Clinical significance of the fluctuation of primary biliary cirrhosis-related autoantibodies during the course of the disease

Immunosuppression induces regression of fibrosis in primary biliary cholangitis with moderate-to-severe interface hepatitis

BACKGROUND

In patients with primary biliary cholangitis (PBC) treated with ursodeoxycholic acid (UDCA), the presence of moderate-to-severe interface hepatitis is associated with a higher risk of liver transplantation and death. This highlights the need for novel treatment approaches. In this study, we aimed to investigate whether combination therapy of UDCA and immunosuppressant (IS) was more effective than UDCA monotherapy.

METHODS

We conducted a multicenter study involving PBC patients with moderate-to-severe interface hepatitis who underwent paired liver biopsies. Firstly, we compared the efficacy of the combination therapy with UDCA monotherapy on improving biochemistry, histology, survival rates, and prognosis. Subsequently we investigated the predictors of a beneficial response.

RESULTS

This retrospective cohort study with prospectively collected data was conducted in China from January 2009 to April 2023. Of the 198 enrolled patients, 32 underwent UDCA monotherapy, while 166 received combination therapy, consisting of UDCA combined with prednisolone, prednisolone plus mycophenolate mofetil (MMF), or prednisolone plus azathioprine (AZA). The monotherapy group was treated for a median duration of 37.6 months (IQR 27.5-58.1), and the combination therapy group had a median treatment duration of 39.3 months (IQR 34.5-48.8). The combination therapy showed a significantly greater efficacy in reducing fibrosis compared to UDCA monotherapy, with an 8.3-fold increase in the regression rate (from 6.3% to 52.4%, P < 0.001). Other parameters, including biochemistry, survival rates, and prognosis, supported its effectiveness. Baseline IgG >1.3 × ULN and ALP <2.4 × ULN were identified as predictors of regression following the combination therapy. A predictive score named FRS, combining these variables, accurately identified individuals achieving fibrosis regression with a cut-off point of ≥ -0.163. The predictive value was validated internally and externally.

CONCLUSION

Combination therapy with IS improves outcomes in PBC patients with moderate-to-severe interface hepatitis compared to UDCA monotherapy. Baseline IgG and ALP are the most significant predictors of fibrosis regression. The new predictive score, FRS, incorporating baseline IgG and ALP, can effectively identify individuals who would benefit from the combination therapy.

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.

Clinical performance of AMA-M2, anti-gp210 and anti-sp100 antibody levels in primary biliary cholangitis: When detected by multiplex bead-based flow fluorescent immunoassay

BACKGROUND AND AIM

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy, characterized by the presence of some autoantibodies in the serum. This study aimed to evaluate the clinical significance of AMA-M2, anti-gp210 and anti-sp100 antibody levels detected by multiplex bead-based flow fluorescent immunoassay (MBFFI) in PBC.

METHODS

This study cohort included 238 PBC patients, 81 autoimmune hepatitis (AIH) patients, 62 systemic lupus erythematosus (SLE) patients, and 118 healthy controls. Serum AMA-M2, anti-gp210 and anti-sp100 antibody were detected by MBFFI and immunoblotting assay (IBT). The relationship between three antibody levels and cirrhosis, liver function, cholestasis markers and therapeutic effect to ursodesoxycholic acid (UDCA) was evaluated in PBC.

RESULTS

MBFFI were presented good coincidence rate (87.39%-95.38%) with IBT. The level of AMA-M2, anti-gp210 and anti-sp100 antibodies in PBC patients were higher than other disease group and healthy controls (p ＜ .01). When compared with the healthy controls group, the AUC of AMA-M2, anti-gp210 and anti-sp100 antibodies were 0.9245, 0.7619, and 0.6789, respectively. In addition, gp210 antibody levels have diagnostic value in patients with liver cirrhosis (AUC: 0.7567). We found that when combine detect these three antibodies, the sensitivity was higher than individually detection. High level of serum anti-gp210 antibody could be related to worse liver function and more severe cholestasis in PBC patients. Moreover, serum antibody levels may decrease or remained flat in patients who responded well to UDCA.

CONCLUSION

The detection of AMA-M2, anti-gp210 and anti-sp100 antibody levels by MBFFI showed good performance in the diagnosis of PBC. Serum anti-gp210 antibody level is related to cirrhosis, poor liver function and severe cholestasis in PBC.

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.

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.

Correlation between individual autoantibodies and clinical features in primary biliary cholangitis: results of a retrospective longitudinal study

BACKGROUND AND AIMS

Primary biliary cholangitis (PBC) is an immune-mediated liver disease. The immunological profile seems to relate to clinical prognosis. This study aims to determine the role of autoantibodies in the course of liver disease and in the response to ursodeoxycholic acid.

METHODS

Between January 2016 and December 2020, 143 patients with PBC who underwent immunological liver profile evaluation were enrolled. All data were extracted retrospectively from electronic clinical records. Chi-square test, Fisher's exact test and Mann-Whitney test were used to evaluate the relationship between autoantibodies and biochemical parameters, clinical outcomes and therapeutic response scores. A significance level of 0.05 was used.

RESULTS

Antimitochondrial antibodies were present in 91.6%, antiglycoprotein-210 antibody (anti-gp210) in 18.2% and anti-Sp100 in 19.6% of patients. The incidence of liver-related death was higher in patients with autoimmune hepatitis variants. The occurrence of cirrhosis or portal hypertension was not linked to the presence of any of the autoantibodies tested. No relationship was found with the probability of dying or being transplanted. Patients with anti-Sp100 antibodies had higher baseline levels of aspartate aminotransferase and alanine aminotransferase and lower immunoglobulin M levels. Patients with anti-gp210 were more likely to have a lower median transplant-free survival rate and higher median risk of liver transplant or liver-related death using the GLOBE and UK-PBC scores.

CONCLUSION

Our findings confirm a strong association between anti-gp210 antibodies and a worse outcome. The association between anti-Sp100 and hepatic lesions requires further elucidation.

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.

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.

Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis

Diagnosis of autoimmune hepatitis (AIH) is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the disease. The clinical spectrum of AIH varies from completely asymptomatic to acute-severe or even rarely fulminant hepatic failure, while everybody can be affected irrespective of age, gender, and ethnicity. The old revised and the newer simplified diagnostic scores have been established by the International Autoimmune Hepatitis Group (IAIHG) in 1999 and 2008, respectively, which are based on several clinical, laboratory and histological parameters. Additionally, a thorough differential diagnosis from other diseases mimicking AIH is absolutely indicated. In this context, autoantibodies detection in patients with suspected AIH is mandatory -even though not pathognomonic- not only for AIH diagnosis but furthermore, for AIH classification (AIH-type 1 and AIH-type 2). Although autoimmune serology can be supportive of AIH diagnosis in ≥95% of cases if testing has been performed according to the IAIHG guidelines, this is not the case under real-life circumstances in routine clinical laboratories. Clinicians should be careful both for the importance of the required testing and how to interpret the results and therefore, they should communicate and discuss with the laboratory personnel to achieve the maximum benefit for the patient. Herein, a detailed and updated review of the diagnostic work-up for AIH diagnosis under real-life conditions is given to minimize the underestimation and misdiagnosis of AIH which can result in progression of the disease and unfavourable outcomes.

An Assessment of the Serum Activity of ADH and ALDH in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC; previously known as primary biliary cirrhosis) is a chronic inflammation-induced cholestatic process in the liver. Antimitochondrial antibodies (AMAs) are observed in around 90% of patients, which suggests that PBC is an autoimmune disease. Alcohol dehydrogenase (ADH), ADH isoenzymes and aldehyde dehydrogenase (ALDH) are localized in the liver, and they are useful markers of liver dysfunction. In this study, the activity of total ADH, ADH isoenzymes and ALDH was evaluated in the blood serum of patients with PBC. The experimental group comprised 50 PBC patients, both male and female, aged 28-67. The control group consisted of 50 healthy subjects, both male and female, aged 25-65. The serum activity of class I ADH, class II ADH and ALDH was measured by spectrofluorophotometry, whereas total ADH and class III ADH activity was determined by photometry methods. The activity of class I ADH and total ADH was significantly higher in the experimental group than in the control group (p < 0.001). An increase in class I ADH and total ADH activity indicates that the isoenzyme class I ADH is released by compromised liver cells and can be useful diagnostic markers of PBC.

Incomplete response to ursodeoxycholic acid in primary biliary cholangitis: criteria, epidemiology, and possible mechanisms

INTRODUCTION

As a common autoimmune disease with the characteristic of early complication, primary biliary cholangitis (PBC) leads to an increasing number of mortalities among people with end-stage liver disease (ESLD) waiting for liver transplantation. Ursodeoxycholic acid (UDCA) is the only approved first-line medicine for PBC, and a good response to treatment could acquire an ideal prognosis. Patients with poor UDCA response usually have more adverse outcomes and worse survival, therefore, the management of this group become a major consideration.

AREAS COVERED

Due to the complexity of race and environment for PBC, different criteria for UDCA response exhibit various predictive performances. Factors affecting UDCA response conditions include gender, age, ethnicity, serum indicators, auto-antibodies, and autoimmune comorbidities, while no agreement has been reached. In this review, we mainly focus on cellular senescence, immune-mediated damage, and vitamin D deficiency as possible mechanisms for UDCA non-responders.

EXPERT OPINION

The pathogenesis of PBC has yet to be clarified. Immunology-related mechanisms and therapy targets ought to be the main effort made for further study. Irrespective of the response condition, UDCA is recommended for routine administration in all PBC patients without contraindication. Ongoing clinical trials of second-line and additional therapy exhibit promising prospects.

Optimization of Laboratory Diagnostics of Primary Biliary Cholangitis: When Solid-Phase Assays and Immunofluorescence Combine

The laboratory diagnostics of primary biliary cholangitis (PBC) have substantially improved, thanks to innovative analytical opportunities, such as enzyme-linked immunosorbent assays (ELISA) and multiple immunodot liver profile tests, based on recombinant or purified antigens. This study aimed to identify the best diagnostic test combination to optimize PBC diagnosis. Between January 2014 and March 2017, 164 PBC patients were recruited at the hospitals of Parma, Modena, Reggio-Emilia, and Piacenza. Antinuclear antibodies (ANA) and anti-mitochondrial antibodies (AMA) were assayed by indirect immunofluorescence (IIF), ELISA, and immunodot assays (PBC Screen, MIT3, M2, gp210, and sp100). AMA-IIF resulted in 89.6% positive cases. Using multiple immunodot liver profiles, AMA-M2 sensitivity was 94.5%, while anti-gp210 and anti-sp100 antibodies were positive in 16.5% and 17.7% of patients, respectively. PBC screening yielded positive results in 94.5% of cases; MIT3, sp100, and gp210 were detected by individual ELISA test in 89.0%, 17.1%, and 18.9% of patients, respectively. The association of PBC screening with IIF-AMA improved the diagnostic sensitivity from 89.6% to 98.2% (p < 0.01). When multiple immunodot liver profile testing was integrated with AMA-IIF, the diagnostic sensitivity increased from 89.1% to 98.8% (p < 0.01). The combination of IIF with solid-phase methods significantly improved diagnostic efficacy in PBC patients.

Peroxisome Proliferator-Activated Receptors Regulate Hepatic Immunity and Assist in the Treatment of Primary Biliary Cholangitis

Fibrates, which are agonists of peroxisome proliferator-activated receptor alpha, have received increasing attention in the treatment of primary biliary cholangitis. Reduced alkaline phosphatase levels and improved clinical outcomes were observed in patients with primary biliary cholangitis with an inadequate response to ursodeoxycholic acid (UDCA) monotherapy4 when treated with bezafibrate or fenofibrate combined with UDCA. In contrast to obeticholic acid, which exacerbates pruritus in patients, fibrates have been shown to relieve pruritus. Clinical trial outcomes show potential for the treatment of primary biliary cholangitis by targeting peroxisome proliferator-activated receptors. It is currently agreed that primary biliary cholangitis is an autoimmune-mediated cholestatic liver disease, and peroxisome proliferator-activated receptor is a nuclear receptor that regulates the functions of multiple immune cells, thus playing an important role in regulating innate and adaptive immunity. Therefore, this review focuses on the immune disorder of primary biliary cholangitis and summarizes the regulation of hepatic immunity when peroxisome proliferator-activated receptors are targeted for treating primary biliary cholangitis.

