D-livering the message: the importance of vitamin D status in chronic liver disease

Vitamin D is synthesized predominantly in the liver and functions as an important secosteroid hormone with pleiotropic effects. While its key regulatory role in calcium and bone homeostasis is well established, recently there is increasing recognition that vitamin D also regulates cell proliferation and differentiation, and has immunomodulatory, anti-inflammatory and anti-fibrotic properties. These non-skeletal effects are relevant in the pathogenesis and treatment of many causes of chronic liver disease. Vitamin D deficiency is frequently present in chronic liver disease and may predict non-response to antiviral therapy in chronic hepatitis C. Small studies suggest that vitamin D supplementation improves sustained viral response rates, while 1α-hydroxylase polymorphisms and vitamin D-binding protein are also implicated in therapeutic outcomes. Vitamin D deficiency also closely relates to the severity of non-alcoholic fatty liver disease (NAFLD) and is implicated in the pathogenesis of insulin resistance, a key factor in the development of NAFLD. In preclinical studies, phototherapy and vitamin D supplementation ameliorate NAFLD histopathology, while vitamin D is a powerful anti-fibrotic against thioacetamide liver injury. In liver transplant recipients severe vitamin D deficiency predicts, and vitamin D supplementation prevents, acute cellular rejection. The role of vitamin D in the activation and regulation of both innate and adaptive immune systems may explain its importance in the above liver diseases. Further prospective studies are therefore warranted to investigate the therapeutic impact of vitamin D supplementation in chronic liver disease.

Systematic review: current concepts and challenges for the direct-acting antiviral era in hepatitis C cirrhosis

BACKGROUND

The burden of HCV cirrhosis is high and projected to increase significantly over the next decade. While interferon therapy is problematic in HCV cirrhosis, the era of direct-acting anti-viral (DAA) therapy provides effective treatment for patients with cirrhosis.

AIM

To systematically review the results of DAA therapy to date in patients with HCV cirrhosis, and highlight the ongoing challenges for DAA therapy in this population.

METHODS

A structured Medline search was conducted to obtain phase II and III HCV trials in patients with cirrhosis. Citations from review articles were cross-referenced and conference abstracts from EASL and AASLD liver meetings for the preceding 3 years were reviewed manually. Keywords used included hepatitis C, cirrhosis and the DAA's: sofosbuvir, ledipasvir, velpatasvir, grazoprevir, elbasvir, daclatasvir, beclabuvir, asunaprevir, simeprevir, paritaprevir, ombitasvir and dasabuvir.

RESULTS

Successful direct-acting anti-viral treatment is now possible in patients with HCV-related cirrhosis including those with liver decompensation with several regimens now offering sustained virological response (SVR) of 90-95%. Overall success rates in GT1 cirrhosis are excellent while GT3-infected patients with cirrhosis remain hard to cure. The pangenotypic combination of sofosbuvir and velpatasvir holds promise for GT3 cirrhosis achieving SVR of ~90%.

CONCLUSIONS

Potent DAA therapies provide much needed, safe and highly effective treatment options for persons with HCV cirrhosis including those previously deemed unsuitable for treatment. Combination therapy with two or more classes of drug is essential to achieve high efficacy and minimise viral resistance, with the role of ribavirin still under evaluation. However, several challenges remain including the hard-to-cure groups of GT3 cirrhosis and direct-acting anti-viral failures, and managing drug-drug interactions.

Vitamin D status does not predict sustained virologic response or fibrosis stage in chronic hepatitis C genotype 1 infection

BACKGROUND & AIMS

The relationship between vitamin D status and response to antiviral therapy and liver histology in hepatitis C virus genotype 1 (HCV-1) infection remains unclear, with studies to date yielding inconsistent results and failing to use reference assay methodology. We therefore analyzed pre-treatment 25-hydroxyvitamin D [25(OH)D] level, using reference liquid chromatography-tandem mass spectrometry methodology, in a cohort of treatment-naïve patients with HCV-1 to evaluate the association between vitamin D status, virologic response, and liver histology.

