Prevalence, diagnosis, and profile of autoimmune pancreatitis presenting with features of acute or chronic pancreatitis

Treatment approaches in autoimmune pancreatitis (Review)

Autoimmune pancreatitis (AIP) is a rare disease. There are two distinct types of AIP: AIP type 1 (AIP-1), a pancreatic manifestation of a multi-organ disease linked to immunoglobulin (Ig)G4, and AIP type 2 (AIP-2), a pancreas-specific disease unrelated to IgG4. The usual course of treatment for AIP is oral corticosteroid medication. Rituximab has also been recommended for recurrent AIP-1 in order to initiate remission and provide ongoing treatment. Immunomodulators such as azathioprine are used to keep certain patients in remission. Evaluation also takes into account a number of pharmacological alternatives, including biologic drugs like anti-tumor necrosis factor therapy, a safe and efficient second-line treatment for AIP-2 relapse or steroid dependence. Corticosteroids and immunosuppressants, which are poorly tolerated due to considerable side effects, are being replaced by other biologic drugs, which may offer a beneficial therapeutic alternative.

Prodromal Signs and Symptoms of Chronic Pancreatitis: A Systematic Review

GOAL

We aimed to extract the percent of signs and symptoms at the time of diagnosis from published studies and to pool these using meta-analytic techniques.

BACKGROUND

Delayed or misdiagnosis of chronic pancreatitis may occur because the signs and symptoms are nonspecific and varied.

STUDY

We performed a systematic review of studies reporting the signs and symptoms of chronic pancreatitis at diagnosis. The percentage of patients with each sign and symptom was extracted and random-effects meta-analyses used to calculate pooled percentages.

RESULTS

In total, 22 observational studies were included. Across 14 studies, 55% of chronic pancreatitis patients were classified as having alcoholic etiology. Abdominal pain was the most common symptom (76%), and weight loss was reported in 22% of patients. Jaundice occurred in 11% of patients and steatorrhoea in 3%. Half of the patients had a history of acute pancreatitis, and 28% had diabetes mellitus at diagnosis. Heterogeneity between the studies was high for all signs and symptoms.

CONCLUSIONS

This research has identified some common features of patients with chronic pancreatitis, but the high heterogeneity makes it difficult to draw solid conclusions. Carefully designed studies to examine the signs and symptoms leading up to a diagnosis of chronic pancreatitis, and common combinations, are required. These would enable the development of a tool to aid in the early identification of chronic pancreatitis in the primary care setting, with potential for improved short-term and long-term outcomes for patients.

The clinical efficacy of azathioprine as maintenance treatment for autoimmune pancreatitis: a systematic review and meta-analysis

The effectiveness of azathioprine (AZA) in preventing relapse and maintaining autoimmune pancreatitis (AIP) remission has been reported; however, most of these studies are case series with no randomized control trials available in the literature. Therefore, this study performed a systematic review and meta-analysis of the existing literature on this subject to determine the clinical efficacy of AZA as maintenance therapy for AIP patients. A systematic search was performed to identify studies on the clinical efficacy of AZA as maintenance therapy in AIP patients. The crude multiple relapse rate was estimated to assess the ability of AZA to control relapses in AIP. Pooled estimates were obtained using a random-effects model with the DerSimonian-Laird method. We identified AIP patients who did not respond to initial steroid treatment, experienced steroid weaning failure, or those who relapsed during remission as refractory cases. After reviewing the studies, ten articles fulfilled the inclusion criteria and were selected for meta-analysis. Of all 4504 patients, 3534 patients were treated with steroids, and 346 patients were treated with AZA for relapsed AIP. In this meta-analysis, 14/73 (19.2%) patients receiving AZA for refractory AIP relapsed. Meanwhile, 14/47 (29.8%) patients without AZA experienced relapse. The integrated odds ratio for relapse risk in patients receiving AZA was estimated to be 0.52 (p = 0.15). This systematic review and meta-analysis demonstrated the efficacy of AZA in preventing relapse of AIP, which supports the use of AZA as a maintenance treatment in patients with AIP who relapse upon withdrawal of steroid therapy.

Imaging in chronic pancreatitis: State of the art review

Chronic pancreatitis (CP) is an important gastrointestinal cause of morbidity worldwide. It can severely impair the quality of life besides life-threatening acute and long-term complications. Pain and pancreatic exocrine insufficiency (leading to malnutrition) impact the quality of life. Acute complications include pseudocysts, pancreatic ascites, and vascular complications. Long-term complications are diabetes mellitus and pancreatic cancer. Early diagnosis of CP is crucial to alter the natural course of the disease. However, majority of the cases are diagnosed in the advanced stage. The role of various imaging techniques in the diagnosis of CP is discussed in this review.

Risk Factors for Pancreatic Stone Formation in Type 1 Autoimmune Pancreatitis: A Long-term Japanese Multicenter Analysis of 624 Patients

OBJECTIVE

Autoimmune pancreatitis (AIP) has the potential to transform into chronic pancreatitis with pancreatic stone involvement. This retrospective investigation sought to clarify the risk factors for stone formation in type 1 AIP.

METHODS

Questionnaires on patients with type 1 AIP were sent to 22 high-volume medical centers across Japan to compare the clinical features of patients with and without pancreatic stone formation.

RESULTS

Of the completed records on 624 type 1 AIP patients, 31 (5%) had experienced pancreatic stones. Median follow-up duration was 1853 days. Bentiromide test values at diagnosis were significantly lower, and hemoglobin A1c values after corticosteroid treatment were significantly higher in patients with pancreatic stones. Imaging results disclosed that pancreatic atrophy and hilar or intrahepatic bile duct stenosis were significantly more frequent in patients with pancreatic stone formation. Pancreatic head swelling tended to be more frequent in this group as well. On the other hand, a shorter follow-up period was associated with the nonformation of pancreatic stones.

