Autoimmune pancreatitis:Cornerstones and future perspectives

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.

Can serum immunoglobulin G4 levels and age serve as reliable predictors of relapse in autoimmune pancreatitis?

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 nonrandom 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.

Unmet needs in biomarkers for autoimmune pancreatitis diagnosis

Autoimmune pancreatitis(AIP)is a rare chronic autoimmune disorder.The diagnosis of AIP mainly depends on histopathology,imaging and response to treatment.Serum immunoglobulin 4(IgG4)is used only as collateral evidence in diagnostic criteria for AIP because of its moderate sensitivity.Serum IgG4 levels are normal in 15%-37%of type 1 AIP and most of type 2 AIP patients.In these patients,the indeterminate imaging and histopathology may lead to the difficulty in definitive diagnosis of AIP.Therefore,discovery of new biomarkers is impor-tant for AIP diagnosis.Here,we provide some views on the progression and challenges in identifying novel serological biomarkers in AIP diagnosis.

Understanding autoimmune pancreatitis: Clinical features, management challenges, and association with malignancies

In this editorial we comment on the article by Jaber et al.Autoimmune pancreatitis(AIP)represents a distinct form of pancreatitis,categorized into AIP-1 and AIP-2,characterized by obstructive jaundice,lymphoplasmacytic infiltrate,and fibrosis.AIP-1,associated with elevated immunoglobulin G4(IgG4)levels,exhibits higher relapse rates,affecting older males,while AIP-2 is less common and linked to inflammatory bowel disease.AIP is considered a manifestation of IgG4-related systemic disease,sharing characteristic histological findings.Steroids are the primary treatment,with emerging biomarkers like interferon alpha and inter-leukin-33.AIP poses an increased risk of various malignancies,and the assoc-iation with pancreatic cancer is debated.Surgery is reserved for severe cases,necessitating careful evaluation due to diagnostic challenges.AIP patients may have concurrent PanINs but display favorable long-term outcomes compared to pancreatic cancer patients.Thorough diagnostic assessment,including biopsy and steroid response,is crucial for informed surgical decisions in AIP.

Type one autoimmune pancreatitis based on clinical diagnosis: A case report

BACKGROUND Autoimmune pancreatitis(AIP)is a rare form of autoimmune-mediated pancrea-titis,which is easily misdiagnosed as pancreatic cancer and thus treated surgi-cally.We studied the diagnosis and treatment of a patient with type 1 AIP recent-ly admitted to our hospital,and reviewed the literature to provide a reference for clinical diagnosis of AIP.CASE SUMMARY The chief complaint was yellowing of the body,eyes and urine for 21 d.The pa-tient's clinical presentation was obstructive jaundice and imaging suggested pan-creatic swelling.It was difficult to distinguish between inflammation and tumor.Serum immunoglobulin G4(IgG4)was markedly elevated.IgG4 is an important serological marker for type 1 AIP.The patient was diagnosed with AIP,IgG4-related cholangitis,acute cholecystitis and hepatic impairment.After applying hormonal therapy,the patient's symptoms improved significantly.At the same time,imaging suggested that pancreatic swelling subsided,and liver function and other biochemical indicators decreased.The treatment was effective.CONCLUSION In patients with pancreatic swelling,the possibility of AIP should be considered.

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

BACKGROUND 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.AIM To compare clinical features,treatment efficacy,and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse.METHODS 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 theχ^(2) test or Fisher’s exact test.Kaplan-Meier curves Zhou GZ et al.Clinical characteristics and outcome of AIP WJG https://www.wjgnet.com 5126 September 21,2023 Volume 29 Issue 35 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.RESULTS 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.CONCLUSION 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.

