Clinicopathological differentiation between sclerosing cholangitis with autoimmune pancreatitis and primary sclerosing cholangitis

A case of recurrent follicular cholangitis leading to decompensated cirrhosis after left-sided hepatectomy

Follicular cholangitis (FC) is a rare non-neoplastic biliary tract disease first reported in 2003. A 74-year-old woman underwent extended left hepatectomy with a diagnosis of intrahepatic cholangiocarcinoma. Histopathological examination of the surgical specimen demonstrated no malignant findings, and lymphocytic infiltration with lymphoid follicles was observed within the bile duct wall. Along with immunohistochemical findings, the patient was diagnosed with FC. More than 3 years after surgery, the patient exhibited elevated hepatobiliary enzymes and total bilirubin. Endoscopic retrograde cholangiography revealed stricture and dilation from the extrahepatic bile duct to the right intrahepatic bile duct. Histopathological findings uncovered lymphocytic infiltration without malignant results. It was concluded that bile duct stricture due to FC had newly developed in her remnant liver. Subsequently, the patient developed hypoalbuminemia, and abdominal computed tomography revealed atrophy of the remnant liver and ascites accumulation. Esophagogastroduodenoscopy exposed the development of esophageal varices, which were not observed preoperatively. The patient was diagnosed with decompensated liver cirrhosis accompanied by portal hypertension. This case strongly suggests that long-term follow-up after surgery may be required for patients with FC for screening of potential new bile duct stricture and progression to liver cirrhosis due to cholestasis.

The Clinical Utility of Soluble Serum Biomarkers in Autoimmune Pancreatitis: A Systematic Review

Autoimmune pancreatitis (AIP) is a rare etiological type of chronic pancreatitis. The clinical and radiological presentation of AIP often resembles that of pancreatic cancer. Identifying non-invasive markers for their early distinction is of utmost importance to avoid unnecessary surgery or a delay in steroid therapy. Thus, this systematic review was conducted to revisit all current evidence on the clinical utility of different serum biomarkers in diagnosing AIP, distinguishing AIP from pancreatic cancer, and predicting disease course, steroid therapy response, and relapse. A systematic review was performed for articles published up to August 2021 by searching electronic databases such as MEDLINE, Web of Science, and EMBASE. Among 5123 identified records, 92 studies were included in the qualitative synthesis. Apart from immunoglobulin (Ig) G4, which was by far the most studied biomarker, we identified autoantibodies against the following: lactoferrin, carboanhydrase II, plasminogen-binding protein, amylase-α2A, cationic (PRSS1) and anionic (PRSS2) trypsinogens, pancreatic secretory trypsin inhibitor (PSTI/SPINK1), and type IV collagen. The identified novel autoantigens were laminin 511, annexin A11, HSP-10, and prohibitin. Other biomarkers included cytokines, decreased complement levels, circulating immune complexes, N-glycan profile changes, aberrant miRNAs expression, decreased IgA and IgM levels, increased IgE levels and/or peripheral eosinophil count, and changes in apolipoprotein isoforms levels. To our knowledge, this is the first systematic review that addresses biomarkers in AIP. Evolving research has recognized numerous biomarkers that could help elucidate the pathophysiological mechanisms of AIP, bringing us closer to AIP diagnosis and its preoperative distinction from pancreatic cancer.

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.

Amendment of the Japanese consensus guidelines for autoimmune pancreatitis, 2020

In response to the latest knowledge and the amendment of the Japanese diagnostic criteria for autoimmune pancreatitis (AIP) in 2018, the Japanese consensus guidelines for managing AIP in 2013 were required to be revised. Three committees [the professional committee for developing clinical questions (CQs) and statements by Japanese specialists; the expert panelist committee for rating statements by the modified Delphi method; and the evaluating committee of moderators] were organized. Twenty specialists in AIP extracted the specific clinical statements from a total of 5218 articles (1963-2019) from a search in PubMed and the Cochrane Library. The professional committee made 14, 9, 5, and 11 CQs and statements for the current concept and diagnosis, extra-pancreatic lesions, differential diagnosis, and treatment, respectively. The expert panelists regarded the statements as valid after a two-round modified Delphi approach with individually rating these clinical statements, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. After evaluation by the moderators, the amendment of the Japanese consensus guidelines for AIP has been proposed in 2020.

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.

Histological features of autoimmune pancreatitis and IgG4-related sclerosing cholangitis with a correlation with imaging findings

Autoimmune pancreatitis (AIP) is characterized by a tumefactive inflammatory lesion resembling pancreatic carcinoma. Type 1 AIP is a pancreatic manifestation of IgG4-related disease characterized by unique histological features that can be identified on imaging. The capsule-like rim, which is a collar of hypertrophic lesion surrounding the pancreas, consists of lymphoplasmacytic infiltration and fibrosis, and storiform fibrosis is often identified. Hypertrophic lesions of various microscopic architectures such as the ducts, veins (obliterative phlebitis), arteries (periarteritis), and nerves are observed without parenchymal damage. The pancreatic lobules keep their contours, but the acinar cells are diminished and replaced by numerous inflammatory cells. These features provide clues to arrive at a diagnosis of type 1 AIP and to distinguish it from pancreatic carcinoma on imaging. In contrast, type 2 AIP is an epithelium-centered inflammation involving the ducts and lobules. Neutrophilic infiltration in the epithelium and/or lumens (granulocytic epithelial lesion) is a characteristic finding. Lobular swelling due to inflammation is the cause of pancreatic enlargement. IgG4-related sclerosing cholangitis is histologically similar to the hypertrophic ductal lesion in type 1 AIP and characterized by wall thickening due to inflammation and luminal stenosis. The epithelium is intact, which is different from bile duct carcinomas and primary sclerosing cholangitis, the latter of which is characterized by inflammation targeting the epithelium. Although the histological features of type 1 AIP and IgG4-related sclerosing cholangitis are unique, the biopsy diagnosis of these diseases has limitations, which should be recognized by clinicians.