CONCLUSIONS

The increased frequency of pancreatic head swelling in type 1 AIP patients exhibiting pancreatic stones indicated a propensity for pancreatic juice stasis with subsequent stone development and pancreatic dysfunction occurring over longer periods of disease duration.

MR Imaging of Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is characterized by autoimmune inflammatory destruction of the pancreatic tissue. Imaging plays an essential role in the diagnosis. AIP type 1 is the pancreatic manifestation of immunoglobulin G4 (IgG4)-related disease and is associated with IgG4-positive plasma cell infiltration and fibrosis of multiple organ systems. Type 2 is a related disease with pancreatic inflammation with or without concurrent inflammatory bowel disease. The authors demonstrate the imaging findings that are associated with the pancreatic and extra-pancreatic manifestations of AIP. They emphasize the common MR imaging and magnetic resonance cholangiopancreatography findings to help make the diagnosis of AIP.

Prevalence and Incidence of Autoimmune Pancreatitis in the Population Living in the Southwest of Germany

BACKGROUND/AIMS

The prevalence and incidence of autoimmune pancreatitis (AiP) in those living in western countries are largely unknown. We aimed to determine the prevalence of AiP among patients with pancreatitis presenting to our tertiary referral center in Mannheim, Germany; and to estimate the incidence of AiP in the Southwest of Germany.

METHODS

We performed a retrospective cross-sectional analysis and determined the prevalence of AiP in patients with acute pancreatitis (AP) or chronic pancreatitis (CP). Patients (n = 704; alcoholic pancreatitis n = 373, nonalcoholic pancreatitis n = 331) were stratified into the Retrospective-Pancreas-Cohort (RPC, period 1998-2008, n = 534) and the Pancreas-Clinic-Cohort (PCC, periods 2008-2010 and 2013-2014, n = 170, with detailed investigation for features of AiP). Diagnosis of AiP was established by International-Consensus-Diagnostic-Criteria and Unifying-Autoimmune-Pancreatitis-Criteria.

RESULTS

In the RPC, the prevalence of AiP was 5.9% (n = 13/221) among individuals with nonalcoholic pancreatitis (n = 1/61 with AP, 1.6%; n = 12/160 with CP, 7.5%). In the PCC, the prevalence of AiP was 9.1% (n = 10/110) among patients with nonalcoholic pancreatitis (n = 2/24 with AP, 8.3%; n = 8/86 with CP, 9.3%), and 1.7% (n = 1/60) among subjects with alcoholic pancreatitis. We estimated the incidence of AiP with 0.29 per 100,000 population each year.

CONCLUSION

The prevalence rate of AiP may account for 9% of patients with nonalcoholic pancreatitis but is almost never observed in patients with alcoholic pancreatitis. The incidence of AiP in Germany appears lower than 1 per 100,000 population.

Increases in IgE, Eosinophils, and Mast Cells Can be Used in Diagnosis and to Predict Relapse of IgG4-Related Disease

BACKGROUND & AIMS

IgG subclass 4-related disease (IgG4-RD) is characterized by increased serum levels of IgG4 and infiltration of biliary, pancreatic, and other tissues by IgG4-positive plasma cells. We assessed the prevalence of allergy and/or atopy, serum, and tissue IgE antibodies, and blood and tissue eosinophils in patients with IgG4-RD. We investigated the association between serum IgE and diagnosis and relapse of this disease.

METHODS

We performed a prospective study of 48 patients with IgG4-RD, 42 patients with an increased serum level of IgG4 with other inflammatory and autoimmune conditions (disease control subjects), and 51 healthy individuals (healthy control subjects) recruited from Oxford, United Kingdom from March 2010 through March 2014, and followed for a median of 41 months (range, 3-73 months). Serum levels of immunoglobulin were measured at diagnosis, during steroid treatment, and at disease relapse for patients with IgG4-RD; levels at diagnosis were compared with baseline levels of control subjects. Allergen-specific IgEs were measured using the IgE ImmunoCAP. Levels and distribution of IgG4 and IgE antibodies in lymphoid, biliary, and pancreatic tissues from patients with IgG4-RD and disease control subjects were measured by immunohistochemistry. We analyzed data using the Spearman rank correlation and receiver operating characteristic curves.

RESULTS

Serum levels of IgG4 increased to 1.4 g/L or more, and IgE increased to 125 kIU/L or more, in 81% and 54% of patients with IgG4-RD, respectively, compared with 6% and 16% of healthy control subjects (P < .0001). Peripheral blood eosinophilia was detected in 38% of patients with IgG4-RD versus 9% of healthy control subjects (P = .004). Of patients with IgG4-RD, 63% had a history of allergy and 40% had a history of atopy with an IgE-specific response; these values were 60% and 53% in patients with increased serum levels of IgE (P < .05). Level of IgE at diagnosis >480 kIU/L distinguished patients with IgG4-RD from disease control subjects with 86% specificity, 36% sensitivity, and a likelihood ratio of 3.2. Level of IgE at diagnosis >380 kIU/L identified patients with disease relapse with 88% specificity, 64% sensitivity, and a likelihood ratio of 5.4. IgE-positive mast cells and eosinophilia were observed in lymphoid, biliary, and pancreatic tissue samples from 50% and 86% of patients with IgG4-RD, respectively.

CONCLUSIONS

In a prospective study, we associated IgG4-RD with allergy, atopy, eosinophilia, increased serum levels of IgE, and IgE-positive mast cells in lymphoid, biliary, and pancreatic tissue. An IgE-mediated allergic response therefore seems to develop in most patients with IgG4-RD; levels of IgE might be used in diagnosis and predicting relapse.

