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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.

Membranous nephropathy (MN) is a common cause of adult-onset nephrotic syndrome. It is also known as a minor but established renal manifestation of Immunoglobulin G4-related disease (IgG4-RD). Previous reports suggest that MN can also be an initial manifestation of IgG4-RD, all of which are phospholipase A2 receptor (PLA2R)-negative MN. We describe a case of PLA2R-positive MN that subsequently developed other manifestations of IgG4-RD. A 60-year-old male with nephrotic syndrome was diagnosed as primary MN with positive staining for PLA2R on the initial renal biopsy, which remained in partial remission with supportive therapy using angiotensin II receptor blocker (ARB) without steroid. About 1 year later, a renal mass was detected during an annual checkup, and contrast-enhanced computed tomography revealed low-density masses in bilateral kidneys and the head of the pancreas. The findings of endoscopic biopsy of the pancreatic mass were consistent with autoimmune pancreatitis (AIP) and the second renal biopsy showed the findings of MN with tubulointerstitial nephritis, both of which led to a diagnosis of IgG4-RD. The second renal biopsy also showed positive PLA2R. The patient received oral glucocorticoid therapy for IgG4-RD, which improved IgG4-related AIP and renal masses and also resulted in complete remission of MN. To our knowledge, this is the first reported case of PLA2R-positive MN with subsequent development of IgG4-RD. It is sometimes difficult to determine whether PLA2R-positive MN occurring with IgG4-RD is primary MN or secondary MN associated with IgG4-RD. The possibility of developing IgG4-RD should be considered even when preceding MN is PLA2R-positive, suggesting of primary MN., (© 2024. The Author(s).)

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., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Enhanced IgG4 antibody (Ab) response is a prominent feature of type 1 autoimmune pancreatitis (AIP). Innate immune responses associated with IgG4 Ab production are poorly defined. We have previously reported that peripheral blood mononuclear cells (PBMCs) isolated from patients with type 1 AIP produce large amounts of IgG4 Abs upon stimulation with bacterial cell wall components. In addition, we showed that activation of plasmacytoid dendritic cells producing interferon (IFN)-α, interleukin (IL)-33, and B cell-activating factor (BAFF) upon sensing intestinal bacteria mediates the development of experimental AIP. In this study, we attempted to clarify the role of innate immunity against fungi in inducing enhanced IgG4 Ab responses in type 1 AIP. PBMCs isolated from healthy controls and patients with type 1 AIP were stimulated with a broad range of bacterial and fungal cell wall components. The concentrations of IgG1, IgG4, and cytokines were measured using enzyme-linked immunosorbent assays. Cell wall components derived from bacteria and fungi induced IgG1 and IgG4 Ab production in patients with type 1 AIP. Various types of microbe-associated molecular pattern motifs enhanced IgG4 Ab production in patients with type 1 AIP compared with the limited motifs in healthy controls. The enhanced IgG1 and IgG4 Ab production that followed in response to bacterial and fungal cell wall components was parallel to that of IFN-α, IFN-γ, IL-10, IL-33, and BAFF. In conclusion, cell wall components derived from fungi as well as bacteria promote IgG4 Ab responses in patients with type 1 AIP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., (© 2024 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.)

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.

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 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., (© 2024. Japanese Society of Gastroenterology.)

To our best knowledge, the formation of a pancreatico-renal fistula and the presence of pancreatic fluid collection in the renal subcapsular space have not been reported as autoimmune pancreatitis (AIP) complications. We describe a case of a pancreatico-renal fistula associated with type 1 AIP. The patient presented with abdominal and back pain accompanied by pancreatic cystic lesions during an untreated course of AIP. The diagnosis of pancreatico-renal fistula was based on the presence of a left renal subcapsular fluid collection containing pancreatic amylase, disappearance of pancreatic cysts, and a defect in the partial anterior renal fascia observed on imaging studies. Treatment with steroids and percutaneous drainage resulted in improvement. Pancreatic pseudocysts can affect other organs owing to their digestive action. Similar symptoms may occur in patients with AIP., (© 2024. Japanese Society of Gastroenterology.)

