Serum inflammatory cytokines, complement components, and soluble interleukin 2 receptor in primary biliary cirrhosis

Aberrant cytokine and VCAM-1 expression in patients with viral and non-viral related liver cirrhosis

The study aim was to compare the alterations in the expression levels of proinflammatory and chemotactic cytokines as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-17A and IL-8, the down regulatory cytokine IL-10, in addition to the vascular cell adhesion molecule-1 (VCAM-1) gene in different groups of patients with cirrhosis due to various etiologies. This case-control study included 84 patients suffering from cirrhosis of viral and non-viral etiologies and 20 sex and age-matched healthy controls. All patients were subjected to detailed history taking, clinical examination, and liver function assessment. The expression levels of TNF-α, IL-17A, IL-8, IL-10, and VCAM-1 were assessed in peripheral blood mononuclear cells by real-time PCR. Patients with cirrhosis showed marked changes in the tested gene expression levels relative to the control group. Higher expression levels of all genes except IL-10 were seen in patients of the viral than in the non-viral groups. Most of the significant correlations of liver function parameters were observed with TNF-α in both the viral and non-viral groups, followed by IL-17A. Increased TNF-α and IL-17A presented potential risk factors for disease progression to cirrhosis of Child class C.

Gamma-glutamyl transferase predicts pemafibrate treatment response in non-alcoholic fatty liver disease

BACKGROUND AND AIM

Pemafibrate, a selective peroxisome proliferator activated receptor α modulator, has been shown to improve liver function among nonalcoholic fatty liver disease (NAFLD) patients with dyslipidemia. The aim of this retrospective study is to identify predictors of pemafibrate efficacy in NAFLD patients.

METHODS

A total of 75 NAFLD patients with dyslipidemia who received pemafibrate twice per day for 48 weeks were enrolled in this study. We used the FibroScan-aspartate aminotransferase (FAST) score as a benchmark for treatment efficacy.

RESULTS

Median FAST score significantly decreased from 0.96 at baseline to 0.93 at week 48 (P < 0.001). Significant improvements in levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and triglycerides were also noted. The serum level of GGT at baseline was correlated with change in FAST score (r = -0.22, P = 0.049). Changes in AST, ALT, and GGT were positively correlated with change in FAST score (r = 0.71, r = 0.61, and r = 0.38). Multivariate analyses identified age and GGT level at baseline as significantly associated with improvement of FAST score by pemafibrate therapy (odds ratio 1.11, 1.02, respectively). Patients over 50 years of age and with a GGT of 90 IU/L or higher showed significantly greater improvement in the FAST score than other groups.

CONCLUSIONS

Pemafibrate improves the FAST score of NAFLD patients with complicating dyslipidemia, especially in older patients with high GGT level. GGT is useful as an indicator of optimal treatment choice for NAFLD patients with dyslipidemia.

Detection of Lymphadenopathy as a Precursor to Autoimmune Liver Diseases Before Clinical Hepatitis Became Apparent: A Report of Two Cases

Two patients were incidentally diagnosed with intra-abdominal lymphadenopathy on imaging examinations. Although endoscopic ultrasound-guided fine needle aspiration of these areas of lymphadenopathy was performed, their causes remained undetermined. Neither patients had abnormal hepatic enzyme levels at the time lymphadenopathy was detected, but they developed hepatitis 20 months and five months later, respectively. The laboratory data and/or histopathological findings suggested primary biliary cholangitis/cirrhosis (PBC) and autoimmune hepatitis (AIH), respectively. These two patients were each started on appropriate treatment (ursodeoxycholic acid or prednisolone, respectively), their hepatitis ameliorated, and the hepatic enzyme levels recovered to within the normal ranges. These patients' clinical courses suggest that their lymphadenopathy was associated with PBC or AIH and appeared before the causative hepatitis became clinically apparent. We should consider the possibility of latent autoimmune hepatic diseases in cases with cryptogenic intra-abdominal lymphadenopathy even if there is no clinically apparent hepatitis.

Plasma lipidomics of primary biliary cholangitis and its comparison with Sjögren's syndrome

Background

Abnormal lipid metabolism is common in patients with primary biliary cholangitis (PBC). PBC and Sjögren's syndrome (SS) frequently coexist in clinical practice; however, the lipid characteristics of both diseases are unknown. Therefore, we aimed to analyze the plasma lipid profiles of both diseases.

Methods

Plasma samples from 60 PBC patients, 30 SS patients, and 30 healthy controls (HC) were collected, and untargeted lipidomics was performed using ultrahigh-performance liquid chromatography high-resolution mass spectrometry. Potential lipid biomarkers were screened through an orthogonal projection to latent structure discriminant analysis and further evaluated using receiver operating characteristic (ROC) analysis.

Results

A total of 115 lipids were differentially upregulated in PBC patients compared with HC. Seventeen lipids were positively associated with the disease activity of PBC, and ROC analysis showed that all of these lipids could differentiate between ursodeoxycholic acid (UDCA) responders and UDCA non-responders. The top six lipids based on the area under the curve (AUC) values were glycerophosphocholine (PC) (16:0/16:0), PC (18:1/18:1), PC (42:2), PC (16:0/18:1), PC (17:1/14:0), and PC (15:0/18:1). In comparison with SS, 44 lipids were found to be differentially upregulated in PBC. Additionally, eight lipids were found to have a good diagnostic performance of PBC because of the AUC values of more than 0.9 when identified from SS and HC groups, which were lysophosphatidylcholines (LysoPC) (16:1), PC (16:0/16:0), PC (16:0/16:1), PC (16:1/20:4), PC (18:0/20:3), PC (18:1/20:2), PC (20:0/22:5), and PC (20:1/22:5).

Conclusion

Our study revealed differentially expressed lipid signatures in PBC compared with HC and SS. PC is the main lipid species associated with disease activity and the UDCA response in patients with PBC.

Lipocalin-2 Secreted by the Liver Regulates Neuronal Cell Function Through AKT-Dependent Signaling in Hepatic Encephalopathy Mouse Model

Hepatic encephalopathy (HE) associated with liver failure is accompanied by hyperammonemia, severe inflammation, depression, anxiety, and memory deficits as well as liver injury. Recent studies have focused on the liver-brain-inflammation axis to identify a therapeutic solution for patients with HE. Lipocalin-2 is an inflammation-related glycoprotein that is secreted by various organs and is involved in cellular mechanisms including iron homeostasis, glucose metabolism, cell death, neurite outgrowth, and neurogenesis. In this study, we investigated that the roles of lipocalin-2 both in the brain cortex of mice with HE and in Neuro-2a (N2A) cells. We detected elevated levels of lipocalin-2 both in the plasma and liver in a bile duct ligation mouse model of HE. We confirmed changes in cytokine expression, such as interleukin-1β, cyclooxygenase 2 expression, and iron metabolism related to gene expression through AKT-mediated signaling both in the brain cortex of mice with HE and N2A cells. Our data showed negative effects of hepatic lipocalin-2 on cell survival, iron homeostasis, and neurite outgrowth in N2A cells. Thus, we suggest that regulation of lipocalin-2 in the brain in HE may be a critical therapeutic approach to alleviate neuropathological problems focused on the liver-brain axis.

Caspase-10 affects the pathogenesis of primary biliary cholangitis by regulating inflammatory cell death

Primary biliary cholangitis (PBC) is an autoimmune disease that involves chronic inflammation and injury to biliary epithelial cells. To identify critical genetic factor(s) in PBC patients, we performed whole-exome sequencing of five female siblings, including one unaffected and four affected sisters, in a multi-PBC family, and identified 61 rare heterozygote variants that segregated only within the affected sisters. Among them, we were particularly interested in caspase-10, for although several caspases are involved in cell death, inflammation and autoimmunity, caspase-10 is little known from this perspective. We generated caspase-10 knockout macrophages, and then investigated the obtained phenotypes in comparison to those of its structurally similar protein, caspase-8. Unlike caspase-8, caspase-10 does not play a role during differentiation into macrophages, but after differentiation, it regulates the process of inflammatory cell deaths such as necroptosis and pyroptosis more strongly. Interestingly, caspase-10 displays better protease activity than caspase-8 in the process of RIPK1 cleavage, and an enhanced ability to form a complex with RIPK1 and FADD in human macrophages. Higher inflammatory cell death affected the fibrotic response of hepatic stellate cells; this effect could be recovered by treatment with UDCA and OCA, which are currently approved for PBC patients. Our findings strongly indicate that the defective roles of caspase-10 in macrophages contribute to the pathogenesis of PBC, thereby suggesting a new therapeutic strategy for PBC treatment.

