Autoimmune pancreatitis

Although the pathogenesis of autoimmune pancreatitis is unclear, recent evidence of clinical aspects are presented: (i) mild abdominal symptoms, usually without acute attacks of pancreatitis; (ii) occasional existence of obstructive jaundice; (iii) increased levels of serum gammaglobulin, IgG or IgG4; (iv) presence of autoantibodies; (v) diffuse enlargement of the pancreas; (vi) irregularly narrowing of the pancreatic duct (sclerosing pancreatitis) with often intra-pancreatic biliary stenosis or coexistence of biliary lesions (sclerosing cholangitis similar to primary sclerosing cholangitis: PSC) on endoscopic retrograde cholangiopancreatographic (ERCP) images; (vii) fibrotic changes with lymphocyte and IgG4-positive plasmacyte infiltration, and obliterative thrombo-phlebitis; (viii) occasional association with other systemic lesions such as sialoadenitis, retroperitoneal fibrosis, interstitial renal tubular disorders, and (ix) effective steroid therapy. In addition to pancreatic and extra-pancreatic lesions, diabetes mellitus is occasionally responsive to steroid therapy. Further studies are needed to clarify the pathogenesis.     

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.     

Autoimmune pancreatitis

Autoimmune pancreatitis is the pancreatic manifestation of a systemic disorder that affects various organs, including the bile duct, retroperitoneum, kidney, and parotid and lacrimal glands. It represents a recently described subset of chronic pancreatitis that is immune mediated and has unique histologic, morphologic, and clinical characteristics. A hallmark of the disease is its rapid response to corticosteroid treatment. Although still a rare disease, autoimmune pancreatitis is increasingly becoming recognized clinically, leading to evolution in the understanding of its prognosis, clinical characteristics, and treatment.     

Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a benign, IgG4-related, fibroinflammatory form of chronic pancreatitis that can mimic pancreatic ductal adenocarcinoma both clinically and radiographically. Laboratory studies typically demonstrate elevated serum IgG4 levels and imaging studies reveal a diffusely or focally enlarged pancreas with associated diffuse or focal narrowing of the pancreatic duct. The pathologic features include periductal lymphoplasmacytic inflammation, obliterative phlebitis, and abundant IgG4-positive plasma cells. The treatment of choice for AIP is steroid therapy. Diagnostic criteria for AIP have been proposed that incorporate histologic, radiographic, serologic, and clinical information.     

Autoimmune pancreatitis

Autoimmune pancreatitis is a rare systemic fibrotic inflammatory disorder that can affect organs such as the bile ducts, salivary glands, and retroperitoneal lymph nodes, in addition to the pancreas. Morphological characteristics of autoimmune pancreatitis include a diffusely enlarged 'sausage-shaped' pancreas and an irregularly narrowed duct of Wirsung. According to the revised Japan Pancreas Society criteria, the diagnosis of autoimmune pancreatitis requires that one or more secondary serologic or histologic criteria are also met: the presence of autoantibodies, elevated levels of gamma-globulins, IgG or IgG(4), a lymphoplasmacytic infiltrate, or pancreatic fibrosis. The presence in any affected organ of a lymphoplasmacytic inflammatory infiltrate containing greater than 10 IgG(4)-positive cells per high-power field is pathognomonic for autoimmune pancreatitis. Precise data on the incidence and prevalence of autoimmune pancreatitis are currently not available because most reports involve either limited patient series or resection specimen cohorts. New diagnostic tools and further studies of the underlying pathophysiology and prognosis of autoimmune pancreatitis are needed for adequate and effective treatment strategies to be developed. The most crucial issue when caring for patients with suspected autoimmune pancreatitis is to differentiate autoimmune pancreatitis from pancreatic carcinoma, because pancreatic carcinoma requires surgery, whereas autoimmune pancreatitis responds well to steroid treatment.     

Autoimmune pancreatitis

Abstract

Background. Autoimmune pancreatitis (AIP) is a relatively newly recognized type of pancreatitis that is characterized by diffuse or focal swelling of the pancreas due to lymphoplasmacytic infiltration and fibrosis of the pancreatic parenchyma. Material and methods. A PubMed literature search was performed using the keywords “autoimmune pancreatitis”. Sometimes, bibliographies were cross-referenced and related article searches were performed once an article of interest was identified. Results. Pathologically, AIP shows narrowing of the pancreatic ducts and the intrapancreatic portion of the common bile duct. Obstructive jaundice is a common symptom at presentation, and pancreatic cancer represents an important clinical differential diagnosis. In late stages of the disease, the normal pancreatic parenchyma is often replaced by large amounts of fibrosis. Histologically, there seem to be two subtypes of the disease–one showing infiltration with IgG4-positive plasma cells but lacking granulocytic epithelial lesions (GELs), the other showing GELs but lacking strong IgG4 positivity. AIP is in at least some instances the pancreatic manifestation of a clinicopathological entity of IgG4-related systemic sclerosing disease. On the basis of pancreatic imaging, together with serological measurement of IgG4 and evaluation of other organ involvement, many AIP patients can be identified. The remaining patients require further diagnostic work-up. In these patients, pancreatic core needle biopsy and, as AIP responds to steroid treatment, also a trial with steroids, can help to differentiate AIP from pancreatic cancer. Outlook and discussion. This review presents the pathological, radiologic and laboratory findings of AIP. Moreover, the treatment and pathogenesis are discussed.     

