Bile duct involvement in a case of autoimmune pancreatitis successfully treated with an oral steroid

The Clinical Phenotype of Chinese Patients With Autoimmune Pancreatitis Differs Significantly From Western Patients

Aim

To characterize the clinical features of autoimmune pancreatitis (AIP) in China and compare differences between our Chinese cohort and Western cohorts.

Methods

This was a retrospective study of patients with AIP that was carried out in the China-Japan Friendship Hospital between January 2010 and April 2021. We included a total of 50 patients (46 males and 4 females) aged between 27 and 86 years who fulfilled the international Consensus Diagnostic (ICD) Criteria. For comparative purposes, we included data from seven representative Western cohorts.

Result

When comparing Chinese and Western patients, we found that obstructive jaundice was the most frequent initial symptom (68 vs. 43%, P < 0.001). Extra-pancreatic organ involvement was more common in Chinese patients (68 vs. 30%, P < 0.001). Sclerosing cholangitis was the most frequent extrapancreatic lesion (48 vs. 24%, P = 0.001). The elevation of serum IgG4 was more obvious in our cohort (86 vs. 49%, P < 0.001). Conversely, the rates of ANA-positivity were significantly higher in Western populations (17 vs. 50%, P = 0.006). With regards to imaging, diffuse swelling was significantly more common in China (44 vs. 27%, P = 0.021). Steroid therapy was used more frequently in our Chinese patients (84 vs. 59%, P = 0.001). The steroid-response rate was also significantly higher in our Chinese patients (85 vs. 54%, P = 0.001); However, the rate of resection was higher in Western cohorts (2 vs. 31%, P < 0.001). There was no significant difference between the two populations with regards to recurrence rate (33 vs. 33%, P = 1.000).

Conclusion

This study identified significant differences between Chinese and Western populations of patients with AIP. Within the Chinese population, AIP was more likely to have jaundice and extra-pancreatic organ involvement, and elevated serum IgG4 levels. Chinese patients were also showed favorable responses to treatment with glucocorticoids.

An immunoglobulin G4-related sclerosing disease of the small bowel: CT and small bowel series findings

Immunoglobulin G4 (IgG4)-related sclerosing disease is rare and is known to involve various organs. We present a case of histologically proven IgG4-related sclerosing disease of the small bowel with imaging findings on computed tomography (CT) and small bowel series. CT showed irregular wall thickening, loss of mural stratification and aneurysmal dilatation of the distal ileum. Small bowel series showed aneurysmal dilatations, interloop adhesion with traction and abrupt angulation.

IgG4-related disease of the head and neck: CT and MR imaging manifestations

Immunoglobulin G4 (IgG4)-related disease is a recently established systemic disease that commonly involves the head and neck, including the salivary glands, lacrimal glands, orbits, thyroid gland, lymph nodes, sinonasal cavities, pituitary gland, and larynx. Although the definitive diagnosis of IgG4-related disease requires histopathologic analysis, elevated serum IgG4 levels are helpful in making the diagnosis. Because of the proposed clinical diagnostic criteria for this disease, cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance (MR) imaging play an important diagnostic role. CT and MR imaging findings of IgG4-related disease are usually nonspecific. At CT, involved organs may demonstrate enlargement or decreased attenuation; at T2-weighted MR imaging, they may have relatively low signal intensity owing to their increased cellularity and amount of fibrosis. Some pathologic entities involving the head and neck are now considered to be part of the IgG4-related disease spectrum, including idiopathic orbital inflammatory syndrome (inflammatory pseudotumor), orbital lymphoid hyperplasia, Mikulicz disease, Küttner tumor, Hashimoto thyroiditis, Riedel thyroiditis, and pituitary hypophysitis. Because involvement of multiple sites is common in IgG4-related disease, radiologists should be familiar with manifestations of this systemic process outside the head and neck, in organs such as the pancreas, bile ducts, gallbladder, kidneys, retroperitoneum, mesentery, lungs, gastrointestinal tract, and blood vessels. Moreover, IgG4-related disease usually demonstrates a dramatic response to corticosteroid therapy, and radiologists should be familiar with its clinical and imaging manifestations to avoid a delay in diagnosis or unnecessary invasive interventions.

