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

The Role of Vitamin D and Vitamin D Binding Protein in Chronic Liver Diseases

Vitamin D (calciferol) is a fat-soluble vitamin that has a significant role in phospho-calcium metabolism, maintaining normal calcium levels and bone health development. The most important compounds of vitamin D are cholecalciferol (vitamin D3, or VD3) and ergocalciferol (vitamin D2, or VD2). Besides its major role in maintaining an adequate level of calcium and phosphate concentrations, vitamin D is involved in cell growth and differentiation and immune function. Recently, the association between vitamin D deficiency and the progression of fibrosis in chronic liver disease (CLD) was confirmed, given the hepatic activation process and high prevalence of vitamin D deficiency in these diseases. There are reports of vitamin D deficiency in CLD regardless of the etiology (chronic viral hepatitis, alcoholic cirrhosis, non-alcoholic fatty liver disease, primary biliary cirrhosis, or autoimmune hepatitis). Vitamin D binding protein (VDBP) is synthesized by the liver and has the role of binding and transporting vitamin D and its metabolites to the target organs. VDBP also plays an important role in inflammatory response secondary to tissue damage, being involved in the degradation of actin. As intense research during the last decades revealed the possible role of vitamin D in liver diseases, a deeper understanding of the vitamin D, vitamin D receptors (VDRs), and VDBP involvement in liver inflammation and fibrogenesis could represent the basis for the development of new strategies for diagnosis, prognosis, and treatment of liver diseases. This narrative review presents an overview of the evidence of the role of vitamin D and VDBP in CLD, both at the experimental and clinical levels.

Therapeutic Potential of Nutraceuticals and Dietary Supplements in the Prevention of Viral Diseases: A Review

Nowadays, despite enormous scientific advances, viral diseases remain the leading cause of morbidity worldwide, and their potential to spread is escalating, eventually turning into pandemics. Nutrition can play a major role in supporting the immune system of the body and for the optimal functioning of the cells of the immune system. A healthy diet encompassing vitamins, multi-nutrient supplements, functional foods, nutraceuticals, and probiotics can play a pivotal role in combating several viral invasions in addition to strengthening the immune system. This review provides comprehensive information on diet-based scientific recommendations, evidence, and worldwide case studies in light of the current pandemic and also with a particular focus on virus-induced respiratory tract infections. After reviewing the immune potential of nutraceuticals based on the lab studies and on human studies, it was concluded that bioactive compounds such as nutraceuticals, vitamins, and functional foods (honey, berries, etc.) with proven antiviral efficacy, in addition to pharmaceutical medication or alone as dietary supplements, can prove instrumental in treating a range of virus-induced infections in addition to strengthening the immune system. Milk proteins and peptides can also act as adjuvants for the design of more potent novel antiviral drugs.

Vitamin D supplementation for chronic liver diseases in adults

BACKGROUND

Vitamin D deficiency is often reported in people with chronic liver diseases. Improving vitamin D status could therefore be beneficial for people with chronic liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation in adults with chronic liver diseases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index-Science. We also searched ClinicalTrials.gov  and the World Health Organization International Clinical Trials Registry Platform. We scanned bibliographies of relevant publications and enquired experts and pharmaceutical companies as to additional trials. All searches were up to November 2020.

SELECTION CRITERIA

Randomised clinical trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults with chronic liver diseases. Vitamin D could have been administered as supplemental vitamin D (vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), 25-hydroxyvitamin D (calcidiol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 27 randomised clinical trials with 1979 adult participants. This review update added 12 trials with 945 participants. We assessed all trials as at high risk of bias. All trials had a parallel-group design. Eleven trials were conducted in high-income countries and 16 trials in middle-income countries. Ten trials included participants with chronic hepatitis C, five trials participants with liver cirrhosis, 11 trials participants with non-alcoholic fatty liver disease, and one trial liver transplant recipients. All of the included trials reported the baseline vitamin D status of participants. Participants in nine trials had baseline serum 25-hydroxyvitamin D levels at or above vitamin D adequacy (20 ng/mL), whilst participants in the remaining 18 trials were vitamin D insufficient (less than 20 ng/mL). Twenty-four trials administered vitamin D orally, two trials intramuscularly, and one trial intramuscularly and orally. In all 27 trials, the mean duration of vitamin D supplementation was 6 months, and the mean follow-up of participants from randomisation was 7 months. Twenty trials (1592 participants; 44% women; mean age 48 years) tested vitamin D₃ (cholecalciferol); three trials (156 participants; 28% women; mean age 54 years) tested vitamin D₂; four trials (291 participants; 60% women; mean age 52 years) tested 1,25-dihydroxyvitamin D; and one trial (18 participants; 0% women; mean age 52 years) tested 25-hydroxyvitamin D. One trial did not report the form of vitamin D. Twelve trials used a placebo, whilst the other 15 trials used no intervention in the control group. Fourteen trials appeared to be free of vested interest. Eleven trials did not provide any information on clinical trial support or sponsorship. Two trials were funded by industry. We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on all-cause mortality (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.51 to 1.45; 27 trials; 1979 participants). The mean follow-up was 7 months (range 1 to 18 months). We are very uncertain regarding the effect of vitamin D versus placebo or no intervention on liver-related mortality (RR 1.62, 95% CI 0.08 to 34.66; 1 trial; 18 participants) (follow-up: 12 months); serious adverse events such as hypercalcaemia (RR 5.00, 95% CI 0.25 to 100.8; 1 trial; 76 participants); myocardial infarction (RR 0.75, 95% CI 0.08 to 6.81; 2 trials; 86 participants); thyroiditis (RR 0.33, 95% CI 0.01 to 7.91; 1 trial; 68 participants); circular haemorrhoidal prolapse (RR 3.00, 95% CI 0.14 to 65.9; 1 trial; 20 participants); bronchopneumonia (RR 0.33, 95% CI 0.02 to 7.32; 1 trial 20 participants); and non-serious adverse events. The certainty of evidence for all outcomes is very low. We found no data on liver-related morbidity such as gastrointestinal bleeding, hepatic encephalopathy, hepatorenal syndrome, ascites, or liver cancer. There were also no data on health-related quality of life. The evidence is also very uncertain regarding the effect of vitamin D versus placebo or no intervention on rapid, early, and sustained virological response in people with chronic hepatitis C.

