Autoimmune Pancreatitis Patients Research Articles

A prospective study on the histological evaluation of type 1 autoimmune pancreatitis using endoscopic ultrasound-guided fine needle biopsy with a 19-gauge Franseen needle.

To assess the diagnostic efficacy and safety of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a 19-gauge Franseen needle for autoimmune pancreatitis (AIP). Twenty patients suspected of having type 1 AIP were prospectively enrolled and underwent EUS-FNB with a 19-gauge Franseen needle. Their data were compared with those of historical controls: a total of 29 type 1 AIP patients had EUS-FNB with a 22-gauge Franseen needle. Specimens suitable for histological evaluation were obtained from 19 of the 20 patients (95%), and the median total tissue area was 11.9 mm2. The histological diagnosis rate of AIP was 65% (95% CI: 43.2%-82%). Adverse events were observed in three patients (15%), and a switch to 22-gauge needles occurred during transduodenal puncture in two patients. Compared to those punctured with 22-gauge needles, patients punctured with 19-gauge needles had greater prevalence of each characteristic feature of lymphoplasmacytic sclerosing pancreatitis, but the difference was not statistically significant. EUS-FNB using a 19-gauge Franseen needle demonstrated favorable performance for the histological diagnosis of AIP and allowed for large tissue samples, potentially facilitating pathological diagnosis. However, during transduodenal puncture, maneuverability is reduced; therefore, the needle may need to be selected according to the puncture site.

Maintenance steroid therapy is associated with decreased risk of malignancy and better prognosis of patients with autoimmune pancreatitis: A multicenter cohort study in Japan

Background/objectivesThe 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. MethodsWe 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. ResultsThe 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. ConclusionsPatients 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.

Main Diagnostic Criteria Usually Does Not Work for Autoimmune Pancreatitis Wrongly Presuming Malignancy

Background. Autoimmune pancreatitis (AIP) usually responds dramatically to steroid therapy. Occasionally, however, misdiagnosed patients have undergone pancreaticoduodenectomy. This study is aimed at providing useful information to improve the accuracy of diagnosis before surgery and thus avoid unnecessary resections in patients with AIP. Methods. From January 2015 to February 2020, a series of patients were enrolled, having undergone pancreaticoduodenectomy for presumed malignancy. AIP diagnoses were confirmed by postoperative pathology. The demographic and clinical data of the AIP patients were evaluated. The main diagnostic criteria (HISORt, Asian, and ICDC) for AIP were applied to assess whether and how unnecessary surgery could have been avoided. Results. A total of 124 cases of pancreaticoduodenectomy were performed for presumed malignancy. Six patients were diagnosed with benign disease and five with AIP. The prevalences of benign disease and AIP were 4.8% and 4%, respectively. Four patients were female and 1 male, with a mean age of 60.0 years old. Jaundice, pain, and weight loss were observed in 100%, 20%, and 40% of AIP patients, respectively. The radiologic features of the AIP patients were a diffusely enlarged gland (40.0%), a focally enlarged gland (40.0%), pancreatic ductal dilatation (60.0%), upstream parenchymal atrophy (20.0%), bile duct thickening (66.0%), and bile duct stricture (40.0%). Based on the diagnostic criteria for AIP, surgery could have been avoided in two cases. Conclusions. IgG4 measurement and integrated use of major diagnostic criteria should be emphasized in every patient eligible for pancreaticoduodenectomies.

Clinical characteristics and outcome of autoimmune pancreatitis based on serum immunoglobulin G4 level: A single-center, retrospective cohort study.

