International Consensus Guidance Statement on the Management and Treatment of IgG4-Related Disease

Immunoglobulin G subtypes-1 and 2 differentiate immunoglobulin G4-associated sclerosing cholangitis from primary sclerosing cholangitis

BACKGROUND

Autoimmune pancreatitis is a special form of chronic pancreatitis with strong lymphocytic infiltration and two histopathological distinct subtypes, a lymphoplasmacytic sclerosing pancreatitis and idiopathic duct centric pancreatitis. Immunoglobulin G4-associated cholangitis may be present at the time of autoimmune pancreatitis type 1 diagnosis or occur later over the course of the disease. Immunoglobulin G4 is considered reliable but not an ideal marker for diagnosis of autoimmune pancreatitis type 1 with reported sensitivity between 71-81%. It is essential to differentiate sclerosing cholangitis with autoimmune pancreatitis from primary sclerosing cholangitis as the treatment and prognosis of the two diseases are totally different. It was the aim of the study to find a marker for immunoglobulin G4-associated cholangitis that would distinguish it from primary sclerosing cholangitis.

PATIENTS AND METHODS

We performed a retrospective analysis of patients with autoimmune pancreatitis at our outpatient clinic. Patients from the primary sclerosing cholangitis registry were taken as a control group. Blood samples for the measurement of immunoglobulin subclasses were analysed at the time of diagnosis.

RESULTS

Patients with autoimmune pancreatitis and immunoglobulin G4-associated cholangitis had higher values of immunoglobulin G2 when compared to autoimmune pancreatitis alone or primary sclerosing cholangitis with a high specificity (97%) and high positive predictive value (91%). In patients with normal or low immunoglobulin G2 or immunoglobulin G4, a high level of immunoglobulin G1 indicated primary sclerosing cholangitis.

CONCLUSION

Immunoglobulin G1 and immunoglobulin G2 can distinguish patients with immunoglobulin G4-associated cholangitis from those with primary sclerosing cholangitis.

Diagnostic utility of submandibular and labial salivary gland biopsy in IgG4-related sialadenitis

OBJECTIVE

The diagnostic utility of labial salivary gland (LSG) biopsy for IgG4-related sialadenitis remains undetermined. The purpose of the present study was to determine whether submandibular gland biopsy could be replaced by LSG biopsy for diagnosing IgG4-RS.

PATIENTS AND METHODS

Medical records of two groups of patients were reviewed. Group A contained 45 patients suspected to have IgG4-RS who underwent both SMG and LSG biopsies. Group B contained 25 patients who were clinically and pathologically diagnosed with Sjögren syndrome (SS). Biopsy samples were stained using hematoxylin and eosin (HE) and immunohistochemical techniques and observed under an optical microscope. Relevant data describing histopathological characteristics were collected and analyzed.

RESULTS

SMG of IgG4-RS patients presented typical histopathological characteristics of fibrosis and IgG4-positive plasmacytic infiltration, while LSG showed varied characteristics. The sensitivity and accuracy of SMG for diagnosing IgG4-RS were greater than those of LSG (100% and 100% versus 55.3% and 75.7%, respectively, P < 0.05).

CONCLUSIONS

Biopsy of SMG showed greater sensitivity and specificity, whereas LSG biopsy showed varied histopathological and immunohistochemical characteristics; thus, SMG biopsy cannot be replaced by LSG biopsy for diagnosis of IgG4-RS.

Pleural effusion related to IgG4

Purpose of review

The causes of exudative pleural effusions are diverse and frequently remain unclear despite exhaustive examinations. Recently recognized IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder that can affect nearly any organ including the lungs. This review will focus on the involvement of IgG4 in exudative pleural effusion of unknown cause.

Recent findings

IgG4 is found to be involved in a proportion of patients with undiagnosed pleural effusions. Pleural involvement in IgG4-RD can be seen in isolation or association with other organ disease. Pleural thickening and/or effusion are common clinical features of IgG4-related pleural lesions, and this condition is histologically characterized by a lymphoplasmacytic infiltrate enriched in IgG4-positive plasma cells in the pleura. Although the pathogenesis of IgG4-RD is poorly understood, there is a growing body of evidence that indicates an antigen-driven process requiring T-cell and B-cell interaction in which autoantibodies, plasmablasts, follicular helper T cells and CD4+ cytotoxic T lymphocytes participate.

Summary

The possibility of IgG4-related pleural lesion should be considered in patients with pleural effusion of unexplained cause when lymphoplasmacytic infiltration is seen in a pleural biopsy specimen. This condition is responsive to systemic steroid therapy.

Clinical characteristics of IgG4-RD patients infected with COVID-19 in Hubei, China

Objective

IgG4-related disease (IgG4-RD) is an immune-mediated multi-organ, chronic and progressive disease. Therefore, we conducted a study to investigate the susceptibility of COVID-19 in IgG4-RD patients in Hubei province, and to characterize the clinical manifestation of COVID-19 in IgG4-RD patients.

Methods

A follow-up system that includes over 200 IgG4-RD patients across the country during the past ten years. A total of ninety-one patients with IgG4-RD who live in Hubei, China were identified and responded to our survey. Medical history, clinical symptoms, laboratory tests, CT imaging, and treatment were obtained through a standardized data collection form, and then independently reviewed by two investigators.

Results

2 of 91 cases were infected with COVID-19. Both of them were classified as moderate type. The symptoms such as fever and cough and radiologic features were similar to other COVID-19 patients. Neither of them episode recurrent of IgG4-RD nor progressed to severe or critical condition of COVID-19 under the condition of continuous oral low-dose of glucocorticoids. Besides, patient 2 took a long time for SARS-CoV-2 nucleic acid to turn negative.

Conclusion

IgG4-RD patients may belongs to the susceptible population of COVID-19 infection, and thus need more careful personal protection. Early identification and properly treatment are very important to prevent IgG4-RD patients with COVID-19 from progression to severe condition.

Definite IgG4-related disease had no overlap with eosinophilic granulomatosis with polyangiitis in Korean patients: a pilot study in one centre

OBJECTIVES

Serum IgG4 may often increases in allergic diseases. Eosinophilic granulomatosis with polyangiitis (EGPA) has an allergic phase. For this reason, it was questionable whether IgG4-RD and EGPA may share some clinical and laboratory features. In this study, we investigated whether definite IgG4-RD might share those features with EGPA.

METHODS

We retrospectively reviewed the medical records of 42 Korean immunosuppressive drug-naïve patients with definite IgG4-RD. The American College of Rheumatology 1990 criteria for classification (the 1990 ACR criteria) for Churg-Strauss syndrome (CSS, known as EGPA) were applied to patients who were previously diagnosed with definite IgG4-RD and had no antineutrophil cytoplasmic antibody (ANCA). Definite IgG4-RD was defined when 3 components of the comprehensive diagnostic criteria were met.

