High-rate pulmonary involvement in autoimmune pancreatitis

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Clinical presentation and organ-based outcomes of Multifocal fibrosclerosis: A systematic review

Objectives

Multifocal fibrosclerosis is a rare disorder causing progressive fibrosis of multiple organ systems. Existing data on the disease show that there are multiple manifestations of the disease, with different outcomes. However, quantitative data are scarce, prompting the need for our investigation.

Method

A comprehensive systematic review was performed from inception to November 16, 2022, with the restriction of English language, not including review articles. Article screening and extraction was performed independently, and shortlisted articles were assessed for bias. Analysis was performed using SPSS Version 25 (IBM® SPSS® Statistics; Chicago, IL, USA). Data were presented as frequencies and percentages, with a confidence interval of 95%.

Result

This review included 134 patients, with 78 (58.2%) males. Mean age was 53.6 years and included two pediatric patients. The most common comorbidity was diabetes (9.7%). Prevalent presenting symptoms included pain (47.8%) and swelling (35.1%). A mean of 2.51 organs or anatomical sites was affected, retroperitoneum (64.2%) being most affected. The pancreas (30.0%) and digestive system (47.0%) were the organs/organ systems most affected. Patients had favorable outcomes in 79.1% of cases, 87.3% had no relapse, and 91.8% of patients survived the condition.

Conclusion

The findings in this study provide a quantitative measurement of the demographics, presentations, organ manifestations, and outcomes of multifocal fibrosclerosis. We found the disease to be prevalent in males in Japan or the United States, with the abdomen and its organs being commonly involved.

Clinicopathological Characteristics of Primary Pulmonary Hodgkin Lymphoma (PPHL): Two Institutional Experiences with Comprehensive Literature Review of 115 PPHL Cases

Primary pulmonary Hodgkin lymphoma (PPHL) is an extremely rare condition. Its clinicopathological characteristics remain unclear because of the limited number of patients with PPHL. The aim of this study was to comprehensively analyze the clinicopathological characteristics of PPHL. We reviewed the electronic medical records and pathology slides of our 10 PPHL patients. The female-to-male ratio was 6:4, and the mean age was 41 years. Although three patients had no symptoms, seven had localized or generalized symptoms, including cough, sputum, chest discomfort/pain, and weight loss. Some cases had not been diagnosed as PPHL in the initial needle biopsy. Four patients underwent surgical resection. With chemotherapy, eight patients achieved complete remission. We also conducted a thorough literature review on 105 previously reported PPHL cases. Among a total of 115 PPHL cases, the most common subtype was nodular sclerosis (37.4%). More than half of the cases (55%) were clinically suspected as infectious pneumonia. Of 61 patients whose biopsies were available, 27 (44.3%) were diagnosed correctly as Hodgkin lymphoma, whereas the misdiagnoses included tuberculosis, Langerhans cell histiocytosis, solitary fibrous tumor, and adenocarcinoma. We demonstrated that PPHL represents a diagnostic challenge on small biopsies. Recognizing that this rare tumor can mimic infectious and inflammatory diseases as well as malignancies is important because the accurate diagnosis of PPHL is essential for adequate clinical management.

Amendment of the Japanese consensus guidelines for autoimmune pancreatitis, 2020

In response to the latest knowledge and the amendment of the Japanese diagnostic criteria for autoimmune pancreatitis (AIP) in 2018, the Japanese consensus guidelines for managing AIP in 2013 were required to be revised. Three committees [the professional committee for developing clinical questions (CQs) and statements by Japanese specialists; the expert panelist committee for rating statements by the modified Delphi method; and the evaluating committee of moderators] were organized. Twenty specialists in AIP extracted the specific clinical statements from a total of 5218 articles (1963-2019) from a search in PubMed and the Cochrane Library. The professional committee made 14, 9, 5, and 11 CQs and statements for the current concept and diagnosis, extra-pancreatic lesions, differential diagnosis, and treatment, respectively. The expert panelists regarded the statements as valid after a two-round modified Delphi approach with individually rating these clinical statements, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. After evaluation by the moderators, the amendment of the Japanese consensus guidelines for AIP has been proposed in 2020.

Thoracic paravertebral involvement in patients with IgG4-related disease: CT and MR imaging findings

OBJECTIVES

To retrospectively evaluate CT and magnetic resonance (MR) imaging thoracic paravertebral findings at baseline and follow-up in patients with IgG4-related disease.