Autoimmune pancreatitis (AIP) has been linked with elevated immunoglobulin (Ig) G4 levels. The characteristics and outcomes of AIP based on serum markers have not been fully evaluated. To compare clinical features, treatment efficacy, and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse. A total of 213 patients with AIP were consecutively reviewed in our hospital from 2006 to 2021. According to the serum IgG4 level, all patients were divided into two groups, the abnormal group (n = 148) with a high level of IgG4 [> 2 × upper limit of normal (ULN)] and the normal group (n = 65). The t-test or Mann-Whitney U test was used to compare continuous variables. Categorical parameters were compared by the χ2 test or Fisher's exact test. Kaplan-Meier curves and log-rank tests were established to assess the cumulative relapse rates. Univariate and multivariate analyses were used to investigate potential risk factors of AIP relapse. Compared with the normal group, the abnormal group had a higher average male age (60.3 ± 10.4 vs 56.5 ± 12.9 years, P = 0.047); higher level of serum total protein (72.5 ± 7.9 g/L vs 67.2 ± 7.5 g/L, P < 0.001), IgG4 (1420.5 ± 1110.9 mg/dL vs 252.7 ± 106.6 mg/dL, P < 0.001), and IgE (635.6 ± 958.1 IU/mL vs 231.7 ± 352.5 IU/mL, P = 0.002); and a lower level of serum complement C3 (100.6 ± 36.2 mg/dL vs 119.0 ± 45.7 mg/dL, P = 0.050). In addition, a lower number of cases with abnormal pancreatic duct and pancreatic atrophy (23.6% vs 37.9%, P = 0.045; 1.6% vs 8.6%, P = 0.020, respectively) and a higher rate of relapse (17.6% vs 6.2%, P = 0.030) were seen in the abnormal group. Multivariate analyses revealed that serum IgG4 [(> 2 × ULN), hazard ratio (HR): 3.583; 95% confidence interval (CI): 1.218-10.545; P = 0.020] and IgA (> 1 × ULN; HR: 5.908; 95%CI: 1.199-29.120; P = 0.029) and age > 55 years (HR: 2.383; 95%CI: 1.056-5.378; P = 0.036) were independent risk factors of relapse. AIP patients with high IgG4 levels have clinical features including a more active immune system and higher relapse rate. Several factors, such as IgG4 and IgA, are associated with relapse.

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

Autoimmune pancreatitis (AIP) is a rare and enigmatic immune-mediated inflammatory disease. We aimed to investigate the prevalence, characteristics, and associated factors of AIP-inflammatory bowel disease (IBD) in China. A retrospective bidirectional case-control study was performed. The diagnoses of IBD and AIP were made based on the European Crohn's and Colitis Organization guidelines and the International Consensus Diagnostic Criteria. IBD controls were matched by age, sex, and IBD type at a ratio of 1:4, while AIP controls were matched by AIP types. The age-standardized prevalence of AIP-IBD patients in the IBD and AIP population were 292.0 and 8151.93 per 100 000 population, respectively. IBD patients had a higher risk of AIP compared to non-IBD patients (odds ratio 8.4, 95% confidence interval 4.7-14.9, P < 0.0001), and AIP patients had a higher risk of developing IBD compared to the general population in China. The mean age at diagnosis of IBD and AIP was 34.83 years and 40.42 years. IBD was diagnosed before AIP in seven cases. The median total IBD and AIP duration was 43.5 months and 13.5 months. Use of mesalamine and tuberculosis were associated with AIP in IBD patients (P = 0.031). And fecal occult blood test was associated with IBD in AIP patients (P = 0.008). Most AIP-IBD patients had ulcerative colitis and type 2 AIP. IBD patients are more likely to develop AIP compared to the general population, and vice versa. Use of mesalamine and tuberculosis infection were associated with AIP, and fecal occult blood test was associated with IBD.

Resolution of a periapical lesion in an autoimmune pancreatitis patient treated with long-term low-dose glucocorticoids: a case report

BackgroundPatients diagnosed with an autoimmune disease are often systemically medicated with glucocorticoids. Autoimmune pancreatitis (AIP) Type 1 is considered a rare autoimmune disease, which is very well responsive to glucocorticoids and hence can be treated optionally on a long-term basis using low dose of the drug. Apical lesions of root canal-treated teeth can be solved by retreatment of the preexisting root canal obturation or via surgical approaches.Case presentationThis case report relates to a 76-year-old male patient, whose symptomatic acute apical periodontitis was treated nonsurgically by root canal treatment. However, overtime both roots of tooth 46 were associated with asymptomatic apical lesions. Despite progression of the lesions, due to a painless situation, the patient refrained from proceeding with any further treatment options after explaining the pathological pathway with all its consequences. A few years later the patient was prescribed 2.5 mg glucocorticoid prednisone daily for long-term therapy due to an AIP Type 1. Six years later under strict glucocorticoid therapy the apical lesions healed nearly completely and the patient remained free of symptoms without any further interventions.ConclusionsThese observations suggest that prospective clinical studies are required to further elucidate the potential healing effect of systemic long-term low-dose glucocorticoid medication on lesions of endodontic origin.

