Primary sclerosing cholangitis associated with elevated immunoglobulin-g4: a preliminary study

The Role of Immunoglobulin G4 in Outcomes of Primary Sclerosing Cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease that is characterized by an inflammatory and fibrotic process affecting bile ducts which eventually develops into liver cirrhosis and liver failure. The aim of this study was to investigate serum IgG subclass distribution in patients with PSC and its possible association with PSC outcomes.

PATIENTS AND METHODS

We performed a retrospective analysis of 181 patients who had been diagnosed with PSC between January 1970 and December 2015 and followed at our outpatient clinic. Their demographic, immunological, and clinical characteristics were recorded and analyzed.

RESULTS

This study included 181 patients with PSC (120 males, 61 females). There was no association between IgGs and the development of autoimmune hepatitis, cirrhosis, cholangiocarcinoma, liver transplantation, inflammatory bowel disease, and colectomy. Patients with elevated IgG4 had statistically significant higher rates of cholangitis (p = 0.02) and endoscopic retrograde cholangiopancreatography (ERCP) (p = 0.009). High IgG4 values were observed in nine patients who underwent ERCP. In these nine patients, on average, IgG4 was evaluated 5 years after ERCP (min 3 days, max 11 years). Subanalysis considering only IgG4 values evaluated before ERCP showed no significant difference but remains significant if we consider IgG4 values after ERCP.

CONCLUSION

Elevated IgG4 in our study showed a possible association with higher rates of cholangitis and ERCP among patients with primary sclerosing cholangitis. It seems that IgGs may be a useful tool for the prediction of outcomes in patients with PSC. A prospective study is necessary, especially to study the trends of IgGs values during disease as well as the role of possible seroconversion.

Clinical Utility of Personalized Serum IgG Subclass Ratios for the Differentiation of IgG4-Related Sclerosing Cholangitis (IgG4-SC) from Primary Sclerosing Cholangitis (PSC) and Cholangiocarcinoma (CCA)

Background: The differential diagnosis of immunoglobulin G4-sclerosing cholangitis (IgG4-SC) from primary sclerosing cholangitis (PSC) or cholangiocarcinoma (CCA) is important. In this study, we aimed to find the best combinations of serum IgG subclasses and IgG4 levels for differentiating IgG4-SC from PSC or CCA. Methods: In total, 31 patients with IgG4-SC, 27 patients with PSC, and 40 patients with CCA were enrolled from 2003 to 2017 at a single tertiary referral center. We retrospectively assessed the IgG4, IgG4/IgG1, IgG4/(IgG1+IgG3), and (IgG4+IgG2)/(IgG1+IgG3) in each of the patients. ROC curves were established to obtain the optimal cutoff value for each parameter. McNemar’s test was used to compare the sensitivities, specificities, and accuracies of diagnostic algorithms. Results: In differentiating IgG4-SC from PSC, the accuracies of IgG4/IgG1 ≥ 0.087 and of IgG4/(IgG1+IgG3) ≥ 0.081 were significantly higher than that of IgG4 ≥ 135 mg/dL alone (78% vs. 66%, p = 0.025). Serum IgG4 ≥ 52 mg/dL showed the best accuracy for differentiation of IgG4-SC from CCA, with a sensitivity and specificity of 80% and 82%, respectively, but this was statistically not significant (p = 0.405). Conclusions: The serum IgG4/IgG1 or IgG4/(IgG1+IgG3) level may help to differentiate IgG4-SC from PSC. IgG4 alone is the most accurate serologic marker for the differentiation of IgG4-SC from CCA.

