Low serum vitamin D levels are associated with severe histological features and poor response to therapy in patients with autoimmune hepatitis

Natural history and long-term management of autoimmune hepatitis

INTRODUCTION

Autoimmune hepatitis (AIH) is a relatively infrequent and complex liver disease characterized by acute or chronic inflammation, interface hepatitis in histology examination, elevation of immunoglobulin G (IgG), production of autoantibodies, and is often responsive to immunosuppression. The incidence of AIH has been increasing worldwide, affecting people of all ages and sexes. AIH represents a diagnostic challenge because of its heterogeneous presentation and the lack of pathognomonic findings. Even when treated, AIH can remain a progressive disease. In this review, we present recent data on the natural history of AIH and the developing evidence on the management of patients with AIH.

AREAS COVERED

This review outlines the clinical presentation, risk factors linked to poorer clinical outcomes, the diagnostic algorithm, and the current management strategies for individuals living with AIH.

EXPERT OPINION

AIH remains a clinical challenge, and new tools for better diagnosis and stratification of risk are needed. In addition, better treatments are needed as a complete response is achieved in less than 60% of cases, and intolerance to first-line treatment is frequent. The use of biological treatment in AIH seems to improve the response rate and minimize the risk of side effects of current medication in this increasingly prevalent disease.

British Society of Gastroenterology guidelines for diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease which, if untreated, often leads to cirrhosis, liver failure and death. The last British Society of Gastroenterology (BSG) guideline for the management of AIH was published in 2011. Since then, our understanding of AIH has advanced in many areas. This update to the previous guideline was commissioned by the BSG and developed by a multidisciplinary group. The aim of this guideline is to review and summarise the current evidence, in order to inform and guide diagnosis and management of patients with AIH and its variant syndromes. The main focus is on AIH in adults, but the guidelines should also be relevant to older children and adolescents.

Serum vitamins and homocysteine levels in autoimmune liver disease: A systematic review and meta-analysis

OBJECTIVE

Vitamins and homocysteine (Hcy) are involved in liver metabolism and related to the pathogenesis of autoimmune liver disease (AILD), but consensus is lacking. This study aims to systematically summarize relevant evidence to clarify the association of serum vitamins and Hcy levels with AILD.

METHODS

The English and Chinese literature was searched until August 29, 2023. Studies were included if they were observational studies of investigating serum vitamins and Hcy levels in patients with AILD and their healthy comparisons. Quality assessment was performed by using the Newcastle-Ottawa Scale, and a meta-analysis was conducted using ReviewManager 5.3. The protocol was registered in the international prospective register of systematic reviews (PROSPERO), with registration number CRD42023455367.

RESULTS

A total of 25 case-control studies comprising 3487 patients (1673 patients and 1814 healthy controls) were included for analysis. There were 548 autoimmune hepatitis (AIH) cases, 1106 primary biliary cholangitis (PBC) cases, and 19 primary sclerosing cholangitis (PSC) cases. We found that serum A and E were decreased in both AIH and PBC/PSC; but vitamin C was reduced only in patients with PBC, not AIH. In addition, decreased content of 25(OH)D3 was found in both AIH and PBC. However, levels of 25(OH)D did not differ between the patients and controls, and were independent of disease types and the country. Only one study that met the inclusion criteria reported vitamin B6, B9, B12, and Hcy changes, and found that vitamin B6 and B9 were significantly decreased in patients with PBC, while serum vitamin B12 and Hcy levels were significantly elevated in them. One eligible study each confirmed a reduction in plasma vitamin K1 and 1,25(OH)2D3 in patients with PBC.

CONCLUSION

Most vitamins are deficient in AILD, so appropriate vitamin supplementation should be necessary. Further studies with larger sample sizes are needed to validate these findings.

Calcitriol Protects against Acetaminophen-Induced Hepatotoxicity in Mice

Acetaminophen (APAP) overdose is one of the major causes of acute liver failure. Severe liver inflammation and the production of oxidative stress occur due to toxic APAP metabolites and glutathione depletion. Growing evidence has proved that vitamin D (VD) exerts anti-inflammatory and antioxidative functions. Our objective was to explore the protective role of calcitriol (VD3) in acute APAP-induced liver injury. Methods: Adult male mice were randomized into three groups; control (n = 8), APAP (n = 8), and VD3 group (n = 8). All mice, except controls, received oral administration of APAP (400 mg/kg) and were sacrificed 24 h later. In the VD3 group, calcitriol (10 µg/kg) was injected intraperitoneally 24 h before and after exposure to APAP. Blood samples were collected to assess serum aminotransferase and inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)]. Liver tissues were analyzed for hepatic glutathione (GSH), malondialdehyde (MDA), and histopathology. Results: APAP administration significantly increased serum aminotransferase, inflammatory cytokines, and induced cellular inflammation and necrosis. APAP also depleted hepatic GSH and elevated oxidative stress, as indicated by high MDA levels. In the APAP group, 25% of the mice (two out of eight) died, while no deaths occurred in the VD3 group. Treatment with calcitriol significantly reduced serum aminotransferase, TNF-α, and IL-6 levels in the VD3 group compared to the APAP group. Additionally, VD3 effectively restored GSH reserves, reduced lipid peroxidation, and attenuated hepatotoxicity. Conclusions: These findings demonstrate that VD3 prevents APAP-induced acute liver injury and reduces mortality in mice through its anti-inflammatory and antioxidative activity. Thus, VD3 might be a novel treatment strategy for APAP-induced hepatotoxicity.

Detection of Novel Biomarkers in Pediatric Autoimmune Hepatitis by Proteomic Profiling

Autoimmune hepatitis (AIH) is characterized by immune-mediated hepatocyte injury resulting in the destruction of liver cells, causing inflammation, liver failure, and fibrosis. Pediatric (AIH) is an autoimmune inflammatory disease that usually requires immunosuppression for an extended period. Frequent relapses after treatment discontinuation demonstrate that current therapies do not control intrahepatic immune processes. This study describes targeted proteomic profiling data in patients with AIH and controls. A total of 92 inflammatory and 92 cardiometabolic plasma markers were assessed for (i) pediatric AIH versus controls, (ii) AIH type 1 versus type 2, (iii) AIH and AIH-autoimmune sclerosing cholangitis overlapping syndrome and (iv) correlations with circulating vitamin D levels in AIH. A total of 16 proteins showed a nominally significant differential abundance in pediatric patients with AIH compared to controls. No clustering of AIH subphenotypes based on all protein data was observed, and no significant correlation of vitamin D levels was observed for the identified proteins. The proteins that showed variable expression include CA1, CA3, GAS6, FCGR2A, 4E-BP1 and CCL19, which may serve as potential biomarkers for patients with AIH. CX3CL1, CXCL10, CCL23, CSF1 and CCL19 showed homology to one another and may be coexpressed in AIH. CXCL10 seems to be the central intermediary link for the listed proteins. These proteins were involved in relevant mechanistic pathways for liver diseases and immune processes in AIH pathogenesis. This is the first report on the proteomic profile of pediatric AIH. The identified markers could potentially lead to new diagnostic and therapeutic tools. Nevertheless, considering the complex pathogenesis of AIH, more extensive studies are warranted to replicate and validate the present study's findings.

