Diagnostic criteria for autoimmune chronic pancreatitis revisited

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

Background and Objectives

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

Methods

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

Results

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

Conclusions

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

The Role of Endoscopic Ultrasound and Ancillary Techniques in the Diagnosis of Autoimmune Pancreatitis: A Comprehensive Review

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.

Radiology domain in the diagnosis of IgG4-RD according to the 2019 American College of Rheumatology and European League Against Rheumatism classification

OBJECTIVES

To evaluate the performance of radiology-related inclusion criteria of the 2019 ACR-EULAR classification system in the diagnosis of IgG4-related disease (IgG4-RD).

METHODS

This retrospective single-institution study included patients who received a diagnosis of IgG4-RD between January 2010 and December 2020. Two abdominal radiologists independently reviewed baseline imaging studies and scored radiology findings according to the 2019 ACR-EULAR classification criteria. Additional scores were assigned based on serological, histopathological, and immunostaining features.

RESULTS

Seventy-four patients (58 males and 16 females) with a mean age of 59.3 ± 13.9 years diagnosed with IgG4-RD were included. 51/74 (68.9%) were classified as having IgG4-RD according to the 2019 ACR-EULAR classification criteria. To reach a score ≥ 20 in these 51 patients, the radiology domain was sufficient in 20/51 (39.2%) and adding the serology domain was required for another 20/51 (39.2%). The remaining 11/51 patients (21.6%) required the histopathology and immunostaining domains. Radiological involvement of two or more organs at presentation was significantly associated with a score of ≥ 20 and seen in 43/51 (84.3%) compared to 5/23 (21.7%) of the non-classified group (p < 0.001). The group classified as having IgG4-RD showed a significantly higher proportion of elevated IgG4 levels (39/51, 76.5%) than the non-classified group (8/23, 34.8%) (< 0.001).

CONCLUSION

The study findings support the effectiveness of the radiology-related inclusion criteria of the 2019 ACR-EULAR classification system in diagnosing IgG4-RD. Combining radiology and serology domains achieved the cut-off in 80% of IgG-RD patients, enabling non-invasive diagnosis. The classification of IgG4-RD was significantly associated with multi-organ involvement, particularly affecting the pancreas and biliary system.

CRITICAL RELEVANCE STATEMENT

This study is the first to evaluate the diagnostic performance of the radiology domain in the 2019 ACR-EULAR classification criteria. The study results confirm its utility and potential to enable non-invasive diagnosis when combined with serological testing in a significant proportion of patients.

KEY POINTS

• A significant proportion of patients can be diagnosed with IgG4-RD using the radiology and serology domains exclusively. • Multi-organ involvement is significantly associated with classifying patients as IgG4-RD, with the pancreas and biliary system most frequently affected. • A high level of inter-reader agreement in the scoring of the radiology domain supports its reliability.

Significantly Elevated CA 19-9 after COVID-19 Vaccination and Literature Review of Non-Cancerous Cases with CA 19-9 > 1000 U/mL

BACKGROUND

CA 19-9 is a commonly assessed tumor marker, considered characteristic of pancreatic ductal adenocarcinoma (PDAC) and biliary tract cancers; however, the positive predictive value of CA 19.9 is too low, and the usage of CA 19.9 as a screening tool in the healthy population remains controversial.

METHODS

The presented case illustrates a reversed diagnosis of highly elevated serum CA 19-9 levels in a 54-year-old female complaining of pain in the epigastric region, shortly after COVID-19 vaccination. Laboratory tests showed a significantly elevated level of the CA 19-9 marker (>12,000 U/mL, reference value: <37 U/mL) with normal pancreatic enzyme activity. The patient underwent imaging examination, which showed no abnormalities, except for increased pancreatic dimension and areas of fluid signal in the pancreas in magnetic resonance imaging (MRI), which may correspond to autoimmune pancreatitis (AIP). The patient remains asymptomatic with a recommendation for a follow-up MRI in 12 months.

RESULTS

A literature review conducted revealed multi-causal CA 19-9 increases above 1000 U/mL, including non-cancerous diseases of the lung, pancreas, liver, ovary, kidney, and others. The median concentration of CA 19-9 regardless of the cause of disease was 2810 U/mL (IQR ± 6895). The median CA 19-9 values in men and women were 3500 (IQR ± 10,050) and 2455 (IQR ± 3927), respectively, and differ significantly between the compared groups (p < 0.05). There was no difference between CA 19-9 values and the categorized cause of the increase.

CONCLUSIONS

Conducting differential diagnosis, it should not be forgotten that most international guidelines recommend the use of CA 19-9 only in conjunction with pathology of pancreas in radiological imaging; however, even such a combination can point the diagnostic pathway in the wrong direction. A highly elevated CA 19-9 level, typically associated with PDAC, may be the result of benign disease including AIP related to COVID-19 vaccination.

Thickness of the Hyperechoic Capsule-like Rim Around Pancreatic Lesions Measured by Ultrasound for Differentiating Between Type 1 Autoimmune Pancreatitis and Pancreatic Adenocarcinoma

Background: Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic adenocarcinoma (PAC), resulting in unnecessary surgical interventions. On computed tomography (CT) scans, the capsule-like rim is an essential radiological characteristic for differentiating AIP from PAC. It presents as a hypoattenuating halo surrounding the pancreas. However, this characteristic is infrequently observed in ultrasonography. Objectives: The aim of this study was to assess the accuracy of the thickness measurement of the capsule-like structure surrounding lesions during ultrasonography in order to distinguish between AIP and PAC. Patients and Methods: This case-control study was conducted on 19 patients with type 1 AIP (AIP1) as the case group and 37 patients with PAC as the controls. The ultrasound images of these patients were obtained from our institute's database. The thickest part of the hyperechoic capsule-like structure around lesions was identified and measured on the workstation retrospectively. The difference in the thickness of the capsule-like structure between AIP1 and PAC was compared in all lesions and mass lesions, respectively. The optimal cut-off thickness was determined by the maximum Youden index (calculated as sensitivity + specificity - 1). A P-value of < 0.05 (or < 0.05/3 after applying the Bonferroni correction) was considered statistically significant. Results: All lesions appeared hypoechoic, and there were no significant differences in gender, age, abdominal pain symptoms, jaundice, or weight loss between the case and control groups (P > 0.05). However, there was a significant difference regarding the involved pancreatic location (P = 0.008). Among the lesions, 46 were mass lesions. The hyperechoic capsule-like rim was thicker in the case group compared to the control group for all lesions (mean = 0.40 ± 0.12 vs. 0.32 ± 0.09 cm, P = 0.006) and also for mass lesions (mean = 0.41 ± 0.13 vs. 0.31 ± 0.09 cm, P = 0.006). The cut-off thickness for AIP1 was estimated at 0.41 cm, according to the maximum Youden index in both all lesions and mass lesions. The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and odds ratio for all lesions were 0.58, 0.86, 0.77, 0.69, 0.80, and 8.80 (95% confidence interval [CI]: 2.37 – 32.64), respectively. In mass lesions, the corresponding values were 0.58, 0.88, 0.80, 0.64, 0.86, and 10.50 (95% CI: 2.23 – 49.52), respectively. Conclusion: Patients with a hyperechoic capsule-like rim thickness of ≥0.41 cm during ultrasonography are more likely to have AIP1. This finding holds valuable clinical significance in differentiating between AIP1 and PAC.

Type 1 Autoimmune Pancreatitis Masquerading as Pancreatic Head Carcinoma

Obstructive jaundice is a joint clinical presentation with many etiologies, including pancreatic cancer and autoimmune pancreatitis (AIP). Differentiating between these two conditions is pivotal due to the divergent management approaches and prognoses. In this case report, we present a case of a 49-year-old female patient who presented with weight loss, intermittent chronic abdominal pain, and jaundice. She was initially suspected of having pancreatic cancer because of clinical presentation and imaging findings. However, she was ultimately diagnosed with Type 1 AIP due to histopathology findings and elevated immunoglobulin G4. This case highlights the complexities in diagnosis, the role of advanced imaging techniques and tissue sampling, and the lessons learned regarding managing this challenging clinical scenario.

