IgG4-related sclerosing cholangitis: all we need to know

IgG4-related autoimmune liver disease

The term IgG4-related autoimmune liver disease (AILD) refers to hepato-biliary manifestations of Immunoglobin G4-related disease (IgG4-RD) including IgG4-related sclerosing cholangitis and IgG4-related pseudotumor. The association of some forms of autoimmune hepatitis to IgG4-RD remains controversial. Although autoimmune phenomena have not been clearly observed in IgG4-AILD, perturbation of the adaptive immune system and activation of the humoral response represent established pathophysiological hallmarks and potential therapeutic targets. Clinical manifestations of IgG4-AILD are virtually indistinguishable from bile duct cancer or primary sclerosing cholangitis and are due to mass forming lesions and thickening of the biliary tract that progressively lead to biliary ducts obstruction. There are no current reliable biomarkers for IgG4-AILD and diagnosis should rely on the integration of clinical, serological, radiological, and histological findings. In analogy to most IgG4-RD manifestations, and in contrast to its major mimickers, IgG4-AILD promptly responds to glucocorticoids but frequently relapses, thus requiring long-term maintenance therapy to avoid progressive fibrosclerotic disease and liver cirrhosis. Accumulating evidence on the efficacy of B-cell depletion therapy in patients with systemic IgG4-RD is gradually changing the treatment paradigm of IgG4-AILD and biologics will be increasingly used also for gastroenterological manifestations of IgG4-RD to spare glucocorticoids and traditional immunosuppressive agents. Looking ahead, identification of reliable biomarkers and of mini-invasive strategies to obtain informative biopsies from the biliary tree represent unavoidable priorities to optimize diagnosis and management of IgG4-AILD.

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.

Isolated mass-forming IgG4-related sclerosing cholangitis masquerading as extrahepatic cholangiocarcinoma: A case report

BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-RSC) is an uncommon benign disease, and its rarer, isolated and mass-forming subtype poses a significant challenge to differential diagnosis from cholangiocarcinoma of the extrahepatic bile duct. We herein report a case of isolated IgG4-RSC with an obstructing bile duct mass, for which extrahepatic bile duct resection was performed under the impression of proximal common bile duct (CBD) cancer.

CASE SUMMARY

A 79-year-old male was admitted for jaundice that had developed 1 mo prior. There was no family history for autoimmune diseases or biliary cancer. Computed tomography (CT) and magnetic resonance cholangiopancreaticography revealed a short segmental concentric wall thickening of the proximal CBD with diffuse dilatation of the bile duct to the periphery. The endoscopic biopsy specimen showed no malignant cells. Positron emission tomography-CT showed a focal hypermetabolic lesion (SUVmax 4.2) in and around the proximal CBD area. With the impression of proximal CBD cancer, we performed segmental resection of the extrahepatic bile duct. Histopathology demonstrated marked sclerosis with diffuse lymphoplasmacytic infiltration and some eosinophils. Immunohistochemical staining for IgG4 showed increased positivity in some areas (up to 30/high-power field) and IgG4+/IgG+ cell ratio as 30%-50%. Pathologists’ impression was IgG4-related sclerosing disease. Follow-up serum IgG4 levels were continuously elevated; however, no evidence of relapse or other organ involvement related to IgG4-RSC presented.

CONCLUSION

Isolated and mass-forming IgG4-RSC displays striking similarity with cholangiocarcinoma. To avoid unnecessary major surgery, high index of suspicion is needed.

Diagnosing Biliary Strictures: Distinguishing IgG4-Related Sclerosing Cholangitis From Cholangiocarcinoma and Primary Sclerosing Cholangitis

Biliary strictures caused by inflammation or fibrosis lead to jaundice and cholangitis which often make it difficult to distinguish malignant strictures. In cases when malignancy cannot be excluded, surgery is often performed. The concept of immunoglobulin G4 (IgG4)-related sclerosing cholangitis (SC) as a benign biliary stricture was recently proposed. The high prevalence of the disease in Asian countries has resulted in multiple diagnostic and treatment guidelines; however, there is need to formulate a standardized diagnostic strategy among various countries considering the utility, invasiveness, and cost-effectiveness. We evaluated accuracies of various diagnostic modalities for biliary strictures comparing pathology in the Delphi meetings which were held in Rochester, MN. The diagnostic utility for each modality was graded according to the experts, including gastroenterologists, endoscopists, radiologists, and pathologists from the United States and Japan. Diagnostic utility of 10 modalities, including serum IgG4 level, noninvasive imaging, endoscopic ultrasound, endoscopic retrograde cholangiopancreatography-related diagnostic procedures were advocated and the reasons were specified. Serum IgG4 level, noninvasive imaging, diagnostic endoscopic ultrasound and intraductal ultrasonography under endoscopic retrograde cholangiopancreatography were recognized as useful modalities for the diagnosis. The information in this article will aid in the diagnosis of biliary strictures particularly for distinguishing IgG4-SC from cholangiocarcinoma and/or primary SC.

