Clinical significance of extrapancreatic lesions in autoimmune pancreatitis

Pancreatic fat in type 2 diabetes: Causal or coincidental?

Type 2 diabetes (T2D) is a multifactorial metabolic disorder affecting more than 450 million people across the globe. With the increasing prevalence of T2D and obesity, the role of fat accumulation at sites other than subcutaneous adipose tissue has received significant attention in the pathophysiology of T2D. Over the past decade and a half, a pressing concern has emerged on investigating the association of pancreatic fat accumulation or pancreatic steatosis with the development of disease. While a few reports have suggested a possible association between pancreatic fat and T2D and/or impaired glucose metabolism, a few reports suggest a lack of such association. Pancreatic fat has also been linked with genetic risk of developing T2D, prediabetes, reduced insulin secretion, and beta cell dysfunction albeit some confounding factors such as age and ethnicity may affect the outcome. With the technological advancements in clinical imaging and progress in assessment of pancreatic beta cell function, our understanding of the role of pancreatic fat in causing insulin resistance and development of various etiologies of T2D has significantly improved. This review summarizes various findings on the possible association of pancreatic fat accumulation with the pathophysiology of T2D.

The Clinical Utility of Soluble Serum Biomarkers in Autoimmune Pancreatitis: A Systematic Review

Autoimmune pancreatitis (AIP) is a rare etiological type of chronic pancreatitis. The clinical and radiological presentation of AIP often resembles that of pancreatic cancer. Identifying non-invasive markers for their early distinction is of utmost importance to avoid unnecessary surgery or a delay in steroid therapy. Thus, this systematic review was conducted to revisit all current evidence on the clinical utility of different serum biomarkers in diagnosing AIP, distinguishing AIP from pancreatic cancer, and predicting disease course, steroid therapy response, and relapse. A systematic review was performed for articles published up to August 2021 by searching electronic databases such as MEDLINE, Web of Science, and EMBASE. Among 5123 identified records, 92 studies were included in the qualitative synthesis. Apart from immunoglobulin (Ig) G4, which was by far the most studied biomarker, we identified autoantibodies against the following: lactoferrin, carboanhydrase II, plasminogen-binding protein, amylase-α2A, cationic (PRSS1) and anionic (PRSS2) trypsinogens, pancreatic secretory trypsin inhibitor (PSTI/SPINK1), and type IV collagen. The identified novel autoantigens were laminin 511, annexin A11, HSP-10, and prohibitin. Other biomarkers included cytokines, decreased complement levels, circulating immune complexes, N-glycan profile changes, aberrant miRNAs expression, decreased IgA and IgM levels, increased IgE levels and/or peripheral eosinophil count, and changes in apolipoprotein isoforms levels. To our knowledge, this is the first systematic review that addresses biomarkers in AIP. Evolving research has recognized numerous biomarkers that could help elucidate the pathophysiological mechanisms of AIP, bringing us closer to AIP diagnosis and its preoperative distinction from pancreatic cancer.

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

OBJECTIVES

This study aims to clarify the relationship between the changes of pancreatic size after glucocorticoid (GC) therapy and relapse in IgG4-related autoimmune pancreatitis (AIP).

METHODS

We prospectively enrolled 205 newly diagnosed IgG4-related AIP patients. 145 patients were followed up for more than 3 years. These patients were divided into three groups according to the changes of pancreatic size after treatment of 6 months: pancreatic swelling, normal size, and pancreatic atrophy. Baseline clinical and laboratory parameters were compared among three groups. Kaplan-Meier survival analysis was performed in the 134 patients based on GC therapy. Besides, Cox regression analysis and logistic regression analysis were performed to identify risk factors associated with relapse and the potential variables affecting changes of pancreatic size after treatment.

RESULTS

Age at diagnosis, white blood cell count, and serum IgG1 level at baseline were significantly different among the three groups. After treatment of 6 months, the pancreas of most patients (n = 81, 55.9%) could return to normal size, while persistent pancreatic swelling was found in 24.1% patients (n = 35), and atrophy was observed in 20.0% of the patients (n = 29). Kaplan-Meier survival analysis presented patients with pancreatic swelling after 6 months of GC therapy were more likely to relapse in the follow-up of 3 years. Persistent pancreatic swelling after treatment and salivary gland involvement at baseline were independent risk variables associated with relapse in IgG4-related AIP patients, while GC-based therapy was a protective factor of relapse. Logistic regression analysis revealed that older age at diagnosis was associated with pancreatic atrophy and higher baseline serum IgG1 level was associated with pancreatic swelling after treatment of 6 months.

CONCLUSIONS

Patients with persistent pancreatic swelling after GC-based therapy of 6 months were more likely to relapse in the follow-up of 3 years. Older age at diagnosis and higher baseline serum IgG1 level were potential variables associated with pancreatic atrophy or swelling after treatment of 6 months. Key Points • Patients with persistent pancreatic swelling after glucocorticoid-based therapy were more likely to relapse in IgG4-related autoimmune pancreatitis. • Older age at diagnosis was associated with pancreatic atrophy after glucocorticoid-based therapy. • Higher baseline serum IgG1 level was associated pancreatic swelling after glucocorticoid-based therapy.

Comprehensive analysis of protein-expression changes specific to immunoglobulin G4-related disease

BACKGROUND AND AIMS

Immunoglobulin 4 (IgG4)-related disease (IgG4-RD) is a lymphoproliferative disorder characterized by elevated serum IgG4 levels and tissue infiltration of IgG4-positive plasma cells. We analyzed the serum proteins, whose levels varied based on the disease state and treatment.

MATERIALS AND METHODS

Serum proteins from patients with IgG4-related disease and healthy subjects were resolved using two-dimensional electrophoresis, silver-stained, and scanned. Alternatively, the proteins were labeled with Cy2, Cy3, and Cy5 before electrophoresis. The proteins, whose expression differed significantly between patients and healthy individuals, and between before and after steroid treatment, were identified and validated using enzyme-linked immunosorbent assays.

RESULTS

Pre-treatment sera from patients with IgG4-related disease was characterized by increased levels of immunoglobulins such as IgG1, IgG4; inflammatory factors such as α-1 antitrypsin (A1AT); and proteins associated with immune system regulation such as clusterin and leucine-rich α-2-glycoprotein (LRG-1). The serum levels of A1AT, LRG-1 and clusterin, during treatment with prednisolone for up to 12 months revealed that LRG-1 levels were halved after 1 month of treatment, comparable to those in healthy subjects; LRG-1 levels remained normal until the end of treatment.

CONCLUSION

LRG-1 could serve as a novel biomarker of IgG4-related diseases.

Biliary Strictures: Etiologies and Medical Management

Biliary strictures have several etiologies that can broadly be classified into benign and malignant causes. The clinical presentation is variable with strictures identified incidentally on imaging or during the evaluation of routine laboratory abnormalities. Symptoms and cholangitis lead to imaging that can diagnose biliary strictures. The diagnosis and medical management of biliary strictures will be discussed in this article.

