. The incidence rate of STIs in the DAA vs the IFN era was 50.5 per 100 person-years of follow-up (PYFU) and 38.5 per 100 PYFU, respectively, with an incidence rate ratio of 1.31 (95% confidence interval 0.96-1.77), while the duration of HCV viremia was 380 d (IQR 274-554) and 735 d (IQR 391-1447) (P < 0.001), respectively.CONCLUSIONWhile anti-HCV therapies are effective in achieving viral clearance, our study suggests more efforts are needed to expedite the linkage of PLWH diagnosed with incident HCV infections to HCV treatment.     

Current therapy for hepatitis C or D or immunodeficiency virus concurrent infection with chronic hepatitis B

Concurrent hepatitis C virus (HCV), hepatitis delta virus (HDV), or human immunodeficiency virus (HIV) infection with chronic hepatitis B virus (HBV) appears to increase the risk of progressive liver disease including liver cirrhosis and hepatocellular carcinoma. There is a 10% prevalence of HCV infection in chronic HBV or HDV infection. Serological evidence of previous exposure to HBV is found in more than 80% of HIV-positive patients in the high risk group. Notably, the most recently acquired virus tends to suppress the pre-existing virus. In chronic HBV infection acquired perinatally or in early childhood, usually HCV is dominant and may suppress or even displace HBV and HDV. Less frequently, HBV or HDV suppresses HCV. It is generally agreed that the dominant virus should be identified in order to make appropriate treatment decisions. Studies with standard interferon (IFN) to treat patients with HCV dominantly dual HBV/HCV infection have showed only limited virological response. But high dose of IFN has been demonstrated with better response rate. Combined ribavirin with standard or pegylated IFN therapy could achieve a sustained HCV clearance rate comparable with those infected with HCV alone. On the contrary, patients with HBV dominantly dual viral infection might indicate more appropriate addition of lamivudine to IFN than ribavirin. Additionally, patients with concurrent infection of HBV and HDV, IFN seems to be the only effective agent. However, the efficacy of IFN is related to the dose. High dose of IFN [9 MU tiw (thrice per week)] and longer treatment duration (at least 2 years) have been shown to achieve adequate virological response. In patients with concurrently infected HBV and HIV, anti-HBV therapy should be considered for all patients with evidence of liver disease, irrespective of the CD4 cell count. In patients not requiring antiretroviral therapy, HBV therapy should be preferentially based on IFN, adefovir, or telbivudine. In contrast, in patients with CD4 cell counts <350 cells/μl or those already on antiretroviral therapy, agents with double anti-HBV and anti-HIV activity are preferred. At present, the evidence of therapeutic efficacy is not sufficient to make a recommendation in treating patients with dual HBV/HCV or HBV/HDV or HBV/HIV infection. Further studies of the well-designed, larger scale are needed to elucidate the role of different regimens or combination in the treatment of dual viral infection.     

Specifically targeted antiviral therapy for hepatitis C virus

Hepatitis C virus （HCV） infection affects 180 million people worldwide with the predominant prevalence being infection with genotype 1, followed by genotypes 2 and 3. Standard anti-HCV therapy currently aims to enhance natural immune responses to the virus, whereas new therapeutic concepts directly target HCV RNA and viral enzymes or influence host-virus interactions. Novel treatment options now in development are focused on inhibitors of HCV- specific enzymes, NS3 protease and NS5B polymerase. These agents acting in concert represent the concept of specifically targeted antiviral therapy for HCV （STAT-C）. STAT-C is an attractive strategy in which the main goal is to increase the effectiveness of antiviral responses across all genotypes, with shorter treatment duration and better tolerability. However, the emergence of resistant mutations that limit the use of these compounds in monotherapy complicates the regimens. Thus, a predictable scenario for HCV treatment in the future will be combinations of drugs with distinct mechanisms of action. For now, it seems that interferon will remain a fundamental component of any new anti-HCV therapeutic regimens in the near future; therefore, there is pressure to develop forms of interferon that are more effective, less toxic, and more convenient than pegylated interferon.     

