Project description:IgG4-related disease (IgG4-RD) is a spectrum of complex fibroinflammatory disorder with protean manifestations mimicking malignant neoplasms, infectious or non-infectious inflammatory process. The histopathologic features of IgG4-RD include lymphoplasmacytic infiltration, storiform fibrosis and obliterative phlebitis together with increased in situ infiltration of IgG4 bearing-plasma cells which account for more than 40% of all IgG-producing B cells. IgG4-RD can also be diagnosed based on an elevated serum IgG4 level of more than 110 mg/dL (normal < 86.5 mg/mL in adult) in conjunction with protean clinical manifestations in various organs such as pancreato-hepatobiliary inflammation with/without salivary/lacrimal gland enlargement. In the present review, we briefly discuss the role of genetic predisposition, environmental factors and candidate autoantibodies in the pathogenesis of IgG4-RD. Then, we discuss in detail the immunological paradox of IgG4 antibody, the mechanism of modified Th2 response for IgG4 rather than IgE antibody production and the controversial issues in the allergic reactions of IgG4-RD. Finally, we extensively review the implications of different immune-related cells, cytokines/chemokines/growth factors and Toll-like as well as NOD-like receptors in the pathogenesis of tissue fibro-inflammatory reactions. Our proposals for the future investigations and prospective therapeutic strategies for IgG4-RD are shown in the last part.
Project description:A 51-year-old woman visited our clinic for orthopnea, chest discomfort, and facial and leg edema. Acute kidney injury and pleural effusion were diagnosed and she received hemodialysis. This is a rare case of IgG4-related disease diagnosed by renal biopsy in the patient with retroperitoneal fibrosis and severe acute kidney injury, which progressed rapidly and required hemodialysis without markedly elevated serum IgG4 level and urinary tract obstruction. Immunostaining of a kidney biopsy revealed IgG4-related renal disease and magnetic resonance imaging showed retroperitoneal fibrosis in the paraspinal and presacral areas. After 3 days of glucocorticoid treatment, renal function and bilateral pleural effusion were restored. Another 2 months of glucocorticoid treatment decreased the extent of retroperitoneal fibrosis on follow-up abdominal computed tomography. IgG4-related disease is a recently recognized fibro-inflammatory condition with a dense lymphoplasmacytic infiltration of IgG4-positive plasma cells. The kidney and retroperitoneum are the frequently associated organs in IgG4-related disease. This case shows that IgG4-related disease can involve the kidney and/or other organs and be diagnosed by kidney biopsy.
Project description:BACKGROUND:The aim of this study was to identify fibrosis-related serological surrogate outcome measures in patients with immunoglobulin G4-related disease (IgG4-RD). METHODS:This was a clinical observational study of 72 patients with untreated IgG4-RD from four institutions in Japan. The serum concentrations of growth differentiation factor 15 (GDF-15), CCL2, hyaluronic acid (HA), amino-terminal propeptide of type III procollagen (PIIINP), and tissue inhibitor of metalloproteinases 1 (TIMP-1) were measured by enzyme-linked immunosorbent assays. The enhanced liver fibrosis (ELF) score was calculated from the TIMP-1, PIIINP, and HA values. We evaluated associations between the values of these biomarkers and laboratory data, the IgG4-RD responder index (IgG4-RD RI) score, and organ involvements. RESULTS:Compared with the 44 healthy controls, the patients with IgG4-RD showed significantly elevated serum concentrations of GDF-15, MCP-1, HA, PIIINP, and TIMP-1 and ELF scores. The patients' serum concentrations of GDF-15, CCL2, HA, and TIMP-1 (but not PIIINP) were positively correlated with each other. Among them, serum GDF-15 most efficiently distinguished patients with IgG4-RD from healthy controls. Serum GDF-15 was not associated with the IgG4-RD RI score or the number of organ involvements but was independently associated with the presence of retroperitoneal fibrosis and with parotid gland involvement. CONCLUSIONS:We observed increased serological surrogate outcome measures of fibrosis in IgG4-RD. GDF-15 may precisely reflect the fibrotic degree in patients with IgG4-RD.