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.

Clinical impact of antibodies to Sp100 on a bacterial infection in patients with primary biliary cholangitis

BACKGROUND

A specific antinuclear antibody for primary biliary cholangitis (PBC) is anti-Sp100, which was recognized as a serological marker of concurrent urinary tract infection. We sought to determine the clinical characteristics of PBC patients who had anti-Sp100.

PATIENTS AND METHODS

Fifty-one patients with PBC and 10 healthy controls (HCs) were enrolled. Anti-Sp100 were determined with an ELISA method. Lipopolysaccharide-binding protein (LBP) was measured as a serological hallmark for bacterial infection. The correlations of anti-Sp100 with demographic, laboratory, and pathological parameters were investigated.

RESULTS

Six of the 51 (11.8%) PBC patients had anti-Sp100, whereas none of the HCs did. There was no significant difference in the frequency of antimitochondrial antibodies (AMAs) between PBC patients with and without anti-Sp100 (67% vs. 82%, p = 0.5839). Biochemical and immunological parameters were not associated with the emergence of anti-Sp100 in these patients. The clinical stage by Scheuer classification was not correlated with the existence of anti-Sp100. No significant difference in the serum LBP levels was found between PBC patients with and without anti-Sp-100, although serum LBP levels were significantly higher in PBC patients with anti-Sp100 than in HCs (8.30 ± 2.24 ng/ml, vs. 5.12 ± 2.48 ng/ml, p = 0.0022). The frequency of granuloma formation was higher in the liver specimens of PBC patients with anti-Sp100 than in those without anti-Sp100 (67% vs 29%, p = 0.0710).

CONCLUSION

anti-Sp100 does not become a complementary serological marker for PBC in AMA-negative patients. A bacterial infection may trigger the production of anti-Sp100. Another factor is required to initiate the autoantibody production.

Anti-gp210 and anti-Sp100 antibodies in primary biliary cholangitis

BACKGROUND AND STUDY AIMS

To determine the sensitivity and specificity of anti-gp210 and anti-Sp100 autoantibodies in primary biliary cholangitis (PBC) PATIENTS AND METHODS: Sera of 106 PBC patients with positive anti-mitochondrial antibodies and 58 healthy blood donors were analyzed. A line immunoassay was used to evaluate the reactivity of anti-gp210 and anti-Sp100 antibodies.

RESULTS

The frequency of anti-gp210 and anti-Sp100 autoantibodies was 29.2% and 28.3%, respectively. Eight patients had both anti-gp210 and anti-Sp100 antibodies. Of 106 patients, 23 (21.7%) had anti-gp210 antibody, although not anti-Sp100 antibody, and 22 (20.7%) had anti-Sp100, although not anti-gp210 antibodies. Their combination increased the frequency of anti-gp210 and anti-Sp100 antibodies from 29.2% to 50% (P = 0.002) and 28.3% to 50% (P = 0.0012), respectively. In the control group, two subjects had anti-gp210 antibody and none had anti-Sp100 antibody. Thus, the specificity of anti-gp210 and anti-Sp100 antibodies was 96.5% and 100%, respectively. The positive predictive value (PPV) of anti-gp210 antibody was 94%; its negative predictive value (NPV) was 42.7%. The PPV and NPV of anti-Sp100 antibody were 100% and 43.3%, respectively.

CONCLUSION

It is important to combine anti-gp210 and anti-Sp100 antibodies in the immunological exploration of PBC.

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.

Promyelocytic Leukemia Antigen Expression: a Histological Marker for Primary Biliary Cholangitis Diagnosis?

Background and Objectives

Distinguishing primary biliary cholangitis (PBC) from other cholestatic diseases at the histological level could be assisted by new methods, such as immunohistochemical staining of specific antigens.

Methods

We evaluated whether the detection of promyelocytic leukemia protein (PML) can serve as a specific and sensitive marker for PBC diagnosis. Liver biopsies from 26 PBC patients, 20 primary sclerosing cholangitis (PSC), 37 viral hepatitis, 11 non-alcoholic steatohepatitis (NASH) and 5 normal patients were investigated after immunostaining with the anti-PML monoclonal PG-M3, IgG1 antibody.

Results

Immunoreactivity in bile ducts was expressed by the PML-score (quotient of positive ducts to the total number of portal tracts multiplied by 2). PML-score was higher in PBC as compared to controls (P < 0.001). Using a cutoff of 0.18, PML-score proved highly sensitive (84.6%) and specific (89.7%) for confirming PBC as compared to only 5% of PSC, 9.1% of NASH and 13.5% of viral hepatitis patients (P < 0.001). Irrespective of the underlying disease, patients with PML-score > 0.18 were older (P = 0.007), more often females (P < 0.001) with higher ALP (P < 0.001), γ-GT (P = 0.001) and IgM (P < 0.001) compared to the patients with PML-score < 0.18.

Conclusions

We postulate that a simple PML immunohistochemical test could be sufficient for histopathological discrimination of PBC in problematic cases of undefined cholestatic disorders, including small-duct PSC and AMA-negative PBC cases.

Antibodies to gp210 and understanding risk in patients with primary biliary cholangitis

BACKGROUND AND AIMS

A variety of auto-antibody assays are available as part of the clinical care of patients with liver disease. We sought to better understand the clinical utility of immune serological testing in patients with primary biliary cholangitis (PBC).

METHODS

We retrospectively analysed data from 2846 patients investigated for liver disease at a UK liver centre between 2001 and 2017. A total of 499 patients with PBC were identified. Immune serology results were examined for their diagnostic utility and prognostic significance to predict transplant-free survival.