Autoimmune pancreatitis

Autoimmune pancreatitis is a type of idiopathic pancreatitis. It is also referred to as sclerosing pancreatitis, lymphoplasmatocytic sclerosing pancreatitis, chronic pancreatitis with irregular stenosis of the main pancreatic duct and as sclerosing pancreatocholangitis. Clinical characteristics of autoimmune pancreatitis are jaundice, abdominal pain, weight loss and diabetes mellitus. Radiologically, there is diffuse enlargement of pancreas with stenosis of pancreatic duct without calcifications in the pancreatic parenchyma. In autoimmune pancreatitis, antibodies against lactoferrin and carbonic anhydrase have been detected, but they are not specific because they are present in some other autoimmune diseases too. Also in autoimmune pancreatitis, there are increased levels of gammaglobulins and characteristically high titres of IgG4, which are a subtype of IgG. Autoimmune pancreatitis is usually treated successfully by prednisolone.     

自身免疫性胰腺炎

慢性胰腺炎是指由于胰腺实质反复或持续性炎症所导致的胰腺形态改变，伴有不同程度的胰腺内、外分泌功能障碍。既往认为其病因主要与急性胰腺炎或饮酒有关，近年米有研究发现Ⅱ类主要组织相容性复合物缺陷的人鼠可自发地发展为慢性胰腺炎，提示自身免疫可能也是其发病的原因之一并提出了自身免疫性胰腺炎概念。本文拟对此类胰腺炎的研究进展进行综述。     

Autoimmune pancreatitis

The purpose of this review is to provide a concise view of the existing knowledge of autoimmune pancreatitis (AIP) for practicing clinicians. AIP is a rare disease whose recognition and understanding are evolving. It is a type of chronic pancreatitis that often presents as obstructive jaundice, has a distinctive histology, and is exquisitely sensitive to steroid therapy. This form of chronic pancreatitis has a unique clinical, biochemical, and radiological profile. The term "AIP" encompasses two subtypes: types 1 and 2. Type 1 AIP is the pancreatic manifestation of a systemic fibro-inflammatory disease called immunoglobulin G4-associated systemic diseases. Type 2 AIP has been shown to be associated with inflammatory bowel disease. Existing criteria are geared towards the diagnosis of type 1 AIP. At present, pancreatic histology is a requirement for the definitive diagnosis of type 2 AIP. AIP can mimic most other pancreatic diseases in its presentation, but in clinical practice, it often has to be differentiated from pancreatic cancer. There are established criteria and algorithms not only to diagnose AIP, but also to differentiate it from pancreatic cancer. The utility of these algorithms and the approach to management are discussed here.     

Autoimmune pancreatitis

Autoimmune pancreatitis is a form of chronic pancreatitis of presumed autoimmune aetiology. The disease is characterised with clinical, serological, histomorphological and imaging features. Autoimmune pancreatitis is recognised as a T-cell-mediated specific disease with lymphoplasmatic infiltration of pancreatic tissue and pancreatic parenchyma fibrosis. Serum immunoglobulin IgG or IgG4 and antibodies (rheumatoid factor, lactoferrin antibodies, carbonic anhydrase II, etc) are usually increased. But the lack of specific biochemical markers is a major drawback in the diagnosis of autoimmune pancreatitis. The Japan Pancreas Society proposed diagnostic criteria for autoimmune pancreatitis as the presence antibodies, pancreas enlargement and pancreatic duct narrowing, lymphoplasmatic infiltration, response to corticosteroid therapy, and association with other autoimmune diseases such as autoimmune hepatitis, sclerosing cholangitis, primary biliary cirrhosis, sialoadenitis, inflammatory bowel disease and Sj?gren syndrome. New criteria (HISORt Criteria) incorporate imaging changes, organ involvement, specific elevation of IgG4 subclass and histopathological markers. Autoimmune pancreatitis could be associated with diabetes mellitus and exocrine pancreatic dysfunction. Clinically, autoimmune pancreatitis is a disease with mild symptoms; severe attacks of abdominal pain are not typical. Typically, pancreatic calcifications and pseudocyst are absent; on the other hand jaundice and/or pancreatic mass are frequent signs, and both make differential diagnosis with pancreatic cancer difficult. From a practical point of view, in an elderly male presenting with obstructive jaundice and pancreatic mass, autoimmune pancreatitis is one of the differential diagnoses to avoid unnecessary surgical therapy.     

Autoimmune pancreatitis]

Over the last years several case reports and articles have been published suggesting that a new form of chronic pancreatitis has been diagnosed and named autoimmune pancreatitis. The present overview scrutinizes the proposed evidence in the light of the current literature and aims to prove whether autoimmune pancreatitis is a special entity of chronic pancreatitis.     

Autoimmune chronic pancreatitis

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis.     

Autoimmune related pancreatitis

Since the first documented case of a particular form of pancreatitis with hypergammaglobulinaemia, similar cases have been reported, leading to the concept of an autoimmune related pancreatitis or so-called "autoimmune pancreatitis". Although it has not yet been widely accepted as a new clinical entity, the present article discusses the recent concept of autoimmune pancreatitis.