Multiplexing analysis of the polyspecific intrathecal immune response in multiple sclerosis.

Intrathecal synthesis of the antibodies specific to neurotrofic viruses: measles (M), rubella (R), Varicella-Zoster (Z), and/or H. simplex (H), known as "MRZH-reaction" plays important diagnostic role in multiple sclerosis (MS). Whereas the analysis of the oligoclonal IgG bands provides high sensitivity, the MRZH-reaction shows high specificity, and hence these methods complement each other. For the first time we applied multiplexing bead-based technology to simultaneously analyze cerebrospinal fluid (CSF) and serum concentrations of antibodies against these viruses, and to calculate the antibody specific indices (ASI's). The method shows reasonable precision: intra-assay, 2.9-6.7%, and inter-assay, 2.0-3.2%. The results are comparable with these obtained with other methods (ELISAs), including two runs of the certified external quality control schemes. Eighty-one percent of the MS cases (n=27) and none of the sex- and age-matched controls (n=14), except one subject with "borderline" anti-measles ASI of 1.5, showed intrathecal synthesis of IgG against at least one of the viruses discussed. The ratios of the MRZH-positive cases in the MS group were: 12/22 for M, 12/19 for R, 13/26 for Z, and 7/26 for H. We conclude that the multiplexing technology can be applied as a tool to study the intrathecal immune response in the diagnosis of MS.