RESULTS

Antimitochondrial antibodies (AMAs) were specific (94.5%) and sensitive (85.6%) for PBC; antinuclear antibodies (ANAs) against glycoprotein 210 (gp210) and sp100 were specific (>98%) but not sensitive (<25%). The disease-specific ANAs were detectable in 29.6% of AMA-negative patients. Anti-gp210 auto-antibodies were significantly associated with elevated serum aminotransferase activity, bilirubin and liver stiffness at presentation (P < .010). Anti-gp210 auto-antibodies predicted non-response to ursodeoxycholic acid (UDCA) by GLOBE criteria (39.3% vs 16.7%, P = .005). Moreover, anti-gp210 was independently associated with death or liver transplantation (HR 3.22, 95% CI 1.49-6.96; P = .003), after accounting for other significant baseline determinants of outcome. Serologic finding of anti-gp210 antibodies conferred an independent risk of death or transplantation (HR 4.13, 95% CI 1.85-9.22; P = .001) after accounting for treatment response.

CONCLUSION

In our single-centre cohort of patients with PBC, the presence of anti-gp210 was associated with an adverse presenting phenotype, predicted treatment non-response and independently predicted reduced transplant-free survival.

Role of Antinuclear Antibodies in Primary Biliary Cholangitis

The identification of antinuclear antibodies specific for primary biliary cholangitis (PBC) has facilitated diagnosis in antimitochondrial antibody-negative individuals. Their presence may also have prognostic implication. In this edition of The American Journal of Gastroenterology, Reig et al. evaluate the frequency of PBC-specific antinuclear antibodies, their natural course and association with outcomes in 254 patients with PBC. Antibodies remained stable over time, and presence of antihexokinase1 and anti-sp100 was associated with shorter survival. Clinicians can request testing for PBC-specific antinuclear antibodies to minimize need for liver biopsy, but further research is needed to understand their role in disease prognostication.

Novel Anti-Hexokinase 1 Antibodies Are Associated With Poor Prognosis in Patients With Primary Biliary Cholangitis

INTRODUCTION

Antibodies to hexokinase 1 (HK1) and kelch-like 12 (KLHL12) have been identified as potential biomarkers in primary biliary cholangitis (PBC), and this study assesses changes of these antibodies over time and if they are associated with clinical outcomes.

METHODS

Two hundred fifty-four PBC patients (93.3% female, 51 ± 12.3 years old) were tested for anti-HK1 and anti-KLHL12, antimitochondrial (AMA), anti-gp210, and anti-sp100 antibodies. One hundred sixty-nine patients were tested twice and 49 three times within 4.2 (0.8-10.0) years. Biochemistry and clinical features at diagnosis, response to therapy, events of decompensation, and liver-related death or transplantation were evaluated.

RESULTS

Anti-HK1 and anti-KLHL2 were detected in 46.1% and 22.8% patients, respectively. AMA were positive in 93.7%, anti-sp100 in 26.4%, and anti-gp210 in 21.3% of patients. Anti-HK1 and anti-KLHL12 positivity changed over time in 13.3% and 5.5% of patients, respectively. Anti-HK1 or anti-KLHL12 were present in 37.5% of AMA-negative patients, and in 40% of AMA, anti-gp210, and anti-sp100 negative. No significant differences were observed between those with or without HK1 and KLHL12 antibodies, but transplant-free survival and time to liver decompensation were significantly lower in patients anti-HK1 positive (P = 0.039; P = 0.04) and in those anti-sp100 positive (P = 0.01; P = 0.007). No changes in survival and events of liver decompensation were observed according to the positivity of AMA, anti-KLHL12, or anti-gp210 antibodies.

DISCUSSION

HK1 and KLHL12 antibodies are present in 40% of PBC patients who are seronegative by the conventional PBC-specific antibodies. The novel antibodies remain rather steady during the course of the disease, and HK1 antibodies are associated with unfavourable outcomes.

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.

Fluctuations of antimitochondrial antibodies and anti-gp210 antibody in a patient with primary biliary cholangitis and Sjögren syndrome with subsequent autoimmune hemolytic anemia: A case report

RATIONALE

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease. It is often associated with extrahepatic autoimmune disorders. However, the concurrence of PBC and Sjögren syndrome (SS) with the subsequent onset of autoimmune hemolytic anemia (AIHA) is extremely rare.

PATIENT CONCERNS

This study investigated a 60-year-old woman admitted to our hospital with complaints of xerostomia for 5 years, pruritus for 3 years, and abnormal liver function for 3 months.

DIAGNOSES

The patient was suffering from typical clinical PBC and SS, and developed decompensated liver cirrhosis after 32 months of ursodeoxycholic acid (UDCA) therapy. In May 2018, she was readmitted to the hospital with a high fever of 39 °C, coughing, and sever fatigue without remission after 3 days of cephalosporin antibiotic therapy. During the clinical course of PBC, her antimitochondrial antibodies (AMA) titers fluctuated from 1:1000 to negative and then to weakly positive, determined by indirect immunofluorescence (IIF), immunoblotting, and enzyme-linked immunosorbent assay (ELISA) based on recombinant mitochondrial antigens; furthermore, her titers of anti-gp210, an antinuclear antibody (ANA), increased sharply. Laboratory tests and imaging were performed to diagnose PBC and SS in September 2015. However, she was subsequently diagnosed with AIHA after 32 months of UDCA therapy based on the identification of pancytopenia, increased reticulocyte (RET) count, and a positive result from the direct Coombs test.

INTERVENTIONS

UDCA, hepatic protectant, albumin infusion, chest drainage, rational antibiotic use, diuretics, and methylprednisolone were used to treat the patient.

OUTCOMES

Liver cirrhosis was complicated by the development of AIHA, which became severe at 42 months of follow-up.

LESSONS

This is the first case report showing a patient with comorbid PBC and SS, as well as the sequential development of AIHA with decreased AMA and increased anti-gp210 titers; this may have been due to immunodeficiency. These findings stress the importance of the serological screening of ANA profile, as well as repeated measurement of ANA and AMA to track PBC progression and prognosis.