Systemic IgG4-Related Disease Masquerading as Cholangiocarcinoma: A Case Report Underscoring the Importance of Medical History

BACKGROUND Immunoglobulin (Ig) G4-related disease is a rare disease of unknown pathophysiology, which can affect multiple organs leading to tissue fibrosis and organ failure. The present case report describes a patient with systemic IgG4-related disease (IgG4-RD) that occurred over a 1-year period and affected multiple organs at different times. Imaging studies, interventional procedures, changes in laboratory parameters, and histopathology demonstrate the novel and known aspects of this disease before and during prednisolone monotherapy and in combination with azathioprine. CASE REPORT A 64-year-old man presented with weight loss and painless jaundice, which was highly suspicious for cholangiocarcinoma. A thorough medical history together with laboratory tests, imaging procedures, and endoscopic interventions confirmed that surgery was not needed and led to the final diagnosis of histologically-confirmed, IgG4-related sclerosing cholangitis and autoimmune pancreatitis type 1. Other typical organ manifestations of systemic IgG4-RD were diagnosed through a thorough medical review, which led to immunohistochemical reevaluation of past surgical specimens. Besides the IgG4-related organ manifestations, which can include periorbital xanthelasmas, our patient developed a pulmonary adenocarcinoma 6 years after the initial clinical onset of IgG4-RD. After immunosuppressive treatment with prednisolone alone and subsequently in combination with azathioprine, the patient's IgG4-RD resolved. CONCLUSIONS Interdisciplinary collaboration is required to diagnose IgG4-RD that involves multiple organs. Patient medical history remains crucial for diagnosis and attention should be paid to avoiding unnecessary surgery. Tumors (lung adenocarcinomas) and xanthelasmas can develop because of IgG4-RD. Glucocorticoids and additional azathioprine may be advisable for maintenance treatment.

IgG4-Related Sclerosing Cholangitis Mimicking Cholangiocarcinoma

IgG4-related sclerosing cholangitis (IgG4-SC) is a relatively newly identified disease that is frequently associated with autoimmune pancreatitis. The differential diagnosis between cholangiocarcinoma, primary sclerosing cholangitis, and IgG4-SC can be challenging due to significant overlap among the clinical and imaging characteristics. We report the case of a 71-year-old woman who was diagnosed with IgG4-related disease based on increased serum IgG4 levels, imaging, and clinical presentation, which showed systemic involvement, including sclerosing cholangitis and kidneys. The patient presented with chronic jaundice. Magnetic resonance imaging revealed bile duct strictures and the dilatation of upstream bile ducts, smooth wall thickening with uniform enhancement in the delayed phase, and no vascular infiltration. Multiple low-density, wedge-shaped areas were identified in both kidneys, which were hypointense on T2-weighted images and hyperintense on diffusion-weighted images. The serum IgG4 levels of this patient were elevated to nearly 10-fold the normal upper limit. A diagnosis of IgG4-SC associated with IgG4-related kidney was made. Based on this case, pre-surgery IgG4 serum treatment in patients with non-malignant bile duct stenosis was recommended to exclude IgG4-SC.

Usefulness of ultrasonography to assess the response to steroidal therapy for the rare case of type 2b immunoglobulin G4-related sclerosing cholangitis without pancreatitis: A case report

BACKGROUND

A type 2b immunoglobulin G4 (IgG4)-related sclerosing cholangitis (SC) without autoimmune pancreatitis is a rare condition with IgG4-SC. While the variety of the imaging modalities have tested its usefulness in diagnosing the IgG4-SC, however, the usage of ultrasonography for the assessment of the response to steroidal therapy on the changes of bile duct wall thickness have not been reported in the condition. Therefore, the information of our recent case and reported cases have been summarized.

CASE SUMMARY

We report the case of an 82-year-old Japanese man diagnosed with isolated IgG4-related SC based on the increase of serum IgG4, narrowing of the bile duct, its wall thickness, no complication of autoimmune pancreatitis, and IgG4 positive inflammatory cell infiltration to the wall with the fibrotic changes. The cholangiogram revealed type 2b according to the classification. Corticosteroid treatment showed a favorable effect, with the smooth decrease in serum IgG4 and the improvement of the bile duct wall thickness.

CONCLUSION

As isolated type 2b, IgG4-SC is rare, the images, histological findings, and clinical course of our case will be helpful for physicians to diagnose and treat the new cases appropriately.

A Resected Case of Follicular Cholangitis That Was Positive on 18F-fluorodeoxyglucose-positron Emission Tomography

We experienced a case of follicular cholangitis that was positive on fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG-PET). A 70-year-old man was admitted for jaundice. Endoscopic retrograde cholangiography showed stenosis of the middle to upper choledocus. ¹⁸F-FDG-PET depicted a localized hot spot at the stenotic lesion (maximum standardized uptake value = 8.2). Although no malignant findings were found in the cytology or on a bile duct biopsy, malignancy could not be excluded, so surgical treatment was performed. Follicular cholangitis is a new, rare disease that causes severe biliary stricture. Only 11 cases of follicular cholangitis have been reported, including the present case.