Serum biomarkers for the differentiation of autoimmune pancreatitis from pancreatic ductal adenocarcinoma

Autoimmune pancreatitis(AIP),a chronic inflammation caused by the immune system attacking the pancreas,usually presents imaging and clinical features that overlap with those of pancreatic ductal adenocarcinoma(PDAC).Serum biomarkers,substances that quantitatively change in sera during disease development,are a promising non-invasive tool with high utility for differentiating between these diseases.In this way,the presence of AIP is currently suspected when serum concentrations of immunoglobulin G4(IgG4)antibody are elevated.However,this approach has some drawbacks.Notably,IgG4 antibody concentrations are also elevated in sera from some patients with PDAC.This review focuses on the most recent and relevant serum biomarkers proposed to differentiate between AIP and PDAC,evaluating the usefulness of immunoglobulins,autoantibodies,chemokines,and cytokines.The proposed serum biomarkers have proven useful,although most studies had a small sample size,did not examine their presence in patients with PDAC,or did not test them in humans.In addition,current evidence suggests that a single serum biomarker is unlikely to accurately differentiate these diseases and that a set of biomarkers will be needed to achieve adequate specificity and sensitivity,either alone or in combination with clinical data and/or radiological images.

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

Autoimmune pancreatitis(AIP)is a complex,poorly understood disease gaining increasing attention."Clinical Characteristics and Outcome of AIP Based on Serum IgG4 levels,"investigated AIP with a focus on serum immunoglobulin(Ig)G4 levels.The 213 patients with AIP were classified according to serum IgG4 levels:Abnormal(elevated)and normal.Patients with higher IgG4 levels exhibited a more active immune system and increased relapse rates.Beyond IgG4,the IgA levels and age independently contributed to relapse risk,guiding risk assessment and tailored treatments for better outcomes.However,limitations persist,such as no IgA correlation with IgG4 levels,absent data on autoantibodypositive AIP cases critical for Asian diagnostic criteria,and unexplored relapse rates in high serum IgG AIP by subtype.Genetic factors and family histories were not addressed.As the understanding and referral of seronegative AIPs increase,there's a growing need for commercially available,highly sensitive,and specific autoantibodies to aid in diagnosing individuals with low or absent serum IgG4 levels.

Challenges for clinicians treating autoimmune pancreatitis:Current perspectives

Autoimmune pancreatitis(AIP)is a rare disease clinically characterized by obstructive jaundice,unintentional weight loss,acute pancreatitis,focal pancreatic mass,and diabetes.AIP is classified into two subtypes-type 1 and type 2-according to pathological findings,clinical features,and serology test results,but some cases may be defined as type not otherwise in the absence of pathological findings and inflammatory bowel disease.To address the differences in diagnostic criteria by country,standard diagnostic criteria for AIP were proposed in 2011 by an international consensus of expert opinions.Differential diagnosis of AIP from pancreatic ductal adenocarcinoma is important but remains challenging for clinicians.Fortunately,all subtypes of AIP show dramatic response to steroid treatment.This review discusses the current perspectives on the diagnosis and management of AIP in clinical practice.

Biomarkers in autoimmune pancreatitis and immunoglobulin G4-related disease

Solitary organ autoimmune disorders,formerly known as autoimmune pancreatitis(AIP),autoimmune sialadenitis,and autoimmune sclerosing cholangitis,are now considered organ-specific manifestations of systemic immunoglobulin G4-related disease(IgG4-RD).AIP and IgG4-RD are characterized by elevated serum concentration of IgG4 antibody(Ab),accumulation of IgG4-expressing plasmacytes in the affected organs,and involvement of multiple organs.It is well established that enhanced IgG4 Ab responses are a hallmark of AIP and IgG4-RD for diagnosis and monitoring disease activity.However,a significant fraction of patients with AIP and IgG4-RD who develop chronic fibroinflammatory responses have normal serum concentrations of this IgG subtype.In addition,disease flare-up is sometimes seen even in the presence of normalized serum concentrations of IgG4 Ab after successful induction of remission by prednisolone.Therefore,it is necessary to identify new biomarkers based on the understanding of the pathophysiology of AIP and IgG4-RD.Recently,we found that activation of plasmacytoid dendritic cells producing both interferon-α(IFN-α)and interleukin-33(IL-33)mediate murine AIP and human IgG4-RD.More importantly,we provided evidence that serum concentrations of IFN-αand IL-33 could be useful biomarkers for the diagnosis and monitoring of AIP and IgG4-RD activity after induction of remission in these autoimmune disorders.In this Frontier article,we have summarized and discussed biomarkers of AIP and IgG4-RD,including Igs,autoAbs,and cytokines to provide useful information not only for clinicians but also for researchers.