Classification and Diagnostic Criteria for IgG4-Related Sclerosing Cholangitis

IgG4-related sclerosing cholangitis (IgG4-SC) can be classified into four types based on cholangiographic findings and regions of biliary stricture. This cholangiographic classification is useful to differentiate IgG4-SC from mimickers including cholangiocarcinoma, primary sclerosing cholangitis, and pancreatic cancer. Autoimmune pancreatitis (AIP) is a valuable clue for the diagnosis of IgG4-SC because the two are frequently found in association with each other. Two sets of diagnostic criteria for IgG4-SC have been proposed. In Japan, the clinical diagnostic criteria 2020 were recently developed. These clinical diagnostic criteria include narrowing of the intrahepatic and/or extrahepatic bile duct, thickening of the bile duct wall, serological findings, pathological findings, other organ involvement, and effectiveness of steroid therapy. When these criteria are applied, IgG4-SC is initially classified as associated or not associated with AIP, and cholangiographic classification is used for differential diagnosis. In most instances, IgG4-SC can be diagnosed on the basis of clinical diagnostic criteria. However, it is challenging to diagnose isolated IgG4-SC or IgG4-SC not associated with AIP. Here, we review the classification and diagnostic criteria for IgG4-SC, specifically focusing on the clinical diagnostic criteria 2020 and a large IgG4-SC case series from a nationwide survey in Japan.

Endoscopic retrograde cholangiopancreatography and intraductal ultrasonography in the diagnosis of autoimmune pancreatitis and IgG4-related sclerosing cholangitis

Endoscopic retrograde cholangiopancreatography is used to evaluate the narrowing of the main pancreatic duct in autoimmune pancreatitis (AIP) and biliary stricture in IgG4-related sclerosing cholangitis (IgG4-SC). Intraductal ultrasonography enables detailed visualization of the thickening of the bile duct wall in IgG4-SC. Pancreatic cancer, cholangiocarcinoma, and primary sclerosing cholangitis are important mimicking conditions of AIP and IgG4-SC. Diffuse or segmental stricture without marked upstream dilatation is a typical pancreatographic finding in AIP. By contrast, a single, short stricture with marked upstream dilatation is a typical finding in pancreatic cancer. The cholangiogram of IgG4-SC is classified into four types based on biliary stricture location, and this cholangiogram classification is useful for the differential diagnosis of IgG4-SC. Endoscopic retrograde cholangiography can be used to distinguish between IgG4-SC and primary sclerosing cholangitis. A segmental/long and intrapancreatic stricture is a characteristic finding of IgG4-SC, whereas band-like strictures, a beaded or pruned-tree appearance, and diverticulum-like outpouching are characteristic of primary sclerosing cholangitis. The characteristic intraductal ultrasonographic findings of circular-symmetrical wall thickening, smooth outer and inner margins, and homogeneous internal echo at the biliary stricture site are useful for diagnosis of IgG4-SC. Thickening of the bile duct wall at non-stricture sites is also a typical intraductal ultrasonographic finding of IgG4-SC and can be used for differential diagnosis from cholangiocarcinoma. Transpapillary bile duct and duodenal papilla biopsy during endoscopic retrograde cholangiopancreatography are also useful in the diagnosis of IgG4-SC.

Clinical diagnostic criteria for IgG4-related sclerosing cholangitis 2020: (Revision of the clinical diagnostic criteria for IgG4-related sclerosing cholangitis 2012)

Several years have passed since the clinical diagnostic criteria for IgG4-related sclerosing cholangitis 2012 were published. New findings and knowledge have accumulated since then. The Research Committees for IgG4-related Diseases and for Intractable Diseases of the Liver and Biliary Tract, in association with the Ministry of Health, Labor, and Welfare of Japan and the Japan Biliary Association, have established a working group consisting of researchers specializing in IgG4-SC and have drawn up new clinical diagnostic criteria for IgG4-SC 2020. The diagnosis of IgG4-SC is based on a combination of the following six criteria: (a) narrowing of the intra- or extrahepatic bile duct; (b) thickening of the bile duct wall; (c) serological findings; (d) pathological findings; (e) other organ involvement; and (f) effectiveness of steroid therapy. These new diagnostic criteria for IgG4-SC are useful in practice for general physicians and other non-specialists.

The long-term outcomes of patients with immunoglobulin G4-related sclerosing cholangitis: the Mayo Clinic experience

BACKGROUND

The long-term outcomes of immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) are not well known.

METHODS

The outcomes of patients with IgG4-SC at Mayo Clinic (1999-2018) were compared to an age- and gender-matched (1:1 ratio) group of patients with primary sclerosing cholangitis (PSC).

RESULTS

We identified 89 patients with IgG4-SC; median age at diagnosis was 67 years, 81% were males, and the median follow-up was 5.7 years. Seventy-eight patients received prednisone for induction of remission, and 53 received at least one other immunosuppressive agent for maintenance of remission. Of the IgG4-SC group, 10 died (median time from diagnosis until death was 6.5 years): 2 due to cirrhosis, 3 due to cholangiocarcinoma (CCA), and 5 due to non-hepatobiliary causes. Eleven patients in the PSC group underwent liver transplantation, while none did in the IgG4-SC group. The incidence of a hepatobiliary adverse event (cirrhosis or CCA) was 3.4 times greater in the PSC compared to the IgG4-SC group (events per 1000 person-years: 52.6; 95% CI 38-73; vs. 15.6; 95% CI 7-32). The probability of development of a hepatobiliary adverse event within 10 years was 11% in the IgG4-SC compared to 45% in the PSC group (P = 0.0001). The overall survival tended to be higher in the IgG4-SC compared to the PSC group (10-year: 79% vs. 68%, respectively; P = 0.11).

CONCLUSIONS

In a cohort of IgG4-SC patients, 88% of whom were treated with immunosuppressive drugs, the risk of cirrhosis and CCA was significantly lower compared to an age- and gender-matched group with PSC.