Immunoglobulin G4-related disease (IgG4-RD) is a rare immune-mediated disease affecting multiple organs and tissues. There is often the presence of elevated serum Ig4 subtype with histological evidence of lymphoplasmacytic infiltration, fibrosis, and phlebitis. The mainstay of treatment is steroid therapy. This case report is based on a 24-year-old man with IgG4-related type 1 autoimmune pancreatitis (AIP) who also had elevated serum IgG4 subclass and histological features in keeping with IgG4-RD. The main complaints were dry cough, nasal congestion with sneezing, sore throat, and fever. Necessary investigations were performed and based on the International Consensus Diagnostic Criteria, the diagnosis of AIP type 1 was confirmed, which is a pancreatic manifestation of IgG4-RD. He was subsequently treated with prednisolone and azathioprine and is showing a good response to the treatment., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Gor et al.)

Autoimmune pancreatitis type 2 is a relatively novel entity with some still controversial issues. The current diagnostic algorithm relies on imaging studies and histology. Therapy includes corticosteroids with consequently low risk of relapse in the following year. However, the pathogenesis remains unclear, and data are insufficient for long-term prognosis. We have treated a 17-year-old boy whose autoimmune pancreatitis type 2 was revealed during surgery for a pre-existing biliary tract anomaly with concurrent protozoal infection. We discuss the co-occurrence of these conditions in terms of eventual pathogenesis correlation and combined effect on long-term prognosis.

Diet-related cardiometabolic diseases and inflammatory bowel disease, common previously in Western countries, are global problems. We hypothesized that inflammatory bowel disease is a lifestyle disease primarily mediated by the current Western diet. We report here the simultaneous onset of ulcerative colitis and autoimmune pancreatitis, a rare systemic complication of inflammatory bowel disease, 2 months after acute myocardial infarction in a patient with type 2 diabetes. A 67-year-old man with type 2 diabetes was referred to us because of newly diagnosed ulcerative colitis 2 months after acute myocardial infarction. A plant-based diet was provided during hospitalization. An abrupt deterioration in plasma glucose and hemoglobin A1c due to asymptomatic type 2 autoimmune pancreatitis was observed. Prednisolone administration under intensive insulin therapy led to the remission of both diseases. This case was an illustrative one of association between cardiometabolic diseases and inflammatory bowel diseases caused by current unhealthy diets and their shared pathogenesis., Competing Interests: • Conflicts of Interest: No conflict of interest., (© 2024 Journal of Lifestyle Medicine.)

Radiologists play a key role in establishing an early and accurate diagnosis, especially for rare diseases. Mahvash disease (OMIM 619290) is an autosomal recessive hereditary disease caused by inactivating mutations of the glucagon receptor and its main clinical consequences are pancreatic neuroendocrine tumors and in some cases, porto-sinusoidal vascular disease and portal hypertension. Untreated Mahvash disease can be lethal. The diagnosis of Mahvash disease has almost always been delayed in the past due to radiologists' unawareness of or unfamiliarity with the unique imaging features of Mahvash disease which are moderately to enormously enlarge pancreas with preserved pancreas contour and parenchyma without vascular involvement or lymphadenopathy. These features help differentiate Mahvash disease from other etiologies of diffusely enlarged pancreas such as diffuse pancreatic ductal carcinoma, diffuse pancreatic lymphoma, and autoimmune pancreatitis. Invoking Mahvash disease in the differential diagnosis of an enlarged pancreas has recently been shown to facilitate early diagnosis. To prevent missing the diagnosis of this significant disease, I sincerely ask radiologists to consider Mahvash disease in their differential diagnoses of diffusely enlarged pancreas., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflict of interest., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: The complexity of immunoglobulin G4 (IgG4)-related diseases and their potential connection to hematologic malignancies remains unclear. This article provided a review of the diagnosis and treatment of a patient with IgG4-related sclerosing cholangitis (SC) and essential thrombocythemia (ET), along with an analysis of relevant literature to enhance comprehension of this disease., Case Summary: A 56-year-old male was admitted to two hospitals with deteriorating jaundice and pruritus prior to hospitalization. Beyond our expectations, the patient was first diagnosed with IgG4-SC and ET with the Janus kinase 2 V617F mutation. Interestingly, the administration of acetate prednisone significantly resulted in improvements in both IgG4-SC and ET. Clinicians need to pay attention to immune disorders and inflammation as they contribute to the development of various disease phenotypes., Conclusion: When IgG4-SC is suspected without histopathological evidence, diagnostic therapy and long-term regular follow-up can lead to positive treatment outcomes. Clinicians should be mindful of the potential presence of concurrent hematologic diseases in patients with immune disorders., Competing Interests: Conflict-of-interest statement: The authors declare that there is no conflict of interest., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background/objectives: 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., Methods: 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., Results: 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)., Conclusion: 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., (© 2024. The Author(s).)