Diagnostic Utility of Serum IgG4 in Autoimmune Pancreatitis: An Updated Comprehensive Systematic Review and Meta-analysis

OBJECTIVES

Despite many studies suggesting an association between serum immunoglobulin G4 (sIgG4) and autoimmune pancreatitis (AIP), the evidence of utility in differentiation between AIP and pancreatic cancer (PC) remain uncertain.

METHODS

The analysis based on published studies. Data were pooled by means of a random-effects model, and sensitivity, specificity, diagnostic odds ratios (DOR), areas under summary receiver operating characteristic curves were calculated.

RESULTS

In the included thirteen studies, sIgG4 were measured in 594 patients with AIP and 958 patients with PC. The pooled sensitivity, specificity, DOR, and area under the curve were 0.72 [95% confidence interval (CI): 0.68-0.75], 0.93 (95% CI: 0.92-0.95), 51.37 (95% CI: 23.20-113.74), and 0.91 (95% CI: 0.87-0.95). Subgroup analyses of the DORs for region and year: Asia, (112.10; 95% CI: 27.72-453.32), non-Asia (26.01; 95% CI: 12.38-54.65), and year before 2011 (107.61; 95% CI: 39.30-294.68), year after 2011 (26.96; 95% CI: 9.78-74.32). Overall, sIgG4 was associated with AIP, the result revealed a moderate sensitivity 0.72 and high specificity 0.93. In the meta-analysis, the pooled DOR of sIgG4 levels of 2-fold upper limit 50.44 was similar with the DOR 51.37 when 1-fold cut-off value, but the summary receiver operating characteristic was 0.755 and 0.91. The higher specificity (from 93% to 98%) derived from the cut-off value (from 130-140 to 260-280 mg/dL) for sIgG4 occurred at a significant reduction in sensitivity (from 72% to 43%).

CONCLUSIONS

The study revealed sIgG4 is a good marker of AIP. Screening of sIgG4 may help clinicians differentiate between AIP and PC, and the best cut-off value should be 140 rather than 280 mg/dL.

Autoimmune Pancreatitis and Immunoglobulin G4-related Sclerosing Cholangitis: Past, Present, and Future

The emergence of glucocorticoid-responsive autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC), a new disease entity, has attracted considerable interest within the international gastroenterology community. The typical manifestations of AIP/IgG4-SC are obstructive jaundice and pancreatic enlargement in the elderly, which may mimic the presentations of pancreatobiliary malignancies. The timely diagnosis of AIP/IgG4-SC can lead to adequate glucocorticoid treatment, whereas a misdiagnosis can result in unnecessary major surgery. The diagnostic criteria used to diagnose AIP include several cardinal features of AIP that can be detected via pancreatic parenchymal imaging, ductal imaging, serum IgG4 levels, histopathology, other organ involvement, and response to glucocorticoid therapy. The differential diagnosis of AIP/IgG4-SC may include pancreatobiliary malignancies and primary sclerosing cholangitis. Although most patients with AIP/IgG4-SC respond well to glucocorticoid therapy, there is a frequent relapse of the disease in the long term. This review describes the evolution of the concept of AIP and IgG4-related disease, including the development of diagnostic criteria, discusses the current practice for diagnosis and treatment, and suggests prospects for research.

Correlation of Autoimmune Pancreatitis and Malignancy: Systematic Review and Meta-Analysis

BACKGROUND

There is conflicting evidence regarding autoimmune pancreatitis (AIP) association with pancreatic and non-pancreatic cancers. Literature lacks data on overall prevalence of malignancies in autoimmune pancreatitis.

AIM

Given the lack of definite evidence, we aimed to pool and summarize data from available literature regarding prevalence of different malignancies in AIP.

METHODS

We conducted a systematic search of MEDLINE, EMBASE, Cochrane Register of Controlled Trials, and Web of Science through February 16, 2021, to include observational studies assessing the incidence of cancer in AIP. We used the DerSimonian-Laird method with random effects for meta-analysis. Pooled prevalence, 95% confidence interval (CI), and I² statistic are reported.

RESULTS

A total of 17 studies with 2746 patients were included assessing the prevalence of cancer in AIP. The overall prevalence of cancer in AIP was 9.6% [95% confidence interval (CI), 5.7-13.5%]. The cancers with the highest prevalence in AIP population were gastric and colorectal cancer, with prevalence of 1.3% (95% CI, 0.5-2.1%) and 1.2% (95% CI, 0.6-1.8%), respectively.

CONCLUSION

We demonstrate the prevalence of different cancers in AIP. Inflammatory surge in AIP and subsequent carcinogenesis is one explanation for this association. Moreover, AIP can be a paraneoplastic syndrome manifestation of malignancies.

Endoscopic ultrasound-guided pancreatic sampling for the histopathological diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis (AIP), which is characterized by pancreatic enlargement and irregular narrowing of the main pancreatic duct, is difficult to differentiate from malignancy. The irregular narrowing of the pancreatic duct, which can be detected via endoscopic retrograde cholangiopancreatography, is a characteristic feature of AIP; however, distinguishing between localized AIP and pancreatic cancer based on pancreatic duct imaging is difficult. This study overviews the efficacy of endoscopic ultrasound (EUS)-guided pancreatic sampling for the histopathological diagnosis of AIP. Recent enhancements in needle biopsy methodologies and technologies have contributed to improvement in the diagnostic efficacy of this technique. The guidance provided in this study for the histological diagnosis of AIP is anticipated to further advance in the histopathological diagnosis of AIP using EUS-guided pancreatic sampling.

Endoscopic ultrasound-guided fine needle aspiration versus biopsy for diagnosis of autoimmune pancreatitis: Systematic review and comparative meta-analysis

BACKGROUND

Endoscopic ultrasound (EUS) is recommended for guiding the acquisition of pancreatic tissue in patients with suspected autoimmune pancreatitis (AIP). Data comparing EUS-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) sampling in the diagnosis of AIP are limited.

METHODS

A comprehensive literature search of the PubMed, EMBASE, and Ovid MEDLINE databases was conducted until April 2020. The pooled rates of diagnostic yield for the histologic criteria of AIP, histologic tissue procurement, and adverse events were compared between FNA and FNB. Diagnostic yields were also compared between 19 gauge (G) and 22G needles.

RESULTS

This meta-analysis included nine studies comprising 309 patients with AIP who underwent FNA and seven studies comprising 131 patients who underwent FNB. The pooled diagnostic yields for level 1 or 2 histology criteria of AIP were 55.8% (95% confidence interval (CI) 37.0-73.9%, I²  = 91.1) for FNA and 87.2% (95% CI 68.8-98.1%, I²  = 69.4) for FNB (P = 0.030). The pooled histologic procurement rates for FNA and FNB were 91.3% (95% CI, 84.9-97.6%, I²  = 82.9) and 87.0% (95% CI, 77.8-96.1%, I²  = 40.0), respectively (P = 0.501). Adverse events were comparable between two groups. When analyzed by needle size, the diagnostic yield was better with a 19G needle than with a 22G needle (88.9% vs. 60.6%, P = 0.023).

CONCLUSIONS

The diagnostic yield may be better with FNB needles than with FNA needles for the diagnosis of AIP, despite the similar rate of histologic tissue procurement. A quantitative definition for the histologic sample adequacy for AIP may be warranted.

Utilisation of artificial intelligence for the development of an EUS-convolutional neural network model trained to enhance the diagnosis of autoimmune pancreatitis

OBJECTIVE

The diagnosis of autoimmune pancreatitis (AIP) is challenging. Sonographic and cross-sectional imaging findings of AIP closely mimic pancreatic ductal adenocarcinoma (PDAC) and techniques for tissue sampling of AIP are suboptimal. These limitations often result in delayed or failed diagnosis, which negatively impact patient management and outcomes. This study aimed to create an endoscopic ultrasound (EUS)-based convolutional neural network (CNN) model trained to differentiate AIP from PDAC, chronic pancreatitis (CP) and normal pancreas (NP), with sufficient performance to analyse EUS video in real time.

