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

New biomarkers for the diagnosis of pleural effusion

Background

Persistent undiagnosed effusion is present in approximately 15% of all causes of exudative effusion. Pleural effusion caused by immunoglobulin G4 (IgG4) is a new type of pleural effusion. Tumor markers such as Carcinoembryonic antigen (CEA) may play a role in the diagnosis of malignant pleural effusion. This study aimed to evaluate the use of serum Immunoglobulin G4 and carcinoembryonic antigen in diagnosing pleural effusion.

Methods

This observational descriptive cross-sectional study comprised 89 individuals with exudative pleural effusion who visited the Assiut university hospital's chest department. All patients were examined and asked about their medical history. Also, chest X-ray, MSCT chest, transthoracic ultrasonography, pleural fluid analysis and cytology, serum level of carcinoembryonic antigen, and immunoglobulin G4 were performed. In addition, pleural biopsy, bronchoscopy, and thoracoscopy were performed when required.

Results

In comparison to another diagnosis, the level of serum IgG 4 was observed to be substantially greater in individuals with IgG4-associated effusion (725± 225.45). Patients with malignant mesothelioma (70± 16.24) and metastatic adenocarcinoma (93.52± 19.34) had lower levels of IgG4. In contrast, the serum level of CEA was significantly higher in individuals with malignant mesothelioma (79.50± 29.47) and metastatic adenocarcinoma (68.71± 28.98). Patients with para-pneumonic effusion had a minor serum level of CEA (0.36 ± 0.26). At cutoff point > 152 mg/dl serum IgG-4 had 100% sensitivity and 94% specificity in the diagnosis of IgG4 related pleural effusion with an overall accuracy of 95.3% and area under the curve of 0.97. At the cutoff point > 5 ng/ml serum CEA had 77% sensitivity and 100% specificity in diagnosing malignant pleural effusion with an overall accuracy of 91.1% and area under the curve of 0.88.

Conclusion

Serum IgG4 higher than 152 mg/dl has good diagnostic accuracy in cases of undiagnosed pleural effusion. Carcinoembryonic antigen aids in diagnosing malignant pleural effusion with a cutoff point higher than 5 ng/ml in serum.

Trial registration

ClinicalTrials.gov registration ID NCT03260088

Long-Term Follow-Up in IgG4-Related Ophthalmic Disease: Serum IgG4 Levels and Their Clinical Relevance

(1) Background: To analyze the association between long-term changes in serum IgG4 levels and the clinical course of patients with IgG4-related ophthalmic disease (IgG4-ROD). (2) Methods: Retrospective analysis of 25 patients with IgG4-ROD. (3) Results: Mean age at diagnosis was 60.68 years. Fifty-six percent of patients had bilateral ocular involvement and 32% had systemic associations. The ocular structures involved were the lacrimal gland (76%), orbital soft tissue (36%), extraocular muscle (20%) and infraorbital nerve (20%). According to last follow-up, 9 (36%) patients had normalized IgG4 levels, and 16 (64%) patients had elevated IgG4 levels. Patients with normalized IgG4 levels had better response to initial steroid treatment and attained a significantly lower IgG4 level after treatment (p = 0.002). The highest IgG4 levels were at baseline and disease recurrence, and lowest after initial treatment. At final follow-up, IgG4 levels differed in patients with remission (mean 326.25 mg/dL) and stable disease (mean 699.55 mg/dL). Subgroup analysis was performed in patients with remission, categorized according to whether IgG4 levels were normalized (9 patients) or elevated (10 patients) on last follow up. The elevated group had a higher percentage of bilateral disease, lacrimal gland involvement and recurrence. (4) Conclusions: IgG4-ROD patients with a greater response to initial steroid therapy were more inclined to have normalized IgG4 levels in the long term. Some patients remained in remission despite persistently elevated IgG4 levels, and had regular follow-up without treatment.

A CARE-compliant article: A case report and literature review of IgG4-related lung disease

RATIONALE

IgG4-related lung disease (IgG4-RLD) is an unusual disease, with various clinical manifestations and various chest imaging findings. The patients may have no respiratory symptoms. Therefore, diagnosis is challenging. This can easily cause misdiagnosis and mistreatment.

PATIENT CONCERNS

A 71-year-old male presented with chest pain, cough, and shortness of breath. Plain chest computed tomography scans showed multi-locus nodes at the center of the hilum.

DIAGNOSIS

Percutaneous lung biopsy was performed, and IgG4-RLD was diagnosed.

INTERVENTIONS

Prednisone was orally administered daily.

OUTCOMES

The case's symptoms improved. The patient was discharged from the hospital. After 2 months of reexamination, his symptoms were relieved. Reexamination of the chest computed tomography showed that multi-locus nodes of the lung were obviously absorbed compared with those before.

LESSONS

IgG4-RLD is a rare respiratory disease. It has atypical clinical manifestations and chest images. We report the first case of IgG4-RLD showing multi-locus nodes centered on the hilar, hypertrophic mucosa; as well as a narrow and even occluded lumen.

Multimodality Imaging Evaluation of Coronary IgG4-Related Disease: A "Tumor-Like" Cardiac Lesion

Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated fibro-inflammatory disorder. Coronary IgG4-RD has been scarcely reported and may present as "tumor-like" lesions. These pseudo-masses may be underdiagnosed mainly due to a vague clinical picture that can vary from complete lack of symptoms to acute coronary syndrome or sudden cardiac death. Early recognition of coronary IgG4-RD is essential to monitor disease activity and prevent life-threatening complications. We report a comprehensive non-invasive imaging evaluation of a patient affected by coronary IgG4-RD, which was diagnosed as an incidental finding during routine pre-laparoscopic cholecystectomy checkup. Non-invasive imaging revealed the presence of a peri-coronary soft-tissue mass that was stable at 12 months follow-up.

A rare case report on hypertrophic pachymeningitis: Serum IgG4-related disease

IgG4-related disease (IgG4-RD) is an immune-mediated inflammatory condition of unknown etiology characterized by invasion of tissue by IgG4-producing plasma cells. It can affect almost any organ system, but central nervous system involvement is a rare occurrence. A careful clinicopathological correlation is required to establish the diagnosis. The condition is highly treatable with glucocorticoids, but it is likely that it is underdiagnosed. Although IgG4-related disease responds quickly to glucocorticoids, if left untreated, can lead to end-stage organ failure and even death. We present a case of a 46-year-old female patient who presented with headache, tingling, numbness, flickering movement in her left lower limb gradually extending to torso and head, and loss of consciousness. After radiological and immunohistochemical studies, the diagnosis of IgG4-related hypertrophic pachymeningtis was confirmed. Corticosteroid therapy was administered, and the patient symptomatically improved. Clinicians should be aware of this rare condition, and the importance of early diagnosis and appropriate corticosteroid therapy should be emphasized.