AUTHORS' CONCLUSIONS

Given the high risk of bias and insufficient power of the included trials and the very low certainty of the available evidence, vitamin D supplementation versus placebo or no intervention may increase or reduce all-cause mortality, liver-related mortality, serious adverse events, or non-serious adverse events in adults with chronic liver diseases. There is a lack of data on liver-related morbidity and health-related quality of life. Further evidence on clinically important outcomes analysed in this review is needed.

Inhibition of hepatitis C virus by vitamin D

Until the development of direct-acting antivirals (DAAs), interferon (IFN)-based therapy had been the primary treatment strategy for patients with chronic hepatitis C, even though this therapy has a therapeutic limitations and considerable side effects. Therefore, many efforts have been made to improve the efficacy of treatment. Several clinical studies have clearly shown that supplementation with vitamin D of IFN-based therapy improves treatment efficacy. To clarify the molecular mechanisms of the effect of vitamin D on IFN-based therapy, several researchers have performed basic research with cell culture models of hepatitis C virus (HCV). Consequently, two vitamin D₃ metabolites, 25-hydroxyvitamin D₃ (25-(OH)D₃) and 1α,25-dihydroxyvitamin D₃ (1α,25-(OH)₂D₃), have been suggested to have anti-HCV effects. 25-(OH)D₃ inhibits HCV production by suppressing infectious virus assembly through reducing apolipoprotein expression, while 1α,25-(OH)₂D₃ inhibits HCV production by modulating IFN signaling and/or inducing various host factors associated with the inhibition of viral genome replication. In addition, an antimicrobial peptide, LL-37, which is known to be partly regulated by vitamin D, was also reported to exhibit an anti-HCV effect by disrupting infectious viral particles directly. In conclusion, vitamin D₃ supplementation improves the response rate of IFN-based therapy via the direct and/or indirect anti-HCV effects of vitamin D₃ metabolites.

Vitamin D, zinc and glutamine: Synergistic action with OncoTherad immunomodulator in interferon signaling and COVID‑19 (Review)

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in December, 2019 in Wuhan, China. Since then, it has continued to spread rapidly in numerous countries, while the search for effective therapeutic options persists. Coronaviruses, including SARS-CoV-2, are known to suppress and evade the antiviral responses of the host organism mediated by interferon (IFN), a family of cytokines that plays an important role in antiviral defenses associated with innate immunity, and has been used therapeutically for chronic viral diseases and cancer. On the other hand, OncoTherad, a safe and effective immunotherapeutic agent in the treatment of non-muscle invasive bladder cancer (NMIBC), increases IFN signaling and has been shown to be a promising therapeutic approach for COVID-19 in a case report that described the rapid recovery of a 78-year-old patient with NMIBC with comorbidities. The present review discusses the possible synergistic action of OncoTherad with vitamin D, zinc and glutamine, nutrients that have been shown to facilitate immune responses mediated by IFN signaling, as well as the potential of this combination as a therapeutic option for COVID-19.

Relationships Between Vitamin D Status and Cytokine: Results from Interferon-Based Therapy in Non-Cirrhotic, Treatment-Naïve Patients with Chronic Hepatitis C Infection

Background

Vitamin D contributes to bone health and extra-skeletal effects. The mechanisms underlying vitamin D metabolism have not been extensively evaluated. The relationships between vitamin D and inflammatory cytokines are debated. Our objective was to investigate whether supplemental interferons are associated with longitudinal change of vitamin D status in humans.

Methods

A total of 48 patients with 24 or 48 weeks of pegylated interferon-α plus ribavirin therapy were examined for serum 25-hydroxyvitamin D (25[OH]D) level before treatment, at the end of treatment, and 24 weeks after treatment. In addition, we analyzed publicly available RNA sequencing data from accession GSE42697 and GSE7123 in the Gene Expression Omnibus.

Findings

The overall sustained virologic response (SVR) rate was 62.5%. There was no statistically significant association between baseline 25(OH)D concentrations and liver fibrosis. In patients with SVR, serum 25(OH)D increased markedly at end-of-treatment and decreased markedly by the end of the 24-week follow-up period. In the non-SVR group, this treatment-dependent change was lost. In gene expression analysis, the vitamin D biosynthesis process was activated in subjects with SVR, but not in patients without SVR. Furthermore, vitamin D receptor (VDR) signaling in peripheral blood mononuclear cells (PBMCs) was triggered in marked responders but not in poor responders.

Conclusion

In the aggregate, these data suggest that interferons have a regulatory influence on vitamin D status that can contribute to VDR signaling in PBMCs.

Effects of vitamin D supplements in patients with chronic hepatitis C: a randomized, multi-center, open label study

BACKGROUND/AIMS

We aimed to assess the role of vitamin D supplementation in the response to pegylated interferon-α (PEG-IFN-α) plus ribavirin (RBV) treatment in patients with chronic hepatitis C (CHC).

METHODS

Our study was a multi-center, randomized controlled trial in 11 hospitals. CHC patients were randomly assigned (1:1) to two groups namely, PEGIFN-α plus RBV (control group) or PEG-IFN-α plus RBV + vitamin D (800 IU daily) (vitamin D group). The primary end-point was the rate of sustained virologic response (SVR).

RESULTS

One hundred forty eight CHC patients were randomly assigned to two groups. Seventy-one patients received the PEG-IFN-α plus RBV and 77 patients received the PEG-IFN-α plus RBV + vitamin D. A total of 105 patients completed the study (control group, 47 vs. vitamin D group, 58). Baseline characteristics were mostly similar in both the groups. There was a modest but non-significant increase in SVR in the vitamin D group compared to the control group with the intention to treat analysis (64.0% vs. 49.3 %, p = 0.071) as well as in the per protocol analysis (control group vs. vitamin D group: 74.5% vs. 84.5%, p = 0.202). Fifty-two patients (73.2%) in the control group and 63 patients (81.8%) in the vitamin D group experienced at least one adverse event. The drop-out rate due to adverse effects was not different between both groups (control group vs. vitamin D group: 19.7% vs. 10.4%, p = 0.111).

CONCLUSION

Vitamin D supplement did not increase SVR in treatment naïve patients with CHC irrespective of genotype.

