Histologically proven AMA positive primary biliary cholangitis but normal serum alkaline phosphatase: Is alkaline phosphatase truly a surrogate marker?

Evolutionary relationship between antimitochondrial antibody positivity and primary biliary cholangitis in Taiwan: a 16-year hospital cohort study

Background

How antimitochondrial antibody (AMA)-positive patients evolve to have primary biliary cholangitis (PBC) in viral hepatitis-endemic areas is unknown.

Objectives

We aimed to investigate this evolution in Taiwan.

Design/methods

A 16-year medical center-based cohort study of 2,095,628 subjects was conducted in Taiwan, an Asian country endemic to viral hepatitis. AMA-positive subjects were those with positive AMA with alkaline phosphatase (ALP) ⩽1.5 times the upper limit of normal (ULN), and PBC was defined as positive AMA with ALP >1.5 × ULN.

Results

AMA-positive subjects had a lower average age- and sex-adjusted prevalence than PBC patients (4.68/105 versus 11.61/105, p = 0.0002), but their incidence was comparable (0.99/105 versus 1.12/105, p = 0.36). The former group had a borderline significantly lower mean age (56.59 years versus 58.10 years, p = 0.06) and a lower female-to-male ratio (2.85:1 versus 5.44:1, p < 0.0001). Both AMA-positive subjects (prevalence change: 20.0%, p < 0.01; incidence change: -9.2%, p < 0.01) and PBC patients (prevalence change: 14.6%, p < 0.01; incidence change: -4.7%, p < 0.01) prevalence rate increased but the incidence rate decreased. Among the 423 AMA-positive subjects, 77 (18.2%) developed PBC, for a mean duration of 1.757 years. Compared with AMA-positive subjects, PBC patients had similar concurrent chronic hepatitis B (CHB) rates (2.7% versus 4.3%, p = 0.197) but lower chronic hepatitis C (CHC) rates (3.69% versus 15.60%, p < 0.01).

Conclusion

PBC was more prevalent than AMA-positive subjects, and PBC patients had a higher female-to-male ratio than AMA-positive subjects, of whom 18.2% developed PBC (mean lag: 1.757 years). Upward trends in prevalence rates and downward trends in incidence rates were noted for both AMA-positive subjects and PBC. CHB was rare, CHC was more prevalent among PBC patients than the general population, and CHC was less prevalent among PBC than among AMA-positive subjects.

Prevalence and significance of antimitochondrial antibodies in autoimmune hepatitis (AIH): Results from a large multicentre study of the International AIH Group

BACKGROUND & AIMS

Antimitochondrial antibodies (AMA) are specific markers for the diagnosis of primary biliary cholangitis (PBC) but can also be found occasionally in patients with autoimmune hepatitis (AIH). The present large multicentre cohort study assessed the prevalence and significance of AMA in AIH-patients.

METHODS

123 AMA-positive AIH-patients were investigated and compared with 711 age-matched AMA-negative AIH-patients and 69 patients with AIH/PBC variant.

RESULTS

AMA prevalence in AIH-patients was 5.1% (range: 1.2%-11.8%). AMA-positivity was associated with female sex (p = 0.031) in AMA-positive AIH-patients but not with liver biochemistry, bile duct injury on liver biopsy, disease severity at baseline and response to treatment compared to AMA-negative AIH-patients. Comparing AMA-positive AIH-patients to those with AIH/PBC variant, there was no difference in disease severity. Regarding liver histology, AIH/PBC variant patients were characterized by the presence of at least one feature of bile duct damage (p<0.001). Response to immunosuppressive treatment was similar among groups. From AMA-positive AIH patients only those with evidence of non-specific bile duct injury had higher risk to progress to cirrhosis (HR=4.314, 95%CI: 2.348-7.928; p<0.001). During follow-up, AMA-positive AIH-patients had higher risk to develop histological bile duct injury (HR 4.654, 95%CI 1.829-11.840; p = 0.001).

CONCLUSIONS

AMA presence is relatively common among AIH-patients, but their clinical significance seems important only when they co-exist with non-specific bile duct injury at the histological level. Therefore, a careful evaluation of liver biopsy seems of utmost importance in these patients.

Role of biochemical markers and autoantibodies in diagnosis of early-stage primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic progressive autoimmune cholestatic disease. The main target organ of PBC is the liver, and nonsuppurative inflammation of the small intrahepatic bile ducts may eventually develop into cirrhosis or liver fibrosis.

AIM

To explore the clinical characteristics of early-stage PBC, identify PBC in the early clinical stage, and promptly treat and monitor PBC.

