Idiopathic Duct-centric Pancreatitis Research Articles

Diagnostic value of imaging examination in autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) is a special type of chronic pancreatitis mediated by autoimmunity factors. It can be divided into two categories according to pathological characteristics: Lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric pancreatitis. In the clinical setting, the imaging manifestations of some AIP cases are atypical, so it is difficult to distinguish it from general pancreatitis, pancreatic ductal adenocarcinoma, lymphoma, and other malignant disorders. Most importantly, the treatment for and prognosis of these diseases are different. Therefore, a timely correct imaging diagnosis of AIP is key for AIP patients. After that, clinicians can take appropriate treatment measures for those patients, which is helpful for the prognosis of AIP.

Autoimmune pancreatitis: Current perspectives.

Over the last two decades, our knowledge and understanding regarding the pathogenesis and biology of autoimmune pancreatitis (AIP) have improved tremendously. Type 1 AIP or IgG4-related pancreatitis (IgG4-RP) is now believed to be the prototype of the multisystemic IgG4-related disease. In view of clinical features like obstructive jaundice and mass-forming lesions in the pancreas in elderly men, type 1 AIP often mimics pancreatic cancer. IgG4-related sclerosing cholangitis concomitantly involving the extrahepatic and intrahepatic biliary tree is the most common extrapancreatic involvement seen in up to 80% of these patients, which needs to distinguish from cholangiocarcinoma. Histology is characterised by lymphoplasmacytic inflammation, abundant IgG4 positive plasma cell infiltration, storiform fibrosis and obliterative phlebitis. Apart from histology, high serum IgG4 levels, pancreatic parenchymal and duct imaging findings and other organ involvement aid in diagnosis especially in cases where definitive histology is not evident. Also, these parameters lay the foundation of various diagnostic criteria proposed over last few years. On the contrary, histology alone is the mainstay for establishing diagnosis of idiopathic duct-centric pancreatitis (IDCP) as it lacks any specific serological marker or imaging. Since both types of AIP respond dramatically to corticosteroid treatment, a biopsy is crucial to establish the preoperative diagnosis and to exclude malignancy so as to avoid unnecessary surgery. This review discusses the morphologic spectrum, treatment and prognosis of IgG4-RP and IDCP with an emphasis on approach to diagnosis with relevant histologic features, differential diagnoses and the challenges faced during biopsy interpretation.

Cardiovascular and lung involvement in patients with autoimmune pancreatitis

Introduction: Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated disease characterised pathologically by the infiltration of IgG4-bearing plasma cells into the involved organs. Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis with a heavy lymphocytic infiltration and two distinct histopathological subtypes, namely: lymphoplasmacytic sclerosing pancreatitis (AIP type 1) and idiopathic duct-centric pancreatitis (AIP type 2). Lung involvement and aortic involvement have been reported in 12% and 9% of patients with systemic IgG4-RD, respectively. In series including patients with AIP, both lung and aortic involvement were described in 2% of the patients. Most of the epidemiological data come from Japan, and there is a lack of information from Europe, especially the Scandinavian countries. Patients and methods: We performed a single-centre retrospective study on a prospectively collected cohort of patients diagnosed with AIP at the Department for Digestive Diseases at Karolinska University Hospital in Stockholm, Sweden, from 2004 to 2019. Demographic and clinical data were collected from the medical charts. Results: One hundred and thirty-three patients with AIP were analysed. Six patients were excluded because they lacked some of the clinical data relevant to the study. Demographic and clinical features of 127 patients were presented. There were 98 patients with AIP type 1-35 (35.7%) female and 63 (64.3%) male, with a mean age of 55.4 ± 18.2. Among them, 15 (15.3%) patients had lung and/or cardiovascular involvement-11 (11.2%) patients had lung involvement, 10 (10.2%) patients had cardiovascular involvement (six patients had both). Most of them (67.0%) had never smoked. The mean follow-up time of the patients with AIP type 1 was 49 months. Conclusions: Lung and/or cardiovascular involvement were diagnosed in 15 (15.3%) patients in our historical cohort of patients with AIP type 1. Most of the lung involvement was presented in the form of nodular lesions in the lungs, non-specific infiltrates, “ground-glass” appearance with pleura thickening, and effusion. Aortic involvement was a major form of vascular involvement in patients with AIP, as in previous published studies on patients with IgG4-RD.