Controversial Effects of Vitamin D and Related Genes on Viral Infections, Pathogenesis, and Treatment Outcomes

Vitamin D (VD) plays an essential role in mineral homeostasis and bone remodeling. A number of different VD-related genes (VDRG) are required for the metabolic activation of VD and the subsequent induction of its target genes. They include a set of genes that encode for VD-binding protein, metabolic enzymes, and the VD receptor. In addition to its well-characterized skeletal function, the immunoregulatory activities of VD and the related polymorphisms of VDRG have been reported and linked to its therapeutic and preventive actions for the control of several viral diseases. However, in regards to their roles in the progression of viral diseases, inconsistent and, in some cases, contradictory results also exist. To resolve this discrepancy, I conducted an extensive literature search by using relevant keywords on the PubMed website. Based on the volume of hit papers related to a certain viral infection, I summarized and compared the effects of VD and VDRG polymorphism on the infection, pathogenesis, and treatment outcomes of clinically important viral diseases. They include viral hepatitis, respiratory viral infections, acquired immunodeficiency syndrome (AIDS), and other viral diseases, which are caused by herpesviruses, dengue virus, rotavirus, and human papillomavirus. This review will provide the most current information on the nutritional and clinical utilization of VD and VDRG in the management of the key viral diseases. This information should be valuable not only to nutritionists but also to clinicians who wish to provide evidence-based recommendations on the use of VD to virally infected patients.

Effects of vitamin D on drugs: Response and disposal

Vitamin D supplementation and vitamin D deficiency are common in clinical experience and in daily life. Vitamin D not only promotes calcium absorption and immune regulation, but also changes drug effects (pharmacodynamics and adverse reactions) and drug disposal in vivo when combined with various commonly used clinical drugs. The extensive physiological effects of vitamin D may cause synergism effects or alleviation of adverse reactions, and vitamin D's affect on drugs in vivo disposal through drug transporters or metabolic enzymes may also lead to changes in drug effects. Herein, the effects of vitamin D combined with commonly used drugs were reviewed from the perspective of drug efficacy and adverse reactions. The effects of vitamin D on drug transport and metabolism were summarized and analyzed. Hopefully, more attention will be paid to vitamin D supplementation and deficiency in clinical treatment and drug research and development.

CYP24A1 genetic variants in the vitamin D metabolic pathway are involved in the outcomes of hepatitis C virus infection among high-risk Chinese population

BACKGROUND AND AIMS

It has been demonstrated that 1,25-hydroxyvitamin-D3-24-hydroxylase, encoded by CYP24A1 gene, is a key enzyme that neutralizes the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃] in response to hepatitis C virus (HCV) infection. This study aimed to investigate whether CYP24A1 genetic variation is associated with HCV infection outcomes.

METHODS

848 HCV chronically infected subjects, 507 natural clearance subjects, and 1017 uninfected controls were enrolled. Nine single nucleotide polymorphisms (SNPs) in theCYP24A1 gene were genotyped using the Sequenom MassARRAY platform.

RESULTS

After adjusting for age, gender, and routes of infection, logistic regression analyses showed that rs6013897-A was associated with an elevated risk of HCV infection (P<0.05). In addition, this study has also demonstrated that rs6068816-T significantly reduced the risk of chronic HCV infection, while rs3787557-C, rs6022999-G, and rs2248359-T significantly increased the risk of chronic HCV infection (all P<0.05). Haplotype analysis suggested that, compared to the most frequent T_rs6068816T_rs3787557A_rs6022999C_rs2248359 haplotype, the CTGT haplotype (adjusted OR=1.376, 95% CI=1.092-1.735, P=0.007) and CCAC haplotype (adjusted OR=1.483, 95% CI=1.139-1.929, P=0.003) were associated with an increased risk of chronic HCV infection.

CONCLUSION

These findings indicate that SNPs in CYP24A1 gene may contribute to the risk of HCV infection and chronic HCV infection among a high-risk Chinese population.

Vitamin D-Binding protein Gene Polymorphism Predicts Pegylated Interferon-Related HBsAg Seroclearance in HBeAg-Negative Thai Chronic Hepatitis B Patients: A Multicentre Study

Background:

Vitamin D deficiency is related to poor clinical outcomes in patients with chronic hepatitis B virus (HBV) infection.

Methods:

We aimed to investigate the association between the genetic variants in the vitamin D metabolic pathway and the response to pegylated interferon (Peg-IFN) therapy in patients with HBeAg-negative chronic HBV infection. One hundred seven patients treated with Peg-IFN for 48 weeks were selected from 13 specialty hospitals. Eight genotypes of vitamin D cascade genes, including CYP27B1 (rs10877012), DHCR7 (rs12785878), CYP2R1 (rs2060793, rs12794714) and GC (rs4588, rs7041, rs222020, rs2282679), were found.

Results:

Eighty-two patients (83.7%) were infected with HBV genotype C. Eight patients had compensated liver cirrhosis (8.7%). At 24 weeks after treatment discontinuation, 41 patients (42.3%) achieved sustained treatment response, 53 (55.2%) obtained HBV DNA<2,000 IU/ml, 6 (5.6%) gained HBsAg seroclearance, 2 (1.9%) had HBsAg seroconversion and 69 (64.5%) exhibited alanine aminotransferase (ALT) normalization. Multivariate analysis revealed that baseline HBsAg level (OR =0.06, 95% CI: 0.08-0.49, p=0.008) and the GC rs222020 TT genotype (OR=17.72, 95% CI: 1.07-294.38, p=0.04) independently predicted sustained HBsAg seroclearance. In addition, this genotype was a predictor for normalization of ALT (OR=4.61, 95%CI: 1.59-13.40, p=0.005) after therapy. The HBsAg levels at baseline and during and post-treatment tended to be reduced with the GC rs222020 TT compared with the non-TT genotypes. The other studied polymorphisms were not associated with treatment response.

Conclusions:

The GC rs222020 TT genotype, which is a variant in the vitamin D-binding protein gene, could identify HBeAg-negative patients who have a high probability to achieve HBsAg clearance and ALT normalization after treatment with Peg-IFN.

Effect of vitamin D supplementation on sustained virological response in genotype 1/4 chronic hepatitis C treatment-naïve patients from India

Background & objectives:

The effect of vitamin D supplementation on response to antiviral therapy in hepatitis C virus (HCV) genotype 1 and 4 infection still remains unclear, with studies yielding inconsistent results. The aim of the present study was to assess the effect of vitamin D supplementation on treatment outcome in patients with genotype 1/4 chronic hepatitis C (CHC) infection.

Methods:

Sixty consecutive, treatment-naïve, genotype 1 and 4 chronic HCV patients were included in the study. The patients were randomized into two groups: Vitamin D supplemented group received pegylated (PEG)-interferon α-2a 180 μg per week plus ribavirin (RBV) (1000-1200 mg/d) together with vitamin D3 (2000 IU/d) and control group received identical therapy without vitamin D (32 patients).