IgG4-related sclerosing disease: autoimmune pancreatitis and extrapancreatic manifestations

Autoimmune pancreatitis is the pancreatic manifestation of IgG4-related sclerosing disease, which recently was recognized as a distinct disease entity. Numerous extrapancreatic organs, such as the bile ducts, gallbladder, kidneys, retroperitoneum, thyroid, salivary glands, lung, mediastinum, lymph nodes, and prostate may be involved, either synchronously or metachronously. Most cases of autoimmune pancreatitis are associated with elevated serum IgG4 levels; extensive IgG4-positive plasma cells; and infiltration of lymphocytes into various organs, which leads to fibrosis. There are several established diagnostic criteria systems that are used to diagnose autoimmune pancreatitis and that rely on a combination of imaging findings of the pancreas and other organs, serologic findings, pancreatic histologic findings, and response to corticosteroid therapy. It is important to recognize multiorgan involvement of IgG4-related sclerosing disease and be familiar with its clinical and imaging features because it demonstrates a favorable response to treatment.

IgG4-related sclerosing disease, an emerging entity: a review of a multi-system disease

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.

IgG4-related sclerosing disease: a critical appraisal of an evolving clinicopathologic entity

An elevated serum titer of immunoglobulin G4 (IgG4), the least common (3% to 6%) of the 4 subclasses of IgG, is a surrogate marker for the recently characterized IgG4-related sclerosing disease. The syndrome affects predominantly middle-aged and elderly patients, with male predominance. The patients present with symptoms referable to the involvement of 1 or more sites, usually in the form of mass lesions. The prototype is IgG4-related sclerosing pancreatitis (also known as autoimmune pancreatitis), most commonly presenting as painless obstructive jaundice with or without a pancreatic mass. Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, but practically any organ-site can be affected, such as retroperitoneum, aorta, mediastinum, soft tissue, skin, central nervous system, breast, kidney, prostate, upper aerodigestive tract, and lung. The patients usually have a good general condition, with no fever or constitutional symptoms. Common laboratory findings include raised serum globulin, IgG, IgG4, and IgE, whereas lactate dehydrogenase is usually not raised. Some patients have low titers of autoantibodies (such as antinuclear antibodies and rheumatoid factor). The disease often shows excellent response to steroid therapy. The natural history is characterized by the development of multiple sites of involvement with time, sometimes after many years. However, the disease can remain localized to 1 site in occasional patients. The main pathologic findings in various extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, accompanied by atrophy and loss of the specialized structures of the involved tissue (such as secretory acini in pancreas, salivary gland, or lacrimal gland). The relative predominance of the lymphoplasmacytic and sclerotic components results in 3 histologic patterns: pseudolymphomatous, mixed, and sclerosing. Immunostaining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). The lymph nodes show multicentric Castleman disease-like features, reactive follicular hyperplasia, interfollicular expansion, or progressive transformation of germinal centers, with the unifying feature being an increase in IgG4+ plasma cells on immunostaining. The nature and pathogenesis of IgG4-related sclerosing disease are still elusive. Occasionally, the disease can be complicated by the development of malignant lymphoma and possibly carcinoma.

Comparison of sclerosing cholangitis with autoimmune pancreatitis and infiltrative extrahepatic cholangiocarcinoma: multidetector-row computed tomography findings

PURPOSE

The aim of this study was to compare multidetector-row computed tomography (MDCT) findings between cases of sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and infiltrative extrahepatic cholangiocarcinoma (IEC).

MATERIALS AND METHODS

We retrospectively assessed MDCT findings from 16 IEC cases and 13 SC-AIP cases. MDCT findings were analyzed with regard to location, length, wall thickness, contour, stricture wall enhancement pattern, proximal duct diameter, and the presence of diffuse concentric thickening in the proximal duct and gallbladder wall thickness.

RESULTS

Stricture length, stricture wall thickness, and proximal duct diameter were significantly smaller for SC-AIP than for IEC: 19.3 +/- 8.7 vs. 31.8 +/- 12.0 mm (P = 0.004), 2.1 +/- 1.3 vs. 4.1 +/- 1.3 mm (P < 0.001), and 9.2 +/- 3.9 vs. 13.3 +/- 5.0 mm (P = 0.012), respectively. SC-AIP was correlated with stricture location in both the intrapancreatic and hilar hepatic bile ducts, concentric stricture contour (P < 0.001), and diffuse concentric thickening of the proximal bile duct (P = 0.010). Overall values of sensitivity, specificity, and accuracy used to distinguish between SC-AIP and IEC for stricture wall thickness of <3.0 mm and concentric contour were 76.9%, 93.8%, and 86.2%, respectively, and 100%, 87.5%, 93.1%, respectively.

CONCLUSION

Concentric contour and stricture wall thicknesses of <3.0 mm may help distinguish between SC-AIP and IEC.

Characteristic findings in images of extra-pancreatic lesions associated with autoimmune pancreatitis

PURPOSE

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by a variety of extra-pancreatic involvements which are frequently misdiagnosed as lesions of corresponding organs. The purpose of this study was to clarify the diagnostic imaging features of extra-pancreatic lesions associated with autoimmune pancreatitis.