Diabetes mellitus in patients with type 1 autoimmune pancreatitis at diagnosis and after corticosteroid therapy

BackgroundA 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. MethodsPatients 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’). ResultsAmong 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. ConclusionsPatients 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.

A CT based radiomics nomogram for differentiation between focal-type autoimmune pancreatitis and pancreatic ductal adenocarcinoma.

The purpose of this study was to develop and validate an CT-based radiomics nomogram for the preoperative differentiation of focal-type autoimmune pancreatitis from pancreatic ductal adenocarcinoma. 96 patients with focal-type autoimmune pancreatitis and pancreatic ductal adenocarcinoma have been enrolled in the study (32 and 64 cases respectively). All cases have been confirmed by imaging, clinical follow-up and/or pathology. The imaging data were considered as: 70% training cohort and 30% test cohort. Pancreatic lesions have been manually delineated by two radiologists and image segmentation was performed to extract radiomic features from the CT images. Independent-sample T tests and LASSO regression were used for feature selection. The training cohort was classified using a variety of machine learning-based classifiers, and 5-fold cross-validation has been performed. The classification performance was evaluated using the test cohort. Multivariate logistic regression analysis was then used to develop a radiomics nomogram model, containing the CT findings and Rad-Score. Calibration curves have been plotted showing the agreement between the predicted and actual probabilities of the radiomics nomogram model. Different patients have been selected to test and evaluate the model prediction process. Finally, receiver operating characteristic curves and decision curves were plotted, and the radiomics nomogram model was compared with a single model to visually assess its diagnostic ability. A total of 158 radiomics features were extracted from each image. 7 features were selected to construct the radiomics model, then a variety of classifiers were used for classification and multinomial logistic regression (MLR) was selected to be the optimal classifier. Combining CT findings with radiomics model, a prediction model based on CT findings and radiomics was finally obtained. The nomogram model showed a good sensitivity and specificity with AUCs of 0.87 and 0.83 in training and test cohorts, respectively. The areas under the curve and decision curve analysis showed that the radiomics nomogram model may provide better diagnostic performance than the single model and achieve greater clinical net benefits than the CT finding model and radiomics signature model individually. The CT image-based radiomics nomogram model can accurately distinguish between focal-type autoimmune pancreatitis and pancreatic ductal adenocarcinoma patients and provide additional clinical benefits.

Characteristics and outcomes of patients with autoimmune pancreatitis after pancreatectomy: a retrospective study

Objective: Autoimmune pancreatitis (AIP) is a rare and special type of pancreatitis, which is often difficult to distinguish from pancreatic cancer. We aimed to discuss the clinical characteristics, operation characteristics, and therapeutic effects of AIP patients who received surgical treatment based on retrospective analysis. Methods: The medical records of patients who underwent surgery at Peking Union Medical College Hospital from January 2012 to July 2021 and whose postoperative pathology was AIP were collected. Clinical symptoms, laboratory examinations, imaging features, surgical information, and prognostic data were analyzed. Results: Nineteen patients with AIP (median age 60 years old, 14 males) underwent surgery, whose main indication for surgery was suspected of a malignant lesion (n = 18, 94.7%). Ten patients underwent pancreaticoduodenectomy, 8 underwent distal pancreatectomy, and 1 underwent total pancreatectomy, the pathological result of whom were all AIP. The main postoperative complication was pancreatic fistula (n = 11, 57.9%), and one patient (5.3%) underwent a second operation due to gastrointestinal anastomotic bleeding. One patient (5.6%) had a recurrence of AIP, 3 patients (16.7%) were treated with glucocorticoid after surgery, and one patient (5.6%) was treated with immunosuppressors. Conclusions: Differential diagnosis of AIP from pancreatic cancer is complex. Operation difficulty and complication incidence for patients with AIP were similar to pancreatic cancer patients. Although glucocorticoid is the first-line treatment for AIP, surgery may still be necessary for patients who are strongly suspected of a malignant lesion.