Management of autoimmune pancreatitis

The article contains modern data on such a chronic pancreatic disease as autoimmune pancreatitis (AIP). Statistical data on the prevalence and incidence of AIP are presented, the current international classification of this pathology is considered, the main features of type 1 AIP (lymphoplasmacytic sclerosing pancreatitis, LPSP) and type 2 AIP (idiopathic duct centric pancreatitis, IDCP) are put forward. The clinical manifestation of these types is different: obstructive jaundice develops more often in patients with LPSP, while patients with IDCP mostly have acute pancreatitis. The presence and variety of extrapancreatic manifestations of the disease with extremely frequent concomitant development of ulcerative colitis is emphasized. The features of serological diagnosis of AIP and the role of IgG4 level in determining the type of disease are considered. The proper techniques of AIP instrumental diagnostics are listed, the typical changes detected during computed tomography and the distinctive histological characteristics of LPSP and IDCP are considered. The feasibility of a differential diagnosis between AIP and pancreatic cancer is indicated by analyzing the results of serological, imaging, and histological studies. The algorithm of management of AIP patients depending on the type of disease is described, as well as the tactics of prescribing corticosteroids, immunomodulators upon LPSP and IDCP. Immunomodulators of choice (mycophenolate mofetil, azathioprine) are indicated, and rituximab administration features are considered. Possible signs of AI recurrence are listed (IgG4-sclerosing cholangitis, high IgE level).

Immunoglobulin G subtypes-1 and 2 differentiate immunoglobulin G4-associated sclerosing cholangitis from primary sclerosing cholangitis.

BackgroundAutoimmune pancreatitis is a special form of chronic pancreatitis with strong lymphocytic infiltration and two histopathological distinct subtypes, a lymphoplasmacytic sclerosing pancreatitis and idiopathic duct centric pancreatitis. Immunoglobulin G4-associated cholangitis may be present at the time of autoimmune pancreatitis type 1 diagnosis or occur later over the course of the disease. Immunoglobulin G4 is considered reliable but not an ideal marker for diagnosis of autoimmune pancreatitis type 1 with reported sensitivity between 71–81%. It is essential to differentiate sclerosing cholangitis with autoimmune pancreatitis from primary sclerosing cholangitis as the treatment and prognosis of the two diseases are totally different. It was the aim of the study to find a marker for immunoglobulin G4-associated cholangitis that would distinguish it from primary sclerosing cholangitis.Patients and methodsWe performed a retrospective analysis of patients with autoimmune pancreatitis at our outpatient clinic. Patients from the primary sclerosing cholangitis registry were taken as a control group. Blood samples for the measurement of immunoglobulin subclasses were analysed at the time of diagnosis.ResultsPatients with autoimmune pancreatitis and immunoglobulin G4-associated cholangitis had higher values of immunoglobulin G2 when compared to autoimmune pancreatitis alone or primary sclerosing cholangitis with a high specificity (97%) and high positive predictive value (91%). In patients with normal or low immunoglobulin G2 or immunoglobulin G4, a high level of immunoglobulin G1 indicated primary sclerosing cholangitis.ConclusionImmunoglobulin G1 and immunoglobulin G2 can distinguish patients with immunoglobulin G4-associated cholangitis from those with primary sclerosing cholangitis.

