Comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), 2011

Polycystic subdural hygroma associated with immunoglobulin G4-related intracranial hypertrophic pachymeningitis: a case report

Background

Recent studies have examined hypertrophic pachymeningitis as an IgG4-RD. However, there are no reports of immunoglobulin G4 (IgG4)-related hypertrophic pachymeningitis with polycystic subdural hygroma.

Case presentation

A 56-year-old man presented to the hospital with complaints of a persistent, pulsatile, occipital headache and general malaise. Magnetic resonance imaging of the brain revealed hypertrophic pachymeningitis with polycystic subdural hygroma and hematoma. Based on the dural biopsy findings and exclusion of other diseases, the patient was diagnosed with immunoglobulin G4 (IgG4)-related hypertrophic pachymeningitis. IgG4-related diseases may cause subdural hygroma more commonly than other diseases that cause hypertrophic pachymeningitis.

Conclusions

This is the first case report discussing polycystic subdural hygroma and hematoma with IgG4-related hypertrophic pachymeningitis.

IgG4-related kidney disease: experience from a Mexican cohort

To evaluate the clinical/serological phenotype and outcomes of IgG4-related kidney disease. Case series of IgG4-related kidney disease from a cohort of 69 patients with IgG4-related disease. We defined kidney involvement as the presence of at least one of the following conditions: (A) laboratory parameters of kidney injury (proteinuria and/or elevated creatinine levels and/or hematuria); and/or (B) contrast-enhanced computed tomography features (multiple low-density lesions and/or nephromegaly and/or hypovascular solitary mass and/or renal pelvic lesion and/or perinephric lesions). We identified 17 patients with kidney involvement (24.6%), with a mean age of 53.6 ± 11.3 years; thirteen (76.5%) were male. Six patients fulfilled the laboratory criteria, six the imaging criteria, and five both. Five patients had a renal biopsy, the main histopathological diagnosis being IgG4 tubulointerstitial nephritis. Sixteen patients received glucocorticoids and 12 also immunosuppressors and/or biologics. Sixteen patients presented either total or partial renal remission at a median follow-up of 26 months, while one patient developed end-stage renal disease. Patients with kidney disease, as opposed to patients without kidney involvement, had a higher number of involved organs, higher IgG4-related disease responder index and IgG4 and IgG1 serum levels, higher prevalence of rheumatoid factor, and lower C3 and C4 levels. Our study emphasizes the systemic nature of IgG4-related disease, highlighting that renal involvement is usually present in a subset of patients with multisystemic disease, high IgG1 and IgG4 levels, and hypocomplementemia. Key Points • IgG4-RKD presents at a younger age in Mexican mestizo patients. • IgG4-RKD presents with proteinuria and kidney injury or as an asymptomatic imaging finding. • IgG4-RKD presents in the context of multisystemic disease, hypocomplementemia, and high IgG1 and IgG4 levels.

Association of circulating SLAMF7+Tfh1 cells with IgG4 levels in patients with IgG4-related disease

BACKGROUND

Follicular helper CD4+ T (Tfh) cells have a critical role in IgG4 production by B cells in IgG4-related disease (IgG4-RD). Recent studies including ours showed that SLAMF7+CD4+ T cells are an important pathological driver of IgG4-RD. In this study, we have sought to elucidate a relationship between helper CD4+ T (Th), particularly Tfh, cells and SLAMF7+ CD4+ T cells in IgG4-RD.

RESULTS

The patients with IgG4-RD enrolled in this study were aged 66 ± 12 years and their titers of serum IgG4 were 372 ± 336 mg/dl. Th1 cells, activated circulating Tfh1 (cTfh1), and activated cTfh2 cells increased in IgG4-RD. SLAMF7 was mainly expressed on Th1 and cTfh1, but not cTfh2, cells in the patients. SLAMF7+ cTfh1 cells were PD-1/CD28 double-positive, whereas SLAMF7+ Th1 cells were CD28 negative. Positive correlations were noted between serum IgG4 levels and the number of activated cTfh2 cells and SLAMF7+ cTfh1 cells, but not SLAMF7+ Th1 cells. Intriguingly, among cTfh1 cells, activated SLAMF7+ cTfh1 cells were high producers of IL-10 along with IL-21. Blimp-1, but not Bcl-6, mRNA was expressed at high levels in activated SLAMF7+ cTfh1 cells. In addition to CD4+ T cells, the frequency of SLAMF7+ fraction was higher in memory B cells than naïve B cells in patients with IgG4RD. Finally, upon stimulation via B-cell receptor and CD40, Tfh1-associated cytokines, IL-21 and IFN-γ, most significantly induced SLAMF7 expression in memory B cells.

CONCLUSIONS

Together, these results suggest that circulating SLAMF7+ Tfh1 cells, along with Tfh2 cells, play a pathologic role in IgG4 production in IgG4-RD.

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.

IgG4-related aortitis/periaortitis and periarteritis: a distinct spectrum of IgG4-related disease

BACKGROUND

Large vessels could be involved in immunoglobulin (Ig)-G4-related disease (IgG4-RD). This study aimed to clarify the clinical features and evaluate the treatment efficacy for IgG4-RD with aortitis/periaortitis and periarteritis (PAO/PA).

METHODS

This study prospectively enrolled 587 patients with IgG4-RD with a follow-up time of more than 6 months. The distribution of IgG4-related PAO/PA was classified into four types: type 1, thoracic aorta; type 2a, abdominal aorta; type 2b, abdominal aorta and iliac artery; type 2c, iliac artery; type 3, thoracic and abdominal aorta; and type 4, other arteries. Patient's demographic data, clinical characteristics, laboratory parameters, and treatment efficacy were analyzed.

RESULTS

Of 587 IgG4-RD patients, 89 (15.2%) had PAO/PA. The average age was 58.3 ± 11.1 years, with male predominance (85.4%). Vessels affected were as follows: abdominal aorta (83.1%), iliac artery (70.8%), thoracic aorta (13.5%), and other vessels (13.5%). The most prevalent distribution type of IgG4-related PAO/PA was type 2b, with 74 (83.1%) patients, followed by type 2a, type 2c, type 3, and type 1. Fifty-five (61.8%) PAO/PA patients had hydronephrosis, with renal insufficiency occurring in 43 (48.3%), and 31 (34.8%) PAO/PA patients had D-J stent drainage due to severe ureteral obstruction. After treatment with a glucocorticoid and immunosuppressants, 82% patients achieved remission with shrinking of the perivascular mass by more than 30%.