Clinical characteristics of rheumatic disease-associated hypophysitis: A case series and review of literature

Rheumatic diseases have been reported to sometimes involve the pituitary gland. This study aims to characterize the clinical features and outcomes of patients with rheumatic disease-associated hypophysitis. We used the electronic medical record system in our hospital to identify nine patients with pituitary involvement in rheumatoid disease. We summarized the clinical characteristics, radiographic findings, treatments, and clinical outcomes of the 9 patients. We also performed a systematic literature review of systemic lupus erythematosus (SLE) cases with pituitary involvement published in PubMed and Wanfang databases from 1995 to 2021, and eight patients with complete information were selected. In the nine-patient cohort, the median age was 54 years, and the spectrum of rheumatic diseases included immunoglobulin G4-related disease (IgG4RD) (4/9), SLE (2/9), vasculitis (2/9), and Sjögren syndrome (SS) (1/9). All patients had pituitary abnormalities on radiological assessment, 6 developed diabetes insipidus (DI), and 8 presented with anterior pituitary hormone deficiencies in the disease duration. All the patients had multisystem involvement. As compared to hypophysitis with IgG4RD (IgG4-H), the age at onset of hypophysitis with SLE (SLE-H) patients was younger [(30.4 ± 16.4) years vs. (56.0 ± 0.8) years] and the disease duration was shorter [(14.0 ± 17.5) months vs. (71.0 ± 60.9) months] (P < .05). All patients were managed with glucocorticoids (GC) in combination with another immunosuppressant, and the majority of patients improved within 4 months. Six patients achieved disease remission while four required at least one hormone replacement therapy. Hypophysitis is a rare complication secondary to a variety of various rheumatic diseases that can occur at any stage. GC combined with additional immunosuppressants could improve patients' symptoms; however some patients also required long-term hormone replacement therapy in pituitary disorders.

Tolosa-Hunt Syndrome and IgG4 Diseases in Neuro-Ophthalmology

Tolosa-Hunt syndrome (THS) remains a challenging diagnosis for many neurologists. Often believed to be a rare presentation, the classical presentation is known to involve cranial nerves and tissues surrounding the cavernous sinus. Traditionally, a diagnosis of THS is considered when all secondary conditions have been ruled out. Yet, newer findings have elaborated a complex pathogenetic process with some overlap from the IgG4 spectrum of disorders, with which it shares many phenotypic similarities. In this narrative review, we present an updated picture of the condition focusing on the latest developments in the pathogenesis, diagnosis, and clinical management of these two conditions and use illustrative examples to highlight the salient features of this rare presentation.

Report of Two Cases of Pediatric IgG4-Related Lymphadenopathy (IgG4-LAD): IgG4-Related Disease (IgG4-RD) or a Distinct Clinical Pathological Entity?

IgG4-related disease (IgG4-RD) is a recently discovered immune-mediated fibroinflammatory condition, uncommon in the pediatric population, that could involve multiple organs and induce cancer-like lesions and organ damage. Its main features are multiple injuries in different sites, a dense lymphoplasmacytic infiltrate rich in IgG4 plasma cells, storiform fibrosis, and often high serological concentrations of IgG4. Autoimmune pancreatitis is the most common manifestation, mainly in adults. Two cases of IgG4-RD in children with lymph node localization of disease are reported. Localized or systemic lymph node involvement is common, but lymph node enlargement as the first and only manifestation of IgG4-RD is unusual, and therefore, hard to differentiate from other diseases. IgG4-related lymphadenopathy (IgG4-LAD) is most likely a distinct disease, described as isolated lymphadenopathy, related to the presence of elevated numbers of IgG4-positive plasma cells. Both disorders are likely to be misdiagnosed in children because they are characterized by rare and polymorphic features. IgG4-RD and IgG4-LAD should be considered in the differential diagnosis of disorders characterized by lymphadenopathy of uncertain etiology.

The unique diagnostic and management challenge of a patient with concomitant anti-interferon-gamma autoantibody associated immunodeficiency syndrome, IgG4-related disease, and treatment refractory, disseminated mycobacterium avium complex infection

BACKGROUND

Anti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge.

CASE PRESENTATION

A 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive.

CONCLUSIONS

This case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

TSLP promoting B cell proliferation and polarizing follicular helper T cell as a therapeutic target in IgG4-related disease

OBJECTIVE

To figure out the functions of thymic stromal lymphopoietin (TSLP) in IgG4-related disease (IgG4-RD).

METHODS

Plasma TSLP levels were tested by Elisa, and its receptors were detected by flow cytometry. Expressions of TSLP and TSLPR in involved tissues were stained by immunohistochemistry and immunofluorescence. Proliferation, apoptosis, and B subsets of TSLP stimulated-B cells were analyzed by flow cytometry. TSLP-stimulated B cells were co-cultured with CD4+ Naïve T cells. Signaling pathway was identified by RNA-sequencing and western blot. Anti-TSLP therapy was adapted in LatY136F knock-in mice (Lat, IgG4-RD mouse model).

RESULTS

Plasma TSLP level was increased in IgG4-RD patients and was positively correlated with serum IgG4 level and responder index (RI). TSLPR was co-localized with CD19+ B cells in the submandibular glands (SMGs) of IgG4-RD. TSLP promoted B cell proliferation, and TSLP-activated B cells polarized CD4+ naive T cells into follicular helper T (Tfh) cells through OX40L. RNA-sequencing identified JAK-STAT signaling pathway in TSLP-activated B cells and it was verified by western blot. Anti-TSLP therapy alleviated the inflammation of lung in Lat mice.

CONCLUSION

Elevated TSLP in IgG4-RD promoted B cells proliferation and polarized Tfh cells and might be served as a potential therapeutic target.