METHODS

274 patients, with pre-treatment liver biopsy and up to 48 weeks of pegylated interferon alfa-2a plus ribavirin therapy, were tested for serum 25(OH)D level. Predictors of sustained virologic response (SVR), and variables associated with fibrosis stage, activity grade and 25(OH)D status were identified using multivariate analysis.

RESULTS

Mean 25(OH)D level was 79.6 nmol/L, with a prevalence of 25(OH)D <75 nmol/L and <50 nmol/L of 48% and 16%, respectively. Season, race and geographic latitude were independent predictors of 25(OH)D status, while vitamin D deficiency was more prevalent in those with high activity grade (21% vs. 11%; p=0.03). Mean 25(OH)D level was lower (76.6 vs. 84.7 nmol/L; p=0.03) and 25(OH)D <75 nmol/L more prevalent (53% vs. 40%; p=0.03) in patients with an SVR, but no association between 25(OH)D status and SVR was found in multivariate analysis. Mean 25(OH)D level did not vary between fibrosis stage or activity grade.

CONCLUSIONS

Baseline 25(OH)D level is not independently associated with SVR or fibrosis stage in HCV-1, but vitamin D deficiency is associated with high activity grade.

Liver stiffness and the prediction of clinically significant portal hypertension and portal hypertensive complications

OBJECTIVE

Clinically significant portal hypertension (CSPH) is associated with increased risk of liver disease complications, but its identification requires invasive methods. Liver stiffness (LS) measurement via transient elastography correlates with the presence of CSPH. We, therefore, evaluated LS as a noninvasive tool in the prediction of CSPH and portal hypertensive complications.

MATERIAL AND METHODS

Ninety-five consecutive patients successfully underwent measurement of hepatic venous pressure gradient (HVPG) and LS on the same day. Recent laboratory tests were correlated. Patients were followed up for development of portal hypertensive complications. Predictors of CSPH and complications were identified.

RESULTS

Seventy-six (80%) were male and mean age was 56.8 ± 9.3 years. Ninety-three percent and 72% of patients had cirrhosis and esophageal varices, respectively. Only LS (r(2) = 0.38; p < 0.0001) and international normalized ratio (r(2) = 0.21; p = 0.02) were independently associated with HVPG. An LS >29.0 kilopascal (kPa) predicted CSPH with 71.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 56.0% negative predictive value (NPV). An LS <25.0 kPa in those with platelet count >150 × 10(9)/L excluded CSPH with 91.7% sensitivity, 100% specificity, 100% PPV, and 90% NPV. Ninety patients were followed up for a median duration of 15.1 months. CSPH and LS >34.5 kPa predicted portal hypertensive complications with 100% and 75.0% sensitivity, 40.3% and 69.4% specificity, 43.1% and 52.5% PPV, and 100% and 86.2% NPV, respectively.

CONCLUSION

LS shows promise as a noninvasive marker of CSPH and portal hypertensive complications. Combining LS with platelet count improves diagnostic accuracy in the exclusion of CSPH.

Utility of transient elastography in the non-invasive evaluation of cystic fibrosis liver disease

BACKGROUND

Liver disease frequently complicates cystic fibrosis (CF), with CF liver disease (CFLD) a leading cause of death. Liver biopsy is rarely performed because of the patchy nature of the disease. Transient elastography can reliably stage liver fibrosis via liver stiffness measurement (LSM).

AIMS

To evaluate LSM as a diagnostic tool in adults with CFLD.

METHODS

Fifty adult patients with CF were prospectively studied: 25 with CFLD and 25 without CFLD. The presence of CFLD and portal hypertension (PHT) was assessed according to strict established criteria based on serial biochemistry and imaging. All patients underwent LSM; APRI, Hepascore(®) and Forns score were calculated.