CONCLUSIONS

IgG4-RD with PAO/PA was distinct from non-PAO/PA in demographic features, organ involvement distribution, inflammatory markers, and serum IgG4 and IgE. The most common affected vessel was the abdominal aorta, and most patients responded well with treatment.

IgG4-related disease with elevated adenosine deaminase in pleural effusion diagnosed clinically using thoracoscopy under local anesthesia and FDG-PET-CT

In general, we have to assume tuberculous pleurisy when a patient presents with pleural effusion and elevated adenosine deaminase (ADA). However, other diseases need to be considered, including immunoglobulin (Ig)G4-related disease (IgG4-RD). This case involved a 65-year-old asymptomatic man with right pleural effusion showing elevated ADA. He had no articular findings or rashes. Results were negative for all autoantibodies. Pleura, mediastinal lymph nodes, and areas around the aorta and vertebra showed high uptake of ¹⁸F-fluorodeoxyglucose (FDG) on positron-emission tomography-computed tomography (PET-CT). These findings were specific for IgG4-RD. Based on the results of FDG-PET-CT, we performed thoracoscopy under local anesthesia and bronchoscopy. Pleural biopsy and culture, and other examinations including sputum and blood yielded negative findings for tuberculous pleurisy. A pleural biopsy specimen showed IgG4-positive plasma cells and fibrosis without obliterative phlebitis or storiform fibrosis, and serum IgG4 was also high. The ratio of IgG4-to IgG-positive plasma cells was under 40%, and >10 IgG4-positive cells were seen in high-power fields. This case was classed as ‘possible IgG4-RD’ on the comprehensive diagnostic criteria for IgG4-RD, but did not meet the diagnostic criteria for IgG4-related respiratory disease. Prednisolone proved effective against the pleural effusion. We therefore clinically diagnosed IgG4-RD with pleural effusion based on the 2019 classification criteria for IgG4-RD in the United States. Although few cases of IgG4-RD with pleural effusion have been reported, this disease needs to be considered among the differential diagnoses for high-ADA pleural effusion. FDG-PET-CT and thoracoscopy under local anesthesia may be helpful for diagnosis.

•

ImmunoglobulinG4-related disease (IgG4-RD) with pleural effusion is rare.

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We should assume IgG4-RD as one of the differential diagnoses of pleural effusion with high level of adenosine deaminase.

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Thoracoscopy under local anesthesia and 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET-CT) may be useful as an adjunctive tool for making a diagnosis of IgG4-RD.

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We could diagnosed as IgG4-RD with pleural effusion based on findings of FDG-PET-CT and thoracoscopy, and the responsiveness to prednisolone.

Abundant a proliferation-inducing ligand (APRIL)-producing macrophages contribute to plasma cell accumulation in immunoglobulin G4-related disease

Background

This study aimed to investigate the contribution of a proliferation-inducing ligand (APRIL), a member of the tumor necrosis factor (TNF) superfamily implicated in plasma cell survival, to the development of plasma cell–rich lesions in immunoglobulin G4–related disease (IgG4-RD).

Methods

We performed immunohistochemical staining for APRIL with Stalk-1 and Aprily-8 antibodies specifically recognizing APRIL-producing cells and secreted APRIL, respectively, in renal and submandibular lesions of IgG4-RD in comparison with those of Sjögren’s syndrome and sialolithiasis.

Results

Numerous Stalk-1-positive APRIL-producing cells were detectable in lesions of IgG4-RD. These cells, identified as CD163-positive M2 macrophages, secreted APRIL that distributed close to and even on infiltrating plasma cells. In contrast, APRIL-producing cells and the secreted form of APRIL were rarely detectable in lesions of Sjögren’s syndrome or sialolithiasis. Notably, APRIL expression decreased concomitantly with the level of plasma cell infiltration after successful glucocorticoid treatment.

Conclusions

Abundant infiltration into tissue lesions of APRIL-producing M2 macrophages and retention of secreted APRIL in plasma–cell–rich areas support a role for APRIL in the pathogenesis of plasma cell–rich lesions in IgG4-RD.

Thymus and Activation-regulated Chemokine as a Biomarker for IgG4-related Disease

High serum concentrations of thymus and activation-regulated chemokine (TARC) are observed in allergic diseases such as atopic dermatitis and bronchial asthma. Frequent allergic symptoms have been reported in patients with IgG4-related disease (IgG4-RD). We investigated the pathogenic role of TARC as a biomarker in IgG4-RD patients. We evaluated the serum concentrations of TARC from 29 IgG4-RD patients, 28 primary Sjögren syndrome (pSS) patients, and 23 healthy controls (HCs) by enzyme-linked immunosorbent assay (ELISA). We analyzed the correlations between the TARC concentrations and the subjects’ clinical parameters. To investigate the biological effect of TARC on the pathogenesis of IgG4-RD, we evaluated the in vitro induction of plasmablasts from IgG4-RD patients by TARC. The serum concentrations of TARC in the IgG4-RD patients were significantly higher than those of the pSS patients and HCs. The serum TARC concentration of the IgG4-RD group was positively correlated with the IgG4-RD responder index (IgG4-RD RI) score and with the number of organs involved, but it was not correlated with the serum IgG4 level or eosinophil number in the IgG4-RD patients’ peripheral blood. The patients who had lung involvement had higher serum TARC concentrations. In vitro, TARC clearly induced the formation of plasmablasts from the IgG4-RD patients’ peripheral blood mononuclear cells. Collectively, our data suggest that a systemic increment of TARC may contribute to the development of IgG4-RD through an aberrant induction of plasmablasts.

An Overlapping Case of IgG4-Related Disease and Systemic Lupus Erythematosus

We are reporting a case of a 63-year-old Chinese female who presented to the rheumatology clinic with positive antinuclear antibody and unintentional weight loss along with lymphadenopathy. Further workup revealed eosinophilia, elevated anti–double stranded DNA, serum protein, and serum IgG4 (immunoglobulin G4). The patient was diagnosed with systemic lupus erythematosus. Due to the raised IgG4 level along with eosinophilia and diffuse lymphadenopathy, IgG4-related systemic disease was suspected. It was confirmed with IgG4 staining on lymph node biopsy. Our case is presenting the fact that systemic lupus erythematosus and IgG4-related disease can be present in the same patient with multiple overlapping features making accurate diagnosis challenging.

