Development of Pancreatic Cancer during the Follow-up of Autoimmune Pancreatitis: A Report of Two Cases

Autoimmune pancreatitis (AIP) is considered to have a good steroid response and is recognized as a disease with a favorable prognosis. However, it has been reported that patients with AIP have malignant diseases. We herein report two cases of pancreatic cancer during the follow-up of AIP, in which both patients died of pancreatic cancer. Patients with AIP may be at a high risk of malignant diseases, including pancreatic cancer, and medium- to long-term follow-up may be necessary.

Gastric Varices Rupture due to Splenic Vein Obstruction Associated with Autoimmune Pancreatitis

A 60-year-old man with a high IgG4 level was found to have pancreatic tail enlargement on computed tomography (CT), and autoimmune pancreatitis (AIP) was confirmed by a histological diagnosis. He was treated with prednisolone for one year and seven months, at which point his treatment finished. Four months later, however, he had hematemesis from gastric varices. CT showed recurrence of pancreatic tail enlargement with obstruction of the splenic artery and vein and formation of collateral blood vessels to the gastric fornix. Endoscopic injection sclerotherapy was performed, and he underwent splenectomy. This case highlights the importance of paying attention to peripancreatic vascular abnormalities during follow-up of AIP patients.

Clinical features and long-term outcomes of patients with type 2 autoimmune pancreatitis

OBJECTIVES

Type 2 is a rare form of autoimmune pancreatitis (AIP). Despite being considered a benign disease, only few studies with limited sample size and short follow-up have been published on type 2 AIP. The aim of this observational study was to evaluate long-term outcomes, such as the risk of relapse, pancreatic insufficiency and cancer in a large type 2 AIP cohort with long follow-up.

METHODS

Patients with definitive or probable diagnosis of type 2 AIP by International Consensus Diagnostic Criteria (ICDC) present in our prospectively maintained database since 1995 at 31.12.2021 were identified. All patients were clinically evaluated during the year 2022. Clinical, radiological, serological, and pathological data were evaluated.

RESULTS

Eighty-eight out of 420 patients present in the database (21%) were diagnosed with type 2 AIP (mean age 33.5 ± 13.5 years). According to the ICDC, 21 patients (23.8%) had a definitive and 67 (76.2%) a probable diagnosis of type 2 AIP. The mean follow-up was 9.2 ± 7.1 years (range 1-27 years). No differences were observed when comparing patients with definitive and probable type 2 AIP diagnosis. Concomitant IBD was reported in 77 patients (87.5%). The probability of disease relapse was lower in patients treated with steroids versus surgery (at 5 years 13% vs. 33%; p = 0.038) but this difference was not statistically significant at multivariable analysis. The risk of endocrine or severe exocrine insufficiency was low (5% and 25%). Four extra-pancreatic malignancies (5%) were diagnosed, none pancreatic. One patient died in a car accident.

CONCLUSIONS

Type 2 AIP has benign long-term clinical outcomes. Mortality and cancer rates are low and no specific follow-up is needed after radiological remission.

Immune Checkpoint Inhibitor-induced Pancreatitis with Pancreatic Enlargement Mimicking Autoimmune Pancreatitis: A Case Report and Review of the Literature

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

IgG4-related pancreatobiliary diseases could be associated with onset of pancreatobiliary cancer: A multicenter cohort study

BACKGROUND

The risk and prognosis of pancreatobiliary cancer and in patients with autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) remain unclear. Therefore, we retrospectively investigated the risk of pancreatobiliary cancer and prognosis in patients with AIP and IgG4-SC.

METHODS

Patients with AIP and IgG4-SC at seven centers between 1998 and 2022 were investigated. The following data were evaluated: (1) the number of cancers diagnosed and standardized incidence ratio (SIR) for pancreatobiliary and other cancers during the observational period and (2) prognosis after diagnosis of AIP and IgG4-SC using standardized mortality ratio (SMR).

RESULTS

This study included 201 patients with AIP and IgG4-SC. The mean follow-up period was 5.7 years. Seven cases of pancreatic cancer were diagnosed, and the SIR was 8.11 (95% confidence interval [CI]: 7.29-9.13). Three cases of bile duct cancer were diagnosed, and the SIR was 6.89 (95% CI: 6.20-7.75). The SMR after the diagnosis of AIP and IgG4-SC in cases that developed pancreatobiliary cancer were 4.03 (95% CI: 2.83-6.99).

CONCLUSIONS

Patients with autoimmune pancreatitis and IgG4-SC were associated with a high risk of pancreatic and bile duct cancer. Patients with AIP and IgG4-SC have a worse prognosis when they develop pancreatobiliary cancer.

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.

Autoimmune Polyglandular Syndrome Type 3 Complicated with IgG4-related Disease

A 52-year-old Japanese woman developed type 1 diabetes mellitus (type 1 DM) at 41 years old. She became complicated with Hashimoto's disease and showed swelling of both submandibular glands, which was diagnosed as IgG4-related disease (IgG4-RD). This is a rare case of a Japanese patient with autoimmune polyglandular syndrome type 3A (APS-3A) coexisting with autoimmune thyroid disease (AITD) and type 1 DM complicated by IgG4-RD. Bilateral submandibular gland resection was successfully performed without steroid therapy. We discuss the possibility that the immunological pathogenic mechanisms of APS-3A and IgG4-RD are related.

Type 2 autoimmune pancreatitis associated with ulcerative colitis

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disease mainly affecting the rectum and colon and causing diarrhoea and mucopurulent stools. UC can present with extraintestinal manifestations in various organs and systems and can be associated with various comorbidities. Autoimmune pancreatitis (AIP) is a specific type of pancreatitis associated with autoimmune abnormalities and is divided into two clinical types: type 1 (lymphoplasmacytic sclerosing pancreatitis) and type 2 (idiopathic ductocentric pancreatitis). The current study shows an association between type 2 AIP and UC, which may be related to genetic susceptibility, inflammatory factors, and immune response. The most common manifestation of AIP in patients with type 2 AIP-UC is abdominal pain with elevated pancreatic enzymes, whereas the presentation of UC in type 2 AIP-UC is more severe, with an increased risk of UC-related surgery. This review focuses on diagnosis, prevalence, pathogenesis, impact, and treatment to better understand type 2 AIP-UC, explore the molecular mechanisms of this condition, and encourage further research into the management of type 2 AIP-UC.

Association of autoimmune pancreatitis with Raghib syndrome

Key Clinical Message

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis scarcely found in children. Raghib syndrome is a rare congenital heart defect known as persistent left superior vena cava (LSVC) draining into the left atrium. Total signs of Raghib syndrome in AIP case accompanied by an IgG4-related disease were described.

Abstract

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis scarcely found in children. Raghib syndrome is a rare congenital heart defect known as persistent left superior vena cava (LSVC) draining into the left atrium. Here, we describe Raghib syndrome in AIP case accompanied by an IgG4-related disease (AIP/IgG4RD). A 13-year-old boy presented with a 3-month history of fever and abdominal pain. The laboratory findings showed SGOT and SGPT, ALP was increased, while amylase and γ-GT were normal. Immunoglobulins were normal, except for IgG. Endosonography, spiral CT of the abdomen, and cholangiopancreatography showed an enlargement of the pancreas. Contrast echocardiography discovered opacification of the coronary sinus and left atrium. Transesophageal echocardiography for LSVC revealed a dilatation in the coronary sinus, indicating persistent LSVC. Following the injection of agitated saline into the left antecubital vein, bubbles entered both left and right atria in LSVC. It is reasonable to exclude some of these rare disorders as Raghib syndrome, in cases that will be started on medications like corticosteroids, which increases the susceptibility to thromboembolic events.