Cardiovascular and Lung Involvement in Patients with Autoimmune Pancreatitis

Introduction: Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated disease characterised pathologically by the infiltration of IgG4-bearing plasma cells into the involved organs. Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis with a heavy lymphocytic infiltration and two distinct histopathological subtypes, namely: lymphoplasmacytic sclerosing pancreatitis (AIP type 1) and idiopathic duct-centric pancreatitis (AIP type 2). Lung involvement and aortic involvement have been reported in 12% and 9% of patients with systemic IgG4-RD, respectively. In series including patients with AIP, both lung and aortic involvement were described in 2% of the patients. Most of the epidemiological data come from Japan, and there is a lack of information from Europe, especially the Scandinavian countries. Patients and methods: We performed a single-centre retrospective study on a prospectively collected cohort of patients diagnosed with AIP at the Department for Digestive Diseases at Karolinska University Hospital in Stockholm, Sweden, from 2004 to 2019. Demographic and clinical data were collected from the medical charts. Results: One hundred and thirty-three patients with AIP were analysed. Six patients were excluded because they lacked some of the clinical data relevant to the study. Demographic and clinical features of 127 patients were presented. There were 98 patients with AIP type 1-35 (35.7%) female and 63 (64.3%) male, with a mean age of 55.4 ± 18.2. Among them, 15 (15.3%) patients had lung and/or cardiovascular involvement-11 (11.2%) patients had lung involvement, 10 (10.2%) patients had cardiovascular involvement (six patients had both). Most of them (67.0%) had never smoked. The mean follow-up time of the patients with AIP type 1 was 49 months. Conclusions: Lung and/or cardiovascular involvement were diagnosed in 15 (15.3%) patients in our historical cohort of patients with AIP type 1. Most of the lung involvement was presented in the form of nodular lesions in the lungs, non-specific infiltrates, “ground-glass” appearance with pleura thickening, and effusion. Aortic involvement was a major form of vascular involvement in patients with AIP, as in previous published studies on patients with IgG4-RD.

Steroid Therapy and Steroid Response in Autoimmune Pancreatitis.

Autoimmune pancreatitis (AIP), a unique subtype of pancreatitis, is often accompanied by systemic inflammatory disorders. AIP is classified into two distinct subtypes on the basis of the histological subtype: immunoglobulin G4 (IgG4)-related lymphoplasmacytic sclerosing pancreatitis (type 1) and idiopathic duct-centric pancreatitis (type 2). Type 1 AIP is often accompanied by systemic lesions, biliary strictures, hepatic inflammatory pseudotumors, interstitial pneumonia and nephritis, dacryoadenitis, and sialadenitis. Type 2 AIP is associated with inflammatory bowel diseases in approximately 30% of cases. Standard therapy for AIP is oral corticosteroid administration. Steroid treatment is generally indicated for symptomatic cases and is exceptionally applied for cases with diagnostic difficulty (diagnostic steroid trial) after a negative workup for malignancy. More than 90% of patients respond to steroid treatment within 1 month, and most within 2 weeks. The steroid response can be confirmed on clinical images (computed tomography, ultrasonography, endoscopic ultrasonography, magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography). Hence, the steroid response is included as an optional diagnostic item of AIP. Steroid treatment results in normalization of serological markers, including IgG4. Short- and long-term corticosteroid treatment may induce adverse events, including chronic glycometabolism, obesity, an immunocompromised status against infection, cataracts, glaucoma, osteoporosis, and myopathy. AIP is common in old age and is often associated with diabetes mellitus (33–78%). Thus, there is an argument for corticosteroid therapy in diabetes patients with no symptoms. With low-dose steroid treatment or treatment withdrawal, there is a high incidence of AIP recurrence (24–52%). Therefore, there is a need for long-term steroid maintenance therapy and/or steroid-sparing agents (immunomodulators and rituximab). Corticosteroids play a critical role in the diagnosis and treatment of AIP.

The Challenge of Autoimmune Pancreatitis: A Portrayal From the Pediatric Perspective.

Autoimmune pancreatitis (AIP) is a rare disorder characterized by prompt clinical response to corticosteroids. Lost tolerance to a variety of pancreatic antigens and subsequent development of autoantibodies are presumably involved in the initiation of AIP. Even pediatric patients have been reported with features of AIP, and awareness of this disorder is increasing among different clinicians. The terms lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric pancreatitis refer to the different histologic patterns of AIP, named type 1 and type 2, respectively. A combination of serologic, radiologic, and histologic investigations is needed to assess diagnosis of AIP and rule out neoplastic disorders. In addition, type 1 AIP can be distinguished by raised levels of serum immunoglobulin G4 and should be considered as part of systemic immunoglobulin G4-related disease. Conversely, type 2 AIP is frequently reported in younger patients and has less clear immune-mediated pathogenetic mechanisms. The natural history of pediatric AIP is obscure, and the diagnostic usefulness of different autoimmune abnormalities found in adults with AIP is limited for children. Tips to manage pediatric patients with AIP have been recently drafted through a set of recommendation statements. This review describes the current data about AIP and the pathogenic contribution of specific autoantibodies expressly in the pediatric population.