METHODS

The study consisted of 36 patients with IgG4-related disease involving thoracic paravertebral regions (32 men and four women; mean age, 58 years; range, 25-78 years). A total of 36 patients underwent CT or MR imaging at baseline; 20 patients underwent follow-up. CT and MR images were reviewed and analysed in consensus by two radiologists for the various features of thoracic paravertebral lesions.

RESULTS

All lesions were located around two or more thoracic vertebrae, particularly the lower thoracic vertebrae (n = 36). The right side of vertebrae was predominantly affected in all cases (n = 36). Radiologically, IgG4-related thoracic paravertebral lesions were categorized into three types: solitary or multiple saddle-like masses type (32 patients); multiple nodules type (three patients); and invasively irregular mass type (three patients). All the types showed soft-tissue density on CT images, isointense on T1- and T2-weighted images, and homogeneous enhancement with penetration of small arteries in the lesions on contrast-enhanced CT and MR images. Steroid therapy administered to 20 patients dramatically diminished the mean maximum thickness in 18 patients. One patient with T7-12 vertebrae involved improved after steroid therapy.

CONCLUSION

IgG4-related paravertebral lesions occur mainly around the right side of the lower thoracic vertebrae and manifest as three major patterns of CT and MR imaging findings. Recognition of these diagnostic features will assist in the diagnosis and treatment of IgG4-related disease.

Imaging diagnosis of autoimmune pancreatitis: computed tomography and magnetic resonance imaging

Autoimmune pancreatitis (AIP) is a pancreatic phenotype of IgG4-related systemic disease. Since its first description in the literature, characteristic imaging features have gradually become known to many clinicians encompassing various specialties in the past quarter century. CT and MRI have been the workhorses for imaging diagnosis of AIP. Typical features include sausage-like swelling of the focal or entire pancreas, duct-penetrating sign, a capsule-like rim of the affected lesions, and homogeneous delayed enhancement or enhanced duct sign after contrast administration, as well as characteristic combined findings reflecting coexisting pathologies in the other organs as a systemic disease. In this review, recent and future developments in CT and MRI that may help diagnose AIP are discussed, including restricted diffusion and perfusion and increased elasticity measured using MR.

Features of IgG4-related lung disease on 18F-FDG PET/computed tomography imaging

OBJECTIVES

The aim of the study was to summarize the features of immunoglobulin G4-related lung disease (IgG4-RLD) on fluorine 18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT).

METHODS

In this retrospective case series, 12 consecutive patients (9 men and 3 women, mean age 55.4 ± 13.7 years) with IgG4-RLD were included. The clinicopathological information and features of F-FDG PET/CT imaging were analyzed.

RESULTS

Six (50%) patients had pulmonary involvement alone and six (50%) patients had extrapulmonary involvement with intense F-FDG uptake. Pulmonary manifestations included mass (25%, 3/12), solid nodule (solitary 25%, 3/12; multiple 50%, 6/12), multiple ground-glass opacities (GGOs) (50%, 6/12), thickening of alveolar interstitium (50%, 6/12), and thickening of bronchovascular bundle (33.3%, 4/12). The maximum standardized uptake value (SUVmax) of the solid nodules and masses, multiple GGOs, bronchovascular bundle and the thickening of septa was 4.0 ± 2.5, 2.3 ± 1.8, 1.4 ± 0.6, and 0.9 ± 0.5, respectively. The SUVmax statistically significant linear association with the diameter of masses or solid nodules (P value = 0.03), but no significant inverse linear association (P value = 0.06) with the concentration of serum IgG4 concentration.

CONCLUSIONS

The image patterns of IgG4-RLD on F-FDG PET/CT are varying. Multiple pulmonary manifestations or multiple organ involvement, especially in combination with elevated levels of serum IgG and IgG4, may help to make the diagnosis. A potential major application of PET-CT would be evaluation of response to treatment, and the impact of PET/CT on IgG4-RLD management is worth investigating further in the future.

A case of IgG4-related anterior mediastinal sclerosing disease coexisting with autoimmune pancreatitis

Background

IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory condition that predominantly involves exocrine organs. Concerning its thoracic presentation, it often manifests as interstitial lung disease or fibrosing mediastinitis. It is very rare for IgG4-RD to form a well-defined mass in the anterior mediastinum, mimicking an encapsulated thymoma.