DESIGN

A database of still image and video data obtained from EUS examinations of cases of AIP, PDAC, CP and NP was used to develop a CNN. Occlusion heatmap analysis was used to identify sonographic features the CNN valued when differentiating AIP from PDAC.

RESULTS

From 583 patients (146 AIP, 292 PDAC, 72 CP and 73 NP), a total of 1 174 461 unique EUS images were extracted. For video data, the CNN processed 955 EUS frames per second and was: 99% sensitive, 98% specific for distinguishing AIP from NP; 94% sensitive, 71% specific for distinguishing AIP from CP; 90% sensitive, 93% specific for distinguishing AIP from PDAC; and 90% sensitive, 85% specific for distinguishing AIP from all studied conditions (ie, PDAC, CP and NP).

CONCLUSION

The developed EUS-CNN model accurately differentiated AIP from PDAC and benign pancreatic conditions, thereby offering the capability of earlier and more accurate diagnosis. Use of this model offers the potential for more timely and appropriate patient care and improved outcome.

Autoimmune Pancreatitis after a Seven-Year History of Suspicious Pancreatic Cancer

In this case report, we present a case of autoimmune pancreatitis (AIP) diagnosis in a patient after a 7-year history of suspicious pancreatic cancer. Kim's and Japanese criteria were used to diagnose AIP. Our case avoided undesirable invasive procedures and recovered thanks to the proper diagnosis and timely treatment with prednisone. Early and accurate diagnosis of AIP, in this case, had a significant impact on the treatment and prognosis process.

IgG4-related nephritis and interstitial pulmonary disease complicated by invasive pulmonary fungal infection: a case report

Background

IgG4-related kidney disease (IgG4-RKD) can affect multiple organs, which was first reported as a complication or extra-organ manifestation of autoimmune pancreatitis in 2004. It is characterized by abundant IgG4-positive plasma cells infiltration in tissues involved.

Case presentation

A 69-year-old man presented with cough and renal dysfunction with medical history of hypertension and diabetes. Pathological findings revealed interstitial nephritis and he was initially diagnosed with IgG4-RKD. Prednisone helped the patient to get a remission of cough and an obvious decrease of IgG4 level. However, he developed invasive pulmonary fungal infection while steroid theatment. Anti-fungal therapy was initiated after lung puncture (around cavitary lung lesion). Hemodialysis had been conducted because of renal failure and he got rid of it 2 months later. Methylprednisolone was decreased to 8 mg/day for maintenance therapy. Anti-fungal infection continued for 4 months after discharge home. On the 4th month of follow-up, Chest CT revealed no progression of lung lesions.

Conclusions

The corticosteroids are the first-line therapy of IgG4-RD and a rapid response helps to confirm the diagnosis. This case should inspire clinicians to identify IgG4-related lung disease and secondary pulmonary infection, pay attention to the complications during immunosuppressive therapy for primary disease control.

Diagnostic and therapeutic considerations in biopsy-proven type 2 autoimmune pancreatitis: comparative analysis with biopsy-proven type 1 autoimmune pancreatitis

BACKGROUND

Autoimmune processes are now an increasingly recognized cause of acute and chronic pancreatitis. Autoimmune pancreatitis is a rare, benign pathology with two distinct clinicopathologic subtypes. The aim of this study was to compare the presentation, diagnostic considerations and outcomes of patients with biopsy-proven type 1 and 2 autoimmune pancreatitis (AIP).

METHODS

A retrospective review of the Queensland Health pathology database of histologically proven AIP was conducted. Parameters compared included demographics, diagnostic criterion and post-treatment outcomes.

RESULTS

Twenty-three patients had a confirmed histological diagnosis of AIP (type 1 = 13, type 2 = 10). Patients with type 2 AIP were younger (median age 49 versus 59 years, P < 0.05). There was no significant difference in gender distribution of disease at presentation. Type 2 AIP presented with significant increased focal pancreatic changes on cross-sectional imaging (80% versus 54%, P < 0.05). Serum IgG4 levels were raised (>1.40 g/L) in 69% of patients with type 1 AIP and not detected in type 2 (P < 0.01). Concurrent underlying inflammatory bowel disease was present in a higher proportion of type 2 AIP (40% versus 15%, P < 0.05). A significantly increased proportion of patients with type 2 AIP underwent surgical resection (70% versus 30%, P < 0.05). Conservative management was utilized in more patients with type 1 disease (54% versus 30%). On follow-up, two patients have experienced symptomatic relapse at 6-18 months.

CONCLUSIONS

Diagnostic challenges do exist and clinicians must suspect 2 type AIP in young, serum IgG4-negative inflammatory bowel disease patients with recurrent pancreatitis.

The use of immunohistochemistry for IgG4 in the diagnosis of autoimmune pancreatitis: A systematic review and meta-analysis

BACKGROUND

The diagnosis of autoimmune pancreatitis (AIP) remains challenging, especially when serum IgG4 is normal or imaging features are indeterminate. We performed a systematic review and meta-analysis to evaluate the performance of IgG4 immunostaining of pancreatic, biliary, and ampullary tissues as a diagnostic aid for AIP.

METHODS

A comprehensive literature search of the PubMed, EMBASE, and Ovid MEDLINE databases was conducted until February 2020. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. A random-effects model was used to summarize the diagnostic odds ratio and other measures of accuracy.

RESULTS

The meta-analysis included 20 studies comprising 346 patients with AIP and 590 patients with other pancreatobiliary diseases, including 371 pancreatobiliary malignancies. The summary estimates for tissue IgG4 in discriminating AIP and controls were as follows: diagnostic odds ratio 38.86 (95% confidence interval (CI), 18.70-80.75); sensitivity 0.64 (95% CI, 0.59-0.69); specificity 0.93 (95% CI, 0.91-0.95). The area under the curve was 0.939 for tissue IgG4 in discriminating AIP and controls. Subgroup analysis revealed no significant difference in diagnostic accuracy according to control groups (pancreatobiliary cancer versus other chronic pancreatitis) and sampling site (pancreas versus bile duct/ampulla).

CONCLUSIONS

Current data demonstrate that IgG4 immunostaining of pancreatic, biliary, and ampullary tissue has a high specificity but moderate sensitivity for diagnosing AIP. IgG4 immunostaining may be useful in supporting a diagnosis of AIP when AIP is clinically suspected, but a combination of imaging and serology does not provide a conclusive diagnosis.

Autoimmune Pancreatitis and IgG4-Related Disease: The Storiform Discovery to Treatment

Autoimmune pancreatitis (AIP) is an entity that has been recognized since 1961. Prior to the discovery of elevated serum IgG4 as a useful biomarker for its diagnosis, Dr. Yoshida in 1995 first described the entity of AIP, which in retrospect closely resembles the current concept of type 1 AIP. Since the discovery of IgG4 as a biomarker (the IgG4-era), a novel concept of IgG4-related disease (IgG4-RD) has been accepted as being comprised of two subtypes of AIP: type 1 defined as the pancreatic manifestation of IgG4-RD, and type 2 characterized by granulocytic epithelial lesions. The characteristic features of type 1 AIP are increased serum IgG4 levels, lymphoplasmacytic sclerosing pancreatitis (abundant infiltration of IgG4+ plasmocytes and lymphocytes, storiform fibrosis, and obliterative phlebitis), extrapancreatic manifestations of IgG4-RD (e.g., sclerosing cholangitis, sclerosing sialadenitis, retroperitoneal fibrosis), and steroid responsiveness. These entities can be differentiated from mimickers by a combination of serum IgG4 level, imaging features, and histopathological findings. The current first-line therapy is corticosteroids, or rituximab in high-risk patients with steroid intolerance. Although relapse rates are high, treatment of relapsed disease remains experimental.

Pancreatic endosonographic findings and clinical correlation in Crohn's disease

OBJECTIVES

We aimed to evaluate the incidence of pancreatic alterations in Crohn's disease using endoscopic ultrasound (EUS) and to correlate the number of alterations with current clinical data.