Epigenetic Modifications in Generalized Autoimmune Epithelitis: Sjögren's Syndrome and Primary Biliary Cholangitis

Sjögren's syndrome (SjS) and primary biliary cholangitis (PBC) can be classified as a model of generalized autoimmune epithelitis based on their frequent coexistence in clinical practice and the highly specific immune mediated injury of target epithelial cells. Both of these autoimmune diseases are characterized by female predominance, highly specific circulating autoantibodies, and immune-mediated destruction of the salivary and lachrymal glands and the biliary epithelial cells, respectively. Although the genetic predisposition has been well described for both diseases, genetic studies have failed to completely elucidate their pathogenesis. The recent integration of epigenetic data, analyzing the different cellular partners, opens new perspectives and allows for better understanding of these complex and still incurable diseases. Epigenetic studies on SjS have elucidated the role of DNA methylation alterations in disease pathogenesis, while epigenetic changes that influence expression of genes on the X chromosome have been implicated in the geo-variability and occurrence of PBC. The aim of this review is to describe the advances in epigenetics in the field of autoimmune epithelitis as well as to highlight how epigenetic changes could contribute to better understanding of disease pathogenesis and progression. These advances could yield insights on novel therapeutic interventions.

Genome-wide Association Studies of Specific Antinuclear Autoantibody Subphenotypes in Primary Biliary Cholangitis

Anti-nuclear antibodies to speckled 100 kDa (sp100) and glycoprotein 210 (gp210) are specific serologic markers of primary biliary cholangitis (PBC) of uncertain/controversial clinical or prognostic significance. To study the genetic determinants associated with sp100 and gp210 autoantibody subphenotypes, we performed a genome-wide association analysis of 930 PBC cases based on their autoantibody status, followed by a replication study in 1,252 PBC cases. We confirmed single-nucleotide polymorphisms rs492899 (P = 3.27 × 10-22 ; odds ratio [OR], 2.90; 95% confidence interval [CI], 2.34-3.66) and rs1794280 (P = 5.78 × 10-28 ; OR, 3.89; 95% CI, 3.05-4.96) in the human major histocompatibility complex (MHC) region associated with the sp100 autoantibody. However, no genetic variant was identified as being associated with the gp210 autoantibody. To further define specific classical human leukocyte antigen (HLA) alleles or amino acids associated with the sp100 autoantibody, we imputed 922 PBC cases (211 anti-sp100-positive versus 711 negative cases) using a Han Chinese MHC reference database. Conditional analysis identified that HLA-DRβ1-Asn77/Arg74, DRβ1-Ser37, and DPβ1-Lys65 were major determinants for sp100 production. For the classical HLA alleles, the strongest association was with DRB1*03:01 (P = 1.51 × 10-9 ; OR, 2.97; 95% CI, 2.06-4.29). Regression analysis with classical HLA alleles identified DRB1*03:01, DRB1*15:01, DRB1*01, and DPB1*03:01 alleles can explain most of the HLA association with sp100 autoantibody. Conclusion: This study indicated significant genetic predisposition to the sp100 autoantibody, but not the gp210 autoantibody, subphenotype in PBC patients. Additional studies will be necessary to determine if these findings have clinical significance to PBC pathogenesis and/or therapeutics.

Variant and Specific Forms of Autoimmune Cholestatic Liver Diseases

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the main autoimmune cholestatic liver diseases. IgG4-associated sclerosing cholangitis is another distinct immune-mediated cholestatic disorder of unknown aetiology that is frequently associated with autoimmune pancreatitis or other IgG4-related diseases. Although the majority of PBC and PSC patients have a typical presentation, there are common and uncommon important variants or specific subgroups that observed in everyday routine clinical practice. In this updated review, we summarize the published data giving also our own experience on the variants and specific groups of autoimmune cholestatic liver diseases. Actually, we give in detail the underlining difficulties and the rising dilemmas concerning the diagnosis and management of these special conditions in the clinical spectrum of autoimmune cholestatic liver diseases including the IgG4-associated sclerosing cholangitis highlighting also the uncertainties and the potential new eras of the research agenda.

Detection of Autoantibodies Against Nucleoporin p62 in Sera of Patients With Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by specific autoantibodies. We evaluated the prevalence of autoantibodies against nucleoporin p62 (anti-p62) in PBC patients' sera to determine whether it can be a marker for PBC, in comparison with other immunological and biochemical parameters. We validated the performance of our in-house ELISA technique.

METHODS

Serum samples were collected from 135 PBC patients. Thirty patients with primary sclerosing cholangitis (PSC) and 30 with autoimmune hepatitis (AIH) were included as pathological controls, and 40 healthy blood donors served as healthy controls. The presence of anti-p62 was determined by an in-house ELISA using a recombinant protein. We calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV), and positive and negative likelihood ratio (LR+ and LR-) of our in-house ELISA for diagnosing PBC based on anti-p62. Findings were correlated with biochemical data and survival.

RESULTS

Anti-p62 was detected in 32 PBC patients (23.7%). Specificity and PPV of anti-p62 for PBC were 99% and 97%, respectively. The difference between proportions of anti-p62-positive patients and controls was 0.23 (95% confidence interval [CI]: 0.03-0.40; P<0.0001); LR+ and LR- were 23.7 and 0.77, respectively. The presence of anti-p62 was associated with higher levels of bilirubin and alkaline phosphatase (P<0.001). The odds ratio for survival was 2.44 (95% CI: 0.87-6.87; P=0.091).

CONCLUSIONS

Anti-p62 may be regarded as a significant serological marker of PBC.

Immunological abnormalities in patients with primary biliary cholangitis

Primary biliary cholangitis (PBC), an autoimmune liver disease occurring predominantly in women, is characterized by high titers of serum anti-mitochondrial antibodies (AMAs) and progressive intrahepatic cholestasis. The immune system plays a critical role in PBC pathogenesis and a variety of immune cell subsets have been shown to infiltrate the portal tract areas of patients with PBC. Amongst the participating immune cells, CD4 T cells are important cytokine-producing cells that foster an inflammatory microenvironment. Specifically, these cells orchestrate activation of other immune cells, including autoreactive effector CD8 T cells that cause biliary epithelial cell (BEC) injury and B cells that produce large quantities of AMAs. Meanwhile, other immune cells, including dendritic cells (DCs), natural killer (NK) cells, NKT cells, monocytes, and macrophages are also important in PBC pathogenesis. Activation of these cells initiates and perpetuates bile duct damage in PBC patients, leading to intrahepatic cholestasis, hepatic damage, liver fibrosis, and eventually cirrhosis or even liver failure. Taken together, the body of accumulated clinical and experimental evidence has enhanced our understanding of the immunopathogenesis of PBC and suggests that immunotherapy may be a promising treatment option. Herein, we summarize current knowledge regarding immunological abnormalities of PBC patients, with emphasis on underlying pathogenic mechanisms. The differential immune response which occurs over decades of disease activity suggests that different therapies may be needed at different stages of disease.

