Complement factors C3, C4 and C5a in Myasthenia Gravis: looking for a potential disease activity marker

MANIN A; JUSTO ME; VILLA A; AGUIRRE F; MANUELLI PN; PAZ ML; LEONI J; FERNANDEZ VC; GONZÁLEZ MAGLIO DH

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencias, LXV Reunión Anual Sociedad Argentina de Inmunología; 2017

Myasthenia Gravis (MG) is an autoantibody-mediated pathology. Many of these autoantibodies bind to the acetylcholine receptor in the neuromuscular junction, activating the complement system, thus generating damage and muscle weakness. We aimed to measure C3, C4 and C5a concentration in MG patients, and to analyze their potential as disease activity markers. We collected 63 samples from MG diagnosed patients (17 exacerbated) and normal matching controls (nc). There were 11 cases of paired samples. Disease status (remission: rem or exacerbation: ex) was determined by neurologic evaluation. We quantified C5a using a home-setup ELISA (expecting increases). C3 and C4 were measured with commercial radial immunodifussion plates (expecting decreases). There were no statistically significant (ss) differences in C3 and C4 mean values between groups (rem, ex, nc). But there was a ss correlation between C3 and C4 values in the 63 samples. This correlation was strong (r2=0.9) in the group of patients in an ex period (p