International consensus diagnostic criteria for autoimmune pancreatitis: guidelines of the International Association of Pancreatology

Pancreatic Ductal Adenocarcinoma with Autoimmune Pancreatitis: A Case Report and Literature Review

A 50-year-old man was diagnosed with type 1 autoimmune pancreatitis (AIP) following endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and a histopathological examination. After six months of untreated follow-up, the serum IgG4 level decreased, and the diffuse pancreatic enlargement improved; however, a pancreatic head mass became apparent. EUS-FNA of this mass revealed pancreatic ductal adenocarcinoma (PDAC) with IgG4-positive plasma cells. In addition, the resected specimen revealed PDAC, without any features of AIP. After pancreatoduodenectomy, AIP did not recur. The development of AIP in this case could be related to paraneoplastic syndrome.

CT surveillance for type 1 autoimmune pancreatitis: cumulative radiation dose and diagnostic performance for disease relapse

OBJECTIVES

Long-term follow-up is essential for type 1 autoimmune pancreatitis (AIP) patients due to high relapse rates. The cumulative radiation dose from repeated CT scans during follow-up should not be ignored. We aim to investigate the cumulative radiation dose in AIP patients undergoing CT surveillance and the diagnostic performance of CT in detecting disease relapse. The diagnostic performance of MRI from a secondary cohort during the same period was also investigated.

METHODS

This retrospective single-institutional study included 247 type 1 AIP patients with one or more follow-up CT scans, and 120 patients with MR follow-ups. Four metrics were utilized to report the radiation dose, including the volume computed tomography dose index, the dose length product, size-specific dose estimate and effective dose. The diagnostic performance for AIP relapse was assessed, taking the final clinical diagnosis in retrospect as the reference standard.

RESULTS

With a median 2.3-year follow-up period, AIP patients followed up with CT exhibited a median cumulative radiation dose of 37.5 mSv. 11.3% of patients have accumulated doses exceeding 100 mSv. For the 169 patients followed over a year, 30.8% sustained an average annual radiation dose surpassing 20 mSv. The sensitivity/specificity/accuracy of CT for detecting abdominal organ relapse was 64.1%/99.6%/97.0%. For AIP patients followed up with MRI, the sensitivity for detecting disease relapse was 90.5%.

CONCLUSION

Considering the accumulation of radiation dose in AIP patients and the insufficient sensitivity in detecting disease relapse with CT, safer and more sensitive imaging follow-up strategies should be explored.

KEY POINTS

Question CT, as the primary imaging modality for autoimmune pancreatitis (AIP) follow-up, raises concerns regarding radiation exposure and lacks reported diagnostic performance in detecting AIP relapse. Findings CT in AIP follow-up causes significant cumulative radiation exposure and exhibits insufficient sensitivity in relapse detection. Clinical relevance Type 1 AIP necessitates long-term imaging follow-up, yet current guidelines lack consensus regarding the prioritization of CT or MRI for such follow-up. CT is widely used but has radiation concerns and limited sensitivity, calling for safer, efficient strategies.

Rate of Decrease in Serum Autotaxin Can Predict Relapse of Type 1 Autoimmune Pancreatitis After Initial Steroid Therapy

OBJECTIVES

There are numerous studies on predicting relapse of autoimmune pancreatitis (AIP). Serum autotaxin (ATX) was recently found to associate with AIP relapse. This study examined the changes in serum IgG4 and ATX levels for predicting relapse in AIP patients.

MATERIALS AND METHODS

Patients with AIP who had received initial steroid therapy were retrospectively enrolled. Serum IgG4 and ATX levels were measured before and after treatment. The rates of decrease (Δ) in serum marker levels were calculated by dividing the difference between before and after steroid therapy by the number of days between them.

RESULTS

The 37 AIP patients analyzed included 26 nonrelapse and 11 relapse patients. The median Δ of serum IgG4 was 5.19 [interquartile range (IQR): 2.65-14.49] in the nonrelapse group and statistically comparable to the 3.07 (IQR: 1.79-4.43) in the relapse group ( P =0.12). The median Δ of serum ATX was 1.32×10 -3 (IQR: 0.23×10 -3 -2.45×10 -3 ) in the nonrelapse group and 0.58×10 -3 (IQR: -1.34×10 -3 -0.91×10 -3 ) in the relapse group, which was a significant difference ( P <0.01). Positive predictive values for relapse was 86.5% when the Δ of IgG4 and the Δ of ATX were combined.

CONCLUSIONS

The combination of IgG4 and ATX decrease rates may help predict relapse in AIP patients after steroid therapy.

A convolutional neural network-based system for identifying neuroendocrine neoplasms and multiple types of lesions in the pancreas using EUS (with videos)

BACKGROUND AND AIMS

EUS is sensitive in detecting pancreatic neuroendocrine neoplasm (pNEN). However, the endoscopic diagnosis of pNEN is operator-dependent and time-consuming because pNEN mimics normal pancreas and other pancreatic lesions. We intended to develop a convolutional neural network (CNN)-based system, named iEUS, for identifying pNEN and multiple types of pancreatic lesions using EUS.

METHODS

Retrospective data of 12,200 EUS images obtained from pNEN and non-pNEN pancreatic lesions, including pancreatic ductal adenocarcinoma (PDAC), autoimmune pancreatitis (AIP), and pancreatic cystic neoplasm (PCN), were used to develop iEUS, which was composed of a 2-category (pNEN or non-pNEN pancreatic lesions) classification model (CNN1) and a 4-category (pNEN, PDAC, AIP, or PCN) classification model (CNN2). Videos from consecutive patients were prospectively collected for a human-iEUS contest to evaluate the performance of iEUS.

RESULTS

Five hundred seventy-three patients were enrolled in this study. In the human-iEUS contest containing 203 videos, CNN1 and CNN2 showed an accuracy of 84.2% and 88.2% for diagnosing pNEN, respectively, which were significantly higher than that of novices (75.4%) and comparable with intermediate endosonographers (85.5%) and experts (85.5%). In addition, CNN2 showed an accuracy of 86.2%, 97.0%, and 97.0% for diagnosing PDAC, AIP, and PCN, respectively. With the assistance of iEUS, the sensitivity of endosonographers at all 3 levels in diagnosing pNEN has significantly improved (64.6% vs 44.8%, 87.5% vs 71.9%, and 74.0% vs 57.6%, respectively).

CONCLUSIONS

The iEUS precisely diagnosed pNEN and other confusing pancreatic lesions and thus can assist endosonographers in achieving more accessible and accurate endoscopic diagnoses with EUS. (Clinical trial registration number: ChiCTR2100049697.).

Endoscopic diagnosis of immunoglobulin G4-related sclerosing cholangitis

Immunoglobulin G4 (IgG4)-related sclerosing cholangitis (IgG4-SC) is a distinct form of sclerosing cholangitis frequently associated with autoimmune pancreatitis and is recognized as a biliary manifestation of IgG4-related disease. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) are key diagnostic modalities for IgG4-SC. Cholangiocarcinoma and primary sclerosing cholangitis (PSC) are significant mimickers of IgG4-SC. ERCP is employed to evaluate narrowing of the bile duct, with cholangiograms of IgG4-SC classified into four types. This cholangiographic classification is crucial for differential diagnosis. Characteristic cholangiographic findings of IgG4-SC include diffuse or segmental strictures of the intrahepatic or extrahepatic bile ducts and intrahepatic strictures associated with autoimmune pancreatitis. ERCP is particularly useful for differentiating IgG4-SC from PSC because their cholangiographic features differ. EUS and intraductal ultrasonography (IDUS) are used to assess thickening of the bile duct wall. Characteristic IDUS findings in IgG4-SC include circular and symmetrical wall thickening, smooth outer and inner margins, and homogeneous internal echoes at stricture sites. Additionally, bile duct wall thickening at nonstricture sites is a typical IDUS feature of IgG4-SC. Bile duct biopsy is used to evaluate pathological findings, although its diagnostic yield for IgG4-SC is limited; its primary role is to exclude malignant biliary strictures. Duodenal papilla biopsy serves as a supplementary diagnostic tool for IgG4-SC. EUS and tissue acquisition also aid in diagnosing autoimmune pancreatitis as part of other organ involvement. Thus, endoscopic techniques play critical roles in the diagnosis of IgG4-SC.