Case presentation

An 82-year-old man with autoimmune pancreatitis under treatment with oral corticosteroids was found to have peripancreatic lymphadenopathy on computed tomography. Subsequent positron emission tomography revealed abnormal uptake (maximal value 3.6) by a thymic mass as well as the peripancreatic lymph nodes. Exacerbation of IgG4-RD was suspected, and we increased the oral steroid dosage. As a result, the peripancreatic lymph nodes, and the anterior mediastinal mass, decreased in size. The thymic mass was suspected to be an encapsulated thymoma because of its lobulated shape, degree of fluorodeoxyglucose accumulation, and response to steroids, and the patient was referred to our department. The serum anti-acetylcholine receptor antibody test was negative. A thoracoscopic tumor resection was performed as diagnostic therapy. Histopathological analysis revealed dense lymphoplasmacytic infiltration with sclerotic stroma within the tumor. Immunohistochemical analysis revealed abundant IgG4-positive plasma cell infiltrates and over 50% IgG4/IgG-positive plasma cells. We did not see either keratin-positive thymocytes or terminal deoxynucleotidyl transferase-positive lymphocytes. Furthermore, deviation in the kappa chain and lambda chain-positive plasma cells was not noted. Accordingly, IgG4-related sclerosing disease was diagnosed.

Conclusions

IgG4-related sclerosing masses in the anterior mediastinum are very rare, and the effect of tumor resection on prognosis remains unclear. IgG4-RD had potentially been categorized as Castleman’s disease.

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.

MR Imaging of Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is characterized by autoimmune inflammatory destruction of the pancreatic tissue. Imaging plays an essential role in the diagnosis. AIP type 1 is the pancreatic manifestation of immunoglobulin G4 (IgG4)-related disease and is associated with IgG4-positive plasma cell infiltration and fibrosis of multiple organ systems. Type 2 is a related disease with pancreatic inflammation with or without concurrent inflammatory bowel disease. The authors demonstrate the imaging findings that are associated with the pancreatic and extra-pancreatic manifestations of AIP. They emphasize the common MR imaging and magnetic resonance cholangiopancreatography findings to help make the diagnosis of AIP.

IgG4-related Disease - A Systemic Disease that Deserves Attention Regardless of One's Subspecialty

IgG4-related disease (IgG4-RD) is an inflammatory condition characterized by a high serum IgG4 concentration and the abundant infiltration of lymphocytes and IgG4-positive plasma cells in the tissue, as well as spatial (diverse clinical manifestations) and temporal (the possibility of recurrence) multiplicities. Since the initial documentation of IgG4-related disease in patients with autoimmune pancreatitis in 2001, a growing body of evidence has been accumulating to suggest that various-virtually all-organs can be affected by IgG4-RD. In general, steroid therapy is effective and is considered to be the first-line treatment for IgG4-RD. The precise mechanism underlying this systemic disorder has remained unknown. Considering that IgG4-RD was specified as being an intractable disease in 2015, further studies are needed to clarify whether IgG4-RD is indeed a distinct disease entity or a complex of disorders of different etiologies and clinical conditions.

A case of immunoglobulin G4-related respiratory disease with multiple lung cysts: A case report

A 48-year-old man was admitted for evaluation of abnormal shadows on chest radiograph. Chest computed tomography (CT) showed cysts, nodules, and cervical and axillary lymphadenopathies. Elevated serum levels of IgG4 and interleukin (IL)-6 suggested IgG4-related disease (IgG4-RD) or multicentric Castleman's disease (MCD). Histologic findings of the cervical lymph node and right lung S⁶ biopsies revealed numerous IgG4-positive plasma cells. Although CT findings of the lungs were atypical for IgG4-RD, consistent histologic findings, clinical symptoms, and laboratory data made us conclude IgG4-RD. Because histologic findings of IgG4-RD and MCD have similarities, differentiating between the two diseases should consider the clinical presentation.

Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a rare, distinct and increasingly recognized form of pancreatitis which has autoimmune features. The international consensus diagnostic criteria (ICDC) for AIP recently described two subtypes; type 1[lymphoplasmacytic sclerosing pancreatitis (LPSP)] and type 2 [idiopathic duct-centric pancreatitis (IDCP) or AIP with granulocytic epithelial lesion (GEL)]. Type 1 is the more common form of the disease worldwide and current understanding suggests that it is a pancreatic manifestation of immunoglobulin G4-related disease (IgG4-RD). In contrast, type 2 AIP is a pancreas-specific disease not associated with IgG4 and mostly without the overt extra-pancreatic organ involvement seen in type 1. The pathogenesis of AIP is not completely understood and its clinical presentation is non-specific. It shares overlapping features with more sinister pathologies such as cancer of the pancreas, which continues to pose a diagnostic challenge for clinicians. The diagnostic criteria requires a variable combination of histopathological, imaging and serological features in the presence of typical extrapancreatic lesions and a predictable response to steroids.