Prognostic importance of interleukin 2 receptor for patients with a history of cirrhotic variceal bleeding

OBJECTIVES

Variceal hemorrhage is a fatal complication of cirrhosis. In this study, we aimed to investigate the role of serum interleukin 2 receptor (sIL-2R) as a predictive indicator in patients with a previous history of cirrhosis-related variceal bleeding.

METHODS

A total of 340 cirrhotic patients who had experienced variceal bleeding from December 2016 to December 2018 were enrolled, and were randomly assigned to the modeling group and the validation group. The 3-year variceal rebleeding rate and other outcomes including adverse events were analyzed between patients with different sIL-2R levels.

RESULTS

A time-dependent receiver operating characteristic (ROC) curve of variceal rebleeding indicated that sIL-2R had an area under the ROC curve (AUROC] of 0.731 and 0.837 for the modeling and validation groups, respectively, with a cut-off value of 426 U/mL. Kaplan-Meier analysis showed that higher sIL-2R level was related to an increased risk of variceal rebleeding rate (55.33% vs 24.34%, P = 0.024 and 51.28% vs 15.32%, P = 0.049) and decreased 3-year survival rate (91.16% vs 98.92%, P = 0.013 and 90.52% vs 97.50%, P = 0.180) in the modeling and validation groups. Elevated sIL-2R levels were associated with an increased risk of portal vein thrombosis and severe ascites as well as inferior liver function, hypercoagulable state, and increased portal pressure.

CONCLUSION

High sIL-2R levels were associated with poor prognosis in cirrhotic patients with previous variceal bleeding.

Effect of irradiation on cytokine production in cancer patients

BACKGROUND

Irradiation, which affects cytokine secretion, is used to treat cancer patients. Cytokine levels have correlations to disease parameters, serving as biomarkers for patients. We aim to explore the effect of irradiation on cytokine production both in vitro (using lymphocytes from healthy donors) and in vivo (using serum levels of head and neck cancer patients following irradiation) and correlating them to mucositis severity/need for percutaneous endoscopic gastroscopy (PEG) tube installation.

METHODS

Cytokine production by cultured lymphocytes from healthy donors, in vitro, following irradiation of 5 or 10 Gy. In addition, blood from 23 patients with head and neck cancers, irradiated by 60-72G in vivo, were assessed for inflammatory cytokines (tumor necrosis factor (TNF)α, interleukin (IL)-6, IL-8, IL-18), the anti-inflammatory cytokine IL-10, and the general marker sIL-2R. Following radiation, selected patients who were developing mucositis were treated by PEG tube installation. Changes in cytokine levels were studied as predictive biomarkers of response to therapy/PEG tube installation. Cytokine production levels were measured using ELISAs kits.

RESULTS

Irradiation decreased the levels of all tested cytokines, most notably IL-6 and IL-8, proportional to irradiation dose. In patients, increases in cytokine levels, correlated with mucositis severity and potentially the need for PEG tube installation.

CONCLUSIONS

Irradiation decreased the levels of all cytokines of healthy lymphocytes in a dose-dependent manner, especially those of IL-6 and IL-8. This study shows a correlation between high and increasing levels of inflammatory cytokines, sIL-2R, plus radiation toxicity and the need for PEG. The reduction of cytokine levels after radiotherapy predicts that PEG will not be required. Thus, our study shows that cytokine changes are predictive biomarkers in head and neck cancer patients.

PPARα: A potential therapeutic target of cholestasis

The accumulation of bile acids in the liver leads to the development of cholestasis and hepatocyte injury. Nuclear receptors control the synthesis and transport of bile acids in the liver. Among them, the farnesoid X receptor (FXR) is the most common receptor studied in treating cholestasis. The activation of this receptor can reduce the amount of bile acid synthesis and decrease the bile acid content in the liver, alleviating cholestasis. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) have a FXR excitatory effect, but the unresponsiveness of some patients and the side effect of pruritus seriously affect the results of UDCA or OCA treatment. The activator of peroxisome proliferator-activated receptor alpha (PPARα) has emerged as a new target for controlling the synthesis and transport of bile acids during cholestasis. Moreover, the anti-inflammatory effect of PPARα can effectively reduce cholestatic liver injury, thereby improving patients’ physiological status. Here, we will focus on the function of PPARα and its involvement in the regulation of bile acid transport and metabolism. In addition, the anti-inflammatory effects of PPARα will be discussed in some detail. Finally, we will discuss the application of PPARα agonists for cholestatic liver disorders.

[Hepatic granuloma-A diagnostic challenge]

Hepatic granulomas can have various causes and their detection requires a systematic diagnostic evaluation. First, identification of risk factors for granulomatous diseases and the exclusion of extrahepatic organ manifestation are necessary. Laboratory investigations and serological screening for the most common underlying diseases of liver granulomas in Germany, such as primary biliary cholangitis (PBC), sarcoidosis and infectious causes (primarily tuberculosis and hepatitis C infections), are recommended. A liver biopsy is essential for confirming the diagnosis, whereby a minilaparoscopically guided tissue sampling offers many advantages, such as the macroscopic detection of granulomas on the liver surface, on the peritoneum or on the spleen. Whether the detection of hepatic granulomas results in a therapeutic consequence, depends decisively on the underlying primary disease. If hepatic granulomas are present without concomitant liver parenchymal damage or other manifestations that would make treatment necessary, a watch and wait approach under close clinical and laboratory monitoring is sufficient. If liver values increase or in cases of hepatic parenchymal damage, urgent treatment of the underlying disease is indicated.

Limited association between infections, autoimmune disease and genetic risk and immune activation in severe mental disorders

BACKGROUND

Low-grade inflammation may be part of the underlying mechanism of schizophrenia and bipolar disorder. We investigated if genetic susceptibility, infections or autoimmunity could explain the immune activation.

METHODS

Seven immune markers were selected based on indicated associations to severe mental disorders (IL-1Ra, sIL-2R, IL-18, sgp130, sTNFR-1, APRIL, ICAM-1) and measured in plasma of patients with schizophrenia (SCZ, N = 732) and bipolar spectrum disorders (BD, N = 460) and healthy controls (HC, N = 938). Information on rate of infections and autoimmune diseases were obtained from Norwegian national health registries for a twelve-year period. Polygenic risk scores (PRS) of SCZ and BD were calculated from genome-wide association studies. Analysis of covariance were used to test effects of infection rate, autoimmune disease and PRS on differences in immune markers between patients and HC.

RESULTS

Infection rate differed between all groups (BD > HC > SCZ, all p < 0.001) whereas autoimmune disease was more frequent in BD compared to SCZ (p = 0.004) and HC (p = 0.003). sIL-2R was positively associated with autoimmune disease (p = 0.001) and negatively associated with PRS of SCZ (p = 0.006) across SCZ and HC; however, associations represented only small changes in the difference of sIL-2R levels between SCZ and HC.

CONCLUSION

There were few significant associations between rate of infections, autoimmune disease or PRS and altered immune markers in SCZ and BD, and the detected associations represented only small changes in the immune aberrations. The findings suggest that most of the low-grade inflammation in SCZ and BD is explained by other factors than the underlying PRS, autoimmunity and infection rates.

ADAM Metalloproteinase Domain 17 Regulates Cholestasis-Associated Liver Injury and Sickness Behavior Development in Mice

Disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) is a ubiquitously expressed membrane-bound enzyme that mediates shedding of a wide variety of important regulators in inflammation including cytokines and adhesion molecules. Hepatic expression of numerous cytokines and adhesion molecules are increased in cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), however, the pathophysiological role of ADAM17 in regulating these conditions remains unknown. Therefore, we evaluated the role of ADAM17 in a mouse model of cholestatic liver injury due to bile duct ligation (BDL). We found that BDL enhanced hepatic ADAM17 protein expression, paralleled by increased ADAM17 bioactivity. Moreover, inhibition of ADAM17 bioactivity with the specific inhibitor DPC 333 significantly improved both biochemical and histological evidence of liver damage in BDL mice. Patients with cholestatic liver disease commonly experience adverse behavioral symptoms, termed sickness behaviors. Similarly, BDL in mice induces reproducible sickness behavior development, driven by the upregulated expression of cytokines and adhesion molecules that are in turn regulated by ADAM17 activity. Indeed, inhibition of ADAM17 activity significantly ameliorated BDL-associated sickness behavior development. In translational studies, we evaluated changes in ADAM17 protein expression in liver biopsies obtained from patients with PBC and PSC, compared to normal control livers. PSC and PBC patients demonstrated increased hepatic ADAM17 expression in hepatocytes, cholangiocytes and in association with liver-infiltrating immune cells compared to normal controls. In summary, cholestatic liver injury in mice and humans is associated with increased hepatic ADAM17 expression. Furthermore, inhibition of ADAM17 activity improves both cholestatic liver injury and associated sickness behavior development, suggesting that ADAM17 inhibition may represent a novel therapeutic approach for treating patients with PBC/PSC.