MATERIALS AND METHODS

We retrospectively analyzed diagnostic images of 90 patients with autoimmune pancreatitis who underwent computer-assisted tomography, magnetic resonance imaging, and/or gallium-67 scintigraphy before steroid therapy was initiated.

RESULTS

AIP was frequently (92.2%) accompanied by a variety of extra-pancreatic lesions, including swelling of lachrymal and salivary gland lesions (47.5%), lung hilar lymphadenopathy (78.3%), a variety of lung lesions (51.2%), wall thickening of bile ducts (77.8%), peri-pancreatic or para-aortic lymphadenopathy (56.0%), retroperitoneal fibrosis (19.8%), a variety of renal lesions (14.4%), and mass lesions of the ligamentum teres (2.2%). Characteristic findings in CT and MRI included lymphadenopathies of the hilar, peri-pancreatic, and para-aortic regions; wall thickening of the bile duct; and soft tissue masses in the kidney, ureters, aorta, paravertebral region, ligamentum teres, and orbit.

CONCLUSIONS

Recognition of the diagnostic features in the images of various involved organs will assist in the diagnosis of autoimmune pancreatitis and in differential diagnoses between autoimmune pancreatitis-associated extra-pancreatic lesions and lesions due to other pathologies.

Abdominal extrapancreatic lesions associated with autoimmune pancreatitis: Radiological findings and changes after therapy

PURPOSE

To evaluate imaging findings of abdominal extrapancreatic lesions associated with autoimmune pancreatitis (AIP) and changes after steroid therapy.

METHODS AND MATERIALS

This study included nine AIP patients with abdominal extrapancreatic lesions, which were determined by retrospective radiological review. CT (initial and follow-up, n=9) and MR imaging (initial, n=5) were reviewed by two radiologists in consensus to determine imaging characteristics (i.e., size, number, attenuation or signal intensity, and contrast enhancement of the lesions, and the presence of overlying capsule retraction) and evaluate changes with steroid therapy of abdominal extrapancreatic lesions associated with AIP.

RESULTS

The most common abdominal extrapancreatic lesion associated with AIP was retroperitoneal fibrosis (RPF) in six patients. In five patients, CT and MR imaging revealed single or multiple, round- or wedge-shaped, hypoattenuating or hypointense, enhancing lesions in the renal cortex or pelvis. Other lesions included a geographic, ill-defined, hypoattenuating lesion with or without overlying capsule retraction in the liver in two and bile duct dilatation with or without bile duct wall thickening in four. Over a follow-up period of 6-81 months, CT exams of eight patients demonstrated partial or complete improvement of the abdominal extrapancreatic lesions, albeit their improvement in general lagged behind that of the pancreatic lesion.

CONCLUSION

On CT or MR imaging, the abdominal extrapancreatic lesions associated with AIP are various in the retroperitoneum, liver, kidneys and bile ducts, and are reversible with steroid therapy.

Immunoglobulin G4-related sclerosing cholangitis in patients resected for presumed malignant bile duct strictures

Background

Immunoglobulin (Ig) G4-related lymphoplasmacytic sclerosing pancreatitis has been described in the context of autoimmune pancreatitis mimicking distal cholangiocarcinoma. The aim of this study was to assess the occurrence of this entity in benign bile duct strictures in patients resected for presumed hilar cholangiocarcinoma.

Methods

Of 185 patients who had undergone resection of proximal bile ducts on suspicion of hilar cholangiocarcinoma between January 1984 and June 2005, 32 (17·3 per cent) had a benign bile duct stricture on histopathological examination. After re-evaluation, further immunohistochemical analysis was performed on specimens from patients with features of autoimmune-like disease.

Results

The periductal stroma in 15 patients showed features of autoimmune-like disease (diffuse, moderate to severe lymphoplasmacytic infiltration with marked fibrosis). Abundant IgG4-positive plasma cell infiltration around the bile duct lesions was seen in two of these. Although not significant, patients with features of autoimmune-like disease on histological changes showed a higher incidence of recurrent biliary complications than those without (P = 0·250).

Conclusion

Features of autoimmune-like bile duct disease were seen in almost half (15 of 32) of patients with benign hilar strictures resected for presumed hilar cholangiocarcinoma. Frank IgG4-related sclerosing disease was found in only two of the 15 patients with autoimmune-like bile duct disease.