RESULTS

The median age of 42 patients was 61.0 years and 69% of them were men. The median serum IgG4 level was 379.0 mg/dL and the median IgG4+/IgG+ cells ratio was 50.0%. The most common biopsy site was the salivary gland (14.3%). Antinuclear antibody was detected in 6 patients, and test results for ANCA were negative in all patients. Among 42 patients with definite IgG4-RD without ANCA, none of them met the 1990 ACR classification criteria for EGPA.

CONCLUSIONS

Definite IgG4-RD found to have no overlap with EGPA when the 1990 ACR criteria for CCS were applied to Korean patients. Key Points • None of 42 Korean patients with definite IgG4-RD without ANCA met the 1990 ACR classification criteria for EGPA. • Definite IgG4-RD found to have no overlap with EGPA in Korean patients without ANCA.

CT Findings of Upper Urinary Tract Lesions in IgG4-Related Disease: Comparison With Urothelial Carcinoma

OBJECTIVE. IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and fibrosis in various organs. The objective of this study is to investigate CT findings of IgG4-related lesions involving the upper urinary tract and compare them with those of urothelial carcinomas. MATERIALS AND METHODS. This study reviewed pretreatment CT images of 13 consecutive patients with IgG4-related disease with upper urinary tract lesions and 80 consecutive patients with urothelial carcinomas. The findings assessed were laterality, location, growth pattern, margins, internal structure, presence of calcification and lipid component, enhancement pattern, and extraurinary findings. RESULTS. Bilaterality (p < 0.0001), an extramural growth pattern (p < 0.0001), a greater number of affected segments (p = 0.04), and a gradual dynamic enhancement pattern (p < 0.001) were significantly more frequent in patients with IgG4-related disease. With regard to extraurinary findings, paraaortic fat stranding (p = 0.03), presacral fat stranding (p < 0.001), fat stranding of the pelvic walls (p < 0.001), and aortic involvement (p < 0.001) were seen more frequently in patients with IgG4-related disease; on the other hand, there was no statistically significant difference in terms of frequency of pancreatic involvement. Hydronephrosis and renal involvement were seen more frequently in patients with urothelial carcinoma, although the difference was not statistically significant. CONCLUSION. CT findings suggestive of IgG4-related upper urinary tract lesions in comparison with urothelial carcinoma are bilateral and have a longer urinary tract involvement and exhibit an extramural growth pattern, ill-defined margins, a gradual enhancement pattern, aortic involvement, and fat stranding in the paraaortic, presacral, or pelvic wall areas.

IgG4-related disease: a clinical perspective

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder that can affect almost any organ. Common presentations include major salivary and lacrimal gland enlargement, orbital disease, autoimmune pancreatitis, retroperitoneal fibrosis and tubulointerstitial nephritis. The main histopathological features are a dense, polyclonal, lymphoplasmacytic infiltrate rich in IgG4+ plasma cells, storiform fibrosis and obliterative phlebitis. The precise pathogenic mechanisms of IgG4-RD are still unclear. CD4+ T and B cells, including IgG4-expressing plasmablasts, constitute the major inflammatory cell populations and are believed to cause organ damage and tissue fibrosis. The diagnosis of the disease may be challenging and should be based on specific histopathological findings, typical laboratory and radiological aspects and an appropriate clinical context. The first-line treatment of IgG4-RD is based on glucocorticoids, which are usually efficacious. However, B cell depletion induced by rituximab has also been found to induce remission in steroid-resistant disease or has been used as steroid-sparing agent for relapsing disease. This review provides an update on clinical and therapeutic aspects of IgG4-RD.

Diagnosis and treatment of autoimmune and IgG4-related hypophysitis: clinical guidelines of the Japan Endocrine Society

Hypophysitis, which is often accompanied by pituitary dysfunction, is classified into several subtypes based on the cause, histology, and the location of inflammation in the pituitary gland. A definitive diagnosis requires pituitary biopsy, which is invasive, and the process is limited to specialized clinical settings. In this opinion paper, we review the literature associated with hypophysitis, and provide the guidelines of the Japan Endocrine Society for the diagnosis and treatment of autoimmune and IgG4-related hypophysitis.

IgG4 hypophysitis: Diagnosis and management

IgG4-related hypophysitis is a rare disease, due to a lymphoplasmocytic IgG4 positive infiltration of the pituitary. Literature data are scarce, even though the description of cases has drastically increased over the last years. The aim of this review is to better characterize the natural history, the diagnosis and the management of IgG4-related hypophysitis, based on a clinical case, an exhaustive Pubmed research, and a reappraisal of the criteria for diagnosis. We will specifically focus on the differences with other etiologies of hypophysitis, in the aim of improving the diagnostic procedures for all the physicians who could have to take care of such patients.

Sclerosing sialadenitis of the submandibular gland is rarely an immunoglobulin G4-related disease in the Finnish population

Chronic sclerosing sialadenitis may represent one of many manifestations of an immunoglobulin G4-related disease. However, existing studies typically consist of small patient cohorts rarely conducted in Western populations. The clinical behavior of chronic sclerosing sialadenitis, including follow-up data, warrants further study. Thus, we aimed to determine whether chronic sclerosing sialadenitis always presents as IgG4-related disease or associates with autoimmune diseases and to determine which additional examinations patients may require. Between 2000 and 2017, 51 patients undergoing submandibular gland resection within the Helsinki University Hospital area were diagnosed with chronic sclerosing sialadenitis. We re-evaluated all specimens and performed immunostaining for IgG4. IgG and CD31 stainings were performed for IgG4-positive specimens. IgG4-related disease diagnosis was defined by the Boston consensus statement criteria. We revised clinical data, distributing a follow-up questionnaire to patients to register symptoms of IgG4-related disease or autoimmune disease during follow-up. The chronic sclerosing sialadenitis criteria were fulfilled in 34 patients, whereby 17 were diagnosed as non-sclerosing chronic sialadenitis. In 19 cases, a sialolith associated with a salivary gland lesion. In total, 12 of 51 cases were recognized as IgG4-positive, while two met the criteria for IgG4-related disease. These two cases belonged to the non-sclerosing chronic sialadenitis group, and both involved other organs. The histopathological features between chronic sclerosing sialadenitis and non-sclerosing chronic sialadenitis overlapped regarding the degree of fibrosis and inflammatory infiltrates. In the Finnish population, chronic sclerosing sialadenitis of the submandibular gland does not appear to present as IgG4-related disease. Non-sclerosing chronic sialadenitis can associate with IgG4-related disease. A histopathological distinction between chronic sclerosing sialadenitis and non-sclerosing chronic sialadenitis is not always unequivocal and the presence of a sialolith does not exclude IgG4-positivity. Therefore, immunostaining for IgG4 should be performed when dense plasma cell infiltration is present in either non-sclerosing chronic sialadenitis or chronic sclerosing sialadenitis.