Selenium reduces nociceptive response in acute 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced neurotoxicity

The potential of Se to alleviate pain associated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity was investigated.

Swiss mice were intraperitoneally injected with MPTP (20 mg/kg) 4 times with an interval of 2 h in 1 day. Seven days after MPTP injection, the mice (n = 5 mice per group) were randomly assigned to groups: MPTP-, DOPA (50 mg/kg)-, Se4 (0.4 mg/kg)-, Se6 (0.6 mg/kg)-, DOPA+Se4-, and DOPA+Se6-treated groups were compared with controls. MPTP mice were treated for seven days; thereafter, motor-coordination and nociceptive-motor reactions were assessed. Pro-inflammatory cytokines (IL-1β, IL-6 and TNFα), and selected pain biomarkers (substance P (SP), glutamate and β-endorphin) were assessed in the serum and the substantial nigra pars compacta (SNpc).

Motor activity was increased slightly by Se (0.6 or 0.4 mg/kg) vs. MPTP (10.48 ± 2.71 or 11.81 ± 1.28 s vs. 3.53 ± 0.06 s respectively) but considerably increased by DOPA (50 mg/kg) vs. MPTP (50.47 ± 3.06 s vs. 3.53 ± 0.06 s respectively). Se and DOPA increased nociceptive threshold but Se alone reduced both serum and SN pro-inflammatory cytokines. Se modulates SP while DOPA modulates SP and glutamate in the SNpc of mice treated with MPTP.

Se suppressed pro-inflammatory cytokines and restored the basal pain biomarkers in the SNpc of mice treated with MPTP. Se requires further study as analgesic adjuvant.

Investigation of possible neuroprotective effects of some plant extracts on brain in bile duct ligated rats

This study aimed to investigate the possible neuroprotective effects of bitter melon (BM), chard, and parsley extracts on oxidative damage that may occur in the brain of rats with bile duct ligation (BDL)-induced biliary cirrhosis. It was observed that lipid peroxidation (LPO), sialic acid (SA), and nitric oxide (NO) levels increased; glutathione (GSH) levels, catalase (CAT) activity, and tissue factor (TF) activity decreased significantly in the BDL group. However, in groups with BDL given BM, chard, and parsley extracts LPO, SA, NO levels decreased; GSH levels and CAT activities increased significantly. No significant differences were observed between groups in total protein, glutathione-S-transferase, superoxide dismutase, and boron. Histological findings were supported by the biochemical results. BM, chard, and parsley extracts were effective in the regression of oxidant damage caused by cirrhosis in the brain tissues. PRACTICAL APPLICATIONS: Bitter melon (BM), chard, and parsley have antioxidant properties due to their bioactive compounds which are involved in scavenging free radicals, suppressing their production, and stimulating the production of endogenous antioxidant compounds. Since BM, chard, and parsley extracts were found to be effective in the regression of oxidant damage caused by cirrhosis in the brain tissues, these plant extracts may be an alternative in the development of different treatment approaches against brain damage in cirrhosis. At the same time, these species have been used as food by the people for many years. Therefore, they can be used safely as neuroprotective agents in treatment.

Implications of Breast Cancer Chemotherapy-Induced Inflammation on the Gut, Liver, and Central Nervous System

Breast Cancer is still one of the most common cancers today; however, with advancements in diagnostic and treatment methods, the mortality and survivorship of patients continues to decrease and increase, respectively. Commonly used treatments today consist of drug combinations, such as doxorubicin and cyclophosphamide; docetaxel, doxorubicin, and cyclophosphamide; or doxorubicin, cyclophosphamide, and paclitaxel. Although these combinations are effective at destroying cancer cells, there is still much to be understood about the effects that chemotherapy can have on normal organ systems such as the nervous system, gastrointestinal tract, and the liver. Patients can experience symptoms of cognitive impairments or “chemobrain”, such as difficulty in concentrating, memory recollection, and processing speed. They may also experience gastrointestinal (GI) distress symptoms such as diarrhea and vomiting, as well as hepatotoxicity and long term liver damage. Chemotherapy treatment has also been shown to induce peripheral neuropathy resulting in numbing, pain, and tingling sensations in the extremities of patients. Interestingly, researchers have discovered that this array of symptoms that cancer patients experience are interconnected and mediated by the inflammatory response.

The role of complement activation in autoimmune liver disease

INTRODUCTION

The complement system, an essential part of the innate immune system, is involved in various autoimmune diseases. Activation of the complement system by autoantibodies results in immune activation and tissue damage. At the moment little is known about the role of the complement system in autoimmune liver disease, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Since inhibition of the complement system is currently being tested in several autoimmune diseases as a therapeutic option, its role in autoimmune liver disease requires further clarification.

METHODS

A review of the literature was performed on studies investigating complement activation in PBC, PSC and AIH. Since data on AIH were lacking immunohistochemical staining for IgG, C1q, C3d, C4d and C5b9 was performed on liver tissue of nine AIH patients, two healthy controls and one positive control (acute liver failure caused by paracetamol intoxication).

RESULTS

Immunohistochemical analysis in AIH revealed increased production of C3 and C4 by hepatocytes. Despite a strong staining for IgG in the immune infiltrate in AIH, C3d, C4d and C5b9 deposition was only present in one AIH patient and the deposition was restricted to the interface between portal tracts and liver parenchyma. No deposition was found in all other AIH patients or healthy controls. Literature review showed raised plasma C3 and C4 levels in AIH, PBC and PSC patients compared to healthy controls. For PBC and PSC no complement depositions at the bile ducts were reported.

CONCLUSION AND DISCUSSION

Although complement is involved in various autoimmune diseases, the role of complement in autoimmune liver disease seems limited. Therefore it is unlikely that complement inhibition will become a novel treatment option for these diseases.

Inflammasome Is Activated in the Liver of Cholestatic Patients and Aggravates Hepatic Injury in Bile Duct-Ligated Mouse

BACKGROUND & AIMS

Inflammation plays an important role in the pathogenesis of cholestatic liver injury, but it is unclear whether the inflammasome is involved and is the objective of this study.

METHODS

Gene expression was analyzed in the livers of patients with primary biliary cholangitis (n = 15) and primary sclerosing cholangitis (n = 15). Bile duct ligation (BDL) or sham operation was performed in wild-type (WT) and Caspase-1^-/- (Casp1^-/-) mice for 7 days. Mouse hepatocytes and macrophages were treated with bile acids.

RESULTS

Caspase-1, NLRP1, NLRP3 and IL-1β were significantly increased in the livers of cholestatic patients when compared to healthy control subjects (n = 9). Significantly higher levels of plasma IL-1β (826 vs 345 pg/ml), ALT (674 vs 482 U/L) and ALP (900 vs 622 U/L) were seen in WT BDL mice compared to Casp1^-/- BDL mice. Caspase-1 cleavage was found only in WT BDL livers. Assessment of liver histology indicated more fibrosis in Casp1^-/- BDL mice than in WT BDL mice, confirmed by analyses of liver hydroxyproline content and the expression of fibrotic genes. Profiling of immune cells revealed that there were more macrophages in Casp1^-/- BDL livers than in WT BDL livers. Further macrophage phenotype characterization indicated that Casp1^-/- BDL livers had more M2 anti-inflammatory macrophages evidenced by more CD206 positive cells and higher expression of IL-4, CD163, Fizz1 and IL-33. When mouse hepatocytes and peritoneal macrophages were exposed to cholestatic levels of major endogenous bile acids (300μM TCA), neither IL-1β induction nor procaspase-1 cleavage were detected.

CONCLUSIONS

The inflammasome exacerbates cholestatic liver injury, but bile acids do not directly activate the inflammasome.