Background: Autoimmune pancreatitis (AIP) is a chronic form of pancreatitis characterized by diffused enlargement of the pancreas and irregular stenosis of the main pancreatic duct. Some studies have reported that AIP can cause hemorrhage of gastric varices (GV) related to portal hypertension (PH). However, such cases are rare. In addition, the association of PH with AIP is unclear. At the same time, the efficacy and duration of glucocorticoid therapy is also controversial., Case Summary: In this case, we reported a case of GV in pancreatic PH associated with AIP. Enhanced abdominal computed tomography (CT) suggested splenic vein (SV) and superior mesenteric vein (SMV) thromboses. The patient received a long-term glucocorticoid therapy, that the initial dose of 40 mg is reduced weekly by 5 mg, and then reduced to 5 mg for long-term maintenance. CT and gastroscopic examination after 8 mo of treatment indicated that SV and SMV were recanalized, pancreatic stiffness and swelling were ameliorated, and the GV almost completely disappeared., Conclusion: Long-term glucocorticoid therapy can alleviate the development of GV in patients with AIP and has potential reversibility., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

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.

Objectives: This study aims to evaluate the utility of F-18 FDG PET/CT in the non-invasive diagnosis of autoimmune pancreatitis (AIP) and differentiating it from pancreatic cancer (CaP) based on the amount and pattern of FDG uptake, as well as involvement of extra-pancreatic sites., Methods: A systematic search was conducted using PubMed, Scopus, Cochrane Library and Google Scholar. Only those studies that compared the findings of F-18 FDG PET/CT in terms of SUVmax, pattern of FDG uptake and presence of FDG-avid extra-pancreatic sites in both AIP and CaP were included. Studies were qualitatively assessed for risk of bias and publication bias. The diagnostic performance of parameters on PET/CT was examined through pooled sensitivity, specificity, diagnostic odd's ratio (DOR) and summary receiver operator characteristic (SROC) curve analysis., Results: Six studies were included with a total of 580 patients. 178 patients had AIP (Age 18-90 years, male, M: female, F ratio-8.4:1) and 402 patients had CaP (Age 22-88 years, M:F ratio-1.5:1). Type of AIP was reported in only 3 studies, with the included cases predominantly being type 1 AIP. All studies were retrospective with heterogeneity and a risk on patient selection and index test. The FDG uptake, expressed as SUVmax, was lower in AIP with a weighted mean difference of -3.11 (95% confidence interval, CI: -5.28 to -0.94). To diagnose AIP, the pooled sensitivity, specificity and DOR of diffuse pattern of FDG uptake were 0.59 (95% CI: 0.51-0.66), 0.89 (95% CI: 0.86-0.92) and 21.07 (95% CI: 5.07-88.32), respectively, with an area under curve (AUC) of 0.717 on SROC analysis. The pooled sensitivity, specificity and DOR of FDG-avid extra pancreatic sites were 0.55 (95% CI: 0.45-0.65), 0.58 (95% CI: 0.52-0.64) and 2.33 (95% CI: 1.40-3.89), respectively, with an AUC of 0.632., Conclusion: On F-18 FDG PET/CT, a pancreatic lesion of AIP has a lower SUVmax value than CaP. A diffuse pattern of FDG uptake and presence of an extra-pancreatic FDG-avid site are nearly 21 times and twice more likely in AIP than CaP, respectively., (© 2024. The Author(s), under exclusive licence to The Author(s) under exclusive licence to The Japanese Society of Nuclear Medicine.)