Long-term efficacy of maintenance therapy with Rituximab for IgG4-related disease

BACKGROUND

IgG4-Related Disease (IgG4-RD) promptly responds to glucocorticoids but relapses in most patients. Rituximab (RTX) represents a promising strategy to avoid IgG4-RD flares but its administration for maintaining disease remission has never been assessed in terms of optimal timing of infusion, dosage, and duration of treatment. In the present study we aimed to evaluate the efficacy and safety of RTX for maintenance of IgG4-RD remission.

METHODS

Fourteen patients with IgG4-RD were treated with RTX as induction of remission therapy at the San Raffaele Scientific Institute in Milan, Italy. The cohort was then divided into two study groups: patients re-treated only in case of disease relapse (Group 1, n = 7), and patients regularly re-treated with RTX every 6 months for maintenance therapy (Group 2, n = 7). Data on free-relapse rate and adverse events were collected and retrospectively analysed.

RESULTS

Median follow-up time and baseline clinical-serological features were similar between Group 1 and 2 (p > 0.05). The free relapse rate 18 months after induction of remission treatment was significantly lower in Group 1 (29%) than in Group 2 (100%) (p = 0.006). Infectious complications developed in 6/14 patients (3 in Group 1 and 3 in Group 2).

CONCLUSION

Administration of RTX every 6 months as maintenance of remission therapy prevents IgG4-RD flares.

Immunoglobulin G4-related Disease

Immunoglobulin G4 (IgG4)-Related Disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ and lead to organ dysfunction and irreversible damage. In addition to frequent involvement of the salivary glands, lacrimal glands, and/or pancreas, IgG4-RD often affects the chest. Thoracic manifestations include lung nodules and consolidations, pleural thickening, aortitis, and lymphadenopathy. The diagnosis is made after careful clinicopathologic correlation because there is no single diagnostic test with excellent sensitivity or specificity. Biopsy of pulmonary lesions can be useful for distinguishing IgG4-RD from common mimickers. Immunosuppressive regimens, such as glucocorticoids and/or glucocorticoid-sparing agents, form the cornerstone of treatment.

Renal involvement in IgG4-related disease

IgG4-RD may affect several organs including kidneys. The kidney is involved in approximately 20% of patient with IgG4-RD. The most common intrinsic kidney disease is tubulointerstitial nephritis (IgG4-TIN). Retroperitoneal fibrosis (IgG4-RPF) may induce obstructive acute renal failure. More rarely, IgG4-RKD can manifest as a glomerular disease, in particular as a membranous nephropathy (MN). It mostly affects middle-aged to elderly men and causes acute or chronic renal dysfunction, multiple hypodense lesions on CT-Scan and various extra-renal lesions. Increased serum IgG4 and hypocomplementemia are the most important serological findings for the diagnosis of IgG4-RD and thus should be systematically assessed when IgG4-RKD is suspected. Specific diagnosis criteria for IgG4-TIN including interstitial infiltration of IgG4-positive plasma cells, storiform fibrosis and tubular basement membrane immune complex deposits have been proposed. Corticosteroids are effective and remain the first-line therapy but relapses or severe forms could respond to immunosuppressive therapy.

IgG4-related pleural disease with aortitis and submandibular glands involvement successfully treated with corticosteroid: case-based review

IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition characterized by increased serum IgG4 level, infiltration of lymphocytes and IgG4-positive (IgG4⁺) plasma cells and fibrosis. It can occur in almost all organs, commonly affecting the pancreas, biliary tract, salivary and lacrimal glands and kidneys. However, reports of IgG4-RD accompanied by pathologically confirmed, IgG4-related pleural disease are scarce. Here, we present a case of a 64-year-old man with suspected malignant pleural mesothelioma based on imaging findings but finally diagnosed with IgG4-RD (including pleuritis, periaortitis and bilateral submandibular gland enlargement) based on a high serum IgG4 level and pleural histopathological findings such as lymphoplasmacytic infiltration including IgG4⁺ plasma cells and fibrosis. Systemic corticosteroid therapy was effective at reducing serum IgG4, improving bilateral submandibular gland enlargement, and regressing pleural thickening and periaortic soft tissue. We also discuss clinical characteristics and pleural pathological features of previously reported cases with IgG4-related pleural disease based on a comprehensive literature review. Our case of IgG4-RD with pleura, aorta and submandibular gland involvement, pathologically confirmed by pleural specimen might be unique and very rare.

Development of efficient on-bead protein elution process coupled to ultra-high performance liquid chromatography-tandem mass spectrometry to determine immunoglobulin G subclass and glycosylation for discovery of bio-signatures in pancreatic disease

Type 1 autoimmune pancreatitis (AIP) is a kind of IgG4-related disease in which higher IgG4 and total IgG levels have been found in patient serum. Due to the similar imaging features and laboratory parameters between AIP and pancreatic ductal adenocarcinoma (PDAC), a differential diagnosis is still challenging. Since IgG profiles can be potential bio-signatures for disease, we developed and validated a method which coupled on-bead enzymatic protein elution process to an efficient UHPLC-MS/MS method to determine IgG subclass and glycosylation. A stable-isotope labeled IgG was incorporated as internal standard to achieve accurate quantification. For calibration curves, the correlation coefficients for total IgG and the four IgG subclasses were higher than 0.995. Intraday (n = 5) and interday (n = 3) precisions of the peak area ratios of LLOQ, low, medium, and high QC samples were all less than 6.6% relative standard deviation (% RSD), and the accuracies were between 93.5 and 114.9%. Calibration curves, precision, and accuracy were also evaluated for 26 IgG glycopeptides. The method was applied to samples from healthy controls and patients with AIP and PDAC. Distinct IgG patterns were discovered among the groups, and 7 glycopeptides showed high potential in differentiating AIP and PDAC. The results demonstrated that the developed method is suitable for multi-feature analysis of human IgG, and the discovered IgG profiles can be used as bio-signatures for AIP and PDAC.

Cryotherapy Ablation in Immunoglobulin G4-Related Disease of the Trachea

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition comprising a group of disorders with shared clinicopathologic features. Manifestations of IgG4-RD are increasingly recognized in multiple organs, but tracheal involvement remains rare. Patients may present with a mass in the affected organ and most will respond to glucocorticoids, particularly in early stages of disease; however, between 15% and 60% of patients will experience relapse. We consider cryotherapy effective and safe for tumor debulking and symptomatic relief in IgG4-RD. We report on a case of a patient with upper tracheal stenosis exhibiting marked reduction in tumor size and symptom burden, after cryotherapy ablation.

