Usefulness of endoscopic observation of the main duodenal papilla in the diagnosis of sclerosing pancreatitis

Increased ERCP-related adverse event from premature urgent ERCP following symptom onset in acute biliary pancreatitis with cholangitis

Acute biliary pancreatitis (ABP) with cholangitis requires endoscopic retrograde cholangiopancreatography (ERCP) within 24 h to resolve ductal obstruction. However, this recommendation is based on the timing of emergency room (ER) visits. We wanted to determine the optimal timing of ERCP for ABP based on the timing of symptom onset, not the timing of the ER visit. We retrospectively reviewed 162 patients with ABP with cholangitis who underwent urgent ERCP (within 24 h of ER admission). Area under the receiver operating characteristic (ROC) curve (AUC) was analyzed to determine differences in complication rates according to time from symptom onset. A difference in ERCP-related adverse events (AEs) was identified, and Youden's J statistic was used to determine a cutoff time from symptom onset (18 h). We compared mortality and complications based on this cutoff. Based on time to symptom onset, significantly higher rates of aspiration pneumonia (odds ratio [OR] 4.00, 95% confidence interval [CI] 1.15-13.92, P = 0.021) and post-ERCP hypotension (OR 11.9, 95% CI 1.39-101.33, P = 0.005) were observed in the ≤ 18-h group than in the > 18-h group. The study found that patients who underwent ERCP within 18 h of symptom onset is associated with an increased risk of ERCP-related AEs.

Current status of type 1 (IgG4-related) autoimmune pancreatitis

In 1995, Yoshida et al. proposed first the concept of "autoimmune pancreatitis" (AIP). Since then, AIP has been accepted as a new pancreatic inflammatory disease and is now divided two subtypes. Type 1 AIP affected immunoglobulin G4 (IgG4) and implicates the pancreatic manifestation of IgG4-related disease, while type 2 is characterized by neutrophil infiltration and granulocytic epithelial lesions (GEL). Recent research has clarified the clinical and pathophysiological aspects of type 1 AIP, which is more than type 2 among the Japanese population. However, many details remain unclear about the pathogenesis and progression of this disease. In this review, we discuss the current knowledge and recent advances relating to type 1 AIP.

Diagnostic imaging guide for autoimmune pancreatitis

The International Consensus Diagnosis Criteria for autoimmune pancreatitis (AIP) has been published internationally for the diagnosis of AIP. However, since the revisions in 2006 and 2011, the Clinical Diagnostic Criteria for Autoimmune Pancreatitis 2018 have been published. The criteria were revised based the Clinical Diagnostic Criteria 2011, and included descriptions of characteristic imaging findings such as (1) pancreatic enlargement and (2) distinctive narrowing of the main pancreatic duct. In addition, pancreatic duct images obtained by magnetic resonance cholangiopancreatography as well as conventional endoscopic retrograde pancreatography were newly adopted. The guideline explains some characteristic imaging findings, but does not contain descriptions of the imaging methods, such as detailed imaging parameters and optimal timings of dynamic contrast-enhanced computed tomography/magnetic resonance imaging. It is a matter of concern that imaging methods can vary from hospital to hospital. Although other characteristic findings have been reported, these findings were not described in the guideline. The present paper describes the imaging methods for obtaining optimal images and the characteristic imaging findings with the aim of standardizing image quality and improving diagnostic accuracy when radiologists diagnose AIP in actual clinical settings.

Clinical features of isolated proximal-type immunoglobulin G4-related sclerosing cholangitis

BACKGROUND AND AIM

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) presents as isolated proximal-type sclerosing cholangitis (i-SC). The present study sought to clarify the imaging differences between i-SC and Klatskin tumor. Differences between i-SC and IgG4-SC associated with autoimmune pancreatitis (AIP-SC) were also studied.

METHODS

Differentiating factors between i-SC and Klatskin tumor were studied. Serum IgG4 level, CA19-9 level, computed tomography (CT) findings, cholangiography findings (symmetrical smooth long stricture extending into the upper bile duct [SSLS]), endosonographic features (continuous symmetrical mucosal lesion to the hilar part [CSML]), endoscopic biopsy results, treatment, relapse, and survival were also compared between patients with i-SC and those with AIP-SC.