Advances in IgG4-related pancreatobiliary diseases

Autoimmune pancreatitis is an unusual form of pancreatitis that is histologically characterised by a massive infiltration of lymphocytes and IgG4-positive plasma cells and storiform fibrosis. The disease is recognised as a pancreatic manifestation of IgG4-related disease. IgG4-related sclerosing cholangitis is a biliary counterpart that is typically associated with autoimmune pancreatitis. Two parallel immunological responses are thought to underlie the pathophysiology of these diseases: a pro-inflammatory, tissue-destructive process and an anti-inflammatory feedback response, which probably relates to IgG4 production. These diseases should be differentiated from conditions with a similar presentation (eg, pancreatobiliary malignancy, primary sclerosing cholangitis) by comparison of serum IgG4 concentration, imaging features, other organ involvement, histology, and steroid responsiveness. Corticosteroids are first-line drugs, although rituximab has been shown to effectively deplete B cells in IgG4-related disease. Although the risk of relapse is high, no standardised treatment protocol exists for relapsed cases.

A Curious Case of Autoimmune Pancreatitis with IgG4-related Sclerosing Cholangitis

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is a novel entity that belongs to the immune-mediated fibroinflammatory class of IgG4-related diseases (IgG4-RD). IgG4-SC is noted to be one of the most frequent manifestations of extra-pancreatic disease among IgG4-RD, which is significantly different from primary SC (PSC) and cholangiocarcinoma (CC) as is evident in the varied approaches to treatment. IgG4-RD includes IgG4-SC and autoimmune pancreatitis (AIP).

Herein, we presented a case of IgG4-SC in a patient with obstructive jaundice secondary to AIP. We have also discussed the current recommendations for diagnostic and treatment modalities, with an emphasis on the issues that arise in obtaining a definitive classification of disease.

Atypical presentation of IgG4 sclerosing cholangitis

IgG4 sclerosing cholangitis (ISC) is a rare disease which usually presents in patients in their 60’s or above. Patients often present with obstructive jaundice as the first symptom, especially when associated with autoimmune pancreatitis. We report the case of a 20-year-old man who presented with acute abdominal pain, which was subsequently diagnosed as ISC in addition to autoimmune pancreatitis following magnetic resonance cholangiopancreatography (MRCP). The patient was thus treated with steroids.

Clinical practice guidelines for IgG4-related sclerosing cholangitis

IgG4‐related sclerosing cholangitis (IgG4‐SC) is a distinct type of cholangitis frequently associated with autoimmune pancreatitis and currently recognized as a biliary manifestation of IgG4‐related disease. Although clinical diagnostic criteria of IgG4‐SC were established in 2012, differential diagnosis from primary sclerosing cholangitis and cholangiocarcinoma is sometimes difficult. Furthermore, no practical guidelines for IgG4‐SC are available. Because the evidence level of most articles retrieved through searching the PubMed, Cochrane Library, and Igaku Chuo Zasshi databases was below C based on the systematic review evaluation system of clinical practice guidelines MINDS 2014, we developed consensus guidelines using the modified Delphi approach. Three committees (a guideline creating committee, an expert panelist committee for rating statements according to the modified Delphi method, and an evaluating committee) were organized. Eighteen clinical questions (CQs) with clinical statements were developed regarding diagnosis (14 CQs) and treatment (4 CQs). Recommendation levels for clinical statements were set using the modified Delphi approach. The guidelines explain methods for accurate diagnosis, and safe and appropriate treatment of IgG4‐SC.

Management of Autoimmune Pancreatitis

Type 1 autoimmune pancreatitis (AIP) is an IgG-4-related systemic disease that can manifest as a pancreatic disorder or another disorder of presumed autoimmune origin. Type 2 disease is typically characterized by absent IgG-4-positive cells. As patients often present with acute pancreatitis, obstructive jaundice, or pancreatic mass, it is imperative to exclude malignancy, a more common diagnosis. AIP may respond to corticosteroids, and has a strong association with other immune-mediated diseases. Recent literature suggests the benefit of immune-modulating therapy, including rituximab, although no consensus exists. This review covers the essentials of diagnosis, but focuses primarily on management of AIP.

IgG4-related sclerosing cholangitis mimicking hilar cholangiocarcinoma (Klatskin tumor): a case report of a challenging disease and review of the literature

Background

Even though IgG4-related disease has gained increased attention worldwide, the diagnosis remains challenging. IgG4-related sclerosing cholangitis (IgG4-SC) is not well described in the western hemisphere and may mimic cholangiocarcinoma (CC), especially when occurring without other symptoms such as, e.g. concurrent pancreatitis or retroperitoneal fibrosis. We present a case to add further information to the diagnosis and treatment of this challenging disease.

Case report

A 60-year-old male patient presented with painless jaundice. Prior medical history showed diabetes mellitus type I, high blood pressure, and deep vein thrombosis. Diagnostic investigations were strongly suspicious of a Klatskin tumor, although biopsies were inconclusive. The tumor marker Carbohydrate Antigen 19-9 (CA 19-9) was elevated. Prior to the recommended surgery, the patient had two second opinions in two different university hospitals, both arguing for surgery as well. The patient received hilar resection with right hemihepatectomy. During the postoperative course, some major complications occurred, i.e. recurrent pleural effusion, abscess in the liver resection area, sepsis, ileus, and restricted liver metabolism. Treatment with prednisolone did not show any improvement. Approximately 3 months after surgery, the patient died in consequence of acute respiratory failure. Histology showed no signs of CC, but IgG4-SC could be diagnosed.

Conclusion

In the case of preoperative signs of CC, differential diagnosis of IgG4-SC needs to be considered, in particular, in cases with missing histologic proof of malignant disease.

Clinical guidelines for primary sclerosing cholangitis 2017

BACKGROUND

Primary sclerosing cholangitis (PSC) is relatively rare disease and pathogenesis and methods of treatments were still not established. Then, we had conducted the making clinical guidelines to manage patients with PSC based on the literature review and expert opinions. These clinical guidelines were made for the medical doctors on the management of PSC, except child case of PSC.

METHODS

We had employed modified Delphi method. The production committee decided guidelines, strength of recommendations and evidence level after reviewed literatures systematically, and The Expert panel evaluated those. The Scientific Committee of the Japan Biliary Association (JBA) evaluated revised guidelines, and the Public comments were collected on web site of JBA.

