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.

Pancreatic exocrine insufficiency (PEI) is defined as a reduction in pancreatic exocrine secretion below a level that allows normal digestion of nutrients. Pancreatic disease and pancreatic surgery are the main causes of PEI, but other conditions can affect the digestive function of the pancreas.

In collaboration with European Digestive Surgery (EDS), European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), European Society for Clinical Nutrition and Metabolism (ESPEN), European Society of Digestive Oncology (ESDO), and European Society of Primary Care Gastroenterology (ESPCG) the working group developed European guidelines for the diagnosis and therapy of PEI. United European Gastroenterology (UEG) provided both endorsement and financial support for the development of the guidelines.

Recommendations covered topics related to the clinical management of PEI: concept, pathogenesis, clinical relevance, general diagnostic approach, general therapeutic approach, PEI secondary to chronic pancreatitis, PEI after acute pancreatitis, PEI associated with pancreatic cancer, PEI secondary to cystic fibrosis, PEI after pancreatic surgery, PEI after esophageal, gastric, and bariatric surgery, PEI in patients with type 1 and type 2 diabetes, and PEI in other conditions.

The European guidelines for the diagnosis and therapy of PEI provide evidence-based recommendations concerning key aspects of the etiology, diagnosis, therapy, and follow-up, based on current available evidence. These recommendations should serve as a reference standard for existing management of PEI and as a guide for future clinical research. This article summarizes the recommendations and statements.

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.

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.

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.

NCT06328101.

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.

Retroperitoneal fibrosis (RPF) is a rare fibro-inflammatory condition characterized by abnormal tissue growth around the abdominal aorta and iliac arteries, usually encasing adjacent structures like the ureters. Its etiology remains most of the time idiopathic, but secondary causes, including malignancies and medication use, account for a minority of cases. This review aims to consolidate recent advancements in understanding RPF, focusing on its pathophysiology, diagnosis, and treatment. Literature search was conducted using databases like PubMed, with emphasis on recent publications. Biomarkers such as elevated CRP levels and imaging techniques like CT scans and MRI play pivotal roles in diagnosis and monitoring. Medical management primarily revolves around corticosteroids, with adjunctive therapies like tamoxifen and immunosuppressants showing promise. Surgical intervention, typically ureterolysis, becomes necessary in cases of urinary tract obstruction. This review studies the importance of a comprehensive approach to RPF management, integrating medical and surgical modalities for optimal patient outcomes.

Pancreatic exocrine insufficiency (PEI) is defined as a reduction in pancreatic exocrine secretion below the level that allows the normal digestion of nutrients. Pancreatic disease and surgery are the main causes of PEI. However, other conditions and upper gastrointestinal surgery can also affect the digestive function of the pancreas. PEI can cause symptoms of nutritional malabsorption and deficiencies, which affect the quality of life and increase morbidity and mortality. These guidelines were developed following the United European Gastroenterology framework for the development of high-quality clinical guidelines. After a systematic literature review, the evidence was evaluated according to the Oxford Center for Evidence-Based Medicine and the Grading of Recommendations Assessment, Development, and Evaluation methodology, as appropriate. Statements and comments were developed by the working groups and voted on using the Delphi method. The diagnosis of PEI should be based on a global assessment of symptoms, nutritional status, and a pancreatic secretion test. Pancreatic enzyme replacement therapy (PERT), together with dietary advice and support, are the cornerstones of PEI therapy. PERT is indicated in patients with PEI that is secondary to pancreatic disease, pancreatic surgery, or other metabolic or gastroenterological conditions. Specific recommendations concerning the management of PEI under various clinical conditions are provided based on evidence and expert opinions. This evidence-based guideline summarizes the prevalence, clinical impact, and general diagnostic and therapeutic approaches for PEI, as well as the specifics of PEI in different clinical conditions. Finally, the unmet needs for future research are discussed.

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.

Pleural thickening can be the result of inflammation or infection but can also have a neoplastic origin. Depending on the clinical context, a pleural lesion or mass is often initially suspected of malignancy. Benign pleural tumors are rare, and their appearance on ultrasound (US) is also described less frequently than pleural metastases or malignancies. There are few descriptions of contrast-enhanced Ultrasound (CEUS) in particular. This review introduces the basics of transthoracic ultrasound (TUS) of the pleura and CEUS of the pleura and lung. CEUS is recommended for pulmonary applications in the EFSUMB guidelines in non-hepatic applications. This article provides an overview of the characteristics of benign pleural thickening, tumor-like lesions, and benign pleural tumors on transthoracic B-mode US with color Doppler imaging (CDI) and CEUS. In detail, characteristics in TUS and CEUS are described for infectious/inflammatory pleural thickening (empyema, tuberculous pleuritis, hemothorax, fibrothorax), pleural thickening in various systemic diseases, in tumor-like conditions (plaques, splenosis, endometriosis, mesothelial cysts, lymphangiomatosis) and benign tumors (lipoma, benign SFT, schwannoma, solitary extramedullary/extraosseous plasmacytoma). The descriptions are illustrated by corresponding US and CEUS images.