Epidemiology of Recurrent Acute and Chronic Pancreatitis: Similarities and Differences

Emerging data in the past few years suggest that acute, recurrent acute (RAP), and chronic pancreatitis (CP) represent a disease continuum. This review discusses the similarities and differences in the epidemiology of RAP and CP. RAP is a high-risk group, comprised of individuals at varying risk of progression. The premise is that RAP is an intermediary stage in the pathogenesis of CP, and a subset of RAP patients during their natural course transition to CP. Although many clinical factors have been identified, accurately predicting the probability of disease course in individual patients remains difficult. Future studies should focus on providing more precise estimates of the risk of disease transition in a cohort of patients, quantification of clinical events during the natural course of disease, and discovery of biomarkers of the different stages of the disease continuum. Availability of clinically relevant endpoints and linked biomarkers will allow more accurate prediction of the natural course of disease over intermediate- or long-term-based characteristics of an individual patient. These endpoints will also provide objective measures for use in clinical trials of interventions that aim to alter the natural course of disease.

Clinical profiles and outcomes in idiopathic duct-centric chronic pancreatitis (type 2 autoimmune pancreatitis): the Mayo Clinic experience

OBJECTIVE

Idiopathic duct-centric chronic pancreatitis (IDCP), also known as type 2 autoimmune pancreatitis (AIP), is an uncommon subtype of AIP. International Consensus Diagnostic Criteria for IDCP propose that the diagnosis requires pancreatic histology and/or concurrent IBD. We examined our experience with IDCP (type 2 AIP) to assess the appropriateness of these criteria, and identify unique characteristics in patients presenting with acute pancreatitis.

DESIGN

We reviewed the Mayo Clinic AIP database through May 2014 to identify subjects with either definitive (n=31) or probable (n=12) IDCP. We compared demographic and clinical factors based on strength of diagnostic confidence (definitive versus probable), presence of IBD, and acute pancreatitis as the presenting manifestation. Relapse-free survival was determined using the Kaplan-Meier method.

RESULTS

The clinical profiles were similar irrespective of the diagnostic criteria fulfilled. Common clinical presentations included acute pancreatitis (n=25, 58.1%, 12 of whom (27.9%) had recurrent pancreatitis) and pancreatic mass/obstructive jaundice (n=15, 34.9%). The cumulative relapse rate was 10.6% at 3 years (median follow-up 2.9 years). Relapse-free survival was similar for the different diagnostic categories, but was decreased in those initially presenting with acute pancreatitis (p=0.047) or treated with steroids (vs surgery, p=0.049).

CONCLUSIONS

The current diagnostic classification of probable IDCP and the inclusion of IBD as a supportive criterion appear valid, because patients have similar clinical profiles and disease-related outcomes to those with definitive IDCP. Concurrent IBD, especially in young patients, may suggest when IDCP is the underlying cause of recurrent acute pancreatitis, but additional studies are needed for validation.

The management of autoimmunity in patients with cholestatic liver diseases

Cholestatic liver diseases are rare diseases that often lead to cirrhosis and its consequent complications. In addition to liver-related morbidity, patients with cholestatic liver diseases often suffer from autoimmune diseases that affect several organs and tissues. The robust and efficient data collection and collaboration between hepatologists and rheumatologists have led to significant advancements in understanding the relationship between the cholestatic liver diseases and associated autoimmune diseases. In this paper, we discuss the cholestatic liver diseases (primary biliary cirrhosis, primary sclerosing cholangitis and immunoglobulin G4 associated cholangitis) and associated autoimmune diseases.

Autoimmune pancreatitis and cholangitis

Autoimmune pancreatitis (AIP) is part of a systemic fibrosclerotic process characterized by lymphoplasmacytic infiltrate with immunoglobulin G subtype-4 (IgG4) positive cells. It characteristically presents with biliary obstruction due to mass-like swelling of the pancreas. Frequently AIP is accompanied by extra-pancreatic manifestations including retroperitoneal fibrosis, thyroid disease, and salivary gland involvement. Auto-antibodies, hypergammaglobulemia, and prompt resolution of pancreatic and extrapancreatic findings with steroids signify its autoimmune nature. Refractory cases are responsive to immunomodulators and rituximab. Involvement of the biliary tree, termed IgG4 associated cholangiopathy, mimics primary sclerosing cholangitis and is challenging to manage. High IgG4 levels and swelling of the pancreas with a diminutive pancreatic duct are suggestive of autoimmune pancreatitis. Given similarities in presentation but radical differences in management and outcome, differentiation from pancreatic malignancy is of paramount importance. There is controversy regarding the optimal diagnostic criterion and steroid trials to make the diagnosis. Additionally, the retroperitoneal location of the pancreas and requirement for histologic sampling, makes tissue acquisition challenging. Recently, a second type of autoimmune pancreatitis has been recognized with similar clinical presentation and steroid response though different histology, serologic, and extrapancreatic findings.

A new descriptor for computer-aided diagnosis of EUS imaging to distinguish autoimmune pancreatitis from chronic pancreatitis

BACKGROUND AND AIMS

Computer-aided diagnosis of EUS images was quite useful in differentiating pancreatic cancer from normal tissue and chronic pancreatitis. This study investigated the feasibility of using computer-aided diagnostic techniques to extract EUS image parameters to distinguish autoimmune pancreatitis from chronic pancreatitis.

METHODS

A new descriptor, local ternary pattern variance, was introduced to improve the performance of the classification model. Patients with autoimmune pancreatitis (n = 81) or chronic pancreatitis (n = 100) were recruited for this study. Representative EUS images were selected, and 115 parameters from 10 categories were extracted from the region of interest. Distance-between-class and sequential forward selection algorithms were used for their ideal combination of features that allowed a support vector machine predictive model to be built, trained, and validated. The accuracy, sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were used to evaluate the performance of experimental results.