Biomarkers for primary biliary cholangitis: current perspectives

Primary biliary cholangitis (PBC) is a chronic progressive cholestatic disease characterized by destruction of small- and medium-sized intrahepatic bile ducts. It is no longer a rare disease, since many new asymptomatic cases are incidentally identified. Liver biopsy is diagnostically critical but not always feasible or practical to be performed. Many potential, noninvasive, markers have been proposed to replace liver biopsy and further provide the assessment of disease severity and ultimate prognosis. In this review, we evaluated serum biomarkers proposed for diagnosis, extent of fibrosis, disease prognosis and attempts for early prediction of treatment response. Older biochemical and immunological markers are presented along with recent reports including the role of microRNAs and promising results based on proteomics and metabolomics.

Increased cholestatic enzymes in two patients with long-term history of ulcerative colitis: consider primary biliary cholangitis not always primary sclerosing cholangitis

Several hepatobiliary disorders have been reported in ulcerative colitis (UC) patients with primary sclerosing cholangitis (PSC) being the most specific. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, rarely occurs in UC. We present two PBC cases of 67 and 71 years who suffered from long-standing UC. Both patients were asymptomatic but they had increased cholestatic enzymes and high titres of antimitochondrial antibodies (AMA)-the laboratory hallmark of PBC. After careful exclusion of other causes of cholestasis by MRI/magnetic resonance cholangiopancreatography (MRCP), virological and microbiological investigations, a diagnosis of PBC associated with UC was established. The patients started ursodeoxycholic acid (13 mg/kg/day) with complete response. During follow-up, both patients remained asymptomatic with normal blood biochemistry. Although PSC is the most common hepatobiliary manifestation among patients with UC, physicians must keep also PBC in mind in those with unexplained cholestasis and repeatedly normal MRCP. In these cases, a reliable AMA testing can help for an accurate diagnosis.

Geoepidemiology, clinical manifestations and outcome of primary biliary cholangitis in Greece

BACKGROUND & AIMS

Primary biliary cholangitis (PBC) is a disease with rising prevalence and considerable geographical variation. To describe the prevalence, spatial and time distribution, baseline characteristics, response to treatment, outcome and the validity of GLOBE score in a large cohort of Greek PBC patients as an independent validation of this score has not been done so far.

METHODS

The last 16years, 482 PBC patients (86.5% females) were evaluated and analysed retrospectively, using a prospectively collected database. Special attention was paid to the assessment of treatment response according to GLOBE score.

RESULTS

Age at initial evaluation was 56.3±13.7years. Among 432 Thessaly residents, prevalence was 582/million (non-homogeneous distribution). Nineteen districts showed a prevalence >800/million. Symptomatic disease onset could be identified in 91 patients, with a significant peak during spring (P=0.03). At diagnosis, 43.6% were asymptomatic and 16.2% cirrhotic. Male sex (P=0.02), older age (P<0.001), alcohol consumption (P<0.01) and concomitant liver disease (P<0.001) were negative prognostic factors for cirrhosis. During a median [interquartile range, range] follow-up of 5.1 (7.8, 15.7) years, 62 patients died or underwent liver transplantation. Patients with GLOBE score>0.30 had significantly worse prognosis (P<0.001) with 5-, 10-, and 15-year survival rates of 84%, 50% and 42%.

CONCLUSIONS

There is increased PBC prevalence in Thessaly with remarkable geographic clustering and seasonal variability. PBC is diagnosed at early stages although males had a more advanced disease. GLOBE score applies perfectly in Greek patients and this will likely help detecting patients that may benefit from new therapies.

Recent advances in the diagnosis and treatment of primary biliary cholangitis

Primary biliary cholangitis (PBC), formerly referred to as primary biliary cirrhosis, is an infrequent progressive intrahepatic cholestatic autoimmune illness that can evolve into hepatic fibrosis, hepatic cirrhosis, hepatic failure, and, in some cases, hepatocellular carcinoma. The disease itself is characterized by T-lymphocyte-mediated chronic non-suppurative destructive cholangitis and elevated serum levels of extremely specific anti-mitochondrial autoantibodies (AMAs). In this article, we will not only review epidemiology, risk factors, natural history, predictive scores, radiologic approaches (e.g., acoustic radiation force impulse imaging, vibration controlled transient elastography, and magnetic resonance elastography), clinical features, serological characteristics covering biochemical markers, immunoglobulins, infections markers, biomarkers, predictive fibrosis marker, specific antibodies (including AMAs such as AMA-M2), anti-nuclear autoantibodies [such as anti-multiple nuclear dot autoantibodies (anti-sp100, PML, NDP52, anti-sp140), anti-rim-like/membranous anti-nuclear autoantibodies (anti-gp210, anti-p62), anti-centromere autoantibodies, and some of the novel autoantibodies], histopathological characteristics of PBC, diagnostic advances, and anti-diastole of PBC. Furthermore, this review emphasizes the recent advances in research of PBC in terms of therapies, including ursodeoxycholic acid, budesonide, methotrexate, obeticholic acid, cyclosporine A, fibrates such as bezafibrate and fenofibrate, rituximab, mesenchymal stem cells transplant, and hepatic transplant. Currently, hepatic transplant remains the only optimal choice with acknowledged treatment efficiency for end-stage PBC patients.