A variety of systemic diseases may affect the gastrointestinal (GI) tract. Since the GI tract responds to injury in limited ways, identifying these processes may be challenging, especially on small endoscopic biopsies. This article reviews the clinicopathologic features of commonly encountered systemic diseases affecting the tubular GI tract: sarcoidosis, graft vs. host disease, mast cell disorders, systemic sclerosis, and IgG-4 related disease. In addition, we offer guidance in differentiating them from their mimics.

The purpose of this review is to examine the current scientific literature regarding the interplay between the exocrine and endocrine pancreas, specifically the role of the exocrine pancreas in the pathogenesis of canine diabetes mellitus. β-cell death caused by exocrine pancreatic inflammation is thought to be an under-recognised contributor to diabetes mellitus in dogs, with up to 30 % of canine diabetic patients with concurrent evidence of pancreatitis at post-mortem examination. Current diagnostics for pancreatitis are imprecise, and treatments for both diseases individually have their own limitations: diabetes through daily insulin injections, which has both welfare and financial implications for the stakeholders, and pancreatitis through treatment of clinical signs, such as analgesia and anti-emetics, rather than targeted treatment of the underlying cause. This review will consider the evidence for exocrine pancreatic inflammation making an active contribution to pancreatic β-cell loss and insulin-deficiency diabetes in the dog and explore current and potential future diagnostic and treatment avenues to improve outcomes for these patients.

Background. IgG4-related disease (IgG4-RD) is a systemic immune-mediated condition characterized by fibro-inflammatory infiltration. It is a rare disease that can affect any organ, with the involvement of the stomach being particularly uncommon. The clinical manifestations of IgG4-RD are highly variable depending on the type and number of organs involved and mirror the symptoms of other conditions. Case presentation. We report a 61-year-old man who presented with symptoms of gastric outlet obstruction and was subsequently diagnosed with IgG4-RD. The patient experienced recurrent vomiting, early satiety, and substantial weight loss. Imaging studies revealed luminal narrowing in the pyloric region, prompting further endoscopic evaluation. Initial endoscopic biopsies were nondiagnostic. Because the patient's clinical symptoms and previous investigations were highly indicative of malignancy, he underwent distal gastrectomy with Roux en Y anastomosis. However, final histopathology revealed lymphoplasmacytic infiltration and dense fibrosis, confirming the diagnosis of IgG4-RD; no malignant cells were noted. The surgery resulted in symptom improvement. Conclusion. This presentation highlights the diagnostic challenges of IgG4-RD with gastric outlet obstruction, emphasizing the significance of a multidisciplinary approach involving clinical, radiological, and histopathological assessments to achieve an accurate diagnosis and develop tailored management strategies.

IgG4 pancreaticobilliary disease (IgG4-PBD) typically shows a rapid improvement with glucocorticoid treatment, yet most patients experience a recurrence. Rituximab (RTX) has emerged as a hopeful approach to prevent relapses in IgG4-PBD. Nevertheless, there is a lack of data on the efficacy and safety of RTX in IgG4-PBD. In this study, we aim to perform a systematic review and meta-analysis to study the pooled efficacy of RTX in this patient population.

Multiple databases, including MEDLINE, SCOPUS, and Embase, were searched (in March 2024) using specific terms for studies evaluating the efficacy and safety of RTX in IgG4 pancreatic biliary disease. Outcomes of interest were relapse, remission, partial remission rates, and adverse events. Standard meta-analysis methods were used using the random-effects model. I2% heterogeneity was used to assess the heterogeneity.

Twelve studies were included in the study (257 patients). The pooled rate of complete remission was 68% (54% to 80%), I2 =53%, respectively. The pooled relapse rate was 23% (13% to 36%), I2=64%. The pooled rate of total adverse events was 21% (12% to 35%), I2=52%. The pooled partial remission rate is 16% (7% to 32%), I2=25%. The pooled rate of complete and partial remission was 81% (66% to 90%), I2=75%. The pooled infusion reaction and infection were 12% (7% to 18%), I2=0% and 14% (8% to 22%), I2=16%, respectively.

RTX therapy appears effective in inducing and maintaining remission of pancreaticobiliary disease with a low rate of side effects. RTX presents as a promising treatment option for patients grappling with recurrent or unresponsive IgG4-related ailments. In addition, RTX emerges as an attractive alternative for individuals intolerant to steroids or experiencing IgG4-related disease relapses. Future studies comparing RTX with other immunomodulators will offer deeper insights into relapse factors and elucidate the appropriateness of utilizing this maintenance treatment following the initial flare.

