Protective effect of quercetin against macrophage-mediated hepatocyte injury via anti-inflammation, anti-apoptosis and inhibition of ferroptosis.

Yinchenhao Decoction (YCHD) is a classic prescription in traditional Chinese medicine (TCM). It appears to play an important role in anti-inflammation and autoimmunity protection. As one of the key active ingredients in YCHD, quercetin is a novel anti-inflammatory metabolite that exerts protective effects in many autoimmune diseases. However, its role in autoimmune hepatitis (AIH)-related hepatic injury has not been studied. The aim of this study was to reveal the hepatocyte protective mechanism of quercetin. In this study, we used Concanavalin A (Con A) to establish an in vitro hepatocyte injury-associated AIH model. Brl3a hepatocyte injury was induced by the supernatant of J774A.1 cells treated with Con A. We found that quercetin mitigated Con A-induced via macrophage-mediated Brl3a hepatocyte injury. Quercetin administration reduced the levels of alanine transaminase (ALT) and aspartate transaminase (AST) in the supernatant of Con A-treated Brl3a cells and attenuated the infiltration of J774A.1 macrophages induced by Con A. Moreover, quercetin effectively inhibited the expression of proinflammatory cytokines including interleukin-1ß (IL-1ß) by Con A. Furthermore, quercetin decreased hepatocyte apoptosis and ferroptosis levels in the macrophage-induced hepatocyte injury model. In conclusion, our study indicates that quercetin alleviates macrophage-induced hepatocyte damage by reducing the inflammatory response, apoptosis and ferroptosis. Our work suggests that quercetin might be a potential therapeutic strategy for AIH.

Toosendanin inhibits T-cell proliferation through the P38 MAPK signalling pathway.

In recent years, immunosuppressants have shown significant success in the treatment of autoimmune diseases. Therefore, there is an urgent need to develop additional immunosuppressants that offer more options for patients. Toosendanin has been shown to have immunosuppressive activity in vitro as well as effects on autoimmune hepatitis (AIH) in vivo. Toosendanin did not induce apoptosis in activated T-cells and affect the survival rate of naive T-cells. Toosendanin did not affect the expression of CD25 or secretion of IL-2 by activated T-cells, and not affect the expression of IL-4 and INF-γ. Toosendanin did not affect the phosphorylation of STAT5, ERK, AKT, P70S6K. However, toosendanin inhibited proliferation of anti-CD3/anti-CD28 mAbs-activated T-cells with IC50 of (10 ± 2.02) nM. Toosendanin arrested the cell cycle in the G0/G1 phase, significantly inhibited IL-6 and IL-17A secretion, promoted IL-10 expression, and inhibited the P38 MAPK pathway. Finally, toosendanin significantly alleviated ConA-induced AIH in mice. In Summary, toosendanin exhibited immunosuppressive activity in vivo and in vitro. Toosendanin inhibits the proliferation of activated T-cells through the P38 MAPK signalling pathway, significantly suppresses the expression of inflammatory factors, enhances the expression of anti-inflammatory factors, and effectively alleviates ConA-induced AIH in mice, suggesting that toosendanin may be a lead compound for the development of novel immunomodulatory agents with improved efficacy and reduced toxicity.

Comparison of four histological scoring systems for autoimmune hepatitis to improve diagnostic sensitivity.