Management of Autoimmune Pancreatitis

The article contains modern data on such a chronic pancreatic disease as autoimmune pancreatitis (AIP). Statistical data on the prevalence and incidence of AIP are presented, the current international classification of this pathology is considered, the main features of type 1 AIP (lymphoplasmacytic sclerosing pancreatitis, LPSP) and type 2 AIP (idiopathic duct centric pancreatitis, IDCP) are put forward. The clinical manifestation of these types is different: obstructive jaundice develops more often in patients with LPSP, while patients with IDCP mostly have acute pancreatitis. The presence and variety of extrapancreatic manifestations of the disease with extremely frequent concomitant development of ulcerative colitis is emphasized. The features of serological diagnosis of AIP and the role of IgG4 level in determining the type of disease are considered. The proper techniques of AIP instrumental diagnostics are listed, the typical changes detected during computed tomography and the distinctive histological characteristics of LPSP and IDCP are considered. The feasibility of a differential diagnosis between AIP and pancreatic cancer is indicated by analyzing the results of serological, imaging, and histological studies. The algorithm of management of AIP patients depending on the type of disease is described, as well as the tactics of prescribing corticosteroids, immunomodulators upon LPSP and IDCP. Immunomodulators of choice (mycophenolate mofetil, azathioprine) are indicated, and rituximab administration features are considered. Possible signs of AI recurrence are listed (IgG4-sclerosing cholangitis, high IgE level).

Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a subcategory of chronic pancreatitis that is highly responsive to steroids. The term was first proposed in 1995 by Yoshida and colleagues, and since its discovery, the diagnosis of AIP has dramatically increased. AIP is a chronic fibroinflammatory disease characterized by lymphoplasmacytic infiltrates and fibrosis on histology. There are two distinct subtypes: type 1 AIP is the pancreatic manifestation of a systemic serum immunoglobulin G subtype 4–related disease (IgG4-RD) and type 2 AIP is described clinically as idiopathic duct-centric pancreatitis and has no association with IgG4. Clinically, AIP presents most commonly as obstructive jaundice in type 1 AIP and can present as acute pancreatitis in type 2 AIP. The diagnostic criteria include histology, imaging findings, and responsiveness to steroids as well as laboratory findings and other organ involvement. The mainstay of treatment is steroid therapy, with immunomodulators such as rituximab used for maintenance or relapsing disease. Long-term complications of AIP include pancreatic insufficiency and are often associated with relapsing disease. This review contains 45 references, 1 figure, and 2 tables. Key Words: autoimmune pancreatitis, chronic pancreatitis, EUS-guided biopsy, IgG4, immunomodulatory, obstructive jaundice, pancreas mass, steroid

Autoimmune Pancreatitis.

Autoimmune pancreatitis (AIP) is a chronic fibroinflammatory disease of the pancreas that belongs to the spectrum of immunoglobulin G-subclass4-related diseases (IgG4-RD) and typically presents with obstructive jaundice. Idiopathic duct-centric pancreatitis (IDCP) is a closely related but distinct disease that mimics AIP radiologically but manifests clinically most commonly as recurrent acute pancreatitis in young individuals with concurrent inflammatory bowel disease. IgG4 levels are often elevated in AIP and normal in IDCP. Histologically, lymphoplasmacytic acinar inflammation and storiform fibrosis are seen in both. In addition, the histologic hallmark of IDCP is the granulocyte epithelial lesion: intraluminal and intraepithelial neutrophils in medium-sized and small ducts with or without granulocytic acinar inflammation often associated with destruction of ductal architecture. Initial treatment of both AIP and IDCP is with oral corticosteroids for duration of 4weeks followed by a gradual taper. Relapses are common in AIP and relatively uncommon in IDCP, a relatively rare disease for which the natural history is not well understood. For patients with relapsing AIP, treatment with immunomodulators and more recently rituximab has been recommended. Although rare instances of pancreaticobiliary malignancy has been reported in patients with AIP, overall the lifetime risk of developing pancreatic cancer does not appear to be elevated.

From Pathogenesis, Clinical Manifestation, and Diagnosis to Treatment: An Overview on Autoimmune Pancreatitis.