The complement system in liver diseases: Evidence-based approach and therapeutic options

Complement is usually seen to largely originate from the liver to accomplish its tasks systemically - its return to the production site has long been underestimated. Recent progress in genomics, therapeutic effects on complement, standardised possibilities in medical laboratory tests and involvement of complosome brings the complement system with its three major functions of opsonization, cytolysis and phagocytosis back to liver biology and pathology. The LOINC™ system features 20 entries for the C3 component of complement to anticipate the application of artificial intelligence data banks algorythms of which are fed with patient-specific data connected to standard lab assays for liver function. These advancements now lead to increased vigilance by clinicians. This reassessment article will further elucidate the distribution of synthesis sites to the three germ layer-derived cell systems and the role complement now known to play in embryogenesis, senescence, allotransplantation and autoimmune disease. This establishes the liver as part of the gastro-intestinal system in connection with nosological entities never thought of, such as the microbiota-liver-brain axis. In neurological disease etiology infectious and autoimmune hepatitis play an important role in the context of causative viz reactive complement activation. The mosaic of autoimmunity, i.e. multiple combinations of the many factors producing varying clinical pictures, leads to the manifold facets of liver autoimmunity.

Disease Duration and Stage Influence Bone Microstructure in Patients With Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is known to be a major risk factor for osteoporosis reflected by a reduction of bone mineral density (BMD). However, both the extent of the macro- and microstructural alterations of bone as well as the causative factors are unknown. We have retrospectively analyzed a total of 96 patients with PBC and 53 healthy controls matched for age, sex, and body mass index. In addition to dual-energy X-ray absorptiometry (DXA) measurements at the lumbar spine and hip, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to assess the geometric, volumetric, and microstructural changes of bone at the distal radius and tibia. Furthermore, serum analyses and measures of disease duration and stage including transient elastography were performed. Total, cortical, and trabecular volumetric BMD as well as geometric parameters were significantly reduced in PBC patients. Microstructural analysis revealed a significantly lower cortical thickness (p < 0.001) and bone volume per tissue volume (p < 0.001) in the radius and tibia but unchanged trabecular number in patients with PBC (radius: p = 0.42; tibia: p = 0.12). Multivariate regression models pointed out that disease duration and stage are the primary factors that are independently associated with bone loss in PBC. A subgroup analysis of patients with additional autoimmune hepatitis (AIH) revealed no significant changes in bone structure compared with PBC only. Taken together, PBC patients demonstrate severe alterations in bone microstructure that are positively associated with disease duration and stage. By applying HR-pQCT in the distal radius and tibia, a combined bone loss syndrome expressed by a predominant decrease in BMD and cortical thickness could be detected. © 2018 American Society for Bone and Mineral Research.

Liver Illness and Psoriatic Patients

Psoriasis is a chronic inflammatory disease of the skin affecting approximately 2% of the world's population. Systemic treatments, including methotrexate and cyclosporin, are associated with potential hepatotoxicity, due to either direct liver damage or immunosuppression or both immunomediated and a direct liver injury; therefore, treatment of patients with psoriasis poses a therapeutic challenge. The aim of this minireview is to help clinicians in the management of psoriatic patients who develop signs of liver dysfunction. To find relevant articles, a comprehensive search was performed on PubMed, EMBASE, and Cochrane with appropriate combinations of the following keywords being considered: viral hepatitis, nonalcoholic fatty liver disease, psoriasis, hepatotoxicity, drug toxicity, cholestasis, and autoimmune liver diseases.

Risk of secondary osteoporosis due to lobular cholestasis in non-cirrhotic primary biliary cholangitis

BACKGROUND AND AIM

It remains unclear whether primary biliary cholangitis (PBC) represents a risk factor for secondary osteoporosis.

METHODS

A case-control study was conducted to examine bone mineral density and bone turnover markers in middle-aged postmenopausal PBC patients without liver cirrhosis. We compared the incidence of low bone mineral density between propensity-score matched subgroups of PBC patients and healthy controls and investigated the mechanisms underlying unbalanced bone turnover in terms of the associations between bone turnover markers and PBC-specific histological findings.

RESULT

Our analysis included 128 consecutive PBC patients, all postmenopausal women aged in their 50s or 60s, without liver cirrhosis or fragility fracture at the time of PBC diagnosis. The prevalence of osteoporosis was significantly higher in the PBC group than in the control group (26% vs 10%, P = 0.015, the Fisher exact probability test). In most PBC patients (95%), the level of bone-specific alkaline phosphatase was above the normal range, indicating increased bone formation. On the other hand, the urine type I collagen-cross-linked N-telopeptide showed variable levels among our PBC patients, indicating unbalanced bone resorption. Advanced fibrosis was associated with low bone turnover. Lobular cholestasis, evaluated as aberrant keratin 7 expression in hepatocytes, showed significant negative correlations with bone formation and resorption, indicating low bone turnover.

CONCLUSION

Our results show that, compared with healthy controls, even non-cirrhotic PBC patients have significantly higher risk of osteoporosis. Moreover, lobular cholestasis was associated with low bone turnover, suggesting this feature of PBC may itself cause secondary osteoporosis in PBC patients.

NLRP3 inflammasome induced liver graft injury through activation of telomere-independent RAP1/KC axis

Acute-phase inflammation plays a critical role in liver graft injury. Inflammasomes, multi-molecular complexes in the cytoplasm, are responsible for initiating inflammation. Here, we aimed to explore the role of inflammasomes in liver graft injury and further to investigate the regulatory mechanism. In a clinical liver transplant cohort, we found that intragraft expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasomes was significantly up-regulated post-transplantation. Importantly, overexpression of NLRP3 was strongly associated with poor liver function characterized by high levels of ALT, AST, and urea, as well as neutrophil infiltration after transplantation. The significant correlation between NLRP3 and IL-1β mRNA levels led us to focus on one of the associated upstream regulators, telomere-independent repressor activator protein 1 (RAP1), which was further proved to be co-localized with NLRP3 in neutrophils. In the liver of a mouse model (hepatic ischaemia/reperfusion and hepatectomy model) and isolated neutrophils from RAP1^-/- mice, the expression levels of NLRP3 and keratinocyte chemoattractant (KC) were significantly down-regulated in contrast to those in wild types. The levels of ALT and AST, as well as the neutrophil infiltration, were also decreased by RAP1 deficiency. In our clinical validation, intragraft KC expression was associated with NLRP3 and co-localized with RAP1 in neutrophils. Furthermore, NLRP3 inflammasomes were up-regulated by recombinant KC in the isolated neutrophils and liver of the mouse model. Our data demonstrated that NLRP3 inflammasomes, activated by the RAP1/KC axis, played a critical role in initiating inflammation during the early stage of liver graft injury. Targeting RAP1/KC/NLRP3 inflammasomes may offer a new therapeutic strategy against liver graft injury. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Serum Cytokine Levels and Their Relation to Clinical Features in Patients with Autoimmune Liver Diseases

Serum cytokine levels were explored in a combined group of patients with autoimmune liver diseases (AILDs) and separately in patients with autoimmune hepatitis (AIH) and overlap syndrome. Overall, 60 patients with AILD, among them 32 patients with AIH and 28 patients with overlap syndrome, were included in the cross-sectional study. Serum cytokine levels were measured at baseline and compared to those of 21 healthy controls. Patients with AILD had significantly higher levels of IL-6 (0.70 (range 0.17–99.86) in patients with AILD compared to 0.40 (range 0.14–2.65) in controls, p < 0.01), IL-8 (1.66 (0.45–34.58) versus 0.53 (0.35–2.38), resp., p < 0.01), and TNF-α (2.61 (0.23–120.88) versus 1.65 (0.21–7.54), resp., p < 0.01). Adjusted logistic regression analysis revealed a pronounced relation of IL-8 and AILD, 48.36 (3.63–643.60), as well as AIH, 18.54 (1.08–318.54), and overlap syndrome, 23.85 (2.37–240.23), while the associations between the level of other cytokines and AILD were assessed as nonsignificant. In the language of absolute numbers, the increase of IL-8 serum level by 1 pg/mL had increased the chance for a patient to find himself in a group of AILD by 48.36 times. Also, high IL-8 serum levels were strongly related to clinical parameters.