Differences in the Fecal Metabolome of Autoimmune Pancreatitis Patients

BACKGROUND

Chronic pancreatitis is a risk factor for pancreatic cancer. Autoimmune pancreatitis is a unique form of chronic pancreatitis that is primarily characterized by its immune mediate etiology, clinically resembling pancreatic cancer, yet uniquely responsive to steroid treatment.

OBJECTIVE

Early and accurate diagnosis of autoimmune pancreatitis is vital for effective treatment and patient prognosis, for which new diagnostic tools are urgently required. Gut microbiota dysbiosis has been identified to correlate with the development of pancreatic diseases, which provides new opportunities for the discovery of disease biomarkers.

METHODS

We utilized a mass spectrometric global metabolomics investigation of patient autoimmune pancreatitis and chronic pancreatitis fecal samples, investigating microbiome, dietary and human metabolism.

RESULTS

We discovered a series of newly identified metabolic signatures between both patient groups including enterolactone, 4-guanidinobutanoic acid, and methylthioadenosine sulfoxide. Additionally, the analysis revealed significant differences in several metabolic pathways such as fatty acids, alkaloids, amino acids and peptides.

CONCLUSION

Our observations provide novel insights into important metabolic human pathways and microbiome-derived metabolites to distinguish autoimmune pancreatitis from chronic pancreatitis. These findings reveal systemic metabolic responses and the identified metabolites may be developed into potential biomarkers for future diagnosis to distinguish between autoimmune pancreatitis and chronic pancreatitis.

Clinical features and long-term prognosis of type 1 autoimmune pancreatitis based on the location of bile duct lesions

BACKGROUND/PURPOSE

Type 1 autoimmune pancreatitis (AIP) frequently involves biliary lesions and poses diagnostic and therapeutic challenges. We aimed to evaluate the clinical features and long-term prognosis of type 1 AIP with a focus on the locations of bile duct lesions.

METHODS

In this retrospective study, 159 patients with type 1 AIP were included. Patients were classified on the basis of the location of bile duct strictures, and clinical outcomes, including relapse rates and steroid dependency, were analyzed.

RESULTS

Eighty-nine (56%) patients had bile duct involvement. Forty-nine patients (30.8%) experienced relapse, with a significantly higher cumulative relapse rate in cases of stricture or wall thickening upstream of the intrapancreatic bile duct (3 years: 24% vs. 37.1%, p < .001). These patients also had a significantly higher rate of two or more relapses than did the patients without stricture or wall thickening (5.1% vs. 19.5%, p = .01). Two patients with stricture and dilation up to the intrahepatic bile ducts became steroid-dependent and were treated with azathioprine.

CONCLUSIONS

Patients with type 1 AIP with biliary lesions involving upstream strictures or wall thickening, especially those with stricture and dilation extending into the intrahepatic bile ducts, are at high risk of relapse and may become steroid dependent.

Pediatric Autoimmune Pancreatitis: Clinical Findings and Outcomes in Sweden

Introduction

Pediatric autoimmune pancreatitis (AIP) is a rare form of pancreatitis in children with poorly understood pathophysiology. It is a recognized risk factor for chronic pancreatitis in approximately 4% of pediatric cases. This study aims to describe the demographics, clinical characteristics, and outcomes of a large Swedish cohort of pediatric AIP patients.

Patients and Methods

A retrospective analysis of medical records was conducted for patients diagnosed with pediatric AIP between January 2006 and December 2022.

Results

Thirty‐seven patients were included (20 males, 17 females; mean age 13.5 ± 2.8 years). None had a family history of pancreatic diseases. Most patients (62.2%) presented with acute pancreatitis, followed by weight loss (45.9%), abdominal pain (43.2%), jaundice (21.6%), and fatigue (16.2%). Acute pancreatitis was mild in all cases according to the Atlanta criteria. Multi‐organ involvement was observed in 81.1% of patients, and inflammatory bowel disease (IBD) was present in 62.2%. A total of 75.7% of patients received treatment, mainly glucocorticoids, while 24.3% had spontaneous regression. Complete clinical and radiological remission was achieved in 83.8% of treated patients. Pancreatic exocrine insufficiency was present in 43.2% of patients at diagnosis, reducing to 24.3% at the final follow‐up. No patients developed diabetes mellitus, except for one who underwent total pancreatectomy due to suspected pancreatic tumor.

Conclusions

Pediatric AIP is a rare condition often associated with multi‐organ involvement particularly IBD. Most patients respond well to glucocorticoid treatment and achieve remission. Managing IBD may improve the outcomes for both conditions.

Management of acute pancreatitis in the "no man's land"

Acute pancreatitis (AP) is an inflammatory disease that can represent a challenge for clinicians, in fact, the early determination of its severity in the first 72 h is crucial for prognosis, recognizing the etiology and carrying out risk stratification to determine a more specific therapy. No accurate early prognostic scores for disease severity have been published, so the severity of AP often cannot be properly defined in the first few hours of the disease. This initial phase represents a "no man's land", in which there is no certainty in the stratification of the damage, prognosis is difficult to establish, therapy must be started promptly, although there is still no effective medical therapy against pancreatic enzymatic activation. Therefore, it is very difficult at this stage to make the correct decisions to achieve the best outcome for the patient with AP. Literature search was carried out using the PubMed database by entering early management of acute pancreatitis [title] or therapy of acute pancreatitis [title] and selecting the most relevant articles for the diagnosis and therapy of acute pancreatitis in clinical practice. This document provides suggestions on managing the key clinical decisions for patients suffering from AP before disease severity is defined, to achieve the best outcomes for patients with AP.

Somatosensory profiling to differentiate distinct painful diseases of the pancreas-a quantitative sensory testing case-control study

ABSTRACT

Mechanisms of pancreatic pain are insufficiently understood, and quantitative sensory testing (QST) may help to identify the underlying mechanisms. Accordingly, this study assessed comprehensive somatosensory profiles encompassing nociceptive and nonnociceptive parameters in 70 patients with distinct pancreatic diseases, namely acute (n = 23), chronic (n = 20), or autoimmune pancreatitis (n = 10) and pancreatic cancer (n = 17) and compared it with 30 healthy control subjects by standardized QST (protocol of the German research network on neuropathic pain). Patients with pancreatic diseases presented significant somatosensory deficits in all thermal and tactile detection and pain thresholds in the pancreatic viscerotome (Th10), when compared with a remote control area (dermatome C5) or reference data of matched healthy controls (P < 0.05-P < 0.0001). Unaltered vibration detection emphasizes the strictly regional character of losses. Loss of sensitivity paralleled the occurrence of paradoxical heat sensation (Th10 vs C5; P < 0.05), an indicator of thermal integration deficit. Punctate hyperalgesia or pain to light touch, the hallmark signs of spinal central sensitization were mostly absent and pain summation remained unchanged (P > 0.05). Stratification of patients revealed that somatosensory deficits were significantly more pronounced in acute compared with chronic pancreatitis (eg, cold and warm detection thresholds: -2.19 ± 1.42 vs -1.10 ± 1.23 and -1.30 ± 1.68 vs -0.11 ± 1.80 z-values; P < 0.05 each). Notably, blunt pressure hyperalgesia, the only somatosensory parameter exhibiting significant gain compared with the patients' remote C5 segment, was a frequent finding only in acute, but not in chronic pancreatitis. The somatosensory phenotype of patients with distinct pancreatic disorders was characterized by a wide array of sensory losses being most severe in acute pancreatitis.

Pancreatitis-related benign biliary strictures: a review of imaging findings and evolving endoscopic management

Biliary strictures can be secondary to a gamut of etiologies, most of which are malignant and the remaining related to a host of benign causes, including pancreatitis. Pancreatitis related benign biliary strictures (BBS) primarily involve the distal common bile duct (CBD) and can be seen in acute and chronic pancreatitis as well as their other forms, including necrotizing, groove, and autoimmune pancreatitis. Patients with pancreatitis related BBS present along a wide clinical spectrum that spans from an asymptomatic state to biliary obstruction, which not uncommonly facilitates additional workup for malignancy and endoscopic evaluation and treatment. Furthermore, the location and appearance of these strictures lends itself to various imitating benign and malignant etiologies. In this article, we will discuss the pathophysiology and clinicoradiologic features of pancreatitis related BBS while providing a review of an approach to their management focusing on endoscopic techniques.