METHODS

The data of 82 patients with PBC confirmed by pathology at Tianjin Second People's Hospital from January 2013 to November 2021 were collected, and the patients were divided into stage I, stage II, stage III, and stage IV according to the pathological stage. The general data, serum biochemistry, immunoglobulins, and autoimmune antibodies of patients in each stage were retrospectively analyzed.

RESULTS

In early-stage (stages I + II) PBC patients, 50.0% of patients had normal alanine aminotransferase (ALT) levels, and 37.5% had normal aspartate aminotransferase (AST) levels. For the remaining patients, the ALT and AST levels were mildly elevated; all of these patients had levels of < 3 times the upper limit of normal values. The AST levels were significantly different among the three groups (stages I + II vs stage III vs stage IV, P < 0.05). In the early stage, 29.2% of patients had normal alkaline phosphatase (ALP) levels. The remaining patients had different degrees of ALP elevation; 6.3% had ALP levels > 5 times the upper limit of normal value. Moreover, γ-glutamyl transferase (GGT) was more robustly elevated, as 29.2% of patients had GGT levels of > 10 times the upper limit of normal value. The ALP values among the three groups were significantly different (P < 0.05). In early stage, the jaundice index did not increase significantly, but it gradually increased with disease progression. However, the above indicators were significantly different (P < 0.05) between the early-stage group and the stage IV group. With the progression of the disease, the levels of albumin and albumin/globulin ratio tended to decrease, and the difference among the three groups was statistically significant (P < 0.05). In early-stage patients, IgM and IgG levels as well as cholesterol levels were mildly elevated, but there were no significant differences among the three groups. Triglyceride levels were normal in the early-stage group, and the differences among the three groups were statistically significant (P < 0.05). The early detection rates of anti-mitochondria antibody (AMA) and AMA-M2 were 66.7% and 45.8%, respectively. The positive rate of anti-sp100 antibodies was significantly higher in patients with stage IV PBC. When AMA and AMA-M2 were negative, in the early stage, the highest autoantibody was anti-nuclear antibody (ANA) (92.3%), and in all ANA patterns, the highest was ANA centromere (38.5%).

CONCLUSION

In early-stage PBC patients, ALT and AST levels are normal or mildly elevated, GGT and ALP levels are not elevated in parallel, GGT levels are more robustly elevated, and ALP levels are normal in some patients. When AMA and AMA-M2 are negative, ANA especially ANA centromere positivity suggests the possibility of early PBC. Therefore, in the clinic, significantly elevated GGT levels with or without normal ALP levels and with ANA (particularly ANA centromere) positivity (when AMA and AMA-M2 are negative) may indicate the possibility of early PBC.

Primary biliary cholangitis: molecular pathogenesis perspectives and therapeutic potential of natural products

Primary biliary cirrhosis (PBC) is a chronic cholestatic immune liver disease characterized by persistent cholestasis, interlobular bile duct damage, portal inflammation, liver fibrosis, eventual cirrhosis, and death. Existing clinical and animal studies have made a good progress in bile acid metabolism, intestinal flora disorder inflammatory response, bile duct cell damage, and autoimmune response mechanisms. However, the pathogenesis of PBC has not been clearly elucidated. We focus on the pathological mechanism and new drug research and development of PBC in clinical and laboratory in the recent 20 years, to discuss the latest understanding of the pathological mechanism, treatment options, and drug discovery of PBC. Current clinical treatment mode and symptomatic drug support obviously cannot meet the urgent demand of patients with PBC, especially for the patients who do not respond to the current treatment drugs. New treatment methods are urgently needed. Drug candidates targeting reported targets or signals of PBC are emerging, albeit with some success and some failure. Single-target drugs cannot achieve ideal clinical efficacy. Multitarget drugs are the trend of future research and development of PBC drugs.

Guidelines on the Diagnosis and Management of Primary Biliary Cholangitis (2021)

In 2015, the Chinese Society of Hepatology and the Chinese Society of Gastroenterology published a consensus on primary biliary cholangitis (PBC). In the past years, numerous clinical studies have been published in the field of PBC. To guide the clinical diagnosis and management of PBC patients, the Chinese Society of Hepatology invited a panel of experts to assess the new clinical evidence and formulate the current guidelines.

Clinicopathological features of 11 cases of chronic hepatitis B infection complicated with primary biliary cholangitis

BACKGROUND

Only a few cases of chronic hepatitis B (CHB) with primary biliary cholangitis (PBC) have been reported based on histological evidence from liver biopsies.

AIM

To observe the clinicopathological features and outcomes of 11 patients with CHB infection complicated by PBC.

