Large-scale characterization study of patients with antimitochondrial antibodies but nonestablished primary biliary cholangitis

Immunopathogenesis of Primary Biliary Cholangitis, Primary Sclerosing Cholangitis and Autoimmune Hepatitis: Themes and Concepts

Autoimmune liver diseases include primary biliary cholangitis, primary sclerosing cholangitis, and autoimmune hepatitis, a family of chronic immune-mediated disorders that target hepatocytes and cholangiocytes. Treatments remain nonspecific, variably effective, and noncurative, and the need for liver transplantation is disproportionate to their rarity. Development of effective therapies requires better knowledge of pathogenic mechanisms, including the roles of genetic risk, and how the environment and gut dysbiosis cause immune cell dysfunction and aberrant bile acid signaling. This review summarizes key etiologic and pathogenic concepts and themes relevant for clinical practice and how such learning can guide the development of new therapies for people living with autoimmune liver diseases.

Rare liver diseases in Egypt: Clinical and epidemiological characterization

Illnesses that afflict a tiny number of individuals are referred to as rare diseases (RDs), sometimes called orphan diseases. The local healthcare systems are constantly under financial, psychological, and medical strain due to low incidence rates, unusual presentations, flawed diagnostic standards, and a lack of treatment alternatives for these RDs. The effective management of the once widely spread viral hepatitis B and C has altered the spectrum of liver diseases in Egypt during the last several years. The detection of uncommon disorders such as autoimmune, cholestatic, and hereditary liver diseases has also been made easier by the increasing knowledge and greater accessibility of specific laboratory testing. Finally, despite Egypt's large population, there are more uncommon liver disorders than previously thought. This review article discusses the clinical and epidemiological characteristics of a few uncommon liver disorders and the information currently accessible concerning these illnesses in Egypt.

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.

Associations between anti-mitochondrial antibodies and cardiac involvement in idiopathic inflammatory myopathy patients : A systematic review and meta-analysis

OBJECTIVE

The objectives of this study are to analyze the association between anti-mitochondrial antibody (AMA) and cardiac involvement in idiopathic inflammatory myopathy (IIM) and to evaluate the diagnostic value of AMA for cardiac involvement in IIM patients.

METHODS

We conducted a comprehensive search in PubMed, Web of Science, EMBASE, and the Cochrane Library to identify English-language studies published before November 19, 2021. Stata 12.0 software (Stata Corp., College Station, TX, USA) was used for the statistical analyses. We used the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and summary receiver operating characteristic (SROC) curve to evaluate the diagnostic value of AMA for cardiac involvement in IIM patients. Statistical heterogeneity of studies was assessed using the I2 statistic with 95% confidence intervals (95% CIs).

RESULTS

Seven studies were included in the final analyses, with a total of 2308 IIM patients (including 171 AMA-positive and 2137 AMA-negative patients). The pooled sensitivity of AMA for cardiac involvement in IIM patients was 0.29 (95% CI: 0.19-0.43) and specificity was 0.92 (95% CI: 0.88-0.96). The pooled PLR was 3.9 (95% CI: 2.82-5.38), NLR was 0.76 (95% CI: 0.66-0.88), and the diagnostic odds ratio (DOR) was 5 (95% CI: 3-7). The area under the SROC curve was 0.76 (95% CI: 0.72-0.79).

CONCLUSION

The overall diagnostic value of AMA may not be very high for cardiac involvement in IIM patients.

Primary Biliary Cholangitis: Epidemiology, Diagnosis, and Presentation

Using ursodeoxycholic acid as a standard treatment and for its ability to test for antimitochondrial antibody to accelerate diagnosis, survival of primary biliary cholangitis patients has approached that of the general population, leading to a change in nomenclature from primary biliary cirrhosis to primary biliary cholangitis to more accurately describe the disease.

Autoimmune Markers in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The most common antibody associated with PBC is the anti-mitochondrial antibody (AMA), present in 90% to 95% of patients. For patients who are AMA-negative, novel biomarkers, such as antinuclear antibody-specific antibodies Sp100 and gp210 and anti-kelch-like-12 and anti-hexokinase-1 antibodies, may further aid in the diagnosis of PBC. Several laboratory methods, including immunofluorescence, enzyme-linked immunosorbent assay, immunoblotting, and bead-based assays, exist to evaluate for the presence of antibodies. This article describes various methods used to evaluate antibodies as well as describe the antibodies present in PBC.

High neutrophil-lymphocyte ratio indicates a worse response to ursodeoxycholic acid in primary biliary cholangitis: a retrospective cohort study

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease characterized by inflammation of the interlobular bile ducts. Ursodeoxycholic acid (UDCA) is the only FDA approved first-line therapy for PBC, but up to 40% of patients with PBC have an incomplete response to UDCA. Neutrophil-to-lymphocyte (NLR) has been used to predict prognosis in various liver diseases. There is limited evidence on the treatment response to UDCA in PBC patients. Our study aimed to evaluate the relationship between NRL and the response to UDCA treatment in PBC patients.

METHODS

A total of 257 primary biliary cholangitis (PBC) patients treated with UDCA (13-15 mg/kg/d) were enrolled in this retrospective study. The response to treatment was evaluated based on alkaline phosphatase levels ≤1.67 times the upper limit of the normal value after 12 months of UDCA treatment. Multivariable logistic regression analysis was performed to investigate the association between NLR at baseline and the response to 12 months of UDCA treatment after adjusting for important confounding variables. The stability of the results was evaluated by unadjusted and adjusted models.

RESULTS

The results of multiple regression analysis showed that NLR at baseline was positively associated with the nonresponse to UDCA treatment after adjustments for potential confounders (age, sex, BMI, hypertension, arterial plaque, thyroid disease, jaundice, albumin, globulin, total bile acid, ALP, GGT, LDLC, total cholesterol, hemoglobin, and APTT) (OR = 1.370, 95% CI 1.066-1.761). These results reveal that NLR is an independent risk factor for UDCA treatment nonresponse.