IgG4 related disease

IgG4-related disease (ER-IgG4) is a recognised systemic disease. It was described after patients diagnosed with autoimmune pancreatitis showed signs of extra-pancreatic disease. The clinical manifestation of these patients is subacute and is manifested by the appearance of pseudotumoral lesions, or inflammatory or fibrous tumours. Sometimes it can be serious as in the case of patients with cholangitis or large vessel vasculitis. Diagnostic criteria include, among others, serum IgG4 elevation and/or histological parameters. The 18F-FDG-PET/CT is useful in the initial diagnosis, biopsy guidance as well as in the assessment of response to therapy. It usually responds to steroid therapy.

Differentiation of focal autoimmune pancreatitis from pancreatic ductal adenocarcinoma

Autoimmune pancreatitis (AIP) is an inflammatory process of the pancreas that occurs most commonly in elderly males and clinically can mimic pancreatic adenocarcinoma and present with jaundice, weight loss, and abdominal pain. Mass-forming lesions in the pancreas are seen in the focal form of AIP and both clinical and imaging findings can overlap those of pancreatic cancer. The accurate distinction of AIP from pancreatic cancer is of utmost importance as it means avoiding unnecessary surgery in AIP cases or inaccurate steroid treatment in patients with pancreatic cancer. Imaging concomitantly with serological examinations (IgG4 and Ca 19-9) plays an important role in the distinction between these entities. Characteristic extra-pancreatic manifestations as well as favorable good response to treatment with steroids are characteristic of AIP. This paper will review current diagnostic parameters useful in differentiating between focal AIP and pancreatic adenocarcinoma.

[Inflammatory and infectious abdominal peritoneal and mesenterial processes]

BACKGROUND

Mesenterial and peritoneal inflammation represents a major clinical challenge regarding differential diagnosis. In this review article, a systematic overview of the most common causes such as autoimmune reaction, infarction with consecutive necrosis and infection caused by protozoa or bacteria is provided.

RESULTS

The common clinical features of all inflammatory peritoneal and mesenterial diseases are the nonspecific abdominal symptoms. Even in radiological imaging an overlap of imaging features such as lymphadenopathy and nodular mesenteric structures is typical. Frequently the radiologist can narrow the differential diagnosis based on clinical information and anamnesis resulting in an optimized clinical outcome.

CONCLUSION

Having a huge spectrum of etiologies for inflammatory peritoneal and mesenterial conditions the radiologist has to consider autoimmune diseases (IgG4-associated disease), acute infarction with necrosis and bacterial or protozoan infection.

Kidney Involvement in Patients with Type 1 Autoimmune Pancreatitis

Introduction: Autoimmune pancreatitis (AIP) type 1 is a special form of chronic pancreatitis with a strong lymphocytic infiltration as the pathological hallmark and other organ involvement (OOI). IgG4-related kidney disease (IgG4-RKD) was first reported as an extrapancreatic manifestation of AIP in 2004. The aim of the present study was to determine the frequency and clinical impact of kidney lesions observed in patients with AIP type 1. Methods: We performed a single-centre retrospective study on a prospectively collected cohort of patients with a histologically proven or highly probable diagnosis of AIP according to the International Consensus Diagnostic Criteria (ICDC) classification. Results: Seventy-one patients with AIP were evaluated. AIP type 1 was diagnosed in 62 (87%) patients. Kidney involvement was present in 17 (27.4%) patients with AIP type 1: 15 (88.2%) males and 2 (11.8%) females. Laboratory and/or imaging signs of kidney involvement were presented at the time of AIP diagnosis in eight (47.1%) patients. In other patients, the onset of kidney involvement occurred between four months and eight years following diagnosis. At the time of the diagnosis of kidney involvement, eight (47.1%) patients showed elevated creatinine, and nine (52.9%) patients showed normal serum creatinine. None of the patients were treated with dialysis. Conclusions: IgG4-RKD was present in 27.4% of patients with AIP type 1, with male gender predominance. In cases of early diagnosis and cortisone treatment, the clinical course was mild in most cases. Regular laboratory control of renal function should be a part of the follow-up of patients with AIP type 1.

Impact of sclerosing dacryoadenitis/sialadenitis on relapse during steroid therapy in patients with type 1 autoimmune pancreatitis

OBJECTIVES

Steroids are the first-line drugs for induction of remission in patients with type 1 autoimmune pancreatitis (AIP), and the usefulness of steroid maintenance therapy to prevent relapse has recently been reported. However, even during steroid therapy, a relatively large percentage of patients relapse and the predictive factors for relapse have not yet been elucidated. The aim of this study was to clarify the predictive factors for relapse of AIP patients during steroid therapy.

MATERIALS AND METHODS

The medical records of 76 patients with type 1 AIP with continued steroid therapy after induction of remission were analyzed retrospectively. The relapse rate during steroid therapy was evaluated, and the risk factors for relapse were investigated by univariate and multivariate analysis of clinical factors.

RESULTS

Relapse occurred in 28.9% (22/76) of the patients. The cumulative relapse rates were 10.5% at 1 year, 25.0% at 3 years, 34.9% at 5 years, and 43.0% at 10 years. In multivariate analysis, presence of sclerosing dacryoadenitis/sialadenitis at the time of initial diagnosis of AIP was an independent risk factor for relapse (HR 3.475, p = .009). The cumulative relapse rates of patients with sclerosing dacryoadenitis/sialadenitis reached 21.4% at 1 year, 56.0% at 3 years, and 78.0% at 5 years.

CONCLUSIONS

Sclerosing dacryoadenitis/sialadenitis was a predictive factor for relapse in type 1 AIP during steroid therapy; in such cases, strict follow-up is necessary with relapse in mind.

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.

Predictive Factors for Autoimmune Pancreatitis Relapse After 3 Years of Maintenance Therapy

OBJECTIVES

Oral corticosteroid treatment is the standard therapy for autoimmune pancreatitis (AIP) and is highly effective. However, relapse may occur during maintenance therapy (MT). We aimed to clarify the predictive factors for relapse after 3 years of MT for use in deciding on the continuation of long-term MT.

METHODS

Among 56 retrospectively recruited AIP patients who received corticosteroid remission induction therapy followed by MT for a minimum of 5 years, 38 subjects were enrolled after exclusion criteria and divided into the relapse group of patients who experienced relapse after 3 years of MT and the nonrelapse group of patients who did not.

RESULTS

According to multivariate analysis, at least 4 other organ involvement numbers at diagnosis (hazard ratio, 5.82; 95% confidence interval, 1.203-28.192) and IgG of 1400 mg/dL or greater at 3 years of MT (hazard ratio, 4.41; 95% confidence interval, 1.096-17.790) were predictive factors for relapse after MT for 3 years, with patients exhibiting both predictive factors having a higher cumulative relapse rate than those with 1 or fewer predictive factor.

CONCLUSIONS

We uncovered 2 predictive factors for AIP relapse after 3 years of MT. These findings will assist in deciding corticosteroid therapy regimens at 3 years of MT to minimize AIP relapse risk and adverse corticosteroid effects.