Immune checkpoint inhibitors-induced pancreatitis: a systematic review and real-world pharmacovigilance analysis

Purpose

Immune checkpoint inhibitors-induced pancreatitis (ICIs-P) is an uncommon immune-related adverse event. The available evidence consists mostly of case reports, case series, and narrative reviews. This research focuses on the clinical characteristics and management options for ICIs-P to provide a practice-based global perspective on this disease.

Methods

Five electronic databases were systematically reviewed to identify the relevant studies. Furthermore, we performed a disproportionality analysis utilizing OpenVigil 2.1 to interrogate the United States Food and Drug Administration's Adverse Event Reporting System (FAERS) database.

Results

A total of 61 patients from 58 studies were included in this study. Most patients with ICIs-P were males (60.7%). Most patients received anti-PD-1/PD-L1 monotherapy (78.7%) or anti-PD-1/PD-L1 monotherapy in conjunction with CTLA-4 blockade (19.7%). The median time from the initiation of immune checkpoint inhibitors treatment to pancreatitis was 108 days (range 52-278). Most cases were severe or life-threatening (G3-G4; 64.0%). Corticosteroids were administered to 73.8% of the patients during the treatment of pancreatitis. Regarding treatment outcomes, ICIs-P was reversible in most cases (83.6%), despite the 8.2% relapse and 8.2% deaths. We identified 606 reports of pancreatitis associated with ICIs in the FAERS database, with the greatest proportion of males (50.7%), 62.0% of PD-1 inhibitors, and 22.1% of all reports of death or life-threatening outcomes. Signals indicating pancreatitis were observed across all ICIs, with particular emphasis on Cemiplimab, Pembrolizumab and Nivolumab.

Conclusion

By using a pharmacovigilance database, we discovered an elevated risk of pancreatitis following ICIs therapy, especially with PD-1 inhibitors. Meanwhile, risk factors for ICIs-P remain poorly understood, and diagnosis is challenging. Which may manifest as asymptomatic elevated pancreatic enzyme levels or clinical pancreatitis. Patients with pancreatitis symptoms should have their lipase and amylase levels and radiology evaluated. Diagnosis should be made by excluding other causes. Steroids are the cornerstone of ICIs-P treatment and slow dose reduction is recommended to reduce recurrence.

Unraveling the Microenvironment and the Pathogenic Axis of HIF-1α-Visfatin-Fibrosis in Autoimmune Pancreatitis Using a Single-Cell Atlas

Autoimmune pancreatitis (AIP) is identified as a severe chronic immune-related disorder in pancreas, including two subtypes. In this study, pancreatic lesions in patients diagnosed as either type 1 AIP or type 2 AIP are examined, and these patients' peripheral blood at single-cell level. Furthermore, flow cytometry, immunofluorescence, and functional assays are performed to verify the identified cell subtypes. In type 1 AIP, there is a notable increase in the amount of B cells and plasma cells, and IgG4+ plasma cells are key pathogenic cells of AIP. The differentiation path of naïve-stage B cells into IgG4+ produced plasma cells is observed, and an increased amount of T helper cells and T follicular helper (Tfh) cells. This study also reveals that HIF-1α, an activated transcriptional factor, can directly bind to promoter site of NAMPT, promoting higher levels of visfatin production in HIF1A+ classical monocytes. Pancreatic stellate cells can be activated by extracellular visfatin and promote the development of fibrotic response in pancreatic lesions across both AIP subtypes. The current findings shed light on the exploration of dynamic alterations in peripheral blood cells and cell subgroups in pancreatic lesions of AIP, while elucidating a pathogenic cell subset and potential fibrosis mechanism of AIP.

What Is the Latest in Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a steroid-responsive fibroinflammatory disorder with 2 clinically distinct subtypes known as type 1 autoimmune and type 2 autoimmune pancreatitis. Type 1 AIP is considered the pancreatic manifestation of immunoglobulin G4-related disease, a systemic disease often presenting with other organ involvement. Advances in understanding the unique clinical presentation, imaging findings, histopathology, and clinical course of this relatively uncommon disease have led to international consensus regarding diagnosis and treatment. While corticosteroids remain the mainstay of treatment, several emerging novel therapies have been explored primarily in the context or relapsing and refractory cases.

Endoscopic ultrasound-guided fine-needle biopsy needle can facilitate histological diagnosis of type 1 autoimmune pancreatitis

BACKGROUND

The choice between 22-gauge endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) and EUS-guided fine-needle aspiration (EUS-FNA) for histological diagnosis of type 1 autoimmune pancreatitis (AIP) is unclear. We retrospectively examined the detection rate of histological findings for AIP using EUS-FNA/FNB.

METHODS

Patients diagnosed with type 1 AIP using EUS-FNB (Franseen needle) or EUS-FNA (conventional needle) with 22-gauge needles at our hospital between 2012 and 2023 were included in this study. AIP was diagnosed according to International Consensus Diagnostic Criteria (ICDC). The detection rates of level 1 findings, which included storiform fibrosis and/or obliterative phlebitis, and level 2 histological findings were evaluated according to the ICDC.

RESULTS

The EUS-FNB and EUS-FNA groups included 25 and 24 patients, respectively. No significant differences in patient background were noted between the two groups. The detection rates of prominent filtration of lymphocytes and plasma cells along with fibrosis were 56.0% in the EUS-FNB group and 12.5% in the EUS-FNA group (p = .001). The detection rates of more than 10 IgG4-positive plasma cells per high-power microscopic field were 68.0% and 29.2% in the EUS-FNB and EUS-FNA groups, respectively (p = .007). The histological findings for levels 1 and 2 were significantly higher in the EUS-FNB group (56.0% vs. 12.5%; p = .001). Mild pancreatitis was observed in the EUS-FNB group; however, no other serious adverse events occurred.

CONCLUSION

The 22-gauge EUS-FNB yielded a higher rate of histological findings than 22-gauge EUS-FNA, suggesting that 22-gauge EUS-FNB is suitable and safe for the histological diagnosis of type 1 AIP.

Clinical and Investigative Approach to Recurrent Acute Pancreatitis

Recurrent acute pancreatitis (RAP) is a complex syndrome that presents variably, with many cases remaining idiopathic after thorough diagnostics. For evaluating structural etiologies, endoscopic ultrasound and MR cholangiopancreatography are preferred over endoscopic retrograde cholangiopancreatography (ERCP) given their more favorable risk profile and sensitivity. The diagnostic work-up remains paramount since treatment should focus on addressing underlying causes such as early cholecystectomy for gallstone pancreatitis. As more etiologic factors are uncovered, such as genetic susceptibility, causality becomes more nuanced. Earlier enthusiasm for endoscopic sphincterotomy as a treatment for idiopathic RAP has been tempered by less favorable studies in recent years.

Multisystem diseases in the abdomen and pelvis: imaging manifestations and diagnostic roles of cross-sectional imaging

Systemic diseases, such as IgG4-related disease, sarcoidosis, and amyloidosis, usually involve multiple systems or organs simultaneously or sequentially. The gastrointestinal tract, hepatobiliary system, and genitourinary tract are commonly involved in many multisystem diseases and can also be the first sites with disease involvement. Cross-sectional imaging, such as CT and MR, plays an important role in the diagnosis and management of multisystem diseases by aiding in the evaluation of multiorgan involvement. Here, common imaging features of frequently affected organs are reviewed in multisystem diseases that we often encounter in the abdomen and pelvis, and the diagnostic roles of cross-sectional imaging for these diseases are also discussed.

Impact of EUS-guided fine-needle biopsy sampling on International Consensus Diagnostic Criteria for diagnosing autoimmune pancreatitis: a prospective multicenter study

BACKGROUND AND AIMS

Histologic diagnosis of autoimmune pancreatitis (AIP) may be difficult to obtain preoperatively. Based on promising results using new-generation "end-cutting" needles, we aimed to assess the utility of EUS-guided fine-needle biopsy sampling (EUS-FNB) in enhancing diagnostic levels of International Consensus Diagnostic Criteria (ICDC) in probable patients with AIP and in defining the specific AIP subtype.

METHODS

Adult patients with suspected AIP were prospectively and competitively enrolled at 4 centers. Definitive AIP diagnosis, according to the ICDC, or patients recently treated with steroids were excluded. A 22-gauge end-cutting needle was used in all cases. The primary outcome was the rate of enhanced ICDC levels. Secondary outcomes were rates of levels 1 or 2, EUS-FNB diagnostic accuracy, rate of malignancy, and safety.