Type 2 autoimmune pancreatitis associated with ulcerative colitis.

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

Diagnostic value of imaging examination in autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) is a special type of chronic pancreatitis mediated by autoimmunity factors. It can be divided into two categories according to pathological characteristics: Lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric pancreatitis. In the clinical setting, the imaging manifestations of some AIP cases are atypical, so it is difficult to distinguish it from general pancreatitis, pancreatic ductal adenocarcinoma, lymphoma, and other malignant disorders. Most importantly, the treatment for and prognosis of these diseases are different. Therefore, a timely correct imaging diagnosis of AIP is key for AIP patients. After that, clinicians can take appropriate treatment measures for those patients, which is helpful for the prognosis of AIP.

Exocrine and Endocrine Insufficiency in Autoimmune Pancreatitis: A Matter of Treatment or Time?

Background: Autoimmune pancreatitis (AIP) is a specific form of chronic pancreatitis with a high relapse rate after treatment. AIP patients are burdened with an increased risk of long-term sequelae such as exocrine and endocrine insufficiency. Our objective was to investigate if pharmacological treatment affects both endocrine and exocrine pancreatic function in patients with AIP. Methods: We included 59 patients with definite AIP in the final analysis. Screening for diabetes mellitus (DM) and pancreatic exocrine insufficiency (PEI) was performed at the time of AIP diagnosis and during follow-up. Results: There were 40 (67.8%) males and 19 (32.2%) females; median age at diagnosis was 65 years. Median follow-up after the diagnosis of AIP was 62 months. PEI prevalence at diagnosis was 72.7% and was 63.5% at follow-up. The cumulative incidence of DM was 17.9%, with a prevalence of DM at diagnosis of 32.8%. No strong association was found between pharmacological treatment and occurrence of PEI and DM. Univariate analysis identified potential risk factors for PEI (other organ involvement and biliary stenting) and for DM (overweight, blue-collar profession, smoking, weight loss or obstructive jaundice as presenting symptoms, imaging showing diffuse pancreatic enlargement, smoking). In a multivariate analysis, only obstructive jaundice was identified as a risk factor for DM both at diagnosis and during follow-up. Conclusions: Our results suggest that the prevalence of endocrine and exocrine insufficiency in AIP is high at diagnosis with an additional risk of PEI and DM during follow-up despite pharmacological treatment.

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

Autoimmune pancreatitis (AIP) and inflammatory bowel disease (IBD) are categorized into immune-mediated inflammatory disorders (IMIDs). While AIP is a pancreato-biliary IMID with an increased incidence and prevalence among patients with IBD, its features are still unclear. This systematic review and meta-analysis aims to assess the prevalence and clinical characteristics of AIP-IBD patients. Electronic databases were searched to identify observational studies assessing AIP and IBD. The primary outcome was the prevalence of IBD among AIP patients, and vice versa. Secondary outcomes included clinical findings and outcomes of each IMID in AIP-IBD patients. The pooled rate of each outcome was determined using a random effects model. For primary outcomes, 40 observational studies with 4031 AIP patients were included and the pooled prevalence of IBD was 10.5% (95% CI 7.2-15.0%). Meanwhile, five studies with 10,551 IBD patients were included and the pooled prevalence of AIP was 0.6% (95% CI 0.2-1.9%). For secondary outcomes, 53 observational studies with 469 AIP-IBD patients were assessed. The rates of type 2 AIP and ulcerative colitis were 79.2% (95% CI 69.1-86.6%) and 74.8% (95% CI 68.2-80.4%), respectively. We also demonstrated AIP-IBD patients were at a significant increased risk of AIP recurrence and colectomy compared with patients with either AIP or IBD (RR=1.9, 95% CI 1.1-3.1 and P=0.014 and RR=3.7, 95% CI 1.9-6.9, P<0.001, respectively). Our meta-analysis reported the prevalence of AIP-IBD patients and demonstrated patients with both IMIDs had a high risk of poor outcomes.