Autoimmune Hepatitis and Fibrosis

Autoimmune hepatitis (AIH) is a chronic immune-inflammatory disease of the liver, generally considered a rare condition. The clinical manifestation is extremely varied and can range from paucisymptomatic forms to severe hepatitis. Chronic liver damage causes activation of hepatic and inflammatory cells leading to inflammation and oxidative stress through the production of mediators. This results in increased collagen production and extracellular matrix deposition leading to fibrosis and even cirrhosis. The gold standard for the diagnosis of fibrosis is liver biopsy; however, there are serum biomarkers, scoring systems, and radiological methods useful for diagnosis and staging. The goal of AIH treatment is to suppress fibrotic and inflammatory activities in the liver to prevent disease progression and achieve complete remission. Therapy involves the use of classic steroidal anti-inflammatory drugs and immunosuppressants, but in recent years scientific research has focused on several new alternative drugs for AIH that will be discussed in the review.

Open challenges in the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its etiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimization of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outlined the clinical characteristics, etiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provided evidence underlying the evolution of diagnostic and clinical management protocols.

Prognostic Significance of Severe Vitamin D Deficiency in Patients with Primary Sclerosing Cholangitis

Vitamin D deficiency has been linked with adverse events in various liver diseases. The present study aimed to recognize the association between severe vitamin D deficiency and disease progression, hepatobiliary malignancies, liver-related mortality, and the need for liver transplantation in primary sclerosing cholangitis (PSC). Patients with a diagnosis of PSC (n = 354), followed by the autoimmune liver disease clinic at the University of Alberta, were included. Patients with vitamin D levels < 25 nmol/L were defined as severely deficient. Univariate and multivariate analyses were conducted using the Cox proportional hazards regression models. The mean vitamin D level was 59 ± 2 nmol/L, and 63 patients (18%) had a severe vitamin D deficiency. Patients with a severe vitamin D deficiency were 2.5 times more likely to experience hepatobiliary malignancies (HR 2.55, 95% CI, 1.02-6.40, p = 0.046). A severe vitamin D deficiency at diagnosis (HR 1.82, 95% CI, 1.05-3.15, p = 0.03) and persistent deficiencies over time (HR 2.26, 95% CI, 1.17-4.37, p = 0.02) were independently associated with a higher risk of poor clinical liver outcomes. A severe vitamin D deficiency at diagnosis and persistent deficiency at longitudinal assessments were associated with liver-related mortality or the need for liver transplantation.

Noninvasive biomarkers for the diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare disease of unclear etiology characterized by loss of self-tolerance that can lead to liver injury, cirrhosis, and acute liver failure. First-line treatment consists of systemic corticosteroids, or budesonide, and azathioprine, to which most patients are initially responsive, although predictors of response are lacking. Relapses are very common, correlate with histological activity despite normal serum transaminases, and increase hepatic fibrosis. Furthermore, current regimens lead to adverse effects and reduced quality of life, whereas medication titration is imprecise. Biomarkers that can predict the clinical course of disease, identify patients at elevated risk for relapse, and improve monitoring and medication dosing beyond current practice would have high clinical value. Herein, we review novel candidate biomarkers in adult and pediatric AIH based on prespecified criteria, including gene expression profiles, proteins, metabolites, and immune cell phenotypes in different stages of AIH. We also discuss biomarkers relevant to AIH from other immune diseases. We conclude with proposed future directions in which biomarker implementation into clinical practice could lead to advances in personalized therapeutic management of AIH.

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.

Role of Vitamin D in Liver Disease and Complications of Advanced Chronic Liver Disease

Vitamin D is a crucial nutrient with many pleiotropic effects on health and various chronic diseases. The purpose of this review is to provide a detailed report on the pathophysiological mechanisms underlying vitamin D deficiency in patients with chronic liver disease, addressing the different liver etiologies and the condition of advanced chronic liver disease (cirrhosis) with related complications. To date, patients with liver disease, regardless of underlying etiology, have been shown to have reduced levels of vitamin D. There is also evidence of the predictive role of vitamin D values in complications and progression of advanced disease. However, specific indications of vitamin D supplementation are not conclusive concerning what is already recommended in the general population. Future studies should make an effort to unify and validate the role of vitamin D supplementation in chronic liver disease.

Vitamin D-VDR Novel Anti-Inflammatory Molecules-New Insights into Their Effects on Liver Diseases

There is consistent evidence that vitamin D deficiency is strongly associated with liver dysfunction, disease severity, and poor prognosis in patients with liver disease. Vitamin D and its receptor (VDR) contribute to the regulation of innate and adaptive immune responses. The presence of genetic variants of vitamin D- and VDR-associated genes has been associated with liver disease progression. In our recent work, we summarized the progress in understanding the molecular mechanisms involved in vitamin D-VDR signaling and discussed the functional significance of VDR signaling in specific cell populations in liver disease. The current review focuses on the complex interaction between immune and liver cells in the maintenance of liver homeostasis and the development of liver injury, the interplay of vitamin D and VDR in the development and outcome of liver disease, the role of vitamin D- and VDR-associated genetic variants in modulating the occurrence and severity of liver disease, and the therapeutic value of vitamin D supplementation in various liver diseases. The association of the vitamin D-VDR complex with liver dysfunction shows great potential for clinical application and supports its use as a prognostic index and diagnostic tool.

Serum Biomarkers for Autoimmune Hepatitis Type 1: the Case for CD48 and a Review of the Literature

In autoimmune hepatitis (AIH), the persisting inflammation contributes to fibrosis progression, for which conventional biochemical markers manifest relatively unsatisfactory prediction. Herein, we assessed the value of serum CD48 (sCD48) as an indicator for inflammation and fibrosis in AIH type 1. The levels of sCD48 were detected first in an exploratory cohort using ELISA. In this cohort, compared with healthy controls (4.90 ng/mL, P < 0.0001), primary biliary cholangitis (7.32 ng/mL, P < 0.0001), and non-alcoholic fatty liver disease (7.76 ng/mL, P < 0.0001), sCD48 levels were elevated in AIH (12.81 ng/mL) and correlated with histological inflammation and fibrosis. Further using multivariate logistic regression analysis, sCD48 was identified as an independent predictor for both significant inflammation (G3-4) and advanced fibrosis (S3-4). Two predictive scores, based on sCD48, were constructed for diagnosing significant inflammation and advanced fibrosis (sCD48-AIH-SI and sCD48-AIH-AF, respectively). Using these data as a premise, predictive abilities were subsequently evaluated and verified in a validation cohort. In the exploratory cohort, the area under the receiver operating characteristic curve of sCD48 and sCD48-AIH-SI, for significant inflammation, were 0.748 and 0.813, respectively. Besides, during treatment follow-up, sCD48 levels gradually decreased from immunosuppression initiation to re-evaluation biopsy, in parallel with aspartate transaminase, total sera IgG, and fibrosis-4 score. For AIH patients in a re-evaluation biopsy cohort, sCD48 could predict significant fibrosis (S2-4). Further using immunohistochemistry, hepatic CD48 expression was elevated in AIH patients and decreased after treatment. In conclusion, sCD48 and sCD48-based predictive scores predict histological inflammation and fibrosis in AIH-1. Detecting sCD48 might help in the clinical management of AIH.