Long-term Outcomes after Steroid Pulse Therapy in Patients with Type 1 Autoimmune Pancreatitis

Objective Steroid pulse therapy is a regimen involving the intravenous administration of supra-pharmacological doses of corticosteroids in the short term. It is used to treat various inflammatory and autoimmune conditions. However, the strengths and limitations of steroid pulse therapy for induction of remission in type 1 autoimmune pancreatitis (AIP) are unknown. Methods Depending on the steroid therapy regimen administered, the 104 patients with type 1 AIP included in this retrospective study were divided into three groups: conventional oral prednisolone (PSL) regimen (PSL group), intravenous methylprednisolone (IVMP) pulse followed by oral PSL regimen (Pulse+PSL group), and IVMP pulse-alone regimen (Pulse-alone group). We then examined the relapse rate and adverse events among the three groups. Results The Kaplan-Meier estimates of the relapse rate at 36 months after steroid therapy were 13.6% in the PSL group, 13.3% in the Pulse+PSL group, and 46.2% in the Pulse-alone group. The log-rank test revealed that the relapse-free survival in the Pulse-alone group was significantly shorter than that in the PSL (p=0.024) and Pulse+PSL groups (p=0.014). The exacerbation of glucose tolerance after steroid therapy was less frequently observed in the Pulse-alone group (0%) than in the PSL group (17%, p=0.050) and Pulse+PSL groups (26%, p=0.011). Conclusion Although treatment with IVMP pulse alone resulted in unsatisfactory relapse prevention outcomes compared with conventional steroid therapy, the IVMP pulse-alone regimen might be an alternative treatment strategy for type 1 AIP from the perspective of avoiding adverse events from steroids.

Type 1 Autoimmune Pancreatitis Masquerading as Pancreatic Head Carcinoma

Obstructive jaundice is a joint clinical presentation with many etiologies, including pancreatic cancer and autoimmune pancreatitis (AIP). Differentiating between these two conditions is pivotal due to the divergent management approaches and prognoses. In this case report, we present a case of a 49-year-old female patient who presented with weight loss, intermittent chronic abdominal pain, and jaundice. She was initially suspected of having pancreatic cancer because of clinical presentation and imaging findings. However, she was ultimately diagnosed with Type 1 AIP due to histopathology findings and elevated immunoglobulin G4. This case highlights the complexities in diagnosis, the role of advanced imaging techniques and tissue sampling, and the lessons learned regarding managing this challenging clinical scenario.

Update on respiratory lesions in patients with IgG4-related autoimmune pancreatitis

We previously reported respiratory involvement in 25 patients with autoimmune pancreatitis, a pancreatic manifestation of IgG4-related disease that responds well to glucocorticoid treatment. However, whether all respiratory lesions in patients with autoimmune pancreatitis have genuine respiratory involvement is unclear. This study aimed to update respiratory lesions' clinical and radiological characteristics in patients with autoimmune pancreatitis. We retrospectively reviewed the clinical and radiological data of 74 consecutive patients diagnosed with autoimmune pancreatitis at Shinshu University Hospital and treated with glucocorticoid. Clinical features and chest high-resolution computed tomography findings before and after therapy were reviewed. Fifty-one patients (68.9%) had respiratory lesions. In 65 of the 74 patients, chest high-resolution computed tomography results were evaluated before and after treatment. Patients with IgG4-related disease and respiratory lesions showed significantly higher serum IgG4 levels and hypocomplementemia than those without respiratory lesions; they also had more affected organs. While most abnormal thoracic findings improved, 4 cases of 7 with reticular opacities and all 11 cases with emphysema did not improve. Therefore, these lesions with poor response to glucocorticoid treatment should not be considered due to respiratory involvement of autoimmune pancreatitis based on the current classification criteria for IgG4-related disease. Patients with autoimmune pancreatitis and respiratory lesions exhibited higher disease activity than those without. Most chest high-resolution computed tomography lesions were responsive to glucocorticoid treatment, whereas reticular opacities and emphysema were poorly responsive.

Obstructive Jaundice Mimicking Pancreatic Cancer: An Unusual Presentation of Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is an uncommon variant of chronic pancreatitis characterized by inflammatory changes within the pancreatic tissue triggered by autoimmune mechanisms. It is known to mimic pancreatic cancer due to its similar clinical and radiological presentations. We underline a case of a 55-year-old male who presented with weight loss, jaundice, and pruritus. Radiological imaging suggested a pancreatic mass, raising suspicion of malignancy. However, subsequent evaluation, absence of parenchymal tissue and lymphoplasmacytic cells on endoscopic ultrasound-guided biopsy, and elevated serum immunoglobulin G4 level resulted in the diagnosis of AIP. Our case emphasizes that AIP should be included in the differential diagnosis of obstructive jaundice, especially when clinical and radiological findings are inconclusive for pancreatic cancer.

An unusual occurrence of autoimmune pancreatitis after gam-Covid-Vac (Sputnik V): A case report and literature review

The safety profile of the Sputnik V vaccine is generally reassuring. Nevertheless, an enhanced risk of new-onset of immune-mediated diseases has been increasingly reported following the adenoviral-based Covid-19 vaccine, including inflammatory arthritis, Guillain-Barré syndrome, optical neuromyelitis, acute disseminated encephalomyelitis, subacute thyroiditis and acute liver injury as well as glomerulopathy. However, no case of autoimmune pancreatitis has been reported yet. Herein, we describe a case of type I autoimmune pancreatitis that may be due to the Sputnik V Covid-19 vaccine.

Misdiagnosis and delayed diagnosis of atypical autoimmune pancreatitis: Experience from clinical cases

Autoimmune pancreatitis (AIP) is a fibro-inflammatory disease characterized by inflammation and fibrosis of the pancreas. It is a systemic disease that can affect multiple organs, including the bile ducts, kidneys, lungs, and other organs. However, due to its complex presentation, AIP is often challenging to diagnose, and misdiagnosis with pancreatic tumors can occur. In our study, we reviewed three cases of atypical AIP where patients had normal serum IgG4 levels, leading to initial misdiagnosis with pancreatic tumors. Delayed diagnosis resulted in irreversible pathologies such as retroperitoneal fibrosis. All three patients had bile duct involvement, and imaging findings were similar to those of tumors, further complicating the diagnosis. The correct diagnosis was confirmed only after diagnostic therapy. Our study aims to raise awareness of atypical AIP and improve diagnostic efficiency by analyzing the clinical characteristics of these patients.

