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

[IgG4-related systemic disease: emergence of a new systemic disease? Literature review]

Hyper-IgG4 syndrome, or IgG4-related systemic disease (IgG4-RSD), has been recently characterized by the association of a focal or diffuse enlargement in one or more organs, elevated levels of serum IgG4 and histopathological findings including "storiform" fibrosis and prominent infiltration of lymphocytes and IgG4-positive plasma cells. Pancreas was the first organ involved with sclerosing pancreatitis (or autoimmune pancreatitis). Since this first description, many extrapancreatic lesions have been described, even in the absence of pancreatitis and include sialadenitis, lacrimal gland inflammation, lymphadenopathy, aortitis, sclerosing cholangitis, tubulointerstitial nephritis, retroperitoneal fibrosis or inflammatory pseudotumors. Multiorgan lesions can occur synchronously or metachronously in a same patient, usually after 50 years of age. They all share common histopathological findings. The disease often responds well to corticosteroid therapy. In this literature review on IgG4-RSD, we present historical, epidemiological and clinical characteristics, and we review the biological and histological diagnostic criteria. To date there is no international validated diagnostic criteria. Pathophysiological hypothesis and therapeutic approaches are also discussed.

Endoscopic retrograde cholangiography does not reliably distinguish IgG4-associated cholangitis from primary sclerosing cholangitis or cholangiocarcinoma

BACKGROUND & AIMS

Distinction of immunoglobulin G4-associated cholangitis (IAC) from primary sclerosing cholangitis (PSC) or cholangiocarcinoma is challenging. We aimed to assess the performance characteristics of endoscopic retrograde cholangiography (ERC) for the diagnosis of IAC.

METHODS

Seventeen physicians from centers in the United States, Japan, and the United Kingdom, unaware of clinical data, reviewed 40 preselected ERCs of patients with IAC (n = 20), PSC (n = 10), and cholangiocarcinoma (n = 10). The performance characteristics of ERC for IAC diagnosis as well as the κ statistic for intraobserver and interobserver agreement were calculated.

RESULTS

The overall specificity, sensitivity, and interobserver agreement for the diagnosis of IAC were 88%, 45%, and 0.18, respectively. Reviewer origin, specialty, or years of experience had no statistically significant effect on reporting success. The overall intraobserver agreement was fair (0.74). The operating characteristics of different ERC features for the diagnosis of IAC were poor.

CONCLUSIONS

Despite high specificity of ERC for diagnosing IAC, sensitivity is poor, suggesting that many patients with IAC may be misdiagnosed with PSC or cholangiocarcinoma. Additional diagnostic strategies are likely to be vital in distinguishing these diseases.

Diagnostic procedures for IgG4-related sclerosing cholangitis

BACKGROUND/PURPOSE

IgG4-related sclerosing cholangitis (IgG4-SC) is one of several diseases associated with autoimmune pancreatitis (AIP). However, diffuse cholangraphic abnormalities seen in association with AIP may resemble those seen in primary sclerosing cholangitis (PSC), and the presence of segmental stenosis suggests cholangiocarcinoma. IgG4-SC responds well to steroid therapy, whereas in contrast, liver transplantation is the only effective therapy for PSC, and surgical intervention is also needed for cholangiocarcinoma. The aim of this review was to establish the diagnostic procedures for IgG4-SC.

METHODS

A literature search was conducted, covering English-language articles dealing with IgG4-SC published between 1991 and March 2010. As clinical data on IgG4-SC are limited, the author also took into consideration his own clinical experience with the treatment of IgG4-SC over a period of more than 19 years.

RESULTS

When intrapancreatic stenosis is detected, pancreatic cancer should be ruled out. If multiple intrahepatic stenosis is evident, PSC should be discriminated on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining. An association with inflammatory bowel disease (IBD) is suggestive of PSC. If stenosis is demonstrated in the hepatic hilar region, cholangiocarcinoma should be discriminated by US, EUS, IDUS, and bile duct biopsy.

CONCLUSION

For diagnosis of IgG4-SC, coexistence of AIP is the most useful finding. However, the most important consideration for clinicians is to be aware of IgG4-SC when encountering patients with obstructive jaundice.