METHODS

Patients diagnosed with Crohn's disease (n=51) were examined using EUS, and 11 variables were analyzed. A control group consisted of patients with no history of pancreatic disease or Crohn's disease. Patients presenting with three or more alterations underwent magnetic resonance imaging (MRI). Pancreatic function was determined using a fecal elastase assay.

RESULTS

Two of the 51 patients (3.9%) presented with four EUS alterations, 3 (5.9%) presented with three, 11 (21.5%) presented with two, and 13 (25.5%) presented with one; in the control group, only 16% presented with one EUS alteration (p<0.001). Parenchymal abnormalities accounted for 39 of the EUS findings, and ductal abnormalities accounted for 11. Pancreatic lesions were not detected by MRI. Low fecal elastase levels were observed in 4 patients, none of whom presented with significant pancreatic alterations after undergoing EUS. Ileal involvement was predictive of the number of EUS alterations.

CONCLUSION

A higher incidence of pancreatic abnormalities was found in patients with Crohn's disease than in individuals in the control group. The majority of these abnormalities are related to parenchymal alterations. In this group of patients, future studies should be conducted to determine whether such morphological abnormalities could evolve to induce exocrine or endocrine pancreatic insufficiency and, if so, identify the risk factors and determine which patients should undergo EUS.

Autoantibody detection is not recommended for chronic pancreatitis: a cross-sectional Study of 557 patients

BACKGROUND

Autoimmune factor was regarded as one of the risk factors in the pathogenesis of chronic pancreatitis (CP), especially for autoimmune pancreatitis (AIP). However, whether autoimmune factor plays a role in non-AIP CP or not was unknown.

METHODS

Hospitalized patients with non-AIP CP from January 2010 to October 2016 were detected for 22 autoantibodies at the time of hospital admission. Autoantibodies with frequency > 0.5% were enrolled to calculate the frequency in historial healthy controls through literature search in PubMed. Differentially expressed autoantibodies were determined between patients and historial healthy controls, and related factors were identified by multivariate logistic regression analysis.

RESULTS

In a total of 557 patients, 113 cases were detected with 19 kinds of positive autoantibodies, among them anti-β2-glycoprotein I (β2-GPI) antibody was most frequent (9.16%). Compared with historial healthy controls, the frequencies of serum β2-GPI and anti SS-B antibody in patients were significantly higher, while frequencies of anti-smooth muscle antibody and anticardiolipin antibody were significantly lower (all P < 0.05). Multivariate logistic regression analysis result showed that diabetes mellitus (OR = 2.515) and common bile duct stricture (OR = 2.844) were the risk factors of positive β2-GPI antibody in patients while diabetes mellitus in first-/second-/third-degree relatives (OR = 0.266) was the protective factor. There were no related factors for other three differentially expressed autoantibodies.

CONCLUSIONS

Four autoantibodies were expressed differentially between patients with non-AIP CP and historial healthy controls. Due to limited significance for diagnosis and treatment of chronic pancreatitis, autoantibodies detection is not recommended conventionally unless suspected of AIP.

Does IgG4 level at the time of diagnosis correlate with disease outcome in IgG4-Related disease?

BACKGROUND/OBJECTIVES

Serum IgG4 level is used as a diagnostic criterion for immunoglobulin G4-related disease (IgG4-RD) but whether it predicts disease progression is unclear. Aim of the study was to investigate if serum IgG4 level at the time of diagnosis correlates with disease outcome.

METHODS

Patients with a definitive diagnosis of IgG4-RD were included in this study. They were divided into two groups - Group 1: Elevated serum IgG4 at diagnosis and Group 2: Normal serum IgG4 at diagnosis. Outcome parameters including multiple organ involvement, exocrine and endocrine dysfunction, relapse and mortality were compared. Data was subanalysed for outcomes on 2 levels of serum IgG4 cut-off - A: The upper limit of normal (ULN) and B: Twice the ULN.

RESULTS

Of 47 patients, 31 (66%) patients had elevated serum IgG4 at diagnosis. There was no statistically significant difference between the two groups in any of the outcome parameters. Data analysed with the serum IgG4 levels > ULN showed no difference between the 2 groups for any of the outcome parameters. However, when the serum IgG4 cut-off was set to twice the ULN, there was a significantly higher rate of disease relapse (42.9% vs 11.5%, p = 0.02) and pancreatic exocrine insufficiency (PEI) (76.2% vs 42.3%, p = 0.041).

CONCLUSION

Raised serum IgG4 greater than two times the ULN was significantly associated with disease relapse and PEI in patients with IgG4-RD. Larger multicentre studies with longer follow-up are required to corroborate these findings and define the role and cut-off value of serum IgG4 in outcomes of IgG4-RD.

The role of EUS-guided fine needle aspiration in autoimmune pancreatitis: a single center prospective study

OBJECTIVES

Histopathological examination is pivotal in diagnosing autoimmune pancreatitis (AIP). The usefulness of EUS-guided fine needle aspiration (EUS-FNA) in diagnosing AIP remains controversial worldwide. The authors conducted this study to evaluate the efficacy of EUS-FNA for AIP diagnosis using a 22-gauge needle.

METHODS

Between January 2013 and May 2017, 37 patients had imaging studies suggestive of AIP at Tongji Hospital, and 27 patients of them were enrolled in this study. Tissue specimens acquired through EUS-FNA were analyzed for periductal lymphoplasmacytic infiltrate (LPI), storiform fibrosis (SF), obliterative phlebitis (OP) and immunoglobulin G4 (IgG4)-positive plasma cell counts. Clinical Trials.gov no: TJ-C20121220.

RESULTS

LPI and SF were present in 18 (66.67%) and 18 (66.67%) of 27 patients, respectively. Abundant IgG4-positive plasmacyte infiltration >10/high-power field (HPF) was detected in 8 of 27 patients (29.63%). OP and the characteristic findings of idiopathic duct-centric chronic pancreatitis (IDCP) and granulocytic epithelial lesion (GEL) were not detected in this study. According to the International Consensus Diagnostic Criteria (ICDC) for AIP, 5 and 12 of 27 patients were assessed as having level 1 and level 2 histological findings, respectively, suggesting that 17 of 27 patients (62.96%) had lymphoplasmacytic sclerosing pancreatitis (LPSP) based on the ICDC.

CONCLUSIONS

In 92.6% of patients, pancreatic tissues with >5 HPFs were obtained by EUS-FNA using a 22-G needle. In 63% of patients, histology was evaluated to be ≥ level 2 according to the ICDC. The study indicates that EUS-FNA with a 22-G needle is valuable in the histopathological diagnosis of AIP.

Diagnosis, treatment and long-term outcome of autoimmune pancreatitis in Sweden

INTRODUCTION

Autoimmune pancreatitis (AIP) is a pancreatic inflammatory process characterized by a strong inflammatory cell infiltration and two histopathologically distinct subtypes: type 1 and type 2. Diagnosis is often challenging and requires a combination of clinical, laboratory and imaging data. AIP can mimic pancreatic tumours leading to unnecessary resections if not correctly diagnosed. Short- and long-term outcomes of AIP have been poorly investigated so far and no large series have been previously reported from Sweden.

METHODS

A single-centre, retrospective, cohort study of patients with histologically confirmed or highly probable diagnosis of AIP according to ICDC criteria. Demographic, clinical and radiological characteristics, type of treatment and its outcomes were collected and analysed.

RESULTS

Seventy-one patients with AIP (87% with type 1), were evaluated at Karolinska University Hospital between 2004 and 2018; 49% males, mean age 49 years (range 44-53). Among them, 28% were histologically confirmed, 35% presented with jaundice, 22% with acute pancreatitis, 39% had non-specific symptoms such as weight loss or abdominal pain, 84% showed other organ involvement (OOI). Radiologically, 76% showed a focal pancreatic enlargement, 27% diffuse enlargement, 27% signs of acute pancreatitis and 10% of chronic pancreatitis. Overall, 58 patients (81%) underwent treatment with different medications: 46 (79%) cortisone, 7 (12%) azathioprine, 5 (8%) other immunosuppressive drugs. Twenty-six (36%) underwent biliary stenting and 12 (16%) were given surgery. In total, 47% of patients developed pancreatic exocrine insufficiency (PEI), of whom 76% had a severe form (faecal elastase-1 < 100 μg/g) and 21% of patients developed diabetes mellitus (pancreatic endocrine insufficiency), of whom 73% required insulin.