Pancréatite auto-immune

Chronic autoimmune pancreatitis is an entity distinct from all other forms of chronic pancreatitis. It is expressed by signs of acute or chronic pancreatitis, sometimes associated with cholestatic jaundice. In imaging, it may appear as diffuse (duct destructive) or pseudotumoral lesions. These 2 aspects are probably different clinical forms of chronic autoimmune pancreatitis. Some autoimmune diseases are associated with chronic autoimmune pancreatitis, but not consistently. One such disease involves a bile disorder very similar to primary sclerosing cholangitis but responsive to corticosteroid treatment. Pancreatitis may be a sign of intestinal inflammatory diseases (and vice versa): testing for Crohn's disease and ulcerative rectocolitis is justified in patients with idiopathic pancreatitis. Chronic autoimmune pancreatitis must be routinely considered in patients with a pancreatic tumor that is for a clinical, epidemiologic, serologic or imaging reason not completely consistent with pancreatic adenocarcinoma. A short corticosteroid therapy (< 4 weeks) is probably less harmful in a patient with pancreatic adenocarcinoma than pancreatectomy (or chemotherapy) in patients with chronic autoimmune pancreatitis. Diagnosis depends on a body of clinical and radiologic evidence. The diagnostic value of serologic markers and especially of autoantibodies must be clarified in the future.

Sclerosing cholangitis associated with autoimmune pancreatitis

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by irregular narrowing of the pancreatic duct, pancreatic swelling, and a favorable response to corticosteroids, in which the autoimmune mechanism is postulated in the pathogenesis. High serum immunoglobulin (Ig)G4 concentrations and various types of extrapancreatic involvement are prominent features of this disease. Sclerosing cholangitis is a major extrapancreatic lesion of autoimmune pancreatitis that has been regarded as primary sclerosing cholangitis (PSC) complicating chronic pancreatitis. Because sclerosing cholangitis associated with autoimmune pancreatitis (SC-AIP) also favorably responds to corticosteroid therapy, it should be differentiated from PSC. Useful points regarding the differentiation between SC-AIP and PSC are as follows: (i) PSC occurs in younger and SC-AIP in older individuals; (ii) obstructive jaundice is more frequently seen in SC-AIP; (iii) PSC is complicated with inflammatory bowel disease, whereas SC-AIP is complicated with so called extrapancreatic lesions of AIP; (iv) high serum IgG4 concentrations are frequently seen in SC-AIP; (v) a cholangiogram may differentiate the two conditions to some extent; (vi) abundant IgG4-bearing plasma cell infiltration is seen in SC-AIP; and (vii) steroid therapy is effective for SC-AIP. IgG4-related sclerosing cholangitis without pancreatic lesion may be a metachronous phenotype of SC-AIP, and also should be differentiated from PSC. The pathogenesis of AIP and SC-AIP remains unclear. The complement activation system of the classical pathway may be contributing in some cases.

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

BACKGROUND

The present study was undertaken to identify the clinicopathological differences between sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and primary sclerosing cholangitis (PSC).

METHODS

We retrospectively compared the clinical, cholangiographic, and liver biopsy findings between 24 cases of PSC and 24 cases of SC-AIP.

RESULTS

Patient age at the time of diagnosis was significantly lower in the PSC group than in the SC-AIP group. The peripheral blood eosinophil count was significantly higher in the PSC group than in the SC-AIP group, but the serum IgG4 level was significantly higher in the SC-AIP group. Cholangiography revealed band-like strictures, beaded appearance, and pruned-tree appearance significantly more frequently in PSC, whereas segmental strictures and strictures of the distal third of the common bile duct were significantly more common in SC-AIP. Liver biopsy revealed fibrous obliterative cholangitis only in the PSC specimens. No advanced fibrous change corresponding to Ludwig's stages 3 and 4 was observed in any of the SC-AIP specimens. IgG4-positive plasma cell infiltration of the liver was significantly more severe in SC-AIP than in PSC. Subsequent cholangiography showed no improvement in any of the PSC cases, but all SC-AIP patients responded to steroid therapy, and improvement in the strictures was observed cholangio-graphically.

CONCLUSIONS

Based on the differences between the patients' ages and blood chemistry, cholangiographic, and liver biopsy findings, SC-AIP should be differentiated from PSC.