BACKGROUND/AIMS: The histological criteria in the 1999 and 2008 scoring systems proposed by the International Autoimmune Hepatitis Group (IAIHG) have their inherent limitations in diagnosing autoimmune hepatitis (AIH). In this study, we evaluated the histology components of four scoring systems (1. revised original scoring system ["1999 IAIHG"], 2. simplified scoring system ["2008 IAIHG"], 3. modified histologic criteria ["2017 UCSF"], and 4. a new histologic criteria proposed by the International AIH Pathology Group ["2022 IAHPG"]) in AIH patients. METHODS: Medical records and liver biopsies were retrospectively reviewed for 68 patients from two independent medical institutions, diagnosed with AIH based on the 1999 IAIHG system between 2006 and 2016. The histological features were reviewed in detail, and the four histological scoring systems were compared. RESULTS: Out of the 68 patients, 56 (82.4%) patients met the "probable" or "definite" AIH criteria of the 2008 IAIHG system, and the proportion of histologic score 2 (maximum) was 40/68 (58.8%). By applying the 2017 UCSF criteria, the number of histology score 2 increased to 60/68 (88.2%), and "probable" or "definite" AIH cases increased to 61/68 (89.7%). Finally, applying the 2022 IAHPG histology score resulted in the highest number of cases with histologic score 2 (64/68; 94.1%) and with a diagnosis of "probable" or "definite" AIH (62/68; 91.2%). CONCLUSION: The recently proposed UCSF/IAHPG histological criteria increased the histology score of AIH. Substituting the histology component of the 2008 IAIHG system with the 2022 IAHPG criteria increased the sensitivity for diagnosing AIH (≥"Probable AIH") from 82.4% to 91.2%.

STING modulates iron metabolism to promote liver injury and inflammation in acute immune hepatitis.

The pathogenesis of Autoimmune Hepatitis (AIH) is closely associated with perturbations in iron ion metabolism, during which Stimulator of Interferon Genes (STING) plays an important role. However, the precise regulatory mechanism remains elusive. In this study, we investigated the relationship between iron dysregulation and STING activation in Concanavalin A (ConA)-induced AIH liver injury. STING knockout (STING-/-) mice and AAV (Adeno-Associated virus)-Sting1-RNAi-treated mice were involved and subjected in AIH. We observed that increased iron dysregulation was linked with STING activation, but this effect was effectively reversed by the administration of iron chelating agent Desferoxamine (DFO) and the antioxidant Ferrostatin-1 (Fer-1). Notably, the iron transport protein Transferrin (TF) and Transferrin Receptor (TfR) exhibited significant accumulation in AIH along with upregulated expression of ferritin protein. Additionally, the deficiency of STING reduced hepatic iron accumulation, mitigated oxidative stress, and attenuated macrophage activation during ConA treatment. Furthermore, liver-specific knockdown of STING using AAV-Sting1-RNAi significantly ameliorated liver iron dysregulation and oxidative stress response induced by Kupffer cells (KCs). KC-derived STING exacerbates liver damage severity in AIH through promoting disturbances in hepatic iron ion metabolism as well as oxidative stress response. These findings provide valuable insights into the pathogenesis of AIH and may pave the way for potential therapeutic strategies targeting STING and iron metabolism in the future.

Clinical and Pathological Features of Immune Checkpoint Inhibitor-induced Liver Injury in Comparison with Drug-induced Liver Injury and Autoimmune Hepatitis.

BACKGROUND AND AIMS: Immune checkpoint inhibitors may cause various types of organ damage as immune-related adverse events, of which, liver damage is the most common. Herein, we evaluated the clinicopathological features of immune checkpoint inhibitor-related liver injury and investigated the differences between immune checkpoint inhibitor-related liver injury and drug-induced liver injury or autoimmune hepatitis. METHODS: We selected patients with ≥ grade 3 liver injury who were diagnosed with immune checkpoint inhibitor-related liver injury (n=15). Liver biopsies were performed in 10 of the 15 cases. We also selected cases in which a liver biopsy was performed and drug-induced liver injury (n=7) or autoimmune hepatitis [n=21: acute exacerbation (n=13) was diagnosed and cases of acute onset (n=8), in which liver function test results corresponded to ≥ grade 3]. RESULTS: Portal fibrosis and periportal activity scores were significantly higher in the acute exacerbation autoimmune hepatitis group than in the other groups. Portal and lobular activity were not different between the groups. Plasma cell infiltration showed a higher trend in the autoimmune hepatitis group than in the other groups. Granuloma formations were seen in 90% of immune checkpoint inhibitor-related liver injury cases. The CD4/8 ratio was significantly lower in the immune checkpoint inhibitor-related liver injury group than in the other groups. Patients with bile duct injury had poorer response to corticosteroid therapy than those without. CONCLUSIONS: There are some obvious differences among immune checkpoint inhibitor-related liver injury, drug-induced liver injury, and autoimmune hepatitis in liver histology. Liver biopsy is helpful for the diagnosis and severity evaluation of liver injury.