Outcome of Long-term Maintenance Steroid Therapy Cessation in Patients With Autoimmune Pancreatitis: A Prospective Study

OBJECTIVE

To predict the duration of steroid maintenance therapy required to achieve good prognosis in patients with autoimmune pancreatitis.

PATIENTS AND METHODS

The study sample comprised 21 patients with autoimmune pancreatitis who met the following criteria: (1) they received steroid therapy (ST) for at least 3 years without clinical relapse; and (2) immunoglobulin (Ig) G<1600 mg/dL was observed in the past year with a prednisolone maintenance dose ≤5 mg. All patients could be diagnosed with international consensus diagnostic criteria. Patients were prospectively followed up after tapering and cessation of steroids. Clinical relapse was defined as the need to resume ST. Serological relapse was defined as having an IgG level of >1600 mg/dL.

RESULTS

During the 43-month (range, 19 to 48 mo) follow-up period, clinical relapse occurred in 10 patients: pancreatic lesion in 4; coronary lesion in 2; submandibular lesion in 1; both pulmonary and renal lesions in 1; pulmonary, retroperitoneal, and submandibular lesions in 1; and bronchial asthma in 1. Serological relapse was observed in 12 patients. Although clinical and serological relapse occurred concomitantly in 3 patients, serological relapse preceded clinical relapse in 4 patients. Five patients experienced serological relapse alone, and no clinical or serological relapse occurred in 6 patients. According to Cox proportional hazard analysis, the duration of ST before tapering was a significant predictive parameter (hazard ratio, 0.969/month; 95% confidence interval, 0.940-0.998; P=0.038).

CONCLUSIONS

ST cessation resulted in a high rate of clinical relapses, even in patients with long-term maintenance therapy. Therefore, it appears desirable to continue steroid maintenance therapy for a period >3 years to prevent relapse.

IgG4 Related Lung Disease

IgG4 related disease is a poorly understood immune mediated condition. Lung involvement is rare and difficult to diagnose and can mimic primary lung malignancy on imaging. A patient who was found to have an incidental lung lesion with risk factors for primary pulmonary malignancy is reported.

IgG4-Related Lung Disease Associated with Usual Interstitial Pneumonia

We report a case of immunoglobulin(Ig)G4-related disease with the radiologic and histopathological manifestations resembling usual interstitial pneumonia (UIP). The patient was a 62-year-old man who presented with progressive dyspnea of insidious onset. High resolution computed tomography of the chest showed lower-lobe predominant peripheral reticulation and traction bronchiectasis but no honeycomb change. Microscopic examination of the surgical lung biopsy showed characteristic features of UIP including architectural distortion by fibrosis with peripheral and paraseptal accentuation, scattered fibroblast foci and microscopic honeycomb change. In addition there were prominent multifocal lymphoplasmacytic infiltrates with a marked increase of IgG4-positive plasma cells (79 per high power field in hot spots) and high IgG4/IgG ratio (up to 67%). The serum IgG4 level was elevated at 760 mg/dl (reference range 9-89), with normal levels for the other IgG subclasses and negative serologic markers for autoimmune diseases. The patient’s symptoms improved significantly with oral corticosteroid treatment.

Clinical review of pulmonary manifestations of IgG4-related disease

IgG4-related disease (IgG4-RD) is a recently recognized systemic disease characterized by tumefactive lesions in various organ systems. The list of organs that can be involved continues to expand, and recently computed tomography (CT) descriptions of the pulmonary lesions found in the disease have been described. The clinical symptoms are nonspecific and may include cough, dyspnea, chest pain, and fever. The appropriate clinical presentation along with elevated serum IgG4 concentrations and pathologic evidence of lymphoplasmacytic infiltrates with abundant IgG4-positive plasma cells and storiform fibrosis is consistent with the disease. Steroids are used to treat this disease in addition to immunosupressives such as cyclosporine or rituxumab for steroid refractory disease. The pulmonary manifestations and imaging features can often mimic malignancy, and as such knowledge of the diagnostic, clinicopathologic, and radiographic features of the disease is required in order to provide appropriate diagnostic workup and treatment.

Serum immunoglobulin G4 level is a poor predictor of immunoglobulin G4-related disease

OBJECTIVES

Immunoglobulin G4-related disease (IgG4-RD) is characterized by elevation in serum IgG4 levels, typical multiorgan involvement and dramatic response to steroid therapy. We determined the predictive value of an elevated serum IgG4 for the diagnosis of IgG4-RD. We also sought to identify novel conditions, which have characteristic features of IgG4-RD.