RESULTS

For a differential diagnosis between i-SC (N = 9) and Klatskin tumor (N = 47), the cut-off value of serum IgG4 level was 150 mg/dL (sensitivity, 0.857, specificity, 0.966). Logistic regression analysis indicated that serum IgG4 level, presence of SSLS, presence of CSML, and presence of swollen ampulla are independent factor for identifying i-SC. Relapse rate was significantly higher in the IgG4-SC with AIP group than in the i-SC group (log rank, P = 0.046).

CONCLUSION

Isolated proximal-type sclerosing cholangitis presents as a nodular lesion with SSLS and/or CSML mimicking a Klatskin tumor. Those endoscopic features might provide a diagnostic clue for i-SC. i-SC is likely to have a more favorable prognosis than IgG4-SC with AIP.

Clinical practice guidelines for IgG4-related sclerosing cholangitis

IgG4‐related sclerosing cholangitis (IgG4‐SC) is a distinct type of cholangitis frequently associated with autoimmune pancreatitis and currently recognized as a biliary manifestation of IgG4‐related disease. Although clinical diagnostic criteria of IgG4‐SC were established in 2012, differential diagnosis from primary sclerosing cholangitis and cholangiocarcinoma is sometimes difficult. Furthermore, no practical guidelines for IgG4‐SC are available. Because the evidence level of most articles retrieved through searching the PubMed, Cochrane Library, and Igaku Chuo Zasshi databases was below C based on the systematic review evaluation system of clinical practice guidelines MINDS 2014, we developed consensus guidelines using the modified Delphi approach. Three committees (a guideline creating committee, an expert panelist committee for rating statements according to the modified Delphi method, and an evaluating committee) were organized. Eighteen clinical questions (CQs) with clinical statements were developed regarding diagnosis (14 CQs) and treatment (4 CQs). Recommendation levels for clinical statements were set using the modified Delphi approach. The guidelines explain methods for accurate diagnosis, and safe and appropriate treatment of IgG4‐SC.

Characteristic findings of endoscopic retrograde cholangiopancreatography in autoimmune pancreatitis

Background/Aims

Diffuse or segmental irregular narrowing of the main pancreatic duct (MPD), as observed by endoscopic retrograde cholangiopancreatography (ERCP), is a characteristic feature of autoimmune pancreatitis (AIP).

Methods

ERCP findings were retrospectively examined in 40 patients with AIP in whom irregular narrowing of the MPD was detected near the orifice. The MPD opening sign was defined as the MPD within 1.5 cm from the orifice being maintained. The distal common bile duct (CBD) sign was defined as the distal CBD within 1.5 cm from the orifice being maintained. Endoscopic findings of a swollen major papilla and histological findings of specimens obtained from the major papilla were examined in 26 and 21 patients, respectively.

Results

The MPD opening sign was detected in 26 of the 40 patients (65%). The distal CBD sign was detected in 25 of the 32 patients (78%), which showed stenosis of the lower bile duct. The patients who showed the MPD opening sign frequently showed the distal CBD sign (p=0.018). Lymphoplasmacytic infiltration, but not dense fibrosis, was histologically detected in biopsy specimens obtained from the major papilla.

Conclusions

On ERCP, the MPD and CBD adjacent to the major papilla are frequently maintained in patients with AIP involving the pancreatic head. These signs are useful for diagnosing AIP on ERCP.

[Autoimmune pancreatitis]

Autoimmune pancreatitis is a benign fibroinflammatory disease of the pancreas of probable autoimmune origin, which includes 2 different phenotypes: type 1 (lymphoplasmacytic sclerosing pancreatitis) and type 2 (idiopathic duct-centric pancreatitis). Its clinical presentation as obstructive jaundice in patients with a pancreatic mass is common and therefore it must be included in the differential diagnosis of pancreatic neoplasia. Many diagnostic criteria have been described throughout history. The most famous are the HISORT criteria of the Mayo Clinic and the international consensus criteria of 2011. One of the main features of autoimmune pancreatitis is its dramatic response to steroid therapy, without the need for surgical treatment. Knowledge of this disease can dramatically change the management of patients with obstructive jaundice, who would otherwise be subjected to a pancreaticoduodenectomy.

Major and minor duodenal papillae in autoimmune pancreatitis

OBJECTIVE

The objective of this study was to evaluate picture of the major and minor duodenal papillae in patients with autoimmune pancreatitis (AIP).