Immune Checkpoint Inhibitor-related Pancreatitis: A Case Series, Review of the Literature and an Expert Opinion

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various malignancies, but are associated with serious adverse events like pancreatitis. Current guidelines are limited to the first step in treating acute ICI-related pancreatitis with steroids but lack treatment advices for steroid dependent pancreatitis. We describe a case series of 3 patients who developed ICI-related pancreatitis with chronic features such as exocrine insufficiency and pancreatic atrophy at imaging. Our first case developed after treatment with pembrolizumab. The pancreatitis responded well after discontinuation of immunotherapy but imaging showed pancreatic atrophy and exocrine pancreatic insufficiency persisted. Cases 2 and 3 developed after treatment with nivolumab. In both, pancreatitis responded well to steroids. However during steroid tapering, pancreatitis recurred and the latter developed exocrine pancreatic insufficiency and pancreatic atrophy at imaging. Our cases demonstrate resemblances with autoimmune pancreatitis based on clinical and imaging findings. In line, both diseases are T-cell mediated and for autoimmune pancreatitis azathioprine is considered as maintenance therapy. Guidelines of other T-cell mediated diseases like ICI-related hepatitis suggest tacrolimus. After adding tacrolimus in case 2 and azathioprine in case 3, steroids could be completely tapered and no new episodes of pancreatitis have occurred. These findings support the idea that the treatment modalities for other T-cell mediated diseases are worthwhile options for steroid dependent ICI-related pancreatitis.

IgG4-Related Membranous Nephropathy with Acute Nephrotic Syndrome During Successful Steroid Maintenance Treatment for Type 1 Autoimmune Pancreatitis

BACKGROUND Immunoglobulin G4 (IgG4)-related diseases (IgG4-RD) are systemic fibroinflammatory diseases that can develop asynchronously in multiple organs. IgG4-related kidney disease (IgG4-RKD) is generally characterized by tubulointerstitial nephritis but can also manifest as membranous nephropathy without tubulointerstitial nephritis. IgG4-related membranous nephropathy can present as a phenotype of systemic disorders, including autoimmune pancreatitis-associated diabetes mellitus; however, its clinical features remain unclear. CASE REPORT A 56-year-old Japanese man presented to our university hospital with bilateral edema of his lower legs. He had received a diagnosis of type 1 autoimmune pancreatitis and associated diabetes mellitus 16 months prior. He was successfully treated with oral glucocorticoids 25 mg/day of prednisolone as an initial dose, followed by titration down to a maintenance dose (5 mg/day), without recurrence of autoimmune pancreatitis. The pancreas showed atrophy and required basal-bolus insulin therapy owing to insulin insufficiency. Massive proteinuria and hypoalbuminemia with nephrotic syndrome on examination led to a renal biopsy to investigate the etiology and diagnosis of IgG4-RKD. Methylprednisolone and cyclosporine A were successfully administered to ameliorate the proteinuria and control systemic IgG4-RD with IgG4-related membranous nephropathy. CONCLUSIONS Ig4-RKD occurred despite maintenance treatment with prednisolone monotherapy and was controlled with methylprednisolone and cyclosporine A. Measurement of clinical parameters, including proteinuria, was important, and a renal biopsy finally established the diagnosis of IgG4-RKD. IgG4-RKD can present with progressive glomerular lesions and can be latent in cases diagnosed with diabetic kidney disease, particularly in patients with insulin insufficiency.

Autoimmune pancreatitis associated with inflammatory bowel diseases: A retrospectively bidirectional case-control study in China

OBJECTIVES

Autoimmune pancreatitis (AIP) is a rare and enigmatic immune-mediated inflammatory disease. We aimed to investigate the prevalence, characteristics, and associated factors of AIP-inflammatory bowel disease (IBD) in China.

METHODS

A retrospective bidirectional case-control study was performed. The diagnoses of IBD and AIP were made based on the European Crohn's and Colitis Organization guidelines and the International Consensus Diagnostic Criteria. IBD controls were matched by age, sex, and IBD type at a ratio of 1:4, while AIP controls were matched by AIP types.

RESULTS

The age-standardized prevalence of AIP-IBD patients in the IBD and AIP population were 292.0 and 8151.93 per 100 000 population, respectively. IBD patients had a higher risk of AIP compared to non-IBD patients (odds ratio 8.4, 95% confidence interval 4.7-14.9, P < 0.0001), and AIP patients had a higher risk of developing IBD compared to the general population in China. The mean age at diagnosis of IBD and AIP was 34.83 years and 40.42 years. IBD was diagnosed before AIP in seven cases. The median total IBD and AIP duration was 43.5 months and 13.5 months. Use of mesalamine and tuberculosis were associated with AIP in IBD patients (P = 0.031). And fecal occult blood test was associated with IBD in AIP patients (P = 0.008).

CONCLUSIONS

Most AIP-IBD patients had ulcerative colitis and type 2 AIP. IBD patients are more likely to develop AIP compared to the general population, and vice versa. Use of mesalamine and tuberculosis infection were associated with AIP, and fecal occult blood test was associated with IBD.

Case report: Induction and maintenance of steroid-free remission with vedolizumab in a case of steroid-dependent autoimmune pancreatitis

Autoimmune pancreatitis responds well to corticosteroids in most instances. Additional immunosuppression or low-dose maintenance steroids may be necessary upon relapse. There is limited data on alternative strategies when these regiments fail or cause adverse reactions. We report a case of a middle-aged woman with autoimmune pancreatitis in whom tapering of prednisolone below the dose of 25mg per day resulted in relapse of symptoms and long-term steroid use led to development of steroid induced hyperglycaemia. Induction and maintenance of steroid-free remission was ultimately successful under vedolizumab therapy. Remission has been stable for over one year with reduced need for antidiabetic intervention. This is the first reported case of treatment of refractory autoimmune pancreatitis with vedolizumab. It highlights the overlap of immunological mechanisms within inflammatory diseases of the digestive tract and how knowledge of biological data can inform treatment decisions for individual cases. The demonstrated efficacy of vedolizumab and low risk of severe side effects warrant further investigation into its use in autoimmune pancreatitis.

Combined REGN-COV2 Antibody Therapy Immediately Prevented a Patient with Refractory Type 1 Autoimmune Pancreatitis from Contracting SARS-CoV-2 during the Sixth Wave in Japan

A 51-year-old man who had been receiving steroid therapy for type 1 autoimmune pancreatitis (AIP) for 3 years contracted coronavirus disease 2019 (COVID-19). As he had a high-grade fever and dry cough, and because his SpO2 level had dropped below 95% in the supine position, he was considered as being at a high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); therefore, he received combined REGN-COV2 antibody therapy. The patient's fever resolved immediately after this treatment, and he went into remission. A high cumulative steroid dose is associated with an increased susceptibility to infection. Early antibody cocktail therapy may be effective and rewarding for steroid-dependent type 1 AIP patients with a potential risk for SARS-CoV-2.

Clinical presentation and organ-based outcomes of Multifocal fibrosclerosis: A systematic review

Objectives

Multifocal fibrosclerosis is a rare disorder causing progressive fibrosis of multiple organ systems. Existing data on the disease show that there are multiple manifestations of the disease, with different outcomes. However, quantitative data are scarce, prompting the need for our investigation.

Method

A comprehensive systematic review was performed from inception to November 16, 2022, with the restriction of English language, not including review articles. Article screening and extraction was performed independently, and shortlisted articles were assessed for bias. Analysis was performed using SPSS Version 25 (IBM® SPSS® Statistics; Chicago, IL, USA). Data were presented as frequencies and percentages, with a confidence interval of 95%.

