Markus Reindl, Kathrin Schanda, Mark Woodhall, Fiona Tea, Sudarshini Ramanathan, Jessica Sagen, James P Fryer, John Mills, Bianca Teegen, Swantje Mindorf, Nora Ritter, Ulrike Krummrei, Winfried Stöcker, Juliane Eggert, Eoin P Flanagan, Melanie Ramberger, Harald Hegen, Kevin Rostasy, Thomas Berger, Maria Isabel Leite, Jacqueline Palace, Sarosh R Irani, Russell C Dale, Christian Probst, Monika Probst, Fabienne Brilot, Sean J Pittock, Patrick Waters,
OBJECTIVE:To compare the reproducibility of 11 antibody assays for immunoglobulin (Ig) G and IgM myelin oligodendrocyte glycoprotein antibodies (MOG-IgG and MOG-IgM) from 5 international centers. METHODS:The following samples were analyzed: MOG-IgG clearly positive sera (n = 39), MOG-IgG low positive sera (n = 39), borderline negative sera (n = 13), clearly negative sera (n = 40), and healthy blood donors (n = 30). As technical controls, 18 replicates (9 MOG-IgG positive and 9 negative) were included. All samples and controls were recoded, aliquoted, and distributed to the 5 testing centers, which performed the following antibody assays: 5 live and 1 fixed immunofluorescence cell-based assays (CBA-IF, 5 MOG-IgG, and 1 MOG-IgM), 3 live flow cytometry cell-based assays (CBA-FACS, all MOG-IgG), and 2 ELISAs (both MOG-IgG). RESULTS:We found excellent agreement (96%) between the live CBAs for MOG-IgG for samples previously identified as clearly positive or negative from 4 different national testing centers. The agreement was lower with fixed CBA-IF (90%), and the ELISA showed no concordance with CBAs for detection of human MOG-IgG. All CBAs showed excellent interassay reproducibility. The agreement of MOG-IgG CBAs for borderline negative (77%) and particularly low positive (33%) samples was less good. Finally, most samples from healthy blood donors (97%) were negative for MOG-IgG in all CBAs. CONCLUSIONS:Live MOG-IgG CBAs showed excellent agreement for high positive and negative samples at 3 international testing centers. Low positive samples were more frequently discordant than in a similar comparison of aquaporin-4 antibody assays. Further research is needed to improve international standardization for clinical care.
Neurol Neuroimmunol Neuroinflamm (Neurology(R) neuroimmunology & neuroinflammation)
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