Serum 25-hydroxyvitamin D and C-reactive protein and plasma von Willebrand concentrations in 23 dogs with chronic hepatopathies

BACKGROUND

Serum concentrations of 25-hydroxyvitamin D (25(OH)VD) and C-reactive protein (CRP) and von Willebrand's factor (vWF) concentration correlate with histopathologic disease grade and stage in chronic inflammatory and fibrotic hepatopathies (CH) in humans.

OBJECTIVES

To evaluate serum 25(OH)VD and serum CRP concentrations and plasma vWF concentration and determine if they correlate with histopathologic and biochemical variables in dog with CH.

ANIMALS

Twenty-three client-owned dogs with a histopathologic diagnosis of CH were prospectively enrolled.

METHODS

Blood samples were collected before liver biopsy. Correlations between biomarkers and clinical pathological and histopathologic variables were evaluated using Pearson's or Spearman's test.

RESULTS

Serum 25(OH)VD concentration (median, 213 nmol/L; range, 42-527 nmol/L) was negatively correlated with serum aspartate aminotransferase activity (AST; rho = -0.59, P < .01), polymorphonuclear neutrophil count (PMN; r = -0.46, P < .05), and positively correlated with serum albumin concentration (r = 0.69, P < .001). Serum CRP concentration (median, 7.4 μg/L; range, 1-44.9 μg/L) was positively correlated with overall histopathologic necroinflammatory activity (r = 0.78, P < .001) and fibrosis score (rho = 0.49, P < .05). Plasma vWF concentration (median, 73.3%; range, 15-141%) was positively correlated with fibrosis score (r = 0.53, P < .05) and prothrombin time (rho = 0.67, P < .01), and negatively correlated with serum albumin concentration (r = -0.73, P < .001).

CONCLUSION AND CLINICAL IMPORTANCE

In dogs with CH, serum 25(OH)VD concentration was negatively correlated with disease activity, whereas serum CRP concentration and plasma vWF concentration were positively correlated with histopathologic grade and stage. Our results provide preliminary evidence that these biomarkers may be useful to assess grade and stage of CH in dogs in the absence of liver biopsy.

Vitamin D Is Associated with Clinical Outcomes in Patients with Primary Biliary Cholangitis

Vitamin D (VD) deficiency has been associated with clinical outcomes in patients with chronic liver disease. This study aims to identify the prevalence of VD deficiency in patients with primary biliary cholangitis (PBC) and its association with treatment response to ursodeoxycholic acid (UDCA), cirrhosis development, and liver-related events (mortality and liver transplantation). Two hundred and fifty-five patients with PBC diagnosis were evaluated. Patients with VD levels below 50 nmol/L were defined as deficient. Treatment response to UDCA was defined according to the Toronto criteria. Independent risk factors were identified using binary logistic and Cox regression analysis. The mean level of serum VD was 77 ± 39 nmol/L, and 64 patients (25%) were VD deficient. Incomplete response to UDCA was more prevalent in VD-deficient patients compared to their counterparts (45% vs. 22%; p < 0.001). The risk of cirrhosis development (hazard ratio (HR) 1.93; 95% confidence interval (CI) 1.17–3.19, p = 0.01) and liver-related mortality or need for liver transplantation (HR 3.33, 95% CI, 1.57–7.07, p = 0.002) was higher in VD-deficient patients after adjusting for confounders. Vitamin D deficiency is frequent in patients with PBC and is associated with incomplete response to UDCA, cirrhosis development, and liver-related mortality or need for liver transplantation.

Vitamin D supplementation for autoimmune hepatitis: A need for further investigation

Autoimmune hepatitis is a chronic liver disease harboring an autoimmune basis and progressive character. Despite still obscurity in etiology and pathogenesis, some evidence supports the importance of sustaining the immune system. Vitamin D is a lipo-soluble vitamin, which has been identified as decreased in our body. It is often due to the daily habit change and decrease of individual sun exposure due to the increase of the ultraviolet-induced potential melanocytic transformation. Here, we emphasize the importance of vitamin D supplementation in patients affected with liver disease.

Course of vitamin D levels before and after liver transplantation in pediatric patients

BACKGROUND

25-hydroxy VD insufficiency is known in children undergoing LT but the serial post-transplant VD course and supplementation modalities in the peri-transplant period are lacking. We aimed to determine the pre-VD status and the post-transplant VD status course following VD supplementation and to elucidate its relationship with post-transplant outcome parameters such as infection and survival.

METHODS

Pre- and post-VD levels were monitored in parallel with interventions to adjust VD levels in LT patients. VD status was categorized as circulating levels <30-21 ng/ml (insufficiency), 20-10 ng/ml (deficiency), and <10 ng/ml (severe deficiency). Patients received stoss (300000IU) VD3 within the pretransplant period if serum levels were <20 ng/ml.

RESULTS

135 transplanted children were included. The age at LT was 22 months (IQR: 8-60). The pretransplant median VD level was 14 ng/ml. Despite stoss dose, post-transplant median VD level was 1.8 ng/ml (day one), 4 ng/ml (week one), 19 ng/ml (month one), 33 ng/ml (month three), 38 ng/ml (months 6-12), and 40 ng/ml (month 24). After 6 months, VD status reached >30 ng/ml in 98% of patients. Only at pre-LT, higher infection rate (18.7%) in the severe VD deficiency group was observed compared to the VD deficiency group (2.9%, p = .04). Survival was not affected by serum VD levels.

CONCLUSION

VD levels fell substantially after LT but are rectifiable by stoss dose, which was well tolerated. Only the infection rate was associated with the VD status.

Genetic aspects of adult and pediatric autoimmune hepatitis: A concise review

Autoimmune Hepatitis (AIH) is a heterogenous, mostly chronic liver disease that affects people of all age groups, women more often than men. The aim of therapy is to prevent cirrhosis, as it mainly accounts for liver-related mortality in patients with AIH. Rates of remission are high in patients with AIH, but life-long immunosuppressive therapy is required. AIH is hypothesized to originate from immunologic reactivity targeted against mostly unknown self-antigens, potentially triggered by viral infections among other factors. While AIH does not follow a Mendelian inheritance pattern, part of the risk of developing AIH or worse disease course, is attributed to specific genetic risk factors. Major associations for the risk of development of AIH were found for HLA-DRB1*03:01 and HLA-DRB1*04:01 in adult AIH in the only genome-wide association study on AIH. However, other potential risk loci in SH2B3, CARD10 and KIR genes were described. This review covers the current knowledge on genetic risk factors in adult and pediatric AIH.

Genetic risk factors for autoimmune hepatitis: implications for phenotypic heterogeneity and biomarkers for drug response

Autoimmune hepatitis (AIH) is a rare chronic progressive liver disease with autoimmune features. It mainly affects middle-aged women. AIH is occasionally complicated with liver cirrhosis that worsens the prognosis. Genetic and environmental factors are involved in the pathogenesis of AIH. Genetic studies of other diseases have been revealing of pathogenesis and drug efficacy. In this review, we summarize the genetic risk factors for AIH, including human leukocyte antigen (HLA) and non-HLA genes. A genome-wide association study (GWAS) on European AIH revealed the strongest associations to be with single nucleotide variants (SNVs) in HLA. Predisposing alleles for AIH were DRB1*03:01 and DRB1*04:01 in Europeans; DRB1*04:04, DRB1*04:05, and DRB1*13:01 in Latin Americans; and DRB1*04:01 and DRB1*04:05 in Japanese. Other risk SNVs in non-HLA genes for AIH were found by a candidate gene approach, but several SNVs were confirmed in replication studies. Some genetic factors of AIH overlapped with those of other autoimmune diseases. Larger-scale GWASs of other ethnic groups are required. The results of genetic studies might provide an explanation for the phenotypic heterogeneity of AIH and biomarkers for drug responses.