The Significance of Autoantibody Changes Over Time in Primary Biliary Cirrhosis

OBJECTIVES

In primary biliary cirrhosis (PBC), the antimitochondrial antibody is a cornerstone of diagnosis, but there have been conflicting reports about the correlation of autoantibodies with disease stage and prognosis. We studied whether autoantibody levels changed over time and sought correlations with clinical outcomes in a cohort of patients with PBC.

METHODS

We tested serial serum samples from patients with PBC at a research institution for several autoantibodies. Long-term clinical follow-up data were used to calculate the slopes (change over time) for autoantibodies, platelet count, Ishak fibrosis score, biopsy copper, and number of portal areas with bile ducts. An adverse clinical outcome was defined as hepatic decompensation, development of hepatocellular carcinoma, liver transplantation, or liver-related death. We performed linear or logistic regression or Fisher exact test as appropriate, adjusting for multiple comparisons.

RESULTS

Twenty-seven patients with PBC with 145 serum samples were studied. Of the cohort, 85% was white, 81% was female, and median follow-up time was 20 years. Of the autoantibodies tested, only sp100 changed significantly over time. The sp100 slope was inversely associated with the Ishak fibrosis slope (parameter estimate, -0.05; P = .0003).

CONCLUSIONS

While changes in most autoantibodies over time do not seem to correlate with clinical outcomes in PBC, a change in the sp100 autoantibody level may have prognostic utility with respect to the development of fibrosis on liver biopsy.

Autoimmunity in 2013

The peer-reviewed publications in the field of autoimmunity published in 2013 represented a significant proportion of immunology articles and grew since the previous year to indicate that more immune-mediated phenomena may recognize an autoimmune mechanism and illustrated by osteoarthritis and atherosclerosis. As a result, our understanding of the mechanisms of autoimmunity is becoming the paradigm for translational research in which the progress in disease pathogenesis for both tolerance breakdown and inflammation perpetuation is rapidly followed by new treatment approaches and clinical management changes. The similarities across the autoimmune disease spectrum outnumber differences, particularly when treatments are compared. Indeed, the therapeutics of autoimmune diseases are based on a growing armamentarium that currently includes monoclonal antibodies and small molecules which act by targeting molecular markers or intracellular mediators with high specificity. Among the over 100 conditions considered as autoimmune, the common grounds are well illustrated by the data reported for systemic lupus erythematosus and rheumatoid arthritis or by the plethora of studies on Th17 cells and biomarkers, particularly serum autoantibodies. Further, we are particularly intrigued by studies on the genomics, epigenetics, and microRNA at different stages of disease development or on the safe and effective use of abatacept acting on the costimulation of T and B cells in rheumatoid arthritis. We are convinced that the data published in 2013 represent a promising background for future developments that will exponentially impact the work of laboratory and clinical scientists over the next years.

Low Serum Hepcidin in Patients with Autoimmune Liver Diseases

Hepcidin, a liver hormone, is important for both innate immunity and iron metabolism regulation. As dysfunction of the hepcidin pathway may contribute to liver pathology, we analysed liver hepcidin mRNA and serum hepcidin in patients with chronic liver diseases. Hepcidin mRNA levels were determined in liver biopsies obtained from 126 patients with HCV (n = 21), HBV (n = 23), autoimmune cholestatic disease (primary biliary cirrhosis and primary sclerosing cholangitis; PBC/PSC; n = 34), autoimmune hepatitis (AIH; n = 16) and non-alcoholic fatty liver disease (NAFLD; n = 32). Sera sampled on the biopsy day from the same patients were investigated for serum hepcidin levels. Hepatic hepcidin mRNA levels correlated positively with ferritin and negatively with serum γ-GT levels. However, no correlation was found between serum hepcidin and either ferritin or liver hepcidin mRNA. Both serum hepcidin and the serum hepcidin/ferritin ratio were significantly lower in AIH and PBC/PSC patients’ sera compared to HBV, HCV or NAFLD (P<0.001 for each comparison) and correlated negatively with serum ALP levels. PBC/PSC and AIH patients maintained low serum hepcidin during the course of their two-year long treatment. In summary, parallel determination of liver hepcidin mRNA and serum hepcidin in patients with chronic liver diseases shows that circulating hepcidin and its respective ratio to ferritin are significantly diminished in patients with autoimmune liver diseases. These novel findings, once confirmed by follow-up studies involving bigger size and better-matched disease subgroups, should be taken into consideration during diagnosis and treatment of autoimmune liver diseases.

The accuracy of the anti-mitochondrial antibody and the M2 subtype test for diagnosis of primary biliary cirrhosis: a meta-analysis

The aim of this study was to evaluate the diagnostic value of anti-mitochondrial antibodies (AMAs) and/or the M2 subtype (AMA-M2) in patients with primary biliary cirrhosis (PBC). AMA/AMA-M2 data were obtained by searching electronic databases. Studies showing AMA/AMA-M2 results in patients with PBC and control groups with other liver diseases or healthy livers were included. The quality of the involved studies was assessed using the QUADAS tool. The pooled sensitivity and specificity were calculated, and stratified analysis was performed according to possible heterogeneity sources. The pooled AMA (all methods) sensitivity and specificity were 84.5% (95% confidence interval (CI) 83.3%-85.6%) and 97.8% (95% CI 97.6%-98.0%), respectively. The positive and negative likelihood ratios were 25.201 (95% CI 17.583-36.118) and 0.162 (95% CI 0.131-0.199), respectively. The current evidence suggests that AMA and AMA-M2 show favorable accuracy for the diagnosis of PBC with high specificity and sensitivity. AMA is a better and more comprehensive marker than AMA-M2. The accuracy established in this meta-analysis is based on clinical studies using patient cohorts from different ethnicities.

