Objective: To investigate changes in serum complements and their regulators in the pathogenesis of myasthenia gravis (MG).
Methods: Forty-four patients with acetylcholine receptor antibody-positive MG, as well as 20 patients with non-inflammatory neurological disorders were enrolled. Serum complements (C3, C4 and soluble C5b-9) and complement regulators (vitronectin, clusterin and properdin) were extensively analysed by enzyme-linked immunosorbent assay and their associations with clinical profiles of MG were examined.
Results: Serum C3, C4 and clusterin levels were not significantly different between patients with MG and controls. The patients with MG had higher soluble C5b-9 (P = 0.09) and vitronectin (P = 0.001) levels than the controls; moreover, vitronectin levels decreased after treatment (P = 0.09). Serum properdin (P = 0.03) levels were lower in the patients with MG than in the controls, and negatively correlated with the MG Activities of Daily Living score (rs = -0.26, P = 0.09) and with the presence of bulbar palsy (P = 0.04).
Conclusion: Our results show that activation of complements and an altered complement network could contribute to the inflammatory pathogenesis of MG.
Keywords: complement regulators; complements; myasthenia gravis.
© 2020 European Academy of Neurology.