IgG4-related disease (IgG4-RD) is a recently described multisystemic disorder with a spectrum of manifestations that continue to be described. Nonetheless, there are recognised distinct patterns of disease. Neurological involvement is rare, particularly in isolation, but IgG4-RD may present with orbital disease, hypophysitis or pachymeningitis. Typically, it is highly responsive to treatment. This review highlights neurological manifestations of IgG4-RD and emphasises the importance of a high index of clinical suspicion to facilitate investigation and appropriate management, avoiding irreversible tissue damage and neurological dysfunction. We present a treatment algorithm for suggested management of IgG4-RD affecting the nervous system.

Autoimmune pancreatitis (AIP) is a diagnosis-challenging disease that often mimics pancreatic malignancy. Pancreatic resection is considered to be a curative treatment for pancreatic ductal adenocarcinoma (PDAC). This meta-analysis aims to study the incidence of AIP in patients who have undergone pancreatic resection for clinical manifestation of cancer.

A comprehensive search was conducted in three databases, PubMed, Embase and the Cochrane Library, using the terms 'autoimmune pancreatitis' and 'pancreatic resection' and supplemented by manual checks of reference lists in all retrieved articles.

Ten articles were included in the final analysis. 8917 pancreatic resections were performed because of a clinical suspicion of pancreatic cancer. AIP accounted for 140 cases (1.6%). Type 1 AIP comprised the majority of cases, representing 94% (132 cases), while type 2 AIP made up the remaining 6% (eight cases) after further classification. AIP accounted for almost 26% of all cases of benign diseases involving unnecessary surgery and was overrepresented in males in 70% of cases compared to 30% in females. The mean age for AIP patients was 59 years. Serum CA 19 - 9 levels were elevated in 23 out of 47 (49%) AIP patients, where higher levels were detected more frequently in patients with type 1 AIP (51%, 22 out of 43) than in those with type 2 AIP (25%, 1 out of 4). The sensitivity of IgG4 levels in type 1 AIP was low (43%, 21/49 patients).

Even with modern diagnostic methods, distinguishing between AIP and PDAC can still be challenging, thus potentially resulting in unnecessary surgical procedures in some cases. Serum CA 19 - 9 levels are not useful in distinguishing between AIP and PDAC. Work must thus be done to improve diagnostic methods and avoid unnecessary complicated surgery.

Objectives: Autoimmune pancreatitis (AIP) type 1, paraduodenal (groove) pancreatitis, and follicular pancreatitis are rare clinical entities whose diagnosis may be challenging, given the potential imaging overlap with pancreatic cancer. Methods: We performed a retrospective analysis of the medical chart of a patient with multiple pancreas pathologies. Results: We present a case with multiple pancreas pathologies, including a poorly differentiated ductal adenocarcinoma of pancreatobiliary type, an intraductal papillary mucinous lesion (pre-existing lesion of IPMN type), and an inflammatory process with complex features, in which paraduodenal (groove) pancreatitis, follicular pancreatitis, and IgG4-related pancreatitis (AIP type 1) were also present. Conclusions: The diagnosis of AIP and paraduodenal pancreatitis is not always straightforward, and in some cases, it is not easy to differentiate them from pancreatic cancer. Surgery should be considered in patients when a suspicion of malignant/premalignant lesions cannot be excluded after a complete diagnostic work-up.

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality. Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders, which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries. Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases. In this review, we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations, epidemiology, and aberrant cellular composition involving the biliary ductules, cholangiocytes, immune system, fibroblasts, and the microbiome. We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies. This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

The European Pancreatic Club Lifetime Achievement Award is a distinction awarded for research on the pancreas and service to European Pancreatology. It comes with the obligation to submit a review article to our society's journal, Pancreatology. It was awarded to me 2023 and I take this opportunity to highlight my journey with the central organ AKA the pancreas, that is inseparatable from "Pancreas 2000" - an educational program for future pancreatologists, inaugurated by Karolinska Institutet.

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition causing organ swelling and fibrosis. Rarely, it coexists with primary immune thrombocytopenia (ITP), characterized by low platelet count (< 100 × 106/L) without an underlying cause. We present a case of a 56-year-old woman diagnosed with ITP in 2005, successfully treated with dexamethasone and intravenous immunoglobulins (IVIG). In 2011, she was diagnosed with IgG4-RD, type I autoimmune pancreatitis, initially treated with steroids then azathioprine with no response. ITP relapses were managed with prednisone/IVIG, rituximab, and thrombopoietin-receptor agonist therapy. Fostamatinib provided temporary relief, but platelet count dropped again in 2023. Combination therapy with small doses of prednisone and mycophenolate showed a partial response, maintaining platelet count over 50 × 106/L. Further investigation is warranted to explore any correlation between these two conditions, especially considering the patient's prolonged response to immunosuppressors.