Results:

There were no significant differences between the two groups in terms of age, sex, body mass index and baseline laboratory values. Lower vitamin D levels were associated with higher grades of fibrosis in liver histology (vitamin D >20 ng/ml - 70% vs vitamin D <20 ng/ml - 37%, P<0.05). Vitamin D supplemented group had similar rapid viral response (40 vs 28%, P=0.36), complete early viral response (53.2 vs 40%, P=0.34), end of treatment response (64 vs 46%, P=0.17) and sustained virological response (SVR) (60 vs 44%, P=0.19) as compared to control group. Interleukin 28B polymorphism [odds ratio (OR)-15.37, 95% confidence interval (CI)-2.32-101.76, P=0.04] and baseline serum vitamin D levels (OR-6.36, 95% CI-1.36-29.61 P=0.02) were independent predictors of SVR in genotype 1/4 CHC. Vitamin D supplementation was not found to be predictor of response in genotype 1/4 CHC on multivariate analysis (OR-2.79, 95% CI- 0.63-12.34, P=0.74).

Interpretation & conclusions:

The present study showed that addition of vitamin D to PEG/RBV combination therapy in treatment-naïve patients who were infected with HCV genotype 1/4 had no effect on the rates of rapid, early and sustained viral responses.

Vitamin D-mediated attenuation of miR-155 in human macrophages infected with dengue virus: Implications for the cytokine response

Clinical manifestations of dengue disease rely on complex interactions between dengue virus (DENV) and host factors that drive altered immune responses, including excessive inflammation. We have recently established that vitamin D can modulate DENV-induced cytokine responses and restrict infection in human macrophages. Cytokine responses are finely regulated by several homeostatic mechanisms, including microRNAs (miRNAs) that can rapidly target specific genes involved in the control of immune signaling pathways. However, the modulation of miRNAs by vitamin D during DENV infection is still unknown. Here, using a qPCR miRNA array we profiled immune-related miRNAs induced by DENV infection in human monocyte-derived macrophages (MDM) differentiated in absence or presence of vitamin D (D₃-MDM). We found several miRNAs differentially expressed in both MDM and D₃-MDM upon DENV infection. Interestingly, from these, a set of 11 miRNAs were attenuated in D₃-MDM as compared to MDM. Gene set enrichment analysis of the predicted mRNA targets of these attenuated miRNAs suggested a predominant role of miR-155-5p in the TLR-induced cytokine responses. Indeed, validation of miR-155-5p attenuation in D₃-MDM was linked to increased expression of its target gene SOCS-1, a key component for TLR4 signaling regulation. Likewise, TLR4 activation with LPS further corroborated the same miR-155-5p/SOCS-1 negative correlation observed in D₃-MDM upon DENV exposure. Moreover, D₃-MDM differentiation induced down-regulation of surface TLR4 that was linked to less TLR4/NF-κB-derived secretion of IL-1β. These data suggest a key role of vitamin D in the control of inflammatory cytokine responses during DENV infection of human macrophages via the TLR4/NF-κB/miR-155-5p/SOCS-1 axis.

Vitamin D derivatives inhibit hepatitis C virus production through the suppression of apolipoprotein

Supplementation with vitamin D (VD) has been reported to improve the efficacy of interferon-based therapy for chronic hepatitis C. We found that 25-hydroxyvitamin D₃ (25-(OH)D₃), one of the metabolites of VD, has antiviral effects by inhibiting the infectious virus production of the hepatitis C virus (HCV). In this study, to clarify the underlying mechanisms of the anti-HCV effects, we searched VD derivatives that have anti-HCV effects and identified the common target molecule in the HCV life cycle by using an HCV cell culture system. After infection of Huh-7.5.1 cells with cell culture-generated HCV, VD derivatives were added to culture media, and the propagation of HCV was assessed by measuring the HCV core antigen levels in culture media and cell lysates. To determine the step in the HCV life cycle affected by these compounds, the single-cycle virus production assay was used with a CD81-negative cell line. Of the 14 structural derivatives of VD, an anti-HCV effect was detected in 9 compounds. Cell viability was not affected by these effective compounds. The 2 representative VD derivatives inhibited the infectious virus production in the single-cycle virus production assay. Treatment with these compounds and 25-(OH)D₃ suppressed the expression of apolipoprotein A1 and C3, which are known to be involved in infectious virus production of HCV, and the knockdown of these apolipoproteins reduced infectious virus production. In conclusion, we identified several compounds with anti-HCV activity by screening VD derivatives. These compounds reduce the infectious virus production of HCV by suppressing the expression of apolipoproteins in host cells.

Vitamin D deficiency in hepatitis C virus infection: what is old? what is new?

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Vitamin D supplementation for chronic liver diseases in adults

BACKGROUND

Vitamin D deficiency is often reported in people with chronic liver diseases. Therefore, improving vitamin D status could have a beneficial effect on people with chronic liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of vitamin D supplementation in people with chronic liver diseases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, and Conference Proceedings Citation Index - Science. We also searched databases of ongoing trials and the World Health Organization International Clinical Trials Registry Platform. We scanned bibliographies of relevant publications and asked experts and pharmaceutical companies for additional trials. All searches were up to January 2017.

SELECTION CRITERIA

Randomised clinical trials that compared vitamin D at any dose, duration, and route of administration versus placebo or no intervention in adults with chronic liver diseases. Vitamin D could have been administered as supplemental vitamin D (vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol)), or an active form of vitamin D (1α-hydroxyvitamin D (alfacalcidol), 25-hydroxyvitamin D (calcidiol), or 1,25-dihydroxyvitamin D (calcitriol)).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We contacted authors of the trials to ask for missing information. We conducted random-effects and fixed-effect meta-analyses. For dichotomous outcomes, we calculated risk ratios (RRs), and for continuous outcomes, we calculated mean differences (MD), both with 95% confidence intervals (CI) and Trial Sequential Analyses-adjusted CIs. We calculated Peto odds ratio (OR) for rare events. We considered risk of bias in domains to assess the risk of systematic errors. We conducted Trial Sequential Analyses to control the risk of random errors. We assessed the quality of the evidence with GRADE.