RESULTS

Median LSM was higher in those with CFLD [8.1 kPa (IQR 6.8-9.5) vs. 5.0 kPa (IQR 4.1-5.6); P < 0.001]. On multivariate analysis, LSM was the only variable associated with CFLD (OR 2.74, 95% CI 1.53-4.89; P = 0.001). AUROC for LSM predicting CFLD was 0.87 (95% CI 0.77-0.98) and an LSM ≥ 6.8 kPa predicted CFLD with 76.0% sensitivity and 92.0% specificity. Median LSM was higher in those with PHT [15.7 kPa (IQR 9.2-17.2) vs. 5.4 kPa (IQR 4.3-6.8); P < 0.001]. The AUROC for LSM predicting the presence of PHT was 0.96 (95% CI 0.92-1.00). An LSM cut-off of ≥ 8.9 kPa predicted the presence of PHT with 87.5% sensitivity, 90.5% specificity, 63.6% positive predictive value and 92.9% negative predictive value.

CONCLUSIONS

LSM is an accurate and reliable non-invasive tool in assessing CFLD and PHT. An LSM ≥ 6.8 kPa is highly suggestive of CFLD and an LSM <8.9 kPa reliably excludes PHT.

Vitamin D level and sustained virologic response to interferon-based antiviral therapy in chronic hepatitis C: a systematic review and meta-analysis

BACKGROUND & AIMS

The baseline 25-hydroxyvitamin D (25[OH]D) level has recently been reported to be an independent predictor of sustained virologic response (SVR) to treatment with pegylated interferon (PEG-IFN) plus ribavirin (RBV) for chronic hepatitis C virus (HCV) infection. However, studies have yielded inconsistent results. Thus, we conducted a systematic review and meta-analysis to clarify any association between baseline 25(OH)D level and SVR in HCV therapy.

METHODS

Two reviewers searched four electronic databases (Medline, Embase, PubMed, and Cochrane trials register) and relevant international conference proceedings up to March 2014 for studies treating chronic HCV infection with PEG-IFN plus RBV where baseline 25(OH)D level was tested. Studies involving patients with HIV co-infection, previous liver transplantation or those receiving vitamin D supplementation were excluded. The mean baseline 25(OH)D level was compared between those who achieved and those who failed to achieve SVR. Pooled standard difference in mean 25(OH)D level, odds ratios (OR) and 95% confidence intervals (CI) were calculated with the Comprehensive Meta-Analysis software (version 2.0) using a random effects model.

RESULTS

11 studies comprising 2605 patients were included in the meta-analysis. There was no significant association between the baseline mean 25(OH)D level and SVR (OR 1.44, 95% CI 0.92-2.26; p=0.11), either in patients infected with genotypes 1/4/5 (OR 1.48, 95% CI 0.94-2.34; p=0.09) or genotypes 2/3 (OR 1.51, 95% CI 0.26-8.87; p=0.65).

CONCLUSIONS

The baseline 25(OH)D level is not associated with SVR to PEG-IFN plus RBV therapy in chronic HCV infection, regardless of genotype. Any effect of vitamin D supplementation on SVR is yet to be definitively determined.

Transient Elastography in the Evaluation of Cystic Fibrosis-Associated Liver Disease: Systematic Review and Meta-analysis

Background and aims

Complications of cystic fibrosis-associated liver disease (CFLD) are a leading nonpulmonary cause of death. Transient elastography (TE) has recently been investigated to detect CFLD. This study reviews the current literature for TE in the detection CFLD. A meta-analysis was performed to determine the ideal liver stiffness measurement (LSM) cutoff.

Methods

PubMed, Medline, EMBASE and Web of Science were searched from inception until April 2016 for publications involving the detection of CFLD with TE. Data were extracted using a fixed protocol (a priori design) including study design, population characteristics, probe size and AST Platelet Ratio Index (APRI).