CONCLUSIONS

AIP is a challenging disease for diagnosis and treatment. Cortisone treatment is generally successful and provides clinical remission in the large majority of patients (>90%). In the further course of the disease, a considerable number of patients develop PEI and diabetes. Only one-quarter of patients exhibit on imaging the characteristic "sausage-like" pancreas (diffuse enlargement), approximately three-quarters had a focal mass that could be misdiagnosed as pancreatic malignancy.

Management of Autoimmune Pancreatitis

Type 1 autoimmune pancreatitis (AIP) is an IgG-4-related systemic disease that can manifest as a pancreatic disorder or another disorder of presumed autoimmune origin. Type 2 disease is typically characterized by absent IgG-4-positive cells. As patients often present with acute pancreatitis, obstructive jaundice, or pancreatic mass, it is imperative to exclude malignancy, a more common diagnosis. AIP may respond to corticosteroids, and has a strong association with other immune-mediated diseases. Recent literature suggests the benefit of immune-modulating therapy, including rituximab, although no consensus exists. This review covers the essentials of diagnosis, but focuses primarily on management of AIP.

Chronic pancreatitis. Some important historical aspects

Since ancient times the increase of size and hardness sometimes presented by the abdominal structure known as the pancreas has attracted attention. Portal was the first to describe the clinical signs of chronic pancreatitis in 1803. In 1815, Fleischman speculated about the potential role of excessive alcohol consumption. Comfort coined the term "chronic relapsing pancreatitis" in 1946 and described hereditary pancreatitis 6 years later. Zuidema defined tropical pancreatitis in 1959 and 2 years later Sarles described another form of pancreatitis to which Yoshida gave the name autoimmune pancreatitis in 1995. Groove pancreatitis was described by Potet in 1970. Obstructive pancreatitis was defined in 1984 and Ammann identified idiopathic pancreatitis 3 years later. This article gives a historical account of the pioneers who developed the knowledge of how to assess the characteristics that allowed the different forms of chronic pancreatitis to be defined.

Prevalence of inflammatory bowel disease in alcoholic, non-alcoholic and autoimmune pancreatitis

OBJECTIVES

Patients with inflammatory bowel disease (IBD) frequently reveal features of pancreatic inflammation. However, the prevalence of IBD in patients with alcoholic pancreatitis (AP) and nonalcoholic pancreatitis (NAP) has not yet been determined, and the prevalence of IBD in patients with autoimmune pancreatitis (AiP) from Germany is unknown.

AIMS

Thus, we aimed, first, to determine the prevalence of IBD in AP, NAP, and AiP from a tertiary center in Germany and, second, to characterize patients with AiP and IBD.

METHODS

We performed a retrospective cross-sectional study to determine the prevalence of IBD in patients with different forms of pancreatitis presenting to our clinic.

RESULTS

Compared to the general population and to a control group with viral hepatitis from our clinic, we observed the most significant increase of IBD in patients with AiP (n = 3/28; p < 0.0001 vs. general population, binomial proportion test; p = 0.0112 vs. hepatitis group, Fisher's exact test), followed by a significant increase in subjects with NAP (n = 11/278; p < 0.0001 vs. general population, binomial proportion test; p = 0.0338 vs. hepatitis group, Fisher's exact test). A review of previous studies on the prevalence of IBD among patients with AiP revealed a combined prevalence of 12 % (n = 43/355). Type 2 AiP is significantly more often associated with IBD than type 1 AiP (n = 28/48, 58 % vs. n = 7/129, 5 %; combined patient cohort, p < 10E - 12; Fisher's exact test).

CONCLUSIONS

Immune-mediated mechanisms related to IBD may participate in the development of AiP, especially AiP type 2, and may also increase the risk for the development of other forms of pancreatic inflammation.

Localized autoimmune pancreatitis mimicking pancreatic cancer: Case report and literature review

Autoimmune pancreatitis (AP) is a rare autoimmune pancreatic manifestation of systemic immunoglobulin G4 (IgG4)-related sclerosing disease. Distinguishing between AP and pancreatic cancer is crucial because the clinical courses, treatments, and prognoses of these two disease entities are quite different. We herein report a case involving a 52-year-old man with subacute epigastralgia who visited our hospital for evaluation of a suspicious pancreatic mass found during esophagogastroduodenoscopy. Enhanced computed tomography (CT) revealed an enlarged lesion in the pancreatic head with encasement of hepatic vessels. The lesion also exhibited increased ¹⁸F-fluorodeoxyglucose accumulation on positron emission tomography/CT imaging, which was highly suggestive of pancreatic cancer. After open biopsy, morphologic examination showed an inflammatory infiltrate in the pancreas, which was compatible with chronic sclerotic pancreatitis. Further laboratory tests revealed an elevated serum IgG4 level, and the diagnosis of sclerotic pancreatitis was then confirmed. After corticosteroid treatment, the pancreatic lesion showed shrinkage on follow-up CT, and the serum IgG4 titer decreased to the normal range. This case suggests that clinicians should be familiar with the clinical presentations and diagnostic criteria of AP versus pancreatic cancer. An awareness of the differences between these diseases may avoid misdiagnosis and unnecessary surgical intervention.

Monitoring and predicting disease activity in autoimmune pancreatitis with the M-ANNHEIM-AiP-Activity-Score

BACKGROUND & OBJECTIVES

Autoimmune pancreatitis (AiP) is treated by immunosuppressive therapy. Exact description of disease activity of AiP is essential in clinical practice and research, but a score to describe the disease activity is missing. Thus, we aimed to establish an activity score of AiP.

METHODS

We retrospectively studied long-term disease courses of 29 patients with AiP (Mannheim, Germany), receiving corticosteroid treatment (CST) by analyzing 613 treatment appointments. Two assumptions were made: First, disease activity is higher at emergency treatments; second, disease activity drops under CST. In all patients, we evaluated established activity- and classification-systems of chronic pancreatitis (cP). Based on the most suitable system, we established an activity score of AiP by including AiP-specific parameters identified from our long-term disease courses and the literature. The new AiP-specific activity score was validated in an external cohort of 14 patients with AiP (Stockholm, Sweden).

RESULTS

Within published activity indexes of cP, the M-ANNHEIM-classification most significantly correlated with emergency- and treatment-dependent disease activities (p < 0.001 and p < 0.01, conditional-logistic-regression-analysis). Significant correlations of disease activity were found for several clinical parameters (biliary involvement, extrapancreatic lesions, acute pancreatitis, focal pancreatic mass, pancreatic sausage/mass, focal enlargement, ascites; p < 0.05, Wilcoxon-signed-rank-test). Based on these data and disease features from the literature, the M-ANNHEIM-AiP-Activity-Score (MAAS) was established. CST-induced reduction of MAAS disease activity of more than 60% was associated with lower relapse rates (p < 0.05; Chi-Square-test). The results were validated in the external patient cohort.

CONCLUSION

The MAAS might represent a useful tool to monitor AiP.

Prevalence and Incidence of Autoimmune Pancreatitis in the Population Living in the Southwest of Germany

BACKGROUND/AIMS

The prevalence and incidence of autoimmune pancreatitis (AiP) in those living in western countries are largely unknown. We aimed to determine the prevalence of AiP among patients with pancreatitis presenting to our tertiary referral center in Mannheim, Germany; and to estimate the incidence of AiP in the Southwest of Germany.