IgG4-Related Sclerosing Cholangitis: Rarely Diagnosed, but not a Rare Disease

IgG4-related sclerosing cholangitis, a biliary manifestation of an IgG4-related disease, belongs to the spectrum of sclerosing cholangiopathies which result in biliary stenosis. It presents with signs of cholestasis and during differential diagnosis it should be distinguished from cholangiocarcinoma or from other forms of sclerosing cholangitis (primary and secondary sclerosing cholangitis). Despite increasing information and recently established diagnostic criteria, IgG4-related sclerosing cholangitis remains underdiagnosed in routine clinical practice. The diagnosis is based on a combination of the clinical picture, laboratory parameters, histological findings, and a cholangiogram. Increased serum IgG4 levels are nonspecific but are indeed a part of the diagnostic criteria proposed by the Japan Biliary Association and the HISORt criteria for IgG4-SC. High serum IgG4 retains clinical utility depending on the magnitude of elevation. Approximately 90% of patients have concomitant autoimmune pancreatitis, while 10% present with isolated biliary involvement only. About 26% of patients have other organ involvement, such as IgG4-related dacryoadenitis/sialadenitis, IgG4-related retroperitoneal fibrosis, or IgG4-related renal lesions. A full-blown histological finding characterized by IgG4-enriched lymphoplasmacytic infiltrates, obliterative phlebitis, and storiform fibrosis is difficult to capture in practice because of its subepithelial localization. However, the histological yield is increased by immunohistochemistry, with evidence of IgG4-positive plasma cells. Based on a cholangiogram, IgG-4 related sclerosing cholangitis is classified into four subtypes according to the localization of stenoses. The first-line treatment is corticosteroids. The aim of the initial treatment is to induce clinical and laboratory remission and cholangiogram normalization. Even though 30% of patients have a recurrent course, in the literature data, there is no consensus on chronic immunosuppressive maintenance therapy. The disease has a good prognosis when diagnosed early.

Review of primary sclerosing cholangitis with increased IgG4 levels

Primary sclerosing cholangitis (PSC) is a chronic progressive liver disease. Sub-types of PSC have been described, most recently PSC with elevated serum and/or tissue IgG4 subclass. We aim to summarise the clinical phenotype, disease associations, differential diagnosis, response to therapy and pathogenic mechanisms underlying PSC-high IgG4 subtype. We reviewed PubMed, MEDLINE and Embase with the search terms "primary sclerosing cholangitis", "IgG4", and "IgG4-related sclerosing cholangitis (IgG4-SC)". Elevated serum IgG4 are found in up-to one-quarter, and abundant IgG4-plasma cell infiltrates in the liver and bile ducts are found in up-to one-fifth of PSC patients. This group have a distinct clinical phenotype, with some studies reporting a more aggressive course of liver and associated inflammatory bowel disease, compared to PSC-normal IgG4 and the disease mimic IgG4-SC. Distinguishing PSC-high IgG4 from IgG4-SC remains challenging, requiring careful assessment of clinical features, organ involvement and tissue morphology. Calculation of serum IgG4:IgG1 ratios and use of a novel IgG4:IgG RNA ratio have been reported to have excellent specificity to distinguish IgG4-SC and PSC-high IgG4 but require validation in larger cohorts. A role for corticosteroid therapy in PSC-high IgG4 remains unanswered, with concerns of increased toxicity and lack of outcome data. The immunological drivers underlying prominent IgG4 antibodies in PSC are incompletely defined. An association with PSC-high IgG4 and HLA class-II haplotypes (B*07, DRB1*15), T-helper2 and T-regulatory cytokines (IL4, IL10, IL13) and chemokines (CCL1, CCR8) have been described. PSC-high IgG4 have a distinct clinical phenotype and need careful discrimination from IgG4-SC, although response to immunosuppressive treatments and long-term outcome remains unresolved. The presence of IgG4 likely represents chronic activation to persistent antigenic exposure in genetically predisposed individuals.

IgG4 subclass and gamma-glutamyl transferase in children with ulcerative colitis with primary sclerosing cholangitis and without sclerosing cholangitis

Aim of the study

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease which could be associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). The aim of this study was to compare GGT and IgG4 levels among children with UC with PSC and without PSC.

Material and methods

In this cross sectional study children with UC with PSC and UC without PSC were included. Serum immunoglobulin G4 (IgG4) and gamma-glutamyl transpeptidase (GGT) levels of the 90 UC patients with and without concomitant PSC were measured. Children with serum IgG4 concentration > 175 mg/dl were considered to have elevated IgG4.