METHODS

Eleven patients with CHB and PBC who underwent liver biopsy at the Zhenjiang Third Hospital, affiliated with Jiangsu University, and Wuxi Fifth People’s Hospital, from January 2005 to September 2020, were selected. All patients initially visited our hospital with CHB and were pathologically diagnosed with CHB and PBC.

RESULTS

Only five had elevated alkaline phosphatase levels, nine were positive for anti-mitochondrial antibody (AMA)-M2, and two were negative for AMA-M2. Two had jaundice and pruritus symptoms, 10 had mildly abnormal liver function, and one had severely elevated bilirubin and liver enzyme levels. The pathological characteristics of CHB complicated by PBC overlapped with those of PBC-autoimmune hepatitis (AIH). When necroinflammation of the portal area is not obvious, the pathological features of PBC are predominant, similar to the features of PBC alone. When the interface is severe, biliangitis will occur, with a large number of ductular reactions in zone 3. Unlike the PBC-AIH overlap pathology, this pathology is characterized by a small amount of plasma cell infiltration. Unlike PBC, lobulitis is often observed.

CONCLUSION

This is the first large case series to show that the rare pathological features of CHB with PBC are similar to those of PBC-AIH and small duct injury was observed.

Role of autoantibodies in the clinical management of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease characterized by immune-driven destruction of small intrahepatic bile ducts leading a proportion of patients to hepatic failure over the years. Diagnosis at early stages in concert with ursodeoxycholic acid treatment has been linked with prevention of disease progression in the majority of cases. Diagnosis of PBC in a patient with cholestasis relies on the detection of disease-specific autoantibodies, including anti-mitochondrial antibodies, and disease-specific anti-nuclear antibodies targeting sp100 and gp210. These autoantibodies assist the diagnosis of the disease, and are amongst few autoantibodies the presence of which is included in the diagnostic criteria of the disease. They have also become important tools evaluating disease prognosis. Herein, we summarize existing data on detection of PBC-related autoantibodies and their clinical significance. Moreover, we provide insight on novel autoantibodies and their possible prognostic role in PBC patients.

Application of the Latest Advances in Evidence-Based Medicine in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic, cholestatic, autoimmune liver disease that can progress to end-stage liver disease and its complications. A previous expert review panel collaborated on a consensus document for gastroenterologists and other healthcare professionals regarding the care of patients with PBC. Subsequently, there have been several recent important developments in the diagnosis, treatment, and monitoring of patients with PBC. These include updates to prognostic models on risk stratification, new noninvasive tools for staging of disease, updates to the appropriate use of and long-term treatment results with obeticholic acid as a second-line treatment, the emerging therapeutic role of fibrates, and the advancement of investigational agents for managing PBC. In this updated expert consensus document, we provide updates on staging, the use of noninvasive prognostic tools, and a treatment algorithm to provide evidence-based and practical tools for clinicians who manage PBC, with the ultimate goal to improve the long-term outcomes for patients with this chronic liver disease.

Contemporary Epidemiology of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a cholestatic liver disease with potential evolution to liver cirrhosis when left untreated. Despite being rare, PBC has a substantial impact on the quality of life and survival of affected patients. Women are the most diagnosed worldwide; however, male subjects seem to have more aggressive disease and worse prognosis. Changing epidemiologic trends are emerging in PBC, with increasing global prevalence and slight smoothing of sex differences. In this review we present available data on incidence rates and prevalence of PBC worldwide, highlighting geographic differences and factors impacting clinical outcomes.

The future risk of primary biliary cholangitis (PBC) is low among patients with incidental anti-mitochondrial antibodies but without baseline PBC

Anti-mitochondrial autoantibodies (AMAs) are highly specific for the diagnosis of primary biliary cholangitis (PBC) but are also occasionally found in other diseases. In the present study, we evaluated the incidence of and predictors for PBC development in AMA-positive patients with other liver or non-liver diseases at baseline. In this retrospective study, we screened patients who tested positive for AMA and/or anti-mitochondrial M2 antibody (AMA-M2) at Beijing Friendship Hospital, Capital Medical University, from October 2005 to January 2017. They were categorized by their diagnosis at the baseline as patients with PBC or non-PBC cases. We followed up on the non-PBC cases through telephone interviews and reviewing of medical records to obtain laboratory results and clinical outcomes. In total, 139 patients were AMA-positive but did not fulfill the diagnostic criteria of PBC at baseline, including 51 patients with non-PBC liver diseases and 88 cases with non-liver diseases. The titers of AMA-M2, alkaline phosphatase, gamma-glutamyl transpeptidase, and immunoglobulin M were significantly higher in patients with PBC compared to those with non-PBC liver diseases and non-liver diseases. After a median follow-up of 4.6 (interquartile range: 2.4-7.6) years, 4.3% (6 of 139) developed PBC, with an accumulative 5-year incidence rate of 4.2%. None of the patients with non-PBC liver diseases developed PBC, whereas the 5-year incidence rate of PBC was 7.8% among 88 patients with non-liver diseases. Lower alanine aminotransferase and higher immunoglobulin M were independent predictors for developing PBC. Conclusion: Our results suggest a low risk of developing PBC over time in AMA-positive patients with other liver and non-liver diseases.