RESULTS

Fifty-two patients with focal (50) and diffuse (2) suspected AIP were enrolled (75% men; mean age, 57.9 ± 17.3 years). Final diagnoses were AIP, chronic pancreatitis, and malignancy in 39 (75%), 6 (11.5%), and 7 (13.5%) patients, respectively. EUS-FNB improved the diagnostic level of AIP in 92.3% (74.3% definitive and 17.9% probable). The rate of histology level 1 compatible with a diagnosis of type 1 and type 2 AIP was 73.1% and 50%, respectively. The rate of histology level 2 was 23.1% and 41.7% in type 1 and type 2, respectively. The overall diagnostic accuracy of EUS-FNB was 94.2% (95% CI, 84.1-98.8). Two mild cases of pancreatitis (3.8%) occurred after EUS-FNB.

CONCLUSIONS

EUS-FNB using end-cutting needles enhanced the ICDC in >90% of patients, ruling out malignancy in focal presentations and defining the specific subtype of AIP. (Clinical trial registration number: NCT04397731.).

Groove Pancreatitis in Focus: Tumor-Mimicking Phenotype, Diagnosis, and Management Insights

Background/Objectives: Groove pancreatitis (GP) is an uncommon pancreatic condition implying a challenging differential diagnosis. This study aims to comprehensively evaluate the main risk factors, clinical presentation, imaging and endoscopic characteristics of patients with GP, providing insights into an effective diagnostic approach and therapeutic strategies. Methods: A retrospective analysis was conducted on patients diagnosed with GP, with demographic and clinical data collected. The diagnostic route was followed by an upper endoscopy and was finally confirmed by cross-sectional imaging. In patients with high malignancy suspicion or with an uncertain diagnosis, a pancreatic endoscopic ultrasound (EUS) was further performed. According to imaging features, we divided patients into two categories: with and without tumor-like appearance. Results: Altogether, 23 patients were included, 11 in the tumor-like category, and 12 in the non-tumor-like group; 95.6% were men, 78.2% alcohol consumers, and 73.9% smokers. In both groups, the main symptom was abdominal pain, followed by nausea and vomiting. The most frequent finding at upper endoscopy was edematous duodenal mucosa (16 patients, 80%), followed by mucosal hyperemia (8 patients, 40%). The main finding at cross-sectional imaging was duodenal wall thickening (14 patients, 60.9%), followed by pancreatic head enlargement and duodenal wall cysts (both seen in 12 patients, 52.2%). The EUS predominantly showed duodenal wall thickening (13 patients, 68.4%), and intramural and paraduodenal cysts (10 patients, 52.6%). Conclusions: GP predominantly affects men with a history of chronic alcohol and tobacco use. Its primary diagnostic challenge lies in distinguishing it from pancreatic carcinoma, with an accurate diagnostic workup being crucial in clinical practice.

Treatment Strategies for Chronic Pancreatitis (CP)

Chronic pancreatitis (CP) and autoimmune pancreatitis (AIP) are diseases with overlapping features, both requiring complex management strategies. CP is characterized by pancreatic exocrine insufficiency (PEI) and pain, with treatment focused on symptom relief through pancreatic enzyme replacement therapy (PERT), pain control, and lifestyle and nutritional changes. However, the standard therapy does not address the underlying inflammation or fibrosis, which drives disease progression. AIP, on the other hand, presents with obstructive jaundice and fibrosis and is classified into two subtypes: Type 1 (AIP-1), linked to IgG4-related disease, and Type 2 (AIP-2), associated with inflammatory bowel disease. Treatment for AIP typically involves oral steroids. Immunomodulators and rituximab are used for recurrent or refractory cases. Novel therapies targeting the inflammation and fibrotic components of CP are being explored. A multidisciplinary approach is essential to optimize care and improve patients' outcomes.

Autoimmune pancreatitis, pancreatic and extrapancreatic cancer (AIPPEAR): a multicentre, retrospective study protocol

INTRODUCTION

Autoimmune pancreatitis (AIP) mainly manifests in two distinct forms with different clinical, serological and prognostic characteristics. Previous studies indicated a higher risk of malignancy in AIP patients compared with the general population. However, a direct comparison of cancer incidence in AIP patients with controls from the general population has not been conducted yet.

METHODS AND ANALYSIS

This is an international, multicentre, retrospective study on patients diagnosed with AIP after 2005. Retrospective data regarding demography, AIP characteristics and cancer incidence will be extracted from the medical files of AIP patients. The primary outcome is the standardised incidence ratio of any first invasive cancer after AIP diagnosis compared with the general population. The expected number of cancers in the general population will be determined using the 'Cancer Incidence in Five Continents Volume XI' registry. Secondary outcomes are the prevalence of all cancer diagnoses within 12 months prior to AIP diagnosis and AIP features associated with a cancer diagnosis.

ETHICS AND DISSEMINATION

This study was approved by the ethics committees of the autoimmune pancreatitis, pancreatic and extrapancreatic cancer (AIPPEAR) core group centres (Halle (Saale), Germany; Aalborg, Denmark; Tartu, Estonia; Munich, Germany; Göttingen, Germany; Maribor, Slovenia, with the following reference numbers: 2023-204, 2023-0 29 953, 382 /T-3, 24-0768, 9/7/23, UKC-MB-KME 59/23, respectively). Where required, the study protocol will be reviewed and approved by the ethics committees of participating centres in compliance with local regulations. Data will be stored in an electronic case report form within REDCap. In this context, the AIPPEAR core group will share joint responsibility for the data. All results from this study will be submitted to international, peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT06328101.

Autoimmune Pancreatitis Mimicking a Pancreatic Neuroendocrine Tumor: A Case Report with a Literature Review

Autoimmune pancreatitis (AIP) is a rare chronic pancreatitis subtype that often mimics pancreatic cancer due to the overlapping clinical and radiological features, posing significant diagnostic challenges. Similarly, distinguishing AIP from pancreatic neuroendocrine neoplasms (PanNENs), which present with nonspecific symptoms, adds complexity to clinical evaluations. We present the case of a 46-year-old male with recurrent acute idiopathic pancreatitis. Abdominal computed tomography (CT) revealed a 25 mm hypodense mass in the pancreatic tail with mild arterial contrast enhancement. Magnetic resonance imaging (MRI) showed the mass to be hypointense on T2-weighted sequences, with no diffusion restriction and an enhancement pattern akin to normal pancreatic tissue. The endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) was inconclusive. Gallium-68 DOTATATE positron emission tomography-CT (Ga-68 DOTATATE PET-CT) showed an increased tracer uptake, leading to a distal pancreatectomy with a splenectomy. Histopathology demonstrated chronic sclerotic pancreatitis with inflammatory infiltrates. Elevated serum IgG4 levels confirmed the diagnosis of type 1 AIP Differentiating AIP from pancreatic malignancies, including PanNENs, is both critical and complex. This case highlights a misdiagnosis of PanNENs in a patient with focal AIP, where neuroendocrine hyperplasia and islet cell clusters within fibrotic areas mimicked PanNENs, even on Ga-68 PET-CT. The findings emphasize the potential for false positives with Ga-68 DOTATATE PET-CT and the importance of integrating clinical, radiological, and histological data for an accurate diagnosis.

Serum IgG4-negative and IgG4-positive type 1 autoimmune pancreatitis present with different clinicopathological features: An analysis of a nationwide survey in Japan

BACKGROUND/OBJECTIVE

Elevated serum IgG4 (sIgG4) is a useful diagnostic marker of type 1 autoimmune pancreatitis (AIP). This study aimed to clarify the clinicopathological characteristics of the type 1 AIP patients without elevated sIgG4 levels.

METHODS

We analyzed the clinical data of patients registered in a nationwide epidemiological survey in Japan. AIP was diagnosed according to the International Consensus Diagnostic Criteria. Patients with sIgG4 levels ≥135 mg/dl at the diagnosis were classified as sIgG4-positive AIP, and those with sIgG4 levels <135 mg/dl were as sIgG4-negative AIP.