RESULTS

Fourteen parameters from 3 categories were selected as an ideal combination of features. The sample set was randomly divided into a training set and a testing set by using two different algorithms-the leave-one-out algorithm and the half-and-half method. The half-and-half method yielded an average (± standard deviation) accuracy of 89.3 ± 2.7%, sensitivity of 84.1 ± 6.4%, specificity of 92.5 ± 3.3%, PPV of 91.6 ± 3.7%, and NPV of autoimmune pancreatitis of 88.0 ± 4.1%.

CONCLUSIONS

This study shows that, with the local ternary pattern variance textural feature, computer-aided diagnosis of EUS imaging may be valuable to differentiate autoimmune pancreatitis from chronic pancreatitis. Further refinement of such models could generate tools for the clinical diagnosis of autoimmune pancreatitis.

IgG4-Related Disease of the Gastrointestinal Tract: A 21st Century Chameleon

CONTEXT

Immunoglobulin G4 (IgG4)-related disease is a systemic fibroinflammatory disease capable of affecting virtually any organ. Although the pancreas and hepatobiliary system are commonly affected, involvement of the tubular gut is unusual. The pancreatic manifestations of this disease (autoimmune pancreatitis) often mimic pancreatic carcinoma, whereas the hepatobiliary manifestations are mistaken for cholangiocarcinoma or primary sclerosing cholangitis. The characteristic histologic features include a dense lymphoplasmacytic infiltrate, storiform-type fibrosis, and obliterative phlebitis. An increase in IgG4(+) plasma cells and an IgG4 to IgG ratio of more than 40% are considered obligatory components of the diagnostic algorithm.

OBJECTIVE

To review the challenges associated with the diagnosis of IgG4-related disease of the gastrointestinal tract.

DATA SOURCES

A review of pertinent literature, along with the author's personal experience, based on institutional and consultation materials.

CONCLUSION

The complete spectrum of histologic changes is seldom captured in a biopsy specimen, and thus, the histopathology findings are best interpreted within the overall clinical context. Increased IgG4(+) plasma cells are identified in a variety of benign and malignant diseases of the gastrointestinal tract.

Recent developments in steroid-responsive pancreatitides (autoimmune pancreatitis)

PURPOSE OF REVIEW

There are two distinct steroid responsive chronic fibro-inflammatory diseases of the pancreas, called type 1 and type 2 autoimmune pancreatitis (AIP). We review recent progress in this field.

RECENT FINDINGS

It has recently been suggested that the term AIP be used to describe type 1 AIP and the term idiopathic duct-centric chronic pancreatitis (IDCP) be used for type 2 AIP. Clinical features and long-term outcomes of AIP and IDCP are well characterized and prognosis of both diseases is excellent. Diagnostic strategies tailored to regional practice patterns have emerged with the application of International Consensus Diagnostic Criteria for AIP. Although corticosteroids remain the mainstay of treatment, management of relapses and strategies for preventing multiple relapses are better understood, including the role of maintenance therapy and B-cell depletion therapy with rituximab. Association studies with malignancies have yielded conflicting results regarding risk of cancer in AIP.

SUMMARY

The treatment, follow-up guidelines and associations continue to evolve with our increasing experience with both AIP and IDCP. In AIP, rituximab can be used for both induction and maintenance of remission. IDCP responds to steroids without need for maintenance therapy. Both AIP and IDCP have excellent prognosis.

Extracorporeal shock wave lithotripsy treatment of pancreatic stones complicated with advanced stage autoimmune pancreatitis

BACKGROUND

Although most patients with autoimmune pancreatitis (AIP) respond favorably to prednisolone therapy, some individuals who later suffer from pancreatic calculi may require additional extracorporeal shock wave lithotripsy (ESWL) treatment. This study compares the efficacy of ESWL for calculi in AIP with that in ordinary chronic pancreatitis (CP) and proposes a new treatment approach for pancreatic duct stones occurring in AIP.

METHODS

We examined the clinical records of 8 patients with chronic stage AIP and 92 patients with ordinary CP who received ESWL for pancreatic calculi.

RESULTS

The AIP group was significantly older than the CP group (69.0 vs. 56.5 years, P = 0.018). With regard to the indications for ESWL, chronic pain was significantly less frequent in the chronic stage AIP group (0% vs. 45.7%, P = 0.001), whereas preservation of pancreatic function was significantly more frequent (75% vs. 19.6%, P = 0.001). Compared with the CP group, the AIP group tended to exhibit pancreatic duct stenosis proximal to pancreatic calculi and had a lower rate of complete extraction of stones from the main pancreatic duct. Histopathological analysis of a patient with chronic stage AIP revealed widely distributed nodular pancreatitis, which was characteristic of ordinary CP, along with isolated areas of lymphoplasmacytic sclerosing pancreatitis.

CONCLUSIONS

Different approaches are needed for the treatment of pancreatic calculi in chronic stage AIP and ordinary CP. Specifically, it appears that intensive ESWL therapy can be avoided or delayed in AIP if the patient displays: (1) advanced age, (2) little or no chronic pain or pancreatitis, and (3) pancreatic duct stenosis proximal to pancreatic stones. In such cases, the benefit of ESWL treatment may be outweighed by the risks involved in this procedure.

Magnetic resonance imaging of pancreatitis: An update

Magnetic resonance (MR) imaging plays an important role in the diagnosis and staging of acute and chronic pancreatitis and may represent the best imaging technique in the setting of pancreatitis due to its unmatched soft tissue contrast resolution as well as non-ionizing nature and higher safety profile of intravascular contrast media, making it particularly valuable in radiosensitive populations such as pregnant patients, and patients with recurrent pancreatitis requiring multiple follow-up examinations. Additional advantages include the ability to detect early forms of chronic pancreatitis and to better differentiate adenocarcinoma from focal chronic pancreatitis. This review addresses new trends in clinical pancreatic MR imaging emphasizing its role in imaging all types of acute and chronic pancreatitis, pancreatitis complications and other important differential diagnoses that mimic pancreatitis.