IgG4-related orbitopathy as an important differential diagnosis of advanced silent sinus syndrome

BACKGROUND

Immunoglobulin (Ig)G4-related disease is classified as an immune-mediated disease. The etiology of this condition has not been explained to date. Manifestations of the disease are diverse, and simultaneous involvement of multiple organs is not unusual.

CASE REPORT

We report the case of a patient referred to us after multiple unsuccessful paranasal sinus operations who presented with enophthalmos and a resultant migratory keratitis with a suspected diagnosis of silent sinus syndrome. Preservation of the orbit was no longer feasible. After five years without a definitive diagnosis, we ascertained that this was a case of IgG4-related disease.

DISCUSSION

IgG4-related disease represents an important element in the differential diagnosis of chronic advanced diseases of the orbit and paranasal sinuses. The diagnosis should be considered in the case of unclear disease presentations. Typical histological findings include a storiform pattern of fibrosis, vasculopathy, and tissue infiltration by IgG4 plasma cells.

Superior vena cava stenting in IgG4-associated mediastinal fibrosis

We report a rare case of IgG4-associated mediastinal fibrosis with complete superior vena cava (SVC) obstruction successfully managed by thrombolysis and stenting in a 33-year-old male. The patient presented with a mediastinal mass lesion with clinical findings of SVC obstruction. Surgical biopsy of the mediastinal mass lesion with histology and immunohistochemistry staining established the diagnosis of IgG4 associated mediastinal fibrosis. The patient was treated with a systemic steroid and rituximab, but despite treatment, SVC obstruction and thromboses persisted, surgical intervention was declined by the thoracic surgeon due to extensive mediastinal fibrosis and an expected poor outcome. Percutaneous SVC angioplasty, intravascular thrombolysis with tissue plasminogen activator and afterward stent placement was done by the interventional radiology service. This intervention is rare and possibly was lifesaving as it restored complete patency of the SVC. Our case is probably the first with IgG4 mediastinitis and SVC complete obstruction relieved by intravascular thrombolysis and SVC stent placement. It demonstrates that SVC stenting can relieve SVC obstruction in patients with a high risk of surgery either due to medical comorbidities or an expected high surgical risk like bleeding in the mediastinal fibrosis, which in our case of SVC obstruction was due to a nonoperable mediastinal tumor. SIMILAR CASES PUBLISHED: None to our knowledge.

IgG4-Related Lung Disease Exhibiting the Invasion into the Diaphragm: A Case Report

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition which involves various organs. This is a very rare case of IgG4-related lung disease (IgG4-RLD) with the invasion into diaphragm. The patient was a 71-year-old man with a long-term exposure to asbestos who had a mass shadow in the left lower lung lobe, which was suspected to invade the left diaphragm on computed tomography (CT). Positron emission tomography (PET)/CT also presented an avid intake of fluorodeoxyglucose in the mass, which suspected lung cancer. Although bronchoscopic biopsy could not lead to the definite diagnosis, we performed left lower lobectomy combined with the resection of left diaphragm. The specimen showed the features of IgG4-RLD on pathology: the vein stenosis and fibrosis around the vein, the infiltration of IgG4-positive cells, and IgG cells to IgG4 cells ratio of 40%. Furthermore, there were inflammatory cells infiltrating to the diaphragm.

IgG4-related disease presenting as otogenic skull base osteomyelitis

IgG4-related disease (IgG4-RD) is an emerging clinical disease entity characterized by tumefactive lesions at multiple sites with a dense lymphoplasmacytic infiltrate rich in IgG4+ plasma cells. Although almost any organ can be affected, IgG4-RD is most likely to involve the submandibular, lacrimal, or parotid glands in the head and neck region. However, skull base involvement presenting as otogenic skull base osteomyelitis (SBO) is rare. We encountered a 70-year-old male with IgG4-RD presenting primarily with severe otalgia and otorrhea. He had uncontrolled diabetes mellitus and showed clinical manifestations of otogenic SBO. Tissue immunostaining revealed typical features of increased IgG4-positive plasma cells, and hematological examination showed elevated serum IgG4 concentrations. Treatment with corticosteroids significantly improved well-being and partially resolved the lesion based on computed tomography (CT) scan.

Calcifying fibrous tumour: An IgG4-related disease or not?

Calcifying fibrous tumour (CFT) has some of the histopathological features, such as abundant plasma cells and stromal fibrosis, that are exhibited by IgG4-related diseases (IgG4-RD). The possible role of IgG4-positive plasma cells in calcifying fibrous tumour was investigated. The aim of this study was to determine any potential relationship between IgG4-RD and CFT. Thirteen cases with a total of 16 CFTs were reviewed. Lesion samples were immunostained with anti-IgG4 and anti-IgG antibodies. The number of IgG4-positive and IgG-positive plasma cells (IgG + PC) and their ratios were estimated. Plasma cells were found in all tumours. IgG4-positive plasma cells ranged from 0 to 71 per high-power field (HPF; mean 17.8/HPF), and IgG + PC ranged from 2 to 93/HPF (mean 42.6/HPF). The IgG4/IgG ratio ranged from 0% to 80% (mean 29%). There were seven tumours with the ratio of IgG4/IgG + PC that exceeded 40%. Various degrees of stromal fibrosis were present in eight tumours. All tumours have variable calcification. The histopathological features of CFT were found to be similar to those of IgG4-RD. Some CFT also showed a high number of IgG4-positive plasma cells, and the ratio of IgG4/IgG + PC exceeded 40%, most notably in patients with concomitant inflammatory or autoimmune disease. The long-term follow-up showed no evidence of IgG4-RD in any of these patients. Our findings suggest that while CFT overlaps morphologically with IgG4-RD, it probably should not be classified as an IgG4-RD.

Arterial-bronchial fistula from ruptured immunoglobulin G4-related subclavian artery aneurysm

Immunoglobulin G4 (IgG4)-related disease is a systemic chronic inflammatory disease caused by infiltration of IgG4-positive plasma cells into the systemic organs. IgG4-related arterial disease is relatively rare not only in the aorta but also in the small to medium-sized arteries. If IgG4-related vasculitis is suspected on the basis of the preoperative medical history and radiologic and serologic examination findings, a definitive diagnosis can be obtained by open repair and pathologic examination to determine the prognosis and need for additional treatment. Here, we report the successful treatment of arterial-bronchial fistula caused by a ruptured IgG4-related subclavian artery aneurysm.