Clinical features of autoimmune pancreatitis

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by a high serum IgG4 concentration, and complications involving various extrapancreatic lesions. It should be emphasized that autoimmune pancreatitis is easily misdiagnosed as pancreatic cancer. This disease predominantly affects elderly men. The major symptom at onset is obstructive jaundice, while severe abdominal pain is rare. Blood tests have shown abnormal results, which could be attributed mainly to the obstructive jaundice. With regard to autoantibodies, the positive rate for the antinuclear antibody is 40%; however, disease-specific autoantibodies are rarely found. About half of the patients with autoimmune pancreatitis have shown exocrine and endocrine dysfunctions. IgG4 is a sensitive and specific marker for diagnosing autoimmune pancreatitis. In differentiating between pancreatic cancer and autoimmune pancreatitis, IgG4 shows a sensitivity of 90%, a specificity of 98%, and an accuracy of 95%. HLA DRB1*0405-DQB1*0401 alleles are significantly associated with autoimmune pancreatitis, and may present a specific peptide which triggers the autoimmune response. Various imaging findings have shown pancreatic swelling, irregular narrowing of the main pancreatic duct, and stenosis of the lower bile duct. Histology shows a significant presence of lymphocytes, plasma cell infiltration, and fibrosis with abundant IgG4-bearing plasma cell infiltration. After corticosteroid treatment, imaging findings and pancreatic functions usually improve significantly. It is probable that autoimmune pancreatitis is an essentially progressive condition resulting in pancreatic stone formation in a similar way to ordinary chronic pancreatitis.

Autoimmune pancreatocholangitis: a series of ten patients

BACKGROUND

During a 10-year period we observed 10 patients who suffered from an inflammatory-fibrosing disease mimicking pancreatic carcinoma and primary sclerosing cholangitis (PSC).

METHODS

A review of the presenting features, the clinical course and the relevant literature.

RESULTS

Ten male patients (mean age 55 years) presented with weight loss, jaundice and pruritus. Pancreatic cancer was suggested by imaging studies, which showed focal or generalized pancreatic enlargement and compression of the distal common bile duct. Cholangiography also demonstrated intrahepatic biliary stenoses consistent with sclerosing cholangitis. None had evidence of IBD. Exocrine pancreatic insufficiency was found in six cases and diabetes in four. Pancreatic histology (n=3) showed fibrosis and extensive inflammatory infiltrates. Immunosuppressive treatment was instituted in five patients. Clinical and biochemical remission occurred in three; in one other patient, previously documented intrahepatic biliary strictures had disappeared after 3 months. One patient had concomitant Sjögren's disease. The clinical features, pancreatic involvement, age at presentation, absence of IBD and response to steroids all plead against a diagnosis of "classical" PSC. The natural course of the disease was highly variable. Thirty-five comparable cases, with a largest series of three, have been reported in the literature. The disease has been associated with Sjögren's disease, retroperitoneal fibrosis and other fibrosing conditions, and may be a manifestation of a systemic fibro-inflammatory disorder.

CONCLUSION

Autoimmune pancreatocholangitis is a distinct inflammatory disorder involving the pancreas and biliary tree. The disease may mimick pancreatic carcinoma and PSC and responds to immunosuppressives.

Prevalence and distribution of extrapancreatic lesions complicating autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by high serum IgG4 concentrations and abundant IgG4-bearing plasma cell infiltration in the pancreatic lesion, and it has been reported to be associated with a variety of extrapancreatic lesions, leading us to postulate the concept of a systemic inflammatory disease. To confirm this, we clarified the exact distribution of these extrapancreatic lesions and provide a panoramic view of them.

METHODS

The frequency, distribution, clinical characteristics, and pathology of five extrapancreatic lesions were determined in 64 patients with autoimmune pancreatitis by examining clinical and laboratory findings.

RESULTS

The most frequent extrapancreatic lesion was hilar lymphadenopathy (80.4%), followed by extrapancreatic bile duct lesions (73.9%), lachrymal and salivary gland lesions (39.1%), hypothyroidism (22.2%), and retroperitoneal fibrosis (12.5%). No patients had all five types of lesions. Patients with hilar lymphadenopathy or lachrymal and salivary gland lesions were found to have significantly higher IgG4 levels than those without (P = 0.0042 and 0.0227, respectively). Patients with three lesions were found to have significantly higher IgG4 levels than those with no lesion, suggesting that patients with multiple extrapancreatic lesions have active disease. Similar to pancreatic lesions, extrapancreatic lesions have a characteristic histological finding of abundant IgG4-bearing plasma cell infiltration, and they respond favorably to corticosteroid therapy.

CONCLUSIONS

Autoimmune pancreatitis was recognized as a systemic inflammatory disease. Furthermore, recognition of these characteristic findings will aid in the correct diagnosis of this disease.