Autoimmune pancreatitis:report of two cases and literature review

BACKGROUND: Autoimmune pancreatitis (All?) is a unique chronic inflammation of the pancreas in which autoimmune mechanisms are involved in the pathogenesis. It is characterized by clinical, histopathological, radiographic, serologic and therapeutic features. Since it was first described in 1995, increasing numbers of AIP patients have been diagnosed. METHODS: In this study, the data from 2 patients with AIP who had elevation of serum immunoglobulin G, positive autoantibody, swelling of the pancreas and narrowing of the main pancreatic duct on imaging were analyzed retrospectively. RESULTS: With the initial diagnosis of AIP, both patients underwent regular prednisone therapy, which was initiated at a dose of 40 mg per day with a tapering schedule of 5 mg every 2 weeks. The patients responded very well to treatment with prednisone. CONCLUSIONS: AIP is a relatively new disease entity. Although it is diagnosed by distinct characteristics of the clinical, radiologic, histopathologic, and serologic findings, many questions require further clarification, including its relationship to other autoimmune diseases and misdiagnosis as pancreaticobiliary malignancies.

Autoimmune pancreatitis versus pancreaticcancer: a comprehensive review withemphasis on differential diagnosis

BACKGROUND: Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis with a discrete pathophysiology occasional diagnostic radiological findings, and characteristic histological features. Its etiology and pathogenesis are still under investigation, especially during the last decade Another aspect of interest is the attempt to establish specific criteria for the differential diagnosis between autoimmune pancreatitis and pancreatic cancer, entities that are frequently indistinguishable. DATA SOURCES: An extensive search of the PubMed database was performed with emphasis on articles about the differential diagnosis between autoimmune pancreatitis and pancreatic cancer up to the present. RESULTS: The most interesting outcome of recent research is the theory that autoimmune pancreatitis and its various extra-pancreatic manifestations represent a systemic fibro inflammatory process called IgG4-related systemic disease The diagnostic criteria proposed by the Japanese Pancreatic Society, the more expanded HISORt criteria, the new definitions of histological types, and the new guidelines of the International Association of Pancreatology help to establish the diagnosis of the disease types. CONCLUSION: The valuable help of the proposed criteria for the differential diagnosis between autoimmune pancreatitis and pancreatic cancer may lead to avoidance of pointless surgical treatments and increased patient morbidity.

Simultaneous occurrence of autoimmune pancreatitis and pancreatic cancer in patients resected for focal pancreatic mass

AIM To assess the occurrence of autoimmune pancreatitis(AIP) in pancreatic resections performed for focal pancreatic enlargement.METHODS We performed a retrospective analysis of medical records of all patients who underwent pancreatic resection for a focal pancreatic enlargement at our tertiary center from January 2000 to July 2013. The indication for surgery was suspicion of a tumor based on clinical presentation, imaging findings and laboratory evaluations. The diagnosis of AIP was based on histology findings. An experienced pathologist specialized in pancreatic disease reviewed all the cases and confirmed the diagnosis in pancreatic resection specimens suggestive of AIP. The histological diagnosis of AIP was set according to the international consensus diagnostic criteria.RESULTS Two hundred ninety-five pancreatic resections were performed in 201 men and 94 women. AIP was diagnosed in 15 patients(5.1%, 12 men and 3 women) based on histology of the resected specimen. Six of them had AIP type 1, nine were diagnosed with AIP type 2. Pancreatic adenocarcinoma(PC) was also present in six patients with AIP(40%), all six were men. Patients with AIP + PC were significantly older(60.5 vs 49 years of age, P = 0.045), more likely to have been recently diagnosed with diabetes(67% vs 11%, P = 0.09), and had experienced greater weight loss(15.5 kg vs 8.5 kg, P = 0.03) than AIP patients without PC. AIP was not diagnosed in any patients prior to surgery; however, the diagnostic algorithm was not fully completed in every case. CONCLUSION The possible co-occurrence of PC and AIP suggests that preoperative diagnosis of AIP does not rule out simultaneous presence of PC.