Results

Elevated serum IgG4 was found in 8 of 30 (26.6%) patients with PSC vs. 3 of 60 (5.0%) patients without PSC. Compared with the group without symptoms of PSC, the group with PSC showed significantly higher levels of aspartate aminotransferases (AST; 22.5 U/l vs. 70.0 U/l, p < 0.001), alkaline phosphatase (ALP; 359.0 U/l vs. 602.0 U/l, p < 0.001), and IgG4 (56.0 vs. 73.0, p = 0.02). The odd ratio of the elevated IgG4 and GGT in predicting PSC was 6.9 (95% CI: 1.6-28.4) and 18 (95% CI: 5.7-55.9), respectively.

Conclusions

AST, alanine aminotransferase (ALT), GGT, ALP, and serum IgG4 were significantly higher in UC patients with sclerosing cholangitis (SC) compared to UC patients without SC. GGT and IgG-4 measurements are recommended for evaluation of UC.

Development of a scoring system for differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis

BACKGROUND

Recent research has shown that a substantial number of patients with primary sclerosing cholangitis (PSC) can also have elevated serum/tissue IgG4. The aim of our study was to develop a simple scoring system for the discrimination of IgG4-related sclerosing cholangits (IgG4-SC) from PSC.

METHODS

Patients with IgG4-SC (n = 39) and PSC (n = 76) who had intrahepatic/hilar strictures were included. Candidate-differentiating variables included patient age, other organ involvement (OOI), inflammatory bowel disease, serum IgG4, and cholangiographic features. A scoring system was developed on the basis of these variables, and its performance was internally validated using a bootstrapping-based method.

RESULTS

The scoring system in the final model included age (<30 years, 0 points; 30-39 years, 1 point; 40-49 years, 2 points; 50-59 years, 3 points; ≥60 years, 4 points), OOI (no, 0 points; yes, 3 points), and beaded appearance (yes, 0 points; no, 2 points). The patients were classified according to their total score into three categories: 0-4 points, probable PSC; 5-6 points, indicating diagnostic steroid trial; 7-9 points, probable IgG4-SC. The discrimination between IgG4-SC and PSC using the scoring system was excellent (area under the receiver operating characteristic curve, 0.986).

CONCLUSIONS

A reliable differentiation of IgG4-SC from PSC can be made using the scoring system presented here. We suggest the diagnosis of IgG4-SC at a cutoff of 7 points or higher and the indication of diagnostic steroid trial at 5 or 6 points. External validation of our scoring system is warranted.

Primary Sclerosing Cholangitis: Multiple Phenotypes, Multiple Approaches

Primary sclerosing cholangitis (PSC) is a heterogeneous, idiopathic, inflammatory disorder frequently associated with inflammatory bowel diseases. PSC patients may be classified into several subphenotypes. Investigations of pediatric, nonwhite, and female PSC patients have revealed distinguishing features. The natural history of PSC is variable in progression with numerous possible clinical outcomes. PSC patients may suffer bacterial cholangitis, cholangiocarcinoma, or colorectal adenocarcinoma. Treatments focusing on bile acid therapy and immunosuppression have not proven beneficial. Interest in PSC and international collaboration has led to improved understanding of the heterogeneity and the genetic structure and introduced possible effective therapeutics.

Primary sclerosing cholangitis: a clinical update

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a progressive cholestatic disorder that ultimately can lead to cirrhosis, liver failure, malignancy and death. It is strongly associated with inflammatory bowel disease (IBD), and though a rare disease, its incidence is increasing. There are no proven medical therapies for PSC.

SOURCES OF DATA

Ovid Medline was utilised to search for articles with keywords 'sclerosing cholangitis' and 'cholangiocarcinoma' and containing titles 'primary sclerosing cholangitis', and references of these papers were cross-referenced for further relevant manuscripts.

AREAS OF AGREEMENT

PSC is a rare disease, and there is a strong association with risk loci within the major histocompatibility complex and other genes common to other autoimmune diseases. PSC is a premalignant condition, associated with higher rates of hepatobiliary and colorectal cancer in patients with ulcerative colitis (UC).