Dextran sulfate sodium-induced gut microbiota dysbiosis aggravates liver injury in mice with S100-induced autoimmune hepatitis.

Recently, the incidence of autoimmune hepatitis (AIH) has gradually increased, and the disease can eventually develop into cirrhosis or even hepatoma if left untreated. AIH patients are often characterized by gut microbiota dysbiosis, but whether gut microbiota dysbiosis contributes to the progression of AIH remains unclear. In this study, we investigate the role of gut microbiota dysbiosis in the occurrence and development of AIH in mice with dextran sulfate sodium salt (DSS) induced colitis. C57BL/6J mice were randomly divided into normal group, S100-induced AIH group, and DSS+S100 group (1 % DSS in the drinking water), and the experimental cycle lasted for four weeks. We demonstrate that DSS administration aggravates hepatic inflammation and disruption of the intestinal barrier, and significantly changes the composition of gut microbiota in S100-induced AIH mice, which are mainly characterized by increased abundance of pathogenic bacteria and decreased abundance of beneficial bacteria. These results suggest that DSS administration aggravates liver injury of S100-induced AIH, which may be due to DSS induced gut microbiota dysbiosis, leading to disruption of the intestinal barrier, and then, the microbiota translocate to the liver, aggravating hepatic inflammation.

Sophoricoside attenuates autoimmune­mediated liver injury through the regulation of oxidative stress and the NF­κB signaling pathway.

The prevalence of autoimmune hepatitis (AIH) is increasing, yet specific pharmacotherapies remain to be explored. The present study aimed to investigate the effects of sophoricoside (SOP), a bioactive component of medical herbs, on AIH and to elucidate the underlying mechanisms. Bioinformatic approaches were used to predict the potential targets and underlying regulatory mechanisms of SOP on AIH. The effects of SOP on AIH were evaluated by determining the expression levels of inflammatory cytokines, histological liver injury and hepatic fibrosis in an improved chronic cytochrome P450 2D6 (CYP2D6)­AIH mouse model and in a model of concanavalin­A (ConA)­induced acute immune­mediated liver injury. The antioxidant activity of SOP was detected in in vivo and in vitro experiments. The selected signal targeted by SOP in AIH was further confirmed using western blot analysis and immunofluorescence staining. The results of bioinformatic analysis revealed that the targets of SOP in AIH were related to oxidative stress and the NF­κB gene set. The NF­κB transcription factor family is a key player that controls both innate and adaptive immunity. The activation of the NF­κB signaling pathway is often associated with autoimmune disorders. In the animal experiments, SOP attenuated CYP2D6/ConA­induced AIH, as evidenced by a significant reduction in the levels of hepatic enzymes in serum, inflammatory cytokine expression and histological lesions in the liver. The oxidative response in AIH was also significantly inhibited by SOP, as evidenced by a decrease in the levels of hepatic malondialdehyde, and elevations in the total antioxidant capacity and glutathione peroxidase levels. The results of the in vivo and in vitro experiments revealed that SOP significantly reduced the enhanced expression and nuclear translocation of phosphorylated p65 NF­κB in the livers of mice with AIH and in lipopolysaccharide­stimulated AML12 cells. On the whole, the present study demonstrates the protective role of SOP in AIH, which may be mediated by limiting the oxidative response and the activation of the NF­κB signaling pathway in hepatocytes.

Clinicopathologic Features of Severe Acute Hepatitis Associated With Adenovirus Infection in Children.