Nationwide epidemiological survey of autoimmune pancreatitis in Japan in 2016

BACKGROUND

To further clarify the clinico-epidemiological features of autoimmune pancreatitis (AIP) in Japan, we conducted the fourth nationwide epidemiological survey.

METHODS

This study consisted of two stage surveys; the number of AIP patients was estimated by the first survey and their clinical features were assessed by the second survey. We surveyed the AIP patients who had visited hospitals in 2016.

RESULTS

The estimated number of AIP patients in 2016 was 13,436, with an overall prevalence rate of 10.1 per 100,000 persons. The estimated number of newly diagnosed patients was 3984, with an annual incidence rate of 3.1 per 100,000 persons. Compared to the 2011 survey, both numbers more than doubled. We obtained detailed clinical information of 1474 AIP patients. The male-to-female sex ratio was 2.94, the mean age was 68.1, and mean age at diagnosis was 64.8. At diagnosis, 63% patients were symptomatic and nearly half of them presented jaundice. Pancreatic cysts were found in 9% of the patients and calcifications in 6%. Histopathological examination was performed in 64%, mainly by endoscopic ultrasonography-guided fine needle aspiration. Extra-pancreatic lesions were detected in 60% of the patients. Eighty-four % patients received the initial steroid therapy, and 85% received maintenance steroid therapy. Kaplan-Meier analysis revealed that the relapsed survival was 14% at 3 years, 25% at 5 years, 40% at 10 years, and 50% at 15 years. Mortality was favorable, but pancreatic cancer accounted for death in one quarter of fatal cases.

CONCLUSION

We clarified the current status of AIP in Japan.

IgG4-related Sclerosing Cholangitis Mimicking Cholangiocarcinoma Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration

A 58-year-old man was referred for obstructive jaundice. Imaging modalities revealed the presence of multiple pancreatic tumors and the stenosis of the middle common bile duct due to a hypoenhanced localized tumor. The multiple pancreatic tumors were histopathologically diagnosed as autoimmune pancreatitis by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). To differentiate between IgG4-related sclerosing cholangitis (IgG4-SC) and cholangiocarcinoma, we diagnosed the biliary tumor as IgG4-SC by EUS-FNA because of insufficient pathological materials obtained in a transpapillary manner. We herein report a case of IgG4-SC diagnosed by EUS-FNA.

IgG4-Related Disease coexisting with Behçet's Disease

We describe a case of Immunoglobulin G4-related disease (IgG4-RD) coexisting with Behçet’s disease. A 49-year-old man, with a diagnosis of Behçet’s Disease for 15 years who was found to have an acute kidney injury. His investigations revealed an elevated IgG4 level and the abdominal computerized tomography showed a retroperitoneal mass, which was diagnosed to be IgG4-RD based on histology. The patient showed symptomatic and radiological improvement after starting high dose steroid for 1 month followed by a maintenance dose. Our case report suggested that the two diseases arose separately.

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.

Symptomatic IgG4-Related Prostatitis Simultaneously Diagnosed with Aggressive Prostate Cancer

IgG4-related disease is a systemic fibroinflammatory disorder that occasionally affects the prostate. It is usually considered that patients with IgG4-related disease are at high risk of developing malignancies. A 71-year-old man presented to our hospital with a chief complaint of urinary retention. Prostate biopsy revealed concomitant IgG4-related prostatitis and prostate cancer. IgG4-related prostatitis was a possible cause of urinary retention, and the aggressive nature of prostate cancer was the cause of the patient's death 2 years after diagnosis. This is the fourth case report of prostate cancer accompanied by IgG4-related prostatitis; however, there have been no reports of the two diseases coexisting with high clinical significance. Our case report indicates that patients diagnosed with IgG4-related prostatitis should be carefully followed up considering the risk of prostate cancer.

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.

Interstitial pneumonia with autoimmune features that met the proposed diagnostic criteria for IgG4-related respiratory disease

We held a multidisciplinary discussion (MDD) about a 61-year-old woman who had an interstitial lung disease (ILD) without extrathoracic lesions that met the classification criteria for interstitial pneumonia with autoimmune features (IPAF) and the proposed diagnostic criteria for immunoglobulin G4 (IgG4)-related respiratory disease (IgG4-RRD). Clinically, the marked progression of lung-limited diffuse lesions was consistent with IPAF. Serum IgG4 and rheumatoid factor levels simultaneously increased and did not contribute to a diagnosis. Pathologically, the significant hyperplasia of lymphoid follicles was consistent with rheumatoid arthritis (RA)-associated ILD. Pulmonary venous occlusions by intimal fibrosis and intimal thickening were not important because these occlusions are found in IgG4-related lung disease (IgG4-RLD) and also in IPAF or ILDs related to connective tissue diseases (CTDs). Radiologically, fibrosing shadows that remained in the lung periphery after treatment were compatible with RA-associated chronic ILD. We concluded that the present case was IPAF that met the proposed diagnostic criteria for IgG4-RRD.

Immunoglobulin G4-related chronic sclerosing sialadenitis: An emerging entity

Chronic sclerosing sialadenitis is associated with the immunoglobulin G4 (IgG4)-related disease (RD) spectrum. IgG4-RD is a newly recognized immunomediated fibroinflammatory condition characterized by several features: a tendency to form tumefactive lesions at multiple sites, lymphoplasmacytic infiltrate, fibrosis and obliterative phlebitis. Often but not always, the serum IgG4 concentrations are also elevated. Immunohistochemistry for IgG4 is helpful to clinch the diagnosis. Here, we describe a case of 65-year-old male with IgG4-related chronic sclerosing sialadenitis of the s ubmandibular gland. We have discussed the histopathological criteria to diagnose this entity.