Functional IKK/NF-κB signaling in pancreatic stellate cells is essential to prevent autoimmune pancreatitis

Pancreatic stellate cells (PSCs) are resident cells in the exocrine pancreas which contribute to pancreatic fibrogenesis and inflammation. Studies on NF-κB in pancreatitis so far focused mainly on the parenchymal and myeloid compartments. Here we show a protective immunomodulatory function of NF-κB in PSCs. Conditional deletion of NEMO (IKKγ) in PSCs leads to spontaneous pancreatitis with elevated circulating IgM, IgG and antinuclear autoantibodies (ANA) within 18 weeks. When further challenged with caerulein, NEMOΔCol1a2 mice show an exacerbated autoimmune phenotype characterized by increased infiltration of eosinophils, B and T lymphocytes with reduced latency period. Transcriptomic profiling shows that NEMOΔCol1a2 mice display molecular signatures resembling autoimmune pancreatitis patients. Mechanistically, we show that PSCΔNEMO cells produce high levels of CCL24 ex vivo which contributes to eosinophil recruitment, as neutralization with a CCL24 antibody abolishes the transwell migration of eosinophils. Our findings uncover an unexpected immunomodulatory role specifically of NF-κB in PSCs during pancreatitis.

Unraveling the relationship between autoimmune pancreatitis type 2 and inflammatory bowel disease: Results from two centers and systematic review of the literature.

IntroductionThe relationship between autoimmune pancreatitis (AIP) type 2 and inflammatory bowel disease (IBD) has been established and previously described within International Consensus Diagnostic Criteria. However, it is unknown if the presence of IBD changes the natural disease course of AIP type 2. Our aim was to investigate the association between AIP type 2 and IBD as well as to systematically summarize all the existing evidence in the literature.MethodsElectronic medical record analysis was conducted in two centers (in Stockholm, Sweden, and Milan, Italy; records dated between January 2001 and June 2021). Additionally, we conducted a systematic review of the literature.ResultsA total of 35 patients (18 females, 51.4%) fulfilled the diagnostic criteria of AIP type 2 and were included in the study. A diagnosis of IBD was established in 29 patients (82.8%), ulcerative colitis in 17 (58.6%) and Crohn's disease in 11 (37.9%). Median follow‐up was 54 months. AIP patients with IBD commonly presented with abdominal pain and/or acute pancreatitis at diagnosis, the latter was prevailing in concomitant and later IBD onset. These patients more frequently used steroids, but there were no differences in relapse rates. Concomitant onset of IBD was associated with the development of diabetes mellitus. There were no cases of colon or pancreatic malignancy during follow‐up. In our systematic analysis, a total of 693 AIP type 2 patients were included from 24 single‐center retrospective studies and 8 multicenter retrospective studies. A diagnosis of IBD was reported in 330 (47.8%) patients. Relapse rate was 20.0%.ConclusionsClinical and radiological remission of AIP type 2 was high, while the cumulative incidence of relapse is around 20%. Our results show that concomitance of IBD imposes no obvious risk of a different disease course for AIP type 2.

HLA-DRB1∗16 and -DQB1∗05 alleles are strongly associated with autoimmune pancreatitis in a cohort of hundred patients

Background/objectivesAutoimmune diseases are often associated with human leukocyte antigen (HLA) haplotypes, indicating that changes in major histocompatibility complex (MHC)-dependent self-peptide or antigen presentation contribute to autoimmunity. In our study, we aimed to investigate HLA alleles in a large European cohort of autoimmune pancreatitis (AIP) patients. MethodsHundred patients with AIP, diagnosed and classified according to the International Consensus Diagnostic Criteria (ICDC), were prospectively enrolled in the study. Forty-four patients with chronic pancreatitis (CP) and 254 healthy subjects served as control groups. DNA was isolated from blood samples and two-digit HLA typing was performed with sequence-specific primer (SSP-) PCR. HLA allele association strength to AIP was calculated as odds ratio. ResultsWe uncovered a strong enrichment of HLA-DQB1 homozygosity in type 1 and type 2 AIP patients. Moreover, a significantly increased incidence of the HLA-DRB1∗16 and HLA-DQB1∗05 alleles and a concomitant lack of the HLA-DRB1∗13 allele was detected in AIP type 1 and type 2 patients. In contrast, the HLA-DQB1∗02 allele was underrepresented in the ‘not otherwise specified’ (NOS) AIP subtype. We detected no significant difference in the HLA-DRB3, HLA-DRB4 and HLA-DRB5 allele frequency in our cohort. ConclusionsAlthough AIP type 1 and type 2 are characterized by distinct histopathological characteristics, both subtypes are associated with the same HLA alleles, indicating that the disease might rely on similar immunogenic mechanisms. However, AIP NOS represented another subclass of AIP.