RESULTS

We had made 16 guidelines about epidemiology/pathophysiology, diagnostics, therapy and prognosis. Also, we had made both diagnostic and therapeutic flow chart.

CONCLUSIONS

We hope that these guidelines will contribute to the improvement and development of the medical care of PSC.

Cholangitis: Diagnosis, Treatment and Prognosis

Cholangitis is a serious life-threatening situation affecting the hepatobiliary system. This review provides an update regarding the clinical and pathological features of various forms of cholangitis. A comprehensive search was performed in the PubMed, Scopus, and Web of Knowledge databases. It was found that the etiology and pathogenesis of cholangitis are heterogeneous. Cholangitis can be categorized as primary sclerosing (PSC), secondary (acute) cholangitis, and a recently characterized form, known as IgG4-associated cholangitis (IAC). Roles of genetic and acquired factors have been noted in development of various forms of cholangitis. PSC commonly follows a chronic and progressive course that may terminate in hepatobiliary neoplasms. In particular, PSC commonly has been associated with inflammatory bowel disease. Bacterial infections are known as the most common cause for AC. On the other hand, IAC has been commonly encountered along with pancreatitis. Imaging evaluation of the hepatobiliary system has emerged as a crucial tool in the management of cholangitis. Endoscopic retrograde cholangiography, magnetic resonance cholangiopancreatography and endoscopic ultrasonography comprise three of the modalities that are frequently exploited as both diagnostic and therapeutic tools. Biliary drainage procedures using these methods is necessary for controlling the progression of cholangitis. Promising results have been reported for the role of antibiotic treatment in management of AC and PSC; however, immunosuppressive drugs have also rendered clinical responses in IAC. With respect to the high rate of complications, surgical interventions in patients with cholangitis are generally restricted to those patients in whom other therapeutic approaches have failed.

Imaging of autoimmune biliary disease

Autoimmune biliary diseases are poorly understood but important to recognize. Initially, autoimmune biliary diseases are asymptomatic but may lead to progressive cholestasis with associated ductopenia, portal hypertension, cirrhosis, and eventually liver failure. The three main forms of autoimmune biliary disease are primary biliary cirrhosis, primary sclerosing cholangitis, and IgG4-associated cholangitis. Although some overlap may occur between the three main autoimmune diseases of the bile ducts, each disease typically affects a distinct demographic group and requires a disease-specific diagnostic workup. For all the autoimmune biliary diseases, imaging provides a means to monitor disease progression, assess for complications, and screen for the development of hepatobiliary malignancies that are known to affect patients with these diseases. Imaging is also useful to suggest or corroborate the diagnosis of primary sclerosing cholangitis and IgG4-associated cholangitis. We review the current literature and emphasize radiological findings and considerations for these autoimmune diseases of the bile ducts.

Reversible sclerosing cholangitis with ulcerative colitis

Sclerosing cholangitis (SC) with granulocytic epithelial lesion (GEL) responds well to immunosuppression therapy. We treated a 42-year-old Japanese female with ulcerative colitis, who was admitted for further evaluation of both an elevated alkaline phosphatase level and dilated intrahepatic bile ducts. A liver biopsy on the fourth hospital day revealed the infiltration of neutrophils into the bile duct epithelium, which was diagnosed as GEL. Because her ulcerative colitis was in an active stage, prednisolone (PSL) therapy was started. After the administration of PSL, laboratory data dramatically decreased. A liver biopsy was performed on the 66th hospital day to confirm the lesion around bile ducts in the portal tract. The infiltration of neutrophils into the bile duct epithelium disappeared after PSL administration, and IgG4-positive plasma cells were not found in the liver. Herein, we report a rare case of GEL-positive SC. The present case provides early evidence of treatment-induced histological changes as well as serial changes in biochemical data during the course of immunosuppression therapy.

IgG4-related sclerosing cholangitis: all we need to know

Our knowledge and experience of IgG4-related sclerosing cholangitis (ISC) have expanded in the last decade. ISC is one of the common organ manifestations of IgG4-related disease (IgG4-RD); approximately 60 % of patients with this systemic condition have ISC in the proximal and/or distal bile ducts. ISC needs to be discriminated from primary sclerosing cholangitis, cholangiocarcinoma, and other rare forms of lymphoplasmacytic cholangiopathy (e.g., follicular cholangitis and sclerosing cholangitis with granulocytic epithelial lesions). Its diagnosis requires a multidisciplinary approach, in which serology, histology, and imaging play crucial roles. Treatments with high-dose corticosteroids typically lead to the rapid and consistent induction of disease remission. Another promising therapeutic approach is B-cell depletion with rituximab. Although disease relapse is relatively common, provided that appropriate treatments are administered, ISC is considered a "benign" disease with a low risk of liver failure and biliary malignancy. Its molecular pathology is characterized by Th2-dominant immune reactions, regulatory T-cell activation, and CCL1-CCR8 interactions. Particular subsets of B cells such as plasmablasts and regulatory B cells also expand. A recent global proteomic study demonstrated that three significantly activated immunological cascades in ISC were all B-cell- or immunoglobulin-related (Fc-gamma receptor-mediated phagocytosis, B-cell receptor signaling pathway, and Fc-epsilon receptor I signaling pathway), suggesting the crucial roles of B cells in the underlying immune reactions. Despite the expansion of our knowledge of the pathophysiology of ISC, the exact role of IgG4 remains unclear. A better understanding of its immunopathology will offer some potential drug targets for this emerging biliary disease.

Sclerosing Cholangitis: Clinicopathologic Features, Imaging Spectrum, and Systemic Approach to Differential Diagnosis

Sclerosing cholangitis is a spectrum of chronic progressive cholestatic liver disease characterized by inflammation, fibrosis, and stricture of the bile ducts, which can be classified as primary and secondary sclerosing cholangitis. Primary sclerosing cholangitis is a chronic progressive liver disease of unknown cause. On the other hand, secondary sclerosing cholangitis has identifiable causes that include immunoglobulin G4-related sclerosing disease, recurrent pyogenic cholangitis, ischemic cholangitis, acquired immunodeficiency syndrome-related cholangitis, and eosinophilic cholangitis. In this review, we suggest a systemic approach to the differential diagnosis of sclerosing cholangitis based on the clinical and laboratory findings, as well as the typical imaging features on computed tomography and magnetic resonance (MR) imaging with MR cholangiography. Familiarity with various etiologies of sclerosing cholangitis and awareness of their typical clinical and imaging findings are essential for an accurate diagnosis and appropriate management.