A recent increase in reports of severe acute hepatitis of unknown etiology in children is under investigation. Although adenovirus has been frequently detected, its role remains unclear, and systematic histopathologic analysis is lacking. We conducted a retrospective study of 11 children hospitalized between October 2021 and May 2022 with unexplained acute hepatitis and concurrent adenovirus infection. Liver biopsies collected shortly after admission demonstrated moderately to severely active hepatitis in 8/11 (73%) cases, characterized by marked portal mixed inflammation, moderate-to-severe interface activity, and milder lobular inflammation. Clusters of plasma cells were present in 6/11 (55%) cases, mimicking autoimmune hepatitis. Semiquantitative scoring of 17 discrete histologic features found that greater degrees of portal inflammation, interface activity, bile duct injury, bile ductular reaction, lobular inflammation, Kupffer cell activation, and hepatocyte focal necrosis were significantly more common in these cases in comparison to the control group of unexplained acute severe hepatitis without adenovirus infection. Liver biopsy immunohistochemistry was negative for adenovirus in all cases. Polymerase chain reaction testing of liver tissue was positive for the enteric adenovirus serotypes 41 (species F) in 10/11 (91%) cases. An immunoprofile study of hepatic infiltrating lymphocytes in 1 patient revealed the presence of large numbers of CD3 + and CD4 + lymphocytes. Nine patients received supportive treatment without steroids and recovered without the need for liver transplantation. In summary, liver injury in children with severe acute hepatitis and adenovirus infection is characterized by a hepatitic pattern that resembles severe autoimmune hepatitis and may represent an immune-mediated process associated with viral infection.

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression.

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1ß and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

Human menstrual blood-derived stem cells alleviate autoimmune hepatitis via JNK/MAPK signaling pathway in vivo and in vitro.

Autoimmune hepatitis (AIH) is a severe globally distributed liver disease that could occur at any age. Human menstrual blood-derived stem cells (MenSCs) have shown therapeutic effect in acute lung injury and liver failure. However, their role in the curative effect of AIH remains unclear. Here, a classic AIH mouse model was constructed through intravenous injection with concanavalin A (Con A). MenSCs were intravenously injected while Con A injection in the treatment groups. The results showed that the mortality by Con A injection was significantly decreased by MenSCs treatment and liver function tests and histological analysis were also ameliorated. The results of phosphoproteomic analysis and RNA-seq revealed that MenSCs improved AIH, mainly by apoptosis and c-Jun N-terminal kinase/mitogen-activated protein signaling pathways. Apoptosis analysis demonstrated that the protein expression of cleaved caspase 3 was increased by Con A injection and reduced by MenSCs transplantation, consistent with the TUNEL staining results. An AML12 co-culture system and JNK inhibitor (SP600125) were used to verify the JNK/MAPK and apoptosis signaling pathways. These findings suggested that MenSCs could be a promising strategy for AIH.

Longitudinal changes in quantitative magnetic resonance imaging metrics in children and young adults with autoimmune liver disease.

PURPOSE: To assess longitudinal changes in quantitative MRI metrics in pediatric and young adult patients with autoimmune liver disease (AILD). METHODS: This prospective, IRB-approved study included 20 children and young adults (median age = 15 years) with primary sclerosing cholangitis (PSC)/autoimmune sclerosing cholangitis (ASC) and 19 (median age = 17 years) with autoimmune hepatitis (AIH). At a field strength of 1.5-T, T2*-corrected T1 mapping (cT1), 3D fast spin-echo MRCP, and 2D gradient recalled echo MR elastography (MRE) were performed at baseline, one year, and two years. cT1 and quantitative MRCP were processed using LiverMultiScan and MRCP + , respectively (Perspectum Ltd, Oxford, UK). Linear mixed models were used to assess longitudinal changes in quantitative MRI metrics. Spearman rank-order correlation was used to assess relationships between changes in quantitative MRI metrics. RESULTS: Changes in quantitative MRI metrics greater than established repeatability coefficients were measured in six (cT1) and five (MRE) patients with PSC/ASC as well as in six patients (cT1 and MRE) with AIH, although linear mixed models identified no significant changes for the subgroups as a whole. For PSC/ASC, there were positive correlations between change in liver stiffness and changes in bile duct strictures (ρ = 0.68; p = 0.005) and bile duct dilations (ρ = 0.70; p = 0.004) between baseline and Year 2. CONCLUSION: On average, there were no significant changes in quantitative MRI metrics over a two-year period in children and young adults with AILD. However, worsening cholangiopathy was associated with increasing liver stiffness by MRE in patients with PSC/ASC.