A high prevalence of diabetes mellitus (DM) coexisting with autoimmune pancreatitis (AIP) is observed. However, evidence on the circumstances under which corticosteroid therapy (CST) for AIP improves or worsens DM is scarce. This study aimed to demonstrate and identify predictors of DM control under the influence of CST.

Patients diagnosed with type 1 AIP were enrolled from a prospectively maintained cohort and were classified into three groups according to the chronology in which AIP and DM were diagnosed: pre-existing DM (pDM), concurrent DM (cDM), and non-DM (nDM). The responses of DM to CST were assessed when corticosteroid was ceased or tapered to a maintenance dose and classified as 'improvement' and 'non-improvement' (including 'no change' and 'exacerbation').

Among 101 patients with type 1 AIP, 52 (51.5%) patients were complicated with DM at the time of AIP diagnosis, with 36 patients in the cDM group and 16 patients in the pDM group. The incidences of diffuse pancreatic swelling (72.2%) and pancreatic body/tail involvement (91.7%) were significantly higher in the cDM group than in both the pDM and nDM groups. Of the 52 patients with DM, CST was administered in 48 cases. Multivariate logistic analysis identified that elevated serum gamma-glutamyl transferase (GGT) level at AIP diagnosis [odds ratio (OR) = 0.032, 95% confidence interval (CI): 0.003-0.412, P = 0.008] and pancreatic atrophy after CST (OR = 0.027, 95% CI: 0.003-0.295, P = 0.003) were negatively associated with DM control improvement.

Patients with diffuse pancreatic swelling and pancreatic body/tail involvement in pancreatitis tended to be complicated with cDM at AIP diagnosis. CST exerted a beneficial effect on the clinical course of DM in nearly half of the AIP patients complicated with DM at diagnosis, particularly in those without elevated serum GGT levels at diagnosis and who did not experience pancreatic atrophy after CST.

Patients diagnosed with primary sclerosing cholangitis (PSC) but with characteristics of immunoglobulin G4 (IgG4)-associated cholangitis (IAC) have been described. IAC often presents with biliary IgG4-positive plasma cell (IgG4+ PC) infiltration and responds to corticosteroids. In PSC, the frequencies or implications of biliary IgG4+ PC are unknown. We aimed to characterize the phenomenon of biliary IgG4+ PC in patients with an established PSC diagnosis.

Bile duct biopsies from 191 surveillance or therapeutic endoscopic retrograde cholangiography of 58 PSC patients were retrospectively analyzed for IgG4+ PC infiltration. Patients with ≥10 IgG4+ PC per high-power field (HPF) were identified and characterized by clinical parameters, including serum IgG4 and cholangiographic presentations.

Altogether 39.7% of the PSC patients showed ≥10 IgG4+ PC/HPF in bile duct biopsies. Patients with biliary IgG4+ PC infiltration were significantly younger at diagnosis of PSC (P = 0.023). There was no association between biliary IgG4+ PC infiltration and transplant-free survival (P = 0.618). Patients with IgG4+ PC infiltration in bile duct biopsies showed significantly higher baseline (P = 0.002) and maximum (P = 0.001) serum IgG4 compared to those without. Biliary IgG4+ PC infiltration was associated with high-grade bile duct strictures (P = 0.05). IgG4-positive plasma cell infiltrations were found multifocally in 72.7% of this subgroup of PSC patients.

IgG4+ PC ≥10/HPF can be found abundantly in bile duct biopsies in PSC. Histological findings correlated with serum IgG4, age, and high-grade bile duct strictures. IgG4+ PC was located multifocally, hinting at a systemic biliary phenotype.

A prompt response to glucocorticoids is a clinical hallmark of IgG4-related disease. However, manifestations characterised by prominent tissue fibrosis on histological examination can be less responsive to glucocorticoid therapy than other types of IgG4-related disease. These manifestations include retroperitoneal fibrosis, fibrosing mediastinitis, Riedel thyroiditis, orbital pseudotumor, and hypertrophic pachymeningitis, among others. To explain this discrepancy, a preliminary distinction into proliferative and fibrotic phenotypes of IgG4-related disease has been proposed on the basis of clinical presentation, pathological features, and response to immunosuppressive therapy. Implications of this classification for patient management remain an important area of investigation. In this Series paper, we aim to dissect the pathophysiology of tissue fibrosis in IgG4-related disease and discuss how clinicians should approach the management of fibrotic manifestations of IgG4-related disease based on the most recent diagnostic and therapeutic developments.