Extensive Metastatic Cholangiocarcinoma Associated With IgG4-Related Sclerosing Cholangitis Misdiagnosed as Isolated IgG4-Related Sclerosing Cholangitis: A Case Report and Literature Review

As cholangiographic features of IgG4-related sclerosing cholangitis (IgG4-SC) resemble those of cholangiocarcinoma, it is highly confusing between the 2 conditions on the basis of cholangiographic findings. This study presents a case of extensive metastatic cholangiocarcinoma with IgG4-SC misdiagnosed as isolated IgG4-SC, and reviews recent studies of the 2 diseases.A 56-year-old man with no family history of malignant tumors or liver diseases presented with recurrent mild abdominal pain and distention for 3 months. Magnetic resonance cholangiopancreatography showed a 3.7 cm nodular lesion with unclear boundary in segment VI of the liver. Serum IgG4 and CA19-9 were slightly elevated. Histopathological examination was consistent with the consensus statement on the pathology of IgG4-SC. IgG4-SC was thus considered. Due to his mild symptoms, glucocorticoid was not given at first. However, 3 months after his first admission, he had more severe abdominal pain and further elevated serum CA19-9. Actually he was found suffering from extensive metastatic cholangiocarcinoma with IgG4-SC by exploratory laparotomy.The present case serves as a reminder that extensive metastatic cholangiocarcinoma with or without IgG4-SC may be misdiagnosed as an isolated IgG4-SC case if one relies solely on elevated serum and tissue IgG4 levels. We emphasize on the importance of repeated core needle biopsy or exploratory laparoscopy/laparotomy before immunosuppressive drugs are given, and on follow-up of imaging findings and serum CA19-9 once immunosuppressive therapy is started.

Biliary and hepatic involvement in IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD) is a multi-systemic disorder. IgG4-related sclerosing cholangitis (IgG4-SC) is the biliary manifestation of the disease, often in association with autoimmune pancreatitis (AIP). Hepatic manifestations of IgG4-RD are less well described within the literature.

AIM

To examine and present an overview of IgG4-RD with a focus on the biliary and hepatic manifestations.

METHODS

An electronic search using Medline was performed. Search items included 'IgG4 multi-system disease, IgG4 associated cholangitis, IgG4 associated liver disease and autoimmune pancreatitis (AIP)'.

RESULTS

IgG4-RD is characterised by an IgG4-positive lymphoplasmacytic tissue infiltrate, storiform fibrosis and an obliterative phlebitis. The HISORt criteria may be used to establish the diagnosis and incorporate a multi-disciplinary approach involving histology, radiology, serum IgG4 levels and response to steroid therapy. IgG4-SC is the commonest extrapancreatic manifestation of type-1 AIP, while the hepatic manifestations remain poorly defined. Important differential diagnoses include primary sclerosing cholangitis, secondary sclerosing cholangitis, cholangiocarcinoma and pancreatic carcinoma. Current treatment regimens remain ill defined although steroid therapy is used first line unless contraindicated. Patients with relapsing disease or multifocal disease should be considered for azathioprine. Available data would also suggest a role for rituximab.

CONCLUSIONS

IgG4-related sclerosing cholangitis is a common manifestation of IgG4-related disease which requires a multi-disciplinary approach to establish the diagnosis. Differentiating IgG4-related sclerosing cholangitis from other conditions, both benign and malignant, is challenging, but vital. Steroids remain the mainstay of treatment. Our understanding of the pathogenesis of the hepatic manifestations of IgG4-related disease continues to evolve.

Immunoglobulin G4-related pancreatic and biliary diseases

BACKGROUND

Autoimmune pancreatitis and autoimmune cholangitis are new clinical entities that are now recognized as the pancreatico-biliary manifestations of immunoglobulin (Ig) G4-related disease.

OBJECTIVE

To summarize important clinical aspects of IgG4-related pancreatic and biliary diseases, and to review the role of IgG4 in the diagnosis of autoimmune pancreatitis (AIP) and autoimmune cholangitis (AIC).

METHODS

A narrative review was performed using the PubMed database and the following keywords: "IgG4", "IgG4 related disease", "autoimmune pancreatitis", "sclerosing cholangitis" and "autoimmune cholangitis". A total of 955 articles were retrieved; of these, 381 contained relevant data regarding the IgG4 molecule, pathogenesis of IgG-related diseases, and diagnosis, management and long-term follow-up for patients with AIP and AIC. Of these 381 articles, 66 of the most pertinent were selected.

RESULTS

The selected studies demonstrated the increasing clinical importance of both AIP and AIC, which can mimic pancreatic cancer and cholangiocarcinoma, respectively. IgG4 titration in tissue or blood cannot be used alone to diagnose all IgG4-related diseases; however, it is often a useful adjunct to clinical, radiological and histological features. AIP and AIC respond to steroids; however, relapse is common and long-term maintenance treatment often required.

CONCLUSIONS

A review of the diagnosis and management of both AIC and AIP is timely and pertinent to clinical practice because the amount of information regarding these conditions has increased substantially in the past few years, resulting in significant impact on the clinical management of affected patients.

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.

Comparative MRI analysis of morphologic patterns of bile duct disease in IgG4-related systemic disease versus primary sclerosing cholangitis

OBJECTIVE

The purpose of this study was to perform a retrospective MRI-based comparative analysis of the morphologic patterns of bile duct disease in IgG4-related systemic disease (ISD, also called autoimmune pancreatitis) compared with primary sclerosing cholangitis (PSC) and the autoimmune liver diseases autoimmune hepatitis and primary biliary cirrhosis.

MATERIALS AND METHODS

This study included 162 consecutively registered patients (47 with ISD, 73 with PSC, and 42 with autoimmune liver diseases). Two abdominal radiologists retrospectively reviewed MR images in consensus. Imaging findings on the bile ducts, liver, pancreas, and other organs were analyzed to establish disease patterns.