METHODS

We identified all Mayo Clinic Rochester patients with serum IgG4 levels measured between January 2008 and December 2011 (n = 6014). Those with elevated serum IgG4 levels (reference range, 121-140 mg/dL) were included in the analysis and were classified as "definite," "probable," or "no" IgG4-RD.

RESULTS

Serum IgG4 levels were elevated in 390 subjects (6.5%) of whom only 39 (10%) had IgG4-RD (29 "definite," 10 "probable"). The positive predictive value of an elevated serum IgG4 for IgG4-RD was poor (10%). Subjects with IgG4-RD differed from those without IgG4-RD in mean age (59.6 ± 15.2 vs 54.4 ± 18.3 years, P < 0.05), % males (90% vs 58%, P < 0.05), mean serum IgG4 level (437 ± 471 vs 223 ± 194 mg/dL, P < 0.05), and presence of chronic rhinosinusitis (7/39 vs 29/351, P = 0.05).

CONCLUSIONS

Elevated serum IgG4 levels are not specific for IgG4-RD and are likely to be a false-positive. Chronic rhinosinusitis is likely an as yet underrecognized manifestation of IgG4-RD.

Unusual Multiorgan Immunoglobulin G4 (IgG4) Inflammation: Autoimmune Pancreatitis, Mikulicz Syndrome, and IgG4 Mastitis

Autoimmune pancreatitis (AIP) type 1 is commonly associated with simultaneous involvement of extrapancreatic organs. Sclerosing cholangitis, sialadenitis, retroperitoneal fibrosis, Sjögren syndrome, and other extrapancreatic lesions are often observed concurrently with AIP. High levels of immunoglobulin G4 (IgG4) in the blood serum and affected tissues are typical of this diagnostic entity. We describe a case report of a 58-year-old female with findings of AIP (according to Asian criteria), IgG4-positive mastitis, and histologically verified Mikulicz syndrome. The effect of corticoid therapy supported the diagnosis of AIP and simultaneously led to the eradication of recurrent mastitis. To the best of our knowledge, this is the first reported case of concurrent findings of AIP and IgG4 mastitis. Our case report supports the concept of systemic IgG4 syndrome with multisystem involvement. Timely diagnosis and appropriate therapy can be effective in a high percentage of patients.

Comparison between sarcoidosis and IgG4-related disease by whole-body 67Ga scintigraphy

PURPOSE

The aim of this study was to compare uptake lesions in sarcoidosis and IgG4-related disease through gallium-67 ((67)Ga) scintigraphy to differentiate between the two diseases.

MATERIALS AND METHODS

Whole-body (67)Ga scintigraphy findings of 27 patients with sarcoidosis and 16 with IgG4-related disease were reviewed between 2005 and 2011 at our hospital.

RESULTS

In the case of patients with sarcoidosis, significant accumulation of (67)Ga was observed in the lacrimal gland in the case of 26 patients (96%), in mediastinal lymph nodes (LNs) in 23 (85%), in pulmonary hilar LNs in 21 (78%), in the parotid gland in 10 (38%), in supraclavicular LNs in eight (30%), in muscles in seven (26%), in the lung in five (18%), in inguinal LNs in four (15%), in submandibular LNs in two (7%), and in the heart, spleen, kidney and para-aorta in one patient (4%). In patients with IgG4-related disease, abnormal uptake was detected in the pulmonary hilar LNs in 12 patients (75%), in the lacrimal gland in 10 (62%), in the pancreas in 10 (62%), in the parotid gland in six (37%), in the submandibular gland in six (37%), in the para-aorta in three (19%), in the lung in three (19%), in mediastinal LNs in two (12%), and in the kidney in the case of two patients (12%). Asymmetrical accumulation in the submandibular gland was observed in three of six patients (50%) with IgG4-related disease and in none of the two patients (0%) with sarcoidosis. Significant differences were observed in the uptake ratio of the lacrimal gland, the submandibular gland, supraclavicular LNs, mediastinal LNs, pancreas, and muscle between the two groups (P<0.05).

CONCLUSION

(67)Ga scintigraphy was useful in differentiating between the two diseases. Uptake in mediastinal LNs, in supraclavicular LNs, and in the muscle was specific to sarcoidosis, whereas uptake in the pancreas and in the submandibular gland indicated IgG4-related disease.