Result

This review included 134 patients, with 78 (58.2%) males. Mean age was 53.6 years and included two pediatric patients. The most common comorbidity was diabetes (9.7%). Prevalent presenting symptoms included pain (47.8%) and swelling (35.1%). A mean of 2.51 organs or anatomical sites was affected, retroperitoneum (64.2%) being most affected. The pancreas (30.0%) and digestive system (47.0%) were the organs/organ systems most affected. Patients had favorable outcomes in 79.1% of cases, 87.3% had no relapse, and 91.8% of patients survived the condition.

Conclusion

The findings in this study provide a quantitative measurement of the demographics, presentations, organ manifestations, and outcomes of multifocal fibrosclerosis. We found the disease to be prevalent in males in Japan or the United States, with the abdomen and its organs being commonly involved.

Activation of the aryl hydrocarbon receptor inhibits the development of experimental autoimmune pancreatitis through IL-22-mediated signaling pathways

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor expressed in hematopoietic and non-hematopoietic cells. Activation of the AhR by xenobiotics, microbial metabolites, and natural substances induces immunoregulatory responses. Autoimmune pancreatitis (AIP) is a chronic fibroinflammatory disorder of the pancreas driven by autoimmunity. Although AhR activation generally suppresses pathogenic autoimmune responses, the roles played by the AhR in AIP have been poorly defined. In this study, we examined how AhR activation affected the development of experimental AIP caused by the activation of plasmacytoid dendritic cells producing IFN-α and IL-33. Experimental AIP was induced in MRL/MpJ mice by repeated injections of polyinosinic-polycytidylic acid. Activation of the AhR by indole-3-pyruvic acid and indigo naturalis, which were supplemented in the diet, inhibited the development of experimental AIP, and these effects were independent of the activation of plasmacytoid dendritic cells producing IFN-α and IL-33. Interaction of indole-3-pyruvic acid and indigo naturalis with AhRs robustly augmented the production of IL-22 by pancreatic islet α cells. The blockade of IL-22 signaling pathways completely canceled the beneficial effects of AhR ligands on experimental AIP. Serum IL-22 concentrations were elevated in patients with type 1 AIP after the induction of remission with prednisolone. These data suggest that AhR activation suppresses chronic fibroinflammatory reactions that characterize AIP via IL-22 produced by pancreatic islet α cells.

A Clinical and Pathophysiological Overview of Intestinal and Systemic Diseases Associated with Pancreatic Disorders: Causality or Casualty?

The relationship between chronic intestinal disease, including inflammatory bowel disease (IBD) and celiac disease (CelD), and pancreatic disorders has been little investigated. Although an increased risk of acute pancreatitis (AP), exocrine pancreatic insufficiency with or without chronic pancreatitis, and chronic asymptomatic pancreatic hyperenzymemia have been described in these patients, the pathogenetic link remains unclear. It may potentially involve drugs, altered microcirculation, gut permeability/motility with disruption of enteric-mediated hormone secretion, bacterial translocation, and activation of the gut-associated lymphoid tissue related to chronic inflammation. In addition, the risk of pancreatic cancer seems to be increased in both IBD and CelD patients with unknown pathogenesis. Finally, other systemic conditions (e.g., IgG4-related disease, sarcoidosis, vasculitides) might affect pancreatic gland and the intestinal tract with various clinical manifestations. This review includes the current understandings of this enigmatic association, reporting a clinical and pathophysiological overview about this topic.

Steroid therapy has an acceptable role as the initial treatment in autoimmune pancreatitis patients with pancreatic cyst formation: Based on a Japanese nationwide study

BACKGROUND

We attempted to determine the indications and limitations of steroid therapy as the first-line therapy in patients with autoimmune pancreatitis (AIP) with cyst formation (ACF).

METHODS

This Japanese multicenter survey was conducted to examine the merits/demerits of steroid treatment as the initial therapy for ACF.

RESULTS

Data of a total of 115 patients with ACF were analyzed. Complete remission was achieved in 86% (86/100) of patients who had received steroid treatment, but only 33.3% (5/15) of patients who had not received steroids. Relapse after the remission (n = 86) occurred in 7.6% (6/86) of patients who had received steroid therapy, but 40% (2/5) of patients who had not received steroid therapy. Multivariate analysis identified adoption of the wait and watch approach without steroid treatment (odds ratio = 0.126, P < .001) as a significant and independent negative predictor of remission of ACF. As for predictors of relapse, the presence of varix (odds ratio = 5.83, P = .036) was identified as an independent risk factor.

CONCLUSION

Steroid therapy plays an important role as first-line therapy in AIP patients with pancreatic cyst formation, however, varix formation, besides the diameter of the cyst(s), is a risk factor for refractoriness to steroid therapy.

A Case of Autoimmune Pancreatitis Presenting As Alcohol-Induced Necrotizing Pancreatitis

Autoimmune pancreatitis (AIP) is an inflammatory condition of the pancreas, commonly characterized by elevated levels of immunoglobulin G (IgG) 4. Diagnosis of this condition can be challenging in patients with risk factors for other pancreatitis etiologies and requires a comprehensive approach utilizing clinical, radiologic, and laboratory findings. Here, we present a case of an individual with a history of multiple prior hospitalizations for alcoholic pancreatitis, who presented with symptoms of abdominal pain, nausea, and vomiting. Computed tomography (CT) imaging revealed intra-abdominal abscesses and findings consistent with pancreatitis. Further laboratory results revealed elevated lipase and IgG4 levels, indicating AIP as the underlying cause. This case highlights the importance of considering AIP as a differential diagnosis in individuals presenting with pancreatic disease.

Immunoglobulin G4-Seronegative Autoimmune Cholangiopathy With Pancreatic and Hepatic Involvement Mimicking as Primary Sclerosing Cholangitis

Immunoglobulin G4-seronegative autoimmune cholangiopathy is a rare cause of biliary strictures. We describe a 27-year-old man presenting with elevated liver enzymes, recurrent cholangitis/bacteremia, biliary strictures, and normal immunoglobulin G4 levels, who was initially diagnosed with primary sclerosing cholangitis, and later listed for transplantation for recurrent bacteremia. Subsequent surveillance imaging demonstrated morphologic changes consistent with biliary strictures and autoimmune pancreatitis. Initiating corticosteroids resulted in liver enzyme normalization and stricture improvement. Diagnosing seronegative autoimmune cholangiopathy remains challenging given similar presentation to primary sclerosing cholangitis. This case highlights importance of a wide differential for biliary strictures, with increased suspicion in those developing pancreatic changes in this setting.

Synchronous Pancreatic Masses

Any mass lesion in the pancreas usually raises the possibility of undiagnosed pancreatic cancer. With the advancement of imaging modalities, we are seeing an increasing number of incidental findings, some of which may be clinically significant. When dealing with incidental pancreatic findings, it is critical to keep a broad differential in mind in addition to ruling out pancreatic malignancy. We present 3 rare cases of patients with 2 or more synchronous solid masses in the pancreas caused by pancreatic cancer, type 1 autoimmune pancreatitis, and sarcoidosis.

