IgG4 deficiency

BACKGROUND: Monoallelic loss-of-function IKZF1 (IKAROS) variants cause B-cell deficiency or combined immunodeficiency, whereas monoallelic gain-of-function IKZF1 variants have recently been reported to cause hypergammaglobulinemia, abnormal plasma cell differentiation, autoimmune and allergic manifestations, and infections. METHODS: We studied seven relatives with autoimmune/inflammatory diseases and lymphoproliferative diseases. We analysed biopsy results and performed whole-exome sequencing and immunological studies...

IgG4-related disease (IgG4-RD) has complex clinical manifestations ranging from fibrosis and inflammation to deregulated metabolism. The molecular mechanisms underpinning these phenotypes are unclear. In this study, by using IgG4-RD patient peripheral blood mononuclear cells (PBMCs), IgG4-RD cell lines and Usp25 knockout mice, we show that ubiquitin-specific protease 25 (USP25) engages in multiple pathways to regulate fibrotic and inflammatory pathways that are characteristic to IgG4-RD. Reduced USP25 expression in IgG4-RD leads to increased SMAD3 activation, which contributes to fibrosis and induces inflammation through the IL-1β inflammatory axis...

The prevalence of food allergy is rising and is estimated to approach 10%. Red meat allergy is the first known food allergy elicited by immunoglobulin E (IgE) antibodies recognizing a carbohydrate. Due to the loss of function of the alpha-1,3-galactosyltransferase ( GGTA1) gene in humans, the disaccharide galactose-α-1,3-galactose (α-Gal) cannot be synthesized and therefore became immunogenic. IgE sensitization is elicited through the skin by repetitive tick bites transmitting α-Gal. The underlying mechanisms regarding innate and adaptive immune cell activation, including the B-cell isotype switch to IgE, are poorly understood, requiring further research and physiologically relevant animal models...

BACKGROUND: This study investigated the safety and efficacy of an anti-CTLA-4 monoclonal antibody (CS1002) as monotherapy and in combination with an anti-PD-1 monoclonal antibody (CS1003) in patients with advanced/metastatic solid tumors. METHODS: The phase 1 study involved phase 1a monotherapy dose-escalation (part 1) and phase 1b combination therapy dose escalation (part 2) and expansion (part 3). Various dosing schedules of CS1002 (0.3, 1, or 3 mg/kg every 3 weeks, or 3 mg/kg every 9 weeks) were evaluated with 200 mg CS1003 every 3 weeks in part 3...

BACKGROUND AND AIM: Treating hemophilia A patients who develop inhibitors remains a clinical challenge. A mouse model of hemophilia A can be used to test the efficacy of strategies for inhibitor suppression, but the differences in the immune systems of mice and humans limit its utility. To address this shortcoming, we established a humanized NOD/SCID-IL2rγnull hemophilia A (hu-NSG-HA) mouse model with a severely deficient mouse immune system presenting a patient's adapted immune cells...

Immunoglobulin A (IgA) is acknowledged to play a role in the defence of the mucosal barrier by coating microorganisms. Surprisingly, IgA-deficient humans exhibit few infection-related complications, raising the question if the more specific IgG may help IgM in compensating for the lack of IgA. Here we employ a cohort of IgA-deficient humans, each paired with IgA-sufficient household members, to investigate multi-Ig bacterial coating. In IgA-deficient humans, IgM alone, and together with IgG, recapitulate coating of most bacterial families, despite an overall 3...

INTRODUCTION: Primary hypophysitis (PH) is a rare disease that represents a challenge among differential diagnosis and management. Our aim was to describe clinical characteristics, diagnostic criteria and different treatment outcomes in patients with PH. Multicentric, retrospective study. Clinical presentation, endocrine function, magnetic resonance imaging findings, visual field defects at diagnosis and treatment outcomes were recorded. METHODS: Twenty-eight patients (23 women), with PH were included...

Pozelimab (pozelimab-bbfg; VEOPOZ™) is a fully human immunoglobulin (Ig) G4P (i.e. IgG4 with a proline substitution to promote stabilization of the disulfide bonds between the two heavy chains) monoclonal antibody developed by Regeneron Pharmaceuticals Inc., to block the activity of complement factor 5 (C5) and prevent diseases mediated by the complement pathway. In August 2023, pozelimab received its first approval for the treatment of adults, and paediatric patients aged ≥ 1 year with CD55-deficient protein-losing enteropathy (PLE), also known as CHAPLE disease, in the USA...

Human immune system (HIS) mice provide a model to study human immune responses in vivo. Currently available HIS mouse models may harbor mouse Fc Receptor (FcR)-expressing cells that exert potent effector functions following administration of human Ig. Previous studies showed that ablation of the murine FcR gamma chain (FcRγ) results in loss of antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in vivo. We created a new FcRγ-deficient HIS mouse model to compare host (mouse) versus graft (human) effects underlying antibody-mediated immune responses in vivo...