IgG4-related sclerosing cholangitis mimicking hilar cholangiocarcinoma (Klatskin tumor): a case report of a challenging disease and review of the literature

Background

Even though IgG4-related disease has gained increased attention worldwide, the diagnosis remains challenging. IgG4-related sclerosing cholangitis (IgG4-SC) is not well described in the western hemisphere and may mimic cholangiocarcinoma (CC), especially when occurring without other symptoms such as, e.g. concurrent pancreatitis or retroperitoneal fibrosis. We present a case to add further information to the diagnosis and treatment of this challenging disease.

Case report

A 60-year-old male patient presented with painless jaundice. Prior medical history showed diabetes mellitus type I, high blood pressure, and deep vein thrombosis. Diagnostic investigations were strongly suspicious of a Klatskin tumor, although biopsies were inconclusive. The tumor marker Carbohydrate Antigen 19-9 (CA 19-9) was elevated. Prior to the recommended surgery, the patient had two second opinions in two different university hospitals, both arguing for surgery as well. The patient received hilar resection with right hemihepatectomy. During the postoperative course, some major complications occurred, i.e. recurrent pleural effusion, abscess in the liver resection area, sepsis, ileus, and restricted liver metabolism. Treatment with prednisolone did not show any improvement. Approximately 3 months after surgery, the patient died in consequence of acute respiratory failure. Histology showed no signs of CC, but IgG4-SC could be diagnosed.

Conclusion

In the case of preoperative signs of CC, differential diagnosis of IgG4-SC needs to be considered, in particular, in cases with missing histologic proof of malignant disease.

Prognosis of type 1 autoimmune pancreatitis after corticosteroid therapy-induced remission in terms of relapse and diabetes mellitus

Background and aim

Relapse and diabetes mellitus (DM) are major problems for the prognosis of autoimmune pancreatitis (AIP). We examined the prognosis of type 1 AIP after corticosteroid therapy (CST)-induced remission in terms of relapse and DM.

Methods

The study enrolled 82 patients diagnosed with type 1 AIP who achieved remission with CST. We retrospectively evaluated the relapse rate in terms of the administration period of CST, clinical factors associated with relapse, and the temporal change in glucose tolerance.

Results

During follow-up, 32 patients (39.0%) experienced relapse. There was no significant clinical factor that could predict relapse before beginning CST. AIP patients who ceased CST within 2 or 3 years experienced significantly earlier relapse than those who had the continuance of CST (p = 0.050 or p = 0.020). Of the 37 DM patients, 15 patients (40.5%) had pre-existing DM, 17 (45.9%) showed new-onset DM, and 5 (13.5%) developed CST-induced DM. Patients with new-onset DM were significantly more likely to show improvement (p = 0.008) than those with pre-existing DM.

Conclusions

It was difficult to predict relapse of AIP based on clinical parameters before beginning CST. Relapse was likely to occur within 3 years after the beginning of CST and maintenance of CST for at least 3 years reduced the risk of relapse. The early initiation of CST for AIP with impaired glucose tolerance is desirable because pre-existing DM is refractory to CST.

Efficacy of Cyclophosphamide treatment for immunoglobulin G4-related disease with addition of glucocorticoids

Aim to evaluate the efficacy and safety of glucocorticoid monotherapy vs combination therapy of cyclophosphamide (CYC) for IgG4 related disease (IgG4-RD). 102 newly diagnosed IgG4-RD patients were enrolled and assigned to 2 groups: Group I was prednisone monotherapy (0.5-1.0 mg/kg.d, tapered gradually) and Group II was glucocorticoid and CYC (50-100 mg per day). Patients were assessed at different periods. Primary end point was relapse rate; secondary end points included response, remission rate and adverse effects. 52 patients were in Group I and 50 in Group II. At 1 month, both groups achieved obvious improvement. Accumulated relapse rate during 1 year was 38.5% in Group 1, including 12 cases with clinical relapse and 8 patients manifesting only serological relapse; whereas there was 12.0% of relapse in Group 2, only 1 with clinical relapse and other 5 patients got serological relapse. The mean flare time in Group II was significantly longer than that in Group I. All relapsing patients in Group I were sensitive to immunosuppressants. Most patients involving more than 6 organs in Group I relapsed during 1 year. IgG4 levels of relapse cases were significantly higher than non-relapsing patients at baseline. Bile duct, lacrimal glands and lymph nodes were commonly relapsed organs in Group I.

Intrathoracic Involvements of Immunoglobulin G4-Related Sclerosing Disease

To investigate clinical and radiological features of IgG4-related disease (IgG4-RD) patients with intrathoracic involvement. A prospective cohort study was performed and IgG4-RD patients were enrolled from January 2011 to March 2015 in Peking Union Medical College Hospital, in which the clinical and radiological characteristics of IgG4-RD patients with intrathoracic involvement were summarized. Out of total 248 cases with IgG4-RD, 87 cases had intrathoracic lesions, including 58 male cases and 29 female cases, with average age of 54.19 ± 13.80 years. Hilar and mediastinal lymphadenopathy were the most common manifestations of IgG4-related intrathoracic disease, accounting for 52.9% (46/87). Other imaging findings of pulmonary disease included: solid nodular (25.3%), round-shaped ground-glass opacities (9.2%), alveolar-interstitial type (20.7%), bronchovascular type (23.0%), pleural effusion (4.6%), and pleural nodules or thickening (16.1%). Only 27 patients presented with respiratory symptoms, including cough, breathless, chest pain, and asthma. Compared with patients without intrathoracic disease, IgG4-related intrathoracic disease had higher IgG4 and C-reactive protein level, and higher incidence of allergy, fever, and multi-organ involvement. Most of lung interstitial disease, mediastinal mass, and bronchial thickening were sensitive to corticosteroid and immunosuppressant therapy, while 36.3% (8/22) of solitary nodular lesions were unresponsive to treatment. Eight patients were on no treatment, with 5 cases remained stable, 2 patients improved spontaneously, and 1 patient was lost follow-up. Intrathoracic lesions are not rare in patients with IgG4-RD, involving bronchial thickening, nodules, ground glass opacity, pleural thickening/effusion, lymphadenopathy, etc. Efficacy of corticosteroid and immunosuppressant therapy were noted in most of patients with lung interstitial disease, mediastinal mass, and bronchial thickening.

Endoscopic retrograde cholangiopancreatography-related adverse events in patients with type 1 autoimmune pancreatitis

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) is frequently performed for the diagnosis and treatment of type 1 autoimmune pancreatitis (AIP). However, the prevalence of ERCP-related adverse events in patients with type 1 AIP has not been evaluated. We aimed to clarify the feasibility of ERCP in patients with type 1 AIP.