Novel plasma biomarkers associated with liver disease severity in adults with nonalcoholic fatty liver disease

Despite the high prevalence of nonalcoholic fatty liver disease (NAFLD), therapeutic options and noninvasive markers of disease activity and severity remain limited. We investigated the association between plasma biomarkers and liver histology in order to identify markers of disease activity and severity in patients with biopsy-proven NAFLD. Thirty-two plasma biomarkers chosen a priori as possible discriminators of NAFLD were measured in participants enrolled in the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network. Dichotomized histologic outcomes were evaluated using centrally read biopsies. Biomarkers with statistically significant associations with NAFLD histology were evaluated in multivariable models adjusted for clinical factors. Of 648 participants (74.4% white, 61.7% female, mean age 47.7 years), 58.0% had definite NASH, 55.5% had mild/no fibrosis (stage 0-1), and 44.4% had significant fibrosis (stage 2-4). Increased activated plasminogen activator inhibitor 1 had a strong association with definite NASH compared to not NASH or borderline NASH in multivariable analysis (odds ratio = 1.20, 95% confidence interval 1.08-1.34, P < 0.001). Biomarkers associated with significant fibrosis (versus mild/no fibrosis) in multivariable analysis included higher levels of interleukin-8, monocyte chemoattractant protein-1, resistin, soluble interleukin-1 receptor I, soluble interleukin-2 receptor alpha, and tumor necrosis factor alpha and lower levels of insulin-like growth factor 2.

CONCLUSIONS

Specific plasma biomarkers are significantly associated with disease activity and severity of fibrosis in NAFLD and are potentially valuable tools for noninvasive stratification of patients with NAFLD and identification of targets for therapeutic intervention. (Hepatology 2017;65:65-77).

The efficacy of adalimumab in psoriatic arthritis concomitant to overlapping primary biliary cholangitis and primary sclerosing cholangitis: a case report

BACKGROUND

The overlap syndrome of primary biliary cholangitis (formerly called primary biliary cirrhosis) and primary sclerosing cholangitis is an extremely rare condition that has never been described in association with other immune-mediated diseases, including psoriatic arthritis. While treatment with anti-Tumour Necrosis Factor-alpha (TNF-α) agents has proved to be effective in inflammatory arthropathies such as psoriatic arthritis, they have been employed in only a limited number of patients with autoimmune hepatitis, and their effectiveness is unclear.

CASE PRESENTATION

We report the case of a 51-year-old female affected with psoriatic arthritis concomitant to overlapping primary biliary cholangitis and primary sclerosing cholangitis in whom 28 months of adalimumab treatment improved the symptoms of the inflammatory arthropathy as well as those of both cholangiopathies.

CONCLUSION

Our results suggest that further studies examining the therapeutic role of this particular TNF-α blocker are warranted in cholestatic autoimmune hepatitis patients, and in particular in those individuals in whom the disease is associated with inflammatory arthropathies.

Novel relationships of markers of monocyte activation and endothelial dysfunction with pulmonary dysfunction in HIV-infected persons

OBJECTIVE

Chronic obstructive pulmonary disease is a common comorbidity in HIV, with prevalence and severity of disease incompletely explained by risk factors such as smoking and age. Unique HIV-associated factors, including microbial translocation, monocyte activation, and endothelial dysfunction, have been described in other comorbidities, but have not been investigated in relation to pulmonary abnormalities in HIV. This study assessed the relationship of these pathologic processes to pulmonary function in HIV-infected and uninfected individuals and determined if relationships were unique to HIV.

DESIGN

Longitudinal observational study.

METHODS

Total 274 participants completed pulmonary function testing. Markers of inflammation (IL-6, IL-8, and TNFα), microbial translocation (lipopolysaccharide, sCD14), monocyte activation (sCD163, sCD14, and IL-2 receptor), and endothelial dysfunction (endothelin-1) were measured at baseline. Cross-sectional and longitudinal analyses were performed, adjusting for pertinent covariates.

RESULTS

In HIV-infected individuals, higher IL-6 and endothelin-1 associated with worse forced expiratory volume in one second (FEV1) percentage-predicted, and higher sCD163 associated with worse FEV1/forced vital capacity. IL-6, TNFα, lipopolysaccharide, sCD163, IL-2 receptor, and endothelin-1 associated with diffusing impairment. sCD163 and endothelin-1 interacted with HIV status in relationship to pulmonary function. In HIV-infected individuals only, baseline endothelin-1 was associated with lower FEV1, and sCD163 and endothelin-1 were associated with lower diffusing capacity during follow-up.

CONCLUSION

Circulating markers of HIV-associated humoral abnormalities are associated with airflow obstruction and diffusing impairment and baseline measures of monocyte activation and endothelial dysfunction associate with lower pulmonary function over time in HIV-infected persons. These findings suggest mechanisms of the disproportionate burden of chronic obstructive pulmonary disease in HIV-infected persons.

Polysomnographic correlates of inflammatory complement components in young healthy males

A growing body of evidence has delineated the predominant role of humoral mediators of inflammation in linking sleep with immunity. Nonetheless, characterization of the relationship between complement components with inflammatory functions and objective sleep measures has not been performed. In this study we investigated the relationships between objective measures of sleep and complement components with inflammatory functions. Thirty-six healthy male university students (age, 23.94±4.23 years; BMI, 23.44±2.67 kg/m(2)) completed the study. An RMS Quest 32 polysomnograph (PSG) was used for sleep recording. Non-fasting blood was collected before subjects went to bed on the second night in the sleep laboratory to estimate complement component 3 (C-3), complement component 4 (C-4), complement factor-H (Factor-H), C1-inhibitor (C1INH), complement factor I (CFI) and other inflammatory mediators, such as IL-6 and sICAM-1. Multiple linear regression analysis was used to assess the association between PSG sleep measures and inflammatory mediators. Higher values of C-3 and lower values of sICAM-1, C1INH, and CFI (adjusted model, R2=0.211, p<0.041) predicted longer sleep duration. Lower C-3 (adjusted model, R2=0.078, p<0.055) predicted higher N1 (%). Higher levels of C1INH and CFI and lower values of C-4 (model adjusted R2=0.269, p<0.008) predicted higher N3 (%). Higher C-3, higher C-4, lower IL-6, lower C1INH and lower CFI (model adjusted R2=0.296, p<0.007) predicted higher REM (%). Poor sleep measures were associated with increased levels of pro-inflammatory complement components and decreased anti-inflammatory complement components.

Effects of tanshinone IIA on fibrosis in a rat model of cirrhosis through heme oxygenase-1, inflammation, oxidative stress and apoptosis

Tanshinone IIA is extracted from the root of Salvia miltiorrhiza and used in traditional Chinese medicine for its anti-inflammatory activity and antioxidant effects. The aim of the present study was to investigate the potential protective effects of tanshinone IIA against fibrosis in a rat model of cirrhosis and to elucidate the underlying mechanisms. Male Sprague Dawley rats were used as the model of cirrhosis in the present study. In the cirrhotic rats, the extent of fibrosis, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), heme oxygenase-1 (HO-1) protein expression, serum levels of nuclear factor (NF)-κB, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX), and the protein expression levels of phosphorylated-p38 mitogen-activated protein kinase (MAPK) were all significantly increased. However, the serum malondialdehyde (MDA) activity and protein kinase B (Akt) protein expression were suppressed in cirrhotic rats compared with the sham (control) group. Compared with the cirrhotic group, administration of tanshinone IIA reduced the extent of fibrosis, levels of ALT and AST, HO-1 protein expression, serum NF-κB, TNF-α, IL-1β and IL-6 levels, and the activity of SOD, CAT and GSH-PX. Furthermore, administration of tanshinone IIA significantly increased the inhibition of the serum MDA activity and the Akt protein expression in cirrhotic rats compared with those in the cirrhotic group. The protective effect of tanshinone IIA suppresses fibrosis in a rat model of cirrhosis, and reduces inflammation and oxidative stress, via the HO-1, Akt and p38 MAPK signaling pathway.

The coexistence of Sjögren's syndrome and primary biliary cirrhosis: a comprehensive review

Organ-specific and systemic autoimmune diseases share numerous features and often coexist in the same patient. Autoimmune cholangitis/primary biliary cirrhosis and Sjogren syndrome represent paradigmatic examples of the common grounds of different autoimmunity phenotypes based on similarities in clinical manifestations and immunopathogenesis. In fact, primary biliary cirrhosis and Sjogren's syndrome have both been coined as an autoimmune epithelitis in which apoptosis may be in both cases the key element to explain the organ-specific immune-mediated injury against the biliary and exocrine gland epithelia, respectively. Further, growing evidence supports in both diseases the view that B cells, T cytotoxic cells, and T helper cells are involved in chronic inflammation, likely via the altered expression of pro-inflammatory cytokines. The presence of estrogen receptors on the biliary and exocrine gland epithelia has been advocated as a key to the female predominance encountered in primary biliary cirrhosis and Sjogren's syndrome. Sadly, despite available data, therapeutic approaches remain largely unsatisfactory and recent studies with mechanistic approaches (as in the case of B cell depletion with rituximab) have been of partial benefit only. Future studies should focus on new molecular tools (single-cell transcriptomics, microRNA, epigenetics) to provide unique insights into common mechanisms.