Suppression of hepatitis C virus by the flavonoid quercetin is mediated by inhibition of NS3 protease activity

Phytochemicals exert antiviral activity and may play a potential therapeutic role in hepatitis C virus (HCV) infection. In this work, we aimed to isolate NS3 inhibitors from traditional Indian medicinal plants that were found, in our earlier study, to inhibit HCV NS3 protease activity and to evaluate their potential to inhibit HCV replication. A potent inhibitory effect of NS3 catalytic activity was obtained with Embelia ribes plant extracts. Quercetin, a ubiquitous plant flavonoid, was identified as the active substance in the fractioned extract. It was found to inhibit NS3 activity in a specific dose-dependent manner in an in vitro catalysis assay. Quercetin inhibited HCV RNA replication as analysed in the subgenomic HCV RNA replicon system. It also inhibited HCV infectious virus production in the HCV infectious cell culture system (HCVcc), as analysed by the focus-forming unit reduction assay and HCV RNA real-time PCR. The inhibitory effect of quercetin was also obtained when using a model system in which NS3 engineered substrates were introduced in NS3-expressing cells, providing evidence that inhibition in vivo could be directed to the NS3 and do not involve other HCV proteins. Our work demonstrates that quercetin has a direct inhibitory effect on the HCV NS3 protease. These results point to the potential of quercetin as a natural nontoxic anti-HCV agent reducing viral production by inhibiting both NS3 and heat shock proteins essential for HCV replication.     

Vitamin D, sunlight and longevity

Humans acquire vitamin D through skin photosynthesis and digestive intake. Two hydroxylations are needed to obtain the bioactive compound, the first produces 25-hydroxyvitamin D [25(OH)D], and the second 1,25-dihydroxyvitamin D [1,25(OH)2D]. There is no consensus regarding the appropriate cut-off level to define the normal serum 25(OH)D range. Experimental, epidemiological and clinical studies have related low vitamin D status with longevity. Although some results are controversial, low serum 25(OH)D levels have been linked to all-cause, cardiovascular, cancer and infectious related mortality. Throughout life span a significant proportion of human beings display insufficient (20-30 ng/mL) or deficient (<20 ng/mL) serum 25(OH)D levels. Appropriate lifestyle changes, such as regular short exposures to sunlight (15 min a day), and an adequate diet that includes vitamin D rich components, are not always easily accomplished. Studies relating to vitamin D supplementation have methodological limitations or are based on relatively low doses. Therefore, dosages used for vitamin D supplementation should be higher than those traditionally suggested. In this sense, there is an urgent need for prospective controlled studies using high daily vitamin D doses (2,000 IU or higher) including cardiovascular, cancer, infectious and other endpoints. Relationship between vitamin D and health outcomes is not linear, and there are probably various optimal vitamin D levels influencing different endpoints.     

Antiviral therapy for chronic hepatitis C: past, present, and future

Antiviral therapy for chronic hepatitis C has dramatically advanced since the discovery of the hepatitis C virus (HCV) in 1989 and the introduction of interferon (IFN) monotherapy in the early 1990s. The current standard therapy uses a combination of pegylated IFN and ribavirin. The duration of therapy and response to therapy are HCV genotype-specific. Genotype 1 patients require 48 weeks of the combination therapy for 50% successful viral elimination, while genotype 2 patients require 24 weeks of therapy for 80% or 90% viral elimination. Early viral kinetics after the initiation of therapy is a useful predictor of the sustained virologic response (SVR), which is formally determined at 24 weeks after completion of the treatment. For example, an early virologic response, which is determined by a 2-log reduction of HCV RNA or viral elimination at 12 weeks after the initiation of therapy, is a strong negative predictor of SVR in genotype 1 patients. In contrast, a rapid virologic response of HCV RNA-negative at 4 weeks after the initiation of therapy identifies genotype 2 “super-responders,” who may require a shorter period of therapy. Adherence to therapy is one of the most important factors for successful viral clearance. Hematopoietic growth factors such as epoetin and granulocyte-colony stimulating factor help reduce therapy-mediated cytopenia and improve patient compliance, thereby leading to better viral clearance. New types of anti-HCV agents such as HCV protease and polymerase inhibitors are needed for those patients that do not respond to combination therapy.     