CONCLUSIONS

Our results suggest that PBC patients with a high NLR had a worse response to UDCA therapy.

A population-based characterization study of anti-mitochondrial M2 antibodies and its consistency with anti-mitochondrial antibodies

OBJECTIVE

This study aims to estimate the prevalence of anti-mitochondrial antibody subtype M2 (AMA-M2) and assess its consistency with AMA in a general population.

METHODS

A total of 8954 volunteers were included to screen AMA-M2 using enzyme-linked immunosorbent assay. Sera with AMA-M2 >50 RU/mL were further tested for AMA using an indirect immunofluorescence assay.

RESULTS

The population frequency of AMA-M2 positivity was 9.67%, of which 48.04% were males and 51.96% were females. The AMA-M2 positivity in males had a peak and valley value of 7.81% and 16.88% in those aged 40 to 49 and ≥70 years, respectively, whereas it showed a balanced age distribution in females. Transferrin and immunoglobulin M were the risk factors for AMA-M2 positivity and exercise was the only protective factor. Of 155 cases with AMA-M2 >50 RU/mL, 25 cases were AMA-positive, with a female-to-male ratio of 5.25:1. Only 2 people, with very high AMA-M2 of 760 and >800 RU/mL, met the diagnostic criteria of primary biliary cholangitis (PBC), making the prevalence of PBC 223.36 per million in southern China.

CONCLUSION

We found that AMA-M2 has a low coincidence rate with AMA in the general population. A new decision-making point for AMA-M2 is needed to improve consistency with AMA and diagnostic accuracy.

Antimitochondrial antibody associated with liver cirrhosis in patients with primary biliary cholangitis

Antimitochondrial antibody (AMA) serves as a serological marker for diagnosing primary biliary cholangitis (PBC). However, the association between AMA and prognosis for PBC patients remains unclear. The objective of this study was to investigate the relationship between AMA and cirrhosis in PBC patients. This retrospective study enrolled 225 PBC patients, including 127 with liver cirrhosis and 98 without cirrhosis. AMA was tested by indirect immunofluorescence (IIF) with rat kidney as the substrate. AMA-M2 and M2-3E were detected by line immunoassay (LIA). The overall positivity rate for AMA detection in PBC patients was 80.9%. The positivity rates of IIF-AMA, AMA-M2, and M2-3E were significantly higher in patients with liver cirrhosis than in those without cirrhosis (73.2% vs. 52.0%, 74.0% vs. 51.0%, and 80.3% vs. 60.2%, respectively). In multivariate logistic regression, IIF-AMA (OR: 3.05, 95% CI: 1.59-5.87), AMA-M2 (OR: 3.11, 95% CI: 1.61-6.01), and M2-3E (OR: 3.29, 95% CI: 1.63-6.66) remained significantly associated with an increased incidence of liver cirrhosis. Moreover, in multinomial logistic regression, IIF-AMA (compensated cirrhosis, OR: 3.55, 95% CI: 1.49-8.44; decompensated cirrhosis, OR: 2.86, 95% CI: 1.32-6.18), AMA-M2 (compensated cirrhosis, OR: 4.74, 95% CI: 1.94-11.58; decompensated cirrhosis, OR: 2.51, 95% CI: 1.19-5.33), and M2-3E (compensated cirrhosis, OR: 4.92, 95% CI: 1.74-13.96; decompensated cirrhosis, OR: 2.91, 95% CI: 1.28-6.64) were all found to be associated with different stages of liver cirrhosis. AMA was found to be associated with the occurrence of liver cirrhosis in PBC patients. Additionally, AMA was also related to different stages of liver cirrhosis, including compensated and decompensated cirrhosis.

Sequence of events leading to primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that is observed more frequently in middle-aged women. This disorder is considered an autoimmune disease, since liver injury is sustained by the presence of self-directed antimitochondrial antibodies targeting the bile duct cells. The prognosis may vary depending on an early diagnosis and response to therapy. However, nearly a third of patients can progress to liver cirrhosis, thus requiring a liver transplant. Traditional immunosuppressive therapies, commonly employed for other autoimmune diseases, have limited effects on PBC. In fact, dramatic functional changes that occur in the biliary epithelium in the course of inflammation play a major role in perpetuating the injury. In this minireview, after a background on the disease and possible predisposing factors, the sequential cooperation of cellular/molecular events leading to end-stage PBC is discussed in detail. The rise and maintenance of the autoimmune process, as well as the response of the biliary epithelia during inflammatory injury, are key factors in the progression of the disease. The so-called "ductular reaction (DR)", intended as a reactive expansion of cells with biliary phenotype, is a process frequently observed in PBC and partially understood. However, recent findings suggest a strict relationship between this pathological picture and the progression to liver fibrosis, cell senescence, and loss of biliary ducts. All these issues (onset of chronic inflammation, changes in secretive and proliferative biliary functions, DR, and its relationship with other pathological events) are discussed in this manuscript in an attempt to provide a snapshot, for clinicians and researchers, of the most relevant and sequential contributors to the progression of this human cholestatic disease. We believe that interpreting this disorder as a multistep process may help identify possible therapeutic targets to prevent evolution to severe disease.

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.

