A woman in her 30s presented with a 12-month history of reduced mouth opening and swelling on the right side of her mandible. The swelling was non-tender and firm on palpation. The swelling began to increase in size after the extraction of her carious wisdom tooth. Histopathological and serological examinations confirmed the diagnosis of IgG4-related disease, manifested as a mass in the mandible. The patient was prescribed oral corticosteroids at a tapering dosage over 8 weeks. After 3 months, there was an improvement in the patient\'s mouth opening and a reduction in the size of the swelling. The patient remains in follow-up care. Including IgG4-related disease in the list of potential diagnoses for oral soft tissue masses is crucial, given their positive response to medical treatment, highlighting the significance of an accurate diagnosis to prevent unnecessary surgery, with oral lesions potentially serving as early indicators before multiorgan complications arise.

IgG4-related disease (IgG4-RD) is a recently described autoimmune disorder characterized by elevated serum IgG4 levels and tissue infiltration of IgG4+ plasma cells in multiple organ systems. Recent advancements have significantly enhanced our understanding of the pathological mechanism underlying this immune-mediated disease. T cell immunity plays a crucial role in the pathogenesis of IgG4-RD, and follicular helper T cells (Tfh) are particularly important in germinal center (GC) formation, plasmablast differentiation, and IgG4 class-switching. Apart from serum IgG4 concentrations, the expansion of circulating Tfh2 cells and plasmablasts may also serve as novel biomarkers for disease diagnosis and activity monitoring in IgG4-RD. Further exploration into the pathogenic roles of Tfh in IgG4-RD could potentially lead to identifying new therapeutic targets that offer more effective alternatives for treating this condition. In this review, we will focus on the current knowledge regarding the pathogenic roles Tfh cells play in IgG4-RD and outline potential therapeutic targets for future clinical intervention.

暂无摘要。

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by chronic activation of the immune system and a tendency to form tumorous lesions. IgG4-RD is frequently characterized by the presence of tumor-like masses affecting multiple organs and is easily mistaken for a malignant neoplasm. However, IgG4-RD affecting the appendix is extremely rare, with only seven cases reported previously. We report the case of a woman in her early 60s who presented with insidious abdominal pain and radiological findings mimicking appendiceal neoplasms. After diagnosing appendiceal neoplasms, surgery was performed. The patient had a serum IgG4 concentration of <1.35 g/L, which did not satisfy one of the three revised comprehensive diagnostic criteria for IgG4-RD. A pathological examination was conducted, and the patient was diagnosed with appendiceal IgG4-RD. To the best of our knowledge, there have been no previously reported cases of IgG4-RD affecting the appendix in patients with low serum IgG4 concentrations. This report may prove beneficial for the future understanding of IgG4-RD and for the revision of diagnostic and treatment strategies.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is a chronic, immune-mediated condition characterized by fibro-inflammatory lesions with lymphoplasmacytic infiltration. Diagnosis traditionally relies on histopathological findings, including the presence of IgG4+ plasma cells. However, due to challenges in biopsy accessibility, additional measures are needed to facilitate diagnosis.
OBJECTIVE: To identify additional parameters for characterizing IgG4-RD patients.
METHODS: We compared several circulating factors between a cohort of patients with IgG4-RD disease seen at our hospital between 2017 and 2023 and healthy controls.
RESULTS: Among 16 suspected patients, 13 were confirmed to have IgG4-RD, and 3 were classified as highly likely. Comparison with controls revealed differences in white blood cell count (WBC) (Folf change (FC) 1.46, P < 0.05), plasmablasts (FC 3.76, P< 0.05), plasmablasts CD38 (FC 1.43, P < 0.05), and CD27 (FC 0.66, P = 0.054), thus highlighting potential markers for IgG4-RD diagnosis. Treatments with steroids/rituximab tend to reduce plasmablast (FC 0.6) and IgG4 (FC 0.28) levels and to increase Gal-3 levels.
CONCLUSIONS: Levels of plasmablasts are a significant diagnostic feature in IgG4-RD. Healthy individuals have a lower level of plasmablasts. Elevated Gal-3 in serum of patients with IgG4-RD suggests a role in plasmablast activation. CD38/CD27 expression by plasmablasts emerges as a potential marker. Further research on a larger cohort is needed to confirm these findings.

BACKGROUND: IgG4-related diseases are very uncommon, and its diagnosis and treatment are complicated as it encompasses multiple disciplines.
METHODS: A 77-year-old woman was admitted with a jaw mass and nausea and vomiting. Laboratory tests showed elevated serum IgG4, pituitary MRI suggested thickening of the pituitary stalk, and head and neck CT suggested orbital and mandibular masses. Patients with mandibular mass were diagnosed with Mikulicz\'s disease with IgG4-related hypophysitis. We found no other evidence of causing thickening of the pituitary stalk. She was given oral prednisolone 30 mg daily, and her nausea and vomiting improved significantly, and the mandibular and ocular masses decreased in size.
CONCLUSIONS: Mikulicz\'s disease combined with IgG4-related hypophysitis is a rare case of IgG4-RD in elderly women. IgG4-RD is one of the causes of head and neck exocrine gland mass and pituitary stalk thickening in the elderly.