OBJECTIVES: Ligneous conjunctivitis (LC) is a chronic conjunctivitis characterized by recurrent, firm, fibrin-rich, woody pseudomembranes on the palpebral conjunctiva. It is an ultrarare autosomal recessive disease associated with congenital plasminogen (PLG) deficiency due to mutations in the PLG gene (6q26). Immunoglobulin G4-related disease (IgG4-RD) is an idiopathic, systemic fibroinflammatory disease characterized by elevated serum IgG4 concentration and tissue infiltration of IgG4-positive plasma cells leading to organ enlargement, fibrosis and damage...

PURPOSE: To evaluate the functional and structural changes of the meibomian glands and ocular surface in immunoglobulin G4-related ophthalmic disease (IgG4-ROD) patients. DESIGN: Cross-sectional, matched case-control comparison study. METHODS: This study included 64 patients with biopsy-proven IgG4-ROD (aged 63.4 ± 12.2 years, 39 male) and 64 sex- and age-matched healthy controls. Patients were managed by hospitals covering the publicly funded ophthalmology service in Hong Kong...

No abstract text is available yet for this article.

A 65-year-old man presented with apparent bronchopneumonia. After treatment with antibiotics, he showed eosinophilia. Computed tomography (CT) imaging revealed bilateral consolidation, ground-glass opacities with nodular consolidations and pleural effusion. Lung biopsy showed organizing pneumonia with lymphoplasmacytic infiltration in alveolar septa and in thickened pleura and interlobular septa. All pulmonary abnormalities spontaneously went into remission within 12-months. At 73 years old, a follow-up CT scan revealed small nodules in both lungs and the review of head CT scan showed thickening of pituitary stalk in studying prolonged headache...

INTRODUCTION: Nutritional deficiencies, including fat-soluble vitamins and minerals have been detected in many autoimmune diseases, including those involving the digestive system, but have yet to be assessed in autoimmune pancreatitis (AIP). The aim of the present study was to determine the prevalence of micronutrient deficiencies in patients with AIP as well as to investigate their relationship with relapse. PATIENTS AND METHODS: We retrospectively analysed medical records of patients treated for AIP...

PURPOSE: Vitamin D (VitD) is an immunomodulatory molecule capable of alleviating allergic symptoms. However, the effectiveness of allergen-specific immunotherapy (AIT) is not commonly evidenced in the early build-up phase. The aim of the study was to determine the potential of VitD supplementation in this treatment phase. METHODS: Thirty-four house dust mite (HDM)-allergic adult patients treated with subcutaneous AIT were randomized to receive VitD2 60,000 IU/week or placebo for 10 weeks and followed up for 10 weeks...

Vaccinations for pathogenic organisms have been utilized for decades in both the protection and diagnosis of immunodeficiency patients. Some of these immunodeficient patients may not create an adequate response to vaccination, although some who have significant aberrancies in their immune system may surprisingly create antibodies to immunizations. We present a patient with a large Ig heavy chain deletion (severe deficiency of serum IgG1, IgG2, IgG4, and IgA1) that showed a considerable response (presumably through IgG3) after the Pfizer BioNTech COVID-19 vaccination...

DITRA, acronym for deficiency of interleukin-36 receptor antagonist (IL36RN), leads to unopposed pro-inflammatory signalling which typically manifests as pustular psoriasis. In Asian patients, c.115 + 6 T > C mutation is the most common and important single-nucleotide variant in DITRA. We present the largest case series consisting of 58 DITRA patients carrying heterozygous or homozygous c.115 + 6 T > C mutation. The mean age of onset (±SD) was 20...

Immune checkpoint blockers (ICB) act by reverting the immunosuppressive phenotype of cancer cells, thus allowing host immune system to generate an immune response to the tumor. One of the key mechanisms targeted by ICB is the PD-1/PD-L1 axis, which lies onto the interaction between the programmed-cell death protein 1 and its ligand, overexpressed in several tumor types. This interaction leads to the inhibition of T-cell proliferation and their apoptosis and exhaustion. Anti-PD-1/PD-L1 monoclonal antibodies are now the mainstay of treatment for several advanced stage tumors...

Salivary glands are physiologically orchestrated by the coordinated balance between cell differentiation, proliferation, apoptosis, and interactions between epithelial, mesenchymal endothelial, and neuronal cells, and they are frequent sites of manifestations of Sjögren's syndrome (SS) or IgG4-related disease (IgG4-RD). However, little is known about salivary gland homeostasis and its involvement in those diseases. Inhibitor of DNA binding/differentiation 4 (Id4) is an Id protein involved in the transcriptional control of many biological events, including differentiation...

Bilateral Sensorineural Hearing Loss is a rare disease that is often associated with other complex medical conditions. Primary central nervous system lymphoma is an uncommon and aggressive variant of non-Hodgkin lymphoma that can mimic many other neurological diseases. Herein, we present a rare case of lymphoma of the CNS as the etiology for progressive SSNHL. We describe a 58-year-old male with previous IgG4-disease presentation who was diagnosed with progressive sensorineural hearing loss. The condition evolved rapidly despite proper, conventional therapy...