Pathological characteristics and diagnosis of IgG4-related disease

IgG4-related disease (IgG4-RD) has been accepted as a distinct entity in various fields. It is being increasingly diagnosed and treated in routine practice. However, difficulties are still associated with the diagnostic process. Serum IgG4 elevations and imaging studies are useful, but not entirely diagnostic for this condition. Therefore, a pathological examination still plays an important role. Three characteristic microscopic changes are dense lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. IgG4 immunostaining reveals many IgG4-positive plasma cells and an IgG4/IgG-positive cell ratio of more than 40%. In addition to the number and ratio of IgG4-positive plasma cells, the diffuse distribution of positive plasma cells needs to be confirmed because IgG4-positive plasma cells may focally aggregate in many other conditions. In small biopsy samples, it is important to recognize not only characteristic findings, but also microscopic changes that are unlikely to occur in IgG4-RD because the identification of the latter findings leads to the exclusion of this condition. Another challenging field regards the diagnosis of long-standing disease. Along with disease progression, inflammatory infiltrate decreases, while storiform fibrosis and obliterative phlebitis are suspected to persistently exist. Therefore, the recognition of the latter two findings will be a diagnostic clue. Given the general suspicion that IgG4-RD has recently been over-diagnosed, precise tissue examinations based on the proposed standards and close clinicopathological correlations are crucial.

Peribiliary glands: development, dysfunction, related conditions and imaging findings

Peribiliary glands are minute structures that are distributed along the intrahepatic large bile ducts, extrahepatic bile duct, and cystic duct. These glands regulate many physiological functions, such as enzyme secretion. Pancreatic exocrine tissues and enzymes are often observed in peribiliary glands; thus, peribiliary glands are involved in enzyme secretion. As such, these glands can be affected by conditions such as IgG4-related sclerosing cholangitis based on commonalities with their pancreatic counterparts. Cystic changes in peribiliary glands can occur de novo, as part of a congenital syndrome, or secondary to insults such as alcoholic cirrhosis. Biliary tree stem/progenitor cells have recently been identified in peribiliary glands. These cells are involved in turnover and regeneration of biliary epithelia as well as in sclerosing reactions in some pathological conditions, such as primary sclerosing cholangitis and hepatolithiasis. Notably, hepatolithiasis is involved in mucin secretion by the peribiliary glands. Additionally, these cells are associated with the manifestation of several neoplasms, including intraductal papillary neoplasm, cystic micropapillary neoplasm, and cholangiocarcinoma. Normal peribiliary glands themselves are particularly small structures that cannot be recognized using any available imaging modalities; however, these glands are closely associated with several diseases, as mentioned above, which have typical imaging features. Therefore, knowledge of the basic pathophysiology of peribiliary glands is helpful for understanding biliary diseases associated with the peribiliary glands.

Immune-related adverse reactions in the hepatobiliary system: second-generation check-point inhibitors highlight diverse histological changes

AIMS

Immune check-point inhibitors are known to cause immune-mediated adverse liver injury, but our knowledge is mainly based on cases treated with ipilimumab or nivolumab.

METHODS AND RESULTS

Clinicopathological features of 10 patients with hepatobiliary adverse reactions caused by second-generation drugs, pembrolizumab (n = 6) and atezolizumab (n = 4), were reviewed. Liver dysfunction developed during a median period of 3.5 weeks after administration of the check-point inhibitor (3 days-1 year). Antinuclear antibodies were detected in two patients at a low titre (1/80), and serum IgG concentrations were also only mildly elevated in two patients. Liver biopsies showed panlobular hepatitis (n = 5), cholangiopathic changes (n = 2), granulomatous injury (n = 2) and bland cholestasis (n = 1). Two cases of cholangiopathy (both pembrolizumab-treated) showed diffuse sclerosing cholangitis on imaging, and one also presented lymphocytic cholangitis resembling primary biliary cholangitis on biopsy. In two atezolizumab-treated cases, Küpffer cells were hyperplastic and aggregated, forming microgranulomas. Confluent necrosis and eosinophilic or plasma cell infiltration were rare. On immunostaining, the ratio of CD8⁺ /CD4⁺ cells was 12.2 ± 5.1, which was significantly higher than that in autoimmune hepatitis (2.7 ± 1.1; P < 0.001) or idiosyncratic drug-induced liver injury (5.0 ± 1.1; P = 0.014). All patients responded to steroid therapy, but it was less effective in patients with sclerosing cholangitis.

CONCLUSIONS

Pembrolizumab and atezolizumab manifested not only lobular hepatitis but also sclerosing cholangitis, lymphocytic duct injury and granulomatous hepatitis, probably representing various impaired cellular functions in CD8⁺ lymphocytes and macrophages due to blockage of PD-1-PD-L1 interaction.

IgG4-Related Sclerosing Cholangitis: A Clinical and Imaging Review

OBJECTIVE. The purpose of this article is to present the pathologic and clinical features of IgG4-related sclerosing cholangitis (ISC), illustrate the associated imaging findings, and discuss treatment of the disorder. CONCLUSION. ISC is an inflammatory disorder involving the biliary system and resulting in strictures. Although often associated with autoimmune pancreatitis, it may be an isolated disease. Differentiation of ISC from other forms of cholangitis and cholangiocarcinoma is difficult but necessary for management. Imaging is important in diagnosing and assessing the extent of disease and planning a management strategy.