Project description:A 67-year-old man with a history of asbestos exposure and rounded atelectasis complained of cough and swelling in the left submandibular region. Computed tomography showed an increase in size of the right lower lung lobe lesion, which was recognized as the pre-existing rounded atelectasis, as well as swelling of the pancreas and submandibular glands. Biopsy from a submandibular gland and the pulmonary lesion led to a diagnosis of immunoglobulin G4-related disease (IgG4-RD). IgG4-RD is a recently recognized disease that was first reported as an autoimmune disease; however, some reports have indicated another pathogenesis of an allergic nature that is characterized by type 2 helper T cell (Th2) inflammation. Additionally, it is recognized that long-term exposure to asbestos can cause immune dysregulation. Here we present a case of IgG4-RD associated with asbestos-related pleural disease. Asbestos-induced immune dysregulation may be one etiology of IgG4-RD.
Project description:Retroperitoneal fibrosis (RPF) refers to a fibro-inflammatory lesion in the retroperitoneum, often anterolateral to the aorta. Most cases are due to IgG4-related disease (IgG4-RD) or are idiopathic. RPF can lead to severe morbidity. Treatment strategies remain poorly-defined. We evaluated the efficacy and safety of rituximab (RTX) for idiopathic or IgG4-related RPF.We retrospectively reviewed the records of patients who had RPF treated with RTX. Treatment response was determined by assessing changes in both clinical features, including symptoms and laboratory measurements, as well as in the radiographic dimensions of the lesion.Twenty-six patients with IgG4-related (n = 19) or idiopathic RPF (n = 7) were identified. Patients without histopathological evidence of IgG4-RD on either retroperitoneal biopsies or sampling of extra-retroperitoneal organs were considered to have idiopathic RPF. Of the 26 patients, 19 (73%) received RTX without additional glucocorticoids. All 19 patients who presented with pain reported symptomatic improvement following RTX. Among 25 patients with follow-up imaging, 22 (88%) had radiologic improvement. Among 10 patients with ureteral stents and/or percutaneous nephrostomy tubes, 4 (40%) underwent successful stent or tube removal. Responses to treatment were similar among those treated with RTX monotherapy and those treated with RTX and glucocorticoids. RTX was generally well tolerated, but 3 (12%) patients experienced severe infections.In this study, RTX for RPF led to resolution of symptoms in all patients and radiographic improvement in the majority. Prospective studies of RTX for RPF are indicated.
Project description:Retroperitoneal fibrosis (RPF) is an uncommon condition characterized by inflammation and fibrosis in the retroperitoneal space. More than two-thirds of RPF are idiopathic, with the remaining stemed from a variety of secondary causes. It was suggested that IgG4-related RPF is a secondary form of RPF. We undertook this study to compare detailed demographic, clinical and laboratory characteristics of IgG4-related RPF and IRPF in a large Chinese cohort. We retrospectively reviewed the medical records of 132 RPF patients diagnosed at Peking University People's Hospital between March 2010 and March 2018. Among the 132 patients, the mean age at disease onset was 54.8 years. IgG4-related RPF group showed greater male predominance compared to IRPF group. IgG4-related RPF patients showed a longer interval between symptom onset and diagnosis, and allergic diseases were more common in this group. Sixty-four patients (48.4%) had lower back pain, which was more common in IRPF group than that in IgG4-related RPF patients. In terms of organ involvement, although 42 of 47 patients (89.3%) with IgG4-related RPF had other organ involvement, there were no patients in the IRPF group with other organ involvement. In addition, the serum IgG4 level, elevated eosinophils counts and IgE level were significantly higher in IgG4-related RPF patients. We described the demographic, clinical and laboratory differences between IgG4-related RPF and IRPF patients, indicating their potential differences in pathogenesis, which was of great importance to diagnose and manage the two phenotypes.
Project description:Immunoglobulins are an essential part of the humoral immune response. IgG4 antibodies are the least prevalent subclass and have unique structural and functional properties. In this review, we discuss IgG4 class switch and B cell production. We review the importance of IgG4 antibodies in the context of allergic responses, helminth infections and malignancy. We discuss their anti-inflammatory and tolerogenic effects in allergen-specific immunotherapy, and ability to evade the immune system in parasitic infection and tumour cells. We then focus on the role of IgG4 autoantibodies and autoantigens in IgG4-autoimmune diseases and IgG4-related disease, highlighting important parallels and differences between them. In IgG4-autoimmune diseases, pathogenesis is based on a direct role of IgG4 antibodies binding to self-antigens and disturbing homeostasis. In IgG4-related disease, where affected organs are infiltrated with IgG4-expressing plasma cells, IgG4 antibodies may also directly target a number of self-antigens or be overexpressed as an epiphenomenon of the disease. These antigen-driven processes require critical T and B cell interaction. Lastly, we explore the current gaps in our knowledge and how these may be addressed.