Concomitant Pancreatic Ductal Adenocarcinoma and Type 1 Autoimmune Pancreatitis: A Potential Issue in the Diagnosis of Carcinoma by Endoscopic Ultrasound-guided Fine-needle Biopsy

We herein report a 64-year-old man with concomitant pancreatic ductal adenocarcinoma (PDAC) and type 1 autoimmune pancreatitis (AIP). An endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) from the pancreatic head mass revealed level 2 histology of AIP and atypical glands. We diagnosed definitive focal AIP using the clinical diagnostic criteria. Computed tomography revealed that the pancreatic mass had not been reduced by steroid therapy. Surgery was performed after a histological PDAC diagnosis was made via a transpapillary biliary biopsy. The resected specimen revealed PDAC associated with AIP. It is important to consider the cooccurrence of PDAC and AIP even if the histological diagnosis via an EUS-FNB is AIP.

Autoimmune pancreatitis – a surgical mistake?

Autoimmune pancreatitis is a specific type of chronic pancreatitis. Its clinical manifestation mimics pancreatic cancer. A multidisciplinary approach is necessary to establish the correct diagnosis. Autoimmune pancreatitis can be diagnosed on the basis of symptomatology, imaging methods, endoscopy, serology and histopathological examination. There are two different forms of autoimmune pancreatitis – type 1 and type 2. Type 1 is lymphoplasmacytic sclerosing pancreatitis and type 2 is idiopathic centroductal sclerosing pancreatitis. The disease most often takes a chronic form with acute exacerbations. In this paper we present two case reports of patients operated on for suspected malignancy of the pancreas, who were subsequently diagnosed with autoimmune pancreatitis based on histopathological examination. The aim of this communication is to point out the diagnostic pitfalls of this disease. Surgical treatment is not considered as a standard therapeutic method according to the current guidelines.

Characteristics of mass-forming autoimmune pancreatitis commonly misdiagnosed as a malignant tumor

Objective

This study aimed to explore the clinical characteristics and differential diagnosis of patients with autoimmune pancreatitis (AIP) and pancreatic cancer to prevent misdiagnosis and mistreatment.

Methods

The clinical data of patients with AIP with suspected pancreatic or bile duct malignancy and pancreatic cancer were retrospectively analyzed. The risk factors and the diagnostic value of IgG4 and Tbil levels before treatment for AIP was investigated. Moreover, the imaging features and response to hormone therapy were analyzed.

Results

AIP was commonly observed in men. Compared to patients with pancreatic cancer, the incidence of poor appetite and weight loss and carbohydrate antigen 19-9 (CA19-9) level was lower in patients with AIP, while the immunoglobulin G4 (IgG4) level was higher (p < 0.05). After treatment, the IgG4 and CA19-9 levels in patients with AIP were decreased (p < 0.001). IgG4 level before treatment (OR = 2.452, 95%CI: 1.180-5.096, P = 0.016) and total bilirubin (Tbil) level before treatment (OR = 0.992, 95%CI: 0.985-0.998, P = 0.013) were independent risk factors of AIP. Furthermore, the diagnostic value of IgG4 level before treatment, Tbil level before treatment, IgG4/Tbil before treatment, and a combination of these indicators was high. Moreover, 15 (68.18%) patients with AIP had space-occupying lesions of the pancreas, and 16 (72.73%) had autoimmune cholangitis. Most patients with AIP were sensitive to hormone therapy.

Conclusions

The Tbil and IgG4 levels, imaging findings, and hormone therapy reactivity could differentiate AIP from pancreatic cancer. A combination of IgG4, Tbil, and IgG4/Tbil before treatment might be a promising diagnostic biomarker for AIP.

Is Surgery in Autoimmune Pancreatitis Always a Failure?

Autoimmune pancreatitis is a rare form of chronic pancreatitis of presumed autoimmune etiology. Due to significant overlap in clinical and imaging characteristics, misdiagnosis as a pancreatic malignancy is common. As a result, a significant number of patients undergo a major pancreatic resection, associated with considerable morbidity, for a disease process that generally responds well to corticosteroid therapy. In the past ten years, important advances have been made in understanding the disease. Several diagnostic criteria have been developed to aid in diagnosis. Despite this, pancreatic resection may still be required in a subset of patients to reliably exclude pancreatic malignancy and establish a definite diagnosis of autoimmune pancreatitis. This article aimed to define the role of surgery in autoimmune pancreatitis, if any. For this purpose, published case series of patients with a diagnosis of autoimmune pancreatitis, based on the histopathological examination of surgical specimens, were reviewed and patients' clinical, radiological and serological details were assessed. At the end, histopathologic examinations of patients who underwent pancreatic resection at our department in the last 10 years were retrospectively reviewed in order to identify patients with autoimmune pancreatitis and assess their clinical characteristics.

Autoimmune pancreatitis: A bibliometric analysis from 2002 to 2022

Background/Objectives

Autoimmune pancreatitis (AIP) is a distinct form of pancreatic inflammatory disease that responds well to glucocorticoid therapy. Knowledge on AIP has rapidly evolved over the past two decades. Based on bibliometric analysis, this study aimed to assess the research status of AIP over the past two decades and determine the research focus and emerging topics.

Methods

AIP-related publications published between January 1, 2002, and June 6, 2022, were retrieved from the Web of Science Core Collection. Bibliometric data were analyzed using HisCite, VOSviewer, CiteSpace, and bibliometrix package. Annual output, leading countries/regions, active institutions and authors, core journals and references, and keywords of AIP were evaluated.

Results

Overall, 1,772 publications were retrieved from 501 journals by 6,767 authors from 63 countries/regions. Japan published articles on AIP the most (n=728, 41.1%), followed by the United States (n=336, 19%), Germany (n=147, 8.3%), China (n=127, 7%), and Italy (n=107, 6%). The top three most prolific authors were Terumi Kamisawa from Tokyo Metropolitan Komagome Hospital (n=117), Kazuichi Okazaki from Kansai Medical University (n=103), and Shigeyuki Kawa from Matsumoto Dental University (n=94). Pancreas was the most productive journal regarding AIP research (n=95), followed by the Journal of Gastroenterology (n=67), Internal Medicine (n=66), Pancreatology (n=63), and World Journal of Gastroenterology (n=62). "Diagnosis" was the most mentioned keyword. "Risk," "malignancy," "outcome," "22-gauge needle," and "fine-needle aspiration" were recognized as emerging topics.

Conclusion

Japan was the leading country in AIP research. Research papers were mainly published in specialized journals. Diagnosis was the research focus. Long-term outcomes and pancreatic tissue acquisition were recognized as research frontiers for AIP.

Mass-forming immunoglobulin G4-related cholangitis with atypical pancreatic lesions: a case report of difficult diagnosis

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a systemic immune-mediated fibroinflammatory disease that results in the tissue destruction of multiple organs. IgG4-RD is often underdiagnosed or misdiagnosed as malignant, infectious, or other inflammatory disorder.

CASE PRESENTATION

We describe a 56-year-old woman presented with jaundice and weight loss. Radiological imaging showed common hepatic duct wall thickening and nodular lesions in the pancreas, which was highly suspicious of malignancy. However, she was contraindicated for biopsy; hence, the diagnosis of IgG4-RD was made based on her high serum IgG4 level, multiorgan involvement, and steroid response. The effect of steroid therapy was significant, although the disease relapsed during the maintenance treatment. The dosage of steroid was re-increased, and the patient was under close follow-up.

