Suspected autoimmune pancreatitis--an indication for steroid treatment?

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

We herein report a unique form of autoimmune pancreatitis (AIP) spreading along the main pancreatic duct (MPD). A 70-year-old man was referred for a small lesion at the pancreatic neck, accompanying an adjacent cyst and dilated upstream MPD. Four years earlier, health checkup images had shown a pancreatic cyst but no mass lesion. Endoscopic ultrasonography showed a contrast-enhanced, tumorous lesion, mainly occupying the MPD. With a preoperative diagnosis of ductal neoplasms mainly spreading in the MPD, Whipple's resection was performed. The resected specimens showed MPD periductitis with IgG4-related pathology, indicating type 1 AIP. Clinicians should practice caution concerning the various AIP forms.

Steroid Therapy and Steroid Response in Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP), a unique subtype of pancreatitis, is often accompanied by systemic inflammatory disorders. AIP is classified into two distinct subtypes on the basis of the histological subtype: immunoglobulin G4 (IgG4)-related lymphoplasmacytic sclerosing pancreatitis (type 1) and idiopathic duct-centric pancreatitis (type 2). Type 1 AIP is often accompanied by systemic lesions, biliary strictures, hepatic inflammatory pseudotumors, interstitial pneumonia and nephritis, dacryoadenitis, and sialadenitis. Type 2 AIP is associated with inflammatory bowel diseases in approximately 30% of cases. Standard therapy for AIP is oral corticosteroid administration. Steroid treatment is generally indicated for symptomatic cases and is exceptionally applied for cases with diagnostic difficulty (diagnostic steroid trial) after a negative workup for malignancy. More than 90% of patients respond to steroid treatment within 1 month, and most within 2 weeks. The steroid response can be confirmed on clinical images (computed tomography, ultrasonography, endoscopic ultrasonography, magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography). Hence, the steroid response is included as an optional diagnostic item of AIP. Steroid treatment results in normalization of serological markers, including IgG4. Short- and long-term corticosteroid treatment may induce adverse events, including chronic glycometabolism, obesity, an immunocompromised status against infection, cataracts, glaucoma, osteoporosis, and myopathy. AIP is common in old age and is often associated with diabetes mellitus (33-78%). Thus, there is an argument for corticosteroid therapy in diabetes patients with no symptoms. With low-dose steroid treatment or treatment withdrawal, there is a high incidence of AIP recurrence (24-52%). Therefore, there is a need for long-term steroid maintenance therapy and/or steroid-sparing agents (immunomodulators and rituximab). Corticosteroids play a critical role in the diagnosis and treatment of AIP.

Pancreatic cystic lesions with atypical steroid response should be carefully managed in cases of autoimmune pancreatitis

BACKGROUND AND AIM

Pancreatic cysts have been reported in cases with autoimmune pancreatitis (AIP) and are often treated by corticosteroid; however, their response to steroid has not been determined fully. We aimed to see the incidence and steroid response of pancreatic cysts and the features of cysts without proper response in cases with AIP.

METHODS

Fifty-eight AIP cases were analyzed for the incidence and associated factors of pancreatic cystic lesions (≥ 10 mm). Of these, 47 cases, determined for steroid response, were retrospectively investigated for the factors associated with cyst change by corticosteroid therapy.

RESULTS

At initial diagnosis, 17 pancreatic cystic lesions were recognized in 13 cases (22.4%) of AIP, with an average size of 30 mm (range: 11-130 mm), associated with higher incidence of elevated serum amylase (38.5% vs 11.1%, P = 0.02). Of these 13 cases, nine cases with 10 cystic lesions underwent steroid therapy in our hospital. All of seven unilocular cysts were dramatically shrunken or vanished in a few months; meanwhile, three cases with multilocular cysts showed scarcely any steroid response (P = 0.008). Of these three cases, two cases were revealed to accompany pancreatic ductal carcinoma, in contrast to null of seven unilocular cysts (P = 0.07).

CONCLUSIONS

Pancreatic cystic lesions are sometimes recognized in cases with AIP, and most unilocular cysts can be minimized by corticosteroids. However, clinicians must be alert for atypical pancreatic cysts, such as multilocular cysts or cysts without obvious steroid response.

Diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a distinct form of chronic pancreatitis that is increasingly being reported. The presentation and clinical image findings of AIP sometimes resemble those of several pancreatic malignancies, but the therapeutic strategy differs appreciably. Therefore, accurate diagnosis is necessary for cases of AIP. To date, AIP is classified into two distinct subtypes from the viewpoints of etiology, serum markers, histology, other organ involvements, and frequency of relapse: type 1 is related to IgG4 (lymphoplasmacytic sclerosing pancreatitis) and type 2 is related to a granulocytic epithelial lesion (idiopathic duct-centric chronic pancreatitis). Both types of AIP are characterized by focal or diffuse pancreatic enlargement accompanied with a narrowing of the main pancreatic duct, and both show dramatic responses to corticosteroid. Unlike type 2, type 1 is characteristically associated with increasing levels of serum IgG4 and positive serum autoantibodies, abundant infiltration of IgG4-positive plasmacytes, frequent extrapancreatic lesions, and relapse. These findings have led several countries to propose diagnostic criteria for AIP, which consist of essentially similar diagnostic items; however, several differences exist for each country, mainly due to differences in the definition of AIP and the modalities used to diagnose this disease. An attempt to unite the diagnostic criteria worldwide was made with the publication in 2011 of the international consensus diagnostic criteria for AIP, established at the 2010 Congress of the International Association of Pancreatology (IAP).

Immunosuppressive drugs for the treatment of autoimmune pancreatitis

Autoimmune pancreatitis is one of the few diseases of the pancreas characterized by the possibility of curing the illness using immunosuppressant drugs. In this paper, the therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality were reviewed. Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open, such as a shared definition of the disease’s remission as well as autoimmune pancreatitis relapse, the dosage of steroids in the symptomatic phase of the disease and the duration of steroid therapy. Finally, it should be determined if other immunosuppressive nonsteroidal drugs could become first-line therapy in patients with autoimmune pancreatitis without jaundice and without atrophic pancreas.

Determination of steroid response by abdominal ultrasound in cases with autoimmune pancreatitis

BACKGROUND

Abdominal ultrasound is the most convenient modality for examining the morphology of the pancreas without physical stress. Steroid response is one of the key features of autoimmune pancreatitis; however, visualizing this response has not been evaluated using ultrasonography.

METHODS

Thirty-three consecutive autoimmune pancreatitis cases were retrospectively investigated for pancreatic and extrapancreatic lesions by ultrasonography before steroid therapy (n=33) and at two weeks (n=28) and one month (n=19) after starting oral steroid treatment.

RESULTS

Steroid treatment resulted in obvious shrinkage of the pancreatic lesion in 86% of the cases at two weeks and in 97% until one month. The maximum thickness of the pancreatic lesion was reduced from 28 to 22 mm in two weeks (P<0.0001), and pancreatic echographic findings improved in one month. Swelling of the peripancreatic lymph node was recognized in 48% and the aortic wall thickness in 12%, mostly reduced in two weeks (P=0.005). One case of definitive autoimmune pancreatitis revealed a steroid response only by following endoscopic retrograde cholangiopancreatography but not by ultrasonography or computed tomography.

CONCLUSIONS

Abdominal ultrasound revealed a steroid response in most cases of autoimmune pancreatitis within two weeks. Ultrasonography is suitable for initial confirmation of a steroid response; however, atypical cases showing insufficient response or not fulfilling criteria should undergo further examination.

Reduction of splenic volume by steroid therapy in cases with autoimmune pancreatitis

OBJECTIVES

Splenomegaly is sometimes recognized in autoimmune diseases and chronic pancreatitis; however, it has not yet been studied in autoimmune pancreatitis (AIP). The current study analyzed splenic volume and its associated factors in cases with AIP.

METHODS

Splenic volume was measured using computed tomography (CT) volumetric analysis in 46 cases with AIP and compared with 92 age- and gender-matched controls, and 46 disease controls (liver cirrhosis). Forty-six cases of chronic pancreatitis were also analyzed. Cases with AIP were investigated for factors associated with splenic volume and splenic volume change in response to steroid therapy.