Autoimmune pancreatitis and IgG4-related sclerosing cholangitis

PURPOSE OF REVIEW

Autoimmune pancreatitis (AIP) is a peculiar type of pancreatitis with a presumed autoimmune etiology. AIP is frequently associated with stenosis of the bile duct in the form of IgG4-related sclerosing cholangitis. This article reviews recent advances in clinicopathological findings for AIP and IgG4-related sclerosing cholangitis.

RECENT FINDINGS

AIP is currently diagnosed based on characteristic radiological findings (irregular narrowing of the main pancreatic duct and enlargement of the pancreas) in combination with serological findings (elevated serum IgG4 and presence of autoantibodies) and histopathological findings (dense infiltration of IgG4-positive plasma cells and lymphocytes with fibrosis and obliterative phlebitis in the pancreas). Other clinical characteristics include preponderance toward elderly men, common initial symptoms of obstructive jaundice, and favorable response to steroid therapy. Differentiation of AIP from pancreatic cancer is crucial. As AIP is frequently associated with various sclerosing extrapancreatic lesions showing the same peculiar histological findings seen in the pancreas, AIP is currently considered to represent a pancreatic manifestation of IgG4-related sclerosing disease. Considering the age of onset, associated diseases, cholangiography, serum IgG4 levels, and steroid responsiveness, IgG4-related sclerosing cholangitis differs from primary sclerosing cholangitis.

SUMMARY

AIP and associated extrapancreatic lesions are considered to represent clinical manifestations of IgG4-related sclerosing disease.

Immunoglobulin G4-positive plasma cell infiltration in explanted livers for primary sclerosing cholangitis

AIMS

To explore whether immunoglobulin (Ig)G4-related sclerosing cholangitis (IgG4-SC) contributes to end-stage primary sclerosing cholangitis (PSC) in the United Kingdom.

METHODS AND RESULTS

This study consisted of 41 patients who underwent liver transplantation for advanced PSC. Explanted livers were examined histologically with an emphasis on IgG4-positive plasma cell infiltration. Thirty-nine cases (95%) had minimal or mild infiltration of IgG4-positive plasma cells (≤ 30 cells/high-power field). In contrast, two cases (5%) showed plasma cell IgG4-positivity in more than 100 cells/high-power field. IgG4-positive plasma cells were accumulated preferentially in a (xantho)granulomatous tissue within large bile ducts. Except for the presence of IgG4-positive plasma cells, there was no significant histological difference between IgG4-positive and negative cases. Both showed sclerosing cholangitis with bile duct erosion and xanthogranulomatous reaction more in keeping with PSC than typical IgG4-SC. Clinically, the two patients differed from typical IgG4-related disease, in that both had associated ulcerative colitis, and one of them was younger than expected for IgG4-SC (28 years old).

CONCLUSIONS

No classical IgG4-SC could be identified in patients explanted for PSC. The two cases identified with numerous IgG4-positive plasma cells suggest a superimposed immune mechanism of uncertain nature. A prospective study is needed to assess whether such cases will be steroid-sensitive.

Small bile duct involvement in IgG4-related sclerosing cholangitis: liver biopsy and cholangiography correlation

BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-SC) needs to be differentiated from primary sclerosing cholangitis (PSC). In this study, we performed a retrospective study to reveal cases in which liver needle biopsy was useful for differential diagnosis.

METHODS

Nineteen patients with IgG4-SC and 22 patients with PSC were studied. All patients underwent endoscopic retrograde cholangiography and liver needle biopsy. We defined small bile duct involvement of IgG4-SC histologically as damage to the small bile duct associated with infiltration of ≥10 IgG4+ plasma cells per high power field (HPF). Clinicopathological characteristics were compared between IgG4-SC patients with and without small bile duct involvement.

RESULTS

Small bile duct involvement was observed in 5 (26%) of the patients with IgG4-SC. Patients with small bile duct involvement showed a higher incidence of intrahepatic biliary strictures on cholangiography (80 vs. 21%, p = 0.038). Conversely, 4 of 7 (57%) patients with intrahepatic biliary strictures on cholangiography had histologically evident small duct involvement. The number of IgG4+ plasma cells was significantly correlated with the site of the most proximal stricture on cholangiograms (p = 0.021). The number of IgG4+ plasma cells per HPF was significantly higher in IgG4-SC patients with intrahepatic biliary strictures than in those with PSC (13.4 vs. 0.4 cells/HPF, p < 0.001).

CONCLUSIONS

Involvement of small bile ducts is more frequent in patients with intrahepatic biliary strictures on cholangiography, and liver needle biopsy is especially useful for these patients.