CONCLUSIONS

The diagnosis of IgG4-RD is challenging due to its diverse manifestations. Therefore, a careful systematic assessment is necessary to improve the accuracy of IgG4-RD diagnosis, and a close follow-up is important to monitor the disease development as well as adjust the treatment strategy accordingly.

[Differential diagnosis of IgG4-related disease]

IgG4-related disease is a chronic autoimmune fibro-inflammatory disease characterized by the presence of lymphoplasmacytic infiltrate, storiform fibrosis, obliterating phlebitis, increased number of IgG4+ cells in tissue, and, in most cases, an elevated serum IgG4 level. This disease often affects the pancreas, salivary glands and lymph nodes, but can involve almost any tissue. Its etiology is still unclear, the central role in the pathogenesis belongs to B-lymphocytes, T2-helpers, interleukins 1-β, 4, 5, 10, 13 and tumor growth factor 1-β. The ambiguous clinical picture and frequent simultaneous involvement of several organs make it difficult to diagnose, so biopsy plays a leading role in making a diagnosis. The characteristic microscopic picture, the presence of certain populations of lymphocytes are key criteria in establishing the correct diagnosis.

Disruption of the intestinal barrier exacerbates experimental autoimmune pancreatitis by promoting the translocation of Staphylococcus sciuri into the pancreas

Autoimmune pancreatitis (AIP) and IgG4-related disease (IgG4-RD) are new disease entities characterized by enhanced IgG4 antibody responses and involvement of multiple organs, including the pancreas and salivary glands. Although the immunopathogenesis of AIP and IgG4-RD is poorly understood, we previously reported that intestinal dysbiosis mediates experimental AIP through the activation of IFN-α- and IL-33-producing plasmacytoid dendritic cells (pDCs). Because intestinal dysbiosis is linked to intestinal barrier dysfunction, we explored whether the latter affects the development of AIP and autoimmune sialadenitis in MRL/MpJ mice treated with repeated injections of polyinosinic-polycytidylic acid [poly (I:C)]. Epithelial barrier disruption was induced by the administration of dextran sodium sulfate (DSS) in the drinking water. Mice co-treated with poly (I:C) and DSS, but not those treated with either agent alone, developed severe AIP, but not autoimmune sialadenitis, which was accompanied by the increased accumulation of IFN-α- and IL-33-producing pDCs. Sequencing of 16S ribosomal RNA revealed that Staphylococcus sciuri translocation from the gut to the pancreas was preferentially observed in mice with severe AIP co-treated with DSS and poly (I:C). The degree of experimental AIP, but not of autoimmune sialadenitis, was greater in germ-free mice mono-colonized with S. sciuri and treated with poly (I:C) than in germ-free mice treated with poly (I:C) alone, which was accompanied by the increased accumulation of IFN-α- and IL-33-producing pDCs. Taken together, these data suggest that intestinal barrier dysfunction exacerbates AIP through the activation of pDCs and translocation of S. sciuri into the pancreas.

Revisiting the cytologic features of autoimmune pancreatitis: An institutional experience

BACKGROUND

Autoimmune pancreatitis (AIP) is a known mimicker of pancreatic ductal adenocarcinoma both clinically and radiologically. In this study, the authors present their institutional experience in diagnosing AIP on cytology and correlate results with the histologic findings.

METHODS

A 14-year computerized search for patients who had histologically confirmed AIP with concurrent or prior cytology was performed. Clinical data, cytology findings, and surgical pathology results were reviewed for analysis.

RESULTS

Eighteen patients were identified. The patients showed a male predominance, with a mean age of 59 years. Jaundice, weight loss, and abdominal pain were the most common clinical presentation. Five of 12 patients who were tested for serum immunoglobulin G4 had elevated levels. Cytologic findings of 16 cases that were available for review showed markedly inflamed fibrous stroma (54%) and cytologic atypia (50%). The final cytologic diagnoses were suspicious for adenocarcinoma (n = 1), atypical (n = 8), and benign/negative (n = 9). The corresponding surgical pathology diagnoses were classified as type 1 (n = 10), type 2 (n = 6), and AIP, not otherwise specified (n = 2). All type 2 AIP cases had at least atypical cytologic diagnoses, with one called suspicious for adenocarcinoma and another called adenocarcinoma at the time of rapid on-site evaluation. In contrast, eight of 10 type 1 AIP cases were negative/benign, and two of 10 were atypical. In these two atypical cases, the possibility of AIP was raised because of the presence of inflamed stroma.

CONCLUSION

AIP is a pitfall in cytology because moderate-to-marked atypia can be present, especially in type 2 AIP. Because atypia can be severe, the presence of cellular fibrous stroma with lymphocytic stromal infiltrates and the integration of serum immunoglobulin G4 levels could be helpful in avoiding diagnostic overcall in AIP.

Artificial Intelligence in Endoscopic Ultrasound for Pancreatic Cancer: Where Are We Now and What Does the Future Entail?

Pancreatic cancer is a highly lethal disease associated with significant morbidity and mortality. In the United States (US), the overall 5-year relative survival rate for pancreatic cancer during the 2012-2018 period was 11.5%. However, the cancer stage at diagnosis strongly influences relative survival in these patients. Per the National Cancer Institute (NCI) statistics for 2012-2018, the 5-year relative survival rate for patients with localized disease was 43.9%, while it was 3.1% for patients with distant metastasis. The poor survival rates are primarily due to the late development of clinical signs and symptoms. Hence, early diagnosis is critical in improving treatment outcomes. In recent years, artificial intelligence (AI) has gained immense popularity in gastroenterology. AI-assisted endoscopic ultrasound (EUS) models have been touted as a breakthrough in the early detection of pancreatic cancer. These models may also accurately differentiate pancreatic cancer from chronic pancreatitis and autoimmune pancreatitis, which mimics pancreatic cancer on radiological imaging. In this review, we detail the application of AI-assisted EUS models for pancreatic cancer detection. We also highlight the utility of AI-assisted EUS models in differentiating pancreatic cancer from radiological mimickers. Furthermore, we discuss the current limitations and future applications of AI technology in EUS for pancreatic cancers.

Reducing relapse through maintenance steroid treatment can decrease the cancer risk in patients with IgG4-sclerosing cholangitis: Based on a Japanese nationwide study

OBJECTIVE

IgG4-related sclerosing cholangitis (IgG4-SC) is recognized as a benign steroid-responsive disease; however, little is known about the risk of development of cancer in patients with IgG4-SC and about how to counter this risk.

DESIGN

We conducted a retrospective review of the data of 924 patients with IgG4-SC selected from a Japanese nationwide survey. The incidence, type of malignancy, and risk of malignancy in these patients were examined. Then, the standardized incidence ratio (SIR) of cancer in patients with IgG4-SC was calculated.

RESULTS

Relapse was recognized in 19.7% (182/924) of patients, and cancer development was noted in 15% (139/924) of patients. Multivariate analysis identified only relapse as an independent risk factor for the development of cancer. In most of these patients with pancreato-biliary cancer, the cancer developed within 8 years after the diagnosis of IgG4-SC. The SIR for cancer after the diagnosis of IgG4-SC was 12.68 (95% confidence interval [CI] 6.89-8.79). The SIRs of cancers involving the biliary system and pancreas were 27.35 and 18.43, respectively. The cumulative survival rate was significantly better in the group that received maintenance steroid treatment (MST) than in the group that did not; thus, MST influenced the prognosis of these patients.