IgG4-related disease is an immune-mediated disease that can lead to substantial morbidity and organ damage. Capable of affecting nearly any organ system or anatomic site, and showing considerable overlap in clinical presentation with various other diseases, IgG4-related disease often poses a diagnostic challenge for clinicians. Furthermore, there are no diagnostic biomarkers with high specificity for IgG4-related disease, and histopathological examination is nuanced and requires clinical correlation for accurate diagnosis. Therefore, it is crucial for clinicians to recognise the clinical phenotypes of IgG4-related disease. The disease is generally considered to have predominantly fibrotic and proliferative (or inflammatory) manifestations, with distinct clinical, serological and histopathological findings associated with each manifestation. However, the fibrotic and proliferative manifestations of this disease frequently occur together, thereby blurring this dichotomous distinction. In this Series paper, we provide a detailed overview of the clinical manifestations typical of the proliferative features of IgG4-related disease, with an emphasis on the diagnostic evaluation and differential diagnosis of each proliferative disease manifestation. In addition, we summarise the immune mechanisms underlying IgG4-related disease, suggest a framework for how to approach management and monitoring after the diagnosis is established, and highlight current unmet needs for patient care surrounding this disease.

Autoimmune pancreatitis (AIP) is a unique form of chronic pancreatitis with a multifactorial pathogenesis. Historically, it has been classified as type 1 and type 2, according to its clinical and histological features. The diagnosis of AIP is challenging and relies on a combination of clinical, histopathologic, serologic, and imaging characteristics. In the available guidelines, the imaging hallmarks of AIP are based on cross-sectional imaging and cholangiopancreatography retrograde endoscopic findings. Endoscopic ultrasound (EUS) is generally used for pancreatic tissue acquisition to rule out pancreatic cancer and diagnose AIP with limited accuracy. Several papers reported the reliability of EUS for providing informative morphologic features of AIP. Nowadays, the improvement in the resolution of EUS conventional images and the development of new ancillary technologies have further increased the diagnostic yield of EUS: contrast-enhanced EUS and EUS elastography are non-invasive and real-time techniques that strongly support the diagnosis and management of pancreatic diseases. In this review article, we will present the role of conventional EUS and ancillary diagnostic techniques in the diagnosis of AIP to support clinicians and endosonographers in managing this condition.

IgG4-related disease (IgG4-RD) is a rare disease entity in India. We aimed at studying the clinical profile of IgG4-RD of gastrointestinal tract (GIT) from our centre, while systematically reviewing data from India.

Retrospective review of IgG4-RD of GIT was done using electronic medical records between January 2013 and July 2022. Literature search was done for studies of IgG4-RD of the GIT reported from India from 2000 till January 2023. Case series, case reports of IgG4-RD of GIT and case reports describing GIT with multi-organ involvement were included in the review. Primary outcome measure was response to treatment. Secondary outcome measure was relapse after remission.

Thirty-one patients were included with 71% (22/31) having autoimmune pancreatitis. The diagnosis was achieved on surgical specimen in 35% (11/31) patients. Steroid was given to 64% (20/31) patients with remission achieved in 70% (14/20) patients. Four patients exhibitted response to prolonged course of steroids with maintenance azathioprine. Relapse was seen in four (20%) patients who achieved remission. Of 731 articles screened, 48 studies (four case series and 44 case reports) were included in the literature review. Of 95 patients described, steroids were given to 65.2% (62/95), while surgery was done in 33.6% (32/95). Remission was seen in 96.6% (85/88) with relapse occurring in 11.4% (10/88) patients on follow-up.

One-third patients of IgG4-RD of GIT are diagnosed after surgery. Response to steroids is good with relapse occurring in up to 12% patients.

This research investigated the impacts of lycium barbarum polysaccharide (LBP) on the digestive function, intestinal mucosal barrier function, inflammatory response, and myosin light chain kinase (MLCK) signaling pathway in immunosuppressed mice. 70 mg/kg cyclophosphamide was injected into abdomen for the preparation of immune suppression model. Healthy BALB/c mice served as control for the analysis of the differences in gastrointestinal motility and absorptive capacity, intestinal mucosal barrier function, the phagocytic ability of abdominal macrophages, serum immune factor and inflammatory factor levels, and the activation status of the MLCK signaling pathway after continuous gavage with 100 mg/kg LBP. Results revealed a decrease in d-xylose content, phagocytic rate, index of abdominal macrophages, and spleen index in the serum and urine of model mice compared to those of controls. In addition, levels of IgA, IgG, IgM, IL-6 (interleukin-6), IL-12, and interferon-γ (IFN-γ) decreased, while MLCK and myosin light chain (MLC) levels rose (P < 0.01). Versus those in Model group, urine d-xylose content, phagocytic rate, index of abdominal macrophages, spleen index, and the levels of IgA, IgG, IgM, IL-6, IL-12, and IFN-γ of mice undergoing the gavage with LBP increased, while MLCK and p-MLC levels declined (P < 0.05). In conclusion, LBP improved digestive absorption and immune function of immunosuppressed mice and regulated intestinal mucosal barrier immune system by inhibiting MLCK signaling pathway activation.

Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens.

We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary end point was complete remission, defined as the absence of clinical symptoms and resolution of the index radiologic pancreatic abnormalities attributed to AIP.

We included 735 individuals with AIP (69% male; median age, 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, whereas 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (odds ratio, 0.428; 95% confidence interval, 0.054-3.387) and neither was a starting dose duration >2 weeks (odds ratio, 0.908; 95% confidence interval, 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (odds ratio, 0.639; 95% confidence interval, 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid-tapering duration, induction treatment duration, and total cumulative dose.

Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.

Autoimmune Pancreatitis (AIP) is a rare chronic inflammatory disease affecting the pancreas. Chronic pancreatic inflammation represents a risk factor for pre-neoplastic conditions such as Intraductal Papillary Mucinous Neoplasia (IPMN). Due to the rarity of AIP, the incidence, and clinical features of IPMN occurring in AIP patients remains unknown.

In the present study we aimed to explore the relationship between AIP and IPMN and to characterize the clinical features and outcomes of IPMN occurring in the context of AIP.

We retrospectively (2008-2020) analyzed the clinical and radiological records of a large single center cohort of patients with AIP and investigated the prevalence of IPMN. We then compared the clinical, laboratory and radiological characteristics of patients with IPMN and AIP with a cohort of patients with isolated IPMN.

Five hundred and nineteen patients were included in this retrospective study. Sixteen patients had concomitant IPMN and AIP(3%); 61 patients had isolated AIP (12%); 442 patients had isolated IPMN (85%). The prevalence of IPMN in patients with AIP was higher than that observed in the general population (21%vs8-10%). Worrisome Features and High-Risk Stigmata were more frequently observed in IPMN occurring together with AIP compared to isolated IPMN(p < 0.05). Based on radiological features IPMN in the context of AIP was more frequently of main-duct type compared to isolated IPMN(p < 0.05).

Our data suggest that AIP represents a chronic inflammatory condition that might favor IPMN development with high-risk features. Prolonged surveillance of these patients and longitudinal studies are required to further test the association with AIP and malignant and pre-malignant conditions.

IgG4-related disease is a rare and emerging pathology, characterized by the appearance of pseudotumors. Due to the ability to mimic other pathologies, it is essential to consider it as a differential diagnosis in multisystemic processes. The diagnosis is challenging, requiring a multidisciplinary approach, to minimize the associated morbidity and mortality.

IgG4-related disease (IgG4-RD) is a rare, emerging, systemic and chronic pathology, characterized by the appearance of pseudotumors resulting from tissue infiltration by IgG4-positive plasma cells that promote eosinophilic inflammation of the tissue with subsequent fibrosis. We present the case of a male, 45-year-old patient, with marked weight loss and skin pallor detected by his family doctor during a child health consultation of his daughter. When questioned, the patient referred complaints of postprandial discomfort in the left hypochondrium with a feeling of fullness, weight loss, chronic fatigue and hyperhidrosis that had lasted for a month. On physical examination, he was pale, and had pain at palpation of the left hypochondrium. Laboratory data showed increased inflammation markers, abdominal ultrasound and CT demonstrated numerous enlarged lymph nodes in the upper quadrants, raising concern for a malignant lymphoproliferative process. Serological, imaging, clinical and laparoscopic excisional biopsy revealed features of IgG4-related disease and excluded malignant lymphoproliferative disease. The immediate response to treatment with oral prednisolone 30 mg/day also contributed for diagnosis confirmation. Due to refractory disease after gradual prednisolone reduction, second-line therapy with rituximab was initiated. Over the 6 years of follow-up, the patient presented multiple exacerbations characterized by the emergence of systemic symptoms, being maintained under close clinical and imaging follow-up by reumathology, infectious diseases, and family medicine specialists.

The etiology of primary sclerosing cholangitis (PSC) remains unclear, which explains in part the lack of a causal treatment. The differential diagnostic distinction from the even rarer immunoglobulin 4 (IgG4)-associated cholangitis (IAC) is becoming increasingly more successful. Advances in the understanding of different clinical courses, improvements in noninvasive diagnostics through modern magnetic resonance imaging (MRI) and the introduction of liver elastography have led to the development of improved prognostic models. The evidence for recommendations on medicinal (e.g., ursodeoxycholic acid) or endoscopic treatment (e.g., balloon dilatation and/or stent insertion) for PSC is still low. In contrast, the long-term results of liver transplantation in PSC patients are constantly improving. Due to the lack of highly sensitive and specific screening methods the early recognition of cholangiocellular carcinoma (CCC) as the most important complication is rarely successful. The continuous improvement of endoscopic retrograde cholangiopancreatography (ERCP) and direct cholangioscopy in combination with molecular biological and fluorescence in situ hybridization (FISH) analyses of bile duct tissue samples are promising for refined diagnostics. Due to the significantly increased risk of colorectal cancer, an annual colonoscopy is recommended in the presence of inflammatory bowel disease. Improvement of the early diagnostics of PSC and successful testing of new treatment strategies raise hope for a continuous improvement in the medical support of these complex patients.