Primary biliary cirrhosis: Pathophysiology, clinical presentation and therapy

Primary biliary cirrhosis (PBC) is an autoimmune, slowly progressive, cholestatic, liver disease characterized by a triad of chronic cholestasis, circulating anti-mitochondrial antibodies (AMA), and characteristic liver biopsy findings of nonsuppurative destructive cholangitis and interlobular bile duct destruction. About 10% of PBC patients, however, lack AMA. A variant, called PBC-autoimmune hepatitis (AIH) overlap, is characterized by the above findings of PBC together with findings of elevated serum alanine aminotransferase, elevated serum immunoglobulin G, and circulating anti-smooth muscle antibodies, with liver biopsy demonstrating periportal or periseptal, lymphocytic, piecemeal necrosis. PBC is hypothesized to be related to environmental exposure in genetically vulnerable individuals. It typically occurs in middle-aged females. Prominent clinical features include fatigue, pruritis, jaundice, xanthomas, osteoporosis, and dyslipidemia. The Mayo Risk score is the most widely used and best prognostic system. Ursodeoxycholic acid is the primary therapy. It works partly by reducing the concentration and injury from relatively toxic bile acids. PBC-AIH overlap syndrome is treated with ursodeoxycholic acid and corticosteroids, especially budesonide. Obeticholic acid and fibrate are promising new, but incompletely tested, therapies. Liver transplantation is the definitive therapy for advanced disease, with about 70% 10-year survival after transplantation. Management of pruritis includes local skin care, dermatologist referral, avoiding potential pruritogens, cholestyramine, and possibly opioid antagonists, sertraline, or rifaximin. Management of osteoporosis includes life-style modifications, administration of calcium and vitamin D, and alendronate. Statins are relatively safe to treat the osteopenia associated with PBC. Associated Sjogren’s syndrome is treated by artificial tears, cyclosporine ophthalmic emulsion to stimulate tear production; and saliva substitutes, cholinergic agents, and scrupulous oral and dental care. Complications of cirrhosis from advanced PBC include esophageal varices, ascites, spontaneous bacterial peritonitis, hepatorenal syndrome, and hepatoma formation.

Predictors of liver failure in primary biliary cirrhosis

BACKGROUND

The disease progression of patients with primary biliary cirrhosis (PBC) varies significantly, and the prognostic markers that identify those patients who will develop liver failure have been scarcely studied from a Chinese cohort. Aims. We aimed to determine the predictive factors of liver failure in patients with PBC.

METHODS

Patients who were first diagnosed as PBC with hepatic compensation between January 2007 and December 2009 were enrolled in this cohort study.

RESULTS

Altogether 398 patients were finally included. Of these patients, 80% were women, 98% had positive antimitochondrial antibodies, and 45% had positive antinuclear antibodies (ANA). To December 2012, a total of 38 patients developed liver failure. According to the outcome, patients who developed liver failure had had higher serum concentration of baseline total bilirubin (TBil) (p = 0.013) and total bile acid (TBA) (p < 0.001), and lower concentrations of baseline total cholesterol (Tch) (p = 0.008), than patients who did not develop liver failure. Additionally, the proportion of ANA positivity was statistically different between the two groups (p = 0.009). In the established model for predicting liver failure in PBC, three variables were finally selected out, including Tch (odds ratio (OR) 0.552, 95% confidence interval (CI) 0.394-0.774, p < 0.001), TBA (OR 1.006, 95% CI 1.002-1.010, p = 0.002), and ANA (+ versus -, OR 5.518, 95% CI 1.155-26.376, p = 0.032).

CONCLUSIONS

ANA, Tch, and TBA are predictors of liver failure in PBC.

Allogeneic bone marrow mesenchymal stem cell transplantation in patients with UDCA-resistant primary biliary cirrhosis

The objective of this study was to evaluate the safety and efficacy of allogeneic bone marrow mesenchymal stromal/stem cell transplantation (BM-MSCT) for patients with ursodeoxycholic acid (UDCA)-resistant primary biliary cirrhosis (PBC). Ten patients were enrolled in this trial of BM-MSCT. All patients were permitted to concurrently continue their previous UDCA treatment. The efficacy of BM-MSCT in UDCA-resistant PBC was assessed at various time points throughout the 12-month follow up. No transplantation-related side effects were observed. The life quality of the patients was improved after BM-MSCT as demonstrated by responses to the PBC-40 questionnaire. Serum levels of ALT, AST, γ-GT, and IgM significantly decreased from baseline after BM-MSCT. In addition, the percentage of CD8+ T cells was reduced, while that of CD4+CD25+Foxp3+ T cells was increased in peripheral lymphocytic subsets. Serum levels of IL-10 were also elevated. Notably, the optimal therapeutic outcome was acquired in 3 to 6 months and could be maintained for 12 months after BM-MSCT. In conclusion, allogeneic BM-MSCT in UDCA-resistant PBC is safe and appears to be effective.

The emerging role of circulating microRNAs as biomarkers in autoimmune diseases

The highly conserved RNAs known as microRNAs (miRNAs) are a class of small, single-stranded, non-coding RNAs that play a critical role in the regulation of host genome expression at the posttranscriptional level. MiRNA-mediated gene regulation is vital for normal cellular functions, such as the cell differentiation, proliferation and apoptosis, and nearly one-third of human messenger RNAs might be miRNA targets. Increasing evidence has suggested that miRNAs play a critical role in the regulating the immune system and preventing autoimmune disorders. Circulating miRNAs, which can be easily detected by a non-invasive methods, have been proven to be able to distinguish diseased individuals from healthy subjects. In addition, these circulating miRNAs have relatively high sensitivity and specificity and thus have been developed as biomarkers for the diagnosis and monitoring of human diseases. To date, nearly 100 circulating miRNAs have been proven to be biomarkers for various diseases, and this number continues to rise. This review aims to summarize the most promising identified circulating miRNAs as potential biomarkers in autoimmune diseases and to discuss current challenges and future directions in the field.

Recent advances in diagnosis and treatment of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic autoimmune liver disease characterized by the destruction of small intrahepatic bile ducts and the presence of highly specific serum antimitochondrial antibodies (AMAs). In this article, we will review the clinical, serological and histopathological features of PBC as well as the advances in the diagnosis and differential diagnosis of PBC. In addition, this article systematically describes the advances in the treatment of PBC, and the treatments include ursodeoxycholic acid (UDCA), budesonide, methotrexate (MTX), farnesoid X receptor (FXR) agonists, cyclosporine A, bezafibrate, rituximab, bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation, and liver transplantation. At present, liver transplantation is the only option with known therapeutic benefit for end-stage PBC patients.