Immunoglobulin G4-Related Lung Disease Mimicking Lung Cancer: Two Case Reports

Immunoglobulin G4 (IgG4)-related disease is a rare systemic fibroinflammatory condition characterized by elevated serum IgG4 levels and infiltration of IgG4-positive plasma cells in various organs. IgG4-related lung disease shows varied radiologic features on chest CT. Patients usually present with a solid nodule or mass mimicking lung cancer; therefore, distinguishing between IgG4-related disease and other conditions is often challenging. Additionally, co-existing radiologic findings of IgG4-related lung disease may mimic metastasis or lymphangitic carcinomatosis of the lung. We report two cases of histopathologically confirmed IgG4-related lung disease mimicking lung cancer. Chest CT revealed a solid nodule or mass with ancillary radiologic findings, which suggested lung cancer; therefore, IgG4-related lung disease was radiologically indistinguishable from lung cancer in both cases. Measurement of serum IgG4 levels and clinical evaluation to confirm involvement of various organs may be useful to establish the differential diagnosis. However, surgical biopsy evaluation is needed for confirmation.

IgG4-Related Sclerosing Disease of the Temporal Bone: A Systematic Review

OBJECTIVE

IgG4-related disease (IgG4-RD) involving the temporal bone is an uncommon and underrecognized pathology often mistaken for malignancy. This systematic review is the first that aims to thoroughly analyze IgG4-RD of the temporal bone.

DATABASES REVIEWED

Ovid MEDLINE, EMBASE, Cochrane Library, and Google Scholar.

METHODS

We used the following search keywords: "lgG4-RD," "skull," "skull base," "cranial," "temporal bone," "inner ear." We additionally manually searched the bibliographies of relevant articles. The JBI Critical Appraisal Checklist for Case Reports and Case Series was used to assess the risk of bias; because of the scarcity of the reports, data were available through limited case series and reports; thus, data synthesis was not possible.

RESULTS

We identified 17 studies with 22 cases with temporal bone involvement. The most common presenting symptoms were hearing loss, otalgia, and headache. The mastoid and petrous bone were the most affected anatomical areas. Both computed tomography and magnetic resonance imaging were used. Biopsies showed the characteristic lymphoplasmacytic infiltrate in all cases, with histopathology being the diagnostic modality that set the diagnosis. Most patients were treated with corticosteroids ± surgery or a combination of corticosteroids and immunosuppressants with 95.5% symptomatic response and disease control.

CONCLUSION

IgG4-RD of the temporal bone radiologically manifests as space-occupying, lytic lesions; clinically, it presents with vague otological symptoms. Diagnosis involves a thorough workup, with histopathology being crucial in setting a definite diagnosis. IgG4-RD tends to respond well to systemic corticosteroids, whereas surgery is mostly required for diagnostic purposes.

Inflammatory Diseases of the Aorta: JACC Focus Seminar, Part 2

Inflammatory aortitis is most often caused by large vessel vasculitis (LVV), including giant cell arteritis, Takayasu's arteritis, immunoglobulin G4-related aortitis, and isolated aortitis. There are distinct differences in the clinical presentation, imaging findings, and natural history of LVV that are important for the cardiovascular provider to know. If possible, histopathologic specimens should be obtained to aide in accurate diagnosis and management of LVV. In most cases, corticosteroids are utilized in the acute phase, with the addition of steroid-sparing agents to achieve disease remission while sparing corticosteroid toxic effects. Endovascular and surgical procedures have been described with success but should be delayed until disease control is achieved whenever possible. Long-term management should include regular follow-up with rheumatology and surveillance imaging for sequelae of LVV.

From Suspicion to Diagnosis: Analysis on the Clinical Characteristics of 37 Cases of IgG4-Related Disease (IgG4-RD) in Northeast China

INTRODUCTION

IgG4-related disease (IgG4-RD) mimics a variety of disorders, the final diagnosis is heavily dependent on the doctor's familiarity with the disease, most patients are expected to get a good prognosis by early diagnosis and timely treatment.

METHODS

Retrospective analysis was carried out on 147 patients tested for serum IgG4 because of suspected IgG4-RD. These cases were grouped as the IgG4-RD group and non-IgG4-RD group according to the diagnostic criteria proposed by the Japanese IgG4-RD research group and the American College of Rheumatology and the European Union of Rheumatology. Characteristics of these patients were investigated and analyzed.

RESULTS

The onset age of IgG4-RD was 57.29 ± 14.03 years old, male to female ratio of IgG4-RD was 1.31:1. The most commonly affected organs were the pancreas (48.6%), lymph nodes (40.5%) and biliary tract (35.1%), the proportion of patients with simultaneous involvement of multiple organs is as high as 83.2%. A history of allergy is more common in IgG4-RD patients (32.4% vs 14.5%), the optimal critical value of serum IgG4/IgG ratio for diagnosis of IgG4-RD was 0.09 (sensitivity 94.7%, specificity 91.7%) and the optimal threshold for IgG diagnosis of IgG4-RD was 15.25g/L (sensitivity 73.7%, specificity 77.8%) in this study.

CONCLUSION

IgG4-RD is often manifested as multiple organ involvement, and is most likely to involve the pancreas, biliary tract and lymph nodes. Most patients were diagnosed in other departments instead of rheumatology. Serum IgG4 level, especially IgG4/IgG ratio has a higher predictive value for IgG4-RD. Early diagnosis is the key point to improve the prognosis.

Clinical characteristics and therapeutic response of immunoglobulin G4-related disease: a retrospective study of 127 Chinese patients

Background and aims

Immunoglobulin G4-related disease (IgG4-RD) is a multisystem fibroinflammatory condition. The aim of the present study was to characterize the clinical features and therapeutic response of patients with IgG4-RD and identify risk factors for disease relapse.

Methods

We collected baseline data of eligible patients with IgG4-RD and analyzed clinical features by interview and review of medical records. The patients who received glucocorticoids (GC) therapy with at least 3 months follow-up were used to characterize the therapeutic response and identify risk factors for relapse.

Result

Totally 127 IgG4-RD patients, including 92 males and 35 females, were enrolled in the present study. The median age of onset was 63.0 years, ranging from 23 to 86. The pancreas, bile duct and lymph nodes were the most frequently involved organs. The serum IgG4 level was elevated in 94.5% of the patients and was correlated with the number of organs involved. Patients classified as head and neck limited group were more likely to be female. Compared to Mikulicz syndrome and systemic involvement group, pancreato-hepatobiliary group had higher aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, bilirubin and lower IgG4 level. Mikulicz syndrome and systemic involvement group had the highest IgG4-RD RI score, IgG level. Among 92 patients who received medical therapy with at least 3 months follow-up, 76 received GC alone or in combination with immunomodulator (IM) and 16 patients did not take GC. 74 out of the 76 patients (97.3%) achieved remission, with 59 of them remained in remission and 15 of them relapsed. Whereas 16 patients did not take GC, among them, 6 patients achieved remission with one relapsed. On multivariate analysis, higher initial score of ACR/EULAR IgG4-RD Classification Criteria and GC withdrawal were independent predictors for relapse.