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.

We report a case of a 44-year-old male patient, who presented to the University Hospital of Salzburg, Austria with abdominal pain, persistent jaundice, and lack of appetite. Radiological work-up (CT, MRI, PET/CT) indicated a suspicious mass of the uncinate process of the pancreatic head with adjacent infiltration and regional lymphadenopathy. The differential diagnosis was between primary pancreatic cancer and focal autoimmune pancreatitis. Further laparoscopic biopsies from multiple areas, showed only fibrous scarring processes, with no malignancy. Treatment with steroids didn't give any benefits. After multiple follow-up CTs and MRs within 6 months-additional biopsies were done, which eventually demonstrated adenocarcinoma. Evidently the cancer diagnosis was much delayed and the patient started receiving chemotherapy, but radical surgery was not possible. Multiple articles and case reports can be found in the literature, that are reviewing the fact that pancreatic inflammatory processes are mimicking pancreatic tumor, but not many articles or case reports are available in the literature, where neoplastic processes are misinterpreted as inflammatory and incorrectly proven with histological examination. One of the main reasons for improper diagnosis is the desmoplastic reaction around the pancreatic malignancy. Another important aspect is the acceptance of histological diagnosis as conclusive, where no opposing arguments are specified, based on radiological criteria., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

Background/objectives: Autoimmune pancreatitis (AIP) is a steroid-responsive inflammatory disease of the pancreas. Few studies investigated pancreatic exocrine function (PEF) in patients suffering from AIP and no definitive data are available on the effect of steroids in PEF recovery. Aim of the study is the evaluation of severe pancreatic insufficiency (sPEI) prevalence in AIP at clinical onset and after steroid treatment., Methods: 312 Patients with diagnosis of AIP between January 1st , 2010 and December 31st , 2020 were identified in our prospectively maintained register. Patients with a pre-steroid treatment dosage of fecal elastase-1 (FE-1) were included. Changes in PEF were evaluated in patients with available pre- and post-treatment FE (between 3 and 12 months after steroid)., Results: One-hundred-twenty-four patients were included, with a median FE-1 of 122 (Q1-Q3: 15-379) μg/g at baseline. Fifty-nine (47.6 %) had sPEI (FE-1<100 μg/g). Univariable analysis identified type 1 AIP, radiological involvement of the head of the pancreas (diffuse involvement of the pancreas or focal involvement of the head), weight loss, age and diabetes as associated with a greater risk of sPEI. However, at multivariable analysis, only the involvement of the head of the pancreas was identified as independent risk factor for sPEI. After steroids, mean FE-1 changed from 64 (15-340) to 202 (40-387) μg/g (P = 0.058) and head involvement was the only predictor of improvement of sPEI., Conclusion: The inflammatory involvement of the head of the pancreas is associated with PEF severity, as well as PEF improvement after treatment with steroids in patients with AIP., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: 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., Methods: 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., Results: 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., Conclusion: 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., (© 2023. Indian Society of Gastroenterology.)

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.

Background/objectives: The association between autoimmune pancreatitis (AIP) and pancreatic cancer (PC) remains controversial. This study aimed to clarify the long-term prognosis and risk of malignancies in AIP patients in Japan., Methods: We conducted a multicenter retrospective cohort study on 1364 patients with type 1 AIP from 20 institutions in Japan. We calculated the standardized incidence ratio (SIR) for malignancies compared to that in the general population. We analyzed factors associated with overall survival, pancreatic exocrine insufficiency, diabetes mellitus, and osteoporosis., Results: The SIR for all malignancies was increased (1.21 [95 % confidence interval: 1.05-1.41]) in patients with AIP. Among all malignancies, the SIR was highest for PC (3.22 [1.99-5.13]) and increased within 2 years and after 5 years of AIP diagnosis. Steroid use for ≥6 months and ≥50 months increased the risk of subsequent development of diabetes mellitus and osteoporosis, respectively. Age ≥65 years at AIP diagnosis (hazard ratio [HR] = 3.73) and the development of malignancies (HR = 2.63), including PC (HR = 7.81), were associated with a poor prognosis, whereas maintenance steroid therapy was associated with a better prognosis (HR = 0.35) in the multivariate analysis. Maintenance steroid therapy was associated with a better prognosis even after propensity score matching for age and sex., Conclusions: Patients with AIP are at increased risk of developing malignancy, especially PC. PC is a critical prognostic factor for patients with AIP. Although maintenance steroid therapy negatively impacts diabetes mellitus and osteoporosis, it is associated with decreased cancer risk and improved overall survival., Competing Interests: Declaration of competing interest None., (Copyright © 2024 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