Risk Stratification in Primary Biliary Cholangitis

Primary Biliary Cholangitis (PBC) is a chronic cholestatic liver disease with a heterogeneous presentation, symptomatology, disease progression, and response to therapy. The current risk stratification assessment, aimed at identifying patients with a higher risk of disease progression, encompasses an in-depth analysis of demographic data, clinical and laboratory findings, antibody profiles, and the evaluation of liver fibrosis using both invasive and noninvasive techniques. Treatment response scores after one year of therapy remain to date a major factor influencing the prognosis of PBC patients. While the initial therapeutic approach with ursodeoxycholic acid (UDCA) is universally applied, new second-line treatment options have recently emerged, with many others under investigation. Consequently, the prevailing one-size-fits-all approach is poised to be supplanted by tailored strategies, ensuring high-risk patients receive the most appropriate treatment regimen from diagnosis. This will require the development of a risk prediction model to assess, at the time of diagnosis, the course, outcome, and response to first and additional treatments of PBC patients. This manuscript provides a comprehensive overview of the current and emerging tools used for risk stratification in PBC and speculates on how these developments might shape the disease landscape in the near future.

Excellent outcome in patients with primary biliary cholangitis in Northwest Italy followed up for up to 30 years

OBJECTIVE

Primary biliary cholangitis (PBC) is a rare chronic autoimmune cholangiopathy, characterized by a variable course and response to treatment. We aimed to describe long-term outcomes of PBC patients referred to three academic centres in Northwest Italy.

METHODS

This is an ambispective cohort study of PBC patients (retrospective component: diagnosis before 1 January 2019; prospective component: thereafter), including 302 patients: 101 (33%) followed up in Novara, 86 (28%) in Turin, 115 (38%) in Genoa. Clinical features at diagnosis, biochemical response to therapy and survival were analyzed.

RESULTS

Among the 302 patients (88% women, median age 55 years, median follow-up 75 months), alkaline phosphatase (ALP) levels significantly decreased during treatment with ursodeoxycholic acid (UDCA, P < 0.0001) and obeticholic acid (P < 0.0001). At multivariate analysis, ALP at diagnosis was predictive of 1-year biochemical response to UDCA [odds ratio 3.57, 95% confidence interval (CI) 1.4-9, P < 0.001]. Estimated median survival free of liver transplantation and hepatic complications was 30 years (95% CI 19-41). Bilirubin level at diagnosis was the only independent risk factor for the combined outcome of death, transplantation or hepatic decompensation (hazard ratio, 1.65, 95% CI 1.66-2.56, P = 0.02). Patients presenting with total bilirubin at diagnosis ≥0.6 times the upper normal limit (ULN) had a significantly lower 10-year survival compared to those with bilirubin <0.6 times ULN (63% vs. 97%, P < 0.0001).

CONCLUSION

In PBC, both short-term response to UDCA and long-term survival can be predicted by simple conventional biomarkers of disease severity, obtained at diagnosis.

New Treatment Paradigms in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an archetypal autoimmune disease. Chronic lymphocytic cholangitis is associated with interface hepatitis, ductopenia, cholestasis, and progressive biliary fibrosis. People living with PBC are frequently symptomatic, experiencing a quality-of-life burden dominated by fatigue, itch, abdominal pain, and sicca complex. Although the female predominance, specific serum autoantibodies, immune-mediated cellular injury, as well as genetic (HLA and non-HLA) risk factors, identify PBC as autoimmune, to date treatment has focused on cholestatic consequences. Biliary epithelial homeostasis is abnormal and contributes to disease. The impact of cholangiocyte senescence, apoptosis, and impaired bicarbonate secretion enhances chronic inflammation and bile acid retention. First-line therapy is a non-specific anti-cholestatic agent, ursodeoxycholic acid. For those with residual cholestasis biochemically, obeticholic acid is introduced, and this semisynthetic farnesoid X receptor agonist adds choleretic, anti-fibrotic, and anti-inflammatory activity. Future PBC licensed therapy will likely include peroxisome proliferator activated receptor (PPAR) pathway agonists, including specific PPAR-delta agonism (seladelpar), as well as elafibrinor and saroglitazar (both with broader PPAR agonism). These agents dovetail the clinical and trial experience for off-label bezafibrate and fenofibrate use. Symptom management is essential, and encouragingly, PPAR agonists reduce itch; IBAT inhibition (eg, linerixibat) also appears promising for pruritus. For those where liver fibrosis is the target, NOX inhibition is being evaluated. Earlier stage therapies in development include therapy to impact immunoregulation in patients, as well other approaches to treating pruritus (eg, antagonists of MrgprX4). Collectively the PBC therapeutic landscape is exciting. Therapy goals are increasingly proactive and individualized and aspire to rapidly achieve normal serum tests and quality of life with prevention of end-stage liver disease.

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.

Primary biliary cholangitis: Epidemiology, prognosis, and treatment

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease characterized by a destructive, small duct, and lymphocytic cholangitis, and marked by the presence of antimitochondrial antibodies. The incidence and prevalence of PBC vary widely in different regions and time periods, and although disproportionally more common among White non-Hispanic females, contemporary data show a higher prevalence in males and racial minorities than previously described. Outcomes largely depend on early recognition of the disease and prompt institution of treatment, which, in turn, are directly influenced by provider bias and socioeconomic factors. Ursodeoxycholic acid remains the initial treatment of choice for PBC, with obeticholic acid and fibrates (off-label therapy) reserved as add-on therapy for the management of inadequate responders or those with ursodeoxycholic acid intolerance. Novel and repurposed drugs are currently at different stages of clinical development not only for the treatment of PBC but also for its symptomatic management. Here, we summarize the most up-to-date data regarding the epidemiology, prognosis, and treatment of PBC, providing clinically useful information for its holistic management.

Detection of M2-Type Anti-Mitochondrial Autoantibodies against Specific Subunits in the Diagnosis of Primary Biliary Cholangitis in Patients with Discordant Results

BACKGROUND

M2-type anti-mitochondrial autoantibodies are considered the hallmark of primary biliary cholangitis and are directed mainly against the E2 subunits of the 2-oxo acid dehydrogenase complex enzymes (PDC, BCOADC and OGDC). The aim of this study was to determine whether a Dot-blot that includes these E2 subunits separately could confirm the results of methods with non-separated subunits in patients with low positive or discordant results between techniques.