RESULTS

A total of 1285 patients with AIP were enrolled in this study; 1128 (87.8 %) had sIgG4-positive AIP and 157 (12.2 %) had sIgG4-negative AIP. Compared to patients with sIgG4-positive AIP, those with sIgG4-negative AIP more frequently experienced inflammatory bowel diseases (3.8 % vs. 0.4 %), and less frequently developed extrapancreatic lesions (53.5 % vs. 72.3 %), including sclerosing cholangitis (30.6 % vs. 40.7 %) and sialadenitis/dacryoadenitis (5.1 % vs. 24.7 %). Histopathological examinations were performed more frequently in patients with sIgG4-negative AIP. The criterion of abundant IgG4-positive plasma cells was less frequently fulfilled by patients with sIgG4-negative AIP (28.0 % vs. 43.1 %). A Kaplan-Meier analysis showed that relapse occurred less frequently in patients with sIgG4-negative AIP (P = 0.006). Results were similar even if the patients with AIP-not otherwise specified (n = 45) were excluded.

CONCLUSIONS

Patients with sIgG4-negative type 1 AIP and those with sIgG4-positive type 1 AIP present with different clinicopathological features which suggests heterogeneity of patients with type 1 AIP. Low serum IgG4 levels could indicate low disease activity in type 1 AIP.

Chronic and Idiopathic Pancreatitis-A Personalized Treatment Approach

Chronic pancreatitis is a fibroinflammatory disease of the pancreas with heterogeneous clinical features and a significant socioeconomic burden. Assessing its aetiology and early diagnosis of associated complications remain challenging. Personalized therapy necessitates precise knowledge of the genetic, biological, and clinical differences within a patient population. In this context, the identification of the underlying aetiology represents an essential cornerstone. This review elucidates current standards for identifying underlying aetiologies and the diagnostic work-up for idiopathic cases. It provides an overview of general therapeutic approaches and highlights individual treatment options. Additionally, the follow-up management of pancreatitis-associated complications, namely exocrine pancreatic insufficiency, post-pancreatitis diabetes mellitus, pain management, pancreatic fluid collections, and pancreatic cancer risk, is summarized.

Update on Autoimmune Pancreatitis and IgG4-Related Disease

Autoimmune pancreatitis is an increasingly recognized inflammatory type of subacute pancreatitis; two subtypes of autoimmune pancreatitis have been identified so far: the "lymphoplasmacytic" type 1 variant and the "neutrophilic" type 2 variant. Type 1 autoimmune pancreatitis represents the most common manifestation of IgG4-related disease, a fibro-inflammatory disorder characterized by elevated IgG4 levels in the serum and affected tissues. Type 2 autoimmune pancreatitis is a pancreas-specific disorder that frequently occurs in the context of inflammatory bowel diseases. Due to the complexity of both diseases, a comprehensive work up with imaging, laboratory, and histological studies is required to achieve a diagnosis and rule out malignancies. Glucocorticoids represent the cornerstone of the treatment, often supported by other immunosuppressive drugs in case of steroid intolerance or aggressive disease. Maintenance treatment is often employed in type 1 autoimmune pancreatitis because of the higher relapse rate compared with type 2 autoimmune pancreatitis. In this review, we summarize the key concept of autoimmune pancreatitis, delve into the differential diagnosis between the two subtypes, and cover the recent relevant research findings and pressing unmet needs.

Acute Pancreatitis: An Unusual Side Effect of Adalimumab in Crohn's Disease Patient

Background

Drug-induced acute pancreatitis is a rare condition occurs at an incidence rate of 0.1-1.4% and represents a diagnostic challenge. TNFα inhibitors specially adalimumab is very rarely reported in the literature, primarily through case reports, as a potential cause of acute pancreatitis.

Case presentation

Our case report presents a case of a 23-year-old patient followed for Crohn disease in whom a diagnosis of acute pancreatitis induced by adalimumab was made. This diagnosis was confirmed after the elimination of other possible etiologies, and notably by the recurrence of pancreatitis after Adalimumab rechallenge. The occurrence of acute pancreatitis induced by TNFα inhibitors exposes to the risk of pancreatitis with other drugs in this class, hence the need to switch to another therapeutic class, which was Ustekinumab in our case.

Conclusion

Acute pancreatitis is an unusual complication of treatment with Adalimumab. Through our experience, based on solid scientific data, we want to draw the attention of clinicians to the reality of this complication. It should be considered in any patient on TNFα inhibitors who presents with acute pancreatitis without an obvious cause.

Immunoglobulin G4-related Autoimmune Pancreatitis and Hypopituitarism Following Immune Checkpoint Inhibitor Therapy

A 70-year-old man underwent nephrectomy for renal cell carcinoma followed by 3 cycles of pembrolizumab as adjuvant chemotherapy. Three months later, he complained of appetite loss. He was diagnosed with secondary adrenal insufficiency and pancreatic tumor. Amylase and immunoglobulin G (IgG) 4 levels were normal. The differential diagnosis poses challenges in distinguishing pancreatic cancer, renal cell carcinoma metastasis, and autoimmune pancreatitis, necessitating tumor resection surgery. A histological examination revealed IgG4-related sclerosing pancreatitis. Postoperatively, there was no recurrence of pancreatitis. It is essential to consider the potential development of IgG4-related diseases after the administration of immune checkpoint inhibitors.

Neutrophil extracellular DNA traps activate the TLR9 signaling pathway of pancreatic ductal epithelial cells in patients with type 2 autoimmune pancreatitis

The presence of neutrophil infiltration around the pancreatic ducts has been found to be associated with type 2 autoimmune pancreatitis (AIP). However, the functional role and clinical significance of neutrophil migration in the progression of pancreatitis is not fully understood. Here, we found that neutrophil extracellular traps (NETs) are abundant around the pancreatic duct in patients with type 2 AIP. We also observed an increased expression of toll-like receptor 9 (TLR9) in pancreatic ductal epithelial cells (HPDEC) in type 2 AIP patients compared to other pancreatic diseases. TLR9 acts as the DNA component of NETs (NET-DNA) receptor in HPDEC, which senses extracellular DNA and subsequently activates the NF-κB pathway to promote neutrophil recruitment and induce NET formation. In addition, our results indicated that the hydroxychloroquine (HCQ), acting as a TLR9 antagonist, could effectively inhibit the activation of inflammatory pathways, reduce neutrophil migration and block the positive feedback loop. The intervention positions HCQ acts as a potential target drug for the clinical treatment of type 2 AIP.

Autoimmune Pancreatitis in Children: A Case Report

Introduction

Autoimmune pancreatitis (AIP) is a rare and distinct condition in children compared to adults. Despite being based on adult diagnostic criteria, several differences have been reported, making pediatric AIP a challenging diagnosis.

Case Presentation

A 14-year-old adolescent presented to the emergency department with abdominal pain, vomiting, and jaundice. A combination of biological and radiological assessments led to the diagnosis of AIP. The patient experienced a swift and complete recovery without intensive treatment.

Conclusion

AIP in children is an intriguing diagnosis and should be considered when a child presents with abdominal pain, vomiting, and jaundice. The natural history and pathophysiology of the disease are still uncertain. Specific markers for the disease need to be established. Studies on larger sample sizes are necessary to address these questions and improve AIP diagnosis and management.

Mass-forming type 2 autoimmune pancreatitis with upstream dilatation of the main pancreatic duct dilatation: a case report

BACKGROUND

Type 2 autoimmune pancreatitis is characterized by multiple or segmental strictures of the main pancreatic duct without upstream dilatation. We encountered a case of mass-forming type 2 autoimmune pancreatitis with upstream main pancreatic duct dilatation that was difficult to diagnose preoperatively using endoscopic ultrasound sonography-guided fine-needle aspiration cytology.

CASE PRESENTATION

A 58-year-old Japanese man presented with recurrent acute pancreatitis secondary to a 10-mm pancreatic head tumor. The tumor compressed the main pancreatic duct, thereby dilating the upstream main pancreatic duct. The serum immunoglobin G4 levels were within normal limits. Endoscopic ultrasound sonography-guided fine-needle aspiration cytology was performed twice. However, few degenerative atypical cells were observed, resulting in an indeterminate diagnosis. The patient underwent pancreaticoduodenectomy, and pathological findings revealed duct-centric pancreatitis with neutrophilic infiltration of the interlobular pancreatic ductal epithelium. Immunoglobin G4-positive cells were not detected. The patient was diagnosed with type 2 autoimmune pancreatitis.