AREAS OF CONTROVERSY

The pathogenesis is unclear, and competing theories exist surrounding toxic bile acids, enhanced homing of particular T cells from the gut to the liver and increased passage of toxins to the liver through a permeable bowel wall. It is unclear whether the higher rate of colonic cancer in PSC/UC occurs in PSC/Crohn's disease. Ursodeoxycholic acid therapy reduces liver enzymes but has not been shown to improve survival. It may reduce the prevalence of bowel cancer.

GROWING POINTS

Recent genetic studies have revealed new risk loci, pointing to the importance of the immune system and its interaction with the biome.

AREAS TIMELY FOR DEVELOPING RESEARCH

On the basis of the genetic studies discussed earlier, novel agents are being developed and trialled in the treatment of PSC.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease caused by diffuse inflammation and fibrosis that can involve the entire biliary tree. It is a progressive disorder which can ultimately lead to biliary cirrhosis, portal hypertension and hepatic failure. PSC is a complex genetic disorder with male predominance. Environmental predisposing factors include non-smoking. It is closely associated with inflammatory bowel disease (IBD), particularly ulcerative colitis, which occurs in about two thirds of PSC cases. Recent studies have suggested that PSC-IBD is a separate disease entity from IBD alone with distinctive genetic and phenotypic characteristics. Most PSC patients are asymptomatic at presentation; clinical symptoms include fatigue, jaundice, weight loss, right upper quadrant pain and pruritis. Serum biochemical tests indicate cholestasis, and diagnosis is usually established by cholangiography. In symptomatic patients, median survival from presentation to death or liver transplantation is about 12 years. It is a premalignant condition, and the majority of deaths are from malignancy, particularly cholangiocarcinoma or colonic cancer. PSC has no curative treatment. Medical treatment with ursodeoxycholic acid may slow progression of the disease and reduce colonic dysplasia, though trials lack statistical significance. Liver transplantation is the only option in young patients with PSC and advanced liver disease.

Serum immunoglobulin G4 and immunoglobulin G1 for distinguishing immunoglobulin G4-associated cholangitis from primary sclerosing cholangitis

The recent addition of immunoglobulin (Ig)G4-associated cholangitis (IAC), also called IgG4-related sclerosing cholangitis (IRSC), to the spectrum of chronic cholangiopathies has created the clinical need for reliable methods to discriminate between IAC and the more common cholestatic entities, primary (PSC) and secondary sclerosing cholangitis. The current American Association for the Study of Liver Diseases practice guidelines for PSC advise on the measurement of specific Ig (sIg)G4 in PSC patients, but interpretation of elevated sIgG4 levels remains unclear. We aimed to provide an algorithm to distinguish IAC from PSC using sIgG analyses. We measured total IgG and IgG subclasses in serum samples of IAC (n = 73) and PSC (n = 310) patients, as well as in serum samples of disease controls (primary biliary cirrhosis; n = 22). sIgG4 levels were elevated above the upper limit of normal (ULN = >1.4 g/L) in 45 PSC patients (15%; 95% confidence interval [CI]: 11-19). The highest specificity and positive predictive value (PPV; 100%) for IAC were reached when applying the 4 × ULN (sIgG4 > 5.6 g/L) cutoff with a sensitivity of 42% (95% CI: 31-55). However, in patients with a sIgG4 between 1 × and 2 × ULN (n = 38/45), the PPV of sIgG4 for IAC was only 28%. In this subgroup, the sIgG4/sIgG1 ratio cutoff of 0.24 yielded a sensitivity of 80% (95% CI: 51-95), a specificity of 74% (95% CI: 57-86), a PPV of 55% (95% CI: 33-75), and a negative predictive value of 90% (95% CI: 73-97).

CONCLUSION

Elevated sIgG4 (>1.4 g/L) occurred in 15% of patients with PSC. In patients with a sIgG4 >1.4 and <2.8 g/L, incorporating the IgG4/IgG1 ratio with a cutoff at 0.24 in the diagnostic algorithm significantly improved PPV and specificity. We propose a new diagnostic algorithm based on IgG4/IgG1 ratio that may be used in clinical practice to distinguish PSC from IAC.