METHODS

Sera of 24 patients with low positive or discordant results and of 10 patients with clear positive results by non-separated subunits methods were analyzed by Dot-blot with separated subunits.

RESULTS

Autoantibodies against E2 subunits of PDC, BCOADC or OGDC were detected in all patients, except in one case from the low positive or discordant results group, by Dot-blot with separated subunits.

CONCLUSIONS

It would be advisable to use methods that include the three E2 subunits, and a Dot-blot with separated subunits could confirm doubtful cases by non-separated assays.

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.

Global burden of Liver Disease: 2023 Update

Liver disease accounts for 2 million deaths and is responsible for 4% of all deaths (1 out of every 25 deaths worldwide); approximately 2/3 of all liver related deaths occur in men. Deaths are largely attributable to complications of cirrhosis and hepatocellular carcinoma, with acute hepatitis accounting for a smaller proportion of deaths. The most common causes of cirrhosis worldwide are related to viral hepatitis, alcohol, and nonalcoholic fatty liver disease (NAFLD). Hepatotropic viruses are the etiological factor in most cases of acute hepatitis, but drug-induced liver injury increasingly accounts for a significant proportion of cases. This iteration of the global burden of liver disease is an update of the 2019 version and focuses mainly on areas where significant new information is available like alcohol-associated liver disease, NAFLD, viral hepatitis, and HCC. We also devote a separate section to the burden of liver disease in Africa, an area of the world typically neglected in such documents.

Inflammatory Myopathy Associated with Anti-mitochondrial Antibody-negative Primary Biliary Cholangitis Diagnosed by a Liver Biopsy

Anti-mitochondrial antibody (AMA)-associated myopathies represent a homogeneous disease entity with severe arrhythmia and slowly progressive proximal muscle weakness with lordotic posture, irrespective of the presence of primary biliary cholangitis (PBC). We herein report a case of myositis associated with PBC without AMAs. A 48-year-old woman presented with clinical features very similar to AMA-associated myositis, despite negative AMAs. PBC, ascertained by a liver biopsy performed based on mildly elevated liver enzymes, and the efficacy of steroid therapy on muscle weakness confirmed the diagnosis of immune-mediated myositis. When AMAs are negative, a liver biopsy is indispensable for diagnosing treatable PBC-associated myositis.

Presence of anti-gp210 or anti-sp100 antibodies in AMA-positive patients may help support a diagnosis of primary biliary cholangitis

BACKGROUND

Anti-mitochondrial antibody (AMA) positivity is not always associated with primary biliary cholangitis (PBC). We aimed to determine the additional value of anti-sp100 or anti-gp210 antibody in AMA-positive patients for PBC.

METHODS

Patients (n = 190) and healthy donors (n = 50) were evaluated for AMA, anti-gp210 and anti-sp100 antibodies by ELISA. Antibody frequencies in cohorts and performance characteristics in some patients categorized as 'definitive-', 'probable-', and 'no PBC' were determined following review of their charts.

RESULTS

Of the patients (n = 190), 38.4% were AMA-positive (n = 73) and 61.6% AMA-negative (n = 117). Frequency of anti-sp100 or anti-gp210 antibody was 17.8%, 2.6%, and 0% in AMA-positive, AMA-negative and healthy controls, respectively. Clinical data was available for 63 of 73 AMA-positive patients with 28.6%, 22.2%, and 49.2% categorized as definite, probable, and no PBC, respectively. Patients with definite PBC had higher mean levels of AMA and frequencies of sp100 or gp210 antibody compared to other groups. Sensitivities were low (anti-sp100: 18.8% and anti-gp210: 16.7%) with specificities above 98.0% for both.

CONCLUSION

AMA-positive patients positive for anti-sp100 or anti-gp210 antibody were more likely to have a diagnosis of definite or probable PBC than those with AMA alone. Use of all tests is likely to improve characterization of patients at-risk for PBC.

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.

Autoantibodies in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic immune-mediated liver disease characterized by a lymphocytic cholangitis, with subsequent cholestasis, progressive liver fibrosis, and ultimately complications arising from end-stage liver disease. Testing for autoantibodies is important in the diagnosis of PBC, as well as stratifying prognosis. This review focuses on the role of autoantibodies in the diagnosis of PBC, as well as the relationship between autoantibodies with pathophysiology and prognostication, along with a discussion regarding novel and other related disease autoantibodies.

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.

Autoantibodies Associated with Autoimmune Liver Diseases in a Healthy Population: Evaluation of a Commercial Immunoblot Test

Autoantibodies constitute important tools for diagnosing the autoimmune liver diseases (AILD) autoimmune hepatitis and primary biliary cholangitis. The EUROLINE immunoblot assay, detecting multiple specificities, is widely used, but the clinical importance of weakly positive findings is unclear. The manufacturer’s recommended cut-off was evaluated by investigating AILD-associated autoantibodies in 825 blood donors and 60 confirmed AILD cases. Positive findings were followed up with immunofluorescence microscopy on rat tissue, anti-M2-ELISA, alternative immunoblot assay, and liver function tests. Thirty-six (4.4%) blood donors were positive with EUROLINE. The most common specificities were LC-1 (1.6%), gp210 (1.3%), and AMA-M2 (1.1%). In general, the positive results were higher in patients than in blood donors, whereas anti-LC-1 was higher in blood donors. The liver function tests were slightly elevated in 2 of the 36 immunoblot positive blood donors. The majority of the positive EUROLINE findings could not be confirmed with the follow-up tests. The EUROLINE-Autoimmune Liver Diseases-(IgG) immunoblot detected autoantibodies in 4.4% of blood donors without signs of AILD. Our findings indicate that the recommended cut-off can be raised for most specificities without loss of diagnostic sensitivity. The prevalence of anti-LC-1 among blood donors indicates a problem with the antigen source.