METHODS

We retrospectively reviewed 82 consecutive ERCP procedures performed in patients with type 1 AIP from 2004 to 2014 in one university hospital and three tertiary-care referral centers. One hundred four ERCP procedures in chronic pancreatitis and 1123 in non-AIP cohort were enrolled as control groups. We compared the incidence of post-ERCP pancreatitis (PEP) between type 1 AIP and control groups. We evaluated the incidence of ERCP-related adverse events and various predictive factors for hyperamylasemia after ERCP.

RESULTS

Pancreatography and cholangiography by ERCP were obtained in 78 (95.1%) and 76 (92.7%) patients, respectively. The incidence of PEP, cholangitis, and bleeding was 1.2% (1/82), 0%, and 1.2%, respectively. PEP occurred in type 1 AIP patient with diffuse parenchymal imaging, and the severity was mild. The incidences of PEP were 2.9% (3/104) and 5.4% (61/1123) in chronic pancreatitis and normal cohort, respectively. The incidence of PEP was slightly lower in type 1 AIP than non-AIP cohort (1.2% vs 5.8%, p = 0.119). There were no significant predictive factors for hyperamylasemia after ERCP in type 1 AIP.

CONCLUSIONS

The incidence of ERCP-related adverse events is low in patients with type 1 AIP. ERCP-related procedures are feasible in the diagnosis and treatment of AIP.

Efficacy of Steroid Pulse Therapy for Autoimmune Pancreatitis Type 1: A Retrospective Study

Autoimmune pancreatitis (AIP) is treatable with steroids, but relapse is frequent. The efficacy of steroid pulse therapy has been shown for various autoimmune diseases, but has not become established therapy. In this study, we reviewed the efficacy of steroid pulse therapy in 24 subjects who were diagnosed with AIP type 1 at our hospital. Patient characteristics, time-course of serum IgG4, and the cumulative relapse-free survival rate were compared between patients who received oral steroid therapy (oral group) and those who were treated with steroid pulse therapy (pulse group). Serum IgG4 was reduced significantly after therapy in both groups and the 5-year cumulative relapse-free survival rates in the two groups did not differ significantly (oral group 46.9%, pulse group 77.8%). However, in a subset of cases with diffuse pancreatic swelling, this rate was significantly lower in the oral group (33.3% vs. 100.0%, p = 0.046). These results suggest that steroid pulse therapy is effective for prevention of relapse in AIP patients with diffuse pancreatic swelling.

[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.

Imaging of the porta hepatis: spectrum of disease

A wide array of pathologic conditions can arise within the porta hepatis, which encompasses the portal triad (the main portal vein, common hepatic artery, and common bile ducts), lymphatics, nerves, and connective tissue. Major vascular diseases of the portal triad include thrombosis, stenosis, and aneurysm. Portal vein thrombosis can complicate liver cirrhosis and hepatocellular carcinoma and has important therapeutic implications. Hepatic artery thrombosis and stenosis require immediate attention to reduce graft loss in liver transplant recipients. Congenital (eg, choledochal cyst) and acquired (benign and malignant) diseases of the biliary system can manifest as mass lesions in the porta hepatis. Lymphadenopathy can arise from neoplastic and nonneoplastic entities. Uncommon causes of mass lesions arise from nerves (eg, neurofibroma, neurofibrosarcoma) and connective tissue (sarcomas) and are rare. The hepatoduodenal ligament is a peritoneal reflection at the porta hepatis and is an important route for the spread of pancreatic and gastrointestinal cancers. Imaging plays a major role in diagnosis and enables appropriate management. Ultrasonography accurately demonstrates anatomic variations and pathologic conditions and is the initial modality of choice for detection of vascular and biliary lesions. Multidetector computed tomography and magnetic resonance imaging allow characterization and differentiation of various masses in the porta hepatis. Imaging-guided interventions, including embolization and stent placement, also play a key role in disease management.

Type 1 autoimmune pancreatitis and IgG4-related sclerosing cholangitis is associated with extrapancreatic organ failure, malignancy, and mortality in a prospective UK cohort

OBJECTIVES

Type I autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-related SC) are now recognized as components of a multisystem IgG4-related disease (IgG4-RD). We aimed to define the clinical course and long-term outcomes in patients with AIP/IgG4-SC recruited from two large UK tertiary referral centers.

METHODS

Data were collected from 115 patients identified between 2004 and 2013, and all were followed up prospectively from diagnosis for a median of 33 months (range 1-107), and evaluated for response to therapy, the development of multiorgan involvement, and malignancy. Comparisons were made with national UK statistics.

RESULTS

Although there was an initial response to steroids in 97%, relapse occurred in 50% of patients. IgG4-SC was an important predictor of relapse (P<0.01). Malignancy occurred in 11% shortly before or after the diagnosis of IgG4-RD, including three hepatopancreaticobiliary cancers. The risk of any cancer at diagnosis or during follow-up when compared with matched national statistics was increased (odds ratio=2.25, CI=1.12-3.94, P=0.02). Organ dysfunction occurred within the pancreas, liver, kidney, lung, and brain. Mortality occurred in 10% of patients during follow-up. The risk of death was increased compared with matched national statistics (odds ratio=2.07, CI=1.07-3.55, P=0.02).

CONCLUSIONS

Our findings suggest that AIP and IgG4-SC are associated with significant morbidity and mortality owing to extrapancreatic organ failure and malignancy. Detailed clinical evaluation for evidence of organ dysfunction and associated malignancy is required both at first presentation and during long-term follow-up.

IgG4-related thyroiditis: a case report and review of literature

A 55-year-old male, with a positive medical history for hypothyroidism, treated with stable doses for years was admitted with subacute thyroiditis and a feeling of pain and pressure in the neck. Laboratory tests showed decrease in TSH levels, elevated erythrocyte sedimentation rate, and very high antithyroid antibodies. Owing to enlarging goiter and exacerbation in the patient's complaints, he was operated with excision of a fibrotic and enlarged thyroid lobe. Elevated IgG4 plasma levels and high IgG4/IgG plasma cell ratio on immunohistochemistry led to the diagnosis of IgG4-mediated thyroiditis. We concluded that IgG4-thyroiditis and IgG4-related disease should be considered in all patients with an aggressive form of Hashimoto's thyroiditis.

Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 III. Treatment and prognosis of autoimmune pancreatitis

The standard treatment for autoimmune pancreatitis (AIP) is steroid therapy, although some patients improve spontaneously. Indications for steroid therapy in AIP patients are symptoms such as obstructive jaundice, abdominal pain, back pain, and the presence of symptomatic extrapancreatic lesions. Prior to steroid therapy, obstructive jaundice should be managed by biliary drainage, and blood glucose levels should be controlled in patients with diabetes mellitus. The recommended initial oral prednisolone dose for induction of remission is 0.6 mg/kg/day, which is administered for 2-4 weeks. The dose is then tapered by 5 mg every 1-2 weeks, based on changes in clinical manifestations, biochemical blood tests (such as liver enzymes and IgG or IgG4 levels), and repeated imaging findings (US, CT, MRCP, ERCP, etc.). The dose is tapered to a maintenance dose (2.5-5 mg/day) over a period of 2-3 months. Cessation of steroid therapy should be based on the disease activity in each case. Termination of maintenance therapy should be planned within 3 years in cases with radiological and serological improvement. Re-administration or dose-up of steroid is effective for treating AIP relapse. Application of immunomodulatory drugs is considered for AIP patients who prove resistant to steroid therapy. The prognosis of AIP appears to be good over the short-term with steroid therapy. The long-term outcome is less clear, as there are many unknown factors, such as relapse, pancreatic exocrine or endocrine dysfunction, and associated malignancy.