MAIN RESULTS

We included 15 randomised clinical trials with 1034 participants randomised. All trials had a parallel group design. Nine trials were conducted in high-income countries and six trials in middle-income countries. All trials were at high risk of bias. Six trials included participants with chronic hepatitis C, four trials included participants with liver cirrhosis, four trials included participants with non-alcoholic fatty liver disease, and one trial included liver transplant recipients. All included trials reported the baseline vitamin D status of participants. Participants in six trials had baseline 25-hydroxyvitamin D levels at or above vitamin D adequacy (20 ng/mL), while participants in the remaining nine trials were vitamin D insufficient (less than 20 ng/mL). All trials administered vitamin D orally. Mean duration of vitamin D supplementation was 0.5 years and follow-up was 0.6 years. Eleven trials (831 participants; 40% women; mean age 52 years) tested vitamin D3, one trial (18 men; mean age 61 years) with three intervention groups tested vitamin D2 and 25-dihydroxyvitamin D in separate groups, and three trials (185 participants; 55% women; mean age 55 years) tested 1,25-dihydroxyvitamin D. Seven trials used placebo, and eight trials used no intervention in the control group.The effect of vitamin D on all-cause mortality at the end of follow-up is uncertain because the results were imprecise (Peto OR 0.70, 95% CI 0.09 to 5.38; I2 = 32%; 15 trials; 1034 participants; very low quality evidence). Trial Sequential Analysis on all-cause mortality was performed based on a mortality rate in the control group of 10%, a relative risk reduction of 28% in the experimental intervention group, a type I error of 2.5%, and type II error of 10% (90% power). There was no diversity. The required information size was 6396 participants. The cumulative Z-curve did not cross the trial sequential monitoring boundary for benefit or harm after the 15th trial, and the Trial Sequential Analyses-adjusted CI was 0.00 to 2534.The effect of vitamin D on liver-related mortality (RR 1.62, 95% CI 0.08 to 34.66; 1 trial; 18 participants) and on serious adverse events such as hypercalcaemia (RR 5.00, 95% CI 0.25 to 100.8; 1 trial; 76 participants), myocardial infarction (RR 0.75, 95% CI 0.08 to 6.81; 2 trials; 86 participants), and thyroiditis (RR 0.33 95% CI 0.01 to 7.91; 1 trial; 68 participants) is uncertain because the results were imprecise. The evidence on all these outcomes is of very low quality. The effect of vitamin D3 on non-serious adverse events such as glossitis (RR 3.70, 95% CI 0.16 to 87.6; 1 trial; 65 participants; very low quality of evidence) is uncertain because the result was imprecise.Due to few data, we did not conduct Trial Sequential Analysis on liver-related mortality, and serious and non-serious adverse events.We found no data on liver-related morbidity and health-related quality of life in the randomised trials included in this review.

AUTHORS' CONCLUSIONS

We are uncertain as to whether vitamin D supplements in the form of vitamin D3, vitamin D2, 1,25-dihydroxyvitamin D, or 25-dihydroxyvitamin D have important effect on all-cause mortality, liver-related mortality, or on serious or non-serious adverse events because the results were imprecise. There is no evidence on the effect of vitamin D supplementation on liver-related morbidity and health-related quality of life. Our conclusions are based on few trials with an insufficient number of participants and on lack of data on clinically important outcomes. In addition, the analysed trials are at high risk of bias with significant intertrial heterogeneity. The overall quality of evidence is very low.

Human macrophages differentiated in the presence of vitamin D3 restrict dengue virus infection and innate responses by downregulating mannose receptor expression

Background

Severe dengue disease is associated with high viral loads and overproduction of pro-inflammatory cytokines, suggesting impairment in the control of dengue virus (DENV) and the mechanisms that regulate cytokine production. Vitamin D₃ has been described as an important modulator of immune responses to several pathogens. Interestingly, increasing evidence has associated vitamin D with decreased DENV infection and early disease recovery, yet the molecular mechanisms whereby vitamin D reduces DENV infection are not well understood.

Methods and principal findings

Macrophages represent important cell targets for DENV replication and consequently, they are key drivers of dengue disease. In this study we evaluated the effect of vitamin D₃ on the differentiation of monocyte-derived macrophages (MDM) and their susceptibility and cytokine response to DENV. Our data demonstrate that MDM differentiated in the presence of vitamin D₃ (D₃-MDM) restrict DENV infection and moderate the classical inflammatory cytokine response. Mechanistically, vitamin D₃-driven differentiation led to reduced surface expression of C-type lectins including the mannose receptor (MR, CD206) that is known to act as primary receptor for DENV attachment on macrophages and to trigger of immune signaling. Consequently, DENV bound less efficiently to vitamin D₃-differentiated macrophages, leading to lower infection. Interestingly, IL-4 enhanced infection was reduced in D₃-MDM by restriction of MR expression. Moreover, we detected moderate secretion of TNF-α, IL-1β, and IL-10 in D₃-MDM, likely due to less MR engagement during DENV infection.

Conclusions/Significance

Our findings reveal a molecular mechanism by which vitamin D counteracts DENV infection and progression of severe disease, and indicates its potential relevance as a preventive or therapeutic candidate.

Dengue represents a major worldwide concern for public health. Clinical complications rely on vascular leak of fluids and molecules from the bloodstream that leads to a potentially fatal hemodynamic compromise. Disease progression has been related to poor control of dengue virus (DENV) dissemination and excessive production of pro-inflammatory mediators that affect the endothelial function. Vitamin D has been shown to modulate immune responses and to alleviate dengue disease. Here, we studied how addition of vitamin D during macrophage differentiation modulates the functional features of these cells in the context of DENV infection. We observed that vitamin D reduced susceptibility of these cells to DENV infection and down-regulated the virus-induced cytokine response. This phenotype was attributed to downregulation of MR, a molecule hijacked by the virus to gain entry into the cells and a key receptor of the MR/CLEC5A complex that links binding and immune activation during DENV infection. Our study sheds light on the mechanism by which vitamin D can restrict DENV dissemination and the cytokine response in macrophages, indicating the potential relevance of this hormone as a preventive and therapeutic candidate.

Efficacy of vitamin D supplementation in combination with conventional antiviral therapy in patients with chronic hepatitis C infection: a meta-analysis of randomised controlled trials

BACKGROUND

Although a contributory role of vitamin D levels for the development of chronic hepatitis C has been suggested, the efficacy of vitamin D supplementation in combination with conventional antiviral therapy consisting of pegylated interferon-α (Peg-IFN-α) injection and oral ribavirin (RBV) remains unclear. We investigated its efficacy in the treatment of chronic hepatitis C via a meta-analysis of randomised controlled trials.