Anti-mitochondrial Antibody-Negative Primary Biliary Cholangitis Is Part of the Same Spectrum of Classical Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease in which anti-mitochondrial antibodies (AMA) are the diagnostic hallmark. Whether AMA-negative PBC patients represent a different phenotype of disease is highly debated.

AIMS

The purpose of our study was to compare AMA-positive and AMA-negative PBC patients in a large non-white admixed Brazilian cohort.

METHODS

The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical features and treatment outcomes of Brazilian PBC patients, stratifying data according to AMA status.

RESULTS

A total of 464 subjects (95.4% females, mean age 56 ± 5 years) with PBC were included. Three hundred and eighty-four (83%) subjects were AMA-positive, whereas 80 (17%) had AMA-negative PBC. Subjects with AMA-negative PBC were significantly younger (52.2 ± 14 vs. 59.6 ± 11 years, p = 0.001) and had their first symptom at an earlier age (43.2 ± 13 vs. 49.5 ± 12 years, p = 0.005). Frequency of type 2 diabetes was significantly increased in subjects with AMA-negative PBC (22.5% vs. 12.2%, p = 0.03). Lower IgM (272.2 ± 183 vs. 383.2 ± 378 mg/dL, p = 0.01) and triglycerides (107.6 ± 59.8 vs.129.3 ± 75.7 mg/dL, p = 0.025) and higher bilirubin (3.8 ± 13.5 vs. 1.8 ± 3.4 mg/dL, p = 0.02) levels were also observed in this subgroup. Response to ursodeoxycholic acid varied from 40.5 to 63.3% in AMA-positive and 34 to 62.3% in AMA-negative individuals, according to different response criteria. Outcomes such as development of liver-related complications, death and requirement for liver transplantation were similar in both groups.

CONCLUSIONS

AMA-negative PBC patients are similar to their AMA-positive counterparts with subtle differences observed in clinical and laboratory features.

Clinical significance of HEp-2 cell cytoplasmic patterns in anti-neutrophil cytoplasmic antibody associated vasculitis

The study was to investigate the clinical characteristics and significance of antinuclear antibody (ANA) cytoplasmic patterns in ANCA-associated vasculitis (AAV) from Southwest China.A retrospective study including 232 AAV patients from Peoples Hospital of Deyang City was performed. These included 115 patients with ANA cytoplasmic pattern as observation group and 117 patients without ANA cytoplasmic pattern as control group.Chest involvement (60.00 vs 46.15, P = .035), cardiovascular involvement (5.21 vs 29.91, P < .001), and renal involvement (37.39 vs 77.78, P = .001) were different between groups.Total protein (69.55 vs 64.01, P < .001), triglyceride (1.41 vs 1.18, P = .023), mean cell volume (89.76 vs 87.59, P = .040), and estimated glomerular filtration rate (76.67 vs 50.87, P = .035) were higher in ANA cytoplasmic patterns group. Creatinine (73.00 vs 117.50, P = .011), white blood cell (6.93 vs 8.86, P = .001), platelet (196.0 vs 239.0, P = .017), anti-myeloperoxidase (2.44 vs 3.42, P = .042), and anti-proteinase 3 (1.00 vs 4.93, P = .007) were lower in this group. In multivariate analysis, creatinine (odds ratio [OR] = 1.21, 95% confidence interval [CI]: 1.06-1.38), triglyceride (OR = 1.97, 95% CI: 1.10-3.48), and anti-myeloperoxidase (OR = 1.64, 95% CI: 1.37-1.95) were independent risk factors of AAV renal involvement. Total protein (OR = .95, 95% CI: 0.91-0.99) was an independent protective factor of AAV renal involvement. Chi-square test showed that speckled pattern was different among anti-neutrophil cytoplasmic antibody patterns (χ2 = 18.526, P < .001).In summary, HEp-2 cell cytoplasmic patterns have certain clinical significance in AAV, which is a new exploration of the clinical value of ANA.