Concurrent autoimmune pancreatitis and primary biliary cirrhosis: a rare case report and literature review

Background

Both autoimmune pancreatitis (AIP) and primary biliary cirrhosis (PBC) are related to various diseases. But the concurrence of AIP and PBC is extremely rare, with only 2 cases reported. Here we report the concurrence of AIP and PBC in a Chinese patient for the first time.

Case presentation

A 65-year-old male was admitted to our hospital with jaundice, pruritus, mild abdominal pain and darkening urine. Serum alkaline phosphatase, γ-glutamyltransferase, bilirubin and IgG4 were prominently elevated. The antimitochondrial antibody was positive. Radiological examination revealed diffusive enlargement of the pancreas. Pancreatic biopsy showed lymphoplasmacytic infiltration, fibrosis and abundant IgG4+ plasma cells. The patient was diagnosed with AIP and PBC. Nasobiliary tube was placed to facilitate biliary drainage. A combination therapy of steroid and UDCA was administered and the patient was gradually recovered, during which the patient was complicated with biliary infecion, herpes zoster and pulmonary abscess.

Conclusion

We present this case together with literature evidence to support the concurrence of AIP and PBC, share our experience of using combination therapy with steroid and UDCA, and raise the awareness of infectious complications in immunosuppressed patients.

Imaging biliary strictures--a pictorial review

The diagnosis of biliary diseases may be delayed or missed because of an unpredictable clinical course and presentation. Some biliary diseases carry the risk of morbidity and mortality and are difficult to treat. The purpose of this article is to revisit the various causes and the appearances of biliary strictures on different imaging modalities and to emphasize the role of magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) in their evaluation compared with endoscopic retrograde cholangiopancreatography. MRI with MRCP is advantageous to endoscopic retrograde cholangiopancreatography for being a 1-stop shop to provide biliary, soft tissue, and vascular information that is helpful for planning intervention or surgery. Thus it serves as a superb imaging modality for the evaluation of biliary strictures.

Diagnosis of IgG4-related sclerosing cholangitis

IgG4-related sclerosing cholangitis (IgG4-SC) is often associated with autoimmune pancreatitis. However, the diffuse cholangiographic abnormalities observed in IgG4-SC may resemble those observed in primary sclerosing cholangitis (PSC), and the presence of segmental stenosis suggests cholangiocarcinoma (CC). IgG4-SC responds well to steroid therapy, whereas PSC is only effectively treated with liver transplantation and CC requires surgical intervention. Since IgG4-SC was first described, it has become a third distinct clinical entity of sclerosing cholangitis. The aim of this review was to introduce the diagnostic methods for IgG4-SC. IgG4-SC should be carefully diagnosed based on a combination of characteristic clinical, serological, morphological, and histopathological features after cholangiographic classification and targeting of a disease for differential diagnosis. When intrapancreatic stenosis is detected, pancreatic cancer or CC should be ruled out. If multiple intrahepatic stenoses are evident, PSC should be distinguished on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining. Associated inflammatory bowel disease is suggestive of PSC. If stenosis is demonstrated in the hepatic hilar region, CC should be discriminated by ultrasonography, intraductal ultrasonography, bile duct biopsy, and a higher cutoff serum IgG4 level of 182 mg/dL.

Clinical evaluation of international consensus diagnostic criteria for type 1 autoimmune pancreatitis in comparison with Japanese diagnostic criteria 2011

OBJECTIVES

The objective of this study was to evaluate the International Consensus Diagnostic Criteria (ICDC) for type 1 autoimmune pancreatitis (AIP) in comparison with the Japanese criteria 2011 (JPS2011).

METHODS

We retrospectively investigated the usefulness of ICDC in comparison with JPS2011 in 64 patients with AIP and 90 patients with pancreatic cancer.

RESULTS

The sensitivity and specificity of ICDC for AIP were 98.4% (63/64) and 100% (90/90), respectively. The sensitivities and specificities of ductal imaging, serology, other organ involvement, and pancreatic histology were 74.1%, 89.1%, 53.1%, and 26.1% and 94.7%, 94.5%, 100%, and 100%, respectively. On the other hand, the sensitivities and specificities of JPS2011 for AIP were 84.4% (54/64) and 100% (90/90), respectively. The condition of all the 10 patients who were deniable or possible under the JPS2011 could be diagnosed as definitive AIP under the ICDC. The sensitivities and specificities of Japanese criteria 2006, Asian Diagnostic Criteria, and HISORt criteria were 80.6%, 84.4%, and 92.2% and 95.8%, 87.8%, and 100%, respectively.

CONCLUSIONS

The sensitivity and specificity of ICDC are higher than those of previous criteria. The JPS2011 is easy to handle for general practice, and specificity is very high. However, the sensitivity of JPS2011 is lower than that of ICDC, and improvement of sensitivity is to be hoped in the future.

Radiological diagnosis and staging of hilar cholangiocarcinoma

Hilar cholangiocarcinoma is a rare malignant tumor arising from the epithelium of the bile ducts. Surgery is still the only chance of potentially curative treatment in patients with perihilar cholangiocarcinoma. However, radical resection requires aggressive surgical strategies that should be tailored optimally according to the location, size and vascular invasion of the tumors. Accurate diagnosis and staging of these tumors is therefore critical for optimal treatment planning and for determining a prognosis. Multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and MR cholangiography are useful tools, both to diagnose and stage hilar cholangiocarcinoma. Modern imaging techniques allow accurate detection of the level of obstruction and the longitudinal and radial spread of the tumor. In addition, high-resolution MDCT and MR provide specific radiographic features to determine vascular involvement of anatomic structures, such as the hepatic artery or the portal vein, which are critical to decide the surgical strategy. Finally, radiological staging allows detection of patients with distant metastasis in the liver or peritoneum who will not benefit from a surgical approach.

Clinical and pathological differences between serum immunoglobulin G4-positive and -negative type 1 autoimmune pancreatitis

AIM: To identify clinical and pathological differences between serum immunoglobulin G4 (IgG4)-positive (SIP) and IgG4-negative (SIN) type 1 autoimmune pancreatitis (AIP) in South Korea.

METHODS: AIP was diagnosed by the international consensus diagnostic criteria. The medical records and pathology were retrospectively reviewed and IgG4-positive cells were counted in a high power field (HPF). Type I AIP was defined as a high serum level of IgG4 or histological finding. SIN type 1 AIP was defined as a histological evidence of type 1 AIP and a normal serum IgG4 level. The clinical and pathological findings were compared between the two groups. The analysis was performed using Student’s t test, Fischer’s exact test and Mann-Whitney’s U test. A P value of < 0.05 was considered statistically significant. As repeated comparison was made, P values of less than 5% (P < 0.05) were considered significant.