Results

Diagnostic properties were summarized from six studies of 605 patients. Cutoff for LSM was determined using pooled data submitted by authors. The cutoff for LSM and APRI were ≥5.95 kPa and ≥0.329 respectively, yielding a sensitivity, specificity and area under receiver operator characteristic of 55%, 87%, 0.76, 52%, 93% and 0.84 for LSM and APRI, respectively. When LSM ≥5.95 kPa and APRI ≥0.329, the sensitivity, specificity, positive predictive value and negative predictive value were 43%, 99%, 92% and 87% with a diagnostic odds ratio of 74.9. A bivariate metaregression model showed that pediatric specific cutoffs for liver stiffness and APRI may not be necessary.

Conclusion

Individually, LSM and APRI have poor sensitivity but good specificity for detecting CFLD. They are most useful when combined. We propose that patients with LSM ≥5.95 kPa and APRI ≥0.329 be investigated thoroughly for the presence of cystic fibrosis-associated liver disease.

Comparison of three cut-offs to diagnose clinically significant portal hypertension by liver stiffness in chronic viral liver diseases: a meta-analysis

BACKGROUND

Transient elastography-based liver stiffness value (TE-LSV) has been investigated for assessing clinically significant portal hypertension (CSPH). The aetiology of CSPH is an important factor determining TE-LSV. There is insufficient evidence for selecting cut-off values.

AIMS

This study performed a meta-analysis to compare the three most widely used cut-off values (around 13.6 kPa, 18 kPa and 22kPa) of TE-LSV for the diagnosis of CSPH in patients with chronic viral liver disease.

METHODS

The PubMed, Ovid, Web of Science and Cochrane Library databases were searched. Diagnostic data for cut-off values around 13.6 kPa, 18 kPa and 22 kPa in each included study were extracted. The bivariate model was performed to estimate pooled sensitivity, specificity, positive likelihood ratio (LR+) and negative likelihood ratio (LR-).

RESULTS

Eleven studies assessing 910 patients were included in this meta-analysis. Pooled sensitivities of cut-off values around 13.6 kPa, 18 kPa and 22 kPa were 0.96 (95% CI 0.93-0.97), 0.85 (0.81-0.89) and 0.74 (0.66-0.80), respectively; pooled specificities were 0.60 (0.47-0.75), 0.80 (0.71-0.87) and 0.94 (0.86-0.97), respectively. Pooled LR+ values were 2.4 (1.6-3.7), 4.4 (2.9-6.8) and 11.5 (5.5-23.5) for cut-off values around 13.6 kPa, 18 kPa and 22 kPa, respectively, for pooled LR- values of 0.07 (0.04-0.13), 0.17 (0.12-0.25) and 0.28 (0.22-0.36), respectively.

CONCLUSION

Cut-off values around 13.6 kPa (high sensitivity) and 22 kPa (high specificity) could be used as screening and confirmation tools, respectively, in the diagnosis of CSPH. Overall, the cut-off value around 22 kPa showed the best performance.

KEY POINTS

Transient elastography-based liver stiffness could be used to diagnose portal hypertension. Comparison of certain cut-off values would provide more information for clinical decision-making. Cut-off around 13.6 kPa was able to exclude clinically significant portal hypertension (CSPH) effectively. Cut-off around 22 kPa was able to confirm CSPH effectively.

Infection with wild-type mumps virus in army recruits temporally associated with MMR vaccine

Four cases of mumps were reported among 180 army recruits who had received MMR vaccine 16 days earlier. Mumps serology, salivary mumps IgM and PCR tests for the SH gene were performed on the 4 cases and on 5 control recruits who remained well. PCR products were sequenced and the sequences compared to those of wild type and vaccine strains of mumps. Further salivary mumps IgM tests were performed on the remaining 171 recruits. Mumps infection was confirmed in the 4 cases but not in the 5 controls. The controls had serological evidence of prior immunity. The SH gene sequence found in the 4 cases was wild type. Saliva tests identified 2 additional recruits with mumps IgM, one of whom had presented with suspected mumps 2 days before the MMR vaccine was given. Thus 6 (5 symptomatic and 1 asymptomatic) cases of mumps in army recruits recently receiving MMR vaccine were not due to the vaccine but to coincidental infection with wild-type mumps virus. The probable index case was revealed by salivary mumps IgM tests. This study highlights the importance of appropriate investigation of illness associated with MMR vaccination.