Recent updates on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immunoinflammatory chronic liver disease with dynamic and rather heterogeneous disease manifestations. A trend of increasing prevalence of AIH has been observed worldwide, along with a relative increase in the percentage of male patients. AIH is characterized and diagnosed based on serum biochemistry and liver histology: elevated aminotransferases and serum immunoglobulin G (IgG), the presence of serum anti-nuclear antibody or anti-smooth muscle antibody, and interface lympho-plasmacytic hepatitis. Clinical manifestations differ among disease subtypes with distinct time-frames, i.e., AIH with a chronic insidious onset, and acute-onset AIH (the diagnosis of which is often challenging due to the lack of typical serum findings). The absence of disease-specific biomarkers or histological findings may expand the disease phenotype into drug-induced AIH-like liver injury. Corticosteroids and azathioprine are recommended first-line treatments for AIH. The complete normalization of aminotransferases and serum IgG is an essential treatment response to ensure long-term overall survival. An incomplete response or intolerance to these drugs is considered an indication for second-line treatment, especially with mycophenolate mofetil. Life-long maintenance treatment is required for the majority of patients, but the few who achieve prolonged and stringent biochemical remission with lower alanine aminotransferase and IgG within the normal range may be able to discontinue the medications. In the future, the quality of life of AIH patients should be managed by personalized medicine, including the appropriate selection and dosing of first-line therapy and perhaps alternating with potential therapeutics, and the prediction of the success of treatment withdrawal.

Genotype-guided dietary supplementation in precision nutrition

Achieving adequate micronutrient status, while avoiding deficiencies, represents a challenge for people globally. Consequently, many individuals resort to oral nutrient supplementation (ONS) in order to correct suboptimal dietary intakes. Advances in the fields of nutrigenetics and nutritional genomics have identified differences in response to micronutrient supplementation according to genetic makeup, adding dietary supplement use to the clinician's toolkit in the precision nutrition era. This review focuses on published evidence linking genetic variants to the responses associated with some of the most popular dietary supplements. With an increasing number of health professionals becoming involved in the prescription of ONS, identifying and matching individuals to the appropriate dietary supplement according to their genotype is important for achieving optimal health benefits and micronutrient equilibrium, while reducing the adverse events and financial costs often associated with excessive ONS.

Association of serum 25-hydroxyvitamin D levels with severe necroinflammatory activity and inflammatory cytokine production in type I autoimmune hepatitis

25-Hydroxyvitamin D [25(OH)D] has been reported to be associated with several chronic liver diseases. The relationship between 25(OH)D and autoimmune hepatitis (AIH) pathogenesis is incompletely understood. We investigated the association of serum total and free 25(OH)D levels with necroinflammatory activity and cytokine levels in 66 patients with AIH diagnosed in our hospital. The median age at AIH diagnosis was 57 years, and the male:female ratio was 7:59. The median serum total 25(OH)D level in therapy-naïve patients with AIH was 14.2 ng/mL (interquartile range [IQR], 11.4–17.9 ng/mL). Of the 66 patients with AIH, 36 had serum total 25(OH)D levels of < 15 ng/mL and were considered to have vitamin D deficiency, and 30 had serum total 25(OH)D levels of ≥ 15 ng/mL. Patients with acute-onset AIH had significantly lower serum total 25(OH)D levels than those with chronic-onset AIH. In particular, serum total 25(OH)D levels were significantly lower in patients with severe forms of AIH. Furthermore, the serum total 25(OH)D level was positively correlated with the serum albumin level and prothrombin time and negatively correlated with the serum total bilirubin level and necroinflammatory activity in AIH. Multivariate logistic regression analysis showed that the serum total 25(OH)D level was an independent factor for severe necroinflammatory activity. Interestingly, AIH patients with serum total 25(OH)D levels of < 15 ng/mL had higher levels of inflammatory cytokines such as interferon-γ and interleukin-33. Free 25(OH)D levels were correlated with total 25(OH)D levels, and the percentage of free 25(OH)D was significantly associated with necroinflammatory activity. In conclusion, 25(OH)D deficiency may play an important role in predicting AIH severity via inflammatory cytokine production.

Changes in hepatic fibrosis and vitamin D levels after viral hepatitis C eradication using direct-acting antiviral therapy

BACKGROUND

Vitamin D (VD) is important in hepatic fibrogenesis in animal models and human studies. VD deficiency is associated with liver fibrosis progression. Metabolic dysfunction of the liver, as an intermediate organ for VD metabolism, contributes partly to this deficiency. We hypothesized that improving hepatic fibrosis and inflammation in chronic hepatitis C (CHC) patients after eradication with direct-acting antivirals (DAA) would increase 25-hydroxyVD [25(OH)VD] levels.

METHODS

Eighty CHC patients (17 chronic hepatitis, and 63 cirrhosis) were enrolled. Baseline characteristics, hepatitis C viral load (VL), genotypes, liver enzymes and liver stiffness measurements (LSM) were assessed at baseline. Blood samples for 25(OH)VD and the procollagen type III N-terminal peptide (P3NP) were collected at baseline, 24 and 48 weeks. LSMs were re-evaluated at 48 weeks. Serum 25(OH)VD levels < 30 ng/mL were defined as VD insufficiency/deficiency. Paired t-tests were used for statistical analyses.

RESULTS

Among 80 patients, the mean age was 57.7 ± 10.5 years, and 52.5% were men. The mean VL was 6.1 ± 0.7 logIU/mL with genotype 1 predominance (55%). All patients achieved sustained virological response. The alanine aminotransferase levels decreased from 79.9 ± 53.3 U/L at baseline to 25.7 ± 17.2 and 22.3 ± 11.0 U/L at 24 and 48 weeks, respectively (p < 0.001). The mean LSM decreased from 19.2 ± 15.3 to 11.7 ± 8.0 kPa at 48 weeks (p < 0.001). The P3NP levels decreased from 43.6 ± 22.0 ng/mL before treatment to 35.7 ± 21.1 and 29.4 ± 15.0 ng/mL at 24 and 48 weeks, respectively (p < 0.001). The proportions of VD insufficiency/deficiency were 72.5%, 91.3%, and 86.5% at baseline, 24 and 48 weeks, respectively. The 25(OH)VD levels decreased from 26.3 ± 10.7 ng/mL at baseline to 20.8 ± 8.1 and 20.8 ± 8.5 ng/mL at 24 and 48 weeks, respectively (p < 0.001).

CONCLUSIONS

Curative treatment with DAA attenuated the liver stiffness and inflammation but did not improve VD levels. Over 80% of patients remained VD insufficient/deficient. Whether VD replacement during and after DAA therapy can improve hepatic fibrosis remains unclear. Trial registration The Thai Clinical Trial Registry as TCTR20161025001 (31 October 2016). http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=2136 .