METHODS

Endoscopic features of the major and minor papillae were examined in 59 and 13 patients with AIP. After steroid therapy, changes of the major and minor papillae were observed in 5 and 6 patients. The major and minor papillae were observed with narrow band imaging in 24 and 6 patients. Biopsy specimens from the major (n = 50) and minor (n = 13) papillae were immunostained using an anti-IgG4 antibody.

RESULTS

Endoscopic features of the major and minor papillae were abnormal in 26 patients (44%; swelling [n = 20] and redness [n = 14]) and 5 patients (38%; swelling [n = 5]). Swelling of the pancreatic head, irregular narrowing of the main pancreatic duct of the pancreatic head, stenosis of the lower bile duct, and abundant infiltration of IgG4-positive plasma cells were more frequent in the patients with an abnormal major papilla compared with those with a normal major papilla. On narrow band imaging, dilated vessels were observed in abnormal papillae. After therapy, swelling of the major and minor papillae improved in all 4 and 2 patients.

CONCLUSIONS

Endoscopic features of the major and minor papillae were abnormal in 44% and 38% of the patients with AIP.

Role of endoscopy in the diagnosis of autoimmune pancreatitis and immunoglobulin G4-related sclerosing cholangitis

Autoimmune pancreatitis (AIP) must be differentiated from pancreatic carcinoma, and immunoglobulin (Ig)G4-related sclerosing cholangitis (SC) from cholangiocarcinoma and primary sclerosing cholangitis (PSC). Pancreatographic findings such as a long narrowing of the main pancreatic duct, lack of upstream dilatation, skipped narrowed lesions, and side branches arising from the narrowed portion suggest AIP rather than pancreatic carcinoma. Cholangiographic findings for PSC, including band-like stricture, beaded or pruned-tree appearance, or diverticulum-like outpouching are rarely observed in IgG4-SC patients, whereas dilatation after a long stricture of the bile duct is common in IgG4-SC. Transpapillary biopsy for bile duct stricture is useful to rule out cholangiocarcinoma and to support the diagnosis of IgG4-SC with IgG4-immunostaining. IgG4-immunostaining of biopsy specimens from the major papilla advances a diagnosis of AIP. Contrast-enhanced endoscopic ultrasonography (EUS) and EUS elastography have the potential to predict the histological nature of the lesions. Intraductal ultrasonographic finding of wall thickening in the non-stenotic bile duct on cholangiography is useful for distinguishing IgG4-SC from cholangiocarcinoma. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used to exclude pancreatic carcinoma. To obtain adequate tissue samples for the histological diagnosis of AIP, EUS-Tru-cut biopsy or EUS-FNA using a 19-gauge needle is recommended, but EUS-FNA with a 22-gauge needle can also provide sufficient histological samples with careful sample processing after collection and rapid motion of the FNA needles within the pancreas. Validation of endoscopic imaging criteria and new techniques or devices to increase the diagnostic yield of endoscopic tissue sampling should be developed.

Distinguishing autoimmune pancreatitis from pancreaticobiliary cancers: current strategy

OBJECTIVE

A review of the literature to identify current modalities for the diagnosis of autoimmune pancreatitis (AIP) with the objective of establishing a strategy to distinguish it from pancreaticobiliary cancers.

BACKGROUND

Pancreatic and biliary manifestations of AIP mimic pancreaticobiliary cancers. Misdiagnosis of AIP can result in major surgery for a steroid-responsive disease.

METHODS

A review of the literature was performed to identify recent advances in the diagnosis of AIP and evaluate outcomes with various diagnostic strategies to minimize operative intervention for an autoimmune disease.

RESULTS

Diagnostic criteria for AIP are based on histology, imaging, serology, extrapancreatic organ involvement, and response to steroid therapy. The most commonly involved extrapancreatic sites are bile duct, kidney, and retroperitoneum. The Mayo Clinic diagnostic strategy utilizes core biopsy of the pancreas and the Japanese strategy depends on a characteristic pancreatogram. The rate of operative intervention was similar with both strategies and none of the patients with cancer received steroid therapy. Immunoglobulin G subtype 4 (IgG4)-associated cholangitis mimics cholangiocarcinoma and presence of more than 10 IgG4-positive plasma cells/high power field on endoscopic biopsy of the bile duct was diagnostic for AIP in 88% patients. Biliary complications and early relapse are common after surgical resection and immunomodulatory drugs can maintain long-term remission.