Secondary Sclerosing Cholangitis in Critically Ill Patients: An Underdiagnosed Entity

Secondary sclerosing cholangitis in critically ill patients (SSC-CIP) is a recently identified cholestatic liver disease occurring in patients without prior history of hepatobiliary disease, after receiving treatment in the intensive care unit (ICU) in different settings, including cardiothoracic surgery, infection, trauma, and burns. It is a rare entity, being estimated to occur in 1/2,000 patients in an ICU; however, it is a dismal condition, with up to half of the patients dying during the ICU stay and with rapid progression to liver cirrhosis over weeks to months. SSC-CIP should be considered in the differential diagnosis of cholestasis in the ICU, particularly when cholestasis persists after recovery from the critical event. Diagnosis is established with magnetic resonance cholangiopancreatography or endoscopic retrograde cholangiopancreatography showing dilations and stenoses of the intrahepatic bile ducts as well as biliary casts. No available treatment has been shown to slow the rapid progression of the disease, and liver transplant referral should be considered early after the diagnosis of SSC-CIP. Increased awareness and timely diagnosis are crucial in order to improve the current appalling outcome.

Pancreatobiliary Versus Head and Neck Manifestations in Immunoglobulin G4-related Disease: Distinct Subsets of the Same Disease?

OBJECTIVES

We compared the clinical profiles and organ manifestations of the commonly encountered immunoglobulin G4-related diseases (IgG4-RDs) on either side of the diaphragm: head and neck (HN) versus pancreatobiliary (PB) in IgG4-RD.

METHODS

From the Mayo Clinic, Rochester, database, we identified 53 HN and 88 PB IgG4-RD based on the first affected organ manifestation.

RESULTS

Compared with HN IgG4-RD, subjects with PB IgG4-RD were likely to be older (median, 64.8 vs 50.2 years; P < 0.0001), male (83% vs 60.4%; P = 0.003), and with a shorter duration of follow-up (24.4 vs 48.7 months; P < 0.0001). In HN versus PB-IgG4-RD orbital, lacrimal gland, submandibular, parotid gland, asthma, and sinusitis manifestations were more common (77% vs 4.5%, 21% vs 0%, 32% vs 8%, 13% vs 0%, 36% vs 9%, and 51% vs 6.8%; P < 0.0001, respectively), whereas lung manifestations were similar (13.2% vs 5.6%; P = 0.12). In contrast, in PB versus HN IgG4-RD, pancreas and biliary were more frequent (98.8% vs 15%, 56.8% vs 3.7%; P < 0.0001), whereas renal lesions were similar (12.5% vs 7.5%; P = 0.36).

CONCLUSION

Pancreatobiliary and HN IgG4-RD have distinct clinical profiles. Proximity matters in other organ involvement in IgG4-RD, and organs involved tend to cluster close to each.

Immunoglobulin G4-related sclerosing cholangitis

Immunoglobulin (Ig)G4-related sclerosing cholangitis (IgG4-SC) is a biliary tract manifestation of IgG4-related diseases (IgG4-RD); a subgroup of SC defined as a condition with progressive stenosis and destruction of the bile ducts due to diffuse inflammation and fibrosis. IgG4-SC is clinically characterized by the (a) chronic elevation of cholestatic enzyme levels, (b) significant elevation of serum IgG4 levels, (c) diffuse or segmental narrowing of intra and/or extra hepatic bile ducts with thickening of the bile duct wall in imaging studies, (d) marked lymphoplasmacytic and IgG4-positive plasma cell infiltration and fibrosis in histology, (e) presence of IgG4-RD in other organs, mainly involving autoimmune pancreatitis, and (f) excellent response to corticosteroids. The diagnosis of IgG4-SC is based on a combination of these findings. Although the IgG4-SC diagnosis is different from that of primary sclerosing cholangitis (PSC) or biliary and pancreatic malignancies, it is extremely important to diagnose or suspect IgG4-SC appropriately; as the incorrect diagnosis of PSC or malignant diseases may lead to the progression of fibrosis in patients due to untreated chronic cholestasis, or to unnecessary major surgical resections. Although its etiology remains unclear, recent studies of IgG4-SC have attempted to clarify the roles of the IgG4 molecule and novel autoantibodies detected in patients with IgG4-SC.

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.

Relapse patterns and predictors of IgG4-related diseases involved with autoimmune pancreatitis: A single-center retrospective study of 115 patients

OBJECTIVE

Autoimmune pancreatitis is an autoimmune disorder accompanied by clinicopathological manifestations that have been established as immunoglobulin (IgG)4-related diseases (IgG4-RD). Other IgG4-RD are often involved with autoimmune pancreatitis. They sometimes relapse despite a favorable response to steroid therapy. This study aimed to clarify the patterns and risk factors for extrapancreatic relapse.

METHODS

We reviewed the data of 115 patients diagnosed with definite autoimmune pancreatitis type 1 and followed up for > 1 year. We analyzed two items: the timing and pattern of extrapancreatic relapse, and risk factors for relapse with three common manifestations: IgG4-related sclerosing cholangitis (SC), IgG4-related dacryoadenitis and sialadenitis (DS), and IgG4-related retroperitoneal fibrosis (RF).

RESULTS

Remission was achieved in all patients, except one. The extrapancreatic relapse rates were 11.0%, 19.7%, and 40% within 3, 5, and 10 years, respectively. Of 26 patients with extrapancreatic relapse, nine (34.6%) relapsed with a new IgG4-RD. Based on multivariate analysis, the interval between symptom onset and steroid initiation, and the presence of RF at onset were significant risk factors for relapse with SC and RF, respectively.