The relation of 25-hydroxy vitamin D concentrations to liver histopathology, seasonality and baseline characteristics in chronic hepatitis C virus genotype 2 or 3 infection

Background and objectives

The hydroxylation to 25-hydroxy vitamin D (25(OH)D) occurs in the liver and the impact of liver disease on vitamin D is unclear. This study evaluated the relationship between vitamin D concentrations and hepatic histopathology, seasonality and patient characteristics in well-characterized patients having undergone a liver biopsy.

Method

25(OH)D was measured post-hoc in pre-treatment serum from 331 North European patients with chronic HCV genotype 2 or 3 infection (NORDynamIC study). Liver biopsies were scored for fibrosis and inflammation according to the Ishak protocol, and graded for steatosis. Non-invasive markers of hepatic fibrosis as well as baseline viral and host characteristics, including genetic polymorphisms rs2228570, rs7975232, and rs10877012 were also evaluated.

Results

Mean 25(OH)D concentration was 59 ±23 nmol/L, with 41% having values <50 nmol/L and 6% were <30 nmol/L. 25(OH)D correlated with fibrosis (r = -0.10, p ≤0.05) in univariate but not in multivariate analyses. No association was observed between 25(OH)D and hepatic inflammation, but with steatosis in HCV genotype 2 infected patients. None of the genetic polymorphisms impacted on 25(OH)D levels or fibrosis. 25(OH)D levels were significantly inversely correlated to BMI (r = -0.19, p = 0.001), and was also associated with season and non-Caucasian ethnicity.

Conclusion

Fibrosis was not independently associated with 25(OH)D concentration and no association was seen with hepatic inflammation, but HCV genotype 2 infected patients with moderate-to-severe steatosis had lower 25(OH)D levels compared to those without steatosis. A high percentage had potential risk of 25(OH)D deficiency, and BMI, seasonality and ethnicity were independently associated with 25(OH)D as previously reported.

Correlation of vitamin D with inflammatory factors, oxidative stress and T cell subsets in patients with autoimmune hepatitis

Correlation of vitamin D with inflammatory factors, oxidative stress and T cell subsets in patients with autoimmune hepatitis were investigated. Patients with liver diseases (n=635) treated in The Sixth People's Hospital of Qingdao City from March 2015 to January 2018 were selected, among which 80 cases diagnosed with autoimmune hepatitis were included into observation group, and 80 healthy cases were included into control group. Patients with autoimmune hepatitis were further divided into normal 25-hydroxyvitamin D [25-(OH) D] group (n=40) and abnormal 25-(OH) D group (n=40) according to the level of 25-(OH) D, and divided into normal liver function group (n=40) and abnormal liver function group (n=40). 25-(OH) D, liver function, inflammatory factors, oxidative stress level and T cell subsets were compared. In the observation group, levels of 25-(OH) D, superoxide dismutase (SOD), total antioxidant capacity, and T cell subsets were lower than those in the control group (P<0.05), while levels of total bilirubin (TBIL), indirect BIL (IBIL), direct BIL (DBIL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), inflammatory factors and malondialdehyde (MDA) were higher than those in the control group (P<0.05). In the normal 25-(OH) D group, levels of inflammatory factors and oxidative stress factor were lower than those in the abnormal 25-(OH) D group (P<0.05), while the SOD level, total antioxidant capacity and T cell subset counts were higher than those in the abnormal 25-(OH) D group (P<0.05). Moreover, the 25-(OH) D level in patients with autoimmune hepatitis was negatively correlated with hs-CRP, tumor necrosis factor-α (TNF-α), ALT and MDA, but positively correlated with CD3⁺ and CD4⁺ counts, SOD and total antioxidant capacity. Patients with autoimmune hepatitis, especially those with decreased level of vitamin D, are more prone to enhanced inflammatory and stress responses, decreased levels of T cell subsets and decline in immunity.

Pathophysiological Role and Therapeutic Implications of Vitamin D in Autoimmunity: Focus on Chronic Autoimmune Diseases

Vitamin D is a pleiotropic secosteroid yielding multiple actions in human physiology. Besides the canonical regulatory activity on bone metabolism, several non-classical actions have been described and the ability of vitamin D to partake in the regulation of the immune system is particularly interesting, though far stronger and convincing evidence has been collected in in vitro as compared to in vivo studies. Whether vitamin D is able to regulate at physiological concentrations the human immune system remains unproven to date. Consequently, it is not established if vitamin D status is a factor involved in the pathogenesis of immune-mediated diseases and if cholecalciferol supplementation acts as an adjuvant for autoimmune diseases. The development of autoimmunity is a heterogeneous process, which may involve different organs and systems with a wide range of clinical implications. In the present paper, we reviewed the current evidences regarding vitamin D role in the pathogenesis and management of different autoimmune diseases.

Efficacy of Vitamin D3 Buccal Spray Supplementation Compared to Other Delivery Methods: A Systematic Review of Superiority Randomized Controlled Trials

(1) Background: Vitamin D deficiency is an important public health concern and supplementation is common for this deficiency. Many different modes of delivering supplementation have been proposed in order to enhance absorption and utilization. The present review compared the efficacy of vitamin D3 buccal spray against other forms of supplementation delivery. (2) Methods: The protocol was registered at PROSPERO (CRD42019136146). Medline/PubMed, CENTRAL and clinicaltrials.gov were searched from their inception until September 2019, for randomized controlled trials (RCTs) that compare vitamin D3 delivery via sublingual spray against other delivery methods. Eligible RCTs involved humans, of any age and health status, published in any language that evaluated changes in plasma 25(OH)D concentrations. Three reviewers independently extracted data, assessed risk of bias (RoB) and the quality of the trials. (3) Results: Out of 9759 RCTs, four matched the predefined criteria. Intervention duration ranged from 30 days to 3 months whereas vitamin D3 dosage ranged between 800 and 3000 IU/day. One RCT advocated for the superiority of buccal spray in increasing plasma 25(OH)D concentrations, although several limitations were recorded in that trial. The rest failed to report differences in post-intervention 25(OH)D concentrations between delivery methods. Considerable clinical heterogeneity was observed due to study design, intervention duration and dosage, assays and labs used to perform the assays, population age and health status, not allowing for synthesis of the results. (4) Conclusions: Based on the available evidence, delivery of vitamin D3 via buccal spray does not appear superior to the other modes of delivery. Future RCTs avoiding the existing methodological shortcomings are warranted.

Demethyleneberberine attenuates concanavalin A-induced autoimmune hepatitis in mice through inhibition of NF-κB and MAPK signaling

Demethyleneberberine (DMB) is a natural product which has been reported to possess mitochondria-targeting anti-oxidative and anti-inflammatory effect. However, the pharmacological action and molecular mechanism of DMB on autoimmune hepatitis (AIH) have not been explored. In this study, AIH was induced by intravenously injecting Con A (20 mg/kg) in mice for 8 h, and DMB protected against Con A-induced AIH, evidenced by obvious reduction of hepatic enzymes in serum and histological lesion. DMB significantly inhibited the infiltration of CD4⁺ T cell and Kupffer cell as well as the expression of inflammatory cytokines, such as TNF-α, IL-6, IL-1β and IFN-γ by ELISA and qPCR analysis. Western blotting analysis illustrated that DMB remarkably inhibited Con A-induced phosphorylation of IKK, IκB, NF-κB p65, ERK, JNK, p38 MAPK and STAT3 induced by Con A. Moreover, DMB also effectively suppressed hepatic oxidative stress with reduction of MDA and elevation of GSH. Taken together, our findings indicated that DMB could prevent Con A-induced AIH by regulating NF-κB and MAPK signaling, suggesting that DMB can serve as a promising candidate for therapy of AIH.