Orbital inflammation and colitis in pediatric IgG4-related disease: A case report and review of the literature

IgG4-related disease (IgG4-RD) is an inflammatory disorder characterized by tumor-like swelling in one or more organs, elevated serum IgG4 levels, and histological alterations with infiltration of IgG4-positive plasma cells. IgG4-RD is rare and likely underdiagnosed in children. We report a case of a 16-year-old girl with IgG4-positive colitis that developed weeks after IgG4-related ophthalmic disease and discuss diagnosis and treatment in the context of the literature available. Since the pathophysiology of IgG4-RD is unknown, treatment options are empiric and, for the most part, untargeted. Systemic corticosteroid treatment is the basis of anti-inflammatory treatment in IgG4-RD and induced early remission in our patient. During corticosteroid taper, the patient developed weight loss and intestinal inflammation. Histopathological assessment of the intestinal walls confirmed IgG4-positive colitis. Immune-modulating treatment with non-biologic (e.g., methotrexate (MTX) and mycophenolate mofetil) or biologic (rituximab) disease-modifying antirheumatic drugs has been reported in treatment refractory or corticosteroid-dependent patients. The patient responded to treatment with anti-inflammatory therapy with food rich in TGF-β2 (modulen) and MTX. This is one of the first pediatric patients reported with IgG4-related colitis extending the phenotype of pediatric IgG4-RD. International collaboration to prospectively document clinical presentation and treatment responses may help to further establish the phenotype and treatment options and to raise awareness for IgG4-RD.

Review of a novel disease entity, immunoglobulin G4-related disease

Immunoglobulin G4 (IgG4)-related dacryoadenitis and sialoadenitis (IgG4-DS) are part of a multiorgan fibroinflammatory condition of unknown etiology termed IgG4-related disease (IgG4-RD), which has been recognized as a single diagnostic entity for less than 15 years. Histopathologic examination is critical for diagnosis of IgG4-RD. CD4+ T and B cells, including IgG4-expressing plasma cells, constitute the major inflammatory cell populations in IgG4-RD and are thought to cause organ damage and tissue fibrosis. Patients with IgG4-RD who have active, untreated disease exhibit significant increase of IgG4-secreting plasmablasts in the blood. Considerable insight into the immunologic mechanisms of IgG4-RD has been achieved in the last decade using novel molecular biology approaches, including next-generation and single-cell RNA sequencing. Exploring the interactions between CD4+ T cells and B lineage cells is critical for understanding the pathophysiology of IgG4-RD. Establishment of pathogenic T cell clones and identification of antigens specific to these clones constitutes the first steps in determining the pathogenesis of the disease. Herein, the clinical features and mechanistic insights regarding pathogenesis of IgG4-RD were reviewed.

IgG4-related acute interstitial nephritis and the potential role of mCRP autoantibodies: a case report

Background: IgG4-related acute tubulointerstitial nephritis is a type of autoimmune-mediated interstitial nephritis. Recently, autoantibodies against modified C-reactive protein (mCRP) were found to play a pathogenic role in renal diseases through the formation of tubulointerstitial lesions. This is the first case report on the presence of mCRP autoantibodies in a patient with IgG4-associated acute tubulointerstitial nephritis.

Case presentation: A 70-year-old man was admitted with renal dysfunction and a medical history of bile duct stenosis, an inflammatory pancreatic mass, hypertension, and diabetes. On admission, laboratory tests showed higher than normal levels of serum creatinine and IgG4 and lower than normal levels of complements 3 and 4. In addition, the mCRP autoantibody levels were elevated, and the findings of kidney biopsy revealed interstitial nephritis with rich plasma cells in the renal interstitium. The patient was administered prednisone and cyclophosphamide therapy, which resulted in a rapid improvement in renal function.

Conclusion: IgG4-related autoimmune disease should be considered in the diagnosis of patients who have tubulointerstitial nephritis with multisystem involvement. Further, mCRP autoantibodies may be associated with IgG4-related tubulointerstitial nephritis and might be useful as a diagnostic marker of the disease.

IgG4-Related Sclerosing Cholangitis and Primary Sclerosing Cholangitis

Sclerosing cholangitis (SC) is defined as a condition with progressive stenosis and destruction of the bile ducts due to diffuse inflammation and fibrosis and currently includes three categories: primary sclerosing cholangitis (PSC), secondary cholangitis, and IgG4-related sclerosing cholangitis (IgG4-SC). SC categories share similar clinical features, such as cholestasis. Patients with SC present with cholestatic symptoms, including jaundice and pruritus, and blood tests reveal elevation of cholestatic enzymes. Cholangiography, endoscopic or magnetic, is inevitably required for making a diagnosis. Although the presentation of IgG4-SC and PSC are similar, the comorbidities, treatment response, and outcomes differ significantly, and therefore, it is strongly advisable to be familiar with these two diseases to make a correct diagnosis. Differentiation of cholangiocarcinoma from IgG4-SC and PSC is also extremely important. In this review, the clinical characteristics, comorbidities, treatment and outcomes of IgG4-SC and PSC will be outlined based on experience mainly from Japan.

Identifying clinical subgroups in IgG4-related disease patients using cluster analysis and IgG4-RD composite score

Background

To explore the clinical patterns of patients with IgG4-related disease (IgG4-RD) based on laboratory tests and the number of organs involved.

Methods

Twenty-two baseline variables were obtained from 154 patients with IgG4-RD. Based on principal component analysis (PCA), patients with IgG4-RD were classified into different subgroups using cluster analysis. Additionally, IgG4-RD composite score (IgG4-RD CS) as a comprehensive score was calculated for each patient by principal component evaluation. Multiple linear regression was used to establish the “IgG4-RD CS” prediction model for the comprehensive assessment of IgG4-RD. To evaluate the value of the IgG4-RD CS in the assessment of disease severity, patients in different IgG4-RD CS groups and in different IgG4-RD responder index (RI) groups were compared.

Results

PCA indicated that the 22 baseline variables of IgG4-RD patients mainly consisted of inflammation, high serum IgG4, multi-organ involvement, and allergy-related phenotypes. Cluster analysis classified patients into three groups: cluster 1, inflammation and immunoglobulin-dominant group; cluster 2, internal organs-dominant group; and cluster 3, inflammation and immunoglobulin-low with superficial organs-dominant group. Moreover, there were significant differences in serum and clinical characteristics among subgroups based on the CS and RI scores. IgG4-RD CS had a similar ability to assess disease severity as RI. The “IgG4-RD CS” prediction model was established using four independent variables including lymphocyte count, eosinophil count, IgG levels, and the total number of involved organs.

Conclusion

Our study indicated that newly diagnosed IgG4-RD patients could be divided into three subgroups. We also showed that the IgG4-RD CS had the potential to be complementary to the RI score, which can help assess disease severity.