Anti-Mitochondrial Antibody Titers Decrease Over Time in Primary Biliary Cholangitis Patients With Ursodeoxycholic Acid Therapeutic Response: A Cohort Study Followed Up to 28 Years

Background

How anti-mitochondrial antibody (AMA) and liver biochemistry levels change in primary biliary cholangitis (PBC) patients treated with ursodeoxycholic acid (UDCA) remains unclear.

Methods

A 28-year cohort of 157 PBC patients was conducted. Patients with alkaline phosphatase (Alk-p) levels >1.67 × upper limit of normal after 1 year of UDCA treatment were considered nonresponders.

Results

At baseline, of 157 (mean age: 54.41 years), 136 (86.6%) were female, 51 (32.5%) had cirrhosis, and 128 (81.5%) had detectable AMAs (immunoglobulin G). UDCA nonresponders (n=61) were younger and had higher Alk-p and total bilirubin levels and cirrhosis rates than UDCA responders (n=84). Alk-p levels and cirrhosis were negatively associated with UDCA response. Regardless of cirrhosis and UDCA response, most PBC patients had decreased Alk-p and γ-glutamyltransferase levels at last follow-up (up to 28.73 years) compared with baseline levels. Patients with baseline cirrhosis (2.78 ± 2.56 vs. 6.84 ± 9.00 mg/dL, p=0.024) and UDCA nonresponders (2.54 ± 2.19 vs. 4.51 ± 6.99 mg/dL, p=0.006) had increased total bilirubin levels while patients without cirrhosis (AST: 91.5 ± 84.5 vs. 58.9 ± 43.7 U/L, p<0.001; ALT: 107.3 ± 122.5 vs. 50.7 ± 36.8 U/L, p<0.001) and UDCA responders (AST: 83.8 ± 101.3 vs. 45.58 ± 38.42 U/L, p=0.014; ALT: 95.10 ± 144.6 vs. 39.12 ± 30.65 U/L, p=0.009) had decreased aminotransferase levels. Only UDCA responders had decreased AMA titers from 1 year after UDCA treatment (p=0.028) until the last follow-up (p<0.001).

Conclusions

UDCA responders exhibited decreased AMA titers 1 year after treatment. Regardless of UDCA response, PBC patients showed improved cholestatic features, but only UDCA responders and patients without baseline cirrhosis exhibited attenuated hepatobiliary damage following UDCA treatment.

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.

Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: Current Knowledge of Pathogenesis and Therapeutics

Cholangiopathies encompass various biliary diseases affecting the biliary epithelium, resulting in cholestasis, inflammation, fibrosis, and ultimately liver cirrhosis. Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the most important progressive cholangiopathies in adults. Much research has broadened the scope of disease biology to genetic risk, epigenetic changes, dysregulated mucosal immunity, altered biliary epithelial cell function, and dysbiosis, all of which interact and arise in the context of ill-defined environmental triggers. An in-depth understanding of the molecular pathogenesis of these cholestatic diseases will help clinicians better prevent and treat diseases. In this review, we focus on the main underlying mechanisms of disease initiation and progression, and novel targeted therapeutics beyond currently approved treatments.

Diagnostic and Clinical Value of Specific Autoantibodies against Kelch-like 12 Peptide and Nuclear Envelope Proteins in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the presence of antimitochondrial and antinuclear antibodies in patients’ serum. Here, we analyzed the reactivity of autoantibodies against a novel autoantigen, kelch-like 12 (KLHL12) protein, in a cohort of 138 PBC and 90 non-PBC patients. Additionally, we compared the reactivity of KLHL12 with antinuclear envelope antibodies: anti-gp210, anti-p62, and anti-LBR. Commercially available kits and an ‘in-house’ ELISA were used in the studies. Antinuclear envelope antibodies were detected in 65% of PBC patients and the presence of these antibodies was observed more frequently in patients diagnosed with later stages (III/IV) of PBC, according to Ludwig’s classification (p < 0.05) and were found to correlate with a higher concentration of bilirubin. Overall, anti-KLHL12 antibodies were found more frequently in PBC patients than in non-PBC controls (p < 0.001). Anti-KLHL12 antibodies were detected in 36% of the tested PBC cohort, including PBC patients negative for antimitochondrial antibodies. Presence of anti-KLHL12 was also associated with a higher concentration of bilirubin and correlated with fibrosis (p < 0.05). Anti-KLHL12 antibodies were detected in 30% of PBC individuals positive for antinuclear envelope antibodies, while anti-KLHL12 and antinuclear envelope antibodies were found in 17% of all PBC cases. Concluding, our data confirm that antibodies against the KLHL12 protein are highly specific for PBC and when used in combination with other markers, may significantly increase the diagnosis of PBC.

Alterations in gut microbiota and elevated serum bilirubin in primary biliary cholangitis patients treated with ursodeoxycholic acid

BACKGROUND

The prognosis of primary bile cholangitis (PBC) is linked to gut microbiota dysbiosis. This study investigated the association between the gut microbiome and elevated total bilirubin (TB) level in PBC patients treated with ursodeoxycholic acid (UCDA).

METHODS

A total of 47 PBC patients with 12 months of UCDA treatment were enrolled. Patients were divided into the TB (+) (TB>1× upper limit of the normal range [ULN]; n = 20) and TB(-) (TB≤1× ULN; n = 27) groups. Stool and serum specimens were collected, and microbiota composition and functional characteristics in the 2 groups were evaluated by 16S RNA gene sequencing and bioinformatic analysis.

