[P1-117] The rapid and quantitative anti-MOG autoantibody assay using flow cytometry
[Introduction] Autoantibody against myelin oligodendrocyte glycoprotein (MOG) is often detected in patients with various demyelinating syndromes. We tried to develop the flow cytometry analysis of anti-MOG autoantibody based on the cell-based assay. [Methodology] We generated the cell line expressing fused protein of human MOGα1 and green fluorescent protein (GFP) on the cell surface. Cells were incubated with diluted sera or cerebrospinal fluids (CSF) from 59 patients with demyelinating or non-demyelinating diseases, followed by reaction with Alexa-fluor 647 conjugated anti-human IgG antibody. The titer of anti-MOG antibody was measured as a mean fluorescent intensity (MFI) by flow cytometry. In addition, we attempted to measure the absolute titer of antibody by using standard curve from a commercial anti-MOG monoclonal antibody (8-18C5). [Results] We detected high MFI, which shows high anti-MOG antibody titer, only in 8 patients of demyelinating diseases (both serum and CSF), but in none of non-demyelinating diseases. There was a correlation between the clinical course and antibody titer in one patient. The standard curve of 8-18C5 was always valid and seemed to quantify the antibody titer accurately in the individual tests, but showed some variation between assays. [Conclusions] Flow cytometry analysis of anti-MOG antibody is useful because it enables us to analyze the antibody more rapidly and more objectively than the usual cell-based immunocytochemistry. We are trying to produce anti-MOG antibody from the human B cell-derived hybridoma and use it for drawing standard curve, which is anticipated to improve the quantitative variation.