[Epidemiology of Autoimmune Liver Disease].

Autoimmune liver disease is an important immune-mediated pathologic entity involving the liver and intrahepatic bile duct, including autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. Although it is necessary to ascertain its presence in acute or chronic liver disease without common causes, it is not easy to diagnose this disease straightforwardly because of its rarity. Recently, the incidence and prevalence of autoimmune hepatitis and primary biliary cholangitis have increased in several regions. In contrast, there is limited data dealing with the trend of the epidemiology of primary sclerosing cholangitis worldwide. Physicians should consider the epidemiologic characteristics of autoimmune liver disease because early diagnosis and proper treatment might prevent the progression of advanced liver disease. In addition, more sophisticated epidemiologic studies will be needed to elucidate the trend of these rare diseases nationwide.

[Diagnosis of Autoimmune Hepatitis].

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory liver disease with an uncertain cause. The diagnosis of AIH is based on the characteristic clinical and laboratory findings (elevated liver enzyme and hypergammaglobulinemia), the presence of characteristic autoantibodies, and compatible histological abnormalities. AIH lacks a signature diagnostic marker, and the diagnosis requires the exclusion of other diseases (viral hepatitis, alcoholic liver disease, non-alcoholic steatohepatitis, drug-induced liver injury, Wilson's disease, and hereditary hemochromatosis). Therefore, collaboration between the clinical physician, laboratory medicine experts, and pathologists is important for a diagnosis. In December 2022, the Korean Association for the Study of the Liver (KASL) clinical practice guidelines were established. This review article summarizes the diagnosis part of these guidelines.

Long-term outcomes of patients with type 1 or 2 autoimmune hepatitis presenting in childhood.

BACKGROUND & AIMS: In children with autoimmune hepatitis, uncertainties include outcomes associated with type 2 hepatitis, the possibility of and criteria for attempting withdrawal of treatment, and long-term outcomes. We report our experience on these issues. METHODS: From 1973 to 2002, 117 children with type 1 (n = 65) or type 2 (n = 52) hepatitis, excluding fulminant hepatitis, were treated, primarily with prednisone and azathioprine. Median follow-up was 20 years in survivors. RESULTS: Normalisation of aminotransferases and prothrombin ratio were observed in 93% and 84% of children, respectively; sustained remission after treatment withdrawal was recorded in 24% of the entire population, with a median follow-up of 7 years. Sustained treatment-free remission was obtained in 11 of 24 children with follow-ups of 4-22 years based on durable normalisation of aminotransferases (without histological assessment). Gastrointestinal bleeding from varices and the emergence of extrahepatic autoimmune disorders occurred in 10 and 22 patients, respectively. Liver transplantation was performed in 23 patients at a median age of 21 years. The 30-year probabilities of overall and native liver survival were 81% and 61%, respectively. No differences were observed between type 1 and 2 hepatitis for any of the component parts of outcome. In the multivariate analysis, a persistent abnormal prothrombin ratio was associated with worse probabilities of overall and native liver survival. CONCLUSIONS: In terms of liver outcome, type 2 hepatitis is not different from type 1. Withdrawal of treatment is possible without prior liver histology. A persistent abnormal prothrombin ratio identifies patients who will require liver transplantation in adolescence or early adulthood. IMPACT AND IMPLICATIONS: In children with autoimmune hepatitis, there are conflicting reports on the differences in outcome between type 1 and type 2 hepatitis, and on the possibility of treatment withdrawal, before which liver histology is required; data concerning >10-year overall and native liver survival rates are limited. In this study, we found no differences in outcomes between type 1 and 2 hepatitis; a durable treatment-free state was achieved in 19% of all patients throughout childhood and early adulthood, and in 45% of children for whom treatment withdrawal was attempted without prior liver histology; prothrombin was found to be predictive of 30-year overall and native liver survival. The results allow for a less-strict approach to treatment withdrawal in children, avoiding the risks of a liver biopsy, and they provide a tool to help anticipate the need for liver transplantation before complications occur.