A case of sclerosing cholangitis without pancreatic involvement thought to be associated with autoimmunity

Sclerosing cholangitis (SC) is one of the lesions frequently seen in IgG4-related systemic diseases, causing biliary stricture and mimicking bile duct carcinoma and primary sclerosing cholangitis (PSC). Although it often accompanies autoimmune pancreatitis (AIP), autoimmune-related SC without a pancreatic lesion is very rare. A 79-year-old woman was referred to our institution with suspected diagnosis of bile duct carcinoma in the previous hospital. The patient was not icteric and fever free, but with an elevated level of serum biliary enzyme, which lead us to detect this disease. Clinical images including computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS) demonstrated multiple strictures at the intrahepatic bile duct and enhanced wall thickness at the upper common bile duct, however her pancreas was normal. Repeated endoscopic procedures with multiple biopsies from the biliary strictures demonstrated fibrous ductal tissues with lymph-plasma cell infiltration (>10 IgG4(+) cells/HPF). By positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET), the uptake of FDG was not remarkable in areas other than the biliary lesions. Additional laboratory tests showed elevated levels of serum IgG (2,571 mg/dL), and γ-globulin (29%), and positive autoantibodies, but normal IgG4 (53.2 mg/dL). Together with clinical images, laboratory and histological findings, we diagnosed this patient as sclerosing cholangitis which was thought to be associated with autoimmunity. After one year of follow-up without steroid therapy, idiopathic thrombocytopenic purpura (ITP) developed with an increased level of serological markers. We encountered a rare case of sclerosing cholangitis expected to be associated with autoimmunity, which showed biliary strictures mimicking bile duct carcinoma and needed careful diagnosis. Unlike the typical AIP, the current case demonstrated distinct serological findings and no other organ involvement. Further study is needed to clarify the characteristics of sclerosing cholangitis associated with autoimmunity with a large number of cases.

Differentiation between autoimmune pancreatitis and pancreatic carcinoma based on endoscopic retrograde cholangiopancreatography findings

OBJECTIVE

We have reviewed the endoscopic retrograde cholangiopancreatography (ERCP) images of patients with autoimmune pancreatitis (AIP) and pancreatic carcinoma (Pca) in an attempt to identify findings that would facilitate making a differential diagnosis between AIP and Pca.

METHODS

The study cohort consisted of 39 patients diagnosed with AIP and 62 patients diagnosed with Pca. The ERCP findings in the pancreatic duct and biliary tract were compared between the two groups.

RESULTS

The ERCP images revealed that AIP patients had a higher prevalence of narrowing of the main pancreatic duct (MPD) for ≥ 3 cm of its length and a higher prevalence for the presence of side branches in the narrowed portion of the MPD than Pca patients (p < 0.001 and p < 0.001, respectively). In contrast, the prevalence of an upstream MPD having a maximal diameter ≥ 4 cm was significantly higher in the Pca patient group (p < 0.001). The discriminant analysis identified three significant factors: (1) whether or not side branches were present; (2) total length of the narrowed portion of the MPD; (3) maximal diameter of the upstream MPD. It was impossible to differentiate Pca from AIP in the two Pca patients in whom ERCP revealed both narrowing of the MPD for > 5 cm of its length and the presence of side branches.

CONCLUSIONS

Among our patient cohort, the ERCP findings in terms of the length of the narrowed portion of the MPD, the presence of side branches, and maximal diameter of the upstream MPD enabled differential diagnosis between AIP and Pca in most of the cases. However, it must be borne in mind that some Pca patients have ERCP findings similar to those of AIP patients.

Analysis of regulatory T cells and IgG4-positive plasma cells among patients of IgG4-related sclerosing cholangitis and autoimmune liver diseases

OBJECTIVES

Patients with autoimmune pancreatitis (AIP) characteristically show elevated serum levels of immunoglobulin G4 (IgG4) and abundant infiltration of IgG4-positive plasmacytes in the involved organs. The most common involved organ showing extrapancreatic lesions is the bile duct, which exhibits sclerosing cholangitis (SC). However, the role of IgG4 in the development of IgG4-related SC (IgG4-SC) remains unclear. To clarify the role of IgG4 in IgG4-SC, we have performed an immunohistochemical analysis of the bile duct.