Pancreatitis-imaging approach

Pancreatitis is defined as the inflammation of the pancreas and considered the most common pancreatic disease in children and adults. Imaging plays a significant role in the diagnosis, severity assessment, recognition of complications and guiding therapeutic interventions. In the setting of pancreatitis, wider availability and good image quality make multi-detector contrast-enhanced computed tomography (MD-CECT) the most used imaging technique. However, magnetic resonance imaging (MRI) offers diagnostic capabilities similar to those of CT, with additional intrinsic advantages including lack of ionizing radiation and exquisite soft tissue characterization. This article reviews the proposed definitions of revised Atlanta classification for acute pancreatitis, illustrates a wide range of morphologic pancreatic parenchymal and associated peripancreatic changes for different types of acute pancreatitis. It also describes the spectrum of early and late chronic pancreatitis imaging findings and illustrates some of the less common types of chronic pancreatitis, with special emphasis on the role of CT and MRI.

Recent advances in the diagnosis and management of autoimmune pancreatitis

OBJECTIVE

Autoimmune pancreatitis (AIP) is a rare chronic relapsing steroid-responsive fibroinflammatory disorder of the pancreas that is likely caused by immune dysregulation. It is now thought that AIP consists of two distinct clinicopathologic syndromes currently designated as types 1 and 2.

CONCLUSION

A current update on etiopathogenesis, pathology, and clinical and imaging findings of AIP is provided with an emphasis on diagnosis and management.

Autoimmune pancreatitis can develop into chronic pancreatitis

Autoimmune pancreatitis (AIP) has been recognized as a distinct type of pancreatitis that is possibly caused by autoimmune mechanisms. AIP is characterized by high serum IgG4 and IgG4-positive plasma cell infiltration in affected pancreatic tissue. Acute phase AIP responds favorably to corticosteroid therapy and results in the amelioration of clinical findings. However, the long-term prognosis and outcome of AIP remain unclear. We have proposed a working hypothesis that AIP can develop into ordinary chronic pancreatitis resembling alcoholic pancreatitis over a long-term course based on several clinical findings, most notably frequent pancreatic stone formation. In this review article, we describe a series of study results to confirm our hypothesis and clarify that: 1) pancreatic calcification in AIP is closely associated with disease recurrence; 2) advanced stage AIP might have earlier been included in ordinary chronic pancreatitis; 3) approximately 40% of AIP patients experience pancreatic stone formation over a long-term course, for which a primary risk factor is narrowing of both Wirsung’s and Santorini’s ducts; and 4) nearly 20% of AIP patients progress to confirmed chronic pancreatitis according to the revised Japanese Clinical Diagnostic Criteria, with independent risk factors being pancreatic head swelling and non-narrowing of the pancreatic body duct.

Immunosuppressive drugs for the treatment of autoimmune pancreatitis

Autoimmune pancreatitis is one of the few diseases of the pancreas characterized by the possibility of curing the illness using immunosuppressant drugs. In this paper, the therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality were reviewed. Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open, such as a shared definition of the disease’s remission as well as autoimmune pancreatitis relapse, the dosage of steroids in the symptomatic phase of the disease and the duration of steroid therapy. Finally, it should be determined if other immunosuppressive nonsteroidal drugs could become first-line therapy in patients with autoimmune pancreatitis without jaundice and without atrophic pancreas.

The epidemiology of pancreatitis and pancreatic cancer

Acute pancreatitis is one of the most frequent gastrointestinal causes of hospital admission in the United States. Chronic pancreatitis, although lower in incidence, significantly reduces patients' quality of life. Pancreatic cancer is associated with a high mortality rate and is one of the top 5 causes of death from cancer. The burden of pancreatic disorders is expected to increase over time. The risk and etiology of pancreatitis differ with age and sex, and all pancreatic disorders affect the black population more than any other race. Gallstones are the most common cause of acute pancreatitis, and early cholecystectomy eliminates the risk of future attacks. Alcohol continues to be the single most important risk factor for chronic pancreatitis. Smoking is an independent risk factor for acute and chronic pancreatitis, and its effects could synergize with those of alcohol. Significant risk factors for pancreatic cancer include smoking and non-O blood groups. Alcohol abstinence and smoking cessation can alter the progression of pancreatitis and reduce recurrence; smoking cessation is the most effective strategy to reduce the risk of pancreatic cancer.

Type 1 autoimmune pancreatitis can transform into chronic pancreatitis: a long-term follow-up study of 73 Japanese patients

Some patients with autoimmune pancreatitis (AIP) form pancreatic stones suggestive of transformation into chronic pancreatitis (CP). The present study examined the underlying risk factors and mechanism of AIP progression to confirmed CP. We compared the clinical and laboratory parameters of subjects who progressed to confirmed CP with those of the subjucts who did not in a cohort of 73 type 1 AIP patients. A total of 16 (22%) AIP patients progressed to CP. Univariate analysis revealed that relapse was significantly more frequent in the progression group, and multivariate analysis indicated that pancreatic head swelling (OR 12.7, P = 0.023) and nonnarrowing of the main pancreatic duct in the pancreatic body (OR 12.6, P = 0.001) were significant independent risk factors for progression to CP. Kaplan-Meier testing showed that the progression rate to CP was approximately 10% at 3 years and 30% at 10 years in total AIP patients and 30% at 3 years and 60% at 10 years in subjects with both risk factors. AIP with pancreatic head swelling and a history of relapse may cause pancreatic juice stagnation and nonnarrowing of the main pancreatic duct in the pancreatic body, which can progress to advanced stage chronic pancreatitis.