IgG4-Related Diseases-Continues To Be a Cancer Mimicker

Immunoglobulin G4-related disease (IgG4-RD) is a chronic multisystem immune-mediated disease. Histologically, it presents as infiltration with IgG4-secreting plasma cells affecting many organs such as the pancreas, lacrimal glands, salivary glands, kidneys, and arteries, resulting in chronic fibrosis and scarring within the tissue which over time forms into a mass. It is a slow-growing process that usually remains indolent until it causes a mass effect or tissue infiltration. Our patient was found to have a pancreatic mass on imaging concerning pancreatic neoplastic lesions. He subsequently underwent biopsy for histology/pathology and IgG4 levels, which led to our diagnosis of IgG4-RD. Imaging, blood tests, and, most importantly, histopathological features of the involved organ are important in determining the diagnosis. This is important as a treatment plan will be based on the given diagnosis, and patients with IgG4-RD respond very well to systemic steroid therapy.

IgG4-related disease: How to place it in the spectrum of immune-mediated and rheumatologic disorders?

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder that results from massive expansion of polyclonal IgG4-switched B and/or plasma cells. It can virtually affect all organs and its diagnosis relies on clinical, serological and histopathological criteria. The role of autoimmunity and adaptive immune system in IgG4-RD is reflected in plasmablast differentiation, germinal center formation and IgG4 production induced by CD4+ cells expressing CD40 ligand. IgG4-RD has been considered to be a Th2/Treg-driven disorder, but follicular helper T cells are important in driving the IgG subclass switch. Prompt clinical responses to rituximab, human leukocyte antigen (HLA) associations and the presence of autoantibodies also point to the importance of adaptive immune system. However, innate immunity may induce storiform fibrosis through T-cell independent responses as a consequence of toll-like receptors activation by microbe-and damage-associated molecular patterns, while macrophages and basophils also appear to have a significant role in IgG4-RD pathogenesis. Allergic mechanisms may drive IgG4-RD, but only a subgroup has elevated IgE serum levels and peripheral eosinophilia. Finally, the 2012 revised Chapel Hill Consensus Conference nomenclature pointed IgG4-RD as a cause of large-vessel vasculitis. This review aims to discuss how to place IgG4-RD in the spectrum of immune-mediated and rheumatologic disorders.

Recurrent myelitis and asymptomatic hypophysitis in IgG4-related disease: case-based review

IgG4-related disease (IgG4-RD) is a disorder with various clinical manifestations. Central nervous system (CNS) involvement is well recognized, with hypertrophic pachymeningitis and hypophysitis being the most common manifestations. Spinal cord involvement is an extremely rare manifestation. We present the first case of an IgG4-RD patient with spinal cord parenchymal disease and concurrent hypophysitis. We review also the current literature about CNS parenchymal involvement in the context of IgG4-RD. A young female presented with clinical symptoms of myelitis. Cervical spinal cord magnetic resonance imaging (MRI) displayed features of longitudinally extensive transverse myelitis (LETM). Brain MRI showed a small number of high-intensity lesions in the deep white matter and enlargement of hypophysis with homogeneous gadolinium enhancement (asymptomatic hypophysitis). Diagnostic workup revealed elevated IgG4 serum levels (146 mg/dL). Our patient fulfilled the organ-specific diagnostic criteria of IgG4-hypophysitis. Treatment with intravenous glucocorticoids led to rapid clinical response, and to the substantial resolution of imaging findings. Azathioprine was used as a maintenance treatment. One relapse occurred 2 years after the initial diagnosis and patient was re-treated with glucocorticoids. Three years after relapse, patient is in remission with azathioprine. We present the first case of myelitis with radiological features of LETM associated with increased IgG4 serum levels and the simultaneous presence of asymptomatic IgG4-related hypophysitis.

Two cases of immunoglobulin G4 (IgG4)-related hypophysitis diagnosed without pituitary biopsy

BACKGROUND

Immunoglobulin G4-related hypophysitis (IgG4-RH) is a rare disease, diagnosis of which typically depends on histopathology following an invasive pituitary biopsy, possibly leading to permanent hypopituitarism. Herein, we report two cases of IgG4-RH with favorable responses to glucocorticoids. One of them was multiple organs involved and treated with glucocorticoids and methotrexate.

METHODS

We retrospectively review clinical features, radiological images, and treatment of two cases with IgG4-RH. In addition, literature on IgG4-RH was comprehensively reviewed and a new therapeutic strategy for IgG4-RH was provided.

RESULTS

A 45-year-old man presented with diabetes insipidus for 6 months. Pituitary magnetic resonance imaging (MRI) indicated thickening of pituitary stalk. His serum IgG4 was 13,500 mg/l and hormonal evaluation revealed isolated growth hormone deficiency. Pituitary biopsy was denied by the patient due to fears of permanent pituitary damage. Treatment with prednisone and methotrexate (MTX) for 1 week led to improvement in sellar images and reduction in IgG4 level. His IGF1 (insulin-like growth factor-1) recovered after a 4-month treatment. The second case is a 43-year-old woman presenting with diabetes insipidus and amenorrhea for 20 months. Her pituitary MRI was similar to the patient above. Her serum IgG4 level was 5980 mg/l and hormonal measurement confirmed isolated hypogonadotropic hypogonadism. After 2 weeks of prednisone, the sellar images improved. After 3 months of treatment, her pituitary MRI was normal, IgG4 level had decreased to near normal range, and menstruation resumed. Literature review found additional patients with IgG4-RH, who were treated successfully without invasive pituitary biopsy in a manner similar to our cases. Therefore, we discuss the necessity of invasive pituitary biopsy for IgG4-RH.

CONCLUSION

For suspected IgG4-RH with pituitary hormone deficiency, biopsy-induced hypopituitarism may be avoided by using diagnostic glucocorticoid treatment. Impaired pituitary hormone secretion may be recovered in response to steroid therapy. Improved pituitary MRI after 1-2 weeks of glucocorticoid treatment may provide diagnostic evidence of IgG4-RH.