CONCLUSION

Criteria based on histology, imaging, endoscopy, serology, extrapancreatic organ involvement, and response to steroid therapy improve the diagnostic yield for AIP. Application of diagnostic and therapeutic protocols by a multidisciplinary team will optimize outcomes with a decline in the rate of operative intervention for AIP, a steroid-responsive disease with propensity for relapse.

CT virtual endoscopy of the ampulla of Vater: preliminary report

AIM

To explore multi-slice spiral CT (MSCT) virtual endoscopy (CTVE) in the detection of Vater's ampulla lesions.

METHODS

In addition to 30 healthy volunteers, 18 cases of common bile duct stones, and 7 cases of ampullary carcinoma were scanned with MSCT including virtual endoscopy (VE) reconstruction. Patterns of the duodenal papilla were then observed, and its size was measured.

RESULTS

Reconstructed images of CTVE in the volunteers showed that the normal type of the duodenal papilla was nodular in 16 cases, V-shaped in 8 cases, and Y-shaped in 6 cases. Its mean diameter was 0.84 ± 0.17 cm in the healthy volunteers; in patients with common bile duct stones of nodular type, mean diameter was 1.72 ± 0.32 cm. In ampullary cancer patients with an irregular protruded type, its diameter was 2.30 ± 0.85 cm, Overall the mean differences between the groups were statistically significant (P < 0.001).

CONCLUSION

CTVE is a convenience, no-wound, and precise clinical examination mode utilizing which the shape of duodenal papilla can be observed, and size of the latter can be measured.

Usefulness of endoscopic biopsy using FOXP3+ Treg up-regulation in the duodenal papilla in the differential diagnosis between autoimmune pancreatitis and pancreatic cancer

BACKGROUND AND STUDY AIMS

Expression of the forkhead/winged helix family of transcription factor P3+ regulatory T cells (FOXP3(+) Treg), a master gene of regulatory T cells (Treg) is observed in patients with autoimmune pancreatitis (AIP). We investigated the usefulness of detection of FOXP3(+) Treg in the main duodenal papilla for differential diagnosis between AIP and pancreatic cancer (Pca).

PATIENTS AND METHODS

Firstly, we determined the cut-off value of FOXP3 expression in duodenal papilla taken from the patients with AIP (n = 22) and chronic pancreatitis (n = 21). Data from 32 patients with AIP and 30 patients with Pca who had undergone endoscopic biopsy were then studied. The numbers of FOXP3(+) Treg-positive lymphocytes and IgG4-positive plasma cells per high-power field (HPF) were counted in all the histopathological specimens.

RESULTS

The areas under the receiver-operating characteristic (AUROC) curves for FOXP3(+) and IgG4 expression were 0.934 and 0.953, respectively. Cut-off values calculated based on AUROC data were 14/HPF in FOXP3 and 10/HPF in IgG4. Seropositivity for IgG4 was observed in 22 out of the 31 patients with AIP (sensitivity 71.0%, specificity 84.6%, accuracy 75.0%). Significant infiltration of the major duodenal papilla by FOXP3(+) lymphocytes (≥ 14/HPF) was recognized in 18 of the 32 patients with AIP (sensitivity 56.3%, specificity 100%, accuracy 77.4%). Significant infiltration of the major duodenal papilla by IgG4-positive plasma cells (≥ 10/HPF) was recognized in 27 of the 32 patients with AIP (sensitivity 84.4%, specificity 80.0%, accuracy 82.3%).

CONCLUSIONS

Observation of FOXP3(+) cells in the main duodenal papilla may be useful in the differential diagnosis between AIP and Pca.

Factors predictive of relapse and spontaneous remission of autoimmune pancreatitis patients treated/not treated with corticosteroids

BACKGROUND

Relapse and spontaneous remission (SR) are characteristic features of autoimmune pancreatitis (AIP).

AIM AND METHODS

We conducted a study to determine if the predictive factors might be potentially related to the relapse in 70 consecutive AIP patients. Regarding SR, we studied the data of patients without corticosteroid treatment (CST).