CONCLUSIONS

Our results indicate that they may be various extrapancreatic relapse patterns especially in autoimmune pancreatitis with other organ involvement. Patients with a delayed initiation of steroids or RF at onset should be carefully followed up as high-risk groups for SC and RF relapse.

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.

Type 1 and Type 2 Autoimmune Pancreatitis: Distinctive Clinical and Pathological Features, But Are There Any Differences at Magnetic Resonance? Experience From a Referral Center

OBJECTIVES

This study aimed to evaluate magnetic resonance imaging findings of autoimmune pancreatitis (AIP) and to find radiological patterns that could differentiate type 1 and type 2 AIP.

METHODS

Eighty-four patients with diagnosis of AIP were enrolled. Image analysis included pancreatic signal intensity abnormalities, enhancement pattern, extrapancreatic involvement, and main pancreatic duct alterations.

RESULTS

Pancreatic parenchyma resulted in hypointensity on T1-weighted images in 65 (98.5%) of 66 cases in type 1 and in 17 (94.5%) of 18 in type 2 (P > 0.05) and in hyperintensity on T2-weighted images in 41 (62%) of 66 and in 15 (83.4%) of 18, respectively (P > 0.05). Lesions were hypovascular in 64 (97%) of 66 cases in type 1 and in 16 (88.9%) of 18 in type 2 with delayed contrast retention in 56 (84.8%) of 66 and in 17 (94.5%) of 18, respectively (P > 0.05). Autoimmune cholangitis was found in 29 (43.9%) of 66 patients with type 1 and in 3 (16.7%) of 18 with type 2 (P = 0.02); renal involvement was observed in 20 (30.3%) of 66 and 1 (5.5%) of 18, respectively (P = 0.02). Both subtypes presented with multiple stenoses (P > 0.05). Dilation of upstream duct was more frequent in type 1 (P = 0.02).

CONCLUSIONS

Magnetic resonance imaging is useful in detecting extrapancreatic involvement, typically seen in type 1. Dilation of the upstream duct suggests type 1 AIP.

A good response to steroid therapy in IgG4-related sclerosing cholangitis: a case report

IgG4-related sclerosing cholangitis is a rare autoimmune liver disease. Biliary tract imaging, serum IgG4 concentration, and histopathological examination are the major diagnostic criteria for IgG4-related sclerosing cholangitis. In this paper, we report a male patient with yellowish skin, in whom classical liver-protection drugs were initially given, but the efficacy was poor. After that, IgG4-related sclerosing cholangitis was diagnosed, and he achieved a good response to steroid therapy.

The endoscopist and malignant and non-malignant biliary obstruction

Patients with biliary strictures often represent a diagnostic and therapeutic challenge, due to the site and complexity of biliary obstruction and wide differential diagnosis. Multidisciplinary decision making is required to reach an accurate and timely diagnosis and to plan optimal care. Developments in endoscopic ultrasound and peroral cholangioscopy have advanced the diagnostic yield of biliary endoscopy, and novel optical imaging techniques are emerging. Endoscopic approaches to biliary drainage are preferred in most scenarios, and recent advances in therapeutic endoscopic ultrasound allow drainage where the previous alternatives were only percutaneous or surgical. Here we review recent advances in endoscopic practice for the diagnosis and management of biliary strictures. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni and Peter Jansen.

Hilar cholangiocarcinoma associated with immunoglobulin G4-positive plasma cells and elevated serum immunoglobulin G4 levels

Immunoglobulin G4 (IgG4)‐related disease is a fibroinflammatory systemic disorder with multiorgan involvement. Proximal bile duct involvement results in IgG4‐related sclerosing cholangitis, which is characterized by a lymphoplasmacytic infiltrate with abundant IgG4‐positive plasma cells and fibrosis. Differentiating between cholangiocarcinoma and IgG4‐sclerosing cholangitis can present a diagnostic dilemma. We describe an unusual presentation of a hepatic mass meeting multiple criteria for IgG4‐sclerosing cholangitis but was ultimately found to be cholangiocarcinoma. Several published case reports describe patients with suspected cholangiocarcinoma who are later found to have IgG4‐sclerosing cholangitis, but few reports have demonstrated the reverse. Distinguishing between cholangiocarcinoma and IgG4‐sclerosing cholangitis is challenging, and a high clinical suspicion for cholangiocarcinoma must always be maintained. (Hepatology Communications 2018;2:349‐353)

Rituximab Induction to Prevent the Recurrence of PSC After Liver Transplantation-The Lessons Learned From ABO-Incompatible Living Donor Liver Transplantation

Background

Multiple studies have failed to reveal an effective method for preventing the recurrence of primary sclerosing cholangitis (PSC) after liver transplantation (LTx). A national study conducted in Japan revealed several risk factors for the recurrence after living donor LTx (LDLTx); however, recipients of ABO-blood type incompatible (ABO-I) LTx were excluded from the previous analysis. In the present study, we investigated the efficacy of an immunosuppressive protocol in ABO-I LTx on the recurrence of PSC after LDLTx.

Methods

We conducted a national survey and analyzed the outcome of recipients who underwent ABO-I LDLTx for PSC (n = 12) between 1994 and 2010 in 9 centers and compared the outcome with that of ABO-compatible LDLTx for PSC (n = 96). The key elements of the immunosuppressive regimen in ABO-I LTx are plasma exchange sessions to remove existing antibodies, and the use of immunosuppression to control humoral immunity. Rituximab was added to the immunosuppression regimen from 2006 onward; 5 patients received rituximab perioperatively.