Selected Cytokines Serve as Potential Biomarkers for Predicting Liver Inflammation and Fibrosis in Chronic Hepatitis B Patients With Normal to Mildly Elevated Aminotransferases

Previous studies of small cohorts have implicated several circulating cytokines with progression of chronic hepatitis B (CHB). However, to date there have been no reliable biomarkers for assessing histological liver damage in CHB patients with normal or mildly elevated alanine aminotransferase (ALT). The aim of the present study was to investigate the association between circulating cytokines and histological liver damage in a large cohort. Also, this study was designed to assess the utility of circulating cytokines in diagnosing liver inflammation and fibrosis in CHB patients with ALT less than 2 times the upper limit of normal range (ULN). A total of 227 CHB patients were prospectively enrolled. All patients underwent liver biopsy and staging by Ishak system. Patients with at least moderate inflammation showed significantly higher levels of CXCL-11, CXCL-10, and interleukin (IL)-2 receptor (R) than patients with less than moderate inflammation (P < 0.001). Patients with significant fibrosis had higher levels of IL-8 (P = 0.027), transforming growth factor alpha (TGF-α) (P = 0.011), IL-2R (P = 0.002), and CXCL-11 (P = 0.032) than the group without significant fibrosis. In addition, 31.8% and 29.1% of 151 patients with ALT < 2 × ULN had at least moderate inflammation and significant fibrosis, respectively. Multivariate analysis demonstrated that CXCL-11 was independently associated with at least moderate inflammation, and TGF-α and IL-2R independently correlated with significant fibrosis in patients with ALT < 2 × ULN. Based on certain cytokines and clinical parameters, an inflammation-index and fib-index were developed, which showed areas under the receiver operating characteristics curve (AUROC) of 0.75 (95% CI 0.66-0.84) for at least moderate inflammation and 0.82 (95% CI 0.75-0.90) for significant fibrosis, correspondingly. Compared to existing scores, fib-index was significantly superior to aspartate aminotransferase (AST) to platelet ratio index (APRI) and FIB-4 score for significant fibrosis. In conclusion, CXCL-11 was independently associated with at least moderate inflammation, whereas IL-2R and TGF-α were independent indicators of significant fibrosis in both, total CHB patients and patients with normal or mildly elevated ALT. An IL-2R and TGF-α based score (fib-index) was superior to APRI and FIB-4 for the diagnosis of significant fibrosis in patients with normal or mildly elevated ALT.

Vitamin D in primary biliary cirrhosis, a plausible marker of advanced disease

Vitamin D immune-modulating effects were extensively studied, and low levels have been linked with autoimmune diseases. The associations of vitamin D with autoimmune diseases of the liver, and particularly primary biliary cirrhosis (PBC), are yet to be defined. Hence, in this study, serum levels of vitamin D were determined in 79 patients with PBC and 70 age- and sex-matched controls by the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). Clinical and serological parameters of patients were analyzed with respect to vitamin D status. Mean levels of vitamin D were significantly lower among patients with PBC compared with controls (16.8 ± 9 vs. 22.1 ± 9 ng/ml; p = 0.029), and vitamin D deficiency (≤10 ng/ml) was documented in 33% of patients with PBC versus 7% of controls (p < 0.0001). Vitamin D levels inversely correlated with advanced liver damage and the presence of concomitant autoimmune diseases. In contrast, higher levels of vitamin D were observed among patients with PBC treated with ursodeoxycholic acid (UDCA). In conclusion, low vitamin D levels are common among patients with PBC and correlate with advanced disease, lack of UDCA therapy and autoimmune comorbidity. This alludes to the plausible roles of vitamin D as a prognostic marker of PBC severity, and as a potential player in this disease pathogenesis. While further studies are awaited, monitoring vitamin D in patients with PBC and use of supplements may be advisable.

Tumour necrosis factor alpha (TNF-α) genetic polymorphisms and the risk of autoimmune liver disease: a meta-analysis

Epidemiological studies have evaluated the association between tumour necrosis factor alpha (TNF-α)- 308G/A and (TNF-α)- 238G/A polymorphisms, and the risk of autoimmune liver disease (AILD), yet the results are conflicting. To derive a more precise estimation of the relationship, we performed this meta-analysis. A systematic review was conducted to identify all eligible studies of TNF-α polymorphisms and AILD risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between the two TNF-α polymorphisms and AILD risk. A total of 15 eligible studies were identified. Overall, positive associations of -308G/A polymorphism with AILD risk were found (A vs G allele: OR =1.45, 95%CI = 1.13- 1.86; AA vs GG: OR = 2.74, 95%CI = 1.51- 4.96; GA vs GG: OR = 1.46, 95%CI = 1.11- 1.92;dominant model: OR = 1.57, 95%CI = 1.18- 2.10; recessive model: OR = 2.22, 95%CI = 1.31- 3.76). In subgroup analysis by ethnicity, a significantly higher risk was found in Caucasians. In subgroup analysis by AILD category, significant association was observed in autoimmune hepatitis and primary sclerosing cholangitis, especially in Caucasians. Patients carrying TNF-α-238A allele had a slightly decreased risk of developing AILD (OR = 0.65, 95%CI = 0.48- 0.87). However, we found both TNF-α polymorphisms were not associated with primary biliary cirrhosis risk, even in subgroup analysis. Our meta-analysis suggests that the TNF-α-308G/A and -238G/A polymorphisms may contribute to AILD susceptibility in Caucasians,especially for autoimmune hepatitis and primary sclerosing cholangitis. Nevertheless, we found both TNF-α polymorphisms were unlikely to be associated with the risk of primary biliary cirrhosis

Tracing environmental markers of autoimmunity: introducing the infectome

We recently introduced the concept of the infectome as a means of studying all infectious factors which contribute to the development of autoimmune disease. It forms the infectious part of the exposome, which collates all environmental factors contributing to the development of disease and studies the sum total of burden which leads to the loss of adaptive mechanisms in the body. These studies complement genome-wide association studies, which establish the genetic predisposition to disease. The infectome is a component which spans the whole life and may begin at the earliest stages right up to the time when the first symptoms manifest, and may thus contribute to the understanding of the pathogenesis of autoimmunity at the prodromal/asymptomatic stages. We provide practical examples and research tools as to how we can investigate disease-specific infectomes, using laboratory approaches employed from projects studying the “immunome” and “microbiome”. It is envisioned that an understanding of the infectome and the environmental factors that affect it will allow for earlier patient-specific intervention by clinicians, through the possible treatment of infectious agents as well as other compounding factors, and hence slowing or preventing disease development.

TRAF1-C5 affects quality of life in patients with primary biliary cirrhosis

BACKGROUND

Previous studies reported associations between specific alleles of non-HLA immunoregulatory genes and higher fatigue scores in patients with primary biliary cirrhosis (PBC).

AIM

To study the relationship between variables of health-related quality of life (HRQoL) and single nucleotide polymorphisms of TRAF1-C5, a member of the tumor necrosis factor receptor family.

PATIENTS AND METHODS

TRAF1-C5 gene polymorphisms, rs2900180 and rs3761847, were analysed in 120 Caucasian PBCs. The HRQoL was assessed with SF-36, PBC-40, and PBC-27 questionnaires.

RESULTS

We found a negative association between TT genotype of rs2900180 and SF-36's domains vitality (P < 0.05), mental health (P < 0.05), and mental component summary score (P < 0.05). GG homozygotes of rs3761847 had lower vitality (P < 0.05), mental health (P < 0.05), mental component summary score (P < 0.05) and impairment of social functioning (P < 0.01). Allelic analysis has shown that T allele of rs2900180 and G allele of rs3761847 related to SF-36's vitality (P < 0.05 and P < 0.01), social functioning (P < 0.05 and P < 0.05), mental health (P < 0.01 and P < 0.05), and mental component summary score (P < 0.01 and P < 0.05), respectively. Genotyping and allelic analysis did not reveal correlation with PBC-40 and PBC-27 domains.

CONCLUSION

The association between rs2900180 and rs3761847 polymorphisms and HRQoL variables indicates that TRAF1 is involved in the induction of impaired QoL in PBC.

Age-related macular degeneration and modification of systemic complement factor H production through liver transplantation

PURPOSE

To investigate whether modification of liver complement factor H (CFH) production, by alteration of liver CFH Y402H genotype through liver transplantation (LT), influences the development of age-related macular degeneration (AMD).