Project description:Some forms of idiopathic retroperitoneal fibrosis (RF) have recently been considered to be a part of the spectrum of immunoglobulin G4 (IgG4)-related disease. This case report is the first description of a spontaneous remission in a patient with pathologically proven IgG4-related RF. Although the pathogenesis and long-term disease behavior of IgG4-related RF remains unknown, we believe that an initial assessment consisting of only careful monitoring might be one important strategy, especially in asymptomatic IgG4-related RF patients without nephropathy, while carefully monitoring these patients for the risk of recurrence.
Project description:BackgroundImmunoglobulin G4-related disease (IgG4-RD) and systemic sclerosis (SSc) are rare autoimmune diseases characterized by the presence of CD4+ cytotoxic T cells in the blood as well as inflammation and fibrosis in various organs, but they have no established etiologies. Similar to other autoimmune diseases, the gut microbiome might encode disease-triggering or disease-sustaining factors.MethodsThe gut microbiomes from IgG4-RD and SSc patients as well as healthy individuals with no recent antibiotic treatment were studied by metagenomic sequencing of stool DNA. De novo assembly-based taxonomic and functional characterization, followed by association and accessory gene set enrichment analysis, were applied to describe microbiome changes associated with both diseases.ResultsMicrobiomes of IgG4-RD and SSc patients distinctly separated from those of healthy controls: numerous opportunistic pathogenic Clostridium and typically oral Streptococcus species were significantly overabundant, while Alistipes, Bacteroides, and butyrate-producing species were depleted in the two diseases compared to healthy controls. Accessory gene content analysis in these species revealed an enrichment of Th17-activating Eggerthella lenta strains in IgG4-RD and SSc and a preferential colonization of a homocysteine-producing strain of Clostridium bolteae in SSc. Overabundance of the classical mevalonate pathway, hydroxyproline dehydratase, and fibronectin-binding protein in disease microbiomes reflects potential functional differences in host immune recognition and extracellular matrix utilization associated with fibrosis. Strikingly, the majority of species that were differentially abundant in IgG4-RD and SSc compared to controls showed the same directionality in both diseases. Compared with multiple sclerosis and rheumatoid arthritis, the gut microbiomes of IgG4-RD and SSc showed similar signatures; in contrast, the most differentially abundant taxa were not the facultative anaerobes consistently identified in inflammatory bowel diseases, suggesting the microbial signatures of IgG4-RD and SSc do not result from mucosal inflammation and decreased anaerobism.ConclusionsThese results provide an initial characterization of gut microbiome ecology in fibrosis-prone IgG4-RD and SSc and reveal microbial functions that offer insights into the pathophysiology of these rare diseases.
Project description:Purpose: To define the treatment response and long-term outcomes of a large IgG4-related ophthalmic disease (IgG4-ROD) cohort. Methods: A total of 132 patients with a minimum follow-up of 1 year were included in this study. Demographic, clinical, and laboratory data were collected. Treatment response was assessed by the IgG4-RD responder index (IgG4-RD RI). Risk factors for relapse were analyzed with the multivariate Cox regression analysis. Results: The median follow-up time was 39 months. Lacrimal gland involvement was detected in 87.9% of cases. Extraocular muscles, the trigeminal nerve, and other soft tissue were affected in 25.8, 6.1, and 18.2% of patients. The relapse rate of watchful waiting, glucocorticoid monotherapy, immunosuppressant monotherapy, and combination therapy was 50.0, 51.7, 50.0, and 26.7% (p = 0.038), respectively. The combination therapy group exhibited shorter glucocorticoids therapy duration (36 vs. 48 months, p = 0.009) and maintenance period (24 vs. 42 months, p = 0.003). At the 6th month, the median IgG4-RD RI declined from 12 to 1 and 105 (79.5%) patients achieved complete response (CR). Relapse occurred in 49 (37.1%) patients. The multivariate Cox regression analysis exhibited that CR at the 6th month was an independent protective factor for relapse. Patients with multiple ocular lesions suffered from a higher risk of relapse. No patient had severe adverse reactions to the treatment in this study. Conclusion: Relapse was common in patients with IgG4-ROD. Patients receiving combination therapy showed a lower relapse rate and a shorter glucocorticoids therapy period. The presence of multiple ocular lesions was associated with a higher risk of relapse. CR at the 6th month might be a predictor for a better prognosis in IgG4-ROD. Thus, a more aggressive regimen should be prescribed for patients with a poor initial response.