RESULTS: Twenty five patients with definite type 1 AIP (19 histologically and six serologically diagnosed cases) were enrolled. The mean tissue IgG4 concentrations were significantly higher in SIP than SIN group (40 cells per HPF vs 18 cells per HPF, P = 0.02). Among eight SIN patients, the tissue IgG4 concentrations were less than 15 cells per HPF in most of cases, except one. The sensitivity of serum IgG4 was 68% (17 SIP and eight SIN AIP). Other organ involvement was more frequently associated with SIP than SIN AIP (59% vs 26%, P = 0.016). However, the relapse rate and diffuse swelling of the pancreas were not associated with serum IgG4 level. The concentrations of IgG4-positive cells per HPF were higher in SIP than SIN AIP (40 vs 18, P = 0.02).

CONCLUSION: The sensitivity of serum IgG4 was 68% in type 1 AIP. High serum IgG4 level was associated with other organ involvement and tissue IgG4 concentration but did not affect the relapse rate in type 1 AIP.

Establishment of a serum IgG4 cut-off value for the differential diagnosis of IgG4-related sclerosing cholangitis: a Japanese cohort

BACKGROUND AND AIM

IgG4-related sclerosing cholangitis (IgG4-SC) must be precisely distinguished from primary sclerosing cholangitis and cholangiocarcinoma (CC) because the treatments are completely different. However, the pathological diagnosis of IgG4-SC is difficult. Therefore, highly specific non-invasive criteria such as serum IgG4 should be established. This study established a cut-off for serum IgG4 to differentiate IgG4-SC from respective controls using serum IgG4 levels measured in Japanese centers.

METHODS

A total of 344 IgG4-SC patients were enrolled in this study. As controls, 245, 110, and 149 patients with pancreatic cancer, primary sclerosing cholangitis, and CC, respectively, were enrolled. IgG4-SC patients were classified into three groups: type 1 (stenosis only in the lower part of the common bile duct), type 2 (stenosis diffusely distributed throughout the intrahepatic and extrahepatic bile ducts), and types 3 and 4 (stenosis in the hilar hepatic region) with 246, 56, and 42 patients, respectively. Serum IgG4 levels were compared, and the cut-offs were established.

RESULTS

The cut-off obtained from receiver operator characteristic curves showed similar sensitivity and specificity to that of 135 mg/dL when all IgG4-SC and controls were compared. However, a new cut-off value was established when subgroups of IgG4-SC and controls were compared. A cut-off of 182 mg/dL can increase the specificity to 96.6% (4.7% increase) for distinguishing types 3 and 4 IgG4-SC from CC. A cut-off of 207 mg/dL might be useful for completely distinguishing types 3 and 4 IgG4-SC from all CC.

CONCLUSIONS

Serum IgG4 is useful for the differential diagnosis of IgG4-SC and controls.

The characteristics of ulcerative colitis associated with autoimmune pancreatitis

GOALS

To determine the prevalence of ulcerative colitis (UC) in autoimmune pancreatitis (AIP) patients in a tertiary referral hospital and to compare the clinical and pathologic characteristics and outcomes of UC associated with AIP (AIP-UC) and UC patients.

BACKGROUND

Recently, it was suggested that UC is associated with AIP. However, the prevalence of UC in AIP, together with the clinical characteristics and outcomes of AIP-UC are not clear.

STUDY

We retrospectively reviewed the medical records of AIP patients diagnosed at the Asan Medical Center.

RESULTS

Of the 104 patients with AIP, 6 (5.8%) were also diagnosed with UC. Serum immunoglobulin G (IgG) and IgG4 were elevated in 1 patient (16.7%), respectively, and 4 (66.7%) showed idiopathic duct-centric pancreatitis (type 2 AIP). Compared with 24 matched patients with UC only, AIP-UC patients had a lower body mass index (P=0.003), higher C-reactive protein levels (P=0.048), and higher Mayo scores (P=0.006) at diagnosis of UC. Two AIP-UC patients (33.3%), but none with UC only showed increased infiltration of IgG4-positive cells into the colonic tissues (P=0.006). During follow-up, 2 AIP-UC patients (33.3%) underwent colectomy and 1 (16.7%) died, but no colectomies or deaths occurred in the UC only group.

CONCLUSIONS

AIP patients seem to have a higher risk of UC compared with the general population. The increased IgG4-positive cellular infiltration in the colonic tissue suggests that UC may be an extrapancreatic manifestation of AIP.

Rethinking Ormond's disease: "idiopathic" retroperitoneal fibrosis in the era of IgG4-related disease

Idiopathic retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent retroperitoneal structures, particularly the ureters. A subset of idiopathic RPF cases can be associated with IgG4-related disease, but the frequency of this association is not clear. We selected 23 cases of idiopathic RPF and identified IgG4-related RPF cases based on the presence of IgG4+ plasma cells in the tissue, using an IgG4/IgG ratio cutoff of >40%. We then compared the IgG4-related RPF patients and the non-IgG4-related RPF patients in terms of both the presence of histopathologic features typical of IgG4-related disease and the simultaneous occurrence (or history) of other organ manifestations typical of IgG4-related disease. The IgG4-related RPF and non-IgG4-related RPF groups were also analyzed in terms of clinical, laboratory, and radiologic features and treatment review. We identified 13 cases of IgG4-related RPF (57% of the total cohort). The distinguishing features of IgG4-related RPF were histopathologic and extra-organ manifestations of IgG4-related disease. The IgG4-related RPF patients were statistically more likely than non-IgG4-related RPF patients to have retroperitoneal biopsies showing lymphoplasmacytic infiltrate (p = 0.006), storiform fibrosis (p = 0.006), or tissue eosinophilia (p = 0.0002). Demographics of the 2 groups, including a middle-aged, male predominance (mean age, 58 yr; 73% male), were similar. IgG4-related disease accounts for a substantial percentage of patients with "idiopathic" RPF. Histopathologic features such as storiform fibrosis, obliterative phlebitis, and tissue eosinophilia are critical to identifying this disease association. Extraretroperitoneal manifestations of IgG4-related disease are also often present among patients with IgG4-related RPF. Elevated IgG4/total IgG ratios in tissue biopsies are more useful than the number of IgG4+ plasma cells per high-power field in cases of RPF that are highly fibrotic.

Clinical diagnostic criteria of IgG4-related sclerosing cholangitis 2012

BACKGROUND

IgG4-sclerosing cholangitis (IgG4-SC) patients have an increased level of serum IgG4, dense infiltration of IgG4-positive plasma cells with extensive fibrosis in the bile duct wall, and a good response to steroid therapy. However, it is not easy to distinguish IgG4-SC from primary sclerosing cholangitis, pancreatic cancer, and cholangiocarcinoma on the basis of cholangiographic findings alone because various cholangiographic features of IgG4-SC are similar to those of the above progressive or malignant diseases.