Conclusion

Four phenotypes of IgG4-RD showed different demographic and serological features. GC + IM therapy was safe and effective and might protect patients from relapse. The independent risk factors of relapse were GC withdrawal and higher score of ACR/EULAR IgG4-RD Classification Criteria.

Tissue IgG2/IgG4 Ratio as an Additional Tool to Distinguish IgG4-Related Disease From Other Fibroinflammatory Disorders

Interpretation of biopsies taken on suspicion of immunoglobulin (Ig)G4-related disease (IgG4-RD) may be hampered by uninterpretable immunohistochemical stains for IgG because of strong background signals. This study aims to determine the significance of tissue IgG2 positive plasma cell counts in IgG4-RD in comparison with non-IgG4-related inflammatory disorders. Descriptive, retrospective case-control study of 16 patients with IgG4-related orbital disease (IgG4-ROD) and 24 with extraorbital IgG4-RD. Histopathology and serology of this group was compared with 16 patients with orbital non-IgG4-related disorders and 22 patients with extraorbital non-IgG4-related disorders. The mean tissue IgG2/IgG4 ratio was 0.16 in IgG4-ROD and 0.27 in extraorbital IgG4-RD and far below 1 in 98% of patients. This was significantly lower compared with the non-IgG4-related disorders that showed a mean tissue IgG2/IgG4 ratio of 1.98 in the orbital and 2.20 in the extraorbital group (range: 0.20 to 10, P <0.05). In 74% of tissue samples an IgG2/IgG4 ratio >1 was seen. The tissue IgG2/IgG ratio was significantly lower in IgG4-RD compared with non-IgG4-related inflammatory disorders. Serum IgG2 concentration was not abnormal in patients with IgG4-RD. A significantly lower tissue IgG2/IgG4 and IgG2/IgG ratio was observed in IgG4-RD, compared with non-IgG4-related inflammatory disorders. Additional immunohistochemical staining for IgG2 positive plasma cells can be helpful in the diagnosis of IgG4-RD. Especially in cases with uninterpretable IgG staining, a well-recognized problem that may give rise to a failed interpretation of the biopsy.

Management of retroperitoneal fibrosis with endovascular aneurysm repair in patients refractory to medical management

Background

Early diagnosis and treatment of under-recognized retroperitoneal fibrosis (RPF) are essential before reaching the poorly responsive fibrotic stage. Although most patients respond to medical therapy, relapses and unresponsiveness are common. However, open surgery in medically resistant patients is associated with major adverse clinical events.

Methods

This is a single-centre longitudinal study of optimal medical therapy (OMT) vs. endovascular aneurysm repair (EVAR) in patients presenting with RPF to our tertiary referral vascular centre. Out of 22,349 aortic referrals, we performed 1,555 aortic interventions over twenty years. Amongst them, 1,006 were EVAR, TEVAR and BEVAR. Seventeen patients (1.09%) had documented peri-aortic RPF.

Results

Out of the 17 RPF patients, 11 received OMT only, while 6 underwent EVAR after the failure of OMT. 82% (n = 14) were male, and the median follow-up was 62.7 months (IQR: 28.2–106). Nine (52%) had immunoglobulin G4-related disease (4 OMT vs. 5 EVAR). EVAR patients had 100% technical success without perioperative mortality. Furthermore, all the EVAR patients were symptom-free following the intervention. Pre-operative aortic RPF index (maximum peri-aortic soft tissue diameter/maximum aortic diameter) was higher in the EVAR than in OMT. However, there was a significant decrement in the aortic RPF index following EVAR (P = 0.04).

Conclusion

We believe that when optimal medical therapy fails in RPF, EVAR provides a promising outcome. Further studies are recommended to establish the role of endovascular repair.

[Immunoglobulin-G4-related disease]

After years of confusion about apparently distinct clinical disease symptoms, the term IgG4-related disease (IgG4-RD) has been coined in 2001, uniting these fibroinflammatory clinical entities with a tendency for tumorous enlargement and tissue fibrosis. Over the past two decades, experimental and clinical studies could make astounding progress in the understanding of this elusive disease. By now, we have a reasonable idea of the pathophysiological mechanisms, which opens up new avenues for therapeutic approaches. It seems like a dense lymphoplasmacytic cell infiltrate, consisting of B‑cells, IgG4⁺ plasma cells, follicular T‑helper cells, CD4⁺ cytotoxic T‑cells and M2 macrophages induces a smoldering inflammatory reaction with a fibrogenic cytokine milieu. This stimulates fibroblasts to secrete extracellular matrix components, leading to the histopathologically characteristic storiform fibrosis and obliterative phlebitis. Macroscopically, this reaction results in diffuse organ swelling and tumorous lesions. The macroscopic and histological differentiation from conditions mimicking IgG4-RD can be challenging. This is especially true for granulomatous diseases, such as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The situation is further complicated by the fact that ANCAs can be positive in IgG4-RD and, vice versa IgG4 antibodies can be elevated in numerous differential diagnoses, such as infections, AAV, sarcoidosis, and malignancies. This article provides an overview of the multifaceted clinical condition of IgG4-RD with respect to the pathophysiology, diagnostic steps and treatment. Furthermore, an overview of the differential diagnoses is discussed especially with respect to granulomatous diseases.

Case Report: Diagnosis of Petrous Apex IgG4-Related Disease by Middle Cranial Fossa Craniotomy and Temporal Bone Biopsy

Introduction

Primary IgG4-related disease (IgG4-RD) of the temporal bone is a rare condition. Unlike typical petrous apicitis or Gradenigo syndrome, our patient presented exclusively with unilateral cranial nerve VI palsy and symptoms of diplopia. Skull base imaging demonstrated a destructive bony lesion in the petrous apex. Imaging and systemic investigations were insufficient to support a diagnosis. The diagnosis was achieved histologically after acquiring the specimen by middle cranial fossa craniotomy and temporal bone biopsy. This case report is thought to be the first published description of a diagnosis of IgG4-RD proven with the middle cranial fossa approach.

Case Report

We describe a 29-year-old female with primary IgG4-RD of the petrous apex of the temporal bone. This patient presented with a few-month history of left-sided headache and recent-onset diplopia due to paralysis of cranial nerve VI. Imaging demonstrated a petrous apex lesion, and comprehensive systemic investigations could not reach a diagnosis. A middle cranial fossa craniotomy and a biopsy of the temporal bone lesion were undertaken to establish the diagnosis. Histological confirmation of IgG4-RD was proven. Following treatment with corticosteroids, the patient experienced complete recovery and resolution of her symptoms.