Immunoglobulin M: A Neglected Serum Biomarker in Treatment-Naive Primary Biliary Cholangitis With Normal Alkaline Phosphatase

The diagnosis of primary biliary cholangitis (PBC) in patients with seropositive anti-mitochondrial antibody (AMA) but normal alkaline phosphatase (ALP) depends on a liver biopsy. We aimed to reveal potential serum biomarkers that could suggest the necessity of a liver biopsy in such patients. Retrospective analysis was performed. Subjects who were treatment naive with seropositive AMA but normal ALP and who underwent at least one liver biopsy between 2008 and 2020 were included in this study. Histologic biopsies were evaluated by two experienced pathologists blinded to the serum tests. A total of 115 patients who were treatment naive were included in this study. Of these, 77 patients (67%) exhibited histologic PBC features and nonspecific histologic features were found in the remaining 38 (33%) patients. Multivariate analysis suggested that baseline serum immunoglobulin M (IgM) >0.773 × upper limit of normal (ULN) (P < 0.001) and age >42 years (P = 0.002) were associated with the diagnosis of PBC through liver biopsies. A significant decrease in the median levels of gamma-glutamyl transpeptidase (GGT) and IgM was found in 54 patients with PBC who received ursodeoxycholic acid (UDCA). Conclusion: For patients who were treatment naive with seropositive AMA but normal ALP, baseline serum IgM >0.773 × ULN and age >42 years were the factors that strongly suggested a diagnosis of PBC. In these patients receiving UDCA, a dynamic monitoring of GGT and IgM might be helpful in evaluating therapeutic responses.

Rational development and application of biomarkers in the field of autoimmunity: A conceptual framework guiding clinicians and researchers

Clear guidance is needed in the development and implementation of laboratory biomarkers in medicine. So far, no standardized phased approach is established that would pilot researchers and clinicians in this process. This leads to often incompletely validated biomarkers, which can bear the consequence of wrong applications, misinterpretation and inadequate management in the clinical context.

In this conceptual article, we describe a stepwise approach to develop and comprehensively validate laboratory biomarkers. We will delineate basic steps including technical performance, pre-analytical issues, and biological variation, as well as advanced aspects of biomarker utility comprising interpretability, diagnostic and prognostic accuracy, and health-care outcomes. These aspects will be illustrated by using well-known examples from the field of immunology.

The application of this conceptual framework will guide researchers in conducting meaningful projects to develop and evaluate biomarkers for the use in clinical practice. Furthermore, clinicians will be able to adequately interpret pre-clinical and clinical diagnostic literature and rationally apply biomarkers in clinical practice. Improvement in the implementation and application of biomarkers might relevantly change the management and outcomes of our patients for the better.

Recent advances in clinical practice: epidemiology of autoimmune liver diseases

Autoimmune liver diseases are chronic inflammatory hepatobiliary disorders that when classically defined encompass three distinctive clinical presentations; primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Meaningful changes in disease epidemiology are reported, with increasing incidence and prevalence of AIH and PSC in Europe, and rising prevalence of PBC across Europe, North America and the Asia-Pacific region. However, there appears to be very significant global variation with contemporary incidence rates of disease per 100 000 ranging from 0.84 to 2.75 for PBC, 0.1 to 4.39 for PSC and 0.4 to 2.39 for AIH. Prevalence corresponds, and per 100 000 estimates for PBC range from 1.91 to 40.2, for PSC between 0.78 and 31.7 and for AIH from 4.8 to 42.9. Population-based studies and multicentre observational cohort series provide improved understanding of the clinical course that patients experience, highlighting variations in presenting phenotypes geographically and temporally. Collectively, while autoimmune liver diseases are rare, the clinical burden is disproportionately high relative to population incidence and prevalence. Age, sex and race also impact clinical outcomes, and patient morbidity and mortality are reflected by high need for gastroenterology, hepatology and organ transplant services.

Clinical Management of Primary Biliary Cholangitis-Strategies and Evolving Trends

PBC is a chronic progressive autoimmune disorder involving the destruction of intrahepatic small bile ducts, cholestasis, fibrosis, and ultimately cirrhosis if left untreated. It is largely driven by the autoimmune response, but bile acids and the intestinal microbiota are implicated in disease progression as well. The only drugs licensed for PBC are UDCA and OCA. UDCA as a first-line and OCA as a second-line therapy are safe and effective, but the lack of response in a significant portion of patients and inadequate control of symptoms such as fatigue and pruritus remain as concerns. Liver transplantation is an end-stage therapy for many patients refractory to UDCA, which gives excellent survival rates but also moderate to high recurrence rates. The limited options for FDA-approved PBC therapies necessitate the development of alternative approaches. Currently, a wide variety of experimental drugs exist targeting immunological and physiological aspects of PBC to suppress inflammation. Immunological therapies include drugs targeting immune molecules in the B cell and T cell response, and specific cytokines and chemokines implicated in inflammation. Drugs targeting bile acids are also noteworthy as bile acids can perpetuate hepatic inflammation and lead to fibrosis over time. These include FXR agonists, ASBT inhibitors, and PPAR agonists such as bezafibrate and fenofibrate. Nonetheless, many of these drugs can only delay disease progression and fail to enhance patients' quality of life. Nanomedicine shows great potential for treatment of autoimmune diseases, as it provides a new approach that focuses on tolerance induction rather than immunosuppression. Tolerogenic nanoparticles carrying immune-modifying agents can be engineered to safely and effectively target the antigen-specific immune response in autoimmune diseases. These may work well with PBC especially, given the anatomical features and immunological specificity of the disease. Nanobiological therapy is thus an area of highly promising research for future treatment of PBC.