CONCLUSION

Among the cancers, the risk of pancreatic and biliary cancers is the highest in these patients. Because of the elevated cancer risk, surveillance after the diagnosis and management to prevent relapse are important in patients with IgG4-SC to reduce the risk of development of cancer.

Autoimmune Pancreatitis: From Pathogenesis to Treatment

Autoimmune pancreatitis (AIP) is a rare disease. The diagnosis of AIP is difficult and should be made by a comprehensive evaluation of clinical, radiological, serological, and pathological findings. Two different types of AIP have been identified: autoimmune pancreatitis type 1 (AIP-1), which is considered a pancreatic manifestation of multiorgan disease related to IgG4, and autoimmune pancreatitis type 2 (AIP-2), which is considered a pancreas-specific disease not related to IgG4. Although the pathophysiological conditions seem to differ between type 1 and type 2 pancreatitis, both respond well to steroid medications. In this review, we focused on the pathogenesis of the disease to develop a tool that could facilitate diagnosis and lead to the discovery of new therapeutic strategies to combat autoimmune pancreatitis and its relapses. The standard therapy for AIP is oral administration of corticosteroids. Rituximab (RTX) has also been proposed for induction of remission and maintenance therapy in relapsing AIP-1. In selected patients, immunomodulators such as azathioprine are used to maintain remission. The strength of this review, compared with previous studies, is that it focuses on the clear difference between the two types of autoimmune pancreatitis with a clearly delineated and separate pathogenesis. In addition, the review also considers various therapeutic options, including biologic drugs, such as anti-tumor necrosis factor (TNF) therapy, a well-tolerated and effective second-line therapy for AIP type 2 relapses or steroid dependence. Other biologic therapies are also being explored that could provide a useful therapeutic alternative to corticosteroids and immunosuppressants, which are poorly tolerated due to significant side effects.

Autoimmune Pancreatitis with Massive Ascites and Multiple Pancreatic Cysts Successfully Treated with Prednisolone: A Case Report

A 64-year-old man with a history of diabetes and gallstones was admitted to our institution with suspected pancreatic malignancy. Computed tomography (CT) revealed multiple pancreatic cysts and massive ascites, and endoscopic ultrasonography (EUS) revealed a 28×27-mm hypoechoic mass in the pancreatic head. An EUS-guided fine-needle aspiration biopsy was performed, and there were no malignant findings. Based on the test results and imaging findings, type 1 autoimmune pancreatitis was suspected. The patient was administered 30 mg of prednisolone daily. After 11 days, CT revealed that the pancreatic cysts and ascites had reduced in size.

Diffuse Involvement of Pancreas is not Always Autoimmune Pancreatitis

RATIONALE AND OBJECTIVES

To determine the prevalence of diffuse involvement of pancreas and to identify the findings of malignancies using enhancement computed tomography (CT).

MATERIALS AND METHODS

A total of 1,0249 patients performed enhancement CT in our hospital over 62 months were investigated and the final study cohort includes 245 patients (170 males, 75 females; mean age, 56.94 ± 12.17 years). The reference standard is the final clinical/pathological diagnosis. The lesion-to-aorta enhancement ratio (LAR) on the pancreatic arterial phase, portal phase and delayed phase (DP) and the traditional CT findings were evaluated. Intergroup comparisons between malignancies and non-malignancies lesions were performed. Univariate and multivariate analyses were conducted to identify findings predicting malignancies.

RESULTS

The prevalence of malignancy was 45.3% (111/245) of diffuse enlargement of pancreas. All benign lesions were autoimmune pancreatitis 54.7% (n = 134). The most common malignant lesion was pancreatic ductal adenocarcinoma (n = 88, 35.9%). Other rare lesions with malignant potential included pancreatic neuroendocrine tumor (n = 11, 4.5%), lymphoma (n = 4, 1.6%), metastasis (n = 4, 1.6%), solid pseudopapillary neoplasm (n = 3, 1.2%) and acinar cell carcinoma (n = 1, 0.4%). Residual normal pancreas parenchyma, heterogeneity, short axis (cut-off value, 3.15 cm) and LAR_DP (cut-off value, 0.75) were independent predictors of malignancies. When the above predictors were combined, a sensitivity of 94.2%, a specificity of 90.8% were attained.

CONCLUSION

Diffuse involvement of the pancreas is rare and is not a specific sign of autoimmune pancreatitis, and it is associated with a wide spectrum of malignant conditions. Dynamic enhancement CT is helpful to identifying malignancies.

Evaluating the role of endoscopic ultrasound in pancreatitis

INTRODUCTION

Endoscopic ultrasound (EUS) provides high-resolution images of both pancreatic parenchyma and duct and therefore is an integral component of evaluating and treating patients with pancreatitis and its complications. The development of enhanced EUS imaging techniques and newer EUS-specific accessories has expanded the diagnostic and therapeutic role of EUS in patients with acute and chronic pancreatitis (CP).

AREAS COVERED

This review discusses the current diagnostic and therapeutic role of EUS in acute pancreatitis (AP), CP, and autoimmune pancreatitis (AIP).

EXPERT OPINION

EUS plays a vital role in patients with AP by confirming the presence of common bile duct (CBD) stones in patients with acute biliary pancreatitis and intermediate probability of CBD stones. It plays an important role in the etiological evaluation of patients with idiopathic acute and recurrent pancreatitis. EUS is also an essential modality for diagnosing and managing pancreatico-biliary as well as gastroduodenal complications associated with CP. EUS-guided FNB using newer generation core biopsy needles has made possible accurate diagnosis of AIP by providing tissue samples with preserved architecture.

The role of serological biomarkers in the diagnosis and management of autoimmune pancreatitis

INTRODUCTION

Autoimmune pancreatitis (AIP) is a fibroinflammatory disease of the pancreas. Type 1 AIP is the pancreatic manifestation of a systemic IgG4-related disease and is associated with serum elevation of IgG4, tissue infiltration of IgG4-positive plasma cells, and multiorgan involvement. Although serum IgG4 elevation is considered a useful diagnostic tool, the concomitant presence of more diagnostic criteria is needed to achieve diagnosis. No other biomarkers have been approved in clinical practice in type 1 AIP. Type 2 AIP is a pancreatic-specific disease associated with inflammatory bowel disease. No specific biomarkers for type 2 AIP have been identified.

AREAS COVERED

The role of serum IgG4 in the diagnosis, management and follow-up of patients with type 1 AIP. Moreover, data on other emerging biomarkers for type 1 and 2 AIP have been reported.

EXPERT OPINION

The diagnosis of AIP is challenging in clinical practice, especially for focal forms without multiorgan involvement, where distinction from pancreatic cancer can be difficult. Despite the strong association with type 1 AIP, serum IgG4 should only be measured when the suspicion for the disease is high, considering its limited sensitivity. New biomarkers with high diagnostic yield for both type 1 and type 2 AIP are needed.

Black pleural effusion caused by a pancreaticopleural fistula associated with autoimmune pancreatitis: A case report

RATIONALE

Black pleural effusion is a rare medical condition and a diagnostic marker. Pancreaticopleural fistula is one of the causes of black pleural effusion. Thus far, black pleural effusions caused by pancreaticopleural fistulae have mostly been reported in patients with alcohol-induced chronic pancreatitis. In this report, we present a case of black pleural effusion caused by a pancreaticopleural fistula associated with autoimmune pancreatitis.