RESULTS

CST was administered to 60% (42/70) of the patients; however, relapse was noted in 45.2% (19/42) of these patients. In 95% (18/19) of the AIP patients developing relapse, the relapse occurred within 3 years. The relapse rate was 80% (12/15) in the AIP patients administered CST for less than 12 months and 25.9% (7/27) in those administered CST for over 12 months (p < 0.01). The results of univariate analysis revealed significant association of relapse with the presence of jaundice, IgG4 seropositivity, presence of diffuse pancreas swelling, duodenal papillitis (DP), history of initial CST, and history of supportive treatment (p < 0.05), whereas multivariate analysis revealed that IgG4 seropositivity (OR 10.506, p = 0.0422) and the presence of jaundice (OR 6.945, p = 0.0174) are significant independent factors predictive of relapse in AIP patients. SR was recognized in 65.0% (13/20) of AIP patients without CST. The results of univariate analysis revealed that SR was associated with IgG4 seropositivity (p < 0.05), and multivariate analysis identified IgG4 seropositivity (OR 0.032, p = 0.0092) as a significant independent factor predictive of SR in these cases.

CONCLUSION

AIP patients with IgG4 seropositivity and jaundice are at a higher risk of relapse and they could therefore be candidates for over 3 years of maintenance CST. AIP patients with IgG4 seronegativity have a high likelihood of SR.

IgG4-related sclerosing cholangitis and autoimmune pancreatitis: histological assessment of biopsies from Vater's ampulla and the bile duct

BACKGROUND AND AIM

Autoimmune pancreatitis is commonly associated with immunoglobulin (Ig) G4-related sclerosing cholangitis (IgG4-SC). The discrimination between IgG4-SC and pancreatobiliary malignancies or primary sclerosing cholangitis (PSC) is now an important issue. The present study was carried out to examine the usefulness of endoscopic biopsies from Vater's ampulla and the bile duct to diagnose IgG4-SC.

METHODS

The present study included 29 IgG4-SC patients (26 with both pancreatitis and cholangitis, and 3 with cholangitis only), 6 PSC patients, and 27 pancreatobiliary carcinoma patients. All patients underwent endoscopic biopsies from Vater's ampulla and the common bile duct. Biopsied specimens were histologically examined using immunostaining for IgG4.

RESULTS

For the ampullary and bile duct biopsies, the IgG4-SC samples had a significantly greater number of IgG4-positive plasma cells than the PSC or pancreatobiliary carcinoma specimens. In addition, bile duct biopsies from five patients (17%) with IgG4-SC showed diffuse inflammatory cell infiltration with irregular fibrosis corresponding to the histological features of lymphoplasmacytic sclerosing pancreatocholangitis. Based on the threshold of 10 IgG4-positive plasma cells per high power field, the diagnostic rates of the ampullar and bile duct biopsies were both 52% (15/29 cases). Twenty-one patients (72%) had more than 10 IgG4-positive plasma cells in at least one biopsy. The bile duct biopsy was significantly valuable for IgG4-SC patients with swelling of the pancreatic head.

CONCLUSION

The present study suggested that ampullar and bile duct biopsies are useful for diagnosing IgG4-SC.

Endoscopic appearance of the minor papilla predicts findings at pancreatography

BACKGROUND

The minor papilla serves as a site of alternative pancreatic duct drainage via the accessory pancreatic duct.

AIMS

The objectives of this study were to assess the endoscopic appearance of the minor papilla for characteristics that might predict increased accessory pancreatic duct flow and hence suggest pathology of the downstream pancreatic ductal system.

METHODS

This was a nonrandomized, prospective analysis of consecutively enrolled patients from a tertiary care medical center (Maine Medical Center, Portland, Maine). The study cohort consisted of consecutive patients presenting for endoscopic retrograde cholangiopancreatography (ERCP) without prior pancreaticobiliary endotherapy or ductography.

RESULTS

Sixty-four patients received a minor papilla score prior to ERCP. A normal pancreatogram was found in 37 of 64 (57.8%) patients; the remaining 27 (42.2%) patients had an abnormal pancreatogram. The median minor papilla bulge score was 0.49 (range 0-3) in the normal pancreatogram group and 2 (range 0-3) in the abnormal pancreatogram group (P < 0.0001). The median minor papilla orifice score of those with a normal pancreatogram was 0 (range 0-2) compared to 2 (range 0-3) in the abnormal pancreatogram group (P < 0.001). The median minor papilla cumulative score of 1 (range 0-5) for the normal pancreatogram group was significantly less than that for the abnormal pancreatogram group (3, range 0-6, P < 0.0001), resulting in a sensitivity of 96.3% for an abnormal pancreatogram. The minor papilla orifice was noted to be either gaping or actively dripping pancreatic juice in four out of five patients with pancreas divisum.