Conclusion

This study describes a case of primary IgG4-RD of the petrous apex of the temporal bone that presented with diplopia and was diagnosed by middle fossa craniotomy and temporal bone biopsy. To the best of our knowledge, this is the first case description where primary diagnosis was made based on middle cranial fossa craniotomy and temporal bone biopsy.

An Unusual Presentation of Immunoglobulin G4-Related Disease (IgG4-RD) Causing Subglottic Stenosis

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that is known to involve multiple organs and was first described as an entity in 2003. It is characterized by lesions with a dense lymphoplasmacytic infiltrate, IgG4-positive plasma cells, storiform fibrosis, and frequently elevated serum IgG4 levels. Organs that are commonly involved include the pancreas, biliary tree, salivary glands, periorbital tissues, kidneys, retroperitoneum, lungs, pleura, thyroid, aorta, and lymph nodes. Rarer manifestations of IgG4-RD include central nervous system (CNS) involvement, prostatitis, mastitis, midline destructive disease, and nasopharyngeal disease. In this report, we discuss an atypical case of a young woman with laryngeal subglottic involvement leading to stenosis and airway obstruction, which was ultimately successfully managed with systemic immunosuppression. 

IgG4-related hypertensive granulomatous anterior uveitis

Purpose

To report a case of hypertensive granulomatous anterior uveitis in the setting of IgG4-related disease (IgG4-RD).

Observations

A 69-year-old man presented with no light perception vision in both eyes and bilateral granulomatous anterior uveitis with iris neovascularization and hyphema in the right eye. He also demonstrated concurrent polyuria, polydipsia, and altered mental status, and was diagnosed with new-onset diabetes mellitus. MRI revealed no orbital abnormalities, but showed bilateral occipital strokes attributed to hyperglycemic hyperosmolar syndrome. Chest CT revealed pleural-based nodules and mediastinal and abdominal lymphadenopathy, and a liver biopsy confirmed fibroinflammatory nodules with increased IgG4 positive plasma cell infiltrates, diagnostic of IgG4-RD. Serum IgG4 levels were 1381 mg/dL. The patient was treated with a combination of systemic and topical steroids, and later initiated on rituximab.

Conclusion and importance

IgG4-related ophthalmic disease may present as an isolated hypertensive granulomatous anterior uveitis without associated scleral or orbital involvement.

Inflammatory pseudotumor and myofibroblastic inflammatory tumor. Diagnostic criteria and prognostic differences

INTRODUCTION

Inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT) are two very rare entities that were formerly included in the same category; however, today they are considered two different diseases due to the neoplastic origin of the IMT. Our objective is to share our experience in the management of these two types of tumors that we must take into account in the differential diagnosis of pulmonary masses or nodules.

METHODS

Thirteen patients with a pathological diagnosis of IPT and IMT who underwent surgery between 2008 and 2019 were retrospectively studied. We recorded the pre and postoperative information of each one, as well as the survival analysis.

RESULTS

Of the 13 patients, 8 were men and 5 women. The mean age of presentation was 53,5 years. An atypical segmentectomy was performed in 6 patients; a lobectomy was necessary in 6 and a pneumonectomy in 1 case. In all cases a complete resection was achieved. Diagnosis was possible thanks to histology, immunohistochemical (IHQ) and fluorescent in situ hybridization (FISH) techniques determining the expression of IgG4 and the rearrangement of ALK, respectively. After a median follow up of 49 months, we didn't find any loco-regional or distant recurrence in the patients studied.

CONCLUSION

IPT and IMT are rare tumors with a very good prognostic. The diagnosis of both entities is based mainly on specific anatomopathological techniques. Surgery has, in most cases, both a diagnostic and therapeutic role.

Immunoglobulin G4-related disease presenting as an intracranial mass extended from the infratemporal fossa

Background

Neurological manifestations in immunoglobulin G4-related diseases (IgG4-RD) are rare and documented in <2% of cases. It commonly involves pachymeninges forming hypertrophic pachymeningitis and rarely forms tumor-like masses.

Case Description

We present our experience with a biopsy-proven case of IgG4-RD presenting with an intracranial extradural tumor-like mass infiltrating the temporal lobe. The patient was treated with high doses of corticosteroids followed by slow tapering. The neurological manifestations gradually improved and resolved after 2 months with a cerebral MRI showing a significant reduction in the tumoral size.

Conclusion

When it comes to intracranial mass, IgG4-RD neuropathy is one of the rarest differential diagnoses for the central nervous system tumors. Early recognition of IgG4-RD and appropriate establishment of its long-term treatment may avoid unnecessary investigations and morbidity.

Occult myocardial infarction due to an unusual cause: a case report of periarteritis involving the left coronary artery

Background

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition that affects multiple organs and systems.

Case summary

A 51-year-old man with a history of occult left apex myocardial infarction diagnosed based on electrocardiographic and echocardiographic findings underwent coronary computed tomography (CT) angiography for the evaluation of coronary artery disease; the findings revealed a soft-tissue mass that surrounded the aortic root and the distal portion of the left coronary artery. The mass was considered an inflammatory lesion; high glucose uptake on positron emission tomography/CT supported this assumption. Coronary angiography revealed 80% stenosis of the distal portion of the left anterior descending artery, which corresponded with the infarction. Intravascular ultrasound revealed hypoechoic regions outside the lumina of the stenotic segment. Based on these findings, IgG4-related periaortitis/periarteritis was suspected; the patient was accordingly treated with oral prednisone and methotrexate. At the 3-month follow-up, the periaortic mass had slightly reduced in size.

Discussion

Identification and diagnosis of IgG4-related cardiovascular disease are challenging; cases with localized coronary artery involvement may be misdiagnosed as atherosclerotic coronary artery disease. Although imaging techniques, including intracoronary imaging, may aid in differential diagnosis, their sensitivity and specificity still warrant further studies. Practical criteria that facilitate diagnosis and a better understanding of the disease are required.