METHODS

Laboratory and immunohistochemical findings of liver biopsy specimens obtained from patients with IgG4-SC, primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH), and primary biliary cirrhosis (PBC) were compared. The biopsy specimens were first stained with anti-IgG1, anti-IgG4, and anti-Foxp3 (forkhead box P3) antibodies, and the ratio of IgG4-, IgG1-, and Foxp3-positive cells, respectively, to infiltrated mononuclear cells (IgG4/Mono, IgG1/Mono, Foxp3/Mono) was assessed.

RESULTS

The ratio of IgG4/IgG1-positive plasma cells was significantly higher in specimens obtained from patients with IgG4-SC than in those from patients with PSC, AIH, and PBC. The Foxp3/Mono ratio in patients with PBC was significantly higher than that in patients with IgG4-SC and PSC. In patients with IgG4-SC, the number of Foxp3-positive cells was significantly correlated with the number of IgG4-positive cells; in the other patient groups, there was no correlation.

CONCLUSIONS

The IgG4/IgG1 ratio in the liver may be a useful marker for differential diagnosis of IgG4-SC and PSC. In IgG4-SC, abundant infiltration of regulatory T cells (Tregs) may affect the switching of B cells to IgG4-producing plasmacytes, and there is a possibility that the function of Tregs is different in IgG4-SC and other liver diseases (PSC, AIH, and PBC).

Primary sclerosing cholangitis with elevated serum IgG4 levels and/or infiltration of abundant IgG4-positive plasma cells

Immunoglobin G4-related sclerosing cholangitis (IgG4-SC) is recognized as one of the systemic sclerosing diseases characterized by abundant IgG4-positive plasma cells with effective steroid therapy. On the other hand, primary sclerosing cholangitis (PSC), recognized as a sclerosing cholangitis of unknown origin without steroid efficacy, has been often clinically confused with IgG4-SC. To date, the prognosis of IgG4-SC is unclear, while the prognosis of PSC is well known to be poor. Therefore, it is clinically very important to be able to distinguish IgG4-SC from PSC. However, at the present time it still remains unclear whether PSC may sometimes be misdiagnosed as IgG4-SC or not. Herein, we report three rare cases of PSC with elevated serum IgG4 levels and/or an infiltration of abundant IgG4-positive plasma cells in the liver: a young male with ulcerative colitis (UC), and elderly female and a young female, each with elevated serum IgG4 levels. The first two patients showed infiltration of abundant IgG4-positive plasma cells in the portal area of the liver without response to steroid therapy. From our experiences, we emphasize that some patients with PSC, who do not respond to steroid therapy, show elevated serum IgG4 levels and/or infiltration of abundant IgG4-positive plasma cells, although the mechanism still remains unclear.

Autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis (AIP) is a relatively newly recognized type of pancreatitis that is characterized by diffuse or focal swelling of the pancreas due to lymphoplasmacytic infiltration and fibrosis of the pancreatic parenchyma.

MATERIAL AND METHODS

A PubMed literature search was performed using the keywords "autoimmune pancreatitis". Sometimes, bibliographies were cross-referenced and related article searches were performed once an article of interest was identified.

RESULTS

Pathologically, AIP shows narrowing of the pancreatic ducts and the intrapancreatic portion of the common bile duct. Obstructive jaundice is a common symptom at presentation, and pancreatic cancer represents an important clinical differential diagnosis. In late stages of the disease, the normal pancreatic parenchyma is often replaced by large amounts of fibrosis. Histologically, there seem to be two subtypes of the disease-one showing infiltration with IgG4-positive plasma cells but lacking granulocytic epithelial lesions (GELs), the other showing GELs but lacking strong IgG4 positivity. AIP is in at least some instances the pancreatic manifestation of a clinicopathological entity of IgG4-related systemic sclerosing disease. On the basis of pancreatic imaging, together with serological measurement of IgG4 and evaluation of other organ involvement, many AIP patients can be identified. The remaining patients require further diagnostic work-up. In these patients, pancreatic core needle biopsy and, as AIP responds to steroid treatment, also a trial with steroids, can help to differentiate AIP from pancreatic cancer. OUTLOOK AND DISCUSSION: This review presents the pathological, radiologic and laboratory findings of AIP. Moreover, the treatment and pathogenesis are discussed.