Gastric autoimmune disorders in patients with chronic hepatitis C before,during and after interferon-alpha therapy

AIM: To explore the prevalence of autoimmune gastritis in chronic hepatitis C virus (HCV) patients and the influence of α-interferon (IFN) treatment on autoimmune gastritis.METHODS: We performed a prospective study on 189 patients with positive anti-HCV and viral RNA enrolled in a 12-month IFN protocol. We evaluated: a) the baseline prevalence of autoimmune gastritis, b) the impact of IFN treatment on development of biochemical signs of autoimmune gastritis (at 3, 6 and 22 months), c) the evolution after IFN withdrawal (22 months) in terms of anti-gastric-parietal-cell antibodies (APCA), gastrin, anti-thyroid, and anti-non-organ-specific antibodies. RESULTS: APCA positivity and 3-fold gastrin levels wered etected in 3 (1.6 %) and 9 (5 %) patients, respectively, at baseline, in 25 (13 %) and 31 (16 %) patients at the end of treatment (both P&lt;0.001, vs baseline), and in 7 (4 %) and 14 (7 %) patients 12 months after withdrawal (P=0.002 and P=0.01 respectively, vs baseline; P=not significant vs end of treabnent). The development of autoimmune gastritis was strictly associated with the presence of autoimmune thyroiditis (P =0.0001), no relationship was found with other markers of autoimmunity.CONCLUSION: In HCV patients, IFN frequently precipitates latent autoimmune gastritis, particularly in females. Following our 12-month protocol, the phenomenon generally regressed. Since APCA positivity and high gastrin levels are associated with the presence of antithyroid antibodies,development of autoimmune thyroiditis during IFN treatment may provide a surrogate preliminary indicator of possible autoimmune gastritis to limit the need for invasive examinations.     

Clinical trial results of peginterferons in combination with ribavirin

Of the large number of patients chronically infected with hepatitis C virus (HCV), only about one third have progressive liver disease, and will eventually develop cirrhosis and hepatocellular carcinoma. These are the patients for whom effective antiviral treatment is most needed. Therapy is currently recommended for patients with chronic hepatitis C who have abnormal alanine aminotransferase (ALT) levels, detectable hepatitis C virus ribonucleic acid (HCV RNA) in the blood, and significant necroinflammatory changes and/or fibrosis on liver biopsy. The current gold standard in terms of treatment efficacy is the combination of peginterferon (PEG-IFN) and ribavirin. The overall sustained virological response rate (SVR) with these regimens is 54 to 61% following 48 weeks of therapy. Patients with genotype 1 infection have a 42 to 51% likelihood of response to 48 weeks of therapy. Those with genotypes 2 or 3 infection will respond to 24 weeks of therapy in 78 to 82% of cases. These SVR rates are 5 to 10 percentage points higher in all patient groups than in those obtained with standard doses of interferon (IFN) and ribavirin. Retreatment of nonresponders to standard IFN monotherapy using PEG-IFN and ribavirin has achieved SVR rates of 34 to 40%. Retreatment of patients who relapsed after IFN monotherapy has resulted in an SVR rate of about 60%. A SVR after retreatment of relapsers and nonresponders with PEG-IFN and ribavirin is more likely in patients previously treated with IFN monotherapy, those with HCV genotypes 2 or 3, patients with low viral load (<2 million copies/mL), and individuals who had a significant decrease in HCV RNA levels during the initial treatment. The potential benefits of long-term anti-HCV suppressive therapy in nonresponders are currently under investigation.