IgG4-Related Sclerosing Cholangitis with Cholecystitis Mimicking Cholangiocarcinoma: A Case Report

IgG4-related diseases are rare multisystem disorders involving salivary glands, retroperitoneum, pancreas, biliary tract, and liver. Isolated biliary strictures and gall bladder involvement are rare in such patients, and presentation with cholangitis and weight loss can misguide the diagnosis toward malignancy. Here, we report an interesting case of IgG4-related biliary stricture with gall bladder involvement, presented with cholangitis and weight loss. The initial symptoms and imaging were guided toward the malignant possibilities of cholangiocarcinoma and pancreatic carcinoma. However, endosonography, serology, and histopathology clinched the diagnosis of IgG4-related disease. The patient was managed without any biliary intervention and with antibiotics, steroids, and steroid-sparing agents. There was a relapse of disease during the steroids taper that improved after hiking its doses. The disease responded with medical management on follow-up. We demonstrated the effectiveness of steroid-sparing agents to treat IgG4-related diseases, especially to avert the steroid-related adverse effects. This case highlights the possible mislead for the diagnosis and delayed management of IgG4 disease due to shared clinical features with hepatobiliary malignancies and the effectiveness of noninvasive measures of management.

Oral and maxillofacial manifestations of IgG4-related disease: A clinicopathological study

BACKGROUND

IgG4-related disease is a fibroinflammatory and immune-mediated condition, which has extremely variable clinical manifestations. In this study, we aim to investigate the clinicopathological features of IgG4-related disease involving the oral and maxillofacial region.

METHODS

Cases of IgG4-related disease manifesting in the oral and maxillofacial region were retrieved from three Brazilian institutions. Clinical and serological data were obtained from the patients' medical charts, while microscopic and immunohistochemical findings were revised by oral pathologists. Diagnosis followed the American College of Rheumatology/European League against Rheumatism criteria.

RESULTS

Seven patients diagnosed with IgG4-related disease were included in this study. Women were affected in all analysed cases, with a mean age of 55.4 years. Two patients presented with the clinical involvement of more than one oral and maxillofacial anatomic site. Therefore, our sample comprised nine oral and maxillofacial anatomic sites affected by IgG4-related disease. The submandibular gland was affected in four cases, the tongue and the parotid gland in two cases each, and the palate in one case. In a few cases, exploratory lower lip biopsy was used as a diagnostic approach. A moderate-to-severe lymphoid infiltrate containing plasma cells and lymphocytes, with an increased IgG4/IgG ratio, was common. Treatment varied and steroids were the most frequently used (57.4%). Six patients remained alive, while one died from unknown causes.

CONCLUSION

Although major salivary glands are commonly affected by IgG4-related disease, the oral cavity can also be involved, and lower lip biopsy may be an auxiliary diagnostic tool.

Steroid therapy still plays a crucial role and could serve as a bridge to the next promising treatments in patients with IgG4-related sclerosing cholangitis: Results of a Japanese Nationwide Study

OBJECTIVE

The acceptable duration of steroid therapy for patients with IgG4-sclerosing cholangitis (SC) has been under debate. Our aim is to clarify the feasible duration of steroid treatment.

DESIGN

We retrospectively reviewed the data of patients with IgG4-SC and analyzed the following: biliary status during the steroid therapy, incidence of remission, relapse, relapse-free survival rate, and steroid-related complications (SRCs).

RESULTS

Remission was achieved 99.5% (763/767) of patients who received steroid therapy, while remission rate dropped to 63.6% (78/129) of patients who didn't receive it. Relapse was noted in 19.7% (151/763) of the patients who received steroid. Besides, relapse rate went up 38.4% (30/78) of the counterpart. Normalization of the serum total bilirubin and serum alkaline phosphatase (ALP) levels were achieved at two weeks regardless of biliary drainage. Multivariate analysis identified younger onset, MST less than three years, immunosuppressant, and steroid cessation as independent risk factors for relapse. Steroid-free was achieved in the patients underwent MST only 3.4% over 54 months. SRCs were recorded in a total of 99 patients (12.9%) despite sufficient preemptive medications. Multivariate analysis identified history of malignancy and immunosuppressant as independent risk factors for SRCs.

CONCLUSION

Steroid therapy should be continued for no less than three years to reduce the risk of relapse, with use of preemptive measures taken around five years. The biliary drainage might not be mandatory. Steroid as 1st line therapy could serve as a bridge to further promising treatments.

IgG4-related Disease with a Cardiac Mass Causing Cerebral Infarction

Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by infiltration of extensive IgG4-positive plasma cells and lymphocytes. Although IgG4-RD has been observed in almost all organs, it rarely affects the myocardium. Cardiovascular lesions of IgG4-RD appear as aortic (aortic aneurysm and aortitis) and pericardial (constrictive pericarditis) lesions as well as pseudotumors around the coronary arteries. We herein report a case of IgG4-RD with a cardiac mass in the right atrium involving a sinus node. This condition caused arrhythmia and repeated strokes. We successfully treated the patient through resection of the cardiac mass, catheter ablation and immunosuppressive therapy.

[IgG4-related disease with nasopharyngeal malignancy-like manifestations]

Objective:The purpose of this article was to discuss the clinical features and imaging characteristics of IgG4-related disease（IgG4-RD） in order to identify nasopharyngeal IgG4-RD at an early stage. Methods:The basic information of the patients, including age, sex, symptoms, disease duration and treatment process, was collected through the electronic case system. Laboratory tests including nasal endoscopy, EBV levels, IgG4 levels and C-reactive protein levels were recorded during hospitalization and outpatient follow-up. All radiological imaging and postoperative pathology data are collected, analyzed and summarized. Results:All patients underwent partial excisional biopsy of the lesion. The pathological findings showed inflammatory granulomatous and fibrous tissue hyperplasia with a high infiltration of lymphocytes, plasma cells and neutrophils, and immunohistochemistry examination showed IgG4+ plasma cells were more than 10 per high magnification field. Combining medical history, imaging, serological findings and relevant treatment, all four patients were diagnosed with IgG4-associated disease. And their symptoms improved significantly after hormonal and immunosuppressive treatment. Conclusion: IgG4-RD has a highly similar clinical presentation with nasopharyngeal carcinoma. Differentiation from IgG4-RD should be considered for those pathology cannot be clarified by multiple biopsies. Timely diagnosis of IgG4-RD is important to prevent secondary organ damage in patients with active disease.

Derivation and Validation of Algorithms to Identify Patients With Immunoglobulin-G4-Related Disease Using Administrative Claims Data

OBJECTIVE

Immunoglobulin-G4-related disease (IgG4-RD) is a systemic autoimmune disease that can affect nearly any organ, but its epidemiology remains poorly understood. Validated algorithms to identify cases in claims data will enable studies to describe IgG4-RD epidemiology in the general population.