Endoscopic transpapillary intraductal ultrasonography and biopsy in the diagnosis of IgG4-related sclerosing cholangitis

PURPOSE

IgG4-related sclerosing cholangitis (IgG4-SC) is one of the diseases associated with autoimmune pancreatitis. Several cases of IgG4-SC showed no pancreas abnormalities and it was difficult to distinguish cholangiocarcinoma. We aimed to clarify the findings of transpapillary intraductal ultrasonography (IDUS) and bile duct biopsy in the patients with IgG4-SC.

METHODS

We retrospectively evaluated the findings of transpapillary IDUS and biopsy in 23 consecutive patients with IgG4-SC at Nagoya City University Hospital between 2004 and 2008. Eleven patients with cholangiocarcinoma were enrolled as a control group.

RESULTS

IDUS findings of circular-symmetric wall thickness, a smooth outer margin, a smooth inner margin and a homogeneous internal echo in the stricture were significantly higher in IgG4-SC than in cholangiocarcinoma (p < 0.01). The wall thickness in IgG4-SC in regions of non-stricture on the cholangiogram was significantly greater than that in cholangiocarcinoma (p < 0.0001). A bile duct wall thickness exceeding 0.8 mm in regions of non-stricture on the cholangiogram was highly suggestive of IgG4-SC (sensitivity 95.0%, specificity 90.9%, accuracy 93.5%). In transpapillary biopsy, lymphoplasmacytic infiltration was observed in 100% (17/17), fibrosis in 82% (14/17), and obliterative phlebitis in 0%. The abundant IgG4-positive plasma cells were observed in 18% (3/17).

CONCLUSIONS

The IDUS findings were useful for distinction of IgG4-SC from cholangiocarcinoma. Transpapillary biopsy was not useful for direct diagnosis of IgG4-SC even after IgG4 immunostaining, but it did allow distinction of IgG4-SC from cholangiocarcinoma in some cases. IDUS and transpapillary biopsy after endoscopic retrograde cholangiopancreatography can provide further information for precise diagnosis of IgG4-SC.

Autoimmune pancreatitis: a challenging diagnostic puzzle for clinicians

Autoimmune pancreatitis is a form of pancreatitis with autoimmune stigmata that may present as either focal or diffuse gland involvement. In focal forms, autoimmune pancreatitis shares demographic, clinical, biochemical and imaging features with pancreatic cancer. Since autoimmune pancreatitis is a benign disease and steroid therapy can rapidly resolve symptoms, improve radiological findings and avoid unnecessary surgery, the current clinical challenge is how to differentiate autoimmune pancreatitis from pancreatic neoplasia. Even though definitive diagnosis of the disease is difficult, several diagnostic criteria have been proposed and progress has been made in imaging studies. The management of this unique form of pancreatitis should, therefore, be handled in centres with knowledge of all aspects of the disease. This article briefly reviews clinical aspects of autoimmune pancreatitis with a focus on its diagnostic imaging and management.

IgG4+ plasma cell infiltrates in liver explants with primary sclerosing cholangitis

Sclerosing cholangitis can be primary (PSC) or secondary. One unusual cause of secondary sclerosing cholangitis is the newly recognized entity of IgG4-associated cholangitis. The prevalence and significance of IgG4 plasma cells in patients, who are clinically and radiologically classified as PSC, however, are unknown. Clinical information and histology of liver explants of 98 consecutive liver transplants performed for PSC were reviewed. IgG4 immunohistochemical stain was performed on sections from hilar areas that contained large bile ducts and corresponding cholecystectomy specimens (available in 74 cases). Serum IgG4 levels were measured in stored serum from 81 cases. Tissue IgG4 positivity (>or=10 IgG4+ plasma cells/high power field) was correlated with clinical features (age, sex, presence of inflammatory bowel disease and cholangiocarcinoma, pancreatogram, PSC duration, PSC recurrence after transplant, and number of acute rejection episodes) and histologic findings (periductal lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis) in the liver explants. Twenty-three (23%) liver explants showed periductal infiltration with IgG4+ plasma cells. Eighteen cases (22%) had elevated serum IgG4 levels, including 8 without tissue IgG4 positivity. All cases showed dense periductal fibrosis; none had storiform fibrosis or obliterative phlebitis. IgG4 positivity in the liver strongly correlated with moderate-to-marked periductal lymphoplasmacytic inflammation (P=0.002). Clinically, IgG4 positivity in tissue, but not in serum, was correlated with shorter PSC duration before transplant and higher risk of recurrence after transplant. Nearly one quarter of explanted livers that carry a clinical diagnosis of PSC contain increased IgG4+ periductal plasma cell infiltrates and positive serum IgG4 levels. However, none of the explants show histologic features diagnostic of IgG4-associated cholangitis. PSC with tissue IgG4 positivity has a more aggressive clinical course manifested by shorter time to transplant and a higher likelihood of recurrence than IgG4 negative PSC.