RESULTS

ISD was associated with contiguous thickening of intrahepatic and extrahepatic bile ducts (p<0.001), pancreatic parenchymal abnormalities (p<0.001), renal abnormalities (p<0.001), and gallbladder wall thickening (p<0.03). The severity of common bile duct wall thickness was significantly different in ISD (p<0.001). The mean single wall thickness in the ISD group was 3.00 (SD, 1.47) mm, in the PSC group was 1.89 (SD, 0.73) mm, and in the autoimmune liver disease group was 1.80 (SD, 0.67) mm. PSC was associated with liver parenchymal abnormalities (p<0.001). We did not find statistical significance between the three groups in location (p=0.220) or length (p=0.703) of extrahepatic bile duct strictures, enhancement of bile duct stricture (p=0.033), upper abdominal lymphadenopathy, or retroperitoneal fibrosis. Although presence of intrahepatic bile duct stricture was statistically significant when all three groups were compared, it was not useful for differentiating ISD from PSC.

CONCLUSION

The presence of continuous as opposed to skip disease in the bile ducts, gallbladder involvement, and single-wall common bile duct thickness greater than 2.5 mm supports a diagnosis of ISD over PSC. ISD and PSC could not be differentiated on the basis of location and length of common bile duct stricture.

Inflammatory bowel disease of primary sclerosing cholangitis: A distinct entity?

This is a review of the characteristic findings of inflammatory bowel disease (IBD) associated with primary sclerosing cholangitis (PSC) and their usefulness in the diagnosis of sclerosing cholangitis. PSC is a chronic inflammatory disease characterized by idiopathic fibrous obstruction and is frequently associated with IBD. IBD-associated with PSC (PSC-IBD) shows an increased incidence of pancolitis, mild symptoms, and colorectal malignancy. Although an increased incidence of pancolitis is a characteristic finding, some cases are endoscopically diagnosed as right-sided ulcerative colitis. Pathological studies have revealed that inflammation occurs more frequently in the right colon than the left colon. The frequency of rectal sparing and backwash ileitis should be investigated in a future study based on the same definition. The cholangiographic findings of immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) are similar to those of PSC. The rare association between IBD and IgG4-SC and the unique characteristics of PSC-IBD are useful findings for distinguishing PSC from IgG4-SC.

Mechanisms of lower bile duct stricture in autoimmune pancreatitis

OBJECTIVES

We attempted to clarify the mechanism underlying lower bile duct stricture in autoimmune pancreatitis.

METHODS

Imaging and histologic finding of the bile duct were assessed for 73 patients with autoimmune pancreatitis to clarify whether IgG4-related biliary inflammation or pancreatic head swelling is associated with lower bile duct stricture.

RESULTS

Lower bile duct stricture was found in 59 (81%) patients. Pancreatic head swelling was significantly more frequent among patients with lower bile duct stricture than those patients without lower bile duct stricture (53 [90%] vs 4 [29%]; P < 0.01). Intraductal ultrasonography findings revealed lower bile duct wall thickening in 21 (95%) of the 22 patients with lower bile duct stricture, and the lower bile duct wall of the patients with pancreatic head swelling was significantly thicker than those patients without pancreatic head swelling (P = 0.028). Among the 38 patients with lower bile duct biopsies, 14 (37%) exhibited abundant IgG4-bearing plasma cell infiltration. Among the patients with lower bile duct stricture, an IgG4-related inflammation seemed to exert a dominant effect under limited conditions, including concomitant middle bile duct stricture and neither pancreatic swelling nor pancreatic duct stricture in the head region.

CONCLUSIONS

Both pancreatic head swelling and IgG4-related biliary inflammation affect lower bile duct stricture, which may be included in IgG4-related sclerosing cholangitis. Pancreatic head swelling affects IgG4-related biliary wall thickening.

Usefulness of steroid administration for diagnosis of IgG4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is one of the IgG4-related systemic sclerosing diseases and responds well to steroid therapy. A 58-year-old male was admitted with hilar bile duct stenosis revealed by computed tomography. We performed percutaneous transhepatic right portal vein embolization (PTPE) and scheduled a right hepatectomy because a hilar cholangiocarcinoma was first suspected. However, there was no cytologic evidence of malignancy and serum IgG4 was elevated. Steroid therapy was initiated after PTPE. There was no evidence of bile duct stenosis after 4 weeks. Improving diagnostic technique, IgG4-SC was diagnosed and treated with steroid therapy. In some cases, we couldn't deny the malignancy and performed unnecessary resection. We recommend that steroid administration while waiting for the liver volume to increase after PTPE is useful. The therapy aids in the diagnosis of bile duct stenosis, which has value for a hilar bile duct limit type of IgG4-SC, as in the case reported here.

Serum protein signatures differentiating autoimmune pancreatitis versus pancreatic cancer

Autoimmune pancreatitis (AIP) is defined by characteristic lymphoplasmacytic infiltrate, ductal strictures and a pancreatic enlargement or mass that can mimic pancreatic cancer (PaCa). The distinction between this benign disease and pancreatic cancer can be challenging. However, an accurate diagnosis may pre-empt the misdiagnosis of cancer, allowing the appropriate medical treatment of AIP and, consequently, decreasing the number of unnecessary pancreatic resections.

Mass spectrometry (MS) and two-dimensional differential gel electrophoresis (2D-DIGE) have been applied to analyse serum protein alterations associated with AIP and PaCa, and to identify protein signatures indicative of the diseases. Patients' sera were immunodepleted from the 20 most prominent serum proteins prior to further 2D-DIGE and image analysis. The identity of the most-discriminatory proteins detected, was performed by MS and ELISAs were applied to confirm their expression. Serum profiling data analysis with 2D-DIGE revealed 39 protein peaks able to discriminate between AIP and PaCa. Proteins were purified and further analysed by MALDI-TOF-MS. Peptide mass fingerprinting led to identification of eleven proteins. Among them apolipoprotein A-I, apolipoprotein A-II, transthyretin, and tetranectin were identified and found as 3.0-, 3.5-, 2-, and 1.6-fold decreased in PaCa sera, respectively, whereas haptoglobin and apolipoprotein E were found to be 3.8- and 1.6-fold elevated in PaCa sera. With the exception of haptoglobin the ELISA results of the identified proteins confirmed the 2D-DIGE image analysis characteristics. Integration of the identified serum proteins as AIP markers may have considerable potential to provide additional information for the diagnosis of AIP to choose the appropriate treatment.