Autoimmune pancreatitis (AIP) is a special type of chronic pancreatitis which is autoimmune mediated. The international consensus diagnostic criteria (ICDC) 2011 proposed two types of AIP: type I is associated with histological pattern of lymphoplasmacytic sclerosing pancreatitis (LPSP), characterized by serum IgG4 elevation, whereas type 2 is named idiopathic duct-centric pancreatitis (IDCP), with granulocytic epithelial lesion (GEL) and immunoglobulin G4 (IgG4) negative. The pathogenic mechanism is unclear now; based on genetic factors, disease specific or related antigens, innate and adaptive immunity may be involved. The most common clinical manifestations of AIP are obstructive jaundice and upper abdominal pain. The diagnosis can be made by a combination of parenchymal and ductal imaging, serum IgG4 concentrations, pancreatic histology, extrapancreatic disease, and glucocorticoid responsiveness according to ICDC 2011. Because of the clinical and imaging similarities with pancreatic cancer, general work-up should be done carefully to exclude pancreatic malignant tumor before empirical trial of glucocorticoid treatment. Glucocorticoid is the most common drug for AIP to induce remission, while there still exists controversy on steroid maintenance and treatment for relapse. Further studies should be done to identify more specific serum biomarkers for AIP, the pathogenic mechanisms, and the treatment for relapse.

Autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) is a rare, distinct and increasingly recognized form of pancreatitis which has autoimmune features. The international consensus diagnostic criteria (ICDC) for AIP recently described two subtypes; type 1[lymphoplasmacytic sclerosing pancreatitis (LPSP)] and type 2 [idiopathic duct-centric pancreatitis (IDCP) or AIP with granulocytic epithelial lesion (GEL)]. Type 1 is the more common form of the disease worldwide and current understanding suggests that it is a pancreatic manifestation of immunoglobulin G4-related disease (IgG4-RD). In contrast, type 2 AIP is a pancreas-specific disease not associated with IgG4 and mostly without the overt extra-pancreatic organ involvement seen in type 1. The pathogenesis of AIP is not completely understood and its clinical presentation is non-specific. It shares overlapping features with more sinister pathologies such as cancer of the pancreas, which continues to pose a diagnostic challenge for clinicians. The diagnostic criteria requires a variable combination of histopathological, imaging and serological features in the presence of typical extrapancreatic lesions and a predictable response to steroids.

Autoimmune pancreatitis and inflammatory bowel disease: Case series and review of the literature

BackgroundAn association between autoimmune pancreatitis (AIP) and inflammatory bowel disease (IBD) has been documented, but its clinical significance remains unclear. AimsCharacterize the particular phenotypes of IBD and AIP in patients with both diseases (IBD-AIP). MethodsRetrospective study of patients with IBD-AIP followed at our IBD referral centre and literature search to identify previous reports of IBD-AIP patients. ResultsWe found 5 cases of IBD-AIP in our records and 5 prior studies reporting 47 additional IBD-AIP patients. A combined analysis showed that most IBD-AIP patients were young males with ulcerative colitis, usually extensive, and that in all Crohn's disease cases, the colon was involved. IBD severity was heterogeneous across studies, ranging from mild disease to severe disease requiring colectomy. The most frequent type of AIP was idiopathic duct-centric pancreatitis (type 2) and it most often occurred after the diagnosis of IBD. AIP presentation and treatment were similar to those in the general population. ConclusionsAIP occurs rarely with IBD; in the other way around, up to 1/3 of AIP patients, especially type 2, may have concomitant IBD. IBD-AIP patients are usually males presenting extensive colitis. More data are needed on the impact of AIP, if any, in IBD course.

Autoimmune Pancreatitis: A Diagnostic Challenge for the Clinician.