Autoimmune pancreatitis: current concepts

Autoimmune pancreatitis (AIP) is a distinct type of chronic pancreatitis with unique clinical, pathological, serological, and imaging features. AIP usually presents with obstructive jaundice. Imaging studies often reveal enlargement of the pancreas with a pancreatic mass and strictures of the main pancreatic duct. Two subtypes of AIP have recently been identified. Type I AIP is more prevalent in elderly Asian males and is characterized by lymphoplasmacytic sclerosing pancreatitis, obliterative phlebitis, and infiltration of large numbers of IgG4-positive plasma cells. Type II AIP is more prevalent in Caucasians and is characterized by granulocyte epithelial lesions. Most patients with type I AIP have a significantly elevated serum IgG4 concentration, which is an important feature for diagnosis and for differentiating between AIP and other conditions such as pancreatic cancer. Extrapancreatic complications are common, such as sclerosing cholangitis, sclerosing sialadenitis, retroperitoneal fibrosis in type I AIP, and ulcerative colitis in type II AIP. A rapid response to glucocorticoids treatment is suggestive of AIP, but the relapse rate is high, warranting the use of immunosuppressant treatment. B-cell depletion with rituximab may be a promising therapy. The prognosis of AIP is generally benign if treated promptly, and spontaneous remission occurs in a proportion of patients.

Autoimmune cholangitis and cholangiocarcinoma

Autoimmune cholangitis, immunoglobulin G4-associated cholangitis (IAC), is a part of multiorgan IgG4-related systemic disease, which was recognized as a new clinicopathological entity in recent years. IAC is defined as a biliary stricture that responds to steroid therapy, frequently is associated with other fibrosing conditions, especially autoimmune pancreatitis and is characterized by elevation of IgG4 in serum and infiltration of IgG4 positive plasma cells in bile ducts. Since IAC shares a number of clinical, biochemical, and imaging features with cholangiocarcinoma (CCA), it is often misdiagnosed as CCA, and unnecessary surgery was performed. In this compact review, we clarify the disease of IAC, summarize criteria for diagnosis of IAC, discuss the role of CA 19-9, and provide key information to differentiate diagnosis of IAC from CCA. IAC should be highly suspected in unexplained biliary stricture associated with increased IgG4 (in serum especially in bile) and other organ involvement (kidney, retroperitoneum etc. especially pancreas in which there are abundant IgG4-positive plasmocytes infiltration). Correct diagnosis of IAC will avoid unnecessary surgery because IAC responds well to steroid therapy. In a word, increased IgG4 levels, other organ involvement and response to steroids are keys to distinguishing IAC from CCA.

Diagnosis of autoimmune pancreatitis vs neoplasms in children with pancreatic mass and biliary obstruction

Autoimmune pancreatitis (AIP) is a rare autoimmune disorder that resembles pancreatic neoplasia and occurs primarily in adults. Management strategies and diagnostic criteria are being revised for adult patients; there are no clear diagnostic criteria for pediatric patients. We describe 3 cases of AIP in children, on the basis of clinical and pathology records. We also performed a literature review to determine the incidence of biliary obstruction in pediatric patients with pancreatic tumors. We found that children with AIP present with a variety of symptoms, and that diagnostic and therapeutic strategies also vary. Furthermore, on the basis of the many studies published on pediatric patients with pancreatic tumors, only a small percentage of the patients have biliary obstructions. Cytologic analysis of samples collected by fine-needle aspiration cytology does not accurately identify AIP in children. However, frozen section needle core biopsy samples can be used to distinguish children with AIP from those with neoplasia. Children with pancreatic mass and biliary obstruction are more likely to have AIP than neoplasms.

Autoimmune pancreatitis: an update on classification, diagnosis, natural history and management

Autoimmune Pancreatitis (AIP) is a recently recognized chronic fibro-inflammatory disease of the pancreas. Although rare, its recognition continues to increase worldwide. Patients often present with painless obstructive jaundice mimicking pancreatic cancer. Two subtypes of AIP are known-type 1 is a multi-organ disease associated with IgG4; type 2 appears to be a pancreas-specific disorder. Dramatic response to steroid treatment is characteristic of both forms. A non-invasive diagnosis of type 1 AIP may be possible using diagnostic criteria (in ~70% cases) while diagnosis of type 2 requires histology. These subtypes differ in natural history- type 1 often relapses while initial reports suggest that type 2 does not. Long term complications include endocrine and exocrine insufficiency and in case of type 1, disease relapses and complications from extra-pancreatic involvement. Neither form affects long term survival. The treatment and follow-up guidelines continue to evolve with our increasing experience in AIP.

Extraintestinal manifestations of autoimmune pancreatitis

The term autoimmune pancreatitis (AIP) was first used in Japan in 1995 to describe a newly recognized form of chronic pancreatitis, after the description of Yoshida and colleagues. But Sarles in 1961, first described a form of idiopathic chronic inflammatory sclerosis of the pancreas, suspected to be due to an autoimmune process. AIP has become a widely accepted term because clinical, serologic, histologic, and immunohistochemical findings suggest an autoimmune mechanism. Most affected patients have hypergammaglobulinemia and increased serum levels of IgG, particularly IgG4. Recently published International Consensus Diagnostic Criteria for Autoimmune Pancreatitis include Guidelines of the International Association of Pancreatology, classifying AIP into types 1 and 2, using five cardinal features of AIP, namely imaging of pancreatic parenchyma and duct, serology, other organ involvement, pancreatic histology, and an optional criterion of response to steroid therapy. Extrapancreatic presentations can include sclerosing cholangitis, retroperitoneal fibrosis, sclerosing sialadenitis (Küttner tumor), lymphadenopathy, nephritis, and interstitial pneumonia. Increased IgG4+ plasma cell infiltrate has been reported in sclerosing lesions from other organ sites, including inflammatory pseudotumors of the liver, breast, mediastinum, orbit, and aorta, and it has been observed with hypophysitis and IgG4-associated prostatitis. Abundant IgG4+ plasma cells were also confirmed in Riedel thyroiditis, sclerosing mesenteritis, and inflammatory pseudotumor of the orbit and stomach. Extrapancreatic lesions could be synchronously or metachronously diagnosed with AIP, sharing the same pathological conditions, showing also a favorable result to corticosteroid therapy and distinct differentiation between IgG4-related diseases from the inherent lesions of the corresponding organs.