Sclerosing cholangitis with autoimmune pancreatitis versus primary sclerosing cholangitis: comparison on endoscopic retrograde cholangiography, MR cholangiography, CT, and MRI

BACKGROUND

It is essential to differentiate sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) from primary sclerosing cholangitis (PSC) as the treatment and prognosis of the two diseases are totally different.

PURPOSE

To compare image findings of SC-AIP and PSC on endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), computed tomography (CT), and magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Two radiologists retrospectively reviewed ERC, MRC, CT, and MRI in 28 SC-AIP and 23 PSC patients in consensus. Factors evaluated included the length, location, and multiplicity of bile duct stricture, the presence of characteristic cholangiographic features of PSC on ERC and MRC, and the presence, location, thickness, and pattern of bile duct wall thickening on CT and MRI.

RESULTS

On ERC, focal stricture, multifocal and intrahepatic bile duct stricture, and beaded, pruned-tree, and diverticulum-like appearance were more frequent in PSC than in SC-AIP patients (P ≤ 0.006). On MRC, multifocal and intrahepatic bile duct stricture and pruned-tree appearance were more frequent in PSC than in SC-AIP patients (P ≤ 0.044). On CT and MRI, the bile duct wall was thicker (5.1 mm vs. 3.1 mm; P = 0.033 and 4.3 mm vs. 3.0 mm; P = 0.01, respectively) in SC-AIP than in PSC patients. PSC was more frequently associated with intrahepatic bile duct wall thickening on both CT (93% vs. 50%; P = 0.024) and MRI (100% vs. 50%; P = 0.023) than SC-AIP.

CONCLUSION

The combination of ERC or MRC with cross-sectional images, including CT and MRI, may be helpful in differentiating between SC-AIP and PSC.

IgG4-associated cholangitis

IgG4-associated cholangitis is the hepatobiliary manifestation of a recently characterized inflammatory systemic disease, associated with increased IgG4 serum levels and IgG4-positive lymphoplasmacytic infiltration. Often, patients present with obstructive jaundice, and imaging reveals stenoses of the extrahepatic or intrahepatic bile ducts, often in association with parenchymal pancreatic findings and irregularities of the pancreatic duct. The histologic findings include lymphoplasmacytic infiltrates, on occasion resulting in tumefactive lesions (which can mimic malignancy), obliterative phlebitis, and fibrotic changes. Steroid treatment is the mainstay of management, but relapse is common after discontinuation of therapy or during tapering of steroids and may require further treatment.

Clinical diagnostic criteria of IgG4-related sclerosing cholangitis 2012

BACKGROUND

IgG4-sclerosing cholangitis (IgG4-SC) patients have an increased level of serum IgG4, dense infiltration of IgG4-positive plasma cells with extensive fibrosis in the bile duct wall, and a good response to steroid therapy. However, it is not easy to distinguish IgG4-SC from primary sclerosing cholangitis, pancreatic cancer, and cholangiocarcinoma on the basis of cholangiographic findings alone because various cholangiographic features of IgG4-SC are similar to those of the above progressive or malignant diseases.

METHODS

The Research Committee of IgG4-related Diseases and the Research Committee of Intractable Diseases of Liver and Biliary Tract in association with the Ministry of Health, Labor and Welfare, Japan and the Japan Biliary Association have set up a working group consisting of researchers specializing in IgG4-SC, and established the new clinical diagnostic criteria of IgG4-SC 2012.

RESULTS

The diagnosis of IgG4-SC is based on the combination of the following 4 criteria: (1) characteristic biliary imaging findings, (2) elevation of serum IgG4 concentrations, (3) the coexistence of IgG4-related diseases except those of the biliary tract, and (4) characteristic histopathological features. Furthermore, the effectiveness of steroid therapy is an optional extra diagnostic criterion to confirm accurate diagnosis of IgG4-SC.

CONCLUSION

These diagnostic criteria for IgG4-SC are useful in practice for general physicians and other nonspecialists.

Autoimmune cholangitis and cholangiocarcinoma

Autoimmune cholangitis, immunoglobulin G4-associated cholangitis (IAC), is a part of multiorgan IgG4-related systemic disease, which was recognized as a new clinicopathological entity in recent years. IAC is defined as a biliary stricture that responds to steroid therapy, frequently is associated with other fibrosing conditions, especially autoimmune pancreatitis and is characterized by elevation of IgG4 in serum and infiltration of IgG4 positive plasma cells in bile ducts. Since IAC shares a number of clinical, biochemical, and imaging features with cholangiocarcinoma (CCA), it is often misdiagnosed as CCA, and unnecessary surgery was performed. In this compact review, we clarify the disease of IAC, summarize criteria for diagnosis of IAC, discuss the role of CA 19-9, and provide key information to differentiate diagnosis of IAC from CCA. IAC should be highly suspected in unexplained biliary stricture associated with increased IgG4 (in serum especially in bile) and other organ involvement (kidney, retroperitoneum etc. especially pancreas in which there are abundant IgG4-positive plasmocytes infiltration). Correct diagnosis of IAC will avoid unnecessary surgery because IAC responds well to steroid therapy. In a word, increased IgG4 levels, other organ involvement and response to steroids are keys to distinguishing IAC from CCA.