Ursodeoxycholic acid impairs liver-infiltrating T-cell chemotaxis through IFN-γ and CX3CL1 production in primary biliary cholangitis

Ursodeoxycholic acid (UDCA) is the primary treatment for primary biliary cholangitis (PBC), but its mechanism of action remains unclear. Studies suggest that UDCA enhances NF erythroid 2-related factor 2 (NFE2L2) expression and that the interaction between IFN-γ and C-X3-C motif chemokine ligand 1 (CX3CL1) facilitates biliary inflammation in PBC. Therefore, we examined the effects of UDCA on the expression of IFN-γ and CX3CL1 in in vitro and in vivo PBC models such as human liver tissue, a murine model, cell lines, and isolated human intrahepatic biliary epithelial cells (IHBECs). We observed a significant decrease in IFN-γ mRNA levels and positive correlations between IFN-γ and CX3CL1 mRNA levels post-UDCA treatment in PBC livers. NFE2L2-mediated transcriptional activation was significantly enhanced in UDCA-treated Jurkat cells. In 2-octynoic acid-immunized mice, IFN-γ production by liver-infiltrating T cells was dependent on NFE2L2 activation. IFN-γ significantly and dose-dependentlyinduced CX3CL1 expression, which was significantly decreased in HuCC-T1 cells and IHBECs upon UDCA treatment. These results suggest that UDCA-induced suppression of IFN-γ and CX3CL1 production attenuates the chemotactic and adhesive abilities of liver-infiltrating T cells in PBC.

Autoimmune liver disease-associated serologic profiling in Chinese patients with acute hepatitis E virus infection

The association between hepatitis E virus (HEV) and autoimmune liver diseases has been well-researched; however, the focus has been on autoimmune hepatitis (AIH) and not primary biliary cholangitis (PBC). Therefore, we aimed to investigate the prevalence and evolution of AIH- and PBC-related autoantibodies in Chinese patients with HEV infection. In this retrospective study, 164 patients with acute HEV were included, specifically those whose liver autoantibody results were available and who had no pre-existing liver disease at the time of HEV diagnosis. Positive liver autoimmune serology was present in 69 (42.1%) patients and 21 (12.8%) had at least two autoantibodies at diagnosis. Greater age and alkaline phosphatase levels were independent risk factors for autoantibody positivity. Follow-up serologic tests, which were available for 27 of the 69 autoantibody-positive patients, showed that although antinuclear antibodies disappeared in 11/20 (55.0%) and antimitochondrial antibodies disappeared in 4/5 (80%) patients, 16 still remained positive for autoantibodies and two of them even developed new PBC-related antibodies, as described below. One patient developed a rim-like ANA pattern, accompanied by an enhancement of anti-gp210 positivity; and the other was diagnosed as PBC, based on chronic elevation of cholestatic enzymes and presentation with de novo AMA-M2, 18 months after HEV clearance. In conclusion, AIH- and PBC-related autoantibodies are frequently present during acute HEV infection, indicating that HEV should be excluded before diagnosing AIH and/or PBC. Importantly, some cases maintained or developed autoantibodies after viral clearance, and one patient subsequently developed PBC, highlighting that these individuals warrant long-term follow-up.

Current understanding of primary biliary cholangitis

Primary biliary cholangitis (PBC) causes chronic and persistent cholestasis in the liver, eventually resulting in cirrhosis and hepatic failure without appropriate treatment. PBC mainly develops in middle-aged women, but it is also common in young women and men. PBC is considered a model of autoimmune disease because of the presence of disease-specific autoantibodies, that is, antimitochondrial antibodies (AMAs), intense infiltration of mononuclear cells into the bile ducts, and a high prevalence of autoimmune diseases such as comorbidities. Histologically, PBC is characterized by degeneration and necrosis of intrahepatic biliary epithelial cells surrounded by a dense infiltration of mononuclear cells, coined as chronic non-suppurative destructive cholangitis, which leads to destructive changes and the disappearance of small- or medium-sized bile ducts. Since 1990, early diagnosis with the detection of AMAs and introduction of ursodeoxycholic acid as first-line treatment has greatly altered the clinical course of PBC, and liver transplantation-free survival of patients with PBC is now comparable to that of the general population.