Risk factors for pancreatic stone formation in autoimmune pancreatitis over a long-term course

BACKGROUND

Autoimmune pancreatitis (AIP) has the potential to progress to a chronic state that forms pancreatic stones. The aim of this study was to clarify the risk factors underlying pancreatic stone formation in AIP.

METHODS

Sixty-nine patients with AIP who had been followed for at least 3 years were enrolled for evaluation of clinical and laboratory factors as well as computed tomography and endoscopic retrograde cholangiopancreatography findings.

RESULTS

During the course of this study, increased or de novo stone formation was seen in 28 patients, who were defined as the stone-forming group. No stones were observed in 32 patients, who were defined as the non-stone-forming group. Nine patients who had stones at diagnosis but showed no change during the course of this study were excluded from our cohort. Univariate analysis revealed no significant differences in clinical or laboratory factors associated with AIP-specific inflammation between the two groups. However, pancreatic head swelling (P = 0.006) and narrowing of both Wirsung's and Santorini's ducts in the pancreatic head region (P = 0.010) were significantly more frequent in the stone-forming group. Furthermore, multivariate analysis identified Wirsung and Santorini duct narrowing at diagnosis as a significant independent risk factor for pancreatic stone formation (OR 4.4, P = 0.019).

CONCLUSIONS

A primary risk factor for pancreatic stone formation in AIP was narrowing of both Wirsung's and Santorini's ducts, which most presumably led to pancreatic juice stasis and stone development.

Diagnosis and management of autoimmune pancreatitis

• AIP is a heterogeneous disease with two distinct subtypes, now called type 1 and type 2. The proportions of these subtypes vary in their distribution worldwide. • Pancreatic cancer is the leading differential diagnosis for AIP, although AIP can mimic any other major pancreatobiliary disease. • Cross-sectional abdominal imaging CT/MRI should form the cornerstone to the diagnosis of AIP. • Serum IgG4 provides collateral evidence for the diagnosis of AIP and should not be the sole basis for the diagnosis. False-positive elevation in serum IgG4 can be seen in up to 10% of patients with pancreatic cancer. • A steroid trial should be performed only in select situations after ruling out pancreatic cancer and by gastroenterologists experienced in treating AIP. • Disease recurrence can be seen in up to 40% of patients after initial steroid therapy.

Immunoglobulin G4 immunostaining of gastric, duodenal, or colonic biopsies is not helpful for the diagnosis of autoimmune pancreatitis

BACKGROUND & AIMS

The aim of this study was to evaluate the specificity of the infiltration of digestive tract mucosa by immunoglobulin (Ig) G4-positive plasma cells in patients with autoimmune pancreatitis (AIP), as compared with normal or inflammatory mucosa.

METHODS

Plasma cell infiltration, CD138 and IgG4 immunostaining of digestive biopsies were compared in 4 groups of patients: AIP type 1 (n = 19); AIP type 2 (n = 4) with inflammatory bowel disease (IBD); IBD without pancreatic disorders (n = 20); and controls (n = 26).

RESULTS

With AIP type 1 versus controls, more plasma cells were present in the gastric mucosa of AIP (P = .02) without difference concerning IgG4+ plasma cells at any biopsy site. With AIP type 1 versus IBD, colonic mucosa was more often abnormal (P = .004), and more CD138 (P = .02) and IgG4 plasma cells (P = .0002) were counted in the colon biopsies of IBD. With AIP type 2 versus IBD, no difference for plasma cell and IgG4 infiltration was found.

CONCLUSIONS

IgG4-positive plasma cells are not more numerous in the digestive mucosa of AIP patients than in controls, but they are more abundant in the colon of IBD patients than in AIP patients.

Therapeutic management and clinical outcome of autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis, in comparison to other benign chronic pancreatic diseases, is characterized by the possibility of curing the illness with immunosuppressant drugs. The open question is whether to differentiate autoimmune pancreatitis as a primary or secondary disease based on the presence or absence of other autoimmune diseases or whether to consider autoimmune pancreatitis a clinical and pathological systemic entity, called IgG4-related sclerosing disease, since this aspect is also very important from a therapeutic point of view.

METHODS

In this paper, we reviewed the conventional therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality. We also reviewed some aspects which are important for the correct management of autoimmune pancreatitis, such as the surgical approach, the outcome of surgically treated autoimmune pancreatitis patients, whether medical treatment is always necessary, and, finally, when medical treatment should be initiated.

CONCLUSIONS

Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open such as the dosage of steroids in the acute phase and the duration of steroid therapy; finally, it should be assessed if other immunosuppressive non-steroidal drugs may become the first-line therapy in patients with AIP without jaundice and without atrophic pancreas.