METHODS

Potential claims-based algorithms were developed by IgG4-RD experts using a combination of International Classification of Diseases, Ninth Revision (ICD-9) and International Classification of Diseases, 10th Revision (ICD-10) codes, dispensed medications, and procedure codes for immunoglobulin G (IgG) subclass testing. Algorithms were tested using Medicare Parts A, B, and D linked to medical records (2007-2017). Classification of cases as IgG4-RD was determined using the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) classification criteria for IgG4-RD. We estimated the positive predictive value (PPV) of each algorithm; sensitivity was determined using a cohort of patients with IgG4-RD also enrolled in Medicare Parts A, B, and D during the study period.

RESULTS

We identified seven algorithms that used a combination of ICD-9 and ICD-10 codes, medication prescriptions, and/or IgG subclass tests to identify patients with IgG4-RD. The PPV of algorithms in the derivation cohort ranged from 57% to 100%, and sensitivity ranged from 0% to 58%. The best performing algorithm in the validation cohort had a PPV of 81% and a sensitivity of 58%. Typical IgG4-RD manifestations were observed in the cohort (n = 36) assembled by this algorithm, including 50% with sialadenitis, 64% with pancreatic disease, 31% with renal disease, and 59% with an elevated IgG4 concentration.

CONCLUSION

We derived and validated a well-performing algorithm to identify IgG4-RD cases with typical manifestations of the disease. The claims-based algorithm can be used in research studies of IgG4-RD.

Vision loss caused by immunoglobulin G4-related disease of the skull base complicated by a mucocele of the sphenoid sinus

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory disorder and manifestation in de paranasal and sphenoid sinus is well recognized. In this patient, IgG4-RD presented in an unusual manner with vision loss due to mucocele formation in the sphenoid sinus.

CASE DESCRIPTION

A 19-year-old man, with an unremarkable medical history, was referred with decreased vision in the left eye, headaches, and a sharp pain in the left orbit and ear. Compression of the left optic nerve due to a large mucocele caused papillary edema and emergency endoscopic marsupialization of the mucocele was performed. When the vision decreased again, a more extensive decompressing sphenoidotomy was performed. Histopathology showed IgG4-RD. Despite dexamethasone, the lesion expanded to the anterior skull base and the patient required repeat endoscopic surgery. After 3 months, a decrease in smell and vision warranted for a fourth extensive endoscopic decompressing surgery, complicated by a cerebrospinal fluid leak. Prednisone and later rituximab were commenced. Unfortunately, the patient reported a complete loss of vision after 4 months of rituximab due to increased mass effect on the optic nerve. An extensive combined craniofacial-endoscopic surgery was performed to remove the entire mucocele and to prevent further contralateral and intracranial progression. Methylprednisolone monthly was commenced to prevent further complications.

DISCUSSION

This case illustrates that in therapy-resistant sino-orbital IgG4-RD, extensive surgery might be necessary at an earlier stage. It may even be the only option to prevent irreversible damage to the surrounding tissues. A multidisciplinary approach in the management of sino-orbital IgG4-RD is therefore warranted.

IgG4-related prostatitis manifesting as urinary obstruction in a 28-year-old male

Background

Immunoglobulin G4-related disease (IgG4-RD) is a systemic lymphoproliferative disorder characterized by elevated serum IgG4 levels and tumefactive lesions that can involve nearly every organ system. Involvement of the prostate is rare but has been reported in limited cases.

Case presentation

A 28-year-old man of Asian descent with a history of sinusitis and priapism presented to hospital with rigors and voiding symptoms. He was diagnosed with IgG4-RD one month prior to presentation, following pathological analysis of a submandibular mass that demonstrated chronic sclerosing sialadenitis. On presentation, white blood cell count, C-reactive protein, and prostate serum antigen levels were all within normal limits. Examination was notable for a large, firm prostate, and a foley catheter was inserted. Contrast CT of the abdomen was unremarkable. Further workup revealed elevated serum IgG4 levels (9.22 g/L) and he was subsequently started on prednisone 35 mg daily. Imaging to screen for systemic IgG4-RD involvement demonstrated paravertebral soft tissue involvement and he was given rituximab 1000 mg IV × 2 doses. MRI revealed diffuse prostatitis. Five days after starting prednisone and one day after his first dose of rituximab, he successfully passed trial of void and was discharged home.

Conclusions

IgG4-related prostatitis is a rare and underrecognized manifestation of IgG4-RD. Our case highlights the need to consider IgG4-related prostatitis as an etiology of urinary obstruction in young individuals. Resolution of symptoms following treatment with steroids may be diagnostic of IgG4-related prostatitis, and may potentially avoid the need for invasive diagnostic procedures such as prostate biopsy.

Isolated IgG4-related cholecystitis with localized gallbladder wall thickening mimicking gallbladder cancer: a case report and literature review

BACKGROUND

IgG4-related cholecystitis, which is a manifestation of IgG4-related disease in the gallbladder, is associated with autoimmune pancreatitis or IgG4-related sclerosing cholangitis in most cases; isolated gallbladder lesions without systemic manifestations are very rare. Gallbladder wall thickening is often diffuse, but sometimes localized, in which case, differentiation from gallbladder cancer becomes difficult. The characteristic features of IgG4-related cholecystitis on imaging that would enable differentiation from gallbladder cancer remain poorly described.

CASE PRESENTATION

We present a rare case of isolated IgG4-related cholecystitis with localized gallbladder wall thickening that was clinically difficult to distinguish from malignancy before resection. An 82-year-old man was referred to our hospital because of gallbladder wall thickening on abdominal ultrasonography without any symptoms. Dynamic computed tomography of the abdomen showed localized wall thickening from the body to the fundus of the gallbladder that was enhanced from an early stage with a prolonged contrast effect. There were no other findings, such as pancreatic enlargement and bile duct dilatation. Magnetic resonance cholangiopancreatography revealed neither dilatation nor stenosis of the bile duct and pancreatic duct. Endoscopic ultrasonography (EUS) showed a smooth layered thickening of the gallbladder wall with a maximum thickness of 6 mm and a well-preserved outermost hyperechoic layer in the same area. Laparoscopic cholecystectomy was performed because malignancy could not be completely ruled out. Pathological examination of a resected specimen revealed IgG4-positive plasma cell infiltration, fibrosis, and phlebitis. Although the serum IgG4 level measured after resection was normal, the condition was ultimately diagnosed as probable IgG4-related cholecystitis according to the 2020 revised comprehensive diagnostic criteria for IgG4-related disease. The EUS images reflected the pathological findings, in which lymphocytic infiltration was distributed in a laminar fashion in the gallbladder wall.