CONCLUSIONS

A minor papilla without bulging or a visible orifice would suggest a normal pancreatogram at ERP. Conversely, an abnormal minor papilla, particularly a patent minor papilla orifice, should raise suspicion of pancreatic ductal pathology and can help direct pancreatic endotherapy at the major or minor papillae.

Differentiating sclerosing cholangitis caused by autoimmune pancreatitis and primary sclerosing cholangitis according to endoscopic duodenal papillary features

BACKGROUND

Differentiating primary sclerosing cholangitis (PSC) and sclerosing cholangitis caused by autoimmune pancreatitis (SC-AIP) is often challenging. Recently, endoscopic findings of the duodenal papilla in cases with AIP or PSC were reported by Unno and Parlak, although the endoscopic differentiation of these 2 conditions has not yet been fully clarified.

OBJECTIVE

Our purpose was to clarify the endoscopic findings of the duodenal papilla in patients with SC-AIP and those with PSC and to determine criteria for the differentiation of these conditions.

DESIGN

Case series.

SETTING

Retrospective.

PATIENTS

Twenty-seven patients with SC-AIP and 12 patients with PSC who had undergone ERCP were identified from our database. We reviewed these records to determine whether the duodenal papillary findings (swollen papilla/normal papilla/small papilla) might be potentially useful for differentiating SC-AIP and PSC. Immunohistopathological findings for the duodenal papilla were also examined by using immunoglobulin G4 (IgG4) among the infiltrating plasma cells.

INTERVENTIONS

ERCP, biopsy specimen taken from duodenal papilla.

MAIN OUTCOME MEASUREMENTS

The presence of a swollen duodenal papilla with IgG4-positive plasma cells was useful for discriminating SC-AIP from with PSC.

RESULTS

A swollen duodenal papilla was observed in 63% (17/27) of the patients with SC-AIP, whereas there was no swelling of the duodenal papilla of the patients with PSC. A small papilla was recognized in 50% (6/12) of the patients with PSC. IgG4-positive plasma cells in the duodenal papilla were significantly detected in the patients with SC-AIP but not in the patients with PSC.

LIMITATION

Single-center study.

CONCLUSIONS

Characteristic duodenal endoscopic papillary features in patients with SC-AIP, such as a swollen duodenal papilla and positive immunostaining for IgG4, might be helpful for discriminating this condition from PSC.

Evaluation of unusual causes of pancreatitis: role of cross-sectional imaging

There are widely diverse causes of pancreatitis. Gallstone and alcohol have been recognized as the most common causes of pancreatitis accounting for 90% of cases. However, acute and chronic pancreatitis may also result from a variety of uncommon causes. The determination of the etiology is important for patient management and prevention of recurrence. Sludge is the most common cause of idiopathic or recurrent acute pancreatitis. Endoscopic ultrasonography is considered as the most accurate diagnostic test for this abnormality. Computed tomography (CT) and magnetic resonance imaging (MRI) have only a limited role in the diagnosis of sludge. However, papillitis observed on the contrast-enhanced CT and MR may provide clues to the detection of pancreatitis secondary to sludge, a small stone or a recently passed stone. Radiological studies, clinical presentation and laboratory data can be helpful in determining the etiology of unusual causes of pancreatitis such as anatomic anomalies, autoimmune pancreatitis, groove pancreatitis, and traumatic pancreatitis.

Clinical factors predictive of spontaneous remission or relapse in cases of autoimmune pancreatitis

BACKGROUND

The rates of spontaneous remission and relapse of autoimmune pancreatitis (AIP) are not known.

OBJECTIVE

To study the clinicopathologic factors predictive of remission and relapse in cases of AIP.

DESIGN

Retrospective study.

PATIENTS

Of the 20 patients with AIP, complete response to steroid therapy was recognized in 12 patients, and the remaining 8 patients improved without steroid therapy. Seven patients experienced a relapse.

RESULTS

Patients who were seronegative for immunoglobulin (Ig) G4, had no obstructive jaundice, no diabetes mellitus, no swelling of the duodenal papilla, negative staining of the duodenal papilla for IgG4, and focal pancreatic swelling showed a greater tendency toward spontaneous remission (P < .05). The results of multivariate analysis revealed that negative staining of the duodenal papilla for IgG4 was the only independent predictor of spontaneous remission of AIP (odds ratio [OR] 1.395, P = .0304). Seropositivity for IgG4, diffuse swelling of the pancreas, and the presence of stricture in the lower part of the bile duct were significantly associated with a relapse of AIP (P < .05) according to the results of univariate analysis, whereas the results of multivariate analysis revealed only diffuse pancreatic swelling as an independent predictor of a relapse of AIP (OR 26.197, P = .0331).