Hepatic Dry Copper Weight in Pediatric Autoimmune Liver Disease.

OBJECTIVES: Elevated hepatic dry copper weight is recognized in adults with autoimmune liver disease (AILD) and chronic cholestasis. We aim to review hepatic dry copper weight in pediatric AILD. METHODS: Retrospective review of pediatric AILD managed at our institution from 1999 to 2018, and 104 patients with hepatic dry copper weight assessment were included. RESULTS: Median age at presentation was 13.4 years (interquartile range, IQR, 11.7-14.9), 60% female, 54% autoimmune hepatitis, 42% autoimmune sclerosing cholangitis, and 4% primary sclerosing cholangitis. Histological features of advanced liver fibrosis in 68%. Median hepatic dry copper weight was 51.1 µg/g dry weight (IQR, 28.0-103.8). Elevated hepatic dry copper weight (>50 µg/g dry weight) was present in 51%, and was not associated with AILD subtype ( P = 0.83), age at presentation ( P = 0.68), or advanced fibrosis ( P = 0.53). Liver transplantation (LT) was performed in 10%, who had higher hepatic dry copper weight (148.5 µg/g dry weight [IQR, 39.5-257.3] vs 47.5 [IQR, 27.8-91.5], P = 0.04); however this was not associated with LT on multivariate analysis (hazard ratio 1.002, 95% CI 0.999-1.005, P = 0.23). In 8 (7.7%) patients ATP7B was sequenced and potentially disease causing variants were identified in 2 patients, both who required LT. CONCLUSIONS: Elevations in hepatic dry copper weight are common in pediatric AILD. Unlike in adults, it is not associated with AILD subtypes with cholestasis. Higher dry copper weight was detected in patients who required LT. While further work is needed to identify the significance of copper deposition in pediatric AILD, we recommend close monitoring of patients with elevated levels for progressive liver disease.

IgG4-related autoimmune liver disease.

The term IgG4-related autoimmune liver disease (AILD) refers to hepato-biliary manifestations of Immunoglobin G4-related disease (IgG4-RD) including IgG4-related sclerosing cholangitis and IgG4-related pseudotumor. The association of some forms of autoimmune hepatitis to IgG4-RD remains controversial. Although autoimmune phenomena have not been clearly observed in IgG4-AILD, perturbation of the adaptive immune system and activation of the humoral response represent established pathophysiological hallmarks and potential therapeutic targets. Clinical manifestations of IgG4-AILD are virtually indistinguishable from bile duct cancer or primary sclerosing cholangitis and are due to mass forming lesions and thickening of the biliary tract that progressively lead to biliary ducts obstruction. There are no current reliable biomarkers for IgG4-AILD and diagnosis should rely on the integration of clinical, serological, radiological, and histological findings. In analogy to most IgG4-RD manifestations, and in contrast to its major mimickers, IgG4-AILD promptly responds to glucocorticoids but frequently relapses, thus requiring long-term maintenance therapy to avoid progressive fibrosclerotic disease and liver cirrhosis. Accumulating evidence on the efficacy of B-cell depletion therapy in patients with systemic IgG4-RD is gradually changing the treatment paradigm of IgG4-AILD and biologics will be increasingly used also for gastroenterological manifestations of IgG4-RD to spare glucocorticoids and traditional immunosuppressive agents. Looking ahead, identification of reliable biomarkers and of mini-invasive strategies to obtain informative biopsies from the biliary tree represent unavoidable priorities to optimize diagnosis and management of IgG4-AILD.