CONCLUSION

Mass-forming type 2 autoimmune pancreatitis can present with main pancreatic duct strictures and upstream dilatation. Although endoscopic ultrasound sonography-guided fine-needle aspiration cytology is useful for the diagnosis of solid pancreatic masses, preoperative diagnosis of type 2 autoimmune pancreatitis remains challenging. Further studies should be conducted to determine whether "hidden" type 2 autoimmune pancreatitis may be more frequently present and to improve the accuracy of the diagnosis of type 2 autoimmune pancreatitis.

Hyperthyroidism and hypothyroidism in patients with autoimmune pancreatitis

OBJECTIVE

The objective of this study is to clarify the clinical features of thyroid dysfunction observed in patients with autoimmune pancreatitis (AIP).

METHODS

We repeatedly examined thyroid function in 74 patients with type 1 AIP (58 males, 16 females; average onset age of AIP 67 years). Clinical and serological findings in patients with thyroid dysfunction were analyzed.

RESULTS

During follow-up, clinical and subclinical hypothyroidism were observed in 3 and 17 patients, respectively. Clinical and subclinical hyperthyroidism were observed in 5 and 1 patients, respectively. One patient showed clinical hyperthyroidism followed by subclinical hypothyroidism. All patients with clinical and subclinical hypothyroidism were asymptomatic and required no medical treatment, whereas four patients with clinical hyperthyroidism were symptomatic and received treatment with thiamazole.

CONCLUSION

Frequent hypothyroidism in AIP, which was previously reported, was confirmed. Moreover, in this study, the association between hyperthyroidism and AIP was demonstrated. Hyperthyroidism in AIP may be more clinically significant than hypothyroidism because patients frequently require medical treatment.

Pancreatic volume change using three dimensional-computed tomography volumetry and its relationships with diabetes on long-term follow-up in autoimmune pancreatitis

BACKGROUND

Several studies found that early pancreatic atrophy detected by computed tomography (CT) within 6 months was associated with a high incidence of diabetes in patients with type-1 autoimmune pancreatitis (AIP) receiving steroid therapy; however, no long-term follow-up studies have been performed.

AIM

To investigate pancreatic volume (PV) changes using three dimensional (3D)-CT volumetry and their relationship with IgG4 and diabetes in patients with AIP.

METHODS

This retrospective study included 33 patients with type-1 AIP receiving steroid therapy. Patients were divided into diffuse (D-type) and mass-forming type (M-type) AIP. PV was determined by semi-automated 3D-CT volumetry, and changes between initial and follow-up values were calculated. The relationship between PV and serum IgG4 levels was analyzed by Spearman's rank correlation. The PV atrophy ratio compared with the presumed normal PV at the time of last follow-up CT and its relationship with diabetes were investigated.

RESULTS

There were 16 D-type and 17 M-type patients with long-term follow-up (mean, 95.8 months). The regression curve of mean relative PV change reduced exponentially and rapidly during the first 25 months and then more slowly in both groups. The overall cumulative pancreas re-enlargement rates at 1, 3, 5, 7 and 10 years were 6.1%, 12.2%, 29.2%, 47.5% and 55.0%, respectively. There was a moderate-to-very strong positive correlation (ρ ≥ 0.4) between PV and serum IgG4 levels in nine (9/13, 69.2%) patients. All 33 patients showed pancreatic atrophy (mean 59.3%) after long-term follow-up. Patients with D-type AIP had a significantly higher atrophy rate and higher incidence of diabetes than M-type patients (P < 0.05).

CONCLUSION

PV change initially reduced exponentially and then more slowly and is considered an important factor associated with diabetes. Serum IgG4 levels were positively correlated with PV during follow-up.

Immune checkpoint inhibitor-induced pancreatic enzyme elevation in melanoma patients: Incidence, management and therapy-A multicentre analysis

BACKGROUND

Immune checkpoint inhibitors (ICI) are considered standard-of-care in the systemic treatment of melanoma. However, management of certain ICI-associated adverse events (AE) can be challenging. Incidence, course and management of immune checkpoint inhibitor-induced pancreatic injury (ICIPI) are not well-documented and specific diagnostic and therapeutic algorithms are lacking. Current management includes serological monitoring of pancreatic enzymes, radiographic imaging and corticosteroid or further immunosuppressive treatment.

OBJECTIVES

Based on previous data regarding adjuvant ICI treatment, we suspected that elevation of pancreatic enzymes may occur more frequently than reported while the clinical relevance of-particularly asymptomatic-ICIPI is still unclear.

METHODS

A collaboration of eight Austrian and Swiss dermato-oncology centres was established to retrospectively analyse a large cohort of ICI-treated patients regarding incidence and management of ICIPI. Additionally, a questionnaire-based survey concerning ICIPI-management was conducted.

RESULTS

Among 1516 melanoma patients receiving ICI therapy, 204 patients exhibited ≥CTCAE II° lipase elevation. Of these patients, 41 (20.1%) had symptoms suggestive of pancreatitis. Immunotherapy was interrupted or discontinued due to pancreatic AE in almost half of the patients. Systemic corticosteroids were administered in 103 patients (50.5%), with higher doses reported in symptomatic cases. Six per cent of asymptomatic patients had radiographically proven pancreatitis. Maximum lipase elevation was >5xULN in all of these patients.

CONCLUSION

Routine lipase monitoring was conducted in all participating centres, although not recommended in respective guidelines. Elevation of serum lipase was observed more frequently than recently reported. Although radiographic findings indicating pancreatitis were rare in asymptomatic patients, ICI treatment was frequently paused or discontinued and systemic steroids were administered. To reduce the existing uncertainty in routine clinical practice reflected by our findings, we provide an algorithm to guide the monitoring and management of potential pancreatic adverse events. Lipase measurement should be limited to symptomatic patients and/or those with radiographic findings indicative of pancreatic injury.

Immunoglobulin G4-related autoimmune hepatitis following type 1 autoimmune pancreatitis: A case report and literature review

We herein report a case of IgG4-related autoimmune hepatitis (AIH) in a patient with a history of type 1 autoimmune pancreatitis. A 56-year-old man presented with fatigue and jaundice at our hospital. A blood biochemistry analysis revealed significant liver dysfunction, positive results for antinuclear antibodies, and high serum IgG4 levels. A histopathological examination revealed interface hepatitis marked by IgG4-positive plasma cell infiltration in the portal area, leading to liver cell depletion and necrosis. Based on the diagnosis of IgG4-related AIH, prednisolone treatment was initiated, which led to the rapid resolution of liver dysfunction and jaundice. An accurate diagnosis of IgG4-related AIH is crucial to prevent secondary manifestations.

Enhancing preoperative diagnosis of pancreatic ductal adenocarcinoma and mass-forming chronic pancreatitis: a study on normalized conventional MR imaging parameters

PURPOSE

To assess the utility of signal intensity ratio (SIR) in distinguishing between mass-forming chronic pancreatitis (MFCP) and pancreatic ductal adenocarcinoma (PDAC), thereby reducing unnecessary pancreatectomies or delayed diagnosis brought by misdiagnosis.

MATERIALS AND METHODS

This retrospective study included 170 participants (34 with MFCP and 136 with PDAC) who underwent radical pancreatic surgery and were diagnosed via specimen pathology. The study group was carefully selected with a 1:4 ratio matching for sex, age, and operation time between two entities. T1 SIR, T2 SIR, arterial phase (AP) SIR, portal venous phase (VP) SIR, delay phase (DP) SIR, DWI0-50 SIR, and DWI500-1000 SIR, were calculated by dividing the signal intensity of lesions by that of the paraspinal muscle, serving as a reference organ. Intraclass Correlation Coefficient (ICC) was estimated to evaluate the intraobserver and interobserver reliability. Wilcoxon tests were employed for univariate analysis, and receiver operating characteristic (ROC) curves were generated to determine optimal cutoff points and AUC values for selected predictors. A tenfold cross-validation method was applied to validate the robustness of the results.

RESULTS

The ICC demonstrated excellent correlation for both intraobserver and interobserver(ICCs > 0.8). T1 SIR, AP SIR, VP SIR, and DP SIR were significantly lower in the PDAC group compared to the MFCP group, and exhibited good independent predictive properties with the sensitivities of 61.8, 61.8, 70.6, and 73.5%, specificities of 66.2, 68.4, 59.6, and 55.9%, and AUCs of 0.620, 0.659, 0.670, and 0.668, respectively, hovering around 0.7. The tenfold cross-validation confirmed the reliability and robustness of our findings, with consistent AUC, sensitivity, specificity, and 95% confidence intervals over 1000 iterations.