PATIENT CONCERNS AND DIAGNOSIS

A 59-year-old female without a history of alcohol drinking presented to our hospital with a chief complaint of dyspnea, as well as chest and back discomfort. She had left pleural effusion, and thoracentesis showed black pleural effusion. Computed tomography revealed the presence of encapsulated fluid from the pancreatic tail to the left pleural cavity, which was diagnosed as a pancreaticopleural fistula. It also showed diffuse pancreatic swelling. Serum testing showed a high IgG4 level (363 mg/dL). These findings led to the diagnosis of autoimmune pancreatitis.

INTERVENTIONS AND OUTCOME

The patient underwent endoscopic pancreatic sphincterotomy and pancreatic duct stent placement and received treatment with steroids. After treatment, there was no further accumulation of pleural effusion observed.

CONCLUSION

This is the first report of black pleural effusion due to a pancreaticopleural fistula associated with autoimmune pancreatitis. The characteristic appearance of black pleural effusion may assist diagnosis. We report this case to emphasize that autoimmune pancreatitis can be a cause of black pleural effusion.

Prevalence and clinical features of patients with autoimmune pancreatitis and inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Autoimmune pancreatitis (AIP) and inflammatory bowel disease (IBD) are categorized into immune-mediated inflammatory disorders (IMIDs). While AIP is a pancreato-biliary IMID with an increased incidence and prevalence among patients with IBD, its features are still unclear. This systematic review and meta-analysis aims to assess the prevalence and clinical characteristics of AIP-IBD patients.

METHODS

Electronic databases were searched to identify observational studies assessing AIP and IBD. The primary outcome was the prevalence of IBD among AIP patients, and vice versa. Secondary outcomes included clinical findings and outcomes of each IMID in AIP-IBD patients. The pooled rate of each outcome was determined using a random effects model.

RESULTS

For primary outcomes, 40 observational studies with 4031 AIP patients were included and the pooled prevalence of IBD was 10.5% (95% CI 7.2-15.0%). Meanwhile, five studies with 10,551 IBD patients were included and the pooled prevalence of AIP was 0.6% (95% CI 0.2-1.9%). For secondary outcomes, 53 observational studies with 469 AIP-IBD patients were assessed. The rates of type 2 AIP and ulcerative colitis were 79.2% (95% CI 69.1-86.6%) and 74.8% (95% CI 68.2-80.4%), respectively. We also demonstrated AIP-IBD patients were at a significant increased risk of AIP recurrence and colectomy compared with patients with either AIP or IBD (RR = 1.9, 95% CI 1.1-3.1 and P = 0.014 and RR = 3.7, 95% CI 1.9-6.9, P < 0.001, respectively).

CONCLUSIONS

Our meta-analysis reported the prevalence of AIP-IBD patients and demonstrated patients with both IMIDs had a high risk of poor outcomes.

Accuracy and clinical outcomes of pancreatic EUS-guided fine-needle biopsy in a consecutive series of 852 specimens

Background and Objectives:

Pancreatic EUS-guided fine needle biopsy (EUS-FNB) is increasingly used. Accuracy of EUS-FNB, particularly for benign diseases, utility of additional EUS-FNB if malignancy is suspected but initial diagnosis is inconclusive, and complication rate are not fully elucidated. We evaluated operating characteristics of EUS-FNB overall and for different diagnostic categories, value of additional EUS-FNB if malignancy is suspected but initial diagnosis is inconclusive, and frequency and type of complications.

Methods:

A retrospective tertiary single-center study including 852 consecutive pancreatic SharkCore EUS-FNBs from 723 patients between 2015 and 2020. EUS-FNB diagnoses were applied according to Papanicolaou Society's system and each category was further subcategorized.

Results:

Sufficient tissue cylinders for a histologic diagnosis were obtained in 93.4% (796/852). Accuracy was overall, for malignant, and benign entities 85.6% (confidence interval [CI]: 83.2%–87.9%), 88.3% (CI: 85.9%–90.4%), and 94% (CI: 92.2%–95.5%). Sensitivity and accuracy of EUS-FNB for autoimmune pancreatitis (AIP) (n = 15) was 83.3% (CI: 58.6%–96.4%) and 99.2% (CI: 98.3%–99.7%). Of patients in whom malignancy was suspected but initial EUS-FNB diagnosis was inconclusive, 7.3% (53/723) underwent one or two additional EUS-FNBs, and in 54.7% (29/53) of these, a malignant diagnosis was established. The frequency of hospitalization following EUS-FNB was 4.7%, with 0.2% (n = 2) incidents needing active intervention.

Conclusions:

We found a high accuracy of pancreatic EUS-FNB across all diagnostic categories including rare entities, such as AIP. In patients with a clinical suspicion of malignancy, additional EUS-FNB resulted in a conclusive diagnosis in more than half of cases. Complications necessitate hospitalization in almost 5%, but the majority are self-limiting.

IgG4-Related Pancreato-Biliary Disease in the Disguise of Malignancy

The Immunoglobulin G4-related disease (IgG4-RD) is a multisystem inflammatory condition. Pancreaticobiliary manifestations often present as mass lesions that mimic malignancies. The diagnosis is confirmed by histopathological examination, that shows lymphoplasmacytic infiltration, storiform fibrosis, obliterative phlebitis, and positive immunohistochemistry for IgG4. We encountered 3 such patients in a tertiary care hospital in India. Two patients presented with obstructive jaundice and the third with pain abdomen. They had resectable lesions involving the pancreatic head, the right hepatic duct, and gallbladder fundus, respectively, on imaging. Tumor markers were not significantly elevated in any of them. All 3 patients underwent radical surgeries, suspecting malignancy. Surgical specimens showed typical features of IgG4-RD on histomorphology. Serum IgG4 level was elevated in first 2 patients but was normal in sclerosing cholecystitis patient. To conclude, IgG4-RD is a malignant mimicker; hence, on clinical suspicion, liberal attempts for tissue diagnosis may avoid radical surgeries.

The Impact of Pancreatic Exocrine Diseases on the β-Cell and Glucose Metabolism-A Review with Currently Available Evidence

Pancreatic exocrine and endocrine dysfunctions often come together in the course of pancreatic diseases as interdependent manifestations of the same organ. However, the mechanisms underlying the bidirectional connection of the exocrine and endocrine pancreas are not fully understood. In this review, we aimed to synthetize the current knowledge regarding the effects of several exocrine pancreatic pathologies on the homeostasis of β-cells, with a special interest in the predisposition toward diabetes mellitus (DM). We focused on the following pancreatic exocrine diseases: chronic pancreatitis, acute pancreatitis, cystic fibrosis, pancreatic cancer, pancreatic resections, and autoimmune pancreatitis. We discuss the pathophysiologic mechanisms behind the impact on β-cell function and evolution into DM, as well as the associated risk factors in progression to DM, and we describe the most relevant and statistically significant findings in the literature. An early and correct diagnosis of DM in the setting of pancreatic exocrine disorders is of paramount importance for anticipating the disease's course and its therapeutical needs.