Examining pathogenic concepts of autoimmune hepatitis for cues to future investigations and interventions

BACKGROUND

Multiple pathogenic mechanisms have been implicated in autoimmune hepatitis, but they have not fully explained susceptibility, triggering events, and maintenance or escalation of the disease. Furthermore, they have not identified a critical defect that can be targeted. The goals of this review are to examine the diverse pathogenic mechanisms that have been considered in autoimmune hepatitis, indicate investigational opportunities to validate their contribution, and suggest interventions that might evolve to modify their impact. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Genetic and epigenetic factors can affect susceptibility by influencing the expression of immune regulatory genes. Thymic dysfunction, possibly related to deficient production of programmed cell death protein-1, can allow autoreactive T cells to escape deletion, and alterations in the intestinal microbiome may help overcome immune tolerance and affect gender bias. Environmental factors may trigger the disease or induce epigenetic changes in gene function. Molecular mimicry, epitope spread, bystander activation, neo-antigen production, lymphocytic polyspecificity, and disturbances in immune inhibitory mechanisms may maintain or escalate the disease. Interventions that modify epigenetic effects on gene expression, alter intestinal dysbiosis, eliminate deleterious environmental factors, and target critical pathogenic mechanisms are therapeutic possibilities that might reduce risk, individualize management, and improve outcome. In conclusion, diverse pathogenic mechanisms have been implicated in autoimmune hepatitis, and they may identify a critical factor or sequence that can be validated and used to direct future management and preventive strategies.

Vitamin D supplementation for the prevention or depletion of side effects of therapy with alemtuzumab in multiple sclerosis

PURPOSE OF REVIEW

Not only the multiple sclerosis specialist but also the general neurologist and primary care practitioner are increasingly aware of possible adverse events (AEs) by treatment with alemtuzumab (over 47% risk of secondary autoimmune-mediated diseases). Vitamin D supplementation's effect (VDS) to reduce these autoimmune AEs is poorly performed in routine practice. This article seeks to justify why this simple, inexpensive, patient-friendly therapy should be seriously discussed.

RECENT FINDINGS

Patients who have developed autoimmunity also show a high basal level of IL-21, a cytokine which increases the growth of auto-reactive T-cells. For side effects such as thyroid dysfunction, autoimmune thrombocytopenia, autoimmune hemolytic anemia, autoimmune hepatitis, diabetes mellitus type 1, and alopecia areata/alopecia totalis, VDS may have an impact on the immunological mechanism, in particular lowering levels of IL-17 and IL-21.

SUMMARY

The potential role of vitamin D in influencing autoimmune diseases is evident. If a life-threatening side-effect can be prevented by high-dose VDS, it is ethical to initiate this add-on therapy despite contradictory results in studies on the effectiveness of VDS.

Effects of vitamin D supplementation on insulin resistance and dyslipidemia in overweight and obese premenopausal women

INTRODUCTION

Vitamin D deficiency is a common problem, and it is related to increased risk of obesity, metabolic syndrome, atherosclerosis, and cardiovascular disease. Vitamin D has a beneficial effect on dyslipidemia and insulin secretion. We aimed to investigate the impact of vitamin D3 supplementation on anthropometric and laboratory parameters in overweight and obese premenopausal women.

MATERIAL AND METHODS

Seventy-two overweight and 50 obese vitamin-D-deficient premenopausal women (mean age: 43.1 ±10.4 years) were included in the study. Baseline mean 25-hydroxyvitamin D [25(OH)D] level was 6.1 (min.-max. = 2.9-15.8) ng/ml in overweight and was 5.6 (min.-max. = 3.0-22.0) ng/ml in obese subjects. At baseline and at the sixth month of supplementation, serum 25(OH)D, intact parathormone (iPTH), calcium, phosphorus, homeostasis model assessment of insulin resistance (HOMA-IR), and lipid profiles were assessed.

RESULTS

Following vitamin D3 supplementation in overweight and obese subjects, serum 25(OH)D increased from 6.1 to 34.7 ng/ml and 5.6 to 34.7 ng/ml, respectively (p < 0.001). At the sixth month of supplementation in both overweight and obese subjects, a significant reduction was detected in HOMA-IR (p < 0.001), low-density lipoprotein cholesterol (LDL-C) (p = 0.046, p = 0.044; respectively) and iPTH levels (p ≤ 0.001, p < 0.001; respectively). A negative adjusted correlation was found between changes in 25(OH)D and HOMA-IR (r = -0.581, p < 0.001; r = -0.389, p = 0.005; respectively). A 1 ng/ml increase in serum 25(OH)D level led to a 0.30-fold reduction in HOMA-IR level (p = 0.002).

CONCLUSIONS

Our results support the effect of vitamin D3 supplementation in HOMA-IR and LDL-C improvement in both obese and overweight subjects. Further studies focused on low serum 25(OH)D levels with insulin resistance and dyslipidemia are needed.

High Prevalent Hypovitaminosis D Is Associated with Dysregulation of Calcium-parathyroid Hormone-vitamin D Axis in Patients with Chronic Liver Diseases

Background and Aims: Although hypovitaminosis D is common among patients with chronic liver disease (CLD), the data are inconsistent on its prevalence and its relationship with CLD. This study aimed to estimate the prevalence of hypovitaminosis D among patients with CLD and to determine the relationship between hypovitaminosis D and severity of liver dysfunction, and calcium (Ca), phosphate (PO4) and parathyroid hormone (PTH) levels in CLD. Methods: The study included 236 CLD patients attending the Department of Hepatology, Rajiv Gandhi Government General Hospital (Chennai, India). Serum levels of 25-hydroxyvitamin D (25(OH)D), PTH, Ca, and PO4 were estimated. Severity of liver dysfunction was graded using the Child-Turcotte-Pugh (CTP) score. Results: The first report from our population showed that 162 of 236 (68.6%) CLD patients had hypovitaminosis D (25(OH)D levels of <30 ng/mL), with higher frequency (124/162) 76.5% among CTP B, C patients. Significant negative correlation (r = -0.288, p = 0.0001) between 25(OH)D and CTP scores was noted in hypovitaminosis D conditions. Level of 25(OH)D was correlated negatively with PTH (r = -0.537, p = 0.0001), positively with Ca (r = 0.657, p = 0.0001), and positively with PO4 (r = 0.477, p = 0.0001) in sufficient vitamin D conditions. Conclusions: Hypovitaminosis D is associated with higher CTP scores and is strongly associated with dysregulation of the Ca-PTH-vitamin D axis in CLD. Timely measurement of vitamin D levels is essential, along with levels of PTH, Ca and PO4, to manage CLD patients.