The incidence of IgG4-related autoimmune pancreatitis (IgG4-AIP) is high in Asia and other countries, and unnecessary treatment is often undertaken due to both missed diagnosis and misdiagnosis in clinical practice. Although IgG4-AIP has attracted increasing attention, the details of IgG4-AIP pathogenesis and systemic immune response, including its relationship to tumor pathogenesis, are still unclear. In recent years, research on serum immunological detection, pathological features, clinical manifestations, diagnosis and treatment measures for IgG4-AIP has gradually increased. It is of great importance to summarize and discuss the latest progress regarding IgG4-AIP disease., Competing Interests: Declaration of Competing Interest All authors declare no conflicts of interest., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Rationale and Objectives: Magnetic resonance imaging (MRI) has good diagnostic performance and causes no radiation damage, making it an ideal tool for the autoimmune pancreatitis (AIP) surveillance. However, its time cost is high. This study aimed to evaluate (1) whether a simplified protocol (SP) of MRI for AIP surveillance provides information equivalent to the comprehensive protocol (CP) and (2) the time cost reductions associated with using an SP., Materials and Methods: This retrospective single-institutional study included 40 patients with AIP with at least two contrast-enhanced MRI/magnetic resonance cholangiopancreatography studies. Two radiologists evaluated two imaging sets (CP/SP) per patient, independently. Intra- and inter-observer agreement in the evaluation of the pancreas and extrapancreatic organs involvement using the SP/CP in addition to the time cost differences between the SP and CP were assessed. Intra- and inter-rater reliability were assessed using Cohen's kappa test, intraclass correlations, or the weighted kappa test. The differences in time costs between the CP and SP were compared using the Mann-Whitney U test or Wilcoxon signed-rank test., Results: The SP had strong intra- and inter-observer agreement with the CP in evaluating MRI parameters (κ ＞ 0.60, moderate to excellent) and disease activity status (κ ＞ 0.80, all excellent). The overall image acquisition time cost for the SP was 49.2% of the CP. For the two radiologists, the image interpretation time cost of the SP was reduced by approximately 35% and 27% compared to the CP., Conclusion: For AIP surveillance, SP MRI provides information consistent with the CP and is less time-consuming., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: 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., Aims: 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., Methods: 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., Results: 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)., Conclusion: 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., (Copyright © 2024 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Background & Aims: 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., Methods: 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., Results: 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., Conclusions: 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., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objectives: Type 2 is a rare form of autoimmune pancreatitis (AIP). Despite being considered a benign disease, only few studies with limited sample size and short follow-up have been published on type 2 AIP. The aim of this observational study was to evaluate long-term outcomes, such as the risk of relapse, pancreatic insufficiency and cancer in a large type 2 AIP cohort with long follow-up., Methods: Patients with definitive or probable diagnosis of type 2 AIP by International Consensus Diagnostic Criteria (ICDC) present in our prospectively maintained database since 1995 at 31.12.2021 were identified. All patients were clinically evaluated during the year 2022. Clinical, radiological, serological, and pathological data were evaluated., Results: Eighty-eight out of 420 patients present in the database (21%) were diagnosed with type 2 AIP (mean age 33.5 ± 13.5 years). According to the ICDC, 21 patients (23.8%) had a definitive and 67 (76.2%) a probable diagnosis of type 2 AIP. The mean follow-up was 9.2 ± 7.1 years (range 1-27 years). No differences were observed when comparing patients with definitive and probable type 2 AIP diagnosis. Concomitant IBD was reported in 77 patients (87.5%). The probability of disease relapse was lower in patients treated with steroids versus surgery (at 5 years 13% vs. 33%; p = 0.038) but this difference was not statistically significant at multivariable analysis. The risk of endocrine or severe exocrine insufficiency was low (5% and 25%). Four extra-pancreatic malignancies (5%) were diagnosed, none pancreatic. One patient died in a car accident., Conclusions: Type 2 AIP has benign long-term clinical outcomes. Mortality and cancer rates are low and no specific follow-up is needed after radiological remission., (© 2023 The Authors. United European Gastroenterology Journal published by Wiley Periodicals LLC on behalf of United European Gastroenterology.)