CONCLUSION

T1 SIR, AP SIR, VP SIR, and DP SIR show promise as potential imaging biomarkers for distinguishing between MFCP and PDAC.

EUS-guided fine-needle biopsy versus fine-needle aspiration for histopathological evidence for type 1 autoimmune pancreatitis: A single-center retrospective study in China

Background and Objectives

EUS is recommended for guiding pancreatic tissue acquisition in suspected autoimmune pancreatitis (AIP) cases. However, there is a lack of comparative research on the effectiveness between EUS-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (EUS-FNB) for diagnosing AIP in China. This study aimed to evaluate the diagnostic accuracy of EUS-guided tissue acquisition (EUS-TA) specifically for type 1 AIP.

Methods

Between 2010 and 2023, individuals with AIP who received EUS-TA at Changhai Hospital were included in the study.

Results

A total of 173 patients diagnosed with AIP who underwent EUS-TA were included in the final analysis. Of these, 104 patients (60.1%) received EUS-FNA, and 69 patients (39.9%) underwent EUS-FNB. Sufficient pancreatic tissue samples (>5 cells/high-power field) were obtained in 164 of 173 patients (94.8%), with success rates of 94.2% for EUS-FNA and 95.7% for EUS-FNB (P > 0.05). EUS-FNB exhibited higher rates of reliable level 1 histopathological findings (40.9% vs. 16.3%, P < 0.001) and reliable level 2 histopathological findings (33.3% vs. 12.2%, P < 0.001) compared with EUS-FNA. Furthermore, a higher occurrence of IgG4-positive plasma cell infiltration (>10 cells/high-power field) was observed with EUS-FNB compared with EUS-FNA (74.2% vs. 27.9%, P < 0.001). The multivariate logistic analysis also revealed that EUS-FNA was less effective in obtaining reliable evidence compared with EUS-FNB, as evident in both level 2 (P = 0.002; odds ratio, 0.21; 95% confidence interval, 0.08-0.56) and level 1 (P = 0.001; odds ratio, 0.19; 95% confidence interval, 0.08-0.49) histopathological evidence.

Conclusions

EUS-FNB demonstrates higher rates of level 1 and level 2 histopathological findings, as well as more abundant IgG4-positive plasma cell infiltration, compared with EUS-FNA.

Eccrine Chromhidrosis and Bilioptysis in Type 1 Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a rare form of pancreatitis. This case report focuses on type 1 autoimmune pancreatitis (AIP-1), an immunoglobulin G4 (IgG4)-related disease. It is characterized by dense infiltration of lymphocytes and plasma cells, primarily in a periductal distribution. We report a case of a 48-year-old man diagnosed with AIP-1 who subsequently developed eccrine chromhidrosis and bilioptysis during the peak of bilirubin level. This case highlights the diagnostic process followed to identify this challenging condition and demonstrates the patient's response to the mainstay treatment. Moreover, it discusses the rare symptoms that can manifest with marked hyperbilirubinemia.

New insights into predictors of autoimmune pancreatitis relapse after steroid therapy

OBJECTIVES

While autoimmune pancreatitis (AIP) responds well to steroid therapy, the high relapse rate in type 1 AIP remains a critical problem. The present study examined predictors of relapse of type 1 AIP following steroid therapy.

MATERIALS AND METHODS

Nine factors potentially predictive of relapse were analyzed in 81 AIP patients receiving steroid therapy with follow-up ≥ 12 months. The rate of serum IgG4 decrease following steroid therapy was calculated by dividing the difference between serum IgG4 values before and at two months after the start of steroid by the IgG4 value before steroid.

RESULTS

A relapse occurred in 11 patients (13.5%) during a median of 38 months. Multivariate analysis revealed that the presence of IgG4-related retroperitoneal fibrosis (HR: 5.59; 95% CI: 1.42-22.0; p = 0.014) and the low rate of serum IgG4 decrease after steroid therapy (HR: 0.048; 95% CI: 0.005-0.46; p = 0.008) were significant, independent predictors of AIP relapse. The cut-off value based on receiver operating characteristic curve data for the rate of serum IgG4 decrease before and at two months after steroid therapy distinguishing patients with and without a relapse was 0.65. Using this cut-off value, the area under the curve, sensitivity, and specificity were found to be 0.63, 0.73, and 0.60, respectively.

CONCLUSION

The low rate of serum IgG4 decrease after the start of steroid therapy and the presence of IgG4-related retroperitoneal fibrosis were predictive of type 1 AIP relapse. Cautious, gradual tapering of steroid dosage and longer maintenance therapy are recommended for patients with these factors.

A suspected case of serum IgG4-negative type 1 autoimmune pancreatitis detected due to localized pancreatic duct narrowing: a case report

A 50-year-old woman was referred to our hospital with elevated serum amylase levels. Physical examination revealed no jaundice or abdominal tenderness. Serum IgG4 was negative. Computed tomography revealed a localized pancreatic duct narrowing in the pancreatic head, with caudal pancreatic duct dilation and an intraductal papillary mucinous neoplasm. Pancreatic enlargement was not observed. Endoscopic ultrasonography (EUS) showed a small hypoechoic mass. Although EUS-guided, fine-needle aspiration was performed, no diagnosis was established. Endoscopic retrograde pancreatography showed a localized narrowing in the main pancreatic duct of the pancreatic head. A biopsy of the narrowing was performed through the minor papilla because of difficult access from the major papilla. The specimen showed the infiltration of numerous IgG4-positive plasma cells, suggesting type 1 autoimmune pancreatitis (AIP). Six months later, magnetic resonance cholangiopancreatography revealed improvement in the narrowing without specific treatment. The patient presented with localized narrowing of the pancreatic duct and caudal duct dilation, which was distinct from pancreatic cancer. Diagnostic difficulties arose from negative serum IgG4 results, the lack of typical imaging characteristics of AIP, and failure to meet the AIP criteria according to the relevant Japanese and international guidelines. However, AIP was suspected and surgery was successfully avoided through a biopsy.

Quantitative MR imaging biomarkers for distinguishing inflammatory pancreatic mass and pancreatic cancer-a systematic review and meta-analysis

OBJECTIVES

To evaluate the diagnostic performance of quantitative magnetic resonance (MR) imaging biomarkers in distinguishing between inflammatory pancreatic masses (IPM) and pancreatic cancer (PC).

METHODS

A literature search was conducted using PubMed, Embase, the Cochrane Library, and Web of Science through August 2023. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) was used to evaluate the risk of bias and applicability of the studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated using the DerSimonian-Laird method. Univariate meta-regression analysis was used to identify the potential factors of heterogeneity.

RESULTS

Twenty-four studies were included in this meta-analysis. The two main types of IPM, mass-forming pancreatitis (MFP) and autoimmune pancreatitis (AIP), differ in their apparent diffusion coefficient (ADC) values. Compared with PC, the ADC value was higher in MFP but lower in AIP. The pooled sensitivity/specificity of ADC were 0.80/0.85 for distinguishing MFP from PC and 0.82/0.84 for distinguishing AIP from PC. The pooled sensitivity/specificity for the maximal diameter of the upstream main pancreatic duct (dMPD) was 0.86/0.74, with a cutoff of dMPD ≤ 4 mm, and 0.97/0.52, with a cutoff of dMPD ≤ 5 mm. The pooled sensitivity/specificity for perfusion fraction (f) was 0.82/0.68, and 0.82/0.77 for mass stiffness values.

CONCLUSIONS

Quantitative MR imaging biomarkers are useful in distinguishing between IPM and PC. ADC values differ between MFP and AIP, and they should be separated for consideration in future studies.

CLINICAL RELEVANCE STATEMENT

Quantitative MR parameters could serve as non-invasive imaging biomarkers for differentiating malignant pancreatic neoplasms from inflammatory masses of the pancreas, and hence help to avoid unnecessary surgery.

KEY POINTS

• Several quantitative MR imaging biomarkers performed well in differential diagnosis between inflammatory pancreatic mass and pancreatic cancer. • The ADC value could discern pancreatic cancer from mass-forming pancreatitis or autoimmune pancreatitis, if the two inflammatory mass types are not combined. • The diameter of main pancreatic duct had the highest specificity for differentiating autoimmune pancreatitis from pancreatic cancer.