RESULTS

Splenic volume was significantly larger in AIP (149 ± 86 ml) than in controls (97 ± 38 ml) and in CP (108 ± 79 ml) (P < 0.0001 and 0.0002), and was smaller than in disease controls (222 ± 134 ml) (P = 0.003). In AIP cases, splenic volume was associated with age and gender (P = 0.04 and 0.02), and splenomegaly was recognized in 20 % (9/46) of cases. Abnormal uptake of (18)F-fluorodeoxyglucose was not detected in the spleen by positron emission tomography. Splenic vein (SpV) was frequently involved in AIP (67 %), but was all recanalized after steroid therapy. Splenic volume in cases with AIP was minimized to 77 % of the original (122 ± 40 ml) (P < 0.0001) and this trend was remarkable in cases with splenomegaly (66 %). In AIP, high serum IL-2 receptor level, diffuse pancreatic enlargement, and SpV stenosis were significantly associated with splenic shrinkage due to steroid treatment (P = 0.002, 0.02, and 0.03).

CONCLUSIONS

Splenomegaly was sometimes recognized in cases with AIP; however, these cases can be treated with steroids, especially in cases with diffuse pancreatic swelling and SpV stenosis.

Functional pancreatic acinar cell carcinoma extending into the main pancreatic duct and splenic vein

INTRODUCTION

Pancreatic acinar cell carcinoma (ACC) has several unique characteristics, such as its progression pattern, spreading into the pancreatic duct and large blood vessels, and its secretion of pancreatic exocrine enzymes, which induces a paraneoplastic syndrome.

CASE REPORT

A 79-year-old Japanese man, with medical history of chronic renal failure, was referred to our institution for the examination of his abdominal pain and hyperglycemia. Plain computed tomography demonstrated a mass lesion, 4 cm in diameter, in the body of pancreas. Abdominal ultrasonogram demonstrated a bulky, hypoechoic mass extending into the splenic vein. Multiple hepatic nodules were detected on suspicion of metastasis. Positron emission tomography using 18F-fluorodeoxyglucoase revealed the tumor extended towards the pancreatic head through the main pancreatic duct. We obtained the tumor tissues from the pancreatic body using endoscopic ultrasound-guided fine-needle aspiration biopsy. Pathological diagnosis, supported by immunohistochemistry, was that of an ACC. In the follow-up period, he complained of subcutaneous nodules and arthralgia on his lower legs. Serum and intra-articular lipase levels were elevated, 6,420 I/U and 594 I/U, respectively. Histology of the skin lesion at the knee joint showed necrotizing panniculitis with eosinophilic infiltration. The patient was treated with weekly gemcitabine, but succumbed to acute respiratory distress unexpectedly 2 months after the initial diagnosis.

Endoscopic ultrasonography-guided fine needle aspiration biopsy using 22-gauge needle in diagnosis of autoimmune pancreatitis

BACKGROUNDS

The effectiveness of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has not been fully evaluated in the diagnosis of autoimmune pancreatitis (AIP).

AIM

To evaluate the effectiveness of EUS-FNA using 22-gauge needles in the diagnosis of AIP.

METHODS

EUS-FNA was examined in 85 patients with pancreatic mass, including 64 patients with pancreatic cancer and 21 patients with AIP. We investigated ability of EUS-FNA using 22-gauge needle for the differential diagnosis between AIP and pancreatic cancer. We also compared the factors concerning FNA procedures (number of needle passes, size of lesion, device, and amount of obtained pancreatic tissue) between two diseases.

RESULTS

Tissues obtained from 21 patients with AIP, although none of them demonstrated histology suspicious for malignancy, did not show histological evidence definitive for AIP. The amount of obtained pancreatic tissue was almost equal between two diseases in each pancreatic location. Sensitivity, specificity, overall accuracy, and negative predictive value of histological diagnosis of pancreatic cancer were 92.2%, 100%, 94.1%, and 80.8%, respectively.

CONCLUSION

EUS-FNA using 22-gauge needle distinguished benign from malignant pancreatic mass with >90% of accuracy, regardless of the location. Hence, it was helpful for the clinical diagnosis of AIP, however not providing satisfactory samples for the histological diagnosis of AIP.