Characteristics of pleural effusion in IgG4-related pleuritis

Here we describe the case of a 78-year-old man with respiratory failure and right pleural effusion. Computed tomography showed right pleural effusion with pleural calcification, tumor-like shadows induced by passive atelectasis, and enlarged mediastinal lymph nodes. Positron emission tomography showed right pleural thickening, rounded atelectasis, and enlarged mediastinal lymph nodes, without fluid accumulation in other organs. The pleural effusion showed lymphocyte-dominated exudates with elevated adenosine deaminase (ADA) levels. Tuberculous pleuritis was suspected, but thoracoscopic pleural biopsy revealed lymphoplasmacytic infiltration and fibrosis, with 10 immunoglobulin G4 (IgG4)-positive plasma cells/high-power field, and IgG4/IgG ratio of 40%. IgG4 concentrations in serum and right pleural effusion were 929 and 1120 mg/dL, respectively. The patient was diagnosed with IgG4-related pleuritis without other systemic manifestations, and reduction in right pleural effusion was confirmed by corticosteroid therapy. IgG4-related disease is typically a systemic disease causing lymphoplasmacytic inflammation in multiple organs. We describe a rare form of IgG4-related pleuritis showing pleural effusion with no other systemic manifestation.

Sclerosing Mesenteritis Mimicking IgG4-related Disease

A 72-year-old man was followed as an outpatient at our hospital for 6 years after surgery for small cell carcinoma of left adrenal gland origin. Follow-up abdominal computed tomography showed a 6-cm mass in the left lower mesentery. The patient underwent open laparotomy. The histological diagnosis was sclerosing mesenteritis. The previous specimens of the left adrenal mass were then re-examined with a microscope, and panniculitis was found around the small cell carcinoma. Both lesions were histologically similar to IgG4-related disease (RD), but they did not completely meet the diagnostic criteria of IgG4-RD clinically or histologically.

Disease Severity Linked to Increase in Autoantibody Diversity in IgG4-Related Disease

OBJECTIVE

Four autoantigens have been described recently in IgG4-related disease (IgG4-RD): prohibitin, annexin A11, laminin 511-E8, and galectin-3. However, no external validation has been performed, and the possibility that some individuals break tolerance to more than 1 autoantigen has not been explored. We undertook this study to evaluate the relative frequencies of antibody responses against these autoantigens in order to explore the role of adaptive immune response in IgG4-RD.

METHODS

Autoantibody responses against prohibitin, annexin A11, and laminin 511-E8 were measured among a clinically diverse cohort of IgG4-RD patients (n = 100) using enzyme-linked immunosorbent assays. Autoantibody responses were correlated with disease severity and organ distribution.

RESULTS

The frequencies of IgG4 autoantibody responses against prohibitin (10%), annexin A11 (12%), and laminin 511-E8 (7%) were not significantly different from those of controls. A portion of the cohort (n = 86) had been analyzed previously at our center for anti-galectin-3 antibody responses, with 25 patients (29%) having IgG4 anti-galectin-3 antibodies. Of these 86 patients, 32 (37%) had IgG4 antibodies to ≥1 of the 4 autoantigens and 12 (14%) showed reactivity with ≥2 of the tested antigens. The subset of patients with ≥2 autoantibodies had higher total levels of IgG1, IgG2, IgG4, and C-reactive protein, were more commonly hypocomplementemic, and were more likely to have visceral organ involvement.

CONCLUSION

Antibodies against prohibitin, annexin A11, and laminin 511-E8 were found in only a small portion of patients with IgG4-RD. A subset of IgG4-RD patients, however, had IgG4 antibodies against ≥2 autoantigens. These patients presented with robust IgG subclass elevations, complement consumption, and visceral organ involvement. This broader break in immunologic tolerance in IgG4-RD was associated with more severe disease.

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.

A comparison of the features of fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) between IgG4-related disease with bilateral hilar lymphadenopathy and sarcoidosis

We aimed to show the differentiation of the degree and distribution on Fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) between patients with immunoglobulin G4-related disease (IgG4-RD) and sarcoidosis, though both diseases frequently show bilateral hilar lymphadenopathy (BHL). The clinical records were retrospectively reviewed in 25 patients with IgG4-RD with BHL and 15 patients with sarcoidosis (stage I–II) diagnosed at Shinshu University Hospital. All patients underwent FDG-PET at Aizawa Hospital from January 2004 to December 2015. The FDG accumulation pattern and maximum standardized uptake value (SUVmax) of the hilar lymph nodes were compared between the two groups. The IgG4-RD group (21 men; median age 69 years) showed a significant male predominance and older age compared with the sarcoidosis group (3 men, median age 55.4 years). The IgG4-RD group showed a significantly higher incidence of FDG accumulation in the lachrymal gland, submandibular gland, pancreas, prostate and periurethral and periarterial regions compared with the sarcoidosis group. In contrast, the sarcoidosis group showed a significantly higher incidence of FDG accumulation in the supraclavicular and abdominal lymph nodes, muscle and soft tissues compared with the IgG4-RD group. Furthermore, the SUVmax of the hilar lymph nodes was significantly higher in the sarcoidosis group (median 7.20) than in the IgG4-RD group (median 4.20, p=0.002). In conclusion, significant differences were observed in the FDG accumulation patterns and SUVmax values of the hilar lymph nodes between IgG4-RD with BHL and sarcoidosis, although both diseases develop through the lymphatic routes of the lungs and are frequently associated with BHL.

Peribiliary glands: development, dysfunction, related conditions and imaging findings

Peribiliary glands are minute structures that are distributed along the intrahepatic large bile ducts, extrahepatic bile duct, and cystic duct. These glands regulate many physiological functions, such as enzyme secretion. Pancreatic exocrine tissues and enzymes are often observed in peribiliary glands; thus, peribiliary glands are involved in enzyme secretion. As such, these glands can be affected by conditions such as IgG4-related sclerosing cholangitis based on commonalities with their pancreatic counterparts. Cystic changes in peribiliary glands can occur de novo, as part of a congenital syndrome, or secondary to insults such as alcoholic cirrhosis. Biliary tree stem/progenitor cells have recently been identified in peribiliary glands. These cells are involved in turnover and regeneration of biliary epithelia as well as in sclerosing reactions in some pathological conditions, such as primary sclerosing cholangitis and hepatolithiasis. Notably, hepatolithiasis is involved in mucin secretion by the peribiliary glands. Additionally, these cells are associated with the manifestation of several neoplasms, including intraductal papillary neoplasm, cystic micropapillary neoplasm, and cholangiocarcinoma. Normal peribiliary glands themselves are particularly small structures that cannot be recognized using any available imaging modalities; however, these glands are closely associated with several diseases, as mentioned above, which have typical imaging features. Therefore, knowledge of the basic pathophysiology of peribiliary glands is helpful for understanding biliary diseases associated with the peribiliary glands.