Chronic hepatitis B virus infection is associated with decreased serum 25(OH)D concentration in non-cirrhotic patients

Aim of the study

Recent reports provide evidence for the immunomodulatory properties of vitamin D. Decreased vitamin D levels may contribute to the progression of liver disease in hepatitis B virus (HBV) infection. This study aims to assess serum 25(OH)D in patients with chronic HBeAg-negative HBV (CHB) infection at different phases of disease.

Material and methods

Fifty-eighty patients with CHB, 10 with a history of HBsAg/anti-HBs seroconversion, were enrolled. The control group consisted of 9 healthy volunteers. Serum 25(OH)D concentration was assessed by ELISA.

Results

Serum 25(OH)D concentration was significantly lower in the CHB group in comparison to the HC group. It did not differ across the consecutive phases of the HBeAg-negative HBV infection. Negative correlations between serum 25(OH)D and alanine aminotransferase (ALT) as well as frequency of peripheral blood monocytes were observed. Serum 25(OH)D in samples collected in winter was significantly lower in comparison to the pool of samples collected in the summer. Serum 25(OH)D concentration was not associated with the phases of HBV-infection, HBV viral load, APRI or liver histology.

Conclusions

Serum 25(OH)D is significantly decreased in HBV infection irrespectively of the phase of the infection and negatively correlates with serum ALT level, which may reflect the deterioration of liver function. Based on our results, we can conclude that the role of vitamin D in the immune control of HBV infection is probably irrelevant.

Editorial: the role of vitamin D in autoimmune hepatitis

Linked Content

This article is linked to Ebadi et al papers. To view these articles, visit https://doi.org/10.1111/apt.15029 and https://doi.org/10.1111/apt.15091.

Evolving Role of Vitamin D in Immune-Mediated Disease and Its Implications in Autoimmune Hepatitis

Vitamin D has immunomodulatory, anti-inflammatory, antioxidant, and anti-fibrotic actions that may impact on the occurrence and outcome of immune-mediated disease. The goals of this review are to describe the nature of these expanded roles, examine the implications of vitamin D deficiency in autoimmune hepatitis, and identify opportunities for future investigation. Abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. Vitamin D receptors are expressed on the principal cell populations involved in the innate and adaptive immune responses. Macrophages and dendritic cells can produce 1,25-dihydroxyvitamin D within the microenvironment. This active form of vitamin D can inhibit immune cell proliferation, promote an anti-inflammatory cytokine profile, expand regulatory T cells, enhance glucocorticoid actions, increase glutathione production, and inhibit hepatic stellate cells. Vitamin D deficiency has been commonly present in patients with immune-mediated liver and non-liver diseases, and it has been associated with histological severity, advanced hepatic fibrosis, and non-response to conventional glucocorticoid therapy in autoimmune hepatitis. Vitamin D analogues with high potency, low calcemic effects, and independence from hepatic hydroxylation are possible interventions. In conclusion, vitamin D has properties that could ameliorate immune-mediated disease, and vitamin D deficiency has been a common finding in immune-mediated liver and non-liver diseases, including autoimmune hepatitis. Loss of vitamin D-dependent homeostatic mechanisms may promote disease progression. Vitamin D analogues that are independent of hepatic hydroxylation constitute an investigational opportunity to supplement current management of autoimmune hepatitis.

Severe vitamin D deficiency is a prognostic biomarker in autoimmune hepatitis

BACKGROUND

Vitamin D deficiency has been implicated in the outcome of chronic liver disease.

AIM

To determine the frequency of severe vitamin D deficiency in autoimmune hepatitis (AIH), assess its association with treatment non-response, and evaluate the relationship between vitamin D status and liver-related mortality and need for transplantation.

METHODS

Two hundred and nine patients were evaluated by liver tissue examination at presentation. Serum vitamin D levels were determined, and serum levels <25 nmol/L (10 ng/mL) were considered severely deficient. Treatment non-response was defined as non-normalised aspartate aminotransferase/alanine aminotransferase and immunoglobulin G levels during conventional immunosuppressive therapy. Univariate and multivariate analyses were performed using binary logistic regression and Cox proportional hazards model.

RESULTS

The mean vitamin D level was 60 ± 38 nmol/L (range, 3-263 nmol/L), and 42 patients (20%) had severe vitamin D deficiency. Treatment non-response was more common in patients with severe vitamin D deficiency than in patients without (59% vs 41%, P = 0.04). Severe vitamin D deficiency was also independently associated with a higher risk of developing cirrhosis (HR 3.40; 95% CI 1.30-8.87, P = 0.01) and liver-related mortality or requirement for liver transplantation (LT; HR 5.26, 95% CI, 1.54-18.0, P = 0.008). Patients with persistent severe deficiency following vitamin D supplementation continued to have poor outcomes.

CONCLUSIONS

Severe vitamin D deficiency is associated with treatment non-response, progression to cirrhosis, and liver-related death or need for LT. Severe vitamin D deficiency is a prognostic biomarker in AIH.

Vitamin D and liver fibrosis: Molecular mechanisms and clinical studies

Vitamin D plays a primary role in regulation of bone metabolism and calcium homeostasis. Interestingly, emerging evidence suggests protective effects of vitamin D against liver fibrogenesis. However, the precise mechanisms of this action remain mysterious. Herein, this review aimed to summarize the role of vitamin D in liver fibrosis pathology and to update the current comprehensive knowledge regarding the clinical utility of vitamin D-based treatment in liver fibrosis. In regard to its effect on liver fibrosis, vitamin D possesses an anti-fibrotic effect on hepatic stellate cells via vitamin D receptor-mediated specific signal transduction pathways, which in turn inhibit expression of pro-fibrogenic genes. Furthermore, several studies demonstrated a significant association between low vitamin D levels and an increased risk of liver fibrosis. Additionally, high prevalence of vitamin D deficiency was noted in patients with liver fibrosis, suggesting the use of vitamin D status as a biochemical marker reflecting the progression of liver fibrosis. It is therefore reasonable to postulate that vitamin D supplementation being a cost effective and relative simple procedure may benefit to liver fibrosis. Nevertheless, further research is needed to fully elucidate its regulatory role in inhibiting liver fibrogenesis and to estimate the safety and efficiency of vitamin D supplementation as a relatively inexpensive treatment for liver fibrosis in patients with chronic liver diseases.

An Argument for Vitamin D, A, and Zinc Monitoring in Cirrhosis

Malnutrition is prevalent in cirrhosis. Vitamin and mineral deficiencies, including vitamin D, vitamin A, and zinc, are common and have been shown to correlate with survival. Our aim was to review the mechanisms of vitamin D, vitamin A, and zinc deficiencies in cirrhosis and the clinical assessment of affected patients, their outcomes based on the current literature, and management. This is a narrative review including the relevant literature for cirrhosis and vitamin D, vitamin A, and zinc deficiencies. Vitamin D deficiency has important effects in cirrhosis, regardless of the cause of chronic liver disease.These effects include associations with fibrosis and outcomes such as infections, hepatocellular carcinoma, and mortality. Vitamin A deficiency is associated with liver disease progression to cirrhosis and clinical decompensation, including occurrence of ascites or hepatic encephalopathy. Zinc deficiency can lead to hepatic encephalopathy and impaired immune function. Such deficiencies correlate with patient survival and disease severity. Caution should be applied when replacing vitamin D, vitamin A, and zinc to avoid toxicity. Identification and appropriate treatment of vitamin and mineral deficiencies in cirrhosis may reduce specific nutritional and cirrhosis-related adverse events. Routine monitoring of vitamin A, vitamin D and zinc levels in cirrhosis should be considered.