Autoimmune pancreatitis with IgG4-positive plasma cell infiltration in salivary glands and biliary tract

A 62-year-old male was referred to our hospital because of liver dysfunction, diffuse pancreatic swelling, and trachelophyma. At admission, the patient was free of pain. Physical examination showed enlarged and palpable bilateral submandibular masses, but no palpable mass or organomegaly in the abdomen. Laboratory findings were as follows: total protein 90 g/L with γ-globulin of 37.3% (33 g/L), total bilirubin 4 mg/L, aspartate aminotransferase 39 IU/L, alanine aminotransferase 67 IU/L, γ-glutamyl transpeptidase 1 647 IU/L, and amylase 135 IU/L. Autoanti-bodies were negative, and tumor markers were within the normal range. Serum IgG4 level was markedly elevated (18 900 mg/L). Computed tomography (CT) showed diffuse swelling of the pancreas and dilatation of both common and intra-hepatic bile ducts. Endoscopic retrograde pancreatography (ERP) revealed diffuse irregular and narrow main pancreatic duct and stenosis of the lower common bile duct. Biopsy specimens from the pancreas, salivary gland and liver showed marked periductal IgG4-positive plasma cell infiltration with fibrosis. We considered this patient to be autoimmune pancreatitis (AIP) with fibrosclerosis of the salivary gland and biliary tract, prescribed prednisolone at an initial dose of 40 mg/d. Three months later, the laboratory data improved almost to normal. Abdominal CT reflected prominent improvement in the pancreatic lesion. Swelling of the salivary gland also improved. At present, the patient is on 10 mg/d of prednisolone without recurrence of the pancreatitis. We present here a case of AIP with fibrosclerosis of salivary gland and biliary tract.

Autoimmune pancreatitis

The list of diseases associated with autoantibodies against tissues, cells, or specific autoantigens is growing, and many organs in the body are known to be affected by autoimmune injury. Until recently, the most well-known pancreatic autoimmune disorder was type 1 diabetes mellitus, where there is selective destruction of beta cells in the islets of Langerhans. Although an autoimmune process affecting the exocrine pancreas was suspected over four decades ago, it is only in the past 10 years or so that autoimmune chronic pancreatitis has been recognized as a distinct entity. Here we review the clinical, serologic, radiologic, and histologic features of autoimmune pancreatitis.

Distinct clinicopathological entity 'autoimmune pancreatitis-associated sclerosing cholangitis'

Autoimmune pancreatitis (AIP) is a recently proposed disease entity, in which an elevated serum IgG4 is characteristic. This disease is sometimes associated with other inflammatory diseases: Sjögren's disease, or sclerosing cholangitis. The aim of the present paper was to examine the difference in pathophysiology between AIP-associated sclerosing cholangitis (AIP-SC) and primary sclerosing cholangitis (PSC). The clinicopathological findings and the immunohistochemical expressions of IgG subclasses (IgG1, IgG2, IgG3, and IgG4) were evaluated for the two aforementioned diseases (six patients with each disease). Radiologically, the extrahepatic bile duct was involved in AIP-SC, whereas both extrahepatic and intrahepatic bile ducts were involved in PSC. Clinically, bile duct lesions in the former responded well to steroid therapy. Histologically, various degrees of mononuclear cell infiltration and fibrosis around bile ducts and portal tracts were found in all patients. Immunohistochemically, the IgG4-positive plasma cell/mononuclear cell ratio was significantly higher in AIP-SC than in PSC (P < 0.05). The IgG4-positive plasma cell/mononuclear cell ratio is a useful index to help distinguish AIP-SC from PSC. A mechanism similar to that involved in AIP may be involved in AIP-SC. The latter is a distinct clinicopathological entity that should be distinguished from PSC because it responds well to steroid therapy.

Immunoglobulin G4-related lymphoplasmacytic sclerosing cholangitis that mimics infiltrating hilar cholangiocarcinoma: part of a spectrum of autoimmune pancreatitis?

BACKGROUND

Autoimmune pancreatitis has been designated as sclerosing pancreatocholangitis, because this disease shows a high prevalence of bile-duct lesions. We present herein the clinical characteristics of unusual cases that show dominant bile-duct lesions and mimicking infiltrating hilar cholangiocarcinomas.

METHODS

Clinical and pathologic findings of 3 patients with immunoglobulin (Ig) G4 related sclerosing cholangitis who had no apparent pancreatic lesions comparable with autoimmune pancreatitis were analyzed.

OBSERVATIONS

All patients were middle-aged or elderly individuals with slightly elevated serum IgG4 concentrations and showed long-segment narrowing of the bile-duct system, mimicking infiltrating hilar cholangiocarcinoma without significant pancreatic change. The first patient was treated with a corticosteroid, resulting in amelioration of the narrowing of the bile duct. The second patient underwent surgery based on a diagnosis of cholangiocarcinoma. In the third patient, the bile-duct stricture reversed spontaneously 1 month after the drainage procedure. Pathologic findings of the bile ducts for all patients disclosed significant lymphoplasmacytic infiltration, including abundant IgG4-bearing plasma cells.

CONCLUSIONS

The use of IgG4 immunostaining in biopsy specimens of the bile duct may identify the presence of corticosteroid-responsive lymphoplasmacytic sclerosing cholangitis.