RESULTS

Bacterial diversity was lower in the TB(+) group than in the TB(-) group, although there was no significant difference in bacterial community profile. The phylum Saccharibacteria showed differential abundance in the 2 groups. Meanwhile, the TB(-) group had lower abundance of the Gemmiger, Blautia, Anaerostipes and Coprococcus genera than the TB(+) group, whereas Holdemania was absent. The abundance of Gemmiger formicillis and Coprococcus eutactus was positively correlated with that of Faecalibacterium prausnitzii, while Blautia, Anaerostipes and Coprococcus were negatively correlated with total bile acid level.

CONCLUSION

TB level in PBC patients treated for 12 months with UCDA is associated with a distinct gut microbiome profile.

Antimitochondrial Antibodies: from Bench to Bedside

Anti-mitochondrial antibodies (AMA) are directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes (PDC-E2) and are the typical biomarkers of primary biliary cholangitis (PBC), being present in 90-95% of patients, with increasing sensitivity at increasing titers. Albeit being highly specific for PBC diagnosis, AMA can be detected in less than 1% of healthy subjects, and thus the management subjects with no sign or symptom of liver disease is still a challenge and data concerning clinical risk of developing PBC in this subgroup of patients are controversial. Moreover, AMA can also be detected in patients affected by overlap syndrome, as well as hepatic diseases (i.e., NASH and viral hepatitis), while the association with autoimmune diseases, in particular Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus, is well established. Furthermore, new associations are being identified with inflammatory myositis and heart disease. AMA are directed towards the pyruvate dehydrogenase multi enzyme complex (PDC-E2) subunit, which represents an epithelial specific autoantigen for PBC. This review focuses on the main characteristics of AMA, their association with autoimmune diseases and liver diseases.

Management of primary biliary cholangitis: results from a large real-life observational study in France and Belgium

BACKGROUND AND AIMS

To assess the characteristics, care, treatment response, and outcomes of primary biliary cholangitis (PBC) patients recently followed-up by hepato-gastroenterologists in various French and Belgian healthcare settings.

METHODS

This retrospective cohort study included patients with PBC who recently visited 79 hepato-gastroenterologists in France and Belgium. Data were collected at the time of diagnosis and at last visit and were compared according to biochemical response (BR) to ursodeoxycholic acid (UDCA) (BR), using Paris I-II criteria, and clinical outcomes.

RESULTS

A total of 436 patients (mean age at diagnosis 57 years, 88% females, median follow-up 5.2 years) were included. Liver biopsy, transient elastography, or none of these two procedures were performed at baseline in 216 (50%), 194 (45%), and 107 (25%) patients, respectively. Late-stage disease (histological stage III or IV, or transient elastography ≥9.6 kPa, or bilirubin >17 µM and albumin <35 g/L, or platelets <150.000/µl, or unequivocal signs of portal hypertension or cirrhosis) was reported in 37% of patients. UDCA was taken by 95% of patients (27% had suboptimal dosage). Inadequate BR was observed in 37% of patients. Clinicians overestimated disease control. Liver-related complications occurred in 9% of patients. Bilirubin and albumin independently predicted inadequate BR; advanced disease stage and inadequate BR independently predicted complications.

CONCLUSIONS

Recently followed-up French and Belgian patients with PBC had homogeneous management. Late stage at diagnosis and inadequate BR were reported in around 40% of patients. Disease control was frequently overestimated by clinicians. Disease stage and BR were the main prognostic factors.

Definition and Management of Patients With Primary Biliary Cholangitis and an Incomplete Response to Therapy

Primary biliary cholangitis (PBC) is an immune-mediated chronic liver disease characterized by biliary epithelial injury, cholestasis, and progressive fibrosis that can lead to cirrhosis and requirement for liver transplantation. All patients with PBC should receive initial treatment with ursodeoxycholic acid (UDCA), and odds for response are based on characteristics at baseline. It is important to have clear definitions of patients at risk for a poor response to therapy, of biochemical markers of an incomplete response, and standardized management. Patients typically are assessed after 12 months of treatment with UDCA for biochemical markers of response. However, evaluation at 6 months has been proposed for patients with more severe disease or symptoms (such as pruritus or fatigue). Markers of response to therapy include reduced serum levels of alkaline phosphatase and bilirubin (Paris-2, Toronto, GLOBE, and so forth); patients with high levels of total and conjugated bilirubin or levels of alkaline phosphatase more than 1.5-fold the upper limit of normal should be considered for second-line therapy. Patients with adequate biochemical responses can continue UDCA monotherapy. Incomplete responders should be considered for second-line therapies with obeticholic acid (licensed) or fibrates (unlicensed) in addition to continued treatment with UDCA. Patients with PBC should be followed up for life.

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.

The pathogenesis, models and therapeutic advances of primary biliary cholangitis

Primary biliary cholangitis (PBC) is an autoimmune disease characterized by the destruction of intrahepatic small bile ducts and the presence of antimitochondrial antibody (AMA), eventually progresses to liver fibrosis and cirrhosis. Genetic predisposition and environmental factors are involved in the occurrence of PBC, and the epitopes exposure and the imbalance of autoimmune tolerance are the last straw. The apoptosis of biliary epithelial cell (BEC) leads to the release of autoantigen epitopes, which activate the immune system, and the disorder of innate and adaptive immunity eventually leads to the start of disease. Animal models have unique advantages in investigating the pathogenesis and drug exploitation of PBC. Multiple models have been reported, and spontaneous model and induced model have been widely used in relevant research of PBC in recent years. Currently, the only drugs licensed for PBC are ursodesoxycholic acid (UDCA) and obeticholic acid (OCA). In the last few years, as the learned more about the pathogenesis of PBC, more and more targets have been discovered, and multiple targeted drugs are being in developed. In this review, the pathogenesis, murine models and treatment strategies of PBC were summarized, and the current research status was discussed to provide insights for the further study of PBC.