Autoimmune pancreatitis (AIP) is a rare cause of chronic pancreatitis that poses a diagnostic challenge to the clinician in that it mimics pancreatic cancer and presents with painless obstructive jaundice. In this review, we discuss the two types of AIP: type 1, known as lymphoplasmacytic sclerosing pancreatitis and type 2, known as idiopathic duct centric pancreatitis. Type 1 AIP is considered as a pancreatic manifestation of immunoglobulin G4-related disease. The etiopathogenesis of AIP, particularly type 2 AIP, is largely unknown. Both types of AIP have unique pancreatic histological features; however, the radiological and clinical features may mimic those of pancreatic cancer. The most commonly used diagnostic criteria, including the Japan Pancreas Society criteria, the Mayo Clinic HISORt (histology, imaging serology, other organ involvement, and response to therapy) criteria, and the International Association of Pancreatology's international consensus diagnostic criteria, that help to differentiate AIP from pancreatic cancer are reviewed in this article. The treatment of choice for induction of remission for AIP is steroid therapy. Relapses are more common in type 1 AIP. In selected patients, immunomodulators such as azathioprine and rituximab are used to maintain remission.

Pancreatitis autoinmune

Autoimmune pancreatitis is a benign fibroinflammatory disease of the pancreas of probable autoimmune origin, which includes 2 different phenotypes: type 1 (lymphoplasmacytic sclerosing pancreatitis) and type 2 (idiopathic duct-centric pancreatitis). Its clinical presentation as obstructive jaundice in patients with a pancreatic mass is common and therefore it must be included in the differential diagnosis of pancreatic neoplasia. Many diagnostic criteria have been described throughout history. The most famous are the HISORT criteria of the Mayo Clinic and the international consensus criteria of 2011. One of the main features of autoimmune pancreatitis is its dramatic response to steroid therapy, without the need for surgical treatment. Knowledge of this disease can dramatically change the management of patients with obstructive jaundice, who would otherwise be subjected to a pancreaticoduodenectomy.

Comparison of neutrophil infiltration between type 1 and type 2 autoimmune pancreatitis

BackgroundCharacteristics of type 2 autoimmune pancreatitis (AIP) is granulocyte epithelial lesions, called idiopathic duct-centric pancreatitis (IDCP). To clarify pathogenesis of IDCP, we investigated mechanism of neutrophil infiltration in type 1 AIP, called lymphoplasmacytic sclerosing pancreatitis (LPSP) and IDCP. MethodThis study was performed on resected pancreata from patients with alcoholic chronic pancreatitis (ACP, n = 10), LPSP (n = 10) and IDCP (n = 12). The number of neutrophils around the pancreatic ducts was counted. The expression of neutrophils chemoattractants granulocyte chemotactic protein-2 (GCP-2) and interleukin-8 (IL-8) in the pancreatic duct epithelia was examined using immunohistochemistry. The cell staining intensity is scored as negative (0), weak (1), moderate (2) or strong (3). ResultsThe median number of neutrophils around the interlobular pancreatic ducts was significantly higher in IDCP (15.16; interquartile range [IQR]: 9.74–18.41) than in ACP (2.66; IQR: 1.33–4.33) (P < 0.05) and LPSP (3.16; IQR: 2.74–4.57) (P < 0.01). There was no significant difference in the median number of neutrophils around the intralobular pancreatic ducts among ACP (1.16; IQR: 0.33–3.41), LPSP (3.16; IQR: 0.74–5.5) and IDCP (3.00; IQR: 1.08–7.91). The median score of GCP-2 in the interlobular pancreatic duct epithelia was significantly higher in IDCP (1.5; IQR: 0.25–2) than in ACP (0; IQR: 0–0.75) (P < 0.05) and LPSP (0; IQR: 0–0.75) (P < 0.05). There was no significant difference in the median score of IL-8 in the interlobular pancreatic duct epithelia among ACP (0; IQR: 0–0.75), LPSP (1; IQR: 0–1.75) and IDCP (0.5; IQR: 0–1). ConclusionsSignificantly increased neutrophil infiltration around the interlobular pancreatic duct in IDCP may depend on GCP-2.