CONCLUSIONS

Although rare, isolated IgG4-related cholecystitis with localized wall thickening mimicking gallbladder cancer remains a clinical problem. A smooth laminar thickening of the gallbladder wall on EUS imaging could be one of the most informative characteristics for differentiating IgG4-related cholecystitis from gallbladder cancer.

IgG4-related diseases of the digestive tract

IgG4-related conditions affecting the digestive tract are part of a multi-organ fibro-inflammatory disorder termed IgG4-related disease (IgG4-RD), with autoimmune pancreatitis and IgG4-related cholangitis being the most prominent manifestations. Gastrointestinal symptoms include jaundice, weight loss, abdominal pain, biliary strictures, and pancreatic and hepatic masses that mimic malignant diseases. IgG4-RD manifestations occur less frequently elsewhere in the digestive tract, namely in the oesophagus, retroperitoneum or intestine. Evidence-based European guidelines frame the current state-of-the-art in the diagnosis and management of IgG4-related digestive tract disease. Diagnosis is based on histology (if available), imaging, serology, other organ involvement and response to therapy (HISORt criteria). Few biomarkers beyond serum IgG4 concentrations are reliable. The first-line therapy (glucocorticoids) is swiftly effective but disease flares are common at low doses or after tapering. Second-line therapy might consist of other immunosuppressive drugs such as thiopurines or rituximab. Further trials, for example, of anti-CD19 drugs, are ongoing. Although an association between IgG4-RD and the development of malignancies has been postulated, the true nature of this relationship remains uncertain at this time.

LGI1 antibody encephalitis: acute treatment comparisons and outcome

OBJECTIVE

To compare acute treatment responses and long-term outcome in leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis.

METHODS

Retrospective case series of 118 patients with LGI1 antibody encephalitis evaluated at Mayo Clinic across all US sites from 1 May 2008 to 31 March 2019. Patient clinical data were identified and analysed through the neuroimmunology laboratory and electronic medical record. LGI1 antibody detection was by cell-based indirect immunofluorescence assay of serum, cerebrospinal fluid or both. Clinical outcomes were faciobrachial dystonic seizure (FBDS) resolution, modified Rankin Scale (mRS) score, Kokmen Short Test of Mental Status (STMS) score (0-38 point scale) and neuropsychometric testing results.

RESULTS

Compared with intravenous immunoglobulin (IVIg) (n=21), patients treated with single-agent acute corticosteroids (intravenous, oral or both) (n=49) were more likely to experience resolution of FBDS (61% vs 7%, p=0.002) and improvements in mRS score (ΔmRS score 2 vs 0, p=0.008) and median Kokmen STMS scores (ΔKokmen STMS score 5 points vs 0 points, p=0.01). In 54 patients with long-term follow-up (≥2 years), the median mRS score was 1 (range 0-6) and the median Kokmen STMS score was 36 (range 24-38) after all combinations of immunotherapy. Neuropsychometric testing in 32 patients with long-term follow-up (≥2 years) demonstrated short-term memory impairments in 37%.

CONCLUSIONS

Corticosteroids appeared more effective acutely than IVIg in improving LGI1 antibody encephalitis in this retrospective comparison of immunotherapies. While improvement with immunotherapy is typical and long-term outcome is favourable, short-term memory deficits are noted in approximately a third of the patients.

The Role of Symptom Duration and Serologic Factors in the Relapse of IgG4-Related Ophthalmic Disease following Surgery: A Retrospective Cohort Study

IgG4-related disease (IgG4-RD) affects multiple organs and is characterized by immune-mediated inflammation and fibrosis; IgG-RD affecting orbital tissue is known as IgG4-related ophthalmic disease (IgG4-ROD). This research is aimed at exploring whether symptom duration and common serologic factors, such as IgG, IgE, and eosinophils, are potential risk factors for IgG4-ROD patient relapse after surgery and identifying possible causes of the positive correlation between symptom duration and relapse. This retrospective cohort study included 40 IgG4-ROD patients after surgery. Auxiliary inspection results were obtained before surgery and during follow-up, and relapse risk factors were identified based on previous studies. We used the Spearman rank correlation test to reveal the relationship between symptom duration and relapse time and identified the optimal cutoff value for symptom duration by X-tile. Then, we divided the patients into the long-duration and short-duration groups. Kaplan-Meier survival analyses and log-rank tests were performed to identify the relationship between symptom duration and relapse using X-tile software. Finally, we studied the relationship between previously studied relapse risk factors and symptom duration. The survival curves of the long-duration and short-duration groups were obviously different, and the baseline serum IgG, IgE, and eosinophil levels and asthma concomitant rate were significantly different between the long-duration and short-duration groups. Furthermore, the baseline serum IgG (r = 0.485, P = 0.002), IgE (r = 0.350, P = 0.037), and eosinophil (r = 0.6535, P < 0.0001) levels were positively correlated with symptom duration. Our study shows that IgG4-ROD symptom duration is significantly positively correlated with relapse rate and negatively correlated with relapse time. Symptom duration was positively correlated with serum baseline IgG4, IgE, and eosinophil levels and asthma history, which were potential risk factors for disease relapse. We recommended that IgG4-ROD patients with symptom durations greater than 96 months continue to receive maintenance steroid therapy longer than 1 year postsurgery to reduce the relapse rate.

Orchestration of Immune Cells Contributes to Fibrosis in IgG4-Related Disease

This review summarizes recent progress in understanding the pathogenesis of IgG4-related disease (IgG4-RD), with a focus on fibrosis. Several studies reported that CD4+ T cells with cytotoxic activity promoted by the secretion of granzyme and perforin, cytotoxic CD4+ T cells (CD4+CTLs), and disease-specific activated B cells, infiltrated inflamed tissues and cooperated to induce tissue fibrosis in autoimmune fibrotic diseases such as IgG4-RD, systemic sclerosis, and fibrosing mediastinitis. An accumulation of cells undergoing apoptotic cell death induced by CD4+CTLs and CD8+CTLs followed by macrophage-mediated clearing and finally tissue remodeling driven by cytokines released by CD4+CTLs, activated B cells, and M2 macrophages may contribute to the activation of fibroblasts and collagen production. In IgG4-RD, this process likely involves the apoptosis of non-immune, non-endothelial cells of mesenchymal origin and subsequent tissue remodeling. In summary, CD4+CTLs infiltrate affected tissues where they may cooperate with activated B cells, CD8+CTLs, and M2 macrophages, to induce apoptosis by secreting cytotoxic cytokines. These immune cells also drive fibrosis by secreting pro-fibrotic molecules in IgG4-RD.