METHODS

We searched PubMed, EMBASE, the Cochrane Library, ClinicalTrials.gov and the bibliographies of relevant articles to locate additional publications in September 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria.

RESULTS

Of 522 articles meeting our initial criteria, a total of seven open-label, randomised controlled trials involving 548 participants, were included in the final analysis. Vitamin D supplementation in combination with Peg-IFN-α injection and oral RBV significantly increased the rate of viral response for hepatitis C at 24 weeks after treatment in a random-effects meta-analysis (relative risk = 1.30; 95% confidence interval = 1.04-1.62; I² = 75.9%). Also, its significant efficacy was observed in patients with hepatitis C virus genotype 1, which is known to be refractory to antiviral therapy.

CONCLUSIONS

In summary, we observed that additional use of vitamin D has a positive effect on sustained viral response rates of patients with chronic hepatitis C infection. However, we cannot establish the efficacy because of substantial heterogeneity, a small sample size and a low methodological quality.

Vitamin D-related gene polymorphism predict treatment response to pegylated interferon-based therapy in Thai chronic hepatitis C patients

Background

Patients with chronic hepatitis C (HCV) infection have high prevalence of vitamin D deficiency. Genome-wide association study data has showed that several genetic variants within vitamin D cascade affect vitamin D function. This study aimed to determine whether genetic polymorphisms of genes in the vitamin D pathway are associated with treatment responses to pegylated interferon (PEG-IFN)-based therapy in patients with chronic HCV infection.

Methods

The study included 623 Thai patients from 2 university hospitals diagnosed with chronic HCV infection who were treated with a PEG-IFN and ribavirin. Patients were genotyped for functional variants on vitamin D synthetic pathway including GC (rs4588, rs7041, rs22020, rs2282679), CYP2R1 (rs2060793, rs12794714), CYP27B1 (rs10877012), and DHCR7 (rs12785878). Pre-treatment predictors of sustained virologic response (SVR) at 24 weeks following discontinuation of therapy were identified using a logistic regression analysis.

Results

SVR was achieved by 60.5% of patients (52.9% with HCV genotype 1; 66.7% with HCV non-genotype 1). In 44.6% of HCV genotype 1-infected patients, only the variant rs12785878 in the DHCR7 locus was significantly associated with an SVR. HCV genotype 1 patients who had DHCR7 rs12785878 GT/TT had a higher rate of SVR than those with the GG allele (59.7% vs. 43.4%, P = 0.03), but in HCV non-genotype 1-infected patients, the SVR rate did not differ between the two groups (63.3% and 59.1% for GT/TT and GG allele, P = 0.54). By multivariate analysis, liver fibrosis stage 0–1 (OR = 5.00; 95% CI, 2.02–12.37; P < 0.001), and DHCR7 rs12785878 GT/TT allele (OR = 2.69; 95% CI, 1.03–7.05; P = 0.04) were independent pre-treatment predictors of SVR following PEG-IFN-based therapy in HCV genotype 1 patients. Baseline HCV RNA < 400,000 IU/ml (OR = 1.96; 95% CI, 1.13–3.39; P = 0.02) was the only independent predictor of SVR in HCV non-genotype 1 patients. The polymorphisms of GC, CYP2R1 and CYP27B1 were not associated with treatment outcome even in genotype 1 or non-genotype 1 HCV infection.

Conclusion

The DHCR7 polymorphism may be a pre-treatment predictive marker for response to PEG-IFN-based therapy in chronic HCV genotype 1 infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-017-0613-x) contains supplementary material, which is available to authorized users.

Effect of season and sunlight on viral kinetics during hepatitis C virus therapy

Background and aims

Rapid viral response (RVR) during antiviral treatment for hepatitis C virus (HCV) predicts sustained viral response (SVR). Recently, vitamin D levels have been associated with SVR. As sunlight is the most important source of vitamin D and shows seasonal variation, we evaluated the effect of season on viral kinetics during peginterferon/ribavirin-based therapy for HCV.

Methods

Consecutive HCV patients treated with peginterferon/ribavirin and boceprevir/ telaprevir (June 2011–July 2014) were included. Patients were grouped according to season when therapy was initiated (Season A: May–October and Season B: November–April) depending on hours of daily sunlight. Multiple logistic regression analysis included factors known to influence SVR to treatment. The dependent variables were undetectable viral load (VL) or VL ≤15 UI/mL (VL ≤15) at weeks 4, 8 and 12, end of treatment and SVR.

Results

The study included 930 patients (66.8% men; median 54 years) treated with telaprevir (n=537) or boceprevir, without (n=481) or with lead-in therapy of peginterferon/ribavirin. Baseline characteristics of patients in Season A (45.3%, n=421) and Season B groups were similar. Overall, a higher rate of RVR (23.5% vs 16.1%, p=0.005) and VL ≤15 (51.0% vs 38.6%, p≤0.001) was observed in patients starting treatment during Season A versus Season B. By logistic regression analysis, initiating treatment in Season A proved to be an independent predictor of RVR and VL ≤15.

Conclusions

In our setting, seasonality affects viral kinetics in HCV genotype 1 patients treated with peginterferon/ribavirin-based therapy. Our findings support the hypothesis that vitamin D influences viral response to peginterferon/ribavirin-based therapy.

Vitamin D in liver disease: Current evidence and potential directions

Consistent with its multifaceted nature, growing evidence links vitamin D with hepatic disease. In this review, we summarise the roles of vitamin D in different liver pathologies and explore the clinical utility of vitamin D-based treatments in hepatology. We find that the small number of clinical trials coupled with the profound heterogeneity of study protocols limits the strength of evidence needed to ascribe definite clinical value to the hormone in liver disease. Nevertheless, the experimental data is promising and further bench and bedside studies will likely define a clearer role in hepatic therapeutics.

Antimicrobial peptide LL-37 attenuates infection of hepatitis C virus

AIM

Although recent studies indicate that supplementation with vitamin D (VD) potentiates a sustained viral response by interferon-based therapy to chronic hepatitis C, detailed mechanisms are not fully defined. The production of cathelicidin, an antimicrobial peptide, has been demonstrated to be part of the VD-dependent antimicrobial pathway in innate immunity. Cathelicidin is known to directly kill or inhibit the growth of microbial pathogens including mycobacteria and viruses.