Serum IgG4-Negative Focal Autoimmune Pancreatitis Type 1 That Was Difficult to Diagnose Preoperatively Even with Frequent Endoscopic Ultrasound-Guided Fine-Needle Aspiration and Fine-Needle Biopsy: A Surgical Case Report

Introduction: Focal autoimmune pancreatitis (AIP) without elevated serum IgG4 levels presents a diagnostic challenge compared to pancreatic tumors, often leading to surgical intervention. Case Presentation: We report a case of serum IgG4-negative focal AIP type 1 in a 52-year-old male. Despite repeated endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and fine-needle biopsy (FNB), preoperative diagnosis was elusive. Initially, a 30-mm hypoechoic mass in the pancreatic head was detected by ultrasonography, with dynamic computed tomography revealing well-defined borders and homogeneous delayed enhancement. Serum IgG4 levels were within the normal range (115 mg/dL). Two EUS-FNAs and one EUS-FNB failed to provide a definitive diagnosis, leading to suspicion of a solid pseudopapillary neoplasm and subsequent pancreaticoduodenectomy. Postoperative histopathology confirmed focal AIP type 1 with IgG4-positive plasma cells. After 38 months, there is no recurrence, and serum IgG4 levels remain normal. Conclusion: Diagnosis of focal AIP, particularly when serum IgG4 is negative, warrants consideration despite its difficulty. Imaging findings, such as a well-defined mass with homogeneous delayed enhancement, should prompt evaluation for characteristic features like capsule-like rim, pancreatic duct penetration, and biliary tract wall thickening.

Focal Autoimmune Pancreatitis Morphologically Mimicking Pancreatic Cancer: A Case Report and Literature Review

BACKGROUND Autoimmune pancreatitis (AIP) is identified as an outlier in the clinical practice of chronic pancreatitis caused by autoimmune system dysfunction. AIP is classified into 3 subtypes: AIP type 1 and AIP type 2, which are both sensitive to corticosteroids, and the recently introduced AIP type 3. CASE REPORT We present a case of a patient who presented with painless obstructive jaundice. Computed tomography (CT) revealed hyperdense gallbladder material, further dilatation of intrahepatic bile ducts, and distention of the bile duct (15 mm). Based on the available clinical data, which were strongly compatible with pancreatic cancer, Whipple surgery was selected as the treatment for this case. The consequent histopathological report revealed areas of pancreatic parenchyma with fibrous connective tissue development and dense inflammatory cell infiltration with lymphocytes and plasmacytes, which showcased IgG4 positivity. The clinical results suggested a diagnosis of AIP type 1, and the patient was referred to his treating physician for further treatment of AIP. Preoperative histological examination of the pancreas, along with evaluation of the radiological and serological features, could have aided in determining the diagnosis of AIP type 1 pancreatitis despite the unique abnormality of this particular case. CONCLUSIONS Given the aforementioned conditions, AIP, even as a rare clinical entity, emerges as a canonical ailment and should be considered a viable possibility in clinical practice since it can exclude the patient from an unnecessary surgery.

Acute pancreatitis associated with pembrolizumab-induced hypertriglyceridemia

INTRODUCTION

Acute pancreatitis (AP) following drug-induced hypertriglyceridemia is a rare clinical phenomenon. Immune checkpoint inhibitors have revolutionized treatment for a variety of solid organ and hematological malignancies. Pembrolizumab is a programmed cell death receptor-1 (PD-1) inhibitor that has shown promising responses in many advanced cancers. However, a constellation of immune-related adverse events has also been described. There are reports of pembrolizumab-induced hypertriglyceridemia, but AP as a result of this side effect remains an exceedingly rare clinical sequela.

CASE REPORT

We delineate a case of a patient with stage IVB non-small-cell lung cancer who developed progressive abdominal pain and nausea following administration of pembrolizumab for four months. Laboratory studies revealed increased serum lipase and triglyceride levels at 12,562 IU/L and 16,901 mg/dL, respectively. The diagnosis of AP was made based on the revised Atlanta classification criteria. After ruling out alternative causes, pembrolizumab-induced hypertriglyceridemia was considered the likely etiology of AP.

MANAGEMENT AND OUTCOME

The patient was transferred to the medical intensive care unit for close monitoring. Treatment was initiated with intravenous fluids, pain medications, and an insulin infusion. However, her hypertriglyceridemia levels remained persistently elevated, necessitating therapeutic apheresis. She recovered well with no complications after triglyceride apheresis.

DISCUSSION

AP following pembrolizumab-associated hypertriglyceridemia remains a rare clinicopathologic entity. Given the widespread clinical use of immune checkpoint inhibitors, knowledge of such rare adverse events is crucial. Evaluation of serum triglyceride levels before and after initiating pembrolizumab therapy may be mandated, especially in patients with metabolic comorbidities.

Severity and outcome of a first episode of idiopathic acute pancreatitis is not more severe than pancreatitis of other etiologies

BACKGROUND

With respect to severity and outcome of an index episode of idiopathic acute pancreatitis the current literature reports conflicting retrospective results. One reason might be the retrospective study design precluding in depth analysis resulting in mixed etiologies and combination of index episode versus recurrent idiopathic acute pancreatitis.

METHODS

In this retrospective monocentric cohort study, we retrieved all patients with a first acute pancreatitis episode treated between 2005 and 2021 at the LMU University Hospital from our clinical information system based on the respective ICD-10 codes. In an initial sample of 1390 presumed idiopathic pancreatitis patients we identified 68 confirmed idiopathic acute pancreatitis patients and compared those to 75 first-time alcohol-induced acute pancreatitis patients and 390 first-time biliary-induced acute pancreatitis patients. Clinical outcome (severity, SIRS, mortality, and re-admission rate) was set as outcome measures. Multinomial logistic regression analysis was performed.

RESULTS

In alcohol-induced acute pancreatitis moderate and severe courses occur significantly more often when compared to idiopathic acute pancreatitis (17.33 % vs. 10.29 %; multinomial logistic regression p = 0.0021). There were no significant differences in mortality between first-time alcoholic, idiopathic and biliary pancreatitis (p = 0.6328). Patients with idiopathic acute pancreatitis had significantly more hospital readmissions (within 30 days) compared to alcohol-induced pancreatitis patients (p = 0.0284).

CONCLUSION

In the context of a first episode of acute pancreatitis, idiopathic acute pancreatitis remains a challenging diagnosis posing an increased risk of recurrence, but not an increased risk for a more severe disease course.

Clinical characteristics, imaging diagnostic accuracy, and prognosis of autoimmune pancreatitis: A real-world study in China

OBJECTIVE

In this study we aimed to comprehensively evaluate the clinical features and treatment outcomes of Chinese patients with autoimmune pancreatitis (AIP) through a single-center real-world study.

METHODS

Patients diagnosed with AIP in Changhai Hospital, Naval Medical University from January 2014 to December 2021 were included. Baseline characteristics, laboratory test results, cross-sectional imaging and endoscopic ultrasound (EUS) findings, and long-term follow-up data were obtained. The differences in these characteristics between type 1 and type 2 AIP patients were analyzed.

RESULTS

Among all 320 patients, 271 (84.7%) and 49 (15.3%) had type 1 and type 2 AIP, respectively. The most common initial symptom was abdominal discomfort (58.1%), followed by obstructive jaundice (32.5%). Extrapancreatic organ involvement was identified in 126 (39.4%) patients, with the biliary system being the most commonly involved (36.6%). Elevated serum IgG4 level was rare in type 2 AIP patients. The diagnostic accuracy of computed tomography (CT), magnetic resonance imaging (MRI), and EUS for definitive and probable AIP were 78.0%, 68.7%, and 80.5%, respectively. EUS-guided tissue acquisition with immunohistochemical staining helped establish a final diagnosis in 39.7% of patients. During the follow-up period of 60 months, 18.6% of patients experienced relapse. The 1-, 3-, and 5-year relapse rates were higher in type 1 AIP patients, with an accumulated rate of 8.0%, 12.6%, and 15.1%, when compared with those with type 2 AIP.

CONCLUSIONS

Type 2 AIP is not uncommon in Chinese population. The diagnostic accuracy of CT and EUS for AIP might be superior to that of MRI.