METHODS

The Research Committee of IgG4-related Diseases and the Research Committee of Intractable Diseases of Liver and Biliary Tract in association with the Ministry of Health, Labor and Welfare, Japan and the Japan Biliary Association have set up a working group consisting of researchers specializing in IgG4-SC, and established the new clinical diagnostic criteria of IgG4-SC 2012.

RESULTS

The diagnosis of IgG4-SC is based on the combination of the following 4 criteria: (1) characteristic biliary imaging findings, (2) elevation of serum IgG4 concentrations, (3) the coexistence of IgG4-related diseases except those of the biliary tract, and (4) characteristic histopathological features. Furthermore, the effectiveness of steroid therapy is an optional extra diagnostic criterion to confirm accurate diagnosis of IgG4-SC.

CONCLUSION

These diagnostic criteria for IgG4-SC are useful in practice for general physicians and other nonspecialists.

Autoimmune pancreatitis: an update on classification, diagnosis, natural history and management

Autoimmune Pancreatitis (AIP) is a recently recognized chronic fibro-inflammatory disease of the pancreas. Although rare, its recognition continues to increase worldwide. Patients often present with painless obstructive jaundice mimicking pancreatic cancer. Two subtypes of AIP are known-type 1 is a multi-organ disease associated with IgG4; type 2 appears to be a pancreas-specific disorder. Dramatic response to steroid treatment is characteristic of both forms. A non-invasive diagnosis of type 1 AIP may be possible using diagnostic criteria (in ~70% cases) while diagnosis of type 2 requires histology. These subtypes differ in natural history- type 1 often relapses while initial reports suggest that type 2 does not. Long term complications include endocrine and exocrine insufficiency and in case of type 1, disease relapses and complications from extra-pancreatic involvement. Neither form affects long term survival. The treatment and follow-up guidelines continue to evolve with our increasing experience in AIP.

Association between autoimmune pancreatitis and systemic autoimmune diseases

AIM: To investigate the association between autoimmune pancreatitis (AIP) and systemic autoimmune diseases (SAIDs) by measurement of serum immunoglobulin G4 (IgG4).

METHODS: The serum level of IgG4 was measured in 61 patients with SAIDs of different types who had not yet participated in glucocorticosteroid treatment. Patients with an elevated IgG4 level were examined by abdominal ultrasonography (US) and, in some cases, by computer tomography (CT).

RESULTS: Elevated serum IgG4 levels (919 ± 996 mg/L) were detected in 17 (28%) of the 61 SAID patients. 10 patients had Sjögren’s syndrome (SS) (IgG4: 590 ± 232 mg/L), 2 of them in association with Hashimoto’s thyroiditis, and 7 patients (IgG4: 1388 ± 985.5 mg/L) had systemic lupus erythematosus (SLE). The IgG4 level in the SLE patients and that in patients with SS were not significantly different from that in AIP patients (783 ± 522 mg/L). Abdominal US and CT did not reveal any characteristic features of AIP among the SAID patients with an elevated IgG4 level.

CONCLUSION: The serum IgG4 level may be elevated in SAIDs without the presence of AIP. The determination of serum IgG4 does not seem to be suitable for the differentiation between IgG4-related diseases and SAIDs.

Histopathologic Overlap between Fibrosing Mediastinitis and IgG4-Related Disease

Fibrosing mediastinitis (FM) and IgG4-related disease (IgG4-RD) are two fibroinflammatory disorders with potentially overlapping clinical and radiological features. In this paper, we looked for histopathologic features of IgG4-RD and enumerated infiltrating IgG4-positive plasma cells within mediastinal tissue biopsies from FM patients. We identified 15 consecutive FM surgical mediastinal tissue biopsies between 1985 and 2006. All patients satisfied the clinical and radiological diagnostic criteria for FM. All patients had either serological or radiological evidence of prior histoplasmosis or granulomatous disease, respectively. Formalin-fixed paraffin-embedded tissue sections of all patients were stained for H&E, IgG, and IgG4. Three samples met the predefined diagnostic criteria for IgG4-RD. In addition, characteristic histopathologic changes of IgG4-RD in the absence of diagnostic numbers of tissue infiltrating IgG4-positive plasma cells were seen in a number of additional cases (storiform cell-rich fibrosis in 11 cases, lymphoplasmacytic infiltrate in 7 cases, and obliterative phlebitis/arteritis in 2 cases). We conclude that up to one-third of histoplasmosis or granulomatous-disease-associated FM cases demonstrate histopathological features of IgG4-RD spectrum. Whether these changes occur as the host immune response against Histoplasma or represent a manifestation of IgG4-RD remains to be determined. Studies to prospectively identify these cases and evaluate their therapeutic responses to glucocorticoids and/or other immunosuppressive agents such as rituximab are warranted.

Relationship between pancreatic and/or extrapancreatic lesions and serum IgG and IgG4 levels in IgG4-related diseases

OBJECTIVE

We aimed to investigate the relationship between the number of involved organs or regions and serum immunoglobulin G (IgG) and immunoglobulin G4 (IgG4) levels.

METHODS

The number of pancreatic and/or extrapancreatic lesions and serum IgG and IgG4 levels were examined by groups in 46 patients with IgG4-related diseases at diagnosis prior to the initiation of steroid treatment: group A (one region involved, n=7), group B (two regions involved, n=11), group C (three regions involved, n=12), group D (four regions involved, n=9) and group E (five to seven regions involved, n=7).

RESULTS

Both serum IgG and IgG4 levels increased with the number of inflamed regions. Mean serum IgG levels were 15.11, 18.65, 20.92, 23.29 and 30.98 g/L while the mean IgG4 levels were 3.99, 4.70, 4.70, 9.86 and 16.49 g/L in group A, B, C, D and E, respectively. Regression analysis also suggested that IgG4 was positively correlated with the number of regions involved. Additionally, serum IgG4 was higher in patients with multiple lesions when accompanied by sclerosing sialadenitis.

CONCLUSION

Patients having IgG4-related disease with high serum IgG and IgG4 levels should be systematically examined for involved lesions.

Clinical differences between mass-forming autoimmune pancreatitis and pancreatic cancer

OBJECTIVE

Autoimmune pancreatitis (AIP) needs to be differentiated from pancreatic cancer (PC). We aimed to clarify the findings specific for AIP by comparing the clinical differences between mass-forming AIP and PC.

MATERIAL AND METHODS

We retrospectively compared 36 patients with mass-forming AIP and 60 with PC without metastasis regarding clinical, imaging, serological, histological differences and other organ involvement (OOI). We evaluated the sensitivity, specificity and accuracy of these findings for the differential diagnosis between AIP and PC.