METHODS

We used a hepatitis C virus (HCV) cell culture system to clarify the anti-HCV effects of the human cathelicidin, LL-37. HuH-7 cells were administrated with LL-37 and infected with cell culture-generated HCV (HCVcc). HCV propagation was estimated by measuring the level of HCV core antigen (Ag).

RESULTS

Treatment with LL-37 resulted in decreased intra- and extracellular levels of HCV core Ag, suggesting inhibition of HCV propagation. To assess the effects of LL-37 on HCV replication, JFH-1 subgenomic replicon RNA-transfected cells were treated with LL-37. However, inhibition of HCV replication was not detected by this assay. To clarify the effects on HCV infection, we treated HCVcc with LL-37 and removed the antimicrobial peptide prior to use of the virus in infection. This exposure of HCVcc to LL-37 diminished the infectivity titers in a dose-dependent fashion. Iodixanol density gradient analysis revealed that the peak fraction of infectivity titer was eliminated by LL-37 treatment.

CONCLUSION

The VD-associated antimicrobial peptide LL-37 attenuated the infectivity of HCV. This anti-HCV effect of LL-37 may explain the contribution of VD to the improved efficacy of interferon-based therapy.

Vitamin D-Regulated MicroRNAs: Are They Protective Factors against Dengue Virus Infection?

Over the last few years, an increasing body of evidence has highlighted the critical participation of vitamin D in the regulation of proinflammatory responses and protection against many infectious pathogens, including viruses. The activity of vitamin D is associated with microRNAs, which are fine tuners of immune activation pathways and provide novel mechanisms to avoid the damage that arises from excessive inflammatory responses. Severe symptoms of an ongoing dengue virus infection and disease are strongly related to highly altered production of proinflammatory mediators, suggesting impairment in homeostatic mechanisms that control the host's immune response. Here, we discuss the possible implications of emerging studies anticipating the biological effects of vitamin D and microRNAs during the inflammatory response, and we attempt to extrapolate these findings to dengue virus infection and to their potential use for disease management strategies.

Association of vitamin D receptor gene polymorphisms with response to peginterferon plus ribavirin in Asian patients with chronic hepatitis C

BACKGROUND/PURPOSE

Recent studies have shown that serum vitamin D deficiency is a negative predictor of response to peginterferon plus ribavirin therapy for Caucasian patients with chronic hepatitis C (CHC). Whether vitamin D receptor (VDR) gene polymorphisms associate with antiviral response in Asian CHC patients remains unclear.

METHODS

We recruited 139 Asian patients with CHC genotype-1 who achieved 80/80/80 adherence of response-guided peginterferon plus ribavirin therapy. BsmI rs1544410, ApaI rs7975232, and TaqI rs731236 were genotyped and related to clinical and virological features and to treatment outcome.

RESULTS

Patients carrying bAt [CCA] haplotype (p=0.033), ApaI CC genotype (p = 0.033), and TaqI AA genotype (p = 0.037) had a higher HCV load as compared to those with other haplotypes, ApaI CA/AA genotype and TaqI AG genotype, respectively. A sustained virological response (SVR) was achieved in 74 (53%) of the patients. Polymorphisms in VDR gene did not correlate with rapid virological response and SVR achievement. Stepwise logistic regression analysis showed that rs12979860 CC type [odds ratio (OR): 5.56, p=0.007], platelet counts ≥ 15 × 10(10)/L (OR: 4.80, p=0.001), and rapid virological response achievement (OR: 8.36, p<0.001) were independent factors of SVR.

CONCLUSION

Despite their associations with high hepatitis C virus load, VDR gene polymorphisms are not related to the response to peginterferon plus ribavirin therapy in Asian CHC patients.

Randomized study comparing vitamin D3 and 1α-Hydroxyvitamin D3 in combination with pegylated interferon/ribavirin therapy for chronic hepatitis C

BACKGROUND AND AIM

An intention-to-treat prospective randomized study was carried out to compare the potentiation of antiviral efficacies between cholecalciferol, non-activated vitamin D3 supplement, and alfacalcidol, activated 1α-Hydroxyvitamin D3 [1α (OH)-vitamin D3].

METHODS

Chronic hepatitis patients with genotype 1b hepatitis C virus (HCV) infection showing serum HCV-RNA levels greater than 5 Log IU/mL received oral administration of cholecalciferol (2000 IU/day) or alfacalcidol (0.5 μg/day) for 4 weeks, and then they were given pegylated interferon (Peg-IFN)-α2a plus ribavirin therapy in combination with either vitamin D3 for 48 or 72 weeks according to the response-guided manner.

RESULTS

A total of 36 patients were evaluated. Serum 25-hydroxyvitamin D3 [25(OH)-D3] levels were increased only in patients in the cholecalciferol group during the lead-in vitamin D administration, and the levels at 4 weeks were higher in these patients than in those in the alfacalcidol group (P < 0.001), while serum 1α,25-dihydroxyvitamin D3 [1α,25(OH)2 -D3] levels were not different between both groups. Rapid virological response was obtained in six (33%) patients in the cholecalciferol group; the ratio was higher than that in the alfacalcidol group (one patient; 6%, P < 0.05). Serum HCV-RNA level decline at 4 weeks of combined Peg-IFN-α2a plus ribavirin therapy compared with the baseline levels were greater in the cholecalciferol group (4.6 Log IU/mL) than in the alfacalcidol group (3.5 Log IU/mL) (P < 0.05), when four patients showing null response to the therapy was excluded. However, both complete early virological response and sustained viral response rates were not different between both groups.

CONCLUSION

Cholecalciferol produced superior potentiation of the antiviral activity than alfacalcidol only during the initial periods of combined Peg-IFN-α2a plus ribavirin therapy through upregulation of serum 25(OH)-D3 levels.

Influencing factors on serum 25-hydroxyvitamin D3 levels in Japanese chronic hepatitis C patients

Background

Serum 25-hydroxyvitamin D₃ levels are generally lower in chronic hepatitis C patients than in healthy individuals. The purpose of this study is to clarify the factors which affect serum 25-hydroxyvitamin D₃ levels using data obtained from Japanese chronic hepatitis C patients.

Methods

The subjects were 619 chronic hepatitis C patients. Serum 25-hydroxyvitamin D₃ levels were measured by using double-antibody radioimmunoassay between April 2009 and August 2014. Serum 25-hydroxyvitamin D₃ levels of 20 ng/mL or less were classified as vitamin D deficiency, and those with serum 25-hydroxyvitamin D₃ levels of 30 ng/mL or more as vitamin D sufficiency. The relationship between patient-related factors and serum 25-hydroxyvitamin D₃ levels was analyzed.

