Functional Signature of LRP4 Antibodies in Myasthenia Gravis

Abstract

Background and Objectives

Antibodies (Abs) specific for the low‐density lipoprotein receptor-related protein 4 (LRP4) occur in up to 5% of patients with myasthenia gravis (MG). The objective of this study was to profile LRP4-Ab effector actions.

Methods

We evaluated the efficacy of LRP4-specific compared with AChR-specific IgG to induce Abdependent cellular phagocytosis (ADCP), Ab-dependent cellular cytotoxicity (ADCC), and Ab-dependent complement deposition (ADCD). Functional features were additionally assessed in an independent AChR-Ab+ MG cohort. Levels of circulating activated complement proteins and frequency of Fc glycovariants were quantified and compared with demographically matched 19 healthy controls.