Fibrotic Events in the Progression of Cholestatic Liver Disease

Cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are associated with active hepatic fibrogenesis, which can ultimately lead to the development of cirrhosis. However, the exact relationship between the development of liver fibrosis and the progression of cholestatic liver disease remains elusive. Periductular fibroblasts located around the bile ducts seem biologically different from hepatic stellate cells (HSCs). The fibrotic events in these clinical conditions appear to be related to complex crosstalk between immune/inflammatory mechanisms, cytokine signalling, and perturbed homeostasis between cholangiocytes and mesenchymal cells. Several animal models including bile duct ligation (BDL) and the Mdr2-knockout mice have improved our understanding of mechanisms underlying chronic cholestasis. In the present review, we aim to elucidate the mechanisms of fibrosis in order to help to identify potential diagnostic and therapeutic targets.

Detection of anti-mitochondrial 2-oxoacid dehydrogenase complex subunit's antibodies for the diagnosis of primary biliary cholangitis

Anti-mitochondrial antibodies (AMA), directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes, are markers of Primary Biliary Cholangitis (PBC), a chronic autoimmune liver disease. However, the clinical significance of subunits-specific AMA type PDC-E2 -E2 subunit of the pyruvate dehydrogenase complex-, BCOADC-E2 -E2 subunit of the branched-chain 2-oxo acid dehydrogenase complex-, OGDC-E2 -E2 subunit of the 2-oxo-glutarate dehydrogenase complex- and nPDC -native pyruvate dehydrogenase complex (M2-AMA) . Is not well known, and not all AMA specificities are associated with PBC. The aim of the study was to show the usefulness of the number and combination of subunits-specific AMA positive for the diagnosis of PBC. We detected AMA by indirect immunofluorescence (IIF-AMA) and M2-AMA by dot-blot. We studied the relationship of AMA with some clinical and laboratory variables in 307 patients (37% PBC) with positive dot-blot for M2-AMA. In PBC patients, we detected different E2 subunits of the 2-oxo acid dehydrogenase complexes antibodies (M2-AMA): 82.9% were specific for nPDC, 64.5% for PDC-E2, 44.4% for BCOADC-E2, and 9.6% for OGDC-E2. IIF and dot-blot tests achieved a Area Under the Receiver Operating Characteristic Curve (ROC AUC) of 0.674 (1: 320 cut-off titer, Sensibility (Se) 64.7%, Specificity (Sp) 63.4%) and 0.663 (three specificities M2-AMA, Se 43%, Sp 81.2%), respectively. The detection of different E2 subunits of the 2-oxo acid dehydrogenase complexes antibodies (M2-AMA) by dot-blot showed different ROC AUC: anti-PDC-E2 showed an AUC of 0.610, a Se of 43.7%, and a Sp of 76.4%. Finally, the combined detection of nPDC/BCOADC-E2/PDC-E2 reached an AUC of 0.6095, a Se of 59.6%, and a Sp of 70.2%.The identification of two M2-AMA specificities through dot-blot increased PBC odds ratio (OR) by 2.05 (p:0.031), as compared to the identification of one specificity. Moreover, the identification of three and four specificities increased OR by 4.63 (p:0.000) and by 21.53 (p:0.006), respectively. nPDC/OGDC-E2/PDC-E2 and nPDC/OGDC-E2/BCOADC-E2/PDC-E2 combinations increased PBC OR by 10.04 (p:0.034), as compared to any other combination. 1:320 and 1:640 IIF-AMA increased PBC OR by 4.93 (p:0.009) and 7.67 (p:0.001), respectively, as compared to IIF-AMA titers equal to or less than 1:160. M2-AMA dot-blot was less sensitive but more specific than IIF-AMA, with similar predictive capacity for PBC. Increased numbers of M2-AMA specificities clearly increased the risk of PBC. Some combinations were strongly related to PBC (nPDC/BCOADC-E2/PDC-E2), but others were not (one single M2-AMA, and nPDC plus PDC-E2). M2-AMA dot-blot was less sensitive but more specific than IIF-AMA, with similar predictive capacity for PBC. Increased numbers of M2-AMA specificities clearly increased the risk of PBC, being some combinations, such as nPDC/BCOADC-E2/PDC-E2, more related to PBC than others. Finally, the determination of the number of M2-AMA specificities was more useful than the particular subunit target for PBC diagnosis. In conclusion, the study of the number of M2-AMA specificities by dot-blot should definitely be considered for PBC diagnosis.

Anti-mitochondrial autoantibodies are associated with cardiomyopathy, dysphagia, and features of more severe disease in adult-onset myositis

We analyzed the prevalence of anti-mitochondrial autoantibodies (AMA) in adult- and juvenile-onset myositis longitudinal cohorts and investigated phenotypic differences in myositis patients with AMA. We screened sera from myositis patients including 619 adult- and 371 juvenile-onset dermatomyositis (DM, JDM), polymyositis (PM, JPM), inclusion body myositis (IBM), or amyopathic DM patients and from healthy controls, including 164 adults and 92 children, for AMA by ELISA. Clinical characteristics were compared between myositis patients with and without AMA. AMA were present in 5% of adult myositis patients (16 of 216 DM, 10 of 222 PM, 4 of 140 IBM, 1 of 19 amyopathic DM), 1% of juvenile myositis patients (3 of 302 JDM, 1 of 25 JPM), and 1% of both adult and juvenile healthy controls. In patients with adult-onset myositis, AMA were associated with persistent muscle weakness, Raynaud’s phenomenon, dysphagia, and cardiomyopathy. Adult myositis patients with AMA may have more severe or treatment refractory disease, as they more frequently received glucocorticoids and intravenous immunoglobulin. In juvenile myositis, children with AMA often had falling episodes and dysphagia, but no other clinical features or medications were significantly associated with AMA. AMA are present in 5% of adult myositis patients and associated with cardiomyopathy, dysphagia, and other signs of severe disease. The prevalence of AMA is not increased in patients with juvenile myositis compared to age-matched healthy controls. Our data suggest that the presence of AMA in adult myositis patients should prompt screening for cardiac and swallowing involvement.