Treating patients with autoimmune pancreatitis: results from a long-term follow-up study

BACKGROUND

Steroid therapy is currently common treatment for autoimmune pancreatitis (AIP); however, indications of steroid therapy have yet to be established, and the clinical course after steroid therapy is unknown.

METHODS

A total of 23 patients with AIP were subdivided into 4 groups according to the initial treatments undertaken. They were treated with pancreatoduodenectomy on suspicion of pancreatic tumor in 6 patients, choledochoduodenostomy with pancreatic biopsy in 4 patients, supportive therapy in 3 patients, and steroid therapy in 10 patients. Clinical course of AIP in each group was examined.

RESULTS

Prognosis of the AIP patients is almost good except for the 2 patients who progressed to pancreatic insufficiency after resection. Two patients without jaundice improved spontaneously. Steroid therapy was effective in all patients treated, but pancreatic atrophy developed in 5 of these patients. Steroid therapy improved insulin secretion and glycemic control in 4 of 7 diabetes mellitus (DM) patients.

CONCLUSION

To avoid futile surgery, in relatively elderly male patients with obstructive jaundice suggestive of pancreatic carcinoma, preoperative clinical suspicion of AIP is mandatory. Indications of steroid therapy for AIP are thought to be obstructive jaundice due to stenosis of the bile duct, other associated systemic autoimmune, and DM coincidental with AIP.

Cholangiography can discriminate sclerosing cholangitis with autoimmune pancreatitis from primary sclerosing cholangitis

BACKGROUND

Sclerosing cholangitis with autoimmune pancreatitis has a cholangiographic appearance that is similar to that of primary sclerosing cholangitis, but only the former responds well to corticosteroid therapy. It, therefore, is necessary to distinguish between these two diseases. Cholangiography is the reference standard for the diagnosis of primary sclerosing cholangitis. The present study compared the characteristic findings for these two types of sclerosing cholangitis.

METHODS

Cholangiograms from patients with primary sclerosing cholangitis (n = 29) and sclerosing cholangitis with autoimmune pancreatitis (n = 26) were studied with regard to length and region of stricture formation, and other characteristic findings.

RESULTS

Band-like stricture, beaded or pruned-tree appearance, and diverticulum-like formation were significantly more frequent in primary sclerosing cholangitis. In contrast, segmental stricture, long stricture with prestenotic dilatation and stricture of the distal common bile duct were significantly more common in sclerosing cholangitis with autoimmune pancreatitis. Discriminant analysis based on these findings correctly identified 27 of 28 patients with primary sclerosing cholangitis and 25 of 26 patients with sclerosing cholangitis with autoimmune pancreatitis. It also identified a patient with an incorrect diagnosis of primary sclerosing cholangitis who proved, on review of a surgical specimen, to have findings consistent with lymphoplasmacytic sclerosing cholangitis.

CONCLUSIONS

Characteristic cholangiographic features allow discrimination of sclerosing cholangitis with autoimmune pancreatitis and lymphoplasmacytic sclerosing cholangitis without pancreatitis from primary sclerosing cholangitis.

Pancreatic mass lesions associated with raised concentration of IgG4

Autoimmune pancreatitis (AIP) is a recognized benign disease characterized by irregular narrowing of the pancreatic duct, swelling of parenchyma, lymphoplasmacytic infiltration and fibrosis, and a favorable response to corticosteroid treatment. In this condition, the whole pancreas is diffusely affected. Recently, however, a few cases with locally affected lesions were reported, with some of them showing features similar to cancer. We reviewed 138 patients with pancreatic mass lesion, of which 17 were not initially diagnosed despite examinations. Serum IgG4 levels were elevated in seven of them. Their biopsy specimens had a similar appearance to those of AIP. We considered that they should be diagnosed as AIP or conditions related to AIP. Among the 10 patients without elevated IgG4, 4 patients were diagnosed as pancreatic cancer after follow-up, 1 presented with an islet cell tumor, 1 presented AIP with sclerosing cholangitis, and the other 4 had chronic pancreatitis.

Autoimmune pancreatitis: imaging features

PURPOSE

To retrospectively determine imaging findings in patients with autoimmune pancreatitis.

MATERIALS AND METHODS

Twenty-nine patients (25 male and four female; mean age, 56 years; range, 15-82 years) with histopathologic diagnosis of autoimmune pancreatitis were examined. Data were reviewed by two radiologists in consensus. Imaging findings for review included those from helical computed tomography (CT), 25 patients; magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP), four patients; endoscopic ultrasonography (US), 21 patients; endoscopic retrograde cholangiopancreatography (ERCP), 19 patients; and percutaneous transhepatic cholangiography, one patient. Images were analyzed for appearances of pancreas, biliary and pancreatic ducts, and other findings, such as peripancreatic inflammation, encasement of vessels, mass effect, pancreatic calcification, peripancreatic nodes, and peripancreatic fluid collection. Follow-up images were available in nine patients. Serologic markers such as serum immunoglobulin G (IgG) and antinuclear antibody levels were available in 12 patients.

