A specific diagnostic metabolome signature in adult IgA vasculitis.

Introduction: IgA vasculitis diagnosis relies primarily on clinical features and is confirmed by pathological findings. To date, there is no reliable noninvasive diagnostic biomarker.

Objective: We aimed to explore the baseline serum metabolome of adult patients with IgA vasculitis to identify potential diagnostic biomarkers.

New insights into epidemiological data and impact of the COVID-19 pandemic on IgA vasculitis in children and adults: a French nationwide cohort.

IgA vasculitis (IgAV) is a small size vasculitis for which epidemiologic data are strikingly lacking, especially about the adult form. Additionally, the COVID-19 pandemic seems to have profoundly modified the incidence of this disease. Here, we aimed to establish some relevant epidemiological data in both pediatric and adult IgAV.

COVID-19 Vaccination as a Trigger of IgA Vasculitis: A Global Pharmacovigilance Study.

Objective: IgA vasculitis (IgAV) can occur after vaccination. We aimed to assess a potential safety signal on the association between coronavirus disease 2019 (COVID-19) vaccines and IgAV.

Methods: Cases of IgAV involving COVID-19 vaccines were retrieved in VigiBase.

IgA Vasculitis Following COVID-19 Vaccination: A French Multicenter Case Series Including 12 Patients.

Objective: The worldwide coronavirus disease 2019 (COVID-19) vaccination campaign triggered several autoimmune diseases. We hereby aimed to describe IgA vasculitis (IgAV) following COVID-19 vaccination.

Methods: We conducted a national, multicenter, retrospective study in France of new-onset adult IgAV diagnosis following COVID-19 vaccination.

Immunoglobulin A Vasculitis Following COVID-19: A French Multicenter Case Series.

Objective: Immunoglobulin A vasculitis (IgAV) usually occurs following viral respiratory tract infection. In the context of the global coronavirus disease 2019 (COVID-19) pandemic, we describe a case series of patients who developed IgAV following SARS-CoV-2 infection.

Methods: This national multicenter retrospective study included patients with IgAV following SARS-CoV-2 infection from January 1, 2020, to January 1, 2022.

Monoclonal Antibody Engineering and Design to Modulate FcRn Activities: A Comprehensive Review.

Understanding the biological mechanisms underlying the pH-dependent nature of FcRn binding, as well as the various factors influencing the affinity to FcRn, was concurrent with the arrival of the first recombinant IgG monoclonal antibodies (mAbs) and IgG Fc-fusion proteins in clinical practice. IgG Fc-FcRn became a central subject of interest for the development of these drugs for the comfort of patients and good clinical responses. In this review, we describe (i) mAb mutations close to and outside the FcRn binding site, increasing the affinity for FcRn at acidic pH and leading to enhanced mAb half-life and biodistribution, and (ii) mAb mutations increasing the affinity for FcRn at acidic and neutral pH, blocking FcRn binding and resulting, in vivo, in endogenous IgG degradation.

Towards better indications for kidney biopsy in adult IgA vasculitis: a clinical-laboratory and pathology correlation study.

Background: Indications for kidney biopsy in adult IgA vasculitis (IgAV) remain debated and there are very few studies on this subject. The aim of this study was to establish a correlation between renal histological and clinical-laboratory data.

Methods: A retrospective multicenter study was conducted using three databases from French hospitals, gathered between 1977 and 2020.

Neonatal Fc receptor expression in lymphoid and myeloid cells in systemic lupus erythematosus.

The neonatal Fc receptor (FcRn) is a ubiquitously expressed protein historically involved in IgG and albumin recycling. Recent data suggest an involvement in the pathophysiology of antibody-mediated autoimmune diseases. Among them, systemic lupus erythematosus (SLE) implies clinical and biological abnormalities of innate and adaptive circulating immune cells, potentially involving newly described functions of FcRn.

"Ways in which the neonatal Fc-receptor is involved in autoimmunity".

Since the neonatal IgG Fc receptor (FcRn) was discovered, its role has evolved from immunoglobulin recycling and biodistribution to antigen presentation and immune complex routing, bringing it to the center of both humoral and cellular immune responses. FcRn is thus involved in the pathophysiology of immune-related diseases such as cancer, infection, and autoimmune disorders. This review focuses on the role of FcRn in autoimmunity, based on the available data from both animal models and human studies.