DESIGN

Multicenter, cross-sectional study.

PARTICIPANTS

We recruited 223 Western European patients ≥ 55 years old who had undergone LT ≥ 5 years previously.

METHODS

We determined AMD status using a standard grading system. Recipient CFH Y402H genotype was obtained from DNA extracted from recipient blood samples. Donor CFH Y402H genotype was inferred from recipient plasma CFH Y402H protein allotype, measured using enzyme-linked immunosorbent assays. This approach was verified by genotyping donor tissue from a subgroup of patients. Systemic complement activity was ascertained by measuring levels of plasma complement proteins using an enzyme-linked immunosorbent assay, including substrates (C3, C4), activation products (C3a, C4a, and terminal complement complex), and regulators (total CFH, C1 inhibitor).

MAIN OUTCOME MEASURES

We evaluated AMD status and recipient and donor CFH Y402H genotype.

RESULTS

In LT patients, AMD was associated with recipient CFH Y402H genotype (P = 0.036; odds ratio [OR], 1.6; 95% confidence interval [CI], 1.0-2.4) but not with donor CFH Y402H genotype (P = 0.626), after controlling for age, sex, smoking status, and body mass index. Recipient plasma CFH Y402H protein allotype predicted donor CFH Y402H genotype with 100% accuracy (n = 49). Plasma complement protein or activation product levels were similar in LT patients with and without AMD. Compared with previously reported prevalence figures (Rotterdam Study), LT patients demonstrated a high prevalence of both AMD (64.6% vs 37.1%; OR, 3.09; P<0.001) and the CFH Y402H sequence variation (41.9% vs 36.2%; OR, 1.27; P = 0.014).

CONCLUSIONS

Presence of AMD is not associated with modification of hepatic CFH production. In addition, AMD is not associated with systemic complement activity in LT patients. These findings suggest that local intraocular complement activity is of greater importance in AMD pathogenesis. The high AMD prevalence observed in LT patients may be associated with the increased frequency of the CFH Y402H sequence variation.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Potentiation of the transient receptor potential vanilloid 1 channel contributes to pruritogenesis in a rat model of liver disease

Persistent pruritus is a common disabling dermatologic symptom associated with different etiologic factors. These include primary skin conditions, as well as neuropathic, psychogenic, or systemic disorders like chronic liver disease. Defective clearance of potential pruritogenic substances that activate itch-specific neurons innervating the skin is thought to contribute to cholestatic pruritus. However, because the underlying disease-specific pruritogens and itch-specific neuronal pathways and mechanism(s) are unknown, symptomatic therapeutic intervention often leads to no or only limited success. In the current study, we aimed to first validate rats with bile duct ligation (BDL) as a model for hepatic pruritus and then to evaluate the contribution of inflammation, peripheral neuronal sensitization, and specific signaling pathways and subpopulations of itch-responsive neurons to scratching behavior and thermal hypersensitivity. Chronic BDL rats displayed enhanced scratching behavior and thermal hyperalgesia indicative of peripheral neuroinflammation. BDL-induced itch and hypersensitivity involved a minor contribution of histaminergic/serotonergic receptors, but significant activation of protein-activated receptor 2 (PAR2) receptors, prostaglandin PGE2 formation, and potentiation of transient receptor potential vanilloid 1 (TRPV1) channel activity. The sensitization of dorsal root ganglion nociceptors in BDL rats was associated with increased surface expression of PAR2 and TRPV1 proteins and an increase in the number of PAR2- and TRPV1-expressing peptidergic neurons together with a shift of TRPV1 receptor expression to medium sized dorsal root ganglion neurons. These results suggest that pruritus and hyperalgesia in chronic cholestatic BDL rats are associated with neuroinflammation and involve PAR2-induced TRPV1 sensitization. Thus, pharmacological modulation of PAR2 and/or TRPV1 may be a valuable therapeutic approach for patients with chronic liver pruritus refractory to conventional treatments.

Infectome: a platform to trace infectious triggers of autoimmunity

The "exposome" is a term recently used to describe all environmental factors, both exogenous and endogenous, which we are exposed to in a lifetime. It represents an important tool in the study of autoimmunity, complementing classical immunological research tools and cutting-edge genome wide association studies (GWAS). Recently, environmental wide association studies (EWAS) investigated the effect of environment in the development of diseases. Environmental triggers are largely subdivided into infectious and non-infectious agents. In this review, we introduce the concept of the "infectome", which is the part of the exposome referring to the collection of an individual's exposures to infectious agents. The infectome directly relates to geoepidemiological, serological and molecular evidence of the co-occurrence of several infectious agents associated with autoimmune diseases that may provide hints for the triggering factors responsible for the pathogenesis of autoimmunity. We discuss the implications that the investigation of the infectome may have for the understanding of microbial/host interactions in autoimmune diseases with long, pre-clinical phases. It may also contribute to the concept of the human body as a superorganism where the microbiome is part of the whole organism, as can be seen with mitochondria which existed as microbes prior to becoming organelles in eukaryotic cells of multicellular organisms over time. A similar argument can now be made in regard to normal intestinal flora, living in symbiosis within the host. We also provide practical examples as to how we can characterise and measure the totality of a disease-specific infectome, based on the experimental approaches employed from the "immunome" and "microbiome" projects.

Bisphosphonates: focus on inflammation and bone loss

Bisphosphonates are pharmacological compounds that have been used for the prevention and treatment of several pathological conditions including osteoporosis, primary hyperparathyroidism, osteogenesis imperfecta, and other conditions characterized by bone fragility. Many studies have been performed to date to analyze their effects on inflammation and bone remodelling and related pathologies. The aim of this review is, starting from a background on inflammatory processes and bone remodelling, to give an update on the use of bisphosphonates, outlining the possible side effects and proposing new trends for the future. Starting from a brief introduction on inflammation and bone remodelling, we collect and analyze studies involving the use of bisphosphonates for treatment of inflammatory conditions and pathologies characterized by bone loss. Selected articles, including reviews, published between 1976 and 2011, were chosen from Pubmed/Medline on the basis of their content. Bisphosphonates exert a selective activity on inflammation and bone remodelling and related pathologies, which are characterized by an excess in bone resorption. They improve not only skeletal defects, but also general symptoms. Bisphosphonates have found clinical application preventing and treating osteoporosis, osteitis deformans (Paget's disease of bone), bone metastasis (with or without hypercalcaemia), multiple myeloma, primary hyperparathyroidism, osteogenesis imperfecta, and other conditions that feature bone fragility. Further clinical studies involving larger cohorts are needed to optimize the dosage and length of therapy for each of these agents in each clinical field in order to be able to maximize their properties concerning modulation of inflammation and bone remodelling. In the near future, although "old" bisphosphonates will reach the end of their patent life, "new" bisphosphonates will be designed to specifically target a pathological condition.

Inflammasomes in liver diseases

Inflammation is a common element in the pathogenesis of most chronic liver diseases that lead to fibrosis and cirrhosis. Inflammation is characterized by activation of innate immune cells and production of pro-inflammatory cytokines IL-1α, IL-1β, and TNFα. Inflammasomes are intracellular multiprotein complexes expressed in both parenchymal and non-parenchymal cells of the liver that in response to cellular danger signals activate caspase-1, and release IL-1β and IL-18. The importance of inflammasome activation in various forms of liver diseases in relation to liver damage, steatosis, inflammation and fibrosis is discussed in this review.

Epitope-specific anti-nuclear antibodies are expressed in a mouse model of primary biliary cirrhosis and are cytokine-dependent

Although the hallmark of primary biliary cirrhosis (PBC) is the presence of anti-mitochondrial antibodies (AMA), a significant number of patients have anti-nuclear antibodies (ANA) directed primarily against two nuclear proteins, gp210 and sp100. In PBC, there are considerable data on the specificity of these anti-nuclear antibodies as well as suggestive evidence that antibodies to gp210 predict a poor outcome. However, a further understanding of the significance of these autoantibodies has been hampered by limitations in accessing human subjects in a preclinical or early asymptomatic stage. To overcome this limitation, we have taken advantage of transgenic mice with abrogated transforming growth factor-β signalling in T cells (dnTGF-βRII) that develop histological features of PBC as well as the same AMA specificity. We studied these mice for serum ANA, including specific autoantibodies against gp210 and sp100. We further examined sera from dnTGF-βRII mice with concurrent deletions of the genes encoding interleukin (IL)-12p35, IL-12p40, IL-23p19, IL-17, IL-6, interferon (IFN)-γ or tumour necrosis factor (TNF)-α. Sera from all the dnTGF-βRII mouse lines contained antibodies against gp210 and sp100. Of significance, mice with germline deletions of the genes encoding IL-12p40, IL-23p19, IL-17, IL-6 and TNF-α had significantly lower titres of anti-gp210 antibodies. These results provide a platform to dissect the mechanisms of gp210 and sp100 autoantibody production in dnTGF-βRII mice as well as to study the possible role of ANA in the pathophysiology of PBC.