Persistent enlargement of the pancreatic gland after glucocorticoid therapy increases the risk of relapse in IgG4-related autoimmune pancreatitis.

This study aims to clarify the relationship between the changes of pancreatic size after glucocorticoid (GC) therapy and relapse in IgG4-related autoimmune pancreatitis (AIP). We prospectively enrolled 205 newly diagnosed IgG4-related AIP patients. 145 patients were followed up for more than 3years. These patients were divided into three groups according to the changes of pancreatic size after treatment of 6months: pancreatic swelling, normal size, and pancreatic atrophy. Baseline clinical and laboratory parameters were compared among three groups. Kaplan-Meier survival analysis was performed in the 134 patients based on GC therapy. Besides, Cox regression analysis and logistic regression analysis were performed to identify risk factors associated with relapse and the potential variables affecting changes of pancreatic size after treatment. Age at diagnosis, white blood cell count, and serum IgG1 level at baseline were significantly different among the three groups. After treatment of 6months, the pancreas of most patients (n = 81, 55.9%) could return to normal size, while persistent pancreatic swelling was found in 24.1% patients (n = 35), and atrophy was observed in 20.0% of the patients (n = 29). Kaplan-Meier survival analysis presented patients with pancreatic swelling after 6months of GC therapy were more likely to relapse in the follow-up of 3years. Persistent pancreatic swelling after treatment and salivary gland involvement at baseline were independent risk variables associated with relapse in IgG4-related AIP patients, while GC-based therapy was a protective factor of relapse. Logistic regression analysis revealed that older age at diagnosis was associated with pancreatic atrophy and higher baseline serum IgG1 level was associated with pancreatic swelling after treatment of 6months. Patients with persistent pancreatic swelling after GC-based therapy of 6months were more likely to relapse in the follow-up of 3years. Older age at diagnosis and higher baseline serum IgG1 level were potential variables associated with pancreatic atrophy or swelling after treatment of 6months. Key Points • Patients with persistent pancreatic swelling after glucocorticoid-based therapy were more likely to relapse in IgG4-related autoimmune pancreatitis. • Older age at diagnosis was associated with pancreatic atrophy after glucocorticoid-based therapy. • Higher baseline serum IgG1 level was associated pancreatic swelling after glucocorticoid-based therapy.

The features and clinical outcomes of inflammatory bowel disease associated with autoimmune pancreatitis: A greater awareness is needed.

The prevalence of inflammatory bowel disease (IBD) has been described in 5% to 40% of autoimmune pancreatitis (AIP) patients. The aim of our study was to evaluate the prevalence, endoscopic features, and outcome of IBD in association with AIP.A retrospective analysis including all consecutive patients with AIP and a histological diagnosis of IBD from 2010 to 2020 was performed. Demographical data, AIP, and IBD features, as well as clinical course, were recorded.Among 267 AIP patients, 45 were diagnosed with ulcerative colitis (UC) (27 men, mean age 31.6), all with a diagnosis of type 2 AIP. The most frequent presentation of AIP was acute pancreatitis (55.5%). Both diffuse (51.1%) and focal (48.9%) pancreatic involvement were observed. The AIP relapse rate was 11.1% over a mean follow-up of 55 months. In 69% of patients, the interval time between the diagnosis of AIP and UC was <1 year. When UC was present at AIP onset, UC was in clinical remission in 50% of patients. Fecal calprotectin levels, when available, were elevated in 86.6% of these patients. Mostly, mild–moderate pancolitis was initially diagnosed (55.5%). During follow-up, escalation therapy for UC was required in 40% of patients after a mean time of 45 months. Two patients (4.4%) underwent colectomy.The prevalence of UC in AIP patients was 17%. Mild pancolitis with a low rate of colectomy was found. Greater awareness is needed to avoid a delayed diagnosis of UC, and the dosage of fecal calprotectin levels could have a role in this setting.