RESULTS

CT showed diffuse (n = 14) and focal (n = 7) enlargement of pancreas. Seven patients had minimal peripancreatic stranding, with lack of vascular encasement, calcification, or peripancreatic fluid collection. Nine patients had enlarged peripancreatic lymph nodes. MR imaging showed focal (n = 2) and diffuse (n = 2) enlargement with rimlike enhancement in one. MRCP revealed pancreatic duct strictures in two and sclerosing cholangitis-like appearance in one. Endoscopic US showed diffuse enlargement of pancreas with altered echotexture in 13 patients and focal mass in the head in six. ERCP showed stricture of distal common bile duct in 12 patients, irregular narrowing of intrahepatic ducts in six, diffuse irregular narrowing of pancreatic duct in nine, and focal stricture of proximal pancreatic duct in six. Serologic markers showed increased IgG and antinuclear antibody levels in seven of 12 patients. At follow-up, CT abnormalities and common bile duct strictures resolved after steroid therapy in three patients.

CONCLUSION

Features that suggest autoimmune pancreatitis include focal or diffuse pancreatic enlargement, with minimal peripancreatic inflammation and absence of vascular encasement or calcification at CT and endoscopic US, and diffuse irregular narrowing of main pancreatic duct, with associated multiple biliary strictures at ERCP.

Acute tubulointerstitial nephritis associated with autoimmune-related pancreatitis

Various etiologic factors have been identified in tubulointerstitial nephritis (TIN), including allergic drug reaction, infection, and immune-mediated disease. Immune-mediated TIN without significant glomerular involvement has been reported to occur as a renal complication secondary to Sjögren's syndrome, lupus nephritis, and antitubular basement membrane antibody-related disease. We present a first case of acute TIN associated with autoimmune-related pancreatitis (AIP). A 64-year-old man was referred to our division from a surgeon for the close examination of renal dysfunction. The pancreatic and biliary imaging showed segmental narrowing of the pancreatic duct with localized swelling of the pancreatic head, suggesting the carcinoma of the pancreatic head at that time. However, the laboratory findings also showed renal dysfunction with high level of serum immunoglobulin G and hypocomplementemia. Renal biopsy was performed to investigate the etiology of the renal dysfunction. The renal biopsy specimen showed acute TIN. The patient had no drug history, which may cause TIN. Oral corticosteroid therapy improved the renal function as well as histological damage, the pancreatic imaging study, and the laboratory tests of pancreatic and hepatobiliary enzyme. Although the pancreatic biopsy has not performed in our patient, his clinical course confirmed us that AIP was the final diagnosis for his pancreatic lesion. Despite further examination, there was no evidence of other autoimmune-related diseases such as Sjögren's syndrome. To our knowledge, this is the first report of acute TIN associated with AIP. We suggest that AIP may be an etiologic factor in some cases of TIN.

T cell lymphoplasmacellular and eosinophilic infiltration of the pancreas with involvement of the gallbladder and duodenum in non-alcoholic duct-destructive chronic pancreatitis

BACKGROUND

Non-alcoholic duct destructive chronic pancreatitis is a rare entity with specific pathological features. The majority of the patients are from Japan. We report a case with involvement of the distal bile duct, the gallbladder, the duodenum and the ampulla, and present a review of patients from Europe and the USA since 1997.

CASE PRESENTATION

A 56-year-old man presented with a 3-month history of mild acute pancreatitis and obstructive jaundice, followed by increasing weight loss, lethargy and epigastric pain. CT showed a mass in the head of the pancreas. ERCP demonstrated a smooth stricture of the intra-pancreatic main bile duct and an irregular, incomplete, stricture in the main pancreatic duct. A pancreatic cancer could not be reliably excluded, and, therefore, he underwent a pylorus-preserving Kausch-Whipple's pancreatoduodenectomy.

RESULTS

Histopathology showed typical peri-ductal T cell-rich lymphoplasmacellular and eosinophilic infiltration of the pancreas, with involvement of the distal bile duct but, also, unusual inflammatory infiltration of the gallbladder, the duodenum and the ampulla.

CONCLUSION

The inflammatory process in non-alcoholic duct-destructive chronic pancreatitis can affect the entire pancreato-biliary region and mimics pancreatic cancer. Currently, there are no definitive criteria for pre-operative diagnosis, so it is very difficult for one to avoid resection.