METHODS

We performed a retrospective cross-sectional analysis and determined the prevalence of AiP in patients with acute pancreatitis (AP) or chronic pancreatitis (CP). Patients (n = 704; alcoholic pancreatitis n = 373, nonalcoholic pancreatitis n = 331) were stratified into the Retrospective-Pancreas-Cohort (RPC, period 1998-2008, n = 534) and the Pancreas-Clinic-Cohort (PCC, periods 2008-2010 and 2013-2014, n = 170, with detailed investigation for features of AiP). Diagnosis of AiP was established by International-Consensus-Diagnostic-Criteria and Unifying-Autoimmune-Pancreatitis-Criteria.

RESULTS

In the RPC, the prevalence of AiP was 5.9% (n = 13/221) among individuals with nonalcoholic pancreatitis (n = 1/61 with AP, 1.6%; n = 12/160 with CP, 7.5%). In the PCC, the prevalence of AiP was 9.1% (n = 10/110) among patients with nonalcoholic pancreatitis (n = 2/24 with AP, 8.3%; n = 8/86 with CP, 9.3%), and 1.7% (n = 1/60) among subjects with alcoholic pancreatitis. We estimated the incidence of AiP with 0.29 per 100,000 population each year.

CONCLUSION

The prevalence rate of AiP may account for 9% of patients with nonalcoholic pancreatitis but is almost never observed in patients with alcoholic pancreatitis. The incidence of AiP in Germany appears lower than 1 per 100,000 population.

The Etiologic Evaluation of Acute Pancreatitis in a General Hospital of Seoul-Gyeonggi Province in Korea

Background/Aims

In recent years, the incidence of acute pancreatitis (AP) has been increasing. A better understanding of the etiology is directly linked to more favorable outcomes. Unfortunately, there have been reports suggesting the variation of etiologies of AP across countries. The objective of this study was to determine the etiology of AP in a general hospital of Seoul-Gyeonggi province in Korea during the past decade.

Methods

We retrospectively reviewed the medical records of consecutive patients with AP who were admitted to St. Paul's Hospital (Seoul, Korea) with an affiliation to the Catholic University of Korea between January 2003 and January 2013.

Results

A total of 1,110 patients were enrolled, totaling 1,833 attacks, and the most frequent cause of AP was alcohol consumption. The recurrence rate of AP was 24.5% (272/1,110), and habitual recurrence rate (more than three times) was 12.6% (140/1,110). The rate of severe AP was 4.9% (90/1,833 attacks). The mortality rate of AP was 2.6% (29/1,110 patients). The frequency of an idiopathic cause of AP was 13.3%. The recurrence rate and mortality rate of idiopathic AP were 16.2% and 5.4%, respectively. In 41.7% (10/24) of cases of idiopathic AP, microlithiasis was suspected.

Conclusions

Between 2003 and 2013 in Korea, alcohol was the most frequent cause of AP in the general hospital of Seoul-Gyeonggi province of Korea. It appears that alcohol abstinence program may be necessary. Further nationwide studies would be needed to evaluate the etiologies of AP.

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.

Diagnosing autoimmune pancreatitis with the Unifying-Autoimmune-Pancreatitis-Criteria

BACKGROUND/OBJECTIVES

We had developed the Unifying-Autoimmune-Pancreatitis-Criteria (U-AIP) to diagnose autoimmune pancreatitis (AiP) within the M-ANNHEIM classification of chronic pancreatitis. In 2011, International-Consensus-Diagnostic-Criteria (ICDC) to diagnose AiP have been published. We had applied the U-AIP long before the ICDC were available. The aims of the study were, first, to describe patients with AiP diagnosed by the U-AIP; second, to compare diagnostic accuracies of the U-AIP and other diagnostic systems; third, to evaluate the clinical applicability of the U-AIP.

METHODS

From 1998 until 2008, we identified patients with AiP using U-AIP, Japanese-, Korean-, Asian-, Mayo-HISORt-, Revised-Mayo-HISORt- and Italian-criteria. We retrospectively verified the diagnosis by ICDC and Revised-Japanese-2011-criteria, compared diagnostic accuracies of all systems and evaluated all criteria in consecutive patients with pancreatitis (2009 until 2010, Pancreas-Outpatient-Clinic-Cohort, n = 84). We retrospectively validated our diagnostic approach in consecutive patients with a pancreatic lesion requiring surgery (Surgical-Cohort, n = 98).

RESULTS

Overall, we identified 21 patients with AiP. Unifying-Autoimmune-Pancreatitis-Criteria and ICDC presented the highest diagnostic accuracies (each 98.8%), highest Youden indices (each 0.95238), and highest proportions of diagnosed patients (each n = 20/21, U-AIP/ICDC vs. other diagnostic systems, p < 0.05, McNemar test). In the Pancreas-Outpatient-Clinic-Cohort, seven patients were diagnosed with AiP (n = 6 by U-AIP, n = 1 by Asian-criteria). International-Consensus-Diagnostic-Criteria confirmed the diagnosis in these individuals. Based on partial fulfillment of U-AIP, AiP was initially suspected in 13% (n = 10/77) of remaining patients from the Pancreas-Outpatient-Clinic-Cohort. In the Surgical-cohort, we identified one patient with AiP by U-AIP and ICDC.

CONCLUSIONS

Unifying-Autoimmune-Pancreatitis-Criteria revealed a satisfactory clinical applicability and offered an additional approach to diagnose AiP.

IgG4-Related disease simulating paraneoplastic syndrome: Role of 18FDG PET/CT imaging

Immunoglobulin G4 (IgG4)-related systemic disease (IgG4-RSD) is a new systemic entity associated with autoimmune pancreatitis (AIP). Other organ involvements take the form of sclerosing cholangitis, sclerosing cholecystitis, sclerosing sialadenitis, retroperitoneal fibrosis, and interstitial nephritis. Recently, lung diseases related to IgG4 have been described to occur with or without other organ involvement. These diseases include interstitial lung disease (ILD), pulmonary inflammatory pseudotumor, and lymphomatoid granulomatosis. Most of these cases occur in combination with AIP, which also appears to have a general preponderance for males. The true incidence of IgG4-related ILD and the incidence of AIP are unknown. Here, we describe a case of a 53-year-old gentleman who presented with weight loss, fever, loose motions, altered sensorium, and persistent low hemoglobin, for which he was referred for 18-fluorodeoxyglucose positron emission tomography/computed tomography scan to diagnose probable underlying occult malignancy/paraneoplastic syndrome. It revealed features suggestive of IgG4 disease involving the pancreas and lungs, which was confirmed subsequently.

[Autoimmune pancreatitis: An update]

CLINICAL/METHODICAL ISSUE

Autoimmune pancreatitis (AIP) is a rare disease, the pathophysiological understanding of which has been greatly improved over the last years. The most common form, type 1 AIP belongs to the IgG4-related diseases and must be distinguished from type 2 AIP, which is a much rarer entity associated with chronic inflammatory bowel disease. Clinically, there is an overlap with pancreatic cancer. Imaging and further criteria, such as serological and histological parameters are utilized for a differentiation between both entities in order to select the appropriate therapy and to avoid the small but ultimately unnecessary number of pancreatectomies.

PERFORMANCE

The diagnostics of AIP are complex, whereby the consensus criteria of the International Association of Pancreatology have become accepted as the parameters for discrimination. These encompass five cardinal criteria and one therapeutic criterion. By applying these criteria AIP can be diagnosed with a sensitivity of 84.9%, a specificity of 100% and an accuracy of 93.8%.

ACHIEVEMENTS

The diagnosis of AIP is accomplished by applying several parameters of which two relate to imaging. As for the routine diagnostics of the pancreas these are ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). Important for the differential diagnosis is the exclusion of signs of local and remote tumor spread for which CT and MRI are established. The essential diagnostic parameter of histology necessitates sufficient sample material, which cannot usually be acquired by a fine needle biopsy. CT or MRI are the reference standard methods for identification of the optimal puncture site and imaging-assisted (TruCut) biopsy.