Reliability of Transient Elastography-Based Liver Stiffness for Diagnosing Portal Hypertension in Patients with Alcoholic Liver Disease: A Diagnostic Meta-Analysis with Specific Cut-Off Values

BACKGROUND

 Transient elastography-based liver stiffness value (TE-LSV) has been studied for the diagnosis of portal hypertension. Liver stiffness is influenced by the disease etiology. We aimed to perform a meta-analysis to determine the performance of TE-LSV for diagnosing portal hypertension in patients with alcoholic liver disease (ALD).

METHODS

 We searched PubMed, Web of Science, Ovid and Cochrane library. A bivariate model was used to compute sensitivity and specificity. A random effects model was used to pool diagnostic odds ratios.

RESULTS

 9 studies with 679 patients were included. The pooled sensitivity and specificity based on a cut-off value around 21.8 kPa for clinically significant portal hypertension (CSPH) were 0.89 (95 % confidence interval (CI), 0.83-0.93) and 0.71(95 % CI, 0.64-0.78), respectively. For severe portal hypertension (SPH), the pooled sensitivity and specificity for a cut-off value around 29.1 kPa were 0.88 (95 % CI, 0.83-0.92) and 0.74 (95 % CI, 0.67-0.81), respectively.

CONCLUSION

 TE-LSV showed good performance for diagnosing portal hypertension in patients with ALD. The optimal cut-off value for CSPH and SPH was around 21.8 kPa and 29.1 kPa, respectively, and these two cut-off values showed good sensitivity and modest specificity. The etiology should be clear before using TE-LSV for portal hypertension.

Interleukin-28B rs12979860 C allele: Protective against advanced fibrosis in chronic hepatitis C genotype 1 infection

Background and Aim: While genetic polymorphisms upstream of the interleukin-28B(IL28B) gene are associated with necroinflammatory activity grade in chronic hepatitis C virus genotype 1 (HCV-1) infection, any association with fibrosis is less definitive. Pretreatment liver biopsies in a cohort of treatment-naïve patients with HCV-1 were analyzed to evaluate associations between liver histology, and the rs12979860 and rs8099917 IL28B single nucleotide polymorphisms.Methods: Two hundred sixty-six patients with HCV-1 infection and pretreatment liver biopsy were tested for the rs12979860 and rs8099917 single nucleotide polymorphisms.Predictors of advanced fibrosis (METAVIR F3/4) and high activity grade (A2/3) were identified using multivariable logistic regression analysis.Results: Forty-four patients (16.5%) had advanced fibrosis and 141 patients (53.0%) high activity grade. Prevalence of rs12979860 IL28B genotype was: CC 45.7%, CT 42.7%, and TT 11.6%. Prevalence of advanced fibrosis was lower in those with IL28B CC genotype compared with those without (11.0% vs 21.3%; P = 0.03), with an increasing number of Talleles associated with a higher frequency of advanced fibrosis: CC 11.0%, CT 18.0%, TT33.3% (P = 0.01). Predictors of advanced fibrosis on multivariate analysis were platelet count (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.97–0.99; P < 0.0001), high activity grade (OR 5.68, 95% CI% 1.86–17.32; P = 0.002), IL28B rs12979860 CC genotype(OR 0.36, 95% CI 0.14–0.93; P = 0.03), and aspartate aminotransferase (OR 1.02,95% CI 1.00–1.03; P = 0.046). No association was found between rs8099917 IL28B genotype and liver histology.Conclusions: IL28B rs12979860 CC genotype appears to be independently associated with a lower prevalence of advanced fibrosis stage in HCV-1 infection. This association warrants further evaluation.