Diagnosis and treatment of autoimmune pancreatitis: experience with 100 patients

BACKGROUND： Autoimmune pancreatitis （ALP） is increasingly recognized as a unique subtype of pancreatitis. This study aimed to analyze the diagnosis and treatment of AIP patients from a tertiary care center in China. METHODS： One hundred patients with AIP who had been treated from January 2005 to December 2012 in our hospital were enrolled in this study. We retrospectively reviewed the data of clinical manifestations, laboratory tests, imaging examinations, pathological examinations, treatment and outcomes of the patients. RESULTS： The median age of the patients at onset was 57 years （range 23-82） with a male to female ratio of 8.1：1. The common manifestations of the patients included obstructive jaundice （49 patients, 49.0%）, abdominal pain （30, 30.0%）, and acute pancreatitis （11, 11.0%）. Biliary involvement was one of the most extrapancreatic manifestations （64, 64.0%）. Fifty-six （56.0%） and 43 （43.0%） patients were classified into focal- type and diffuse-type respectively according to the imaging examinations. The levels of serum IgG and IgG4 were elevated in 69.4% （43/62） and 92.0% （69/75） patients. Pathological analysis of specimens from 27 patients supported the diagnosis of lymphoplasmacytic sclerosing pancreatitis, and marked （〉10 ceUs/HPF） IgG4 positive cells were found in 20 （74.1%） patients.Steroid treatment and surgery as the main initial treatments were given to 41 （41.0%） and 28 （28.0%） patients, respectively. The remission rate after the initial treatment was 85.0%. Steroid was given as the treatment after relapse in most of the patients and the total remission rate at the end of follow-up was 96.0%. CONCLUSIONS： Clinical manifestations, laboratory tests, imaging and pathology examinations in combination could increase the diagnostic accuracy of AIP. Steroid treatment with an initial dose of 30 or 40 mg prednisone is effective and safe in most patients with AIP.

Helicobacter pylori infection and other bacteria in pancreatic cancer and autoimmune pancreatitis

Helicobacter pylori(H.pylori)is an infectious agent influencing as much as 50%of the world’s population.It is the causative agent for several diseases,most especially gastric and duodenal peptic ulcer,gastric adenocarcinoma and mucosaassociated lymphoid tissue lymphoma of the stomach.A number of other,extragastric manifestations also are associated with H.pylori infection.These include neurological disorders,such as Alzheimer’s disease,demyelinating multiple sclerosis and Parkinson’s disease.There is also evidence for a relationship between H.pylori infection and such dermatological diseases as psoriasis and rosacea as well as a connection with infection and open-angle glaucoma.Generally little is known about the relationship between H.pylori infection and diseases of the pancreas.Most evidence about H.pylori and its potential role in the development of pancreatic diseases concerns pancreatic adenocarcinoma and autoimmune forms of chronic pancreatitis.There is data(albeit not fully consistent)indicating modestly increased pancreatic cancer risk in H.pylori-positive patients.The pathogenetic mechanism of this increase is not yet fully elucidated,but several theories have been proposed.Reduction of antral Dcells in H.pylori-positive patients causes a suppression of somatostatin secretion that,in turn,stimulates increased secretin secretion.That stimulates pancreatic growth and thus increases the risk of carcinogenesis.Alternatively,H.pylori,as a part of microbiome dysbiosis and the so-called oncobiome,is proven to be associated with pancreatic adenocarcinoma development via the promotion of cellular proliferation.The role of H.pylori in the inflammation characteristic of autoimmune pancreatitis seems to be explained by a mechanism of molecular mimicry among several proteins(mostly enzymes)of H.pylori and pancreatic tissue.Patients with autoimmune pancreatitis often show positivity for antibodies against H.pylori proteins.H.pylori,as a part of microbiome dysbiosis,also is viewed as a potential trigger of autoimmune inflammation of the pancreas.It is precisely these relationships(and associated equivocal conclusions)that constitute a center of attention among pancreatologists,immunologists and pathologists.In order to obtain clear and valid results,more studies on sufficiently large cohorts of patients are needed.The topic is itself sufficiently significant to draw the interest of clinicians and inspire further systematic research.Next-generation sequencing could play an important role in investigating the microbiome as a potential diagnostic and prognostic biomarker for pancreatic cancer.