Primary biliary cirrhosis: a multi-faced interactive disease involving genetics, environment and the immune response

Primary biliary cirrhosis (PBC) is considered a model autoimmune disease based on several features, including the presence of a highly directed and very specific immune response to mitochondrial autoantigens, a female predominance, a targeted destruction of the biliary epithelium, and homogeneity between patients. It is essentially a chronic progressive cholestatic liver disease characterized by immune-mediated destruction of small- and medium-sized intrahepatic bile ducts. There is considerable variation in the incidence and prevalence of the disease between regions of the world, although such differences likely reflect not only a true disparity in disease but also differences in awareness; for example, in the United States, PBC is often detected in an asymptomatic stage based on multi-phasic clinical testing. There has been considerable progress at defining the immune response in this disease, including quantitation of autoreactive T cells against PDC-E2, the major mitochondrial autoantigen. The overwhelming data suggests that patients develop PBC based on a genetic predisposition and loss of tolerance to one or more environmental agents. In this review, we will present an updated overview of PBC and place it in the context of autoimmunity.

Elevated circulating soluble interleukin-2 receptor in patients with chronic liver diseases is associated with non-classical monocytes

BACKGROUND

The soluble interleukin-2 receptor (sIL-2R, sIL2R, sTAC, sCD25) is a reliable biomarker for disease activity in inflammatory disorders such as sarcoidosis. Based on the essential pathogenic role of inflammation for progression of liver diseases, we hypothesized that sIL-2R might be an indicator of inflammatory cell activation and disease severity in patients with chronic liver diseases (CLD).

METHODS

We measured sIL-2R serum levels in 71 patients with different stages and etiologies of CLD in comparison to 41 healthy controls. Serum sIL-2R concentrations were correlated with laboratory markers of liver diseases, cytokine / chemokine levels and circulating immune cell subpopulations as simultaneously assessed by FACS analysis from peripheral leukocytes.

RESULTS

CLD patients showed significantly elevated serum sIL-2R levels compared with controls. sIL-2R was significantly higher in patients with compared to patients without established liver cirrhosis and increased with the Child-Pugh stage of cirrhosis, independent of the underlying etiology. sIL-2R levels correlated inversely with parameters indicating the hepatic biosynthetic capacity, such as albumin or international normalized ratio, and positively with non-invasive markers of liver fibrosis such as hyaluronic acid or procollagen-III-peptide. Circulating immune cells might represent a major source of sIL-2R. In fact, sIL2-R levels correlated closely with circulating monocytes, especially non-classical CD14+ CD16+ monocytes, which were found to express high levels of CD25 by FACS. Pro-inflammatory cytokines, including IL-2, IFNγ or IL-6, and chemokines were also associated with sIL2-R. In addition, renal failure was an important confounder of sIL-2R levels independent of liver dysfunction and inflammation.

CONCLUSIONS

sIL-2R is elevated in patients with liver diseases and cirrhosis, is associated with circulating inflammatory cells and is increased in concomitant renal failure. These data indicate that sIL-2R might be a potential marker for immune cell activation in CLD, especially for proinflammatory and profibrogenic non-classical CD14 + CD16+ monocytes.

Changes of gut bacteria and immune parameters in liver transplant recipients

BACKGROUND

Liver transplantation is one of the most effective therapeutic options for patients with end-stage liver diseases, and gut microbiota is actively involved in potential infections in pretransplant and posttransplant patients. However, the diversity of gut microbiota and its relationship with the immune parameter of liver transplantation recipients are not well understood.

METHODS

We collected fresh feces and blood samples from 190 participants in China from November 2004 to May 2008, including 28 healthy volunteers, 51 cirrhotic patients and 111 liver-transplanted patients. Six interesting gut bacteria, plasma endotoxin, serum cytokines (i.e., tumor necrosis factor alpha and interleukin-6) and fecal secretory IgA (SIgA) were investigated by real-time quantitative PCR, chromogenic limulus amoebocyte assay, sandwich-type enzyme-linked immunosorbent assay and radioimmunoassay, respectively.

RESULTS

All Eubacteria, Bifidobacterium spp., Faecalibacterium prausnitzii and Lactobacillus spp. were significantly lower in the liver transplantation recipients while Enterobacteriaceae and Enterococcus spp. were significantly higher (P<0.05). Except for Enterococcus spp., other bacteria showed a tendency to restore to normal level along with the time after liver transplantation. Plasma endotoxin, interleukin-6 and fecal SIgA in cirrhotic patients increased significantly, but not in liver transplantation recipients. Plasma endotoxin and interleukin-6 were negatively correlated with all Eubacteria and the Bacteroides-Prevotella group, while tumor necrosis factor alpha was not significantly correlated with these six gut bacteria in cirrhotic patients.

CONCLUSIONS

Our study demonstrates that abundant gut bacteria were altered significantly in both cirrhotic and liver transplantation patients, while plasma endotoxin and interleukin-6 increased remarkably in cirrhotic patients, showing significant correlations with gut microbiota. Interestingly, our data show a tendency for these gut bacteria to restore to normal levels in liver transplantation recipients.

Liver-brain inflammation axis

It is becoming increasingly evident that peripheral organ-centered inflammatory diseases, including chronic inflammatory liver diseases, are associated with changes in central neural transmission that result in alterations in behavior. These behavioral changes include sickness behaviors, such as fatigue, cognitive dysfunction, mood disorders, and sleep disturbances. While such behaviors have a significant impact on quality of life, the changes within the brain and the communication pathways between the liver and the brain that give rise to changes in central neural activity are not fully understood. Traditionally, neural and humoral communication pathways have been described, with the three cytokines TNFα, IL-1β, and IL-6 receiving the most attention in mediating communication between the periphery and the brain, in the setting of peripheral inflammation. However, more recently, we described an immune-mediated communication pathway in experimentally induced liver inflammation whereby, in response to activation of resident immune cells in the brain (i.e., the microglia), peripheral circulating monocytes transmigrate into the brain, leading to development of sickness behaviors. These signaling pathways drive changes in behavior by altering central neurotransmitter systems. Specifically, changes in serotonergic and corticotropin-releasing hormone neurotransmission have been demonstrated and implicated in liver inflammation-associated sickness behaviors. Understanding how the liver communicates with the brain in the setting of chronic inflammatory liver diseases will help delineate novel therapeutic targets that can reduce the burden of symptoms in patients with liver disease.

Electrophile-modified lipoic derivatives of PDC-E2 elicits anti-mitochondrial antibody reactivity

Our laboratory has hypothesized that xenobiotic modification of the native lipoyl moiety of the major mitochondrial autoantigen, the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2), may lead to loss of self-tolerance in primary biliary cirrhosis (PBC). This thesis is based on the finding of readily detectable levels of immunoreactivity of PBC sera against extensive panels of protein microarrays containing mimics of the inner lipoyl domain of PDC-E2 and subsequent quantitative structure-activity relationships (QSARs). Importantly, we have demonstrated that murine immunization with one such mimic, 2-octynoic acid coupled to bovine serum albumin (BSA), induces anti-mitochondrial antibodies (AMAs) and cholangitis. Based upon these data, we have focused on covalent modifications of the lipoic acid disulfide ring and subsequent analysis of such xenobiotics coupled to a 15mer of PDC-E2 for immunoreactivity against a broad panel of sera from patients with PBC and controls. Our results demonstrate that AMA-positive PBC sera demonstrate marked reactivity against 6,8-bis(acetylthio)octanoic acid, implying that chemical modification of the lipoyl ring, i.e. disruption of the S-S disulfide, renders lipoic acid to its reduced form that will promote xenobiotic modification. This observation is particularly significant in light of the function of the lipoyl moiety in electron transport of which the catalytic disulfide constantly opens and closes and, thus, raises the intriguing thesis that common electrophilic agents, i.e. acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), may lead to xenobiotic modification in genetically susceptible individuals that results in the generation of AMAs and ultimately clinical PBC.