Results

All 7 recipients who underwent ABO-I LDLTx before 2006 (who did not receive rituximab) died of infection (n = 3), antibody-mediated rejection (n = 1), ABO-incompatibility associated cholangiopathy (n = 1) or recurrence of PSC (n = 2). In contrast, we found that all 5 recipients from 2006 (who were treated with rituximab) retained an excellent graft function for more than 7 years without any recurrence of PSC.

Conclusions

The findings of this study shed light on the efficacy of a novel strategy to prevent the recurrence of PSC and the possible mechanisms provided by rituximab treatment are discussed.

Analysis of clinical characteristics and treatment of immunoglobulin G4-associated cholangitis: A retrospective cohort study of 39 IAC patients

Immunoglobulin (Ig)G4-associated cholangitis (IAC) is one of the common organ manifestations of IgG4-related systemic disease (ISD). IAC and autoimmune pancreatitis (AIP) may mimic sclerosing cholangitis, cholangiocarcinoma, or pancreatic carcinoma. Diagnosis is based on a combination of clinical, biochemical, radiological, and histological findings.To study the clinical presentation of and treatment strategy for IAC, we reviewed clinical, serologic, and imaging characteristics, as well as treatment response, in 39 patients with IAC. The majority of patients were men (82%). Clinical features on presentation included obstructive jaundice in 26 patients (67%) and abdominal pain in 20 (51%). Positive IgG4 immunostaining was seen in 27 patients. The median serum IgG4 level before treatment was 769.4 mg/dL (range, 309.1-1229.7 mg/dL). After the steroid therapy, the median serum IgG4 level in 23 patients was 247.0 mg/dL (range, 139.0-355.0 mg/dL). Cholangiograms were available in 36 (92%) patients. Stenosis of the lower part of the common bile duct was found in 26 of 39 patients. Stenosis was diffusely distributed in the intra- and extrahepatic bile ducts in 14 of 39 patients. Additionally, strictures of the bile duct were detected in the hilar hepatic lesions in 27 of 39 patients. AIP was the most frequent comorbidity (35/39 in this study) of IAC. Other affected organs included eyes (n = 6), salivary glands (sialadenitis, n = 10), lymph nodes (mediastinal and axillary, n = 3), kidneys (n = 2), and the retroperitoneum (retroperitoneal fibrosis, n = 2).Regarding treatment, 29 patients were treated with steroids, of whom one underwent pancreatoduodenectomy, and one underwent choledochojejunostomy. Eight patients were treated with biliary stents. The remaining 19 patients took prednisolone alone. Eight patients achieved spontaneous resolution. Four patients with suspected pancreatic cancer or cholangiocarcinoma underwent surgery, including 2 patients who also received postoperative steroids. All patients were regularly followed up for 9 to 36 months. Only 2 patients in the steroids treatment group relapsed to manifest obstructive jaundice and high serum IgG4 levels. These 2 patients were treated with steroids and biliary stents, resulting in complete remission.We also review the diagnostic and therapeutic management and discuss recent pathophysiological findings, which might aid in understanding the molecular mechanisms contributing to IAC and other manifestations of IgG4-related diseases (IgG4-RD). Biomarkers that are more accurate are needed to correctly diagnose IAC and prevent misdiagnoses and unnecessary therapeutic interventions.

IgG4-related disease: with emphasis on the biopsy diagnosis of autoimmune pancreatitis and sclerosing cholangitis

In 2011, chronic fibroinflammatory processes occurring simultaneously or metachronously in various organs and associated with elevated IgG4 serum levels and/or tissue infiltration with IgG4-positive plasma cells have been recognized as manifestations of a systemic disorder called IgG4-related disease (IgG4-RD). The histologic key findings are lymphoplasmacytic infiltration rich in IgG4-positive plasma cells combined with storiform fibrosis and obliterative phlebitis. Among the organs mainly affected by IgG4-RD are the pancreas and the extrahepatic bile ducts. The pancreatic and biliary alterations have been described under the terms autoimmune pancreatitis (AIP) and sclerosing cholangitis, respectively. These diseases are currently more precisely called IgG4-related pancreatitis (or type 1 AIP to distinguish it from type 2 AIP that is unrelated to IgG4-RD) and IgG4-related sclerosing cholangitis (IgG4-related SC). Clinically and grossly, both diseases commonly imitate pancreatic and biliary adenocarcinoma, tumors that are well known for their dismal prognosis. As IgG4-RD responds to steroid treatment, making a resection of a suspected tumor unnecessary, a biopsy is often required to establish the preoperative diagnosis. This review discusses the morphologic spectrum of IgG4-related pancreatitis and IgG4-related SC and focuses on the biopsy relevant histologic features for the diagnosis and differential diagnosis of these diseases.

Clinical Features, Response to Treatment, and Outcomes of IgG4-Related Sclerosing Cholangitis

BACKGROUND & AIMS

Immunoglobulin G4 sclerosing cholangitis (IgG4-SC) is a biliary tract manifestation of IgG4-related systemic disease. We investigated the demographics, clinical features at presentation, treatment response, and outcomes of IgG4-SC using data from a large-scale survey in Japan.