Clinical implications of elevated serum interleukin-6 in IgG4-related disease

Introduction

Some patients with IgG4-related disease (IgG4-RD) exhibit elevated serum interleukin (IL)-6 with excessive inflammatory reactions or with repeating relapse. To date few reports pertaining to clinical implications of elevated serum IL-6 in IgG4-RD patients have been published. The aims of the current retrospective study were to investigate the clinical implications of elevated serum IL-6 in IgG4-RD patients, and to examine whether IL-6 can predict the activity and/or relapse of the disease.

Materials and methods

We examined the clinical picture at the onset of 43 patients who were diagnosed with IgG4-RD in our hospital and were able to measure serum IL-6 before steroid treatment.

Results

The median level of serum IL-6 was 2.2 pg/mL. There was a significant correlation between IL-6 and C-reactive protein (CRP) level (r = 0.397, p = 0.008), hemoglobin level (r = -0.390, p = 0.010) and albumin level (r = -0.556, p < 0.001). When 43 patients were divided into two groups by using a cut-off IL-6 of 4 pg/mL, the high IL-6 group showed higher age, lower albumin, higher CRP and higher aspartate aminotransferase (AST) (age p = 0.014, albumin p = 0.006, CRP p <0.001, AST p = 0.009). Hepatic swelling and splenomegaly were significantly more prevalent in the high IL-6 group than it was in the low IL-6 group (liver p < 0.001, spleen p = 0.020). Biliary tract involvement tended to admit more in the high IL-6 group (p = 0.060).

Conclusion

Serum IL-6 level at the onset of IgG4-RD may be significantly correlated with clinical inflammatory parameters and it may also be associated with involvement of the bile duct, liver, and spleen.

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-type Multiple Myeloma with Diffuse Enlargement of the Thyroid Requiring Differentiation from IgG4-related Disease

We herein report a 65-year-old man with elevated serum IgG4 levels, enlarged thyroid, and renal dysfunction, mimicking IgG4-related disease (IgG4-RD). The definitive diagnosis of IgG4-RD was not established because a tissue biopsy revealed no IgG4-positive cell infiltration or fibrosis. The presence of an M peak in the β fraction, Bence Jones protein in urine, and progressive anemia suggested multiple myeloma (MM). The κ/λ ratio was >100, tumor plasma cells were present at >20% in bone marrow, and immunostaining revealed IgG4-positive plasma cells; therefore, he was diagnosed with IgG4-type MM. Patients with elevated IgG4 levels with no significant mass lesions should undergo systemic examinations to exclude malignancy.

IgG4-Related Disease Manifesting as Hypocomplementemic Tubulointerstitial Nephritis: A Rare Case Report and Literature Review

Immunoglobulin G4-related disease (IgG4-RD) is a chronic fibrosing inflammatory systemic disorder that has been recognized relatively recently in the medical literature. Little is known about the exact disease pathogenesis and epidemiology. IgG4-RD may be asymptomatic or may have minimal symptoms or involve multiple organs with overt symptoms. The different phenotypes of IgG4-RD can lead to delayed or incorrect diagnosis. We report the case of a 66-year-old male with coal worker's pneumoconiosis who presented with progressive kidney disease and was diagnosed with tubulointerstitial nephritis due to IgG4-RD. The patient was noted to have progressive kidney disease, skin involvement, worsening interstitial lung disease, complete vision loss in the left eye, and retroperitoneal fibrosis. Serologic workup revealed elevated inflammatory markers, IgG4 and IgG1 levels, and hypocomplementemia. A tissue biopsy helped us establish a definitive diagnosis of IgG4-RD and initiate treatment with glucocorticoids to prevent further progression of kidney disease and other end-organ damage.

Consideration concerning similarities and differences between ANCA-associated vasculitis and IgG-4-related diseases: case series and review of literature

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and immunoglobulin G4-related diseases (IgG4-RD) are regarded as entirely different disease types with different etiological mechanisms. However, we experienced two cases that had clinical features of both AAV and IgG4-RD. The first case is an 81-year-old woman who showed periaortitis and retroperitoneal fibrosis and periarteritis with elevation of myeloperoxidase-anti-neutrophil cytoplasmic antibody and IgG4 levels. The second case is a 63-year-old woman who had dura mater, ear, nose, lung, and kidney involvement with serum negative for ANCA and elevated IgG4. Renal biopsy revealed tubulointerstitial nephritis involving IgG4⁺ plasma cells (IgG4⁺/IgG⁺ cell ratio of ≥ 40%). On the other hand, lung biopsy showed features of granulomatosis with polyangiitis (GPA). These two cases suggested that AAV and IgG4-RD might overlap. To investigate the similarities and differences between AAV and IgG4-RD, we retrospectively analyzed 13 cases of typical GPA, a subtype of AAV, and 13 cases of typical IgG4-RD at our hospital for comparison of clinical features and found some differences that can be useful in the differential diagnosis between the two diseases. Although AAV and IgG4-RD are distinguishable based on characteristic findings in many cases, the diagnosis can be unclear in rare cases, in which clinicians should consider possible coexistence of AAV and IgG4-RD when performing further workup. Here, we discuss the similarities and differences between AAV and IgG4-RD on the basis of our results and past literature.

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.)

A Case of Ruptured Immunoglobulin G4-Related Periaortitis

An 80-year-old man had high serum immunoglobulin G4 (IgG4) concentration and fibrous thickening of the soft tissue mass surrounding the region from the abdominal aorta to the bilateral iliac arteries, suggestive of IgG4-related periaortitis. He presented to our emergency department with sudden-onset abdominal pain and lumbago. Computed tomography revealed a ruptured abdominal aorta. He was a poor candidate for open surgery due to his hostile abdomen. Therefore, endovascular aneurysm repair was performed. No consensus about the surgical indication for IgG4-related arterial disease has been reached yet. We believe that a novel indicator is needed for this disease.