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

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

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

Background: 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., Methods: 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., Results: 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)., Conclusions: 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., Competing Interests: Declaration of competing Interest None., (Copyright © 2024 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Background: The risk and prognosis of pancreatobiliary cancer and in patients with autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) remain unclear. Therefore, we retrospectively investigated the risk of pancreatobiliary cancer and prognosis in patients with AIP and IgG4-SC., Methods: Patients with AIP and IgG4-SC at seven centers between 1998 and 2022 were investigated. The following data were evaluated: (1) the number of cancers diagnosed and standardized incidence ratio (SIR) for pancreatobiliary and other cancers during the observational period and (2) prognosis after diagnosis of AIP and IgG4-SC using standardized mortality ratio (SMR)., Results: This study included 201 patients with AIP and IgG4-SC. The mean follow-up period was 5.7 years. Seven cases of pancreatic cancer were diagnosed, and the SIR was 8.11 (95% confidence interval [CI]: 7.29-9.13). Three cases of bile duct cancer were diagnosed, and the SIR was 6.89 (95% CI: 6.20-7.75). The SMR after the diagnosis of AIP and IgG4-SC in cases that developed pancreatobiliary cancer were 4.03 (95% CI: 2.83-6.99)., Conclusions: Patients with autoimmune pancreatitis and IgG4-SC were associated with a high risk of pancreatic and bile duct cancer. Patients with AIP and IgG4-SC have a worse prognosis when they develop pancreatobiliary cancer., (© 2023 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

A 65-year-old man with multiple lymphadenopathies was diagnosed with IgG4-related disease (IgG4-RD) based on findings of a cervical lymph node biopsy and an elevated serum IgG4 level. Treatment was initiated after the onset of autoimmune pancreatitis, and he achieved remission. He developed diffuse large B-cell lymphoma one year later. Pericardial involvement of lymphoma resulted in cardiac tamponade, and he died before histopathological confirmation of lymphoma was made due to a lethal arrhythmia caused by massive involvement of lymphoma into the myocardium. Because patients with IgG4-RD might have an increased risk of malignant diseases, including lymphoma, histopathological examinations should be considered at any time during the course of IgG4-RD.

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., Competing Interests: Conflict-of-interest statement: Authors declare no conflict of interests for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

