Neonatal Fc receptor blockade as emerging therapy in diseases with plasma exchange indications

Neonatal Fc receptor (FcRn) blockade may represent a mechanism similar to plasma exchange (PLEX) in reducing immunoglobulin levels and thus have a broad implication for apheresis practitioners. Although only efgartigimod received FDA approval for myasthenia gravis in December 2021, multiple trials are currently underway with different FcRn therapies in a varied group of IgG antibody-mediated neurological and hematological disorders which are outlined in this review. In this review we discuss FcRn's mechanism of action, and its potential use in various neurological and non-neurological diseases. In addition, we further compare the kinetics and adverse events of PLEX and FcRn blockade. We encourage apheresis practitioners to be familiar with this class of drugs in order to better understand how these two therapies can be used either standalone, or in combination with other therapies as both FcRn antagonism and PLEX improve clinical state by reducing IgG levels and pathogenic antibodies.