Disruption of tight junction structure contributes to secretory dysfunction in IgG4-related sialadenitis

IgG4-related sialadenitis (IgG4-RS) is a chronic fibro-inflammatory disease characterized by swelling of salivary glands and varying degrees of xerostomia. Tight junctions (TJs) play an essential role in maintaining secretory function by regulating the paracellular flow of ions and water. However, whether TJs are altered and contribute to the hyposecretion in IgG4-RS is not fully understood. Here, a total of 399 differentially expressed proteins were identified in IgG4-RS submandibular glands (SMGs) and enriched in the regulation of actin cytoskeleton and the salivary secretion. Real-time PCR results showed that the mRNA levels of claudin-3, -4, -6, -7, -8, -10, -12, occludin, and ZO-1 were significantly lower, whereas claudin-1 and -5 were higher in IgG4-RS SMGs. Immunohistochemical and immunofluorescence staining revealed that claudin-1, -3, -4, occludin, and ZO-1 were mainly distributed at apicolateral membranes in acini and ducts of SMGs from controls, whereas claudin-1 protein intensity at apicolateral membrane was elevated, while the staining of claudin-3, -4, and ZO-1 were reduced in IgG4-RS SMGs. Occludin was dispersed into cytoplasm of acini and ducts in SMGs of patients. Among them, claudin-3 and ZO-1 protein levels were positively correlated with saliva flow rate. Furthermore, the decreased fluorescence intensity of F-actin at peri-apicolateral membranes and the loss of ZO-1 staining at the same location were observed in acinar and ductal cells of IgG4-RS SMGs, which might be responsible for disorganization of TJ complex. Taken together, these findings indicate that the integrity of TJ complex of SMGs is impaired and might contribute to hyposalivation of IgG4-RS patients.

High-throughput sequencing of CD4+ T cell repertoire reveals disease-specific signatures in IgG4-related disease

Background

CD4⁺ T cells play critical roles in the pathogenesis of IgG4-related disease (IgG4-RD). The aim of this study was to investigate the TCR repertoire of peripheral blood CD4⁺ T cells in IgG4-RD.

Methods

The peripheral blood was collected from six healthy controls and eight IgG4-RD patients. TCR β-chain libraries of CD4⁺ T cells were constructed by 5′-rapid amplification of cDNA ends (5′-RACE) and sequenced by Illumina Miseq platform. The relative similarity of TCR repertoires between samples was evaluated according to the total frequencies of shared clonotypes (metric F), correlation of frequencies of shared clonotypes (metric R), and total number of shared clonotypes (metric D).

Results

The clonal expansion and diversity of CD4⁺ T cell repertoire were comparable between healthy controls and IgG4-RD patients, while the proportion of expanded and coding degenerated clones, as an indicator of antigen-driven clonal expansion, was significantly higher in IgG4-RD patients. There was no significant difference in TRBV and TRBJ gene usage between healthy controls and IgG4-RD patients. The complementarity determining region 3 (CDR3) length distribution was skewed towards longer fragments in IgG4-RD. Visualization of relative similarity of TCR repertoires by multi-dimensional scaling analysis showed that TCR repertoires of IgG4-RD patients were separated from that of healthy controls in F and D metrics. We identified 11 IgG4-RD-specific CDR3 amino acid sequences that were expanded in at least 2 IgG4-RD patients, while not detected in healthy controls. According to TCR clonotype networks constructed by connecting all the CDR3 sequences with a Levenshtein distance of 1, 3 IgG4-RD-specific clusters were identified. We annotated the TCR sequences with known antigen specificity according to McPAS-TCR database and found that the frequencies of TCR sequences associated with each disease or immune function were comparable between healthy controls and IgG4-RD patients.

Conclusion

According to our study of CD4⁺ T cells from eight IgG4-RD patients, TCR repertoires of IgG4-RD patients were different from that of healthy controls in the proportion of expanded and coding degenerated clones and CDR3 length distribution. In addition, IgG4-RD-specific TCR sequences and clusters were identified in our study.

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.

Clinical features and outcomes in a cohort of patients with immunoglobulin G4-related disease at a university hospital in Spain

Background

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory, immune-mediated disorder, which characteristically affects the glandular tissue but has the potential to affect any organ.

Methods

We retrospectively reviewed clinical, laboratory, histological characteristics and treatment response during 12 months of follow-up of a cohort of patients with IgG4-RD diagnosed at a tertiary public hospital. Disease activity was assessed by means of the IgG4-RD responder index (IgG4-RD RI).

Results

In all, 15 patients have been diagnosed at our Institution and herein studied (80% men), with a median age of 60.7 years and a mean affectation of 2.8 organs per patient. We identified six patients with definitive diagnosis and nine with possible IgG4-RD, according to the Japanese diagnostic algorithm. IgG4-RD RI decreased from a median of 11.3 at baseline to 4.0 after 6 months and 6.2 after 12 months. Relapse occurred in five patients and was associated with lower cumulative steroid doses. Five patients (33.3%) required additional immunosuppressive (IS) drugs. Five adverse events were seen during follow-up: three infections, one deep vein thrombosis and one gastrointestinal bleeding. One patient died of pneumonia.

Conclusions

IgG4-RD is an inflammatory disease that can affect any organ. Glucocorticoids were an effective first line of treatment; however, this treatment is associated with important adverse events and relapses occurred in patients with low cumulative doses. As an alternative, IS treatment with rituximab could be an interesting option in those patients.

Extranodal Rosai-Dorfman Disease Presenting as a Pericardial Mass and Constrictive Pericarditis

Rosai-Dorfman disease is a rare, idiopathic disorder of histiocyte proliferation. We describe a case of a 59-year-old woman who presented with heart failure symptoms from a large pericardial mass causing constrictive pericarditis. Pathologic findings including immunohistochemistry suggested the diagnosis. She was treated with corticosteroids and improved clinically. (Level of Difficulty: Advanced.)

Activated M2 Macrophages Contribute to the Pathogenesis of IgG4-Related Disease via Toll-like Receptor 7/Interleukin-33 Signaling

Objective

IgG4‐related disease (IgG4‐RD) is a unique inflammatory disorder in which Th2 cytokines promote IgG4 production. In addition, recent studies have implicated the Toll‐like receptor (TLR) pathway. This study was undertaken to examine the expression of TLRs in salivary glands (SGs) from patients with IgG4‐RD.