PRACTICAL RECOMMENDATIONS

In patients presenting with unspecific upper abdominal pain, painless jaundice combined with the suspicion of a pancreatic malignancy in imaging but a mismatch of secondary signs of malignancy, AIP should also be considered as a differential diagnosis. As the diagnosis of AIP only partially relies on imaging radiologists also have to be aware of the clinical, serological and histological parameters for AIP in order to guide clinicians towards the correct diagnosis. Only in this way can the highly efficient steroid therapy be initiated and otherwise possibly severe forms of therapy be avoided.

Diagnosis of autoimmune pancreatitis by EUS-guided FNA using a 22-gauge needle: a prospective multicenter study

BACKGROUND AND AIMS

Histopathologic examination is critical for diagnosing autoimmune pancreatitis (AIP). However, specimens obtained using EUS-guided FNA (EUS-FNA) are not recommended for histopathologic diagnosis because of inadequate sample size volume. We evaluated EUS-FNA efficacy for AIP diagnosis using a 22G needle.

METHODS

Seventy-eight patients exhibiting the imaging characteristics indicative of AIP in the pancreatic parenchyma and pancreatic duct underwent EUS-FNA with a 22G needle at 12 institutions between February 2013 and March 2014. Samples were evaluated for tissue sampling conditions, CD38- and IgG4-positive plasma cell counts, storiform fibrosis (SF), and obliterative phlebitis (OP).

RESULTS

Tissue specimens containing >10, 5 to 10, and 1 to 4 high-power fields (HPFs) were obtained from 29 (37.2%), 18 (23.1%), and 15 (19.2%) of 78 patients, respectively. The mean ± standard deviation (SD) CD38- and IgG4-positive plasma cell counts were 23.2 ± 18.8/HPF and 5.1 ± 6.7/HPF, respectively. SF was detected in 49 of 78 patients (62.8%) and OP in 38 of 78 patients (48.7%). According to the International Consensus Diagnostic Criteria (ICDC), histopathologic levels corresponded to level 1 in 32, level 2 in 13, and unclassifiable in 17 patients. Hence, 45 of 78 patients (57.7%) could be diagnosed with lymphoplasmacytic sclerosing pancreatitis according to ICDC.

CONCLUSIONS

Pancreatic tissues with at least 1 HPF were obtained by EUS-FNA from approximately 80% of patients, and nearly 60% of patients were diagnosed with ICDC level 2 or higher. Our findings indicate that EUS-FNA with a 22G needle may be useful for the histopathologic diagnosis of AIP. (Clinical trial registration number: UMIN000010097.).

The management of autoimmunity in patients with cholestatic liver diseases

Cholestatic liver diseases are rare diseases that often lead to cirrhosis and its consequent complications. In addition to liver-related morbidity, patients with cholestatic liver diseases often suffer from autoimmune diseases that affect several organs and tissues. The robust and efficient data collection and collaboration between hepatologists and rheumatologists have led to significant advancements in understanding the relationship between the cholestatic liver diseases and associated autoimmune diseases. In this paper, we discuss the cholestatic liver diseases (primary biliary cirrhosis, primary sclerosing cholangitis and immunoglobulin G4 associated cholangitis) and associated autoimmune diseases.

Autoimmune Pancreatitis: An Update on Diagnosis and Management

There is an evolving understanding that autoimmune pancreatitis (AIP) is an immunoglobulin (Ig) G4 systemic disease. It can manifest as primarily a pancreatic disorder or in association with other disorders of presumed autoimmune cause. Classic clinical characteristics include obstructive jaundice, abdominal pain, and acute pancreatitis. Thus, AIP can be difficult to distinguish from pancreatic malignancy. However, AIP may respond to therapy with corticosteroids, and has a strong association with other immune mediated diseases. Although primarily a pathologic diagnosis, attempts have been made to reliably diagnose AIP clinically. AIP can be classified as either type 1 or type 2.

Mass-forming type 1 autoimmune pancreatitis mimicking pancreatic cancer

We reported three cases of mass-forming type 1 autoimmune pancreatitis (AIP) that were preoperatively suspected to be pancreatic cancer, and reviewed their clinicopathological features. Radiological findings in the patients revealed hypoattenuating masses in the early phase or a stricture of the main pancreatic duct with upstream dilatation, which was consistent with the diagnosis of pancreatic cancer. Histopathologically, the lesions were well demarcated and met all diagnostic criteria for immunoglobulin G4 (IgG4)-related AIP, including the presence of periductal lymphoplasmacytic infiltration, obliterative phlebitis, storiform fibrosis and abundant IgG4-positive plasma cells. However, the adjacent uninvolved pancreatic duct and lobular structures were well preserved. And in all patients, none or some of the aforementioned characteristics were observed. We suggest that some cases of focal AIP may progress to more severe grades and exhibit mass formation, although remaining localized. These focal cases of AIP are difficult to distinguish from pancreatic cancer. To our knowledge, this report is the first to present a histopathological comparison of mass-forming AIP with the adjacent uninvolved pancreatic tissues.

Diagnosis, treatment and long-term outcomes of autoimmune pancreatitis in Spain based on the International Consensus Diagnostic Criteria: A multi-centre study

OBJECTIVES

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that has been reported worldwide for the last two decades. The aim of this study is to analyse the clinical profile of patients from Spain with AIP, as well as treatments, relapses and long-term outcomes.

METHODS

Data from 59 patients with suspected AIP that had been diagnosed in 15 institutions are retrospectively analysed. Subjects are classified according to the International Consensus Diagnostic Criteria (ICDC). Patients with type 1 AIP (AIP1) and type 2 AIP (AIP2) are compared. Kaplan-Meier methodology is used to estimate the overall survival without relapses.

RESULTS

Fifty-two patients met ICDC, 45 patients were AIP1 (86.5%). Common manifestations included abdominal pain (65.4%) and obstructive jaundice (51.9%). Diffuse enlargement of pancreas was present in 51.0%; other organ involvement was present in 61.5%. Serum IgG4 increased in 76.7% of AIP1 patients vs. 20.0% in AIP2 (p = 0.028). Tissue specimens were obtained in 76.9%. Initial successful treatment with steroids or surgery was achieved in 79.8% and 17.3%, respectively. Maintenance treatment was given in 59.6%. Relapses were present in 40.4% of AIP1, with a median of 483 days. Successful long-term remission was achieved in 86.4%.

CONCLUSIONS

AIP1 is the most frequent form of AIP in Spain in our dataset. Regularly, ICDC allows AIP diagnosis without the need for surgery. Steroid and chirurgic treatments were effective and safe in most patients with AIP, although maintenance was required many times because of their tendency to relapse. Long-term serious consequences were uncommon.

Localized Autoimmune Pancreatitis: Report of a Case Clinically Mimicking Pancreatic Cancer and a Literature Review

Autoimmune pancreatitis (AIP) is a rare disease with clinical presentations that greatly mimic pancreatic cancer (PC). It is critical for clinicians to distinguish AIP from PC because their treatments and prognoses are entirely different. Typical images show characteristic features such as diffuse pancreatic swelling and strictures of the main pancreatic duct (MPD). However, AIP may present as a localized pancreatic mass, in which case it is very difficult to differentiate from PC. Here, we report a case of a 40-year-old man with computed tomography (CT) imaging studies confirming an area of low-density neoplasm in the uncinate process of the pancreas with dilation in the common biliary duct (CBD) and MPD. Increased uptake in the uncinate mass was observed by positron emission tomography (PET)/CT scan, which strongly suggested PC. Further laboratory analyses showed a marked elevation of serum IgG4. Because there was not enough evidence to rule out a diagnosis of malignancy, a histopathological biopsy became the criterion standard. An endoscopic ultrasound (EUS)-guided needle biopsy failed. As an alternative, a pancreaticoduodenectomy was conducted for the biopsy, and pathological analysis confirmed IgG4-related sclerotic chronic pancreatitis with moderate lymphoplasmacellular infiltration.We suggest that an accurate preoperative diagnosis for localized AIP with MPD and CBD obstructions mimicking PC is of great importance. Radiological imaging findings, particularly observations of diffused enlargement of the pancreas and delayed enhancement during the venous and portal phases, are essential for diagnosing AIP. Careful consideration should be given if serum IgG4 was taken as a special indicator for a differential diagnosis between AIP and PC. A history of IgG4-related diseases involving the biliary, lacrimal, salivary, retroperitoneal, renal, or pulmonary systems should also be highlighted. Thus, the pathology of extrapancreatic organs can be utilized as diagnostic evidence when the pathology for a pancreatic mass is not available, as in the case presented here. Furthermore, cautious use of hormone therapy is indicated for patients who cannot be ruled out as having PC. The results of future studies on localized AIP are eagerly awaited.