Clinical analysis of high serum IgE in autoimmune pancreatitis

AIM: To clarify the clinical significance of high serum IgE in autoimmune pancreatitis (AIP). METHODS: Forty-two AIP patients, whose IgE was measured before steroid treatment, were analyzed. To evaluate the relationship between IgE levels and the disease activity of AIP, we examined (1) Frequency of high IgE (> 170 IU/mL) and concomitant allergic dis-eases requiring treatment; (2) Correlations between IgG, IgG4, and IgE; (3) Relationship between the presence of extrapancreatic lesions and IgE; (4) Re-lationship between clinical relapse and IgE in patients treated with steroids, and (5) Transition of IgE before and after steroid treatment. RESULTS: IgE was elevated in 36/42 (86%) patients.Concomitant allergic disease was observed in seven patients (allergic rhinitis in three, bronchial asthma in three, and urticaria in one). There were no signifi-cant correlations between IgG, IgG4, and IgE (r = -0.168 for IgG, and r = -0.188 for IgG4). There was no significant difference in IgE in the patients with and without extrapancreatic lesions (526 ± 531 IU/mL vs 819 ± 768 IU/mL, P = 0.163), with and without clini-cal relapse (457 ± 346 IU/mL vs 784 ± 786 IU/mL, P = 0.374). There was no significant difference in IgE between before and after steroid treatment (723 ± 744 IU/mL vs 673 ± 660 IU/mL, P = 0.633). CONCLUSION: Although IgE does not necessarily reflect the disease activity, IgE might be useful for the diagnosis of AIP in an inactive stage.

Multifocal autoimmune pancreatitis:A retrospective study in a single tertiary center of 26 patients with a 20-year literature review

BACKGROUND Multifocal-type autoimmune pancreatitis(AIP),sometimes forming multiple pancreatic masses,is frequently misdiagnosed as pancreatic malignancy in routine clinical practice.It is critical to know the imaging features of multifocaltype AIP to prevent misdiagnosis and unnecessary surgery.To the best of our knowledge,there have been no studies evaluating the value of diffusionweighted imaging(DWI),axial fat-suppressed T1 weighted image(T1WI),and dynamic contrast enhanced-computed tomography(DCE-CT)in detecting the lesions of multifocal-type AIP.AIM To clarify the exact prevalence and radiological findings of multifocal AIP in our cohorts and compare the sensitivity of DWI,axial fat-suppressed T1WI,and DCECT for detecting AIP lesions.We also compared radiological features between multifocal AIP and pancreatic ductal adenocarcinoma with several key imaging landmarks.METHODS Twenty-six patients with proven multifocal AIP were retrospectively included.Two blinded independent radiologists rated their confidence level in detecting the lesions on a 5-point scale and assessed the diagnostic performance of DWI,axial fat-suppressed T1WI,and DCE-CT.CT and magnetic resonance imaging of multifocal AIP were systematically reviewed for typical imaging findings and compared with the key imaging features of pancreatic ductal adenocarcinoma.RESULTS Among 118 patients with AIP,26(22.0%)had multiple lesions(56 lesions).Ulcerative colitis was associated with multifocal AIP in 7.7%(2/26)of patients,and Crohn’s disease was present in 15.3%(4/26)of patients.In multifocal AIP,multiple lesions,delayed homogeneous enhancement,multifocal strictures of the main pancreatic duct,capsule-like rim,lower apparent diffusion coefficient values,and elevated serum Ig4 level were observed significantly more frequently than pancreatic ductal adenocarcinoma,whereas the presence of capsule-like rim in multifocal-type AIP was lower in frequency than total AIP.Of these lesions of multifocal AIP,DWI detected 89.3%(50/56)and 82.1%(46/56)by the senior and junior radiologist,respectively.CONCLUSION Multifocal AIP is not as rare as previously thought and was seen in 22.0%of our patients.The diagnostic performance of DWI for detecting multifocal AIP was best followed by axial fat-suppressed T1WI and DCE-CT.