Japanese clinical guidelines for autoimmune pancreatitis

OBJECTIVES

As the patients with autoimmune pancreatitis (AIP) are increasing in Japan, the practical guideline for managing AIP is required to be established.

METHODS

Three committees (the professional committee for making clinical questions [CQs] and statements by Japanese specialists, the expert panelist committee for rating statements by the modified Delphi method, and the evaluating committee by moderators) were organized. Fifteen specialists for AIP extracted the specific clinical statements from a total of 871 literatures by PubMed search (approximately 1963-2008) and from a secondary database and made the CQs and statements. The expert panelists individually rated these clinical statements using a modified Delphi approach, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid.

RESULTS

The professional committee made 13, 6, 6, and 11 CQs and statements for the concept and diagnosis, extrapancreatic lesions, differential diagnosis, and treatment, respectively. The expert panelists regarded them as valid after a 2-round modified Delphi approach.

CONCLUSIONS

After evaluation by the moderators, the Japanese clinical guideline for AIP has been established. Further studies for the international guideline are needed after international consensus for diagnosis and treatment.

IgG4-associated cholangitis: a comparative histological and immunophenotypic study with primary sclerosing cholangitis on liver biopsy material

IgG4-associated cholangitis is a steroid-responsive hepatobiliary inflammatory condition associated with autoimmune pancreatitis that clinically and radiologically mimics primary sclerosing cholangitis. In this study, we conducted a morphological and immunohistochemical analysis of liver material obtained from individuals with IgG4-associated cholangitis, and compared these with well-characterized cases of primary sclerosing cholangitis. The study group consisted of 10 patients (9 biopsy and 1 hepatectomy case) with IgG4-associated cholangitis and 17 patients with primary sclerosing cholangitis (16 needle biopsy and 1 hepatectomy case). All patients with IgG4-associated cholangitis had pancreatic involvement as well, and six pancreatectomy samples revealed characteristic histopathological features of autoimmune pancreatitis. Primary sclerosing cholangitis cases were defined by the presence of a characteristic ERCP appearance. Clinical, pathological, radiological, and follow-up data were recorded for all cases. Portal and periportal inflammation was graded according to Ishak's guidelines. Immunohistochemical stains for IgG and IgG4 were performed. The cohort of patients with IgG4-associated cholangitis (mean age: 63 years) was older than individuals with primary sclerosing cholangitis (mean age: 44 years). Seven of these cases showed intrahepatic biliary strictures. IgG4-associated cholangitis liver samples showed higher portal (P=0.06) and lobular (P=0.009) inflammatory scores. Microscopic portal-based fibro-inflammatory nodules that were composed of fibroblasts, plasma cells, lymphocytes, and eosinophils were exclusively observed in five of the IgG4-associated cholangitis cases (50%). More than 10 IgG4-positive plasma cells per HPF (high power field) were observed in 6 of the IgG4-associated cholangitis cases (mean: 60, range: 0-140 per HPF), whereas all primary sclerosing cholangitis cases showed significantly lesser numbers (mean: 0.08, range: 0-1 per HPF). On a liver biopsy, the histological features of IgG4-associated cholangitis may be distinctive, and in conjunction with IgG4 immunohistochemical stain, may help distinguish this disease from primary sclerosing cholangitis.

[Autoimmune pancreatitis]

Autoimmune pancreatitis has been established as a special entity of pancreatitis. It is an enigmatic disease since it is adding an autoimmune etiology to the existing causes of pancreatitis. Morphological hallmarks of the disease are narrowing of the pancreatic duct system and the bile duct by periductal lymphoplasmocytic inflammation. This results in many cases in obstructive jaundice due to a mass-forming lesion in the pancreatic head mimicking pancreatic ductal adenocarcinoma. Therefore, patients will frequently undergo surgery. Histopathologically, the disease can be diagnosed by IgG4-positive plasma cells. Serologically, patients may present with elevated serum IgG and IgG4 levels. Other autoantibodies are also described. Association with other autoimmune manifestations in a wide range of organs is frequent. Autoimmune pancreatitis will respond to steroid treatment, which is of specific importance because pancreatic cancer is one of its clinical differential diagnoses. It is important to positively diagnose autoimmune pancreatitis, especially if the bile ducts are affected, since cholangitis may be or become a prominent problem before or after surgery.