Laparoscopic and Percutaneous Core Needle Biopsy Plays a Central Role for the Diagnosis of Autoimmune Pancreatitis in a Single-Center Study From Denmark

OBJECTIVES

The aims of this study were to describe the diagnosis of autoimmune pancreatitis (AIP) in Denmark and to test the usefulness of the International Consensus Diagnostic Criteria (ICDC) on a geographically well-defined cohort.

METHODS

All patients diagnosed with AIP at Odense University Hospital from 2007 to 2013 were included (n = 30; mean follow-up, 26.2 months). Data from laparoscopic or percutaneous ultrasound-guided core needle biopsy (CNB), resection specimens, endoscopic ultrasound (EUS), EUS-guided CNB, computed tomography, serum immunoglobulin G4 (IgG4), and pancreatography were retrospectively analyzed according to ICDC.

RESULTS

Twenty patients were diagnosed with type 1, 8 with type 2, and 2 with not otherwise specified AIP. Twenty-eight patients (93%) could correctly be classified when ICDC were retrospectively applied. Serum IgG4 was elevated in 44% of type 1 and 0% of type 2. Other organ involvement was observed in 40% of type 1 and 13% of type 2, but inflammatory bowel disease only in type 2 (P = 0.001). One patient had IgG4-related chronic perisplenitis as a hitherto undescribed manifestation of IgG4-related disease. Nineteen (91%) of 21 biopsied patients had diagnostic CNB features of AIP. Computed tomography, EUS, and pancreatography showed features highly suggestive or supportive of AIP in 68%, 72%, and 71%, respectively.

CONCLUSIONS

Laparoscopic or percutaneous ultrasound-guided CNB had the highest sensitivity for AIP. The ICDC could retrospectively correctly diagnose 93% of the patients.

Diagnosis and Treatment of Autoimmune Pancreatitis in China: A Systematic Review

AIMS

To provide comprehensive data on the diagnosis and treatment of autoimmune pancreatitis (AIP) patients in China.

DESIGN

A systematic review.

METHODS

All clinical studies concerning AIP from China published between January 2006 and June 2014 were retrospectively reviewed and analyzed.

RESULTS

A total of 26 original articles involving 706 AIP patients were included with an estimated proportion of type 2 AIP as 4.7%. In the 706 AIP patients, the range of mean/median age was 48.6-67.0 years old and the male to female ratio was 4.47:1. The common presentations included obstructive jaundice (pooled rate: 63.4%, 95%CI: 55.4%-71.0%) and abdominal symptoms (pooled rate: 62.3%, 95%CI: 52.4%-71.7%). Biliary involvement was the most common extrapancreatic manifestations, especially the lower part of the common bile duct (pooled rate: 62.3%, 95%CI: 49.9%-73.9%). According to the imaging examinations, 53.8% and 41.6% patients were classified into focal-type and diffuse-type, respectively. Notably, upstream pancreatic duct dilatation was found in parts of patients (pooled rate: 13.8%, 95%CI: 6.6%-23.1%). The levels of serum IgG4 were elevated in most patients (pooled rate: 86.0%, 95%CI: 74.2%-94.6%). Nearly three tenths AIP patients received surgery (pooled rate: 29.7%, 95%CI: 18.1%-42.8%) due to mimicked malignancy. Steroid treatment was given to 78.4% patients (95%CI: 65.3%-89.1%) with a pooled remission rate of 96.2% (95%CI: 94.0%-97.9%). The pooled relapse rate was 13.8% (95%CI: 7.2%-22.0%) with the mean follow-up time ranging from 12 to 45 months.

CONCLUSION

Type 1 is the predominant type of Chinese AIP patients and the clinical features, diagnostic modalities and therapeutic regimen were similar with those in other countries. Knowledge of AIP should be more widespread to avoid unnecessary surgery.

Comparison of endoscopic retrograde cholangiopancreatography with papillary biopsy and endoscopic ultrasound-guided pancreatic biopsy in the diagnosis of autoimmune pancreatitis

BACKGROUND

International consensus diagnostic criteria (ICDC) have been proposed for the diagnostic criteria and algorithm of autoimmune pancreatitis (AIP). Although endoscopy is important in the diagnosis of AIP, practical patterns of its usage vary considerably worldwide. This study aimed to compare endoscopic retrograde cholangiopancreatography (ERCP) with papillary biopsy and endoscopic ultrasound (EUS)-guided pancreatic biopsy for diagnosing AIP using ICDC.

METHODS

We retrospectively reviewed and classified 165 Korean patients diagnosed by Korean criteria from June 2007 to October 2013. Among them, 61 patients underwent ERCP with duodenal papillary biopsy (group A) and 62 patients underwent EUS-guided pancreatic biopsy (group B). We analyzed the diagnostic criteria and levels of each criterion, and type of AIP before and after endoscopic procedures.

RESULTS

ERCP with papillary biopsy increased the diagnostic sensitivity from 65.6% (40/61) to 95.1% (58/61) (P < 0.01). EUS-guided pancreatic biopsy increased the diagnostic sensitivity from 50.0% (27/62) to 88.7% (55/62) (P < 0.01). The increases of diagnostic sensitivity in two endoscopic methods were not different statistically. In diagnosing definite AIP, EUS-guided pancreatic biopsy was more useful than ERCP with papilla biopsy (sensitivity; 79.0% vs. 65.6%, P < 0.01). EUS-guided pancreatic biopsy was helpful to classify type 1 and type 2 AIP in some patients. Procedure-related complication (mild pancreatitis) developed in one patient (1.6%) in group A and two patients (3.2%) in group B. ERCP with papillary biopsy was less expensive than EUS-guided pancreatic biopsy.

CONCLUSIONS

Both ERCP with papillary biopsy and EUS-guided pancreatic biopsy are safe and play important roles in diagnosing AIP according to the ICDC.

Irregular narrowing of the main pancreatic duct in association with a wall thickening is a key sign at endoscopic ultrasonography for the diagnosis of autoimmune pancreatitis

OBJECTIVES

The aim of this study was to assess the accuracy of key signs identified at endoscopic ultrasonography in diagnosing an autoimmune pancreatitis (AIP).

METHODS

Between January 2007 and December 2011, a retrospective case-control study was conducted in 177 patients with AIP (n = 30), pancreatic adenocarcinoma (n = 42), pancreatic neuroendocrine tumor (n = 21), alcoholic chronic pancreatitis (n = 32), and symptomatic common bile duct stones (n = 52).

RESULTS

An irregular narrowing of the main pancreatic duct in association with a wall thickening was seen in 28 of 30 AIP, 1 of 42 pancreatic adenocarcinoma, 0 of 21 pancreatic neuroendocrine tumor, 0 of 32 alcoholic chronic pancreatitis, and 0 of 52 common bile duct stones (P < 0.05). Sensitivity, specificity, positive and negative predictive values, and overall diagnostic accuracy of this sign for the diagnosis of AIP were 93%, 99.3%, 96.3%, 98.6%, and 98.3%, respectively. In type 1 AIP, hyperechoic parietal thickening was more frequent (92.3% vs 33.3%, P < 0.05). In type 2 AIP, hypoechoic parietal thickening was more frequent (83.3% vs 23.1%, P < 0.05).

CONCLUSIONS

An irregular narrowing of the main pancreatic duct in association with a wall thickening seen at endoscopic ultrasonography is accurate in diagnosing AIP. The type of echogenicity of the thickening is well correlated with the type of AIP.