Constrictive pericarditis (CP) presents as a pathophysiological state where the pericardium becomes inelastic due to fibrotic changes, most commonly secondary to a protracted inflammatory process. The disease is characterized by compromised diastolic cardiac function due to loss of pericardial compliance. Immunoglobulin G4 (IgG4)-related disease, an entity marked by the insidious proliferation of IgG4-positive plasma cells and subsequent fibrosis within various organs, is an infrequent but recognized cause of CP. A case of a 55-year-old male patient with clinical manifestations of dyspnea and edema in the lower extremities elucidates the diagnostic complexity inherent to CP. Echocardiography revealed a constellation of signs, including annulus reversus, septal bounce, and a congested inferior vena cava; cardiac magnetic resonance imaging (MRI) demonstrated diffuse pericardial thickening with delayed gadolinium enhancement, suggestive of a long-term inflammatory state; and right heart catheterization confirmed the hemodynamic hallmark of CP-equalization of diastolic pressures across the cardiac chambers. The serological analysis elicited elevated serum levels of IgG4 and IgE, pointing to the differential diagnosis of IgG4-related disease. Given the nonspecific clinical presentation of IgG4-related CP, a heightened index of suspicion combined with a systematic approach to imaging and serological evaluation is paramount.

BACKGROUND: IgG4-related disease (IgG4-RD) is an immune-mediated systemic inflammatory fibrotic disease, which is a relatively rare and novel disease that can involve multiple organs or tissues, with variable clinical manifestations, and for which pulmonary involvement has been reported relatively infrequently.
METHODS: Here we report a case of pulmonary infection that was initially suspected and received anti-inflammatory treatment, but the symptoms did not improve. CT examination indicated progression of the pulmonary lesion, and the nature of the lesion could not be determined by tracheoscopy and bronchoalveolar lavage. The diagnosis of IgG4 related lung disease (IgG4-RLD) was confirmed by percutaneous lung biopsy. A joint literature analysis was conducted to improve clinicians\' understanding of this disease.
RESULTS: The patient\'s history, symptoms, signs and relevant examination results were analyzed. The final diagnosis was IgG4-RLD.
CONCLUSIONS: When the clinical symptoms and imaging manifestations of the patients are consistent with IgG4-RLD, pathological examination can be appropriately performed to clarify the nature of the lesions. More consideration should be given to the possibility of disease diagnosis to avoid misdiagnosis and underdiagnosis, and proper treatment should be given at an early stage.

Immunoglobulin G4 (IgG4)-related disease has the potential to impact any part of the body, including the walls of large- and medium-sized blood vessels and the ureters. While histopathologic examination is currently the standard method for identifying organ involvement and diagnosing IgG4-related disease (IgG4-RD), obtaining biopsy or surgical samples from vessel or ureteral walls is challenging. Given that patients may display only mild symptoms, non-invasive imaging plays a vital role in both diagnosing and managing IgG4-related diseases. Multidetector CT scans are valuable in establishing the primary diagnosis, identifying anatomical landmarks and assessing their relationships. Involvement of the genitourinary organs, such as the ureter, bladder, urethra, and male and female reproductive organs in IgG4-RD, is infrequent when compared to kidney involvement. The imaging findings may include the presence of a localised mass within or surrounding the affected organ or a generalised enlargement of the organ. This report includes cross-sectional images of five cases of IgG4-RD involving large- and medium-sized blood vessels (the aorta and superior mesenteric artery) and the ureters.
UNASSIGNED: This case series provides insight into the various imaging appearances of IgG4-related retroperitoneal organ involvement and helps differentiate it radiologically from retroperitoneal fibrosis.

BACKGROUND: Immunoglobulin G4-related disease is marked by extensive inflammation and fibrosis of an unknown autoimmune component, with an overall incidence ranging from 0.78 to 1.39 per 105 person-years. Sinonasal immunoglobulin G4-related disease is atypical and exceedingly uncommon in the existing literature, frequently manifesting clinically as chronic rhinosinusitis, epistaxis, and facial pain.
METHODS: This report describes a 25-year-old Iraqi female who has been suffering from symptoms of chronic rhinosinusitis for 8 years. Despite undergoing several surgeries, there has been no improvement in her symptoms. A tissue biopsy that revealed dense lymphoplasmocytosis with noticeable plasma cell infiltration, storiform fibrosis, and obliterative angitis, along with positive immunohistochemical staining for Immunoglobulin G4 plasma cells, finally confirmed the diagnosis of sinonasal immunoglobulin G4-related disease. The patient responded well to oral prednisolone and methotrexate treatments.
CONCLUSIONS: The main objective of the current report is to raise awareness among physicians about the significance of promptly identifying and diagnosing this rarity, thus preventing the adverse consequences linked to delayed diagnosis and treatment initiation.