Prevalence and impact of Sjögren's syndrome in primary biliary cholangitis: a systematic review and meta-analysis

Clinical and laboratory characteristics of Sjögren's syndrome-associated autoimmune liver disease: a real-world, 10-year retrospective study

OBJECTIVES

To investigate the clinical and laboratory features of Sjögren's syndrome-associated autoimmune liver disease (SS-ALD) patients and identify potential risk and prognostic factors.

METHODS

SS patients with or without ALD, who visited Tongji Hospital between the years 2011 and 2021 and met the 2012 American College of Rheumatology (ACR) classification criteria for Sjögren's syndrome, were retrospectively enrolled. The clinical and laboratory data of the enrolled patients, including autoimmune antibodies, were collected and analyzed with principal component analysis, correlation analysis, LASSO regression, and Cox regression.

RESULTS

A total of 117 SS-ALD patients were confirmed out of 568 SS patients. Compared to SS-non-ALD patients (n = 451), SS-ALD patients exhibited more severe involvement of the hepatic and hematologic systems, albeit with less pronounced typical SS symptoms. Disease activity was higher in SS-ALD patients, as indicated by elevated ESR, CRP, and IL-6 levels, particularly in the SS-overlap subgroup. Furthermore, SS-AIH patients without AIH-specific autoantibody testing or with negative testing results had higher AST and ALT levels than those who were autoantibody-positive. Our predictive model, incorporating IgG, IgM, AST, GGT, ALT, and C4, effectively identified ALD complications in SS patients, achieving an AUC of 0.924. Additionally, a grimmer prognosis was associated with higher baseline AST and ALT levels.

CONCLUSIONS

SS-ALD patients often manifest with an insidious onset and atypical SS symptoms, yet frequently exhibit severe systemic involvement, intense inflammatory and immune responses, and a poor prognosis. To improve the clinical outcomes in SS-ALD patients, regular monitoring, early identification, and active treatment should be applied. Key Points • The study provided a detailed profile of clinical and laboratory features of SS-ALD and SS-non-ALD patients, contributing to a predictive model of ALD complications in SS patients • SS-ALD patients manifested with an insidious onset but exhibited severe systemic involvement, robust inflammatory and immune responses, and poor prognosis • SS-AIH patients without available testing for AIH-specific autoantibodies or with negative results demonstrated worse liver function, thus routine screening for autoimmune liver antibodies is recommended in SS patients • More severe baseline liver function status was associated with poorer therapeutic responses to routine medications, so early detection and timely intervention are essential for SS patients.

Rare renal proximal tubular dysfunctions in primary biliary cholangitis

INTRODUCTION

Renal involvement of primary biliary cholangitis (PBC) usually presents as distal renal tubular acidosis. Proximal tubular (PT) dysfunctions in PBC were rarely reported with unclear clinicopathological characteristics and renal prognosis.

METHODS

We identified 11 cases of PBC with PT dysfunctions (PBC-PT). Their medical document, kidney pathology, and follow-up data were retrospectively reviewed and analyzed.

RESULTS

The 11 PBC-PT patients were mainly middle-aged (57.8 ± 5.2 years) females (81.8%). Most of them were asymptomatic PBC (7, 63.6%) with a high prevalence of elevated serum immunoglobulin M (IgM, 81.8%) and G (IgG, 54.5%) levels. In the kidney, they had a mean estimated glomerular filtration rate (eGFR) level of 46.54 ± 23.03 ml/min/1.73m2, and 81.8% of them had eGFR below 60 ml/min/1.73m2. They showed different degrees of PT dysfunctions, including hyperuricosuria, hypouricemia, normoglycemic glycosuria, generalized aminoaciduria, hyperphosphaturia, and hypophosphatemia. Their kidney pathology showed tubulointerstitial nephritis with lymphoplasmacytic infiltrates, brush border defects, and proximal tubulitis. After glucocorticoids treatment, the PT dysfunctions manifesting as hypophosphatemia, hypouricemia, and renal glycosuria all recovered, and the eGFR levels were improved from 43.24 ± 19.60 ml/min/1.73m2 to 55.02 ± 21.14 ml/min/1.73m2 (p = 0.028), accompanied by significant improvements of serum IgM levels (from 5.97 ± 4.55 g/L to 2.09 ± 1.48 g/L, p = 0.019).

CONCLUSIONS

The PT dysfunctions were rare in PBC patients, and glucocorticoids treatment could benefit the improvements of eGFR and tubular functions.