Thoracoscopic resection for a pulmonary nodule with the infiltrate of IgG4-positive plasma cells

This report describes a rare case of IgG4-related lung disease that was difficult to distinguish from lung cancer. CT revealed a well-demarcated round tumor in S10 of the right lung of a 56-year-old man suspected of having lung cancer. PET revealed high fluorodeoxyglucose uptake with a maximum standardized uptake value of 14.0. Because primary lung cancer was strongly suspected, lower lobectomy was performed via the thoracoscopic approach without mini-thoracotomy. Histopathology showed lymphoplasmacytic infiltration. Immunostaining revealed numerous IgG4-positive plasma cells diffusely infiltrating the tumor. Serum IgG4 levels increased, thereby confirming the diagnosis of IgG4-related lung disease.

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.

Long-term prognosis of autoimmune pancreatitis in terms of glucose tolerance

OBJECTIVE

Glucose intolerance is often observed in autoimmune pancreatitis (AIP), although its long-term prognosis after steroid treatment (ST) is still unclear.

METHODS

A total of 47 patients with AIP were enrolled. On the basis of the change in hemoglobin A1c (HbA1c) and the use of diabetic medication, prognosis was classified into 3 categories, namely, "improved," "aggravated," and "unchanged." The relation between the result of an initial glucagon tolerance test (ΔCPR) and the later use of insulin during maintenance ST was examined in 20 patients. The transitions of homeostasis model assessment β cell and insulin resistance (HOMA-β and HOMA-R) were analyzed in 16 patients.

RESULTS

Glucose tolerance was improved in 6 patients (13%), aggravated in 9 patients (19%), and unchanged in 32 patients (68%). All patients with ΔCPR less than 0.6 ng/mL were obliged to use insulin even after long-term observation, whereas all patients with ΔCPR more than 1.0 ng/mL were free from insulin therapy. Moreover, HOMA-β showed significant improvement after ST (43.9% → 56.0% in median, P = 0.030), and HOMA-R showed significant aggravation (1.30 → 1.78, P = 0.039).

CONCLUSIONS

Glucose tolerance that is too severely damaged may not recover fully even after ST. Thus, ST should be performed to preserve insulin secretion at the early stage of AIP.

Immunoglobulin G4-related cholangitis: a variant of IgG4-related systemic disease

IgG4-related sclerosing cholangitis as part of IgG4 systemic-related diseases is commonly associated with autoimmune pancreatitis. Major clinical manifestations of IgG4-related sclerosing diseases are apparent in the organs in which tissue fibrosis with obstructive phlebitis is pathologically induced. IgG4-related sclerosing cholangitis is included within the heterogeneous group of 'sclerosing cholangitis'. Sclerosing cholangitis may be associated with choledocholithiasis, infection or biliary malignancies. Sclerosing cholangitis of unknown etiology is called primary sclerosing cholangitis (PSC). Conservative therapy of PSC is usually unsuccessful, the disease involves extra- and/or intrahepatic biliary tree, and the end point of this disease is liver cirrhosis. Typically, PSC is identified at the age of 30 to 40 years, and the disease is frequently associated with inflammatory bowel diseases. On the other hand, IgG4-related sclerosing cholangitis is not associated with inflammatory bowel diseases. In patients with IgG4-related sclerosing cholangitis, a first symptom can be obstructive jaundice, whereas obstructive jaundice is rarely present in PSC. Clinically, patients with IgG4-related sclerosing cholangitis are older at diagnosis compared to patients with PSC. A typical diagnostic feature of IgG4-related sclerosing cholangitis is elevation of serum immunoglobulin G4. In patients with IgG4-related sclerosing cholangitis, response to steroid therapy is high; in patients with PSC corticosteroid therapy is unsuccessful. Histochemically abundant infiltration of IgG4-positive plasma cells is detected in the biliary duct wall. Histologically, we can identify dense lymphoplasmacytic infiltration of the bile duct wall, transmural fibrosis, lymphoplasmacytic infiltration and fibrosis in the periportal area of the liver - a typically obliterative phlebitis. The biliary epithelium is usually intact in contrast to PSC, where mucosal erosion is often present. Steroids are the first-choice therapy of IgG4-related sclerosing cholangitis. In the literature, cholangiocarcinoma in patients with IgG4- related sclerosing cholangitis was not described, whereas cholangiocarcinoma develops in up to 10-30% of patients with PSC.

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.