IgG4-related cholangitis (IRC) is the hepatobiliary manifestation of IgG4-related disease. Anti-laminin 511-E8 autoantibodies have been identified in its pancreatic manifestation. Laminin 511-E8 promotes endothelial barrier function, lymphocyte recruitment, and cholangiocyte differentiation. Here, we investigate anti-laminin 511-E8 autoantibody presence in IRC, and mechanisms via which laminin 511 may contribute to cholangiocyte protection.

Anti-laminin 511-E8 serum autoantibody positivity was assessed by ELISA. RNA sequencing and RT-qPCR were performed on human H69 cholangiocytes treated with recombinant laminin 511-E8. H69 cholangiocytes were subjected to shRNA knockdown targeting genes encoding laminin 511 (LAMA5, LAMB1, LAMC1) or treated with recombinant laminin 511-E8. Cholangiocellular bile acid influx was quantified radiochemically using 22,23-3H-glycochenodeoxycholic acid (GCDC). GCDC-induced apoptosis was determined by Caspase-3/7 assays. Cholangiocellular barrier function was assessed by FITC-Dextran permeability assays. Immunofluorescent staining of laminin 511 and claudin 1 was performed on extrahepatic bile duct tissue of control and anti-laminin 511-E8 positive individuals with IRC.

Seven out of 52 individuals with IRC had autoantibodies against laminin 511-E8. Recombinant laminin 511-E8 led to differential expression of genes involved in secretion, barrier function, and inflammation. Knockdown of laminin 511 constituents increased toxic bile acid permeation and GCDC-induced apoptosis. Laminin 511-E8 treatment decreased toxic bile acid permeation and dose-dependently alleviated GCDC-induced apoptosis. LAMA5 and LAMC1 knockdown increased transepithelial permeability. Laminin 511-E8 treatment reduced transepithelial permeability and prevented T lymphocyte-induced barrier dysfunction. Laminin 511 and claudin 1 staining patterns appeared altered in anti-laminin 511-E8 positive individuals with IRC.

Laminin 511-E8 is an autoantigen in subsets of individuals with IRC. Laminin 511 enhances cholangiocellular barrier function and protects cholangiocytes against T lymphocyte-induced barrier dysfunction, toxic bile acid permeation and bile acid-induced apoptosis.

A subset of patients with IgG4-related cholangitis (IRC) has autoantibodies against laminin 511-E8. In human cholangiocytes, laminin 511 protects against (T lymphocyte-induced) epithelial barrier dysfunction and hydrophobic bile acids. Laminin 511 and claudin 1 staining may be altered in extrahepatic bile ducts of patients with IRC who are anti-laminin 511-E8 positive. This makes it tempting to speculate that a decreased epithelial barrier function with attraction of immune cells and impaired bicarbonate secretion as a result of dysfunction of laminin 511 by autoantibody binding could potentially be a common systemic pathogenic mechanism in a subset of patients with IgG4-RD.

The impact of extended steroid administration on patients with autoimmune pancreatitis after a 3-year maintenance period remains poorly understood. This study analyzed the advantage and disadvantage of continuing steroid therapy beyond 3 years.

In this retrospective multicenter study across 17 institutions, patients who successfully completed 3 years of maintenance therapy without experiencing relapse were categorized into two groups: the maintenance therapy discontinuation group, who discontinued steroid therapy after the initial 3-year period, and maintenance therapy continuation group, who continued steroid therapy beyond 3 years. The cumulative relapse rate after 3 years of maintenance therapy was the primary outcome. Relapse predictors were compared using the Gray test for cumulative relapse incidence by specific factor.

Of 211 patients, 105 experienced no relapse during the 3-year maintenance therapy and were divided into two groups: 69 in the maintenance therapy discontinuation group and 36 in the maintenance therapy continuation group. The relapse rate was lower in the maintenance therapy continuation group than in the maintenance therapy discontinuation group (P = 0.035). Predictors of relapse after 3 years included cessation of maintenance therapy (hazard ratio [HR] = 3.76; 95 % confidence interval [CI] = 1.07-13.3, P = 0.040) and renal involvement (HR = 2.88; 95 % CI = 1.04-7.99, P = 0.042). The maintenance therapy continuation group showed a significantly higher prevalence of macrovascular complications, compared with the maintenance therapy discontinuation group (P = 0.005).