Hypophysitis (Including IgG4 and Immunotherapy)

Hypophysitis is characterized by inflammation of the pituitary gland that can be primary (PH) or secondary (SH) to other diseases or following drug administration. It may also be classified according to anatomical and histopathological criteria, leading to variable degrees of hypopituitarism and/or compressive symptoms to nearby structures. There has recently been an increase in the number of hypophysitis cases, raising the interest on the spectrum of its pathogenesis, clinical, biochemical/endocrinological, and imaging features. However, the use of conventional biomarkers, including currently utilized pituitary autoantibodies, has relatively limited diagnostic accuracy. Lymphocytic hypophysitis (LH) is the commonest cause of PH, whereas IgG4-related hypophysitis is increasingly being recognized. Histiocytosis and granulomatous diseases are the most frequent causes of SH, although infections and lymphoma have also been reported. The increasing use of immune checkpoint inhibitors in oncology is associated with a high incidence of hypophysitis, providing further understanding of its pathogenesis. Hypophysitis can occur silently and be easily missed, potentially leading to substantial morbidity or mortality due to adrenal insufficiency, requiring a high index of clinical suspicion and timely initiation of appropriate treatment. In most cases of LH or drug-induced hypophysitis, active surveillance along with replacement of established hormonal deficiencies is needed. In the presence of compressive and/or evolving symptoms, treatment with glucocorticoids either alone or in combination with other immunosuppressive agents can be used. Surgical decompression is reserved for nonresponsive cases with threatened vital structures. Timely diagnosis and intervention are important to minimize disease-related morbidity and mortality. We aimed to review current concepts and recent developments in the pathogenesis, diagnosis, and management of hypophysitis.

Clinical and Pathological Characteristics of IgG4-Related Periaortitis/Periarteritis and Retroperitoneal Fibrosis Diagnosed Based on Experts' Diagnosis

IgG4-related disease is a systemic disease, characterized by elevation of serum IgG4 and, histopathologically, massive infiltration of IgG4+ lymphocyte and plasma cell infiltration, storiform fibrosis, causing enlargement, nodules or thickening. It may affect various organs simultaneously or metachronously. Here we analyzed the clinical and pathological characteristics of 99 patients diagnosed with IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis. Of 99 patients (women/men, 15/84; mean age 67.3±9.5 years), 33 were diagnosed based on the histopathological findings of perivascular/retroperitoneal lesions, 50 were diagnosed based on the characteristic imaging findings of perivascular/retroperitoneal lesions and the presence of definitive IgG4-related disease in other organ(s), and the remaining 16 patients were diagnosed by experts based on the characteristic imaging findings of perivascular/retroperitoneal legions, serological findings, response to glucocorticoid treatment, and/or the presence of suspected IgG4-related disease in other organ(s). According to the new organ-specific criteria proposed by experts, 73 (73.7%) diagnoses were categorized to be definitive, and 6 (6.1%) and 17 (17.2%) diagnoses were categorized to be probable and possible, respectively. Further analyses are needed to clarify the optimal diagnostic and therapeutic strategy of IgG4-related periaortitis/periarteritis and retroperitoneal fibrosis. (This is a translation of J Jpn Coll Angiol 2018; 58: 117–129.)

Efficacy and safety of iguratimod on patients with relapsed or refractory IgG4-related disease

OBJECTIVE

To evaluate the therapeutic efficacy and safety of iguratimod on patients with relapsed or refractory IgG4-related disease (IgG4-RD).

METHODS

We conducted a retrospective single-center study in 17 IgG4-RD patients admitted to Peking University People's Hospital. Patients were given iguratimod, 25 mg, twice daily and clinical data were collected at 0, 12, and 24 weeks. The baseline treatments include prednisone, cyclophosphamide, leflunomide, mycophenolate mofetil, and methotrexate. Clinical manifestation, IgG4-RD responder index (IgG-RD RI), serological indexes, gland ultrasound findings, and adverse drug effect were recorded. IgG4-RD RI scores < 3 and declining ≥ 2 were recognized as complete response (CR); IgG4-RD RI scores declining ≥ 2 but remaining ≥ 3 were recognized as partial response (PR). If a patient's IgG4-RD RI score was 3 at the beginning, PR was considered as a 1-point decrease after the therapy.

RESULTS

Serum IgG4 decreased significantly from 708 (321-902) mg/dl at baseline to 446 (138-396) mg/dl at 24 weeks (P = 0.0016). IgG4-RD RI decreased significantly from 9.79 ± 3.07 at baseline to 3.57 ± 1.09 at 24 weeks (P < 0.0001). Overall, 2 (14.3%) patients achieved CR, 11 (78.6%) patients achieved PR, and 1 (7.14%) patient had no response to treatment at week 24. Serum IgG level and salivary glands major diameter also decreased significantly at week 12 and 24 after treatment.

CONCLUSION

Iguratimod can be a therapeutic strategy to achieve remission in relapsed or refractory IgG4-RD patients inadequately responding to corticosteroid treatment with or without other immunosuppressant treatment. Key messages • Iguratimod was effective for relapsed or refractory IgG4-RD patients. • Iguratimod can improve the clinical symptoms of patients, reduce the serum IgG and IgG4 levels, and can also reduce the volume of involved glands.

An overlap of antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and IgG4-related kidney disease

BACKGROUND

We investigated the characteristics of antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (ANCA-GN) and immunoglobulin G4 (IgG4)-related kidney disease (IgG4-RKD) overlap syndrome.

METHODS

This is a 2-center study with 19 patients.

RESULTS

Fifteen patients were classified as microscopic polyangiitis (MPA). The initial serum creatinine levels were 320.9 ± 191.4 μmol/l and the BVAS was 19.7 ± 7.4 at diagnosis. Hematuria was absent or slight in 13 (68.4%) cases. Renal histology of these patients revealed concurrent ANCA-GN and IgG4-RKD. Regarding the histological classification of ANCA-GN, 9 (47.4%), 8 (42.1%), 1 (5.3%) and 1 (5.3%) patients were classified as focal, crescentic, mixed and sclerotic ANCA-GN, respectively. MPO-ANCA could be detected in 17/19 (89.5%) patients. IgG subclasses of MPO-ANCA were tested in 10 patients, and all were positive for IgG4-MPO-ANCA. In patients with combined ANCA-GN and IgG4-RKD, the percentage of positive IgG1-MPO-ANCA was significantly lower than the control group of 20 AAV patients without IgG4-RKD (P = 0.002), and the percentage of positive IgG4-MPO-ANCA was higher than the control group, but this difference was not statistically significant (P = 0.14).

CONCLUSIONS

ANCA-GN and IgG4-RKD overlap syndrome concerned mainly MPO-ANCA positive patients. The IgG subclass analysis of MPO-ANCA showed lower percentage of IgG1 subclass. The association between ANCA-GN and IgG4-RKD is possible and represents a special entity.

Immunoglobulin G4-Related Mastitis: An Unusual Case of Recurrent Breast Abscess

Immunoglobulin G4-related mastitis (IgG4-RM) is an uncommon entity in clinical practice which has an evolving spectrum of manifestations and presently is of high clinical interest among rheumatologists. Since its closest differential remains breast carcinoma, the importance of describing this entity is in the fact that early diagnosis, awareness and timely management can save the patient from unnecessary surgical intervention and its complications. Tumefactive lesions are considered hallmark of this disease, but rarely abscess may also be the presenting feature. In this article, we describe a 24-year-old female patient of a very unusual case of IgG4-RM presenting as recurrent breast abscess, its successful management and discussion about novel treatment strategies.