METHODS

We performed a retrospective cohort study of 527 patients with IgG4-SC (436 female; median age, 66.2 years; range, 23-89 years) in Japan from 2000 to 2015. Data on patient demographics, presentation, treatment response, and outcomes were collected from questionnaires given to patients at 211 referral centers in Japan in 2015. Patients were diagnosed with IgG4-SC based on the clinical diagnostic criteria established by the Japanese Biliary Association in 2012. Patients were followed for a median of 4.1 ± 3.1 years. Survival was assessed using the Kaplan-Meier curve and log-rank test.

RESULTS

Symptoms at presentation included jaundice (35% of patients) and pruritus (13% of patients); 28% of patients were asymptomatic. It was extremely rare for patients with IgG4-SC to present with symptoms of decompensated cirrhosis. At presentation, serum levels of IgG4 were increased (>135 mg/dL) in 84% of patients. Response to prednisolone was excellent in 90% of patients. No patients received liver transplants, and cholangiocarcinoma was found in only 4 patients (0.7%). Restenosis of bile ducts was observed in 19% of patients but did not affect overall survival.

CONCLUSIONS

In a retrospective cohort study of 527 patients with IgG4-SC in Japan, we found the disease to be benign. Most patients (90%) respond to treatment with prednisolone and few develop decompensated cirrhosis or cholangiocarcinoma.

IgG4-related Disease and the Liver

Pathologists are likely to encounter IgG4-related disease in several organ systems. This article focuses on helping pathologists diagnose IgG4-related disease in the hepatobiliary system. Missing the diagnosis can result in unnecessary organ damage and/or unnecessary surgical and cancer therapy. In the liver, tumefactive lesion(s) involving the bile ducts with storiform fibrosis and an IgG4-enriched lymphoplasmacytic infiltrate are highly concerning for IgG4-related disease. The recent identification of oligoclonal populations of T cells and B cells in IgG4-related disease may lead to molecular tests, new therapeutics, and a greater mechanistic understanding of the disease.

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of IgG4-related diseases. Small-duct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor- α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.

No negative impact of serum IgG4 levels on clinical outcome in 435 patients with primary sclerosing cholangitis from Japan

BACKGROUND

Several studies have demonstrated that elevated serum IgG4 levels are associated with poor outcomes of primary sclerosing cholangitis (PSC), but the impact of serum IgG4 levels on PSC remains controversial. In this study, we aimed to determine prognostic factors of patients with PSC and to investigate the association between serum IgG4 levels and the clinical features and prognosis of PSC in a Japanese cohort.

METHODS

We retrospectively analyzed follow-up data for 435 patients with PSC (UMIN000018438). Patients with distinct etiologies of sclerosing cholangitis including IgG4-related sclerosing cholangitis (IgG4-SC) were excluded from this study.

RESULTS

Serum IgG4 levels were tested at the time of diagnosis in 216 of 435 patients with PSC, and were elevated in 27 patients (>134 mg/dl, 12.5%). Clinical features at diagnosis were comparable between patients with normal and elevated serum IgG4 levels, with the exception of serum albumin. The overall and liver-transplantation free survival rate was comparable between the groups. Multivariate analysis indicated that age, albumin, and bilirubin, but not IgG4, at the time of diagnosis affected PSC prognosis.

CONCLUSIONS

The current study showed that serum IgG4 levels at diagnosis do not affect PSC prognosis in a Japanese cohort that excluded patients with IgG4-SC.

Recent advances in understanding and managing IgG4-related disease

IgG4-related disease was only recently discovered, so its description, management, and new discoveries related to its etiology are rapidly evolving. Because IgG4 itself is a unique antibody which is intimately related to the diagnosis of the disease, the role of plasmablasts in the pathophysiology remains an active area of discussion. Recent studies have uncovered a possible role for CD4-positive cytotoxic T lymphocytes, T follicular helper cells, and M2 macrophages. The clinical presentation is variable and can be vague, as this disease affects many organs and new presentations are continuing to be described. The diagnosis depends on clinical and histopathological assessment. The mainstay of treatment is with glucocorticoids, but rituximab has recently shown promise. Monitoring disease activity using imaging modalities (including positron emission tomography) and serum markers is imperative, as relapses are common. IgG4-related disease spans many medical disciplines but is a treatable condition with which all clinicians should be familiar.

Isolated IgG4-related sclerosing cholangitis misdiagnosed as malignancy in an area with endemic cholangiocarcinoma: a case report

Background

The most common cause of perihilar obstruction is cholangiocarcinoma, especially in Thailand. Benign perihilar stricture represents less than 20% of cases. IgG4-related disease and IgG4-related sclerosing cholangitis, however, have been receiving increased recognition. Isolated IgG4-related sclerosing cholangitis is less common. The preoperative diagnosis of IgG4-related sclerosing cholangitis without pancreatic involvement is very difficult because the clinical presentation and preoperative evaluation are extremely difficult to distinguish from perihilar cholangiocarcinoma.

Case presentation

We report the case of a 56-year-old man who presented with obstructive jaundice with preoperative imaging showing proximal common bile duct obstruction. He underwent right lobe liver hepatectomy with extrahepatic bile duct resection and regional lymph node dissection due to high suspicion of malignancy. The pathological report showed severe acute and chronic inflammation of the bile duct with morphology and immunohistochemistry suggestive of IgG4-related sclerosing cholangitis.