CONCLUSIONS

Endoscopic findings are of useful prognostic value, because patients with AIP and with negative staining of the duodenal papilla for IgG4 appeared to have a higher frequency of remission without steroid therapy. Patients with AIP and with diffuse pancreatic swelling were found to be at an increased risk of relapse after the initial steroid administration.

Clinical significance of swollen duodenal papilla in autoimmune pancreatitis

OBJECTIVES

To evaluate the clinical significance of a swollen main duodenal papilla and the associated immunohistopathologic findings in patients with autoimmune pancreatitis (AIP).

METHODS

Seventeen consecutive patients with AIP registered between April 2001 and October 2005 who underwent both endoscopic retrograde cholangiopancreatography and endoscopic biopsy were enrolled in this study. The endoscopic features, stromal inflammatory cell infiltrate (SICI), and results of immunohistochemical examination of the duodenal papilla using IgG4, CD3, and CD79a antibodies were retrospectively reviewed. These findings in the AIP patients were compared with those in 12 patients with chronic alcoholic tumor-forming pancreatitis (CAP). The numbers of cells in the SICI and of IgG4-positive plasma cells per high-power field were counted in all the histopathologic specimens.

RESULTS

A swollen main duodenal papilla was observed in 11 (11 [64.7%]/17) patients with AIP and 4 (4 [33.3%]/12) patients with CAP (P < 0.05). Resolution of the swollen main duodenal papilla was observed in all of these 11 patients with AIP (11 [100%]/11) in response to treatment with corticosteroids. On the other hand, the 6 patients without elevated serum IgG4 or a swollen duodenal papilla, but with a swollen pancreas, improved even without corticosteroid treatment. The number of cells in the SICI in the AIP patients was significantly higher than that in the CAP patients. Although in 13 of 17 AIP patients, infiltration by IgG4-positive plasma cells was detected in the duodenal papilla, no such significant infiltration of the duodenal papilla by IgG4-positive plasma cells was observed in the patients with CAP (P < 0.05). More predominant T-cell infiltration of the duodenal papilla was recognized in the AIP patients than in the CAP patients (P < 0.05).

CONCLUSIONS

These results suggest that a swollen main duodenal papilla with IgG4-positive plasma cell and T-cell-dominant infiltration and an abundant stromal cell infiltrate are characteristic findings in AIP. We suggest that these findings may be valuable adjuncts to the diagnosis of AIP as well as for selecting suitable candidates for corticosteroid therapy.

CT evaluation of the bulging papilla with endoscopic correlation

A variety of pathologic conditions can cause abnormalities of the ampulla of Vater. A bulging papilla is frequently encountered at computed tomography (CT) and can be seen in healthy individuals as well as in patients with various pathologic conditions such as papillitis, ampullary cancer, and intraductal papillary mucinous tumor. Mural thickening and certain attenuation patterns seen at contrast material-enhanced CT can help differentiate pathologic papilla from normal papilla. Increased targetlike enhancement of the papilla is likely to represent a benign condition such as papillitis, whereas an enhancing polypoid mass or focal asymmetric or irregular thickening with prolonged enhancement in the ampulla of Vater indicates a malignant condition such as ampullary or periampullary carcinoma. Although CT often does not clarify the exact cause of bulging, adequate duodenal distention may allow detection of an abnormal papilla, thereby providing additional information about other abnormalities in the pancreaticobiliary system. Thus, CT findings may prove useful for subsequent imaging studies such as magnetic resonance (MR) cholangiography or endoscopy. MR cholangiography may be equivalent to CT for identifying a bulging papilla and superior for distinguishing the underlying cause. However, endoscopy with or without biopsy is the best method for making a definitive diagnosis in patients with a bulging papilla. Familiarity with the normal imaging anatomy of the periampullary region and with the imaging features of the various pathologic causes of a bulging papilla may be useful in making the diagnosis.

Usefulness of biopsying the major duodenal papilla to diagnose autoimmune pancreatitis: A prospective study using IgG4-immunostaining

AIM: To examine the histological and immunohistochemical findings of biopsy specimens taken from the major duodenal papilla of autoimmune pancreatitis (AIP) patients.