Review of IgG4-related disease

IgG4-related disease is a fibrous-inflammatory process related to immunomodulation. The most commonly affected organs are: the pancreas, bile duct, major salivary glands, lacrimal glands, retroperitoneum and lymphatic ducts. In recent decades, this disease has been recognised as a systemic disorder that includes many single organ disorders, previously unrelated and known as independent entities. The common characteristics shared by the different entities that make up the IgG4-related disease are: raised serum IgG4 levels, alterations in the imaging tests with neoplastic-like swelling of the affected organs, specific histopathological characteristics and in immunostaining, as well as good response to treatment with glucocorticoids. In this work, we will review this pathology with a special emphasis on the characteristics of autoimmune pancreatitis, sclerosing cholangitis related to IgG4 and the involvement of the retroperitoneum, mesenterium and the digestive tract.

IgG4-Related Disease of Skull Base: Case Series of 3 Patients with Headache

BACKGROUND

IgG4-related disease (IgG4-RD) is an immune-mediated, systemic, fibroinflammatory disease. IgG4-RD may manifest in almost every part of the human body. Here, we describe 3 patients with a skull base manifestation of IgG4-RD that mimicked malignancy.

CASE DESCRIPTION

Patient 1, a 73-year-old male, presented with a mass in the left nasopharynx and clivus. Patient 2, a 73-year-old male, presented with a mass in the left petrous bone and clivus with involvement of the left jaw joint. Patient 3, a 50-year-old male, presented with a lytic lesion of the clivus and sphenoid bone. All patients complained of headache and hearing loss. Serum IgG4 was normal, and imaging did not show systemic manifestation. Histology established the diagnosis of IgG4-RD. Two patients were treated successfully with prednisolone, hydroxychloroquine, and radiotherapy. One patient is monitored without treatment.

CONCLUSIONS

The described cases emphasize the broad clinical spectrum of IgG4-RD. The diagnostic workup may be challenging, and serum IgG4 may be normal, as demonstrated in these cases. Careful histopathologic examination of the tissues remains essential. Timely diagnosis of IgG4-RD is important to prevent secondary organ damage in patients with active disease.

Untypical autoimmune pancreatitis and pancreatic cancer: differential diagnosis experiences extracted from misdiagnose of two cases

BACKGROUND

Differentiation between pancreatic cancer (PC) and focal form of autoimmune pancreatitis (AIP) is very challenging, with similar clinical presentations, laboratory results and morphologic imagings of US, CT, EUS, MRI, ERCP, PET-CT. Even serum IgG4 and biopsy sometimes cannot give clear-cut differential accurate diagnostis. Considering the totally different management strategy of the two diseases, accurate diagnostic value is urgently needed to remind the clinicians of the rare diagnosis of untypical AIP among frequent PC-suspected patients.

RESULTS

We present 2 laparotomy cases of AIP that had a high similar characteristic to PC and retrospectively extracted the warning signs that may help select untypical AIP in PC-suspected patients.

CONCLUSIONS

We find that mild fluctuating jaundice with abdominal pain, young age, tumor marker of TPS, TPA and diverse results between variable radiological tests can help to differentiate AIP mass from PC, through retrospectively analyzing work-up process of AIP in two patients who underwent laparotomy for suspected PC.

Clinical outcomes and predictive relapse factors of IgG4-related disease following treatment: a long-term cohort study

OBJECTIVES

The aim of this study was to investigate the predictive factors for relapse of IgG4-related disease (IgG4-RD) and observe the long-term clinical outcomes in patients with IgG4-RD.

METHODS

We included in the present analysis 122 patients who were newly diagnosed with IgG4-RD, treated with glucocorticoid (GC) monotherapy or GC and immunosuppressant combination therapy, and followed for at least 3 years. Clinical relapse, response and side effects were recorded.

RESULTS

The cumulative relapse rates of patients in this study were 10.66%, 22.95% and 27.87% at 12, 24 and 36 months, respectively. Complete drug withdrawal was an independent risk factor for disease relapse. Higher serum IgG4 concentrations, involvement of more organs, higher IgG4 RI scores and elevation of eosinophils at baseline were closely associated with disease relapse. Re-elevation of serum IgG4 concentrations and low GC maintenance dosage during the follow-up period were significantly associated with clinical relapse. The GC dosage should be more than 6.25 mg day^-1 as monotherapy during the maintenance stage; moreover, combining with immunosuppressants can reduce the GC dosage. Adding GC or immunosuppressants for patients with re-elevation of serum IgG4 levels could prevent later disease relapse. No serious complications were noted during long-term follow-up.

CONCLUSIONS

The combination of GC with immunosuppressants was more effective than GC monotherapy during the steroid tapering and maintenance stages. Higher serum IgG4 levels, involvement of more organs, higher IgG4 RI scores, history of allergy, eosinophil elevation at baseline, re-elevation of serum IgG4 levels and lower GC maintenance dosage at follow-up might be predictive of relapse.

Bilateral orbital involvement of IgG4-related disease detected on 18F-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography: A Clinical Case Report

RATIONALE

IgG4-related disease (IgG4-RD) is a systemic immune-mediated fibro-inflammatory condition, which could involve multiple structures, including the pancreas, salivary glands, and lymph nodes. However, cases of IgG4-RD involving the bilateral orbits, salivary glands, submandibular glands, lymph nodes, and prostate are rare.

PATIENT CONCERNS

A 51-year-old man complaining of bilateral exophthalmos, reduced vision, and weight loss of 15 kg over 2 years presented to our department for evaluation.

DIAGNOSES

Based on the elevated serum IgG4 level, postoperative pathology, and the features of F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT), which revealed diffuse increased FDG uptake in many structures, he was diagnosed with IgG4-related disease involving the bilateral orbits, salivary glands, submandibular glands, lymph nodes, and prostate.

INTERVENTIONS

Because of the significant bilateral proptosis and exposure keratoconjunctivitis in the right eye, bilateral soft-tissue masses located in the orbits were resected, and the patient was started on oral methylprednisolone with gradual tapering.

OUTCOMES

The patient's symptoms gradually relieved after the operation and glucocorticoid therapy. Four months later, cranial axial CT revealed remarkable narrowing of soft-tissue masses in the bilateral orbits, and his serum IgG4 level reduced sharply.

LESSONS

IgG4-RD should be considered in cases of diffuse FDG uptake in the bilateral orbits, salivary glands, submandibular glands, lymph nodes, and prostate on PET/CT.