Methods

SGs from 15 patients with IgG4‐RD, 15 patients with Sjögren's syndrome (SS), 10 patients with chronic sialadenitis, and 10 healthy controls were examined histologically. TLR family gene expression (TLR‐1 through TLR‐10) was analyzed by DNA microarray in the submandibular glands (SMGs). Up‐regulation of TLRs was confirmed in SGs from patients with IgG4‐RD. Finally, the phenotype of human TLR‐7 (huTLR‐7)–transgenic C57BL/6 mice was assessed before and after stimulation with TLR agonist.

Results

In patients with IgG4‐RD, TLR‐4, TLR‐7, TLR‐8, and TLR‐9 were overexpressed. Polymerase chain reaction validated the up‐regulation of TLR‐7 in IgG4‐RD compared with the other groups. Immunohistochemical analysis confirmed strong infiltration of TLR‐7–positive cells in the SGs of patients with IgG4‐RD. Double immunohistochemical staining showed that TLR‐7 expression colocalized with CD163+ M2 macrophages. After in vitro stimulation with a TLR‐7 agonist, CD163+ M2 macrophages produced higher levels of interleukin‐33 (IL‐33), which is a Th2‐activating cytokine. In huTLR‐7–transgenic mice, the focus and fibrosis scores in SMGs, pancreas, and lungs were significantly higher than those in wild‐type mice (P < 0.05). Moreover, the concentration of serum IgG, IgG1, and IL‐33 in huTLR‐7–transgenic mice was distinctly increased upon stimulation with a TLR‐7 agonist (P < 0.05).

Conclusion

TLR‐7–expressing M2 macrophages may promote the activation of Th2 immune responses via IL‐33 secretion in IgG4‐RD.

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.

Different clinical patterns of IgG4-RD patients with and without eosinophilia

It has been reported that patients with IgG4-related disease (IgG4-RD) showed an elevated incidence of eosinophilia. We aim to explore the clinical patterns of IgG4-RD patients with and without eosinophilia. Four hundred and twenty-five IgG4-RD patients referred to Peking Union Medical College Hospital were enrolled. Blood eosinophil count higher than 0.5 × 10⁹/L was defined as eosinophilia. Clinical features of all the participants were collected and analyzed statistically. Eighty-seven patients (20%) with eosinophilia were found. As compared to those with a normal range of blood eosinophil count, male predominance, longer disease duration, increased prevalence of dacryoadenitis, sialadenitis, lymphadenopathy, and skin rash, higher IgG4-RD responder index, more organ involvement and higher levels of serum IgG4 (17.0 g/L vs 6.5 g/L, P < 0.001) was found in patients with eosinophilia. There was no significant difference in the incidence of allergic disease between the two groups. Peripheral eosinophil counts were positively correlated with disease duration, the number of involved organs, IgG4-RD responder index, and serum IgG4. Higher recurrence rate during follow-up period was found in patients with eosinophilia [28.6% (20/70) vs 17.1% (42/245), P = 0.034]. IgG4-RD patients with eosinophilia exhibited different clinical patterns from patients without. Eosinophilia appeared independent of allergies in IgG4-RD.

Cross-sectional pictorial review of IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder characterized by the infiltration of one or more organs with IgG4-positive plasma cells resulting in inflammatory lesions and fibrosis. Although the pancreas is the most commonly affected organ, involvement of extrapancreatic organs is an increasingly recognized manifestation of the disease. Patients may be asymptomatic and serum IgG4 concentrations may be elevated or normal. Treatment consists of glucocorticosteroid treatment, with excellent response. A definitive diagnosis requires histopathology with imaging playing a key role in avoiding treatment delays. This pictorial review will focus on the most current knowledge regarding IgG4-RD including its common and less common manifestations and the roles of multidetector CT, MRI and ultrasound in the diagnosis and management of suspected IgG4-RD. Knowledge of the varied imaging findings of this multi systemic disease is essential for radiologists to avoid misdiagnosis and assist with timely and effective treatment.

IgG4-related disease with tracheobronchial miliary nodules and asthma: a case report and review of the literature

Background

IgG4-related disease (IgG4-RD) is a systemic autoimmune disease that can affect multiple organs of the body. Pulmonary manifestations of IgG4-RD include pulmonary solid nodules, thickening of bronchovascular bundles, interstitial involvement, and ground glass opacities. Here we present a rare case of IgG4-RD with tracheobronchial nodules and review the relevant literature.

Case presentation

A 52-year-old man was admitted to our hospital with a history of intermittent cough for 27 months and recurrent wheezing for 17 months. He had been diagnosed with asthma prior to admission and was responsive to oral prednisone (30 mg/day, with gradual tapering). Bronchoscopy performed 2 years prior to admission showed tracheal and bronchial mucosal hyperemia, edema, and miliary nodules. Pathological tests showed chronic inflammation with focal lymphocytic infiltration in the bronchial mucosa. The patient had recurrent cough and wheezing after prednisone was stopped or the dose reduced. At the time of admission to our hospital, his serum immunoglobulin G4 (IgG4) level had increased to 7.35 g/L. Following bronchoscopy, the IgG4 expression in the bronchial mucosa was compared with that observed during the last two bronchoscopies. Bronchoscopy performed 7 months prior to admission revealed IgG4+ plasma cell infiltration in the bronchial tissue, with > 10 IgG4+ plasma cells per high power field and an IgG4+/IgG+ cell ratio of > 40%. The current bronchoscopy revealed a decrease in IgG4 expression in the bronchial tissue, probably because of the intermittent prednisone treatment. The case fulfilled the comprehensive clinical diagnostic criteria for IgG4-RD. He received prednisone and azathioprine, and he has never developed recurrence.

Conclusions

Our case exhibited three important clinical indication: First, tracheobronchial miliary nodules could be the presentation of IgG4-related disease. Second, IgG4-related disease with pulmonary involvement has close connection with asthma. Last, IgG4-related disease can be very sensitive to prednisone, the infiltration of IgG4 positive plasma cells decreased after prednisone treatment and symptoms significantly improved in our case. In conclusion, we reported the first case of IgG4-RD presenting with miliary nodules on the tracheal and bronchial tube walls combined with asthma. The findings will further our understanding of the characteristics of IgG4-RD.