Immunoglobulin G4-related cholangitis: a variant of IgG4-related systemic disease

IgG4-related sclerosing cholangitis as part of IgG4 systemic-related diseases is commonly associated with autoimmune pancreatitis. Major clinical manifestations of IgG4-related sclerosing diseases are apparent in the organs in which tissue fibrosis with obstructive phlebitis is pathologically induced. IgG4-related sclerosing cholangitis is included within the heterogeneous group of 'sclerosing cholangitis'. Sclerosing cholangitis may be associated with choledocholithiasis, infection or biliary malignancies. Sclerosing cholangitis of unknown etiology is called primary sclerosing cholangitis (PSC). Conservative therapy of PSC is usually unsuccessful, the disease involves extra- and/or intrahepatic biliary tree, and the end point of this disease is liver cirrhosis. Typically, PSC is identified at the age of 30 to 40 years, and the disease is frequently associated with inflammatory bowel diseases. On the other hand, IgG4-related sclerosing cholangitis is not associated with inflammatory bowel diseases. In patients with IgG4-related sclerosing cholangitis, a first symptom can be obstructive jaundice, whereas obstructive jaundice is rarely present in PSC. Clinically, patients with IgG4-related sclerosing cholangitis are older at diagnosis compared to patients with PSC. A typical diagnostic feature of IgG4-related sclerosing cholangitis is elevation of serum immunoglobulin G4. In patients with IgG4-related sclerosing cholangitis, response to steroid therapy is high; in patients with PSC corticosteroid therapy is unsuccessful. Histochemically abundant infiltration of IgG4-positive plasma cells is detected in the biliary duct wall. Histologically, we can identify dense lymphoplasmacytic infiltration of the bile duct wall, transmural fibrosis, lymphoplasmacytic infiltration and fibrosis in the periportal area of the liver - a typically obliterative phlebitis. The biliary epithelium is usually intact in contrast to PSC, where mucosal erosion is often present. Steroids are the first-choice therapy of IgG4-related sclerosing cholangitis. In the literature, cholangiocarcinoma in patients with IgG4- related sclerosing cholangitis was not described, whereas cholangiocarcinoma develops in up to 10-30% of patients with PSC.

Evolving concepts in primary sclerosing cholangitis

Patients suffering from primary sclerosing cholangitis (PSC) show considerable differences regarding clinical manifestations (i.e. large duct versus small-duct PSC, presence or absence of concomitant inflammatory bowel disease), disease progression, risk for malignancy and response to therapy, raising the question whether PSC may represent a mixed bag of diseases of different aetiologies. The growing list of secondary causes and diseases 'mimicking' or even overlapping with PSC (e.g. IgG4-associated sclerosing cholangitis), which frequently causes problems in clear-cut discrimination from classic PSC and the emerging knowledge about potential disease modifier genes (e.g. variants of CFTR, TGR5 and MDR3) support such a conceptual view. In addition, PSC in children differs significantly from PSC in adults in several aspects resulting in distinct therapeutic concepts. From a clinical perspective, appropriate categorization and careful differential diagnosis are essential for the management of concerned patients. Therefore, the aim of the current review is to summarize current and evolving pathophysiological concepts and to provide up-to-date perspectives including future treatment strategies for PSC.

Immunoglobulin subclass 4 for the diagnosis of immunoglobulin subclass 4-associated diseases in an unselected liver and pancreas clinic population

AIMS

  The diagnosis of autoimmune pancreatitis (AIP) and immunoglobulin subclass 4 (IgG(4) )-associated cholangitis (IAC) is based on imaging studies, serology, histology and a response to steroid therapy. The major serological finding is an elevation of the serum IgG(4) concentration. Previous studies have shown that its sensitivity is about 70% and its specificity exceeds 90% at a cut-off of 140 mg/dl in selected patient populations. The aim of the present study was to assess the performance of serum IgG(4) as a diagnostic parameter in an unselected liver and pancreas clinic population.

METHODS AND RESULTS

  IgG(4) was prospectively determined in 1412 patients and clinical diagnoses were recorded from a review of patient charts. The prevalence of AIP or IAC in the entire cohort was 1.1% (n= 15). The sensitivity of IgG(4) for the diagnosis of AIP and IAC was 80% and the specificity was 86% at a cut-off value of ≥135 mg/dl. The positive predictive value and the negative predictive value were 6% and 99.7%, respectively. The most common differential diagnosis in patients with elevated IgG(4) was liver cirrhosis.

CONCLUSION

  IgG(4) has a reasonable sensitivity and specificity in a liver and pancreas clinic population, where liver cirrhosis appears to be the most frequent differential diagnosis for elevated IgG(4) concentrations.

Diagnostic criteria for IgG4-related sclerosing cholangitis based on cholangiographic classification

BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-SC) needs to be differentiated from pancreatic cancer (PCa), primary sclerosing cholangitis (PSC), and cholangiocarcinoma (CC). We attempted to establish diagnostic criteria for IgG4-SC based on cholangiographic classification by comparison with several diagnostic modalities.

METHODS

We classified 62 IgG4-SC patients into three groups on the basis of cholangiographic findings to allow differentiation from PCa, PSC, and CC: Group A IgG4-SC showed features similar to PCa (Type 1, n = 32), Group B showed similarity to PSC (Type 2, n = 15), and Group C showed similarity to CC (Type 3, 4, n = 15). Thirty-five patients with PCa, 40 with PSC, and 32 CC were enrolled as controls. We retrospectively compared the clinical, imaging, serological, and histopathological features and involvement of other organs between Group A and PCa, Group B and PSC, and Group C and CC.

RESULTS

Association with autoimmune pancreatitis (AIP) (P < 0.001) and involvements with other organs (specificity 100%) were common useful diagnostic parameters in all three IgG4-SC groups. A high serum IgG4 level was a useful parameter in Groups A and B (P < 0.001). Discriminant analysis of cholangiograms (P < 0.001), liver biopsy (specificity 100%), and exclusion of inflammatory bowel disease (specificity 100%) were useful parameters in Group B. Intraductal ultrasonography findings (P < 0.001) and exclusion of malignancy by bile duct biopsy (specificity 100%) were useful parameters in Group C. We established diagnostic criteria for IgG4-SC (sensitivity 100%, specificity 96.3%) by incorporating parameters that showed P < 0.001 or 100% specificity.

CONCLUSIONS

Diagnostic criteria for IgG4-SC based on cholangiographic classification are useful for distinguishing it from PCa, PSC, and CC.