Conclusions

IgG4-related sclerosing cholangitis with perihilar obstruction should be considered even in areas where cholangiocarcinoma is endemic.

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.

Recent advances in the diagnosis and treatment of primary biliary cholangitis

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

Advances in research of immunoglobulin G4-related sclerosing cholangitis

Immunoglobulin G4 (IgG4)-related sclerosing cholangitis is a special form of cholangitis. As an autoimmune disease, IgG4-related sclerosing cholangitis has no specific clinical manifestations, and its pathogenesis remains unclear. In patients with this disease, serum concentration of IgG4 is elevated, intrahepatic or extrahepatic bile duct stenosis associated with biliary wall thickening is often revealed by biliary imaging, autoimmune diseases such as autoimmune pancreatitis may be present, and massive IgG4 positive plasma cell infiltration and widespread bile duct wall fibrosis are often showed by histopathological examination. It is often difficult to differentiate IgG4-related sclerosing cholangitis from primary sclerosing cholangitis, secondary sclerosing cholangitis and bile duct cancer. However, the disease is sensitive to hormone therapy. This article will review the current advances in research of IgG4-related sclerosing cholangitis.

Adult bile duct strictures: differentiating benign biliary stenosis from cholangiocarcinoma

Biliary epithelial cells preferentially respond to various insults under chronic pathological conditions leading to reactively atypical changes, hyperplasia, or the development of biliary neoplasms (such as biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, and cholangiocarcinoma). Moreover, benign biliary strictures can be caused by a variety of disorders (such as IgG4-related sclerosing cholangitis, eosinophilic cholangitis, and follicular cholangitis) and often mimic malignancies, despite their benign nature. In addition, primary sclerosing cholangitis is a well-characterized precursor lesion of cholangiocarcinoma and many other chronic inflammatory disorders increase the risk of malignancies. Because of these factors and the changes in biliary epithelial cells, biliary strictures frequently pose a diagnostic challenge. Although the ability to differentiate neoplastic from non-neoplastic biliary strictures has markedly progressed with the advance in radiological modalities, brush cytology and bile duct biopsy examination remains effective. However, no single modality is adequate to diagnose benign biliary strictures because of the low sensitivity. Therefore, understanding the underlying causes by compiling the entire clinical, laboratory, and imaging data; considering the under-recognized causes; and collaborating between experts in various fields including cytopathologists with multiple approaches is necessary to achieve an accurate diagnosis.

The changing faces of cholangitis

A variety of diseases are included under the umbrella term ‘cholangitis’, including hepatobiliary diseases with an autoimmune pathogenesis (such as primary sclerosing cholangitis, primary biliary cholangitis, and IgG4-associated sclerosing cholangitis) and disease processes associated with intraductal stones and infectious etiologies (such as ascending bacterial cholangitis, recurrent pyogenic cholangitis, and liver fluke-associated cholangitis). Recent advances in the pathophysiologic bases of these disorders, particularly with respect to the autoimmune variety, are allowing improved diagnosis and prognostication as well as providing the opportunity to refine and re-imagine treatment modalities. The aim of this review is to highlight selected advances in cholangitis research that point to novel insights into the pathophysiology, diagnosis, and treatment of this diverse array of disorders.

The Histopathology of IgG4-Related Disease

IgG4-related disease is a multi-organ immune-mediated chronic fibroinflammatory condition characterized by elevated serum IgG4 concentrations, tumefaction, and tissue infiltration by IgG4-positive plasma cells. The exact etiology of IgG4-related disease remains unclear with no known role of the IgG4 molecule itself being identified. Although the pancreas and salivary glands are the main organs affected, the involvement of other organs has also been reported. This multi-organ disease mimics a large number of malignant, infectious, and inflammatory disorders; therefore, a prompt differential diagnosis is important for selecting the right therapeutic strategy. Early steroid therapy assists in preventing tissue fibrosis, parenchymal extinction, and severe functional impairments in the affected organs. The definitive and prompt diagnosis of IgG4-related disease requires both histopathological confirmation and clinicopathological correlations. A histopathological examination is mandatory to exclude neoplastic or inflammatory conditions that mimic IgG4-related disease. The histological changes that occur are basically similar in any organ manifestation, with several site-specific findings being recognized. This chapter summarizes general rules for the pathological examination of IgG4-related disease, as well as the histopathological features and differential diagnoses of major organ manifestations.

The role of intraductal ultrasonography in pancreatobiliary diseases

Intraductal ultrasonography (IDUS) provides real-time, cross-sectional imaging of pancreatobiliary ducts and surrounding structures during endoscopic retrograde cholangiopancreatography using a high-frequency ultrasound (US) transducer. Hence, IDUS has been considered a sensitive tool in the evaluation of suspicious choledocholithiasis and neoplasms, to help distinguish between benign and malignant bile duct strictures or wall thickness, and to assess tumor extension and invasion depth. With the rapid development and enriched choices of sensitive diagnostic modalities include but are not limited to endoscopic US, peroral cholangioscopy, and confocal laser endomicroscopy, it is needed to systematically assess the role of IDUS in the investigation of pancreatobiliary diseases. Some new developments and innovative use of IDUS techniques will be discussed in this paper with the review of literature.