A case of IgG4-related pulmonary disease with rapid improvement

We report a 72-year-old man with respiratory involvement of immunoglobulin G4 (IgG4)-related disease, who developed dry cough and shortness of breath on effort. The chest computed tomography scan image showed massive and diffuse ground-glass opacity, interlobular thickening, and bronchial wall thickening. The infiltration of IgG4-positive plasma cells in the transbronchial lung biopsy and high serum IgG4 concentrations were found. The patient was treated with 0.6 mg/kg oral prednisolone and showed rapid improvement. This is a case of IgG4-related disease in which the only complication was respiratory involvement.

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.

Respiratory involvement in IgG4-related Mikulicz's disease

'Immunoglobulin G4 (IgG4)-related disease' is a new clinical concept of multi-organ diseases, with Mikulicz's disease (MD) being a clinical phenotype of IgG4-related disease. To clarify the clinical characteristics of respiratory involvement associated with IgG4-related MD, we retrospectively assessed 25 patients with MD, 11 (44%) of whom had allergic symptoms, and 7 (28%) of whom complained of respiratory problems. Thirteen patients (52%) presented with pulmonary and/or mediastinal lesions (P-MD) on chest computed tomography (CT), and 11 (44%) had lesions limited to the lacrimal and/or salivary glands (L-MD). Mean serum total protein, IgG, and IgG4 concentrations were significantly higher and CH50 was significantly lower in the P-MD than in the L-MD group. Immune complex was present only in the P-MD group. Chest CT images showed bronchial wall thickening, consolidation, nodule(s), interlobular thickening, ground glass opacity, pleural thickening/effusion, and mediastinal lymphadenopathy. Five of seven patients who underwent histological examination of the lungs had abundant IgG4-positive plasma cell infiltrates (IgG4/IgG-positive plasma cells >40%), but the other two did not. These findings suggest that respiratory lesions are not rare in patients with IgG4-related MD, and that they present with various manifestations. IgG4-related MD should be differentiated from similar diseases, such as sarcoidosis, bronchial asthma, Sjögren's syndrome, and malignant lymphoma.

Infraorbital nerve swelling associated with autoimmune pancreatitis

PURPOSE

The aim of our study was to examine the relation between autoimmune pancreatitis (AIP) and infraorbital nerve swelling.

MATERIALS AND METHODS

A total of 11 AIP patients underwent magnetic resonance imaging (MRI) examination of the head and neck region. The infraorbital nerve thicknesses were measured on coronal images and compared with those of a control group. We also examined whether the infraorbital nerve thicknesses were altered from before to after steroid therapy in nine patients who underwent MRI examination after such therapy.

RESULTS

The mean thicknesses were 3.8 ± 2.0 mm in the AIP group and 2.6 ± 0.5 mm in the control group (P < 0.05). The nerve thicknesses were >5 mm in 5 of 11 patients (45%) in the AIP group, and <5 mm in all of the control group. Among the nine patients who underwent MRI examination after steroid therapy, three had shown nerve swelling before steroid therapy; the therapy diminished the swelling in all three patients.

CONCLUSION

Infraorbital nerve swelling was observed more frequently in AIP patients than in patients without a history of AIP. Therefore, such swelling seems to be an extrapancreatic lesion of AIP.

Deposition of complement C3c, immunoglobulin (Ig)G4 and IgG at the basement membrane of pancreatic ducts and acini in autoimmune pancreatitis

AIMS

Autoimmune pancreatitis (AIP) is a type of pancreatitis whose immunopathogenesis is still unknown. It has been reported that renal biopsy specimens from patients diagnosed with both AIP and tubulointerstitial nephritis reveal deposits containing complement C3, immunoglobulin (Ig)G and IgG4 at the tubular basement membranes (BMs). The aim was to investigate the deposition of complement and immunoglobulins in pancreatic tissue from AIP patients compared to non-AIP patients.

METHODS

Double immunofluorescence microscopy for C3c, IgG4 and IgG together with CK7, trypsin, collagen IV, CD31 and CD79a, as well as immunofluorescence microscopy for C1q, IgA and IgM, were performed on frozen pancreatic tissue from AIP and alcoholic chronic pancreatitis (ACP) patients.

RESULTS

In AIP patients, complement C3c, IgG4 and IgG were deposited at the collagen IV-positive BMs of pancreatic and bile ducts and of acini. In a minority of the ACP patients, weak C3c-positive BM deposits were detected, but no IgG4- or IgG-positive BM deposits were present.

CONCLUSION

The deposition of C3c, IgG4 and IgG at the BM of small- and medium-sized ducts and acini of the pancreas is characteristic of AIP. This suggests that immune complex-mediated destruction of ducts and acini play a role in the pathogenesis of AIP.