Autoimmune pancreatitis--treatment and pitfalls in diagnostics

Autoimmune pancreatitis (AIP) was first classified as a defined disease entity in 1995. It accounts for approximately 2 % of cases of chronic pancreatitis (western world prevalence 36-41/100,000 inhabitants) and AIP is diagnosed in 2.4 % of pancreas resection specimens. Presentation of strategies for diagnosis and treatment with focus on differentiation of AIP and pancreatic carcinoma. Selective literature research in PubMed regarding pathogenesis, diagnosis and treatment of AIP. Key characteristics of AIP are recurrent jaundice due to obstructed bile ducts, histological evidence of fibrosis, a lymphoplasmocytic or granulocytic infiltrate and the response to steroid therapy. There are two distinctive forms of AIP: type I or lymphoplasmocytic sclerosing pancreatitis and type II or idiopathic duct centric pancreatitis. The IgG4 positive AIP type I belongs to the group of IgG4-related systemic diseases. Diagnosis of AIP is established according to the international consensus diagnostic criteria (ICDC) or HISORt (mnemonic standing for histology, imaging, serology, other organ involvement and response to therapy) criteria. Differentiation from pancreatic adenocarcinoma can be challenging. The standard treatment consists of corticosteroids and in some cases azathioprine can be added. In refractory disease rituximab is a further option. Treatment is indicated in patients with jaundice, systemic manifestation or persistent pain. Although AIP is increasingly being identified, the differentiation from pancreatic adenocarcinoma still remains difficult and in cases of a suspicion of neoplasia, resection should be favored. It can successfully be treated conservatively with steroids and rituximab.

Multiple gene mutations in patients with type 2 autoimmune pancreatitis and its clinical features.

BackgroundIt is now clear that there are two histological types (type 1 and type 2) of autoimmune pancreatitis (AI P). The histological substance of type 1 AI P is known as lymphoplasmacytic sclerosing pancreatitis (LPSP) or traditional AIP, and type 2 AIP is characterized by distinct histology called idiopathic duct centric pancreatitis (IDCP). Serum IgG4 increase is considered as a marker for type 1 AI P. Far less is known about type 2 and it lacks predicting markers, so it easily leads to missed diagnosis and misdiagnosis.The aim of this studyThe aim of this study was to describe multi-gene mutations in patients with type 2 AI P and its clinical features.Material and methodsThree unrelated patients with type 2 AI P, 10 cases with type 1 AIP, 15 cases with other chronic pancreatitis and 120 healthy individuals were studied. The mutations and polymorphisms of 6 genes involved in chronic pancreatitis or pancreatic cancer — PRSS1, SPINK1, CFTR, MEN1, PKHD1, and mitochondrial DNA – were sequenced. Information of clinical data was collected by personal interview using a structured questionnaire.ResultsNovel mutations were found in the genes encoding for MEN1 (p.546 Ala > The) and PKHD1 (c. 233586 A > G and c. 316713 C > T) from patients with type 2 AIP. What is more, the serum TCR (T cell receptor) level is relatively higher in patients with type 2 AIP than in patients with type 1 AIP and other chronic pancreatitis or normal controls. Weight loss was the major manifestation and no patients had extrapancreatic involvement in type 2 AIP.ConclusionsType 2 AIP may occur with multi-gene mutations. For screening purposes, it is more reasonable to evaluate TCR levels in serum.

Pathophysiology of autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) is a recently discovered form of pancreatitis and represents one of the diseases of the pancreas which can be cured and healed medically. International consensus diagnostic criteria have been developed, and the clinical phenotypes associated with the histopathologic patterns of lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric pancreatitis should be referred to as type 1 and type 2 AIP, respectively. Most importantly, in type 1 AIP, the pancreatic manifestations are associated with other extrapancreatic disorders, resembling an immunoglobulin G4 (IgG4)-related disease. In addition, the pancreas of a patient with AIP is often infiltrated by various types of immune cells; the cluster of differentiation (CD) 4 or CD8 T lymphocytes and IgG4-bearing plasma cells have been found in the pancreatic parenchyma and other involved organs in AIP and factors regulating T-cell function may influence the development of AIP. From a genetic point of view, it has also been reported that DRB1*0405 and DQB1*0401 mutations are significantly more frequent in patients with AIP when compared to those with chronic calcifying pancreatitis, and that only DQB1*0302 had a significant association with the relapse of AIP. Finally, it has been found that the polymorphic genes encoding cytotoxic T lymphocyte-associated antigen 4, a key negative regulator of the T-cell immune response, are associated with AIP in a Chinese population. Even if these data are not concordant, it is possible that physiological IgG4 responses are induced by prolonged antigen exposure and controlled by type 2 helper T cells. We reviewed the current concepts regarding the pathophysiology of this intriguing disease, focusing on the importance of the humoral and cellular immune responses.