RESULTS

The findings 100% specific for AIP were a capsule-like rim on computed tomography (CT), skipped lesion of main pancreatic duct (MPD) on endoscopic retrograde pancreatography (ERP) or magnetic resonance cholangiopancreatography (MRCP), γ-globulin > 2 g/dl, OOI (extrapancreatic biliary stricture, salivary gland swelling and retroperitoneal fibrosis) and ruling out PC by histopathological findings of endoscopic ultrasonography-guided fine-needle aspiration. The findings over 90% specific were IgG4 > 280 mg/dl (98%), IgG > 1800 mg/dl (97%), maximal diameter of upstream MPD < 5 mm on MRCP (95%) and IgG4 > 135 mg/dl (94%), respectively.

CONCLUSIONS

Clinical, imaging, serological, histological findings and OOI differed between mass-forming AIP and PC. Capsule-like rim on CT, skipped lesion of MPD on ERP or MRCP, IgG4 > 280 mg/dl, and OOI were highly specific findings for AIP. These findings are useful in the differential diagnosis of mass-forming AIP from PC.

Serum immunoglobulin G4 associated with number and distribution of extrapancreatic lesions in type 1 autoimmune pancreatitis patients

BACKGROUND AND AIM

Type 1 autoimmune pancreatitis (AIP) is characterized by the increase of serum immunoglobulin (Ig)G4 and abundant IgG4 plasma cell infiltration in the pancreas and various extrapancreatic lesions (EPL), which are proposed as IgG4-related disease. We assessed the correlation between serum IgG4 and the number of EPL, and the association between serum IgG4 and the distribution of EPL in type 1 AIP patients.

METHODS

Serum IgG4 was measured in 35 type 1 AIP patients and 71 non-AIP patients. The clinical characteristics and distribution of eight EPL were determined in 35 type 1 AIP patients.

RESULTS

Serum IgG4 in type 1 AIP was significantly higher than in non-AIP (P < 0.001). A total of 33 patients had EPL among 35 patients with type 1 AIP (94.3%). There was a significant correlation between serum IgG4 and the number of EPL (ρ = 0.75, P < 0.001). Further, to assess the association between serum IgG4 and the distribution of EPL, type 1 AIP patients were divided into two groups: as abdominal localized EPL and systemic EPL. Both serum IgG4 and total numbers of EPL in systemic EPL were remarkably higher than those in abdominal localized EPL. Serum IgG4 cut-off value was 346 mg/dL to distinguish between abdominal localized EPL and systemic EPL according to the receiver-operator characteristic curve data.

CONCLUSIONS

Our findings indicated that serum IgG4 was useful in both the diagnosis of type 1 AIP and the detection of systemic EPL. Our finding may help the concept and diagnostic criteria of IgG4-related disease with type 1 AIP.

IgG4-related sclerosing disease: autoimmune pancreatitis and extrapancreatic manifestations

Autoimmune pancreatitis is the pancreatic manifestation of IgG4-related sclerosing disease, which recently was recognized as a distinct disease entity. Numerous extrapancreatic organs, such as the bile ducts, gallbladder, kidneys, retroperitoneum, thyroid, salivary glands, lung, mediastinum, lymph nodes, and prostate may be involved, either synchronously or metachronously. Most cases of autoimmune pancreatitis are associated with elevated serum IgG4 levels; extensive IgG4-positive plasma cells; and infiltration of lymphocytes into various organs, which leads to fibrosis. There are several established diagnostic criteria systems that are used to diagnose autoimmune pancreatitis and that rely on a combination of imaging findings of the pancreas and other organs, serologic findings, pancreatic histologic findings, and response to corticosteroid therapy. It is important to recognize multiorgan involvement of IgG4-related sclerosing disease and be familiar with its clinical and imaging features because it demonstrates a favorable response to treatment.

A case of IgG4-related sclerosing cholangitis overlapped with primary biliary cirrhosis

IgG4-related sclerosing cholangitis (IgG4-SC) and primary biliary cirrhosis (PBC) can both cause liver dysfunction. While IgG4-SC is associated with IgG4-related diseases such as autoimmune pancreatitis, PBC is associated with various autoimmune diseases. However, there is only one case report of an association between IgG4-SC and PBC, and this association has not been elucidated further. The treatments for these two diseases are different, i.e., corticosteroid treatment is performed for IgG4-SC and ursodeoxycholic acid is given for PBC. We report a case of IgG4-SC overlapping with PBC in a 45-year-old man who was successfully treated by combination therapy with prednisolone and ursodeoxycholic acid.

Diagnostic criteria for IgG4-related sclerosing cholangitis based on cholangiographic classification

BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-SC) needs to be differentiated from pancreatic cancer (PCa), primary sclerosing cholangitis (PSC), and cholangiocarcinoma (CC). We attempted to establish diagnostic criteria for IgG4-SC based on cholangiographic classification by comparison with several diagnostic modalities.

METHODS

We classified 62 IgG4-SC patients into three groups on the basis of cholangiographic findings to allow differentiation from PCa, PSC, and CC: Group A IgG4-SC showed features similar to PCa (Type 1, n = 32), Group B showed similarity to PSC (Type 2, n = 15), and Group C showed similarity to CC (Type 3, 4, n = 15). Thirty-five patients with PCa, 40 with PSC, and 32 CC were enrolled as controls. We retrospectively compared the clinical, imaging, serological, and histopathological features and involvement of other organs between Group A and PCa, Group B and PSC, and Group C and CC.

RESULTS

Association with autoimmune pancreatitis (AIP) (P < 0.001) and involvements with other organs (specificity 100%) were common useful diagnostic parameters in all three IgG4-SC groups. A high serum IgG4 level was a useful parameter in Groups A and B (P < 0.001). Discriminant analysis of cholangiograms (P < 0.001), liver biopsy (specificity 100%), and exclusion of inflammatory bowel disease (specificity 100%) were useful parameters in Group B. Intraductal ultrasonography findings (P < 0.001) and exclusion of malignancy by bile duct biopsy (specificity 100%) were useful parameters in Group C. We established diagnostic criteria for IgG4-SC (sensitivity 100%, specificity 96.3%) by incorporating parameters that showed P < 0.001 or 100% specificity.

CONCLUSIONS

Diagnostic criteria for IgG4-SC based on cholangiographic classification are useful for distinguishing it from PCa, PSC, and CC.

A case of autoimmune pancreatitis showing narrowing of the main pancreatic duct after cessation of steroid therapy in the clinical course

Autoimmune pancreatitis (AIP) is characterized by irregular narrowing of the main pancreatic duct (MPD), and narrowing of the MPD is an essential criterion for the diagnosis of focal/segmental AIP according to the Japanese diagnostic criteria 2011. We report a 55-year-old man in whom magnetic resonance imaging showed two masses in the pancreatic head and tail and whose pancreatogram was normal at first. However, the two masses changed into diffuse swelling of the pancreas, and diffuse narrowing of the MPD appeared after the cessation of steroid therapy. Finally, we could diagnose this patient as having AIP according to the Japanese diagnostic criteria.

Benign biliary strictures: a current comprehensive clinical and imaging review

OBJECTIVE

There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities.

CONCLUSION

Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.