Vitamin D Deficiency Is Highly Prevalent in Critically Ill Patients and a Risk Factor for Mortality: A Prospective Observational Study Comparing Noncirrhotic Patients and Patients With Cirrhosis

INTRODUCTION

A 25-hydroxyvitamin D, 25(OH)D, deficiency is common among critically ill patients and correlated with increased mortality. Furthermore, deficiency is associated with advanced liver disease. However, there are no studies available comparing the dimensions and consequences of a 25(OH)D deficiency between patients with and without liver cirrhosis in the setting of intensive care units (ICUs). This study focuses on differences in 25(OH)D status between critically ill noncirrhosis patients and patients with cirrhosis (primary end point), hypothesizing that deficiency and its impact on mortality risk are even more pronounced in patients with cirrhosis.

METHODS

We performed a prospective observational study of 176 patients (noncirrhosis patients, N = 114; patients with cirrhosis, N = 62) with a laboratory assessment of 25(OH)D on ICU admission and survival analyses after 180 days.

RESULTS

On admission, 55% of patients showed a severe deficiency, 25(OH)D <10 ng/mL, and a further 23% moderate deficiency (10-19 ng/mL). The overall median level of 25(OH)D was 8.0 (5.0-18.0) ng/mL (10.5 [6.0-21.3] in noncirrhosis patients vs 7.0 [4.8-10.0] in patients with cirrhosis; P < .001). We found extremely low levels particularly in patients without prior vitamin D supplementation (6.0 [4.0-7.5] in patients with cirrhosis vs 8.0 [5.0-12.0] ng/mL in noncirrhosis patients; P = .004). Vitamin D status correlated inversely with the sequential organ failure assessment, acute and physiology chronic health evaluation, model of end-stage liver disease, and Child-Pugh scores. Survival analyses categorized 25(OH)D levels <10 ng/mL as a high-risk factor for mortality 180 days after admission (hazard ratio [HR]: 2.45, 95% confidence interval [CI] = 1.60-3.70; P < .001). In patients with cirrhosis, a severe deficiency (<10 ng/mL) involved a significantly higher mortality risk than in noncirrhosis patients (HR: 2.30, 95% CI = 1.39-3.82; P = .001). In cases of admission levels ≥10 ng/mL, however, mortality risk was similar between patients with cirrhosis and noncirrhosis patients (HR: 1.08, 95% CI = 0.43-2.73; P = .873).

CONCLUSIONS

Hypovitaminosis D is a highly frequent disorder in critically ill patients admitted to ICU. A severe deficiency with levels <10 ng/mL is a high risk factor for increased mortality, especially in patients with cirrhosis.

Under-Evaluated or Unassessed Pathogenic Pathways in Autoimmune Hepatitis and Implications for Future Management

Autoimmune hepatitis is a consequence of perturbations in homeostatic mechanisms that maintain self-tolerance but are incompletely understood. The goals of this review are to describe key pathogenic pathways that have been under-evaluated or unassessed in autoimmune hepatitis, describe insights that may shape future therapies, and encourage investigational efforts. The T cell immunoglobulin mucin proteins constitute a family that modulates immune tolerance by limiting the survival of immune effector cells, clearing apoptotic bodies, and expanding the population of granulocytic myeloid-derived suppressor cells. Galectins influence immune cell migration, activation, proliferation, and survival, and T cell exhaustion can be induced and exploited as a possible management strategy. The programmed cell death-1 protein and its ligands comprise an antigen-independent inhibitory axis that can limit the performance of activated T cells by altering their metabolism, and epigenetic changes can silence pro-inflammatory genes or de-repress anti-inflammatory genes that affect disease severity. Changes in the intestinal microbiota and permeability of the intestinal mucosal barrier can be causative or consequential events that affect the occurrence and phenotype of immune-mediated disease, and they may help explain the female propensity for autoimmune hepatitis. Perturbations within these homeostatic mechanisms have been implicated in experimental models and limited clinical experiences, and they have been favorably manipulated by monoclonal antibodies, recombinant molecules, pharmacological agents or dietary supplements. In conclusion, pathogenic mechanisms that have been implicated in other systemic immune-mediated and liver diseases but under-evaluated or unassessed in autoimmune hepatitis warrant consideration and rigorous evaluation.

The Role of Invariant NKT in Autoimmune Liver Disease: Can Vitamin D Act as an Immunomodulator?

Natural killer T (NKT) cells are a distinct lineage of T cells which express both the T cell receptor (TCR) and natural killer (NK) cell markers. Invariant NKT (iNKT) cells bear an invariant TCR and recognize a small variety of glycolipid antigens presented by CD1d (nonclassical MHC-I). CD1d-restricted iNKT cells are regulators of immune responses and produce cytokines that may be proinflammatory (such as interferon-gamma (IFN-γ)) or anti-inflammatory (such as IL-4). iNKT cells also appear to play a role in B cell regulation and antibody production. Alpha-galactosylceramide (α-GalCer), a derivative of the marine sponge, is a potent stimulator of iNKT cells and has been proposed as a therapeutic iNKT cell activator. Invariant NKT cells have been implicated in the development and perpetuation of several autoimmune diseases such as multiple sclerosis and systemic lupus erythematosus (SLE). Animal models of SLE have shown abnormalities in iNKT cells numbers and function, and an inverse correlation between the frequency of NKT cells and IgG levels has also been observed. The role of iNKT cells in autoimmune liver disease (AiLD) has not been extensively studied. This review discusses the current data with regard to iNKT cells function in AiLD, in addition to providing an overview of iNKT cells function in other autoimmune conditions and animal models. We also discuss data regarding the immunomodulatory effects of vitamin D on iNKT cells, which may serve as a potential therapeutic target, given that deficiencies in vitamin D have been reported in various autoimmune disorders.

Emerging therapeutic biomarkers of autoimmune hepatitis and their impact on current and future management

Autoimmune hepatitis lacks a quantifiable biomarker that is close to its pathogenic mechanisms and that accurately reflects inflammatory activity, correlates with treatment response, and ensures inactive disease before treatment withdrawal. Areas covered: Micro-ribonucleic acids, programmed death-1 protein and its ligands, macrophage migration inhibitory factor, soluble CD163, B cell activating factor, and metabolite patterns in blood were considered the leading candidates as therapeutic biomarkers after search of PubMed from August 1981 to August 2017 using the search words 'biomarkers of autoimmune hepatitis'. Expert commentary: Each of the candidate biomarkers is close to the putative pathogenic mechanisms of autoimmune hepatitis, and each has attributes that support its potential role as a surrogate marker of inflammatory activity that can be monitored during treatment. Future studies must demonstrate the superiority of each biomarker to conventional indices of inflammatory activity and validate their correlation with treatment response and outcome. A reliable therapeutic biomarker would facilitate the individualization of current management algorithms, ensure that pathogenic mechanisms were disrupted or eliminated prior to treatment withdrawal, and reduce the frequency of relapse or unnecessary protracted therapy. The biomarker might also prove to be a target of next-generation therapies.