Cessation of steroid maintenance therapy and renal involvement were predictors of relapse after 3 years of maintenance therapy. However, the long-term use of steroids may increase the risk of macrovascular complications.

IgG4-related disease (IgG4-RD) is a relatively novel fibroinflammatory condition characterized typically by dense lymphoplasmacytic inflammation, storiform fibrosis and obliterative venulitis, together with prominent IgG4+ plasma cells and an IgG4+/IgG+ plasma cell ratio of >40 %. The diagnosis is usually made on a combination of clinical and serological features together with characteristic radiological and histological appearances. The condition may be limited to a single tissue/organ (e.g., autoimmune pancreatitis) or may be multicentric in nature - four clinical 'patterns' of disease distribution have recently been described. The diagnosis of IgG4-RD can be challenging, particularly when the clinical presentation is unusual and/or when the histological features are not typical. A diagnosis of IgG4-RD may still be achieved in these situations, after careful clinicopathological discussion e.g., at a specialist multidisciplinary team meeting. However, a wide range of other conditions (neoplastic and non-neoplastic) can mimic IgG4-RD, clinically and/or on histological examination. The relationship between IgG4-RD and non-IgG4-RD associated conditions in some clinical situations is particularly complex. This review describes the role of histological examination in the diagnosis of IgG4-RD, discusses some of the practical difficulties that may be encountered and provides an insight into the range of non-IgG4-RD associated conditions that can mimic IgG4-RD on clinical and/or histological grounds. The requirement for interpretation of histological features in the context of the global clinical picture of the patient is highlighted and emphasized.

Autoimmune pancreatitis (AIP) is an autoimmune subtype of chronic pancreatitis resulting from the aberrant immune response against the pancreas, leading to inflammation and fibrosis. Although AIP is rare, its incidence is increasing and is often misdiagnosed as other pancreatic diseases. AIP is commonly classified into two types. Type 1 AIP (AIP-1) is typically associated with elevated serum immunoglobulin G4 (IgG4) levels and systemic manifestations, while type 2 AIP is typically a more localized form of the disease, and may coexist with other autoimmune disorders, especially inflammatory bowel diseases. Additionally, there is emerging recognition of a third type (type 3 AIP), which refers to immunotherapy-triggered AIP, although this classification is still gaining acceptance in medical literature. The clinical manifestations of AIP mainly include painless jaundice and weight loss. Elevated serum IgG4 levels are particularly characteristic of AIP-1. Diagnosis relies on a combination of clinical, laboratory, radiological, and histological findings, given the similarity of AIP symptoms to other pancreatic disorders. The mainstay of treatment for AIP is steroid therapy, which is effective in most cases. Severe cases might require additional imm-unosuppressive agents. This review aims to summarize the current knowledge of AIP, encompassing its epidemiology, etiology, clinical presentation, diagnosis, and treatment options. We also address the challenges and controversies in diagnosing and treating AIP, such as distinguishing it from pancreatic cancer and managing long-term treatment, highlighting the need for increased awareness and knowledge of this complex disease.

Emerging cancer trends suggest an increase in pancreatic cancer incidence in individuals younger than its typical age of onset, potentially reflecting changes in population exposures and lifestyles.

We conducted a PRISMA-standard systematic literature review to identify non-heritable risk factors for early-onset pancreatic ductal adenocarcinoma (PDAC) (PROSPERO number: CRD42022299397). Systematic searches of MEDLINE and Embase bibliographic databases were performed (January 2022), and publications were screened against predetermined eligibility criteria; data were extracted using standardised data fields. The STROBE checklist was used to assess the completeness of reporting as a proxy for publication quality. Data were categorised by risk factor and analysed descriptively.

In total, 24 publications were included. All publications reported observational study data; thresholds for age group comparisons ranged between 40 and 65 years. Lifestyle factors investigated included smoking, alcohol consumption, obesity, physical inactivity, meat intake, socioeconomic status and geographical residence. Clinical factors investigated included pancreatitis, diabetes/insulin resistance, prior cancer and cancer stage at diagnosis, hepatitis B infection, metabolic syndrome and long-term proton pump inhibitor exposure. Publication STROBE scores were 6-21 (maximum, 22). Eight studies reported results adjusted for confounders. Potential non-heritable risk factors for early-onset PDAC that warrant further investigation included smoking, alcohol consumption, pancreatitis and hepatitis B infection.

Evidence for non-heritable risk factors for early-onset PDAC is heterogeneous, but four factors were identified that might aid the identification of at-risk individuals who may benefit from screening and risk reduction strategies.