Primary biliary cholangitis with normal alkaline phosphatase: A neglected clinical entity challenging current guidelines

BACKGROUND & AIM

The diagnosis of primary biliary cholangitis (PBC), an uncommon immune-mediated cholestatic liver disease, is based on positive circulating anti-mitochondrial (AMA) and/or PBC-specific anti-nuclear autoantibodies (ANA), coupled with elevated serum alkaline phopsphatase (ALP) levels. Timely initiation of treatment with ursodeoxycholic acid prevents progression to cirrhosis and liver failure. We aimed at investigating liver histology in patients with normal ALP level and positive AMA and/or PBC-specific ANA.

METHODS

We searched the Swiss PBC Cohort Study database, which includes subjects with positive PBC autoimmune serology and normal ALP levels, for patients who underwent a liver biopsy. Histological slides were centrally reviewed by an expert liver pathologist, and sera were centrally re-tested for AMA and ANA.

RESULTS

30 patients were included; 90% females, median age 53 (range 27-72) years. Twenty-four (80%) had liver histology typical for (n = 2), consistent with (n = 16) or suggestive of (n = 6) PBC, including three of four AMA-negative ANA-positive patients. Among 22 ursodeoxycholic acid treated patients, 14 had elevated GGT levels before treatment; a significant decrease of the median GGT level between pre- (1.46 x ULN) and post- (0.43 x ULN) treatment (p = 0.0018) was observed.

CONCLUSIONS

In our series, a high proportion of AMA positive patients with normal ALP levels have PBC. For the first time we show histological diagnosis of PBC in AMA-negative/PBC-specific ANA-positive subjects and the potential role of GGT as a biomarker in PBC patients with normal baseline ALP levels. Current guidelines for the diagnosis of PBC do not cover the whole extent of PBC presentation, with important clinical implications in terms of timely treatment initiation.

Primary biliary cholangitis management: controversies, perspectives and daily practice implications from an expert panel

Primary biliary cholangitis (PBC) is a rare progressive immune-mediated liver disease that, if not adequately treated, may culminate in end-stage disease and need for transplantation. According to current guidelines, PBC is diagnosed in the presence of antimitochondrial antibodies (AMA) or specific antinuclear antibodies, and of a cholestatic biochemical profile, while biopsy is recommended only in selected cases. All patients receive ursodeoxycholic acid (UDCA) in first line; the only registered second-line therapy is obeticholic acid (OCA) for UDCA-inadequate responders. Despite the recent advances in understanding PBC pathogenesis and developing new treatments, many grey areas remain. Six Italian experts selected the following topics as the most urgent to address in PBC management: diagnosis and natural history of PBC: as a portion of the subjects with isolated AMA, normal alkaline phosphatase (ALP) levels and no symptoms of liver disease could have PBC by histology, defining how to manage and follow this population is crucial; role of liver biopsy: recent evidence suggests that biopsy may provide relevant information for risk stratification and prediction of UDCA response, possibly facilitating personalized approaches; risk stratification: the tools for risk stratification are well established, but some issues (eg bile acid dosage in routine practice) remain controversial; and therapy: those in more advanced stages of development are nuclear receptor modulators and fibrates, but more data are needed to plan personalized strategies. In this manuscript, for each topic, current evidence, controversies and future perspectives are summarized with the possible implications for clinical practice.

Immune system and cholangiocytes: A puzzling affair in primary biliary cholangitis

Primary biliary cholangitis (PBC) is a cholestatic liver disease characterized by the destruction of the small and medium bile ducts. Its pathogenesis is still unknown. Despite the genome wide association study findings, the therapies targeting the cytokines pathway, tested so far, have failed. The concept of the biliary epithelium as a key player of the PBC pathogenesis has emerged over the last few years. It is now well accepted that the biliary epithelial cells (BECs) actively participate to the genesis of the damage. The chronic stimulation of BECs via microbes and bile changes the cell phenotype toward an active state, which, across the production of proinflammatory mediators, can recruit, retain, and activate immune cells. The consequent immune system activation can in turn damage BECs. Thus, the crosstalk between both innate and adaptive immune cells and the biliary epithelium creates a paracrine loop responsible for the disease progression. In this review, we summarize the evidence provided in literature about the role of BECs and the immune system in the pathogenesis of PBC. We also dissect the relationship between the immune system and the BECs, focusing on the unanswered questions and the future potential directions of the translational research and the cellular therapy in this area.