Resected case of eosinophilic cholangiopathy presenting with secondary sclerosing cholangitis

Eosinophilic cholangiopathy is a rare condition characterized by eosinophilic infiltration of the biliary tract and causes sclerosing cholangitis. We report a patient with secondary sclerosing cholangitis with eosinophilic cholecystitis. A 46-year-old Japanese man was admitted to our hospital with jaundice. Computed tomography revealed dilatation of both the intrahepatic and extrahepatic bile ducts, diffuse thickening of the wall of the extrahepatic bile duct, and thickening of the gallbladder wall. Under the diagnosis of lower bile duct carcinoma, he underwent pylorus-preserving pancreatoduodenectomy and liver biopsy. On histopathological examination, conspicuous fibrosis was seen in the lower bile duct wall. In the gallbladder wall, marked eosinophilic infiltration was seen. Liver biopsy revealed mild portal fibrosis. He was diagnosed as definite eosinophilic cholecystitis with sclerosing cholangitis with unknown etiology. The possible etiology of sclerosing cholangitis was consequent fibrosis from previous eosinophilic infiltration in the bile duct. The clinicopathological findings of our case and a literature review indicated that eosinophilic cholangiopathy could cause a condition mimicking primary sclerosing cholangitis (PSC). Bile duct wall thickening in patients with eosinophilic cholangitis might be due to fibrosis of the bile duct wall. Eosinophilic cholangiopathy might be confused as PSC with eosinophilia.

Recognizing immunoglobulin G4 related overlap syndromes in patients with pancreatic and hepatobiliary diseases

The first description of autoimmune pancreatitis and elevated serum immunoglobulin-G4 (IgG4) in 2001 heralded further reports of several related autoimmune diseases with raised IgG4 levels. It is now recognized that a spectrum of overlap syndromes associated with increased IgG4 and biopsy evidence of IgG4-producing plasma cells, which has now been convincingly linked with cholangitis, autoimmune hepatitis, Sjögren's syndrome, nephritis and retroperitoneal fibrosis. Collectively, this disease cluster is referred to as IgG4-related systemic disease. The importance of making the correct diagnosis is underscored by the management of individuals with IgG4-related systemic disease. In the first instance, patients generally have a dramatic response to immunosuppressive therapy, whereas patients with other forms of cholangitis and pancreatitis do not. Also, surgical management of pancreatic malignancy can be avoided once the correct diagnosis of IgG4-related disease has been made. In the present review, an overview of the current information regarding the role of IgG4 and IgG4-positive cells affecting the biliary system, pancreas and liver is provided.

Marked eosinophilia as the first manifestation of sclerosing cholangitis

We encountered a 45-year-old man who presented with marked eosinophilia as the first manifestation of sclerosing cholangitis. He was found to have a liver dysfunction during a regular physical check up and thereafter consulted our hospital. The laboratory data on admission indicated an elevation of AST (96 IU/L), ALT (136 IU/L) and ALP (1,025 IU/L). Furthermore, the leukocyte count was 18,190/mm(3) and he also showed marked eosinophilia (54.5%, 9,914/mm(3)). There were no atypical findings in the eosinophils. Other diseases causing eosinophilia, including parasite infection, allergic disorders, hypereosinophilic syndromes, drug-induced eosinophilia, malignancies, etc. were all investigated and ruled out. A liver biopsy revealed marked eosinophilic infiltration in the portal area and interlobular bile duct injury. Magnetic resonance cholangiopancreatography (MRCP) demonstrated a slight dilatation of the left intrahepatic bile ducts, but no clear diagnosis could be made at that time. A follow-up liver biopsy and endoscopic retrograde cholangiopancreatography (ERCP) finally revealed a diagnosis of secondary sclerosing cholangitis due to eosinophilic cholangiopathy. According to previous Japanese reports, eosinophilia of more than 5% was reported in 39 of 142 (27.0%) primary sclerosing cholangitis (PSC) patients. Eosinophilic cholangiopathy could cause a condition mimicking PSC and it might be confused as PSC with eosinophilia. The literature contains only about 40 case reports on eosinophilic cholangiopathy, and therefore, to date little attention has been paid to this condition. We should therefore pay attention to this condition when making a differential diagnosis of either PSC or IgG4-related sclerosing cholangitis.