Results

The cohort consisted of 305 females and 314 males, aged between 18 and 89 years (median, 63 years). The median serum 25-hydroxyvitamin D₃ level was 21 ng/mL (range, 6–61 ng/mL). On the other hand, the median serum 25-hydroxyvitamin D₃ level in the healthy subjects was 25 ng/mL (range, 7–52), being significantly higher than that those in 80 chronic hepatitis C patients matched for age, gender, and season (p = 1.16 × 10⁻⁸). In multivariate analysis, independent contributors to serum 25-hydroxyvitamin D₃ deficiency were as follows: female gender (p = 2.03 × 10⁻⁴, odds ratio = 2.290, 95 % confidence interval = 1.479–3.545), older age (p = 4.30 × 10⁻⁴, odds ratio = 1.038, 95 % confidence interval = 1.017–1.060), cold season (p = 0.015, odds ratio = 1.586, 95 % confidence interval = 1.095–2.297), and low hemoglobin level (p = 0.037, odds ratio = 1.165, 95 % confidence interval = 1.009–1.345). By contrast, independent contributors to serum 25-hydroxyvitamin D₃ sufficiency were male gender (p = 0.001, odds ratio = 3.400, 95 % confidence interval = 1.635–7.069), warm season (p = 0.014, odds ratio = 1.765, 95 % confidence interval = 1.117–2.789) and serum albumin (p = 0.016, OR = 2.247, 95 % CI = 1.163–4.342).

Conclusions

Serum 25-hydroxyvitamin D₃ levels in chronic hepatitis C Japanese patients were influenced by gender, age, hemoglobin level, albumin and the season of measurement.

Boceprevir and telaprevir for chronic genotype 1 hepatitis C virus infection. A systematic review and meta-analysis

BACKGROUND

Treatment of hepatitis C virus (HCV) infection with newer direct-acting antivirals is unrealistic in some countries because of the lack of availability.

AIM

Assess benefits and harms of boceprevir (BOC) and telaprevir (TLV) in treatment of genotype 1 HCV infection, and identifying subgroups with most benefit.

MATERIAL AND METHODS

Search from 2009-2013 in PubMed, EMBASE, and "gray literature" of published and unpublished randomized trials reporting sustained viral response (SVR) or adverse events (AE) with BOC or TLV + pegylated interferon and ribavirin (PR) in HCV-infected patients; cohorts or case reports for comparison protease inhibitors (PI), evaluation of predictors of SVR, and resistant variants. Cochrane guidelines were applied. Comparisons between PI + PR vs. PR were performed. Main outcomes were expressed as risk-ratios with 95% CIs. Meta-regression and trial sequential analysis were performed.

RESULTS

33 studies (10,525 patients) were analyzed. SVR was higher for PI + PR (RR, 2.05; 95% CI 1.70-2.48). In meta-regression, previously treated patients exhibited greater benefit from PI + PR (RR, 3.47; 95% CI, 2.78-4.33). AE were higher with PI + PR (RR, 1.01; 95% CI, 1-1.03; NNH 77.59), also the discontinuation rate (RR, 1.69; 95% CI, 1.36-2.10, NNH, 18). Predictors of SVR were IL-28 TT, nonblack race, low viral load, age, no cirrhosis, statin use, undetectable viral load at the first anemia episode and at week 2 of treatment, and low IL-6 levels. In conclusion SVR was higher in patients treated with PIs, patients previously exposed to PR showed superior response rates. Specific predictors will determine the best candidates for treatments that will offer real-life therapeutic alternatives.

Vitamin D deficiency in chronic liver disease

Vitamin D is an important secosteroid hormone with known effect on calcium homeostasis, but recently there is increasing recognition that vitamin D also is involved in cell proliferation and differentiation, has immunomodulatory and anti-inflammatory properties. Vitamin D deficiency has been frequently reported in many causes of chronic liver disease and has been associated with the development and evolution of non-alcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) virus infection. The role of vitamin D in the pathogenesis of NAFLD and CHC is not completely known, but it seems that the involvement of vitamin D in the activation and regulation of both innate and adaptive immune systems and its antiproliferative effect may explain its importance in these liver diseases. Published studies provide evidence for routine screening for hypovitaminosis D in patients with liver disease. Further prospectives studies demonstrating the impact of vitamin D replacement in NAFLD and CHC are required.

Relationship of vitamin D status with advanced liver fibrosis and response to hepatitis C virus therapy: a meta-analysis

There is growing evidence that vitamin D is related to chronic hepatitis C (CHC) pathogenicity. We analyzed the relationship of vitamin D status with advanced liver fibrosis (ALF) in CHC treatment-naïve patients and sustained virologic response (SVR) in CHC patients on pegylated interferon alpha plus ribavirin (pegIFNα/ribavirin) therapy. We performed a meta-analysis of all eligible studies published to date (April, 2014) in PubMed, SCOPUS, LILACS, and the Cochrane Library, assessing plasma/serum vitamin D levels related to ALF and/or SVR. Pooled odds ratios (ORs) were estimated by either fixed or random effects models. Fourteen studies were selected from the literature search, seven for ALF (1,083 patients) and 11 for SVR (2,672 patients). For liver fibrosis, low vitamin D status was related to a diagnosis of ALF, with the cutoffs of 10 ng/mL (OR=2.37, 95% confidence interval [CI]=1.20, 4.72) and 30 ng/mL (OR=2.22, 95% CI=1.24, 3.97) being significant, and a near-significance for 20 ng/mL (OR=1.44, 95% CI=0.99, 2.12). Regarding SVR, a significant heterogeneity among studies was found (P<0.001), and we only found a significant association with SVR for a vitamin D cutoff of 20 ng/mL (OR=0.53, 95% CI=0.31, 0.91). When meta-analysis was performed excluding the outliers, significant pooled ORs were found for all patients (10 ng/mL [OR=0.48, 95% CI=0.34, 0.67] and 20 ng/mL [OR=0.58, 95% CI=0.45, 0.76]) and GT1/4 patients (10 ng/mL [OR=0.53, 95% CI=0.34, 0.81] and 20 ng/mL [OR=0.54, 95% CI=0.39, 0.74]).

CONCLUSION

Low vitamin D status in CHC patients is associated with a higher likelihood of having ALF and lower odds of achieving SVR following pegIFNα/ribavirin therapy.