METHODS: The major duodenal papilla in the resected pancreas of 3 patients with AIP and of 5 control patients [pancreatic carcinoma (n = 3) and chronic alcoholic pancreatitis (n = 2)] was immunostained using anti-CD4-T cell, CD8-T cell and IgG4 antibodies. Forceps biopsy specimens taken from the major duodenal papilla of 2 patients with AIP and 5 control patients with suspected papillitis were prospectively taken during duodenoscopy and immunohistochemically examined.

RESULTS: Moderate or severe lymphoplasmacytic infiltration including many CD4-positive or CD8-positive T lymphocytes and IgG4-positive plasma cells (≥10/HPF), was observed in the major duodenal papilla of all 3 patients with AIP. The same findings were also detected in the biopsy specimens taken from the major duodenal papilla of 2 patients with AIP, but in controls, there were only a few (≤3/HPF) IgG4-positive plasma cells infiltrating the major duodenal papilla.

CONCLUSIONS: An abundant infiltration of IgG4-positive plasma cells is specifically detected in the major duodenal papilla of patients with AIP. Although this is a preliminary study, IgG4-immunostaining of biopsy specimens taken from the major duodenal papilla may support the diagnosis of AIP.

EUS findings in patients with autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis is an increasingly recognized benign condition with a presentation similar to pancreatic neoplasia but responds to corticosteroid therapy. Clinical features, ERCP, and CT findings have been described. This study assessed the EUS and EUS-guided FNA features of proven autoimmune pancreatitis.

METHODS

The diagnosis of autoimmune pancreatitis was based on examination of surgical resection specimens or typical clinical findings (elevated immunoglobulin G level, no evidence of malignancy, characteristic non-EUS imaging studies, and clinical improvement, especially in response to treatment with a corticosteroid).

RESULTS

Presenting manifestations in 14 patients included obstructive jaundice, abdominal pain, and weight loss. Ten patients underwent surgery (including exploratory surgery). Six were successfully treated with corticosteroid. EUS revealed diffuse hypoechoic pancreatic enlargement (8/14) or a focal irregular hypoechoic mass (6/14). Features of chronic pancreatitis were not noted. EUS-guided FNA of the pancreas was suggestive of chronic inflammatory pancreatitis in 9 of 12 patients. Celiac and peripancreatic lymphadenopathy (up to 3 cm in diameter) was present in 6 patients. EUS-guided FNA of lymph nodes (3/4) did not reveal evidence of malignancy. Vascular involvement was noted in 3 patients.

CONCLUSIONS

The EUS features of autoimmune pancreatitis are easily mistaken for malignancy. However, a diffusely hypoechoic, enlarged pancreas, together with chronic inflammatory cells in aspirated cytologic specimens, is supportive of the diagnosis of autoimmune pancreatitis. When combined with clinical data, EUS and EUS-guided FNA may support a diagnosis of autoimmune pancreatitis, may warrant a trial of corticosteroid, and thereby may prevent unnecessary surgery.

Autoimmune pancreatitis associated with immune-mediated inflammation of the papilla of Vater: report on two cases

Autoimmune pancreatitis (AIP) is defined histologically by periductal and interacinar lymphocytic infiltration. Immunohistochemically, the majority of these lymphocytes are identified as T cells. Epithelial HLA-DR antigen expression was also described as a marker of autoimmunity in this type of chronic pancreatitis. We report 2 cases, a 56-year-old man and a 29-year-old woman, with AIP associated with immune-mediated inflammation of the main duodenal papilla (MDP). Serologically, antinuclear antibody positivity was detected in the male patient. The female patient, treated medically for ulcerative proctitis, had no serological evidence of autoimmune disease. Macroscopic papillitis was present only in the male patient, and endoscopic biopsy samples were taken from this swollen MDP. Since we could not exclude malignancy, a pancreatic head resection was performed in both patients. The histologic and immunohistochemical studies of the resected specimens showed periductal T-lymphocytic infiltration in the pancreatic and papillary tissues. Furthermore, HLA-DR-antigen expression was also demonstrated in epithelial cells of the pancreas and MDP. The immunohistological features of endoscopic biopsy samples from the swollen MDP were identical as in the surgically resected specimens. Immune-mediated inflammation of the MDP may be associated with AIP.