Autoimmune pancreatocholangitis, non-autoimmune pancreatitis and primary sclerosing cholangitis: a comparative morphological and immunological analysis

Background

Autoimmune pancreatocholangitis (AIPC) is an emerging, not completely characterized disease. Aim of this study was the comprehensive evaluation of a series of AIPC patients, who were diagnosed and treated in a European institution between January 2003 and July 2006.

Methodology/Principal Findings

Thirty-three patients with histologically confirmed AIPC were analyzed and compared to 20 patients with non-autoimmune chronic pancreatitis (CP) and 14 patients with primary sclerosing cholangitis (PSC). Clinical features and conventional histopathology were taken into account. Immunohistochemistry and real-time quantitative PCR were used for the characterization of the inflammatory infiltrate and the stromal reaction. AIPC was localized in the pancreatic head in 94% of the patients. Intra- and/or extrapancreatic biliary tract involvement was present in 64% of the cases. The number of infiltrating T-lymphocytes, macrophages and total plasma cells was significantly higher in AIPC than in CP (3-, 4- and 8-fold increase, respectively). The absolute number of IgG4-positive plasma cells was higher in AIPC than in CP and PSC (7-fold and 35-fold increase, respectively), but significance was only reached in comparison with PSC. CXCR5- and CXCL13-positive cells were almost exclusively detected in AIPC.

Conclusions/Significance

AIPC is mainly a disease of the pancreatic head with possible extension into the periphery of the gland and/or into the biliary tract/gallbladder. The morphology of AIPC, as well as the immune- and stromal reaction is characteristic and comparable between cases with and without biliary tract involvement. Immunological markers (IgG4, CXCR5, CXCL13) can be of diagnostic relevance in specific settings.

Immunoglobulin G4-associated cholangitis

PURPOSE OF REVIEW

Immunoglobulin G4-associated cholangitis is a recently identified clinical entity characterized by infiltration of immunoglobulin G4 -bearing plasma cells in bile ducts and other affected tissues. This review is focused mainly on the most recent studies published during the last 2 years that have increased our understanding of this clinical entity.

RECENT FINDINGS

Investigations concerning the immune mechanisms, liver histology in immunoglobulin G4-associated cholangitis and reports of clinical and radiological features of the condition as well as medical therapy are discussed.

SUMMARY

Immunoglobulin G4-associated cholangitis was found to be characterized by overproduction of T helper 2 cells, and regulatory cytokines (interleukin-10 and transforming growth factor-beta) were upregulated in the affected tissues. Immunoglobulin G4 immunostaining in a range of clinically involved tissues in patients with immunoglobulin G4-associated cholangitis and autoimmune pancreatitis was found to be important for diagnostic purposes, which is probably most useful in cases with normal immunoglobulin G4 levels. It has become apparent that multiple measurements of immunoglobulin G4 levels in patients with clinically suspected immunoglobulin G4-associated cholangitis are important, revealing abnormally high levels in patients with normal immunoglobulin G4 on initial testing. Most patients respond to steroids initially but disease relapse seems to be common. A significant proportion of primary sclerosing cholangitis patients have elevated immunoglobulin G4 levels.

IgG4-negative autoimmune pancreatitis with sclerosing cholangitis and colitis: possible association with primary sclerosing cholangitis?

We report a case of autoimmune pancreatitis (AIP) with cholangiography and histopathology showing features characteristic of primary sclerosing cholangitis (PSC) and colitis. A 55-year-old previously-healthy man was diagnosed with anti-nuclear antibody (ANA)-positive AIP according to the finding of serum biochemistry, abdominal US (ultrasonography), CT (computed tomography) and ERCP (endoscopic retrograde cholangiopancreatography). However, bead-like strictures of intrahepatic bile ducts were also found and liver tissue showed onion skin-like periductal fibrosis but no anti-IgG4-positive cells. In addition, colon fiberscopy showed a pancolitis similar to ulcerative colitis indicating that, in this case, there may be an association with PSC. Here, we report a rare case of IgG4-negative AIP with sclerosing cholangitis and colitis with many clinical features that support an association with PSC.