AChR-blocking antibodies and complement system dynamics: evaluating their interplay and clinical implications in myasthenia gravis.

Background: Myasthenia gravis (MG) is an autoimmune disorder characterised by autoantibodies (abs) targeting proteins at the neuromuscular junction, primarily the acetylcholine receptor (AChR). While the role of AChR-binding abs is well-established, the pathogenicity and clinical relevance of AChR-blocking antibodies in MG, and their association with complement system, remain less understood.

Aims: This study aims to provide comprehensive insights into the prevalence and interplay of AChR-blocking antibodies and the complement system in an Argentinian MG cohort, investigating their relationships with disease activity.

C5a complement levels in clinical remission AQP4-IgG-positive NMO patients.

Background: Neuromyelitis Optica Spectrum Disorders (NMOSD) is an antibody-mediated disorder of the Central Nervous System where a leading role of the complement system has been demonstrated.

Objective: To measure the levels of complement factors C3, C4 and C5a in serum and plasma of clinical remission patients with AQP4-IgG + NMOSD.

Methods: Twelve patients with NMOSD AQP4 + according to 2015 criteria from a General Hospital in Buenos Aires, Argentina, were included in the study, and 19 age- and sex-matched healthy volunteers as a control group (HC).

Low Vitamin D Serum Levels in a Cohort of Myasthenia Gravis Patients in Argentina.

There are limited and controversial studies that address the role of vitamin D (vitD), a vitamin with immunomodulatory effects, in myasthenia gravis (MG), a neuromuscular autoimmune disease. We aimed to assess 25-hydroxy vitamin D (25(OH)D) levels and to evaluate possible associations with the clinical severity and other biomarkers of the disease. Serum levels of 25(OH)D, anti-acetylcholine receptor antibodies and complement factor C5a were measured in MG patients (n = 66) and healthy volunteers (HV) (n = 25).

C3, C5a and anti-acetylcholine receptor antibody as severity biomarkers in myasthenia gravis.

Background: Although the pathogenesis of myasthenia gravis (MG) is well known, prognostic markers are not yet available. We assessed the utility of anti-acetylcholine receptor (AChR) antibody (AChR-ab) titer and concentration of C3, C4, and C5a as potential severity biomarkers in MG.

Methods: Levels of C3, C4, C5a, and AChR-ab were measured in 60 AChR-ab-positive patients with MG.