Cell based assays (CBAs) for immunoglobulin G antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) show excellent agreement on clear positive and negative samples, where live cells expressing full-length human MOG are used as the assay substrate. However, agreement between low positive samples was more discordant; further research is required to determine and standardize the most clinically useful assay cutoff point.
Why this matters
Use of full-length human MOG as an assay substrate has been shown to clearly discriminate between various central nervous system (CNS) disorders and multiple sclerosis (MS). This has driven the proliferation of different MOG-IgG CBAs being used to measure MOG-IgG in various international research centers.
Data on assay agreement and reproducibility between centers is limited. This study provides justification for future research on assay standardization, assay cutoff definition and utility of further research on patients with low MOG-IgG counts.