Endoscopic ultrasound features of autoimmune pancreatitis: The typical findings and chronic pancreatitis changes

BACKGROUND Few studies have fully described endoscopic ultrasound(EUS)features of newly diagnosed autoimmune pancreatitis(AIP)involving both typical findings and chronic pancreatitis(CP)features.The typical EUS findings are prevalent in the diffuse type AIP but may not be as common for the focal type,and the differences between the diffuse and focal AIP need to be specified.AIM To demonstrate the EUS features of newly diagnosed AIP and the difference between diffuse and focal AIP.METHODS This retrospective single center study included 285 patients of newly diagnosed type 1 AIP following the international consensus diagnostic criteria,with the EUS procedures accomplished before corticosteroid initiation.We explored the EUS features and compared the typical AIP and CP features between the diffuse and focal AIP cases.The Rosemont criteria were employed for CP features definition and CP change level comparison.RESULTS For the typical AIP features,there were significantly more patients in the diffuse group with bile duct wall thickening(158 of 214 cases,73.4%vs 37 of 71 cases,52.1%,P=0.001)and peripancreatic hypoechoic margin(76 of 214 cases,35.5%vs 5 of 71 cases,7.0%,P<0.001).For the CP features,there were significantly more patients in the focal group with main pancreatic duct dilation(30 of 214 cases,14.0%vs 18 of 71 cases,25.3%,P=0.03).The cholangitis-like changes were more prevalent in the focal cases with pancreatic head involvement.The CP change level was relatively limited for newly diagnosed AIP cases in both groups.CONCLUSION This study demonstrated the difference in the typical AIP and CP features between diffuse and focal AIP and indicated the limited CP change level in newly diagnosed AIP.

Autoimmune pancreatitis and pancreatic cancer:Epidemiological aspects and immunological considerations

Ordinary chronic pancreatitis is a well-known risk factor for pancreatic cancer,whereas such an association with autoimmune pancreatitis(AIP)is widely debated.Due to the rarity of the latter disorder,there are few specific clinical and epidemiological studies investigating the relation between AIP and pancreatic cancer,which do not seem to support it.However,these studies are affected by several limitations and,therefore,a link between AIP(and,specifically,type 1 AIP)and pancreatic cancer cannot be ruled out definitively on this basis.Moreover,several immunopathological aspects of type 1 AIP and,in general,immunoglobulin G4-related disease can create an immunological context that may impair the tumoral immunosurveillance and promote the pancreatic carcinogenesis and its progression.In detail,Th2 immunological dominance,type 2 macrophage polarization and basophil infiltration observed in type 1 AIP,may play a permissive role in creating a favorable immunological environment for pancreatic carcinogenesis,in addition to the immunosuppressive therapies that can be used in these patients.

Recent advances in the management of autoimmune pancreatitis in the era of artificial intelligence

Autoimmune pancreatitis(AIP)is a type of immune-mediated pancreatitis subdivided into two subtypes,type 1 and type 2 AIP.Furthermore,type 1 AIP is considered to be the pancreatic manifestation of the immunoglobulin G4(IgG4)-related disease.Nowadays,AIP is increasingly researched and recognized,although its diagnosis represents a challenge for several reasons:False positive ultrasound-guided cytological samples for a neoplastic process,difficult to interpret levels of IgG4,the absence of biological markers to diagnose type 2 AIP,and the challenging clinical identification of atypical forms.Furthermore,60%and 78%of type 1 and type 2 AIP,respectively,are retrospectively diagnosed on surgical specimens of resected pancreas for suspected cancer.As distinguishing AIP from pancreatic ductal adenocarcinoma can be challenging,obtaining a definitive diagnosis can therefore prove difficult,since endoscopic ultrasound fine-needle aspiration or biopsy of the pancreas are suboptimal.This paper focuses on recent innovations in the management of AIP with regard to the use of artificial intelligence,new serum markers,and new therapeutic approaches,while it also outlines the current management recommendations.A better knowledge of AIP can reduce the recourse to surgery and avoid its overuse,although such an approach requires close collaboration between gastroenterologists,surgeons and radiologists.Better knowledge on AIP and IgG4-related disease remains necessary to diagnose and manage patients.