We are writing in response to the paper published in the World Journal of Gastroenterology by Zhou et al . The authors identified higher serum immunoglobulin (Ig) G4 levels and age over 55 years as independent risk factors for disease relapse. Despite notable strengths, it is crucial to address potential biases. Firstly, the cohort study included 189 patients with autoimmune pancreatitis (AIP) type 1 (with higher IgG4 seropositivity and higher relapse) and 24 with type 2 (with lower IgG4 seropositivity and lower relapse). Consequently, most, if not all, AIP type 2 patients were assigned to the normal group, possibly inflating the association of higher serum IgG4 levels with relapse and potentially exaggerating the association of older age with relapse. Secondly, the authors did not provide sufficient details regarding AIP diagnosis, such as the ratio of definitive vs probable cases and the proportion of biopsies. In cases where histological evidence is unavailable or indeterminate, AIP type 2 may be misdiagnosed as definitive type 1, and type 1 may also be misdiagnosed as probable type 2, particularly in cases with normal or mildly elevated serum IgG4 levels. Lastly, in this retrospective study, approximately one-third of the consecutive patients initially collected were excluded for various reasons. Accordingly, the impact of non-random exclusion on relapse outcomes should be carefully considered. In conclusion, the paper by Zhou et al offers plausible, though not entirely compelling, evidence suggesting a predictive role of elevated serum IgG4 levels and advanced age in AIP relapse. The foundation for future investigations lies in ensuring a reliable diagnosis and accurate disease subtyping, heavily dependent on obtaining histological specimens. In this regard, endoscopic ultrasound-guided fine-needle biopsy emerges as a pivotal component of the diagnostic process, contributing to mitigating biases in future explorations of the disease., Competing Interests: Conflict-of-interest statement: There are no conflicts of interest to report., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Pancreas pathology is constantly evolving and can present various challenges for pathologists. This paper is focused on providing helpful hints for daily routine diagnostics. During histopathological analysis of pancreas biopsies, pancreatic ductal adenocarcinoma must be distinguished not only from other solid neoplasms, but especially from its mimicker, autoimmune pancreatitis. This can be achieved by a systematic workup following clear diagnostic criteria. When analyzing samples from cystic pancreatic lesions, mucin-producing neoplasms must be detected due to their role as pancreatic cancer precursors; molecular analyses can help considerably with their detection and distinction. During frozen section examination, evaluation of the pancreatic neck margin and analysis of unclear lesions of the liver are two important tasks, which are explained further in this article. A special challenge is the evaluation of neoadjuvant treated pancreatic cancer, which requires a detailed macroscopic and microscopic workup. Finally, current advances in precision oncology and emerging approaches for pancreatic cancer within this field are discussed. With the advancement of technical possibilities and their increasingly broad implementation, the classification systems in pancreatic pathology will continue to gain in complexity, but also in accuracy., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

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

Recurrent acute pancreatitis is beginning to be recognized as an intermediary stage in the continuous spectrum between acute and chronic pancreatitis. It is crucial to identify this disease stage and intervene with diagnostic and therapeutic modalities to prevent the painful and irreversible condition of chronic pancreatitis. We review the recent advances in diagnosing and managing this important 'call for action' condition.

Background: The predictive value of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) metabolic parameters for predicting AIP relapse is currently unknown. This study firstly explored the value of 18 F-FDG PET/CT parameters as predictors of type 1 AIP relapse., Methods: This multicenter retrospective cohort study analyzed 51 patients who received 18 F-FDG PET/CT prior to treatment and did not receive maintenance therapy after remission. The study collected baseline characteristics and clinical data and conducted qualitative and semi-quantitative analysis of pancreatic lesions and extrapancreatic organs. The study used three thresholds to select the boundaries of pancreatic lesions to evaluate metabolic parameters, including the maximum standard uptake value (SUV max ), mean standard uptake value (SUV mean ), total lesion glycolysis (TLG), metabolic tumor volume (MTV), and tumor-to-normal liver standard uptake value ratio (SUVR). Univariate and multivariate analyses were performed to identify independent predictors and build a recurrence prediction model. The model was internally validated using the bootstrap method and a nomogram was created for clinical application., Results: In the univariable analysis, the relapsed group showed higher levels of SUV max (6.0 ± 1.6 vs. 5.2 ± 1.1; P = 0.047), SUVR (2.3 [2.0-3.0] vs. 2.0 [1.6-2.4]; P = 0.026), and TLG 2.5 (234.5 ± 149.1 vs. 139.6 ± 102.5; P = 0.020) among the 18 F-FDG PET metabolic parameters compared to the non-relapsed group. In the multivariable analysis, serum IgG 4 (OR, 1.001; 95% CI, 1.000-1.002; P = 0.014) and TLG 2.5 (OR, 1.007; 95% CI, 1.002-1.013; P = 0.012) were independent predictors associated with relapse of type 1 AIP. A receiver-operating characteristic curve of the predictive model with these two predictors demonstrated an area under the curve of 0.806., Conclusion: 18 F-FDG PET/CT metabolic parameters, particularly TLG 2.5 , are potential predictors for relapse in patients with type 1 AIP. A multiparameter model that includes IgG4 and TLG2.5 can enhance the ability to predict AIP relapse., (© 2024. The Author(s).)