A patient with primary biliary cholangitis, autoimmune hepatitis, and primary sclerosing cholangitis variant syndrome

Overlap between autoimmune hepatitis (AIH) and either primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC) is not rare and has extensively been reported. We herein report the first well documented case of triple overlap. A 68-year-old male patient presented with asymptomatic PBC including normal alkaline phosphatase serum level, developed AIH five years later, associated with magnetic resonance cholangiopancreatography biliary changes typical for PSC. Despite treatment with ursodeoxycholic acid and mycophenolate mofetil, owing to prednisone and azathioprine intolerance, he continued to have interface hepatitis and developed increasing fibrosis at follow-up liver biopsy. Our case report raises awareness for this rare and difficult to diagnose and treat clinical phenotype.

Recurrence of disease following organ transplantation in autoimmune liver disease and systemic lupus erythematosus

Disease recurrence after organ transplantation associated with graft failure is a major clinical challenge in autoimmune diseases. Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune Hepatitis (AIH) are the three most common (autoimmune liver diseases) ALD for which liver transplantation (LT) is the most effective treatment option for patients with end-stage diseases. Although the 5- and 10-year survival rates of post-LT patients are remarkable (80-84% and 71-79% in PBC, 73-87% and 58-83% in PSC, 76-79% and 67-77% respectively in AIH patients), post-LT disease recurrence is not uncommon. Here, we summarize literature findings on disease recurrence of these ALD with emphasis on the incidence, risk factors and impact on long-term outcome. We noted that the incidence of disease recurrence varies between studies, which ranges from 53% to 10.9% in PBC, 8.2% to 44.7% in PSC and 7% to 42% in AIH. The variations are likely due to differences in study design, such as sample size, duration of studies and follow up time. This is further compounded by the lack of precise clinical diagnosis criteria and biomarkers of disease recurrence in these ALD, variation in post-LT treatment protocols to prevent disease recurrence and a multitude of risk factors associated with these ALD. While recurrence of PBC and AIH does not significantly impact long term outcome including overall survival, recurrent PSC patients often require another LT. Renal transplantation, like LT, is the treatment of choice in patients with end-stage lupus nephritis. While calcineurin inhibitor (CNI) and immunosuppressive drugs have improved the survival rate, post-transplant recurrence of lupus nephritis from surveillance-biopsy proven lupus nephritis range from 30% to 44%. On the other hand, recurrence of post-transplant lupus nephritis from registry survey analysis were only 1.1% to 2.4%. In general, risk factors associated with an increased frequency of post-transplant recurrence of autoimmune diseases are not clearly defined. Large scale multi-center studies are needed to further define guidelines for the diagnosis and clinical management to minimize disease recurrence and improve outcomes of post-transplant patients.

The challenges of primary biliary cholangitis: What is new and what needs to be done

Primary Biliary Cholangitis (PBC) is an uncommon, chronic, cholangiopathy of autoimmune origin and unknown etiology characterized by positive anti-mitochondrial autoantibodies (AMA), female preponderance and progression to cirrhosis if left untreated. The diagnosis is based on AMA- or PBC-specific anti-nuclear antibody (ANA)-positivity in the presence of a cholestatic biochemical profile, histologic confirmation being mandatory only in seronegative cases. First-line treatment is ursodeoxycholic acid (UDCA), which is effective in preventing disease progression in about two thirds of the patients. The only approved second-line treatment is obeticholic acid. This article summarizes the most relevant conclusions of a meeting held in Lugano, Switzerland, from September 23rd-25th 2018, gathering basic and clinical scientists with various background from around the world to discuss the latest advances in PBC research. The meeting was dedicated to Ian Mackay, pioneer in the field of autoimmune liver diseases. The role of liver histology needs to be reconsidered: liver pathology consistent with PBC in AMA-positive individuals without biochemical cholestasis is increasingly reported, raising the question as to whether biochemical cholestasis is a reliable disease marker for both clinical practice and trials. The urgent need for new biomarkers, including more accurate markers of cholestasis, was also widely discussed during the meeting. Moreover, new insights in interactions of bile acids with biliary epithelia in PBC provide solid evidence of a role for impaired epithelial protection against potentially toxic hydrophobic bile acids, raising the fundamental question as to whether this bile acid-induced epithelial damage is the cause or the consequence of the autoimmune attack to the biliary epithelium. Strategies are needed to identify difficult-to-treat patients at an early disease stage, when new therapeutic approaches targeting immunologic pathways, in addition to bile acid-based therapies, may be effective. In conclusion, using interdisciplinary approaches, groundbreaking advances can be expected before long in respect to our understanding of the etiopathogenesis of PBC, with the ultimate aim of improving its treatment.