Immunoglobulin G4 in primary Sjögren's syndrome and IgG4-related disease - connections and dissimilarities

Primary Sjögren's syndrome (pSS) is an autoimmune disease, with B cell hyperactivation and autoantibody production as its immunological hallmarks. Although the distinction between immunoglobulin G4-related disease (IgG4-RD) and pSS, based on the presence or absence of certain autoantibodies, seems easy to make, possibility of elevated serum IgG4 concentration and often similar organ involvement may lead to a misdiagnosis. The increased serum concentration of IgG4 in IgG4-RD is not clearly linked to the pathogenesis of IgG-RD and it has been suggested that it may constitute just an epiphenomenon. The aim of this article is to discuss the presence of IgG4 in pSS and IgG4-RD and its potential significance for these two diseases.

Causal associations between systemic lupus erythematosus and primary biliary cholangitis: A bidirectional Mendelian randomization study

Objectives

The association between systemic lupus erythematosus (SLE) and primary biliary cholangitis (PBC) has been increasingly recognized. However, the existence of causal connections between SLE and PBC has yet to be established. In this study, we aimed to investigate the bidirectional causation between SLE and PBC utilizing Mendelian randomization (MR) analysis.

Methods

We acquired summary data from Genome-wide association studies (GWAS) for SLE and PBC from the IEU Open GWAS and FinnGen database. The inverse variance weighted (IVW) was employed as the key method to ascertain the causality between SLE and PBC. Subsequently, a range of sensitivity analyses were applied. We also performed a fixed-effects model meta-analysis to combine the MR results from different databases. Moreover, multivariable MR were conducted to clarify the roles of potential confounding factors.

Results

Our univariable MR investigation provided compelling evidence supporting a causal relationship between SLE and PBC in both directions. Specifically, the IVW method demonstrated a strong casual effect of SLE on PBC (odds ratio (OR) = 1.17, 95 % confidence interval (CI) = 1.09-1.25, p < 0.001). In addition, the results of reverse MR analysis revealed that genetically predicted PBC was associated with an increased risk of SLE (OR = 1.39, 95 % CI = 1.32-1.45, p < 0.001). The sensitivity analyses indicated the absence of horizontal pleiotropy and heterogeneity. Furthermore, the causality between SLE and PBC remained significant even after adjusting for common risk factors in the multivariable MR analysis.

Conclusions

Our study provides statistical evidence of a potential causal relationship between SLE and PBC, but further research is needed to the explore of the underlying mechanisms of these disorders.

Dissecting causal relationships between primary biliary cholangitis and extrahepatic autoimmune diseases based on Mendelian randomization

As an autoimmune disease, up to 73% of patients with primary biliary cholangitis (PBC) have a combination of extrahepatic autoimmune diseases (EHAIDs); however, the causal relationship between PBC and EHAIDs is unclear. The genome-wide association analyses provided 14 GWAS data for PBC and EHAIDs, and bidirectional, two-sample MR analyses were performed to examine the relationship between PBC and EHAIDs. The analysis using MR provides a strong and meaningful estimation of the bidirectional correlation between PBC and 7 EHAIDs: rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, autoimmune hypothyroidism, inflammatory bowel disease and ulcerative colitis of its types. In addition, PBC increases the risk of autoimmune thyroid diseases such as autoimmune hyperthyroidism and Graves' disease, as well as multiple sclerosis and psoriasis. Additionally, PBC is identified as a risk factor for Crohn's disease and Celiac disease. Based on genetic evidence, there may be connections between PBC and specific EHAIDs: not all coexisting EHAIDs induce PBC, and vice versa. This underscores the significance of prioritizing PBC in clinical practice. Additionally, if any liver function abnormalities are observed during treatment or with EHAIDs, it is crucial to consider the possibility of comorbid PBC.

Extrahepatic conditions of primary biliary cholangitis: A systematic review and meta-analysis of prevalence and risk

BACKGROUND AND AIM

Many studies reported the prevalence of extrahepatic conditions (EHC) of primary biliary cholangitis (PBC), but the great heterogeneity existed across different studies. Therefore, we conducted the systematic review and meta-analyses to determine EHC prevalence and association with PBC.

METHODS

We searched PUBMED and included observational, cross-sectional and case-controlled studies. A random or fixed effects model was used to estimate the pooled prevalence and odd ratio (OR) as appropriate.

RESULTS

Of 5370 identified publications, 129 publications with 133 studies met the inclusion criteria. Sjögren's syndrome had the highest prevalence (21.4 % vs. 3 % in non-PBC individuals), followed by Raynaud's syndrome (12.3 % vs. 1 %), rheumatoid arthritis-like arthritis (5 % vs. 3 %), systemic sclerosis (3.7 % vs. 0 %) and systemic lupus erythematosus (2 % vs. 0 %). The prevalence of overall thyroid diseases (11.3 %), autoimmune thyroid diseases (9.9 %), osteoporosis (21.1 %), celiac disease (1 %) and chronic bronchitis (4.6 %) was also increased among PBC patients.