Clinical analysis of high serum IgE in autoimmune pancreatitis

AIM: To clarify the clinical significance of high serum IgE in autoimmune pancreatitis (AIP).

METHODS: Forty-two AIP patients, whose IgE was measured before steroid treatment, were analyzed. To evaluate the relationship between IgE levels and the disease activity of AIP, we examined (1) Frequency of high IgE (> 170 IU/mL) and concomitant allergic diseases requiring treatment; (2) Correlations between IgG, IgG4, and IgE; (3) Relationship between the presence of extrapancreatic lesions and IgE; (4) Relationship between clinical relapse and IgE in patients treated with steroids, and (5) Transition of IgE before and after steroid treatment.

RESULTS: IgE was elevated in 36/42 (86%) patients. Concomitant allergic disease was observed in seven patients (allergic rhinitis in three, bronchial asthma in three, and urticaria in one). There were no significant correlations between IgG, IgG4, and IgE (r = -0.168 for IgG, and r = -0.188 for IgG4). There was no significant difference in IgE in the patients with and without extrapancreatic lesions (526 ± 531 IU/mL vs 819 ± 768 IU/mL, P = 0.163), with and without clinical relapse (457 ± 346 IU/mL vs 784 ± 786 IU/mL, P = 0.374). There was no significant difference in IgE between before and after steroid treatment (723 ± 744 IU/mL vs 673 ± 660 IU/mL, P = 0.633).

CONCLUSION: Although IgE does not necessarily reflect the disease activity, IgE might be useful for the diagnosis of AIP in an inactive stage.

IgG₄-related sclerosing disease: a novel mimic of inflammatory bowel disease

High levels of IgG₄-positive plasma cells are commonly seen in autoimmune pancreatitis. It has recently become evident that autoimmune pancreatitis is one component of a larger multi-system disease. IgG₄-positive plasma cells have been identified in many extrapancreatic tissues, including the colon, biliary tract, liver, and lungs, and thus the term "IgG₄-related sclerosing disease" has been proposed. Awareness of IgG₄-related sclerosing disease is important, as it has been shown to mimic other conditions like malignancy. This review discusses IgG₄-related colitis and its potential for mimicking inflammatory bowel disease.

Chronic gastritis in the setting of autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a recently recognized disease entity. In some patients, this disease is associated with other inflammatory diseases. In this study, we aimed to elucidate the pathologic characteristics of AIP-associated gastritis (AIP-G). We evaluated and compared the pathologic findings and immunohistochemical expressions of immunoglobulin G (IgG)4 and IgG in gastric biopsy specimens from 13 AIP-G patients with those from patients of 2 control groups. We divided the AIP-G patients who did not receive steroid therapy [AIP-G-ST(-)] into the following 2 groups: without Helicobacter pylori (HP) infection [AIP-G-HP(-)] and with HP infection [AIP-G-HP(+)]. The control groups comprised 19 patients who were diagnosed with chronic active gastritis associated with HP infection and 7 patients with nonsteroidal anti-inflammatory drug-induced gastritis. We classified the findings for the gastric mucosa into those for the upper and the lower lamina propria. The characteristic finding of AIP-G groups was diffusely lymphoplasmacytic infiltration in the lamina propria. The IgG4-positive plasma cell/IgG-positive plasma cell ratios (IgG4/IgG ratios) in both the upper and lower lamina propria in the AIP-G-ST(-) groups were predominantly higher than the corresponding values in the other groups. In the AIP-G-ST(-) groups, the IgG4/IgG ratio in the lower lamina propria was predominantly higher than that in the upper lamina propria, irrespective of the HP status. In conclusion, diffuse lymphoplasmacytic infiltration in the lamina propria and increased IgG4/IgG ratio in the gastric mucosa (notably in the lower lamina propria) may be the characteristic findings of AIP-G.

Update on nonneoplastic pulmonary lymphoproliferative disorders and related entities

CONTEXT

Recent discoveries have expanded the spectrum of nonneoplastic pulmonary lymphoproliferative disorders and have provided new insights into their pathogenesis and treatment.

OBJECTIVE

To review the thoracic manifestations of immunoglobulin (Ig) G4-related sclerosing disease and summarize current concepts and differential diagnosis of follicular bronchiolitis, lymphocytic interstitial pneumonitis, and nodular lymphoid hyperplasia.

DATA SOURCES

Data sources include recent and old articles, cases from the personal files of the author, and cases borrowed with permission from other authors.

CONCLUSIONS

Additional studies will be needed to further refine and add to observations in this evolving area of pulmonary pathology.