P260 Autoimmune pancreatitis in patients with Inflammatory Bowel Disease: results from a multicentre ECCO CONFER cases series

Abstract Background Autoimmune pancreatitis (AIP) is an uncommon inflammatory disorder that may accompany inflammatory bowel disease (IBD). The clinical relevance of AIP-IBD coexistence, therapeutic strategies, and long-term outcomes are scarcely known. Methods In this ECCO COllaborative Network For Exceptionally Rare case reports project (ECCO-CONFER) we included cases of AIP diagnosed in patients with IBD. Data on the diagnostic criteria, clinical characteristics, and patient outcomes were retrospectively collected and analysed. Results The cohort included 82 patients [54% males, 77% with ulcerative colitis (UC), age at IBD and AIP diagnosis 32±16 and 35±16 years, respectively]. Of all AIP patients, 71% were classified as type 2, 21% as type 1, and 8% as undefined type. Detailed characteristics of the study group are shown in Table 1. In 57% of the individuals, IBD was diagnosed before AIP. In the remaining cases, IBD was diagnosed simultaneously (20%) or afterwards (23%). Half of the patients required immunomodulators and 43% biological therapy to control their IBD. Twenty-two percent of UC and 6% of Crohn’s disease (CD) required surgical intervention during a mean follow-up of 3.6±3.4 years. Histological confirmation was used in 38% of cases, while the remaining were diagnosed as probable AIP based on clinical, biochemical, and radiologic criteria. Magnetic resonance was the most frequently used imaging modality (61%). Eighty percent of patients received steroids for AIP. Thiopurines were used for AIP in 16 (19%) patients, 81% of them responded to treatment. One patient was successfully treated for AIP with infliximab. AIP complications occurred in 27%, including pancreatic exocrine insufficiency (19%) and diabetes (13%). Five patients underwent surgery due to suspected pancreatic cancer. Patients with complicated AIP were significantly older at AIP and IBD diagnosis, were more frequently males and presented with weight loss at AIP diagnosis, and had less frequently a family history of IBD (Table 1). Colonic IBD (i.e. UC, isolated colonic IBD-unclassified or colonic CD) was seen in a higher proportion of individuals with complicated vs benign AIP course (91% vs 33%, p&amp;lt;0.0001). At the end of follow-up, 75 (91%) and 73 (89%) patients were in remission of AIP and IBD, respectively. No IBD or AIP-related deaths were reported. Conclusion In this large international cohort of patients with concomitant AIP-IBD, most patients have type 2 AIP and colonic IBD. AIP course is relatively benign, and long-term outcomes are favourable. Older age, male gender, isolated colonic IBD location, and weight loss at AIP presentation were seen in higher proportions of patients with a complicated course of AIP.

Autoimmune pancreatitis presenting as obstructive jaundice – A diagnostic challenge

Autoimmune pancreatitis (AIP) is a rare form of pancreatitis which can mimic carcinoma head of the pancreas or distal cholangiocarcinoma, causing the diagnostic dilemma. A 64-year-old postmenopausal woman presented with jaundice, generalized itching, and intermittent low-grade fever for 2 weeks. On evaluation, she had a bulky pancreas on imaging and distal biliary stricture on magnetic resonance cholangiopancreatography. She was planned for Whipple's resection, but her serum immunoglobulin G4 (IgG4) was very high. She was started on oral high-dose steroids considering the possibility of AIP and had significant improvement after 2 weeks of treatment. AIP can mimic distal cholangiocarcinoma and can cause a diagnostic challenge in patients admitted with obstructive jaundice. The presence of high serum IgG4 level and treatment response to steroids help in making the diagnosis. This case reminds the readers to consider AIP in patients with obstructive jaundice who have imaging findings of distal cholangiocarcinoma to avoid unnecessary operations on patients without cancer.