CONCLUSION

This is the first exhaustive study on the old theme about EHC of PBC. Given increased prevalence of many EHCs in PBC patients, promptly recognizing these EHCs are of great importance for timely and precise diagnosis of PBC.

Serum vitamins and homocysteine levels in autoimmune liver disease: A systematic review and meta-analysis

OBJECTIVE

Vitamins and homocysteine (Hcy) are involved in liver metabolism and related to the pathogenesis of autoimmune liver disease (AILD), but consensus is lacking. This study aims to systematically summarize relevant evidence to clarify the association of serum vitamins and Hcy levels with AILD.

METHODS

The English and Chinese literature was searched until August 29, 2023. Studies were included if they were observational studies of investigating serum vitamins and Hcy levels in patients with AILD and their healthy comparisons. Quality assessment was performed by using the Newcastle-Ottawa Scale, and a meta-analysis was conducted using ReviewManager 5.3. The protocol was registered in the international prospective register of systematic reviews (PROSPERO), with registration number CRD42023455367.

RESULTS

A total of 25 case-control studies comprising 3487 patients (1673 patients and 1814 healthy controls) were included for analysis. There were 548 autoimmune hepatitis (AIH) cases, 1106 primary biliary cholangitis (PBC) cases, and 19 primary sclerosing cholangitis (PSC) cases. We found that serum A and E were decreased in both AIH and PBC/PSC; but vitamin C was reduced only in patients with PBC, not AIH. In addition, decreased content of 25(OH)D3 was found in both AIH and PBC. However, levels of 25(OH)D did not differ between the patients and controls, and were independent of disease types and the country. Only one study that met the inclusion criteria reported vitamin B6, B9, B12, and Hcy changes, and found that vitamin B6 and B9 were significantly decreased in patients with PBC, while serum vitamin B12 and Hcy levels were significantly elevated in them. One eligible study each confirmed a reduction in plasma vitamin K1 and 1,25(OH)2D3 in patients with PBC.

CONCLUSION

Most vitamins are deficient in AILD, so appropriate vitamin supplementation should be necessary. Further studies with larger sample sizes are needed to validate these findings.

A rare coexistence of sarcoidosis with overlap syndrome and sarcoidosis with primary biliary cholangitis and Sjogren's syndrome: Two distinct case reports

Sarcoidosis and the overlap syndrome of autoimmune hepatitis and primary biliary cholangitis (PBC) share common clinical, biological, and histological features. The simultaneous occurrence of these diseases have been reported in few cases and suggests that a common pathway which may contribute to granuloma formation in both conditions. We report the cases of two female patients having an association of sarcoidosis and inflammatory liver diseases. The first case is of a 61-year-old woman had been monitored for an overlap syndrome of PBC and autoimmune hepatitis (AIH). Therefore, treatment with azathiprine has been initiated associated with ursodeoxycholic acid (UDCA). Azathioprine had to be discontinued due to digestive intolerance, specifically chronic diarrhea and abdominal pain. The patient remained clinically stable on UDCA and her liver function tests were stable for years, until she developed symptoms of progressive dyspnea without any other associated signs. Chest computed tomography (CT) revealed mediastinal enlargement, bilateral pulmonary nodules, and symmetrical adenomegalies in the mediastinum. The bronchoalveolar lavage (BAL) revealed increased cellularity, with a notable elevation in lymphocyte count (48 %) and a CD4/CD8 ratio of 4. The patient underwent mediastinoscopy; a biopsy of the right laterotracheal (4R) adenomegaly was performed. Histological examination of the lymph node showed epithelioid and giant-cell tuberculoid lymphadenitis without necrosis, compatible with sarcoidosis. Ophthalmological and cardiac assessments were normal. Plethysmography test was normal and there was no need for corticosteroid treatment; a surveillance was planned. Treatment with UDCA was pursued. The second case is of a 50-year-old woman with no medical history presented symptoms including dry eyes and mouth, inflammatory-type polyarthralgia affecting knees and wrists, bilateral Raynaud's phenomenon, right hypochondrium pain, and worsening dyspnea over six months. Liver analysis showed elevation of alkaline phosphatase (ALP) to three times upper limit of normal (ULN) and gamma-glutamyltransferase (GGT) to 5 times ULN. This cholestasis was associated with an increase in transaminase activity to 5 times ULN for over six months. Immunological tests revealed positive anti-nuclear antibodies (ANA), anti-Ro52, anti-M23E, and anti-centromere antibodies. Chest-CT showed multiple bilateral bronchiolar parenchymal micronodules mostly in the upper and posterior regions without any mediastinal adenomegaly. Bronchial endoscopy was normal, and biopsies indicated chronic inflammation. The BAL revealed increased cellularity, characterized by a high lymphocyte count (51.7 %) and a CD4/CD8 ratio of 2.8. Biopsy of minor salivary gland revealed grade 4 lymphocytic sialadenitis. Skin biopsy revealed an epithelioid granuloma without caseous necrosis. Liver biopsy performed in the presence of cytolysis and moderate hepatic insufficiency, revealed granulomatous hepatitis and cholangitis lesions along with septal fibrosis suggestive of PBC. The diagnosis of cutaneous and pulmonary sarcoidosis with PBC and Sjögren's syndrome was retained. The spirometry and diffusing capacity for carbon monoxide value were normal. Treatment involved UDCA, corticosteroids, and azathioprine, leading to clinical and biological improvement. Sarcoidosis shares some clinical manifestations with autoimmune liver diseases, primarily PBC. A hepatic granuloma with a different appearance and location can guide the diagnosis. Early diagnosis and appropriate management can avoid serious complications and improve prognosis.