Key Points • Approximately 5% of a large North American cohort of adult myositis patients have anti-mitochondrial autoantibodies. • Adults with anti-mitochondrial autoantibodies often have chronic weakness, Raynaud’s, dysphagia, cardiomyopathy, and more severe disease. • Anti-mitochondrial autoantibodies are rare in juvenile myositis and not associated with a specific clinical phenotype.

Cholestatic liver disease: Practice guidelines from the Saudi Association for the Study of Liver diseases and Transplantation

Cholestatic liver diseases (CLDs) are a group of diseases characterized by jaundice and cholestasis as the main presentation with different complications, which have considerable impact on the liver and can lead to end-stage liver disease, cirrhosis, and liver-related complications. In the last few years, tremendous progress has been made in understanding the pathophysiology, diagnosis, and treatment of patients with these conditions. However, several aspects related to the management of CLDs remain deficient and unclear. Due to the lack of recommendations that can help in the management, treatment of those conditions, the Saudi Association for the Study of Liver diseases and Transplantation (SASLT) has created a task force group to develop guidelines related to CLDs management in order to provide a standard of care for patients in need. These guidelines provide general guidance for health care professionals to optimize medical care for patients with CLDs for both adult and pediatric populations, in association with clinical judgments to be considered on a case-by-case basis. These guidelines describe common CLDs in Saudi Arabia, with recommendations on the best approach for diagnosis and management of different diseases based on the Grading of Recommendation Assessment (GRADE), combined with a level of evidence available in the literature.

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.

Diagnosis and treatment of primary biliary cholangitis

Primary biliary cholangitis is a cholestatic, chronic autoimmune liver disease with a wide individual variation in disease progression. The diagnosis is predominantly based on chronic elevation of alkaline phosphatase and the presence of anti-mitochondrial antibodies or other specific antinuclear antibodies (i.e. anti-gp210 and anti-sp100). Even in early-stage disease, health-related quality of life can be severely impaired by symptoms such as pruritus, fatigue, and sicca syndrome and metabolic bone disease should be assessed and treated. The prognosis of the disease is, however, largely determined by the development of cirrhosis and its complications. Ursodeoxycholic acid is associated with an improved prognosis and should be initiated and continued in all patients. Clinical outcome is related to the biochemical response to ursodeoxycholic acid, but the prognosis of those with an incomplete response is still better than those who remain untreated. Obeticholic acid was recently approved as second-line treatment and bezafibrate may serve as an adequate off-label alternative, particularly in patients with pruritus. Preliminary data suggest an additive effect of triple therapy with ursodeoxycholic acid, obeticholic acid, and bezafibrate, whereas other promising drugs are being evaluated in clinical trials.

Low rate of new-onset primary biliary cholangitis in a cohort of anti-mitochondrial antibody-positive subjects over six years of follow-up

BACKGROUND AND AIMS

Anti-mitochondrial antibodies (AMA) are closely linked to primary biliary cholangitis (PBC). The prevalence of AMA in the general population is low, and AMA positivity may precede PBC. We aimed to determine the natural history of subjects with positive AMA.

METHODS

In total, 302 patients were tested AMA-positive over a ten-year period. Of these, immunoblotting confirmed specific AMA in 184 (29 male, 155 female, age 59.6 ± 14.1 years). These subjects were invited to our liver outpatient clinic for clinical and biochemical re-evaluation. Detailed clinical history data were additionally collected from the hospital computer system and by telephone. The subsequent course with regard to mortality, liver-related morbidity, extrahepatic co-morbidities and effectiveness of PBC treatment was determined in 150 subjects (81.5%).

RESULTS

After 5.8 ± 5.6 years of follow-up (FU), of 184 AMA-positive subjects, 28 subjects (15.2%; liver-related mortality n = 5) were deceased, and 122 subjects (66.3%) completed FU while 34 subjects (18.5%) were not available for FU. The 122 patients who completed FU were 63 patients with established PBC, six de novo cases of PBC (10.2% of 59 initially at risk), 42 (34.4%) subjects were still AMA-positive without PBC, and 11 (9.0%) subjects were AMA-negative at FU.

CONCLUSIONS

Anti-mitochondrial antibodies-positive patients without PBC at baseline infrequently developed PBC over six years of FU. AMA positivity represented a transient serological autoimmune phenomenon in a significant proportion of subjects.

Inflammation: Cause or consequence of chronic cholestatic liver injury

Cholestasis is a result of obstruction of the biliary tracts. It is a common cause of liver pathology after exposure to toxic xenobiotics and during numerous other liver diseases. Accumulation of bile acids in the liver is thought to be a major driver of liver injury during cholestasis and can lead to eventual liver fibrosis and cirrhosis. As such, current therapy in the field of chronic liver diseases with prominent cholestasis relies heavily on increasing choleresis to limit accumulation of bile acids. Many of these same diseases also present with autoimmunity before the onset of cholestasis though, indicating the inflammation may be an initiating component of the pathology. Moreover, cytotoxic inflammatory mediators accumulate during cholestasis and can propagate liver injury. Anti-inflammatory biologics and small molecules have largely failed clinical trials in these diseases though and as such, targeting inflammation as a means to address cholestatic liver injury remains debatable. The purpose of this review is to understand the different roles that inflammation can play during cholestatic liver injury and attempt to define how new therapeutic targets that limit or control inflammation may be beneficial for patients with chronic cholestatic liver disease.