Laminin 511 is a target antigen in autoimmune pancreatitis

Autoimmune pancreatitis (AIP), a major manifestation of immunoglobulin G4-related disease (IgG4-RD), is an immune-mediated disorder, but the target autoantigens are still unknown. We previously reported that IgG in patients with AIP induces pancreatic injuries in mice by binding the extracellular matrix (ECM). In the current study, we identified an autoantibody against laminin 511-E8, a truncated laminin 511, one of the ECM proteins, in patients with AIP. Anti-laminin 511-E8 IgG was present in 26 of 51 AIP patients (51.0%), but only in 2 of 122 controls (1.6%), by enzyme-linked immunosorbent assay. Because truncated forms of other laminin family members in other organs have been reported, we confirmed that truncated forms of laminin 511 also exist in human and mouse pancreas. Histologic studies with patient pancreatic tissues showed colocalization of patient IgG and laminin 511. Immunization of mice with human laminin 511-E8 induced antibodies and pancreatic injury, fulfilling the pathologic criteria for human AIP. Four of 25 AIP patients without laminin 511-E8 antibodies had antibodies against integrin α6β1, a laminin 511 ligand. AIP patients with laminin 511-E8 antibodies exhibited distinctive clinical features, as the frequencies of malignancies or allergic diseases were significantly lower in patients with laminin 511-E8 antibodies than in those without. The discovery of these autoantibodies should aid in the understanding of AIP pathophysiology and possibly improve the diagnosis of AIP.

Management of Takayasu arteritis: a systematic literature review informing the 2018 update of the EULAR recommendation for the management of large vessel vasculitis

Objective

To collect available evidence on management of large vessel vasculitis to inform the 2018 update of the EULAR management recommendations.

Methods

Two independent systematic literature reviews were performed, one on diagnosis and monitoring and the other on drugs and surgical treatments. Using a predefined PICO (population, intervention, comparator and outcome) strategy, Medline, Embase and Cochrane databases were accessed. Eligible papers were reviewed and results condensed into a summary of findings table. This paper reports the main results for Takayasu arteritis (TAK).

Results

A total of 287 articles were selected. Relevant heterogeneity precluded meta-analysis. Males appear to have more complications than females. The presence of major complications, older age, a progressive disease course and a weaker inflammatory response are associated with a more unfavourable prognosis. Evidence for details on the best disease monitoring scheme was not found. High-quality evidence to guide the treatment of TAK was not found. Glucocorticoids are widely accepted as first-line treatment. Conventional immunosuppressive drugs and tumour necrosis factor inhibitors were beneficial in case series and uncontrolled studies. Tocilizumab failed the primary endpoint (time to relapse) in a randomised controlled clinical trial; however, results still favoured tocilizumab over placebo. Vascular procedures may be required, and outcome is better when performed during inactive disease.

Conclusions

Evidence to guide monitoring and treatment of patients with TAK is predominantly derived from observational studies with low level of evidence. Therefore, higher-quality studies are needed in the future.

IgG4-Related Disease with Esophageal Involvement

We report the case of a 56-year-old man who presented with dysphagia and weight loss. An esophagoduodenoscopy revealed a severe esophageal stricture in the distal esophagus. After surgical resection, the final pathologic analysis revealed that the tumor was comprised of benign-appearing fibroinflammatory cells with an increase and predominance of IgG4-positive plasma cells. He did not, however, have any other symptoms indicative of systemic autoimmune disease or connective tissue disorders. Histologically, abundant infiltration of IgG4-positive plasma cells and lymphocytes was observed. The patient was diagnosed with IgG4-related disease, definitive, with esophageal involvement.

IgG4-related lymphadenopathy masquerading as Hodgkin lymphoma: lessons from a pathologist's desk

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder affecting multiple organ systems. The awareness of this disease has tremendously increased over the last decade leading to effective treatment and decreased morbidity to the patients. Histopathology plays an important role in the diagnosis of IgG4-RD, and definite histologic criteria are proposed in clinically suspected patients. We report a patient with multiple organ system involvements of the salivary gland, lymph node and kidney. IgG4-related lymphadenopathy (IgG4-RL) in this patient was misdiagnosed as nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL). Refractoriness to treatment for NLPHL and subsequent manifestations of renal involvement lead us to the correct diagnosis of this potentially treatable condition. IgG4-RL can mimic reactive proliferation as well as lymphomas. We report the clinical presentation and discuss the problems faced by pathologists in diagnosing IgG4-RL. We believe that awareness of this rare presentation will enhance the knowledge in diagnosing IgG4-RD.

A Case of IgG4-Related Bilateral Palpebral Conjunctivitis

The most common sites of IgG4-related ocular disease are the lacrimal glands, infraorbital nerve, and extraocular muscles. Other ocular adnexal sites are relatively rare. We report a rare case of an 83-year-old man who developed palpebral conjunctivitis following bilateral hypertrophic ectropion of the eyelid. Tissue immunostaining revealed many IgG4-positive plasma cells (67 IgG4/74 IgG cells/high-power field). The serum IgG4 level was 76.9 mg/dL, which was within the normal range. The diagnosis was probable IgG4-related disease. The possibility of IgG4-related disease should be considered in a patient presenting with refractory conjunctivitis and hyperemia or hypertrophy of the lower eyelid.

An unusual presentation of chronic sclerosing sialadenitis of submandibular gland (Kuttner's tumour)

Kuttner's tumour, also known as chronic sclerosing sialadenitis, is a localised form of IgG4 disease which presents as asymptomatic submandibular gland swelling. The diagnosis is usually based on histopathology and immunohistochemistry. A 33-year-old woman presented with acute-onset pain and swelling in the right submandibular region. Clinical examination showed an enlarged submandibular gland, and CT showed a calculus in the Wharton's duct. After treating the acute phase with antibiotics, the patient underwent submandibular gland excision and calculus removal. Histopathology of the specimen showed areas of periductal sclerosis, acinar atrophy and intense lymphoplasmacytic infiltrates with occasional eosinophils. The IgG4 to IgG plasma cell ratio was >40%, suggestive of an IgG4-related disease. The authors have chosen to report this case because of the unusual presentation of IgG4 disease as acute sialadenitis.