A practical approach to the diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis is a disease characterized by specific pathological features, different from those of other forms of pancreatitis, that responds dramatically to steroid therapy. The pancreatic parenchyma may be diffusely or focally involved with the possibility of a low-density mass being present at imaging, mimicking pancreatic cancer. Clinically, the most relevant problems lie in the diagnosis of autoimmune pancreatitis and in distinguishing autoimmune pancreatitis from pancreatic cancer. Since in the presence of a pancreatic mass the probability of tumour is much higher than that of pancreatitis, the physician should be aware that in focal autoimmune pancreatitis the first step before using steroids is to exclude pancreatic adenocarcinoma. In this review, we briefly analyse the strategies to be followed for a correct diagnosis of autoimmune pancreatitis.

Review article: autoimmune pancreatitis - management of an emerging disease

BACKGROUND

Autoimmune pancreatitis is a steroid-responsive inflammatory pancreatic disease considered to be part of an immunoglobulin G4 (IgG4)-associated systemic disease.

AIM

To review the management of autoimmune pancreatitis.

METHODS

We conducted a PubMed search using the following key words: autoimmune pancreatitis, IgG4-associated systemic disease, IgG4-associated cholangitis, diagnosis, natural history, treatment.

RESULTS

Although there are reports of spontaneous resolution of autoimmune pancreatitis, steroids have been shown to be effective in inducing remission, reducing the frequency of relapse and that of long-term unfavourable events compared to historical controls. There are no randomised data on autoimmune pancreatitis treatment. Oral steroids are used for induction of remission. Reported response results are excellent with variable proportions of patients achieving remission in different studies. After a period of 2-4 weeks, steroids are tapered and usually withdrawn within several months, although long-term maintenance therapy for all autoimmune pancreatitis patients has also been proposed. Disease relapse occurs in more than 40% of patients and can be effectively treated with additional immunosuppression, including azathioprine.

CONCLUSIONS

Steroids are effective in inducing remission and in treating relapse in patients with autoimmune pancreatitis. Randomised trials on autoimmune pancreatitis therapy are lacking. To date, questions concerning the timing, choice and duration of long-term immunosuppression remain unanswered.

Serum IgG4-negative autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis (AIP) is considered to be a pancreatic lesion of IgG4-related systemic disease, but about 20% of AIP patients do not have elevated serum IgG4 levels. This study aimed to clarify the pathophysiology of AIP patients without elevated serum IgG4 levels.

METHODS

Fifty-eight AIP patients were divided into 2 groups: those with elevated serum IgG4 levels (>135 mg/dl; SIgG4-positive AIP) and those without (SIgG4-negative AIP). The 2 groups' clinical, serological, radiological, and histological findings, as well as salivary and lacrimal gland function, were compared.

RESULTS

Serum IgG4 levels were elevated in 45 AIP patients and normal in 13 patients. In SIgG4-negative AIP patients, the female ratio tended to be high; obstructive jaundice was less likely; abdominal pain and acute pancreatitis were more likely; segmental swelling of the pancreatic body and/or tail was more common; sclerosing extrapancreatic lesions, salivary and lacrimal gland dysfunction, and abundant infiltration of IgG4-positive plasma cells in the gastric mucosa were less likely; and conservative follow-up was sometimes implemented. Histological examination of the pancreas of SIgG4-negative AIP showed lymphoplasmacytic sclerosing pancreatitis (LPSP) rather confined to the pancreas (n = 4), inadequate material (n = 2), and pancreatic fibrosis showing infiltration of lymphocytes without infiltration of IgG4-positive cells or neutrophils (n = 2).

CONCLUSIONS

Clinicopathological features of SIgG4-negative AIP differed from those of SIgG4-positive AIP. Some SIgG4-negative AIP cases are LPSP rather confined to the pancreas. SIgG4-negative AIP may include idiopathic duct-centric pancreatitis (IDCP) or sclerosing pancreatitis other than LPSP or IDCP, but further studies are needed to clarify this issue.

IgG₄-related sclerosing disease: a novel mimic of inflammatory bowel disease

High levels of IgG₄-positive plasma cells are commonly seen in autoimmune pancreatitis. It has recently become evident that autoimmune pancreatitis is one component of a larger multi-system disease. IgG₄-positive plasma cells have been identified in many extrapancreatic tissues, including the colon, biliary tract, liver, and lungs, and thus the term "IgG₄-related sclerosing disease" has been proposed. Awareness of IgG₄-related sclerosing disease is important, as it has been shown to mimic other conditions like malignancy. This review discusses IgG₄-related colitis and its potential for mimicking inflammatory bowel disease.

A long-term follow-up study on endoscopic management of children and adolescents with chronic pancreatitis

OBJECTIVES

Data on therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for chronic pancreatitis (CP) in children and adolescents, especially with long-term follow-up of consequences, are rarely reported. The aim of this study was to determine the long-term follow-up results of therapeutic ERCP for CP in children and adolescents.

METHODS

All patients with CP who received therapeutic ERCP at Changhai Hospital from January 1997 to May 2009, with the age at first onset of pain being less than 18.0 years, were included. Attempts were made to contact all adolescents and follow-up data were recorded. Clinical data were assessed before and after every ERCP.

RESULTS

Follow-up information was available in 42 (91.3%) of the 46 patients who received therapeutic ERCP. There were 20 boys and 22 girls, with the age at first onset being 11.8+/-4.5 years. A total of 110 therapeutic ERCP sessions were performed in the 42 patients. The post-ERCP complication rate was 17.3%, including mild and moderate pancreatitis (n=17) and mild cholangitis (n=2). The mean follow-up period of time was 61.4 (range: 24-132) months. Five patients underwent subsequent surgery because of refractory abdominal pain after endotherapy. Of the remaining 37 patients who received therapeutic ERCP alone, abdominal pain improved in 30 (81.1%) patients, and was completely relieved in 24 (64.9%) patients during the period of follow-up.

CONCLUSIONS

Therapeutic ERCP may offer long-term improvement in pain in children and adolescents with CP.