Therapeutic management and clinical outcome of autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis, in comparison to other benign chronic pancreatic diseases, is characterized by the possibility of curing the illness with immunosuppressant drugs. The open question is whether to differentiate autoimmune pancreatitis as a primary or secondary disease based on the presence or absence of other autoimmune diseases or whether to consider autoimmune pancreatitis a clinical and pathological systemic entity, called IgG4-related sclerosing disease, since this aspect is also very important from a therapeutic point of view.

METHODS

In this paper, we reviewed the conventional therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality. We also reviewed some aspects which are important for the correct management of autoimmune pancreatitis, such as the surgical approach, the outcome of surgically treated autoimmune pancreatitis patients, whether medical treatment is always necessary, and, finally, when medical treatment should be initiated.

CONCLUSIONS

Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open such as the dosage of steroids in the acute phase and the duration of steroid therapy; finally, it should be assessed if other immunosuppressive non-steroidal drugs may become the first-line therapy in patients with AIP without jaundice and without atrophic pancreas.

Characteristics of autoimmune pancreatitis based on serum IgG4 level

BACKGROUND

Autoimmune pancreatitis is categorized as an IgG4-related autoimmune disease, mostly associated with serological alterations, however characteristics of autoimmune pancreatitis based on serum markers have not been fully evaluated.

METHODS

We evaluated demographics, symptoms, imaging and therapeutic outcome in 27 cases of autoimmune pancreatitis stratified by serum IgG4 level.

RESULTS

Twenty patients (74%) had elevated serum IgG4 and 7 (26%) had normal IgG4 levels. Compared to patients with normal serum IgG4 levels, patients with elevated IgG4 had higher incidence of jaundice at onset (14.3% vs. 80%, respectively; P=0.002), more frequent diffuse pancreatic enlargement at imaging (14.3% vs. 60%, respectively; P=0.04), significantly higher 18F-2-fluoro-2-deoxy-d-glucose uptake of pancreatic lesions (SUV max: 4.0 vs. 5.7, respectively; P=0.02), more frequent extrapancreatic lesions (42.9% vs. 85%, respectively; P=0.03). Response to steroids was recognized regardless of serum IgG4 level, however maintenance therapy was required more frequently amongst patients with elevated compared to normal IgG4 (85.7% vs. 33.3%, respectively; P=0.04).

CONCLUSIONS

Clinical features of autoimmune pancreatitis are different based on level of serum IgG4. Further studies are needed to clarify if normal serum IgG4 cases are a precursor of active type 1 or type 2 autoimmune pancreatitis.

A case of sclerosing cholangitis without pancreatic involvement thought to be associated with autoimmunity

Sclerosing cholangitis (SC) is one of the lesions frequently seen in IgG4-related systemic diseases, causing biliary stricture and mimicking bile duct carcinoma and primary sclerosing cholangitis (PSC). Although it often accompanies autoimmune pancreatitis (AIP), autoimmune-related SC without a pancreatic lesion is very rare. A 79-year-old woman was referred to our institution with suspected diagnosis of bile duct carcinoma in the previous hospital. The patient was not icteric and fever free, but with an elevated level of serum biliary enzyme, which lead us to detect this disease. Clinical images including computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS) demonstrated multiple strictures at the intrahepatic bile duct and enhanced wall thickness at the upper common bile duct, however her pancreas was normal. Repeated endoscopic procedures with multiple biopsies from the biliary strictures demonstrated fibrous ductal tissues with lymph-plasma cell infiltration (>10 IgG4(+) cells/HPF). By positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET), the uptake of FDG was not remarkable in areas other than the biliary lesions. Additional laboratory tests showed elevated levels of serum IgG (2,571 mg/dL), and γ-globulin (29%), and positive autoantibodies, but normal IgG4 (53.2 mg/dL). Together with clinical images, laboratory and histological findings, we diagnosed this patient as sclerosing cholangitis which was thought to be associated with autoimmunity. After one year of follow-up without steroid therapy, idiopathic thrombocytopenic purpura (ITP) developed with an increased level of serological markers. We encountered a rare case of sclerosing cholangitis expected to be associated with autoimmunity, which showed biliary strictures mimicking bile duct carcinoma and needed careful diagnosis. Unlike the typical AIP, the current case demonstrated distinct serological findings and no other organ involvement. Further study is needed to clarify the characteristics of sclerosing cholangitis associated with autoimmunity with a large number of cases.