Genetic link between primary biliary cholangitis and connective tissue diseases in European populations: A two-sample Mendelian randomization study

BACKGROUND

An association between primary biliary cholangitis (PBC) and connective tissue diseases (CTDs) [rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), systemic sclerosis (SSc)] has been found in observational studies. However, the direction causality is unclear. The aim of this study was to assess the causality between PBC and CTDs and to promote early screening, pre-emptive therapy, and accurate stratification.

METHODS

A two-sample Mendelian randomization (MR) analysis was performed to assess the causal relationship between PBC [Genome-Wide Association Study (GWAS) meta-analysis, 8021 cases/16498 controls], and SLE (GWAS meta-analysis, 8021 cases/16489 controls), RA(FinnGen, 6236 cases/14727 controls), SS(FinnGen, 2495 cases/365533 controls), SSc (FinnGen, 302 cases/213145 controls). Inverse variance weighting (IVW) was used as the primary analysis method, supplemented by four sensitivity analyses to assess the robustness of the results.

RESULTS

The IVW revealed that genetically predicted PBC increased the risk of SLE [odd's ratio (OR) = 1.43, 95% confidence interval (CI) 1.30-1.58, P < 0.001]), RA (OR = 1.09, 95%CI1.04-1.14, P<0.001), and SS (OR = 1.18, 95%CI1.12-1.24, P<0.001), but not that of SSc. In addition, no association was observed between CTDs as an exposure and PBC. Sensitivity analyses did not reveal horizontal pleiotropy.

CONCLUSIONS

Our study provided new genetic evidence for a causal relationship between PBC and CTDs. PBC increased the risk of SLE, RA, and SS. Our findings highlighted the importance of active screening and intervention for CTDs in patients with PBC.

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.

The Spectrum of Extraglandular Manifestations in Primary Sjögren's Syndrome

Extraglandular manifestations (EGMs) in primary Sjogren's syndrome (pSS) represent the clinical expression of the systemic involvement in this disease. EGMs are characterized by a wide heterogeneity; virtually any organ or system can be affected, with various degrees of dysfunction. The existing gaps of knowledge in this complex domain of extraglandular extension in pSS need to be overcome in order to increase the diagnostic accuracy of EGMs in pSS. The timely identification of EGMs, as early as from subclinical stages, can be facilitated using highly specific biomarkers, thus preventing decompensated disease and severe complications. To date, there is no general consensus on the diagnostic criteria for the wide range of extraglandular involvement in pSS, which associates important underdiagnosing of EGMs, subsequent undertreatment and progression to severe organ dysfunction in these patients. This review article presents the most recent basic and clinical science research conducted to investigate pathogenic mechanisms leading to EGMs in pSS patients. In addition, it presents the current diagnostic and treatment recommendations and the trends for future therapeutic strategies based on personalized treatment, as well as the latest research in the field of diagnostic and prognostic biomarkers for extraglandular involvement in pSS.

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

Background

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

Methods

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

Results

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

Conclusion

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

Selected Aspects of the Intricate Background of Immune-Related Cholangiopathies-A Critical Overview

Primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are rare immune-related cholangiopathies with still poorly explained pathogenesis. Although triggers of chronic inflammation with subsequent fibrosis that affect cholangiocytes leading to obliteration of bile ducts and conversion to liver cirrhosis are unclear, both disorders are regarded to be multifactorial. Different factors can contribute to the development of hepatocellular injury in the course of progressive cholestasis, including (1) body accumulation of bile acids and their toxicity, (2) decreased food intake and nutrient absorption, (3) gut microbiota transformation, and (4) reorganized host metabolism. Growing evidence suggests that intestinal microbiome composition not only can be altered by liver dysfunction, but in turn, it actively impacts hepatic conditions. In this review, we highlight the role of key factors such as the gut-liver axis, intestinal barrier integrity, bile acid synthesis and circulation, and microbiome composition, which seem to be strongly related to PBC and PSC outcome. Emerging treatments and future therapeutic strategies are also presented.