Detection of myelin autoantibodies: evaluation of an assay system for diagnosis of multiple sclerosis in differentiation from other central nervous system diseases.

BACKGROUND: Multiple sclerosis (MS) is a frequent and often severe autoimmune disease of the central nervous system. We describe a newly developed enzyme-linked immunosorbent assay (ELISA)-based test system for the assessment of neuronal autoantibodies in serum and cerebrospinal fluid (CSF). This tool could help define autoimmune status and thus be a potential means of therapeutic surveillance. METHODS: We used an assay system (ELISA, E100, Mediagnost) based on purified bovine antigens [myelin-oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), myelin-associated glycoprotein (MAG), proteolipid protein (PLP) and alpha-B-crystalline (CRY)] antibodies for the measurement of specific immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies. Assay characteristics and preliminary validation were conducted by measurement of serum and CSF samples from 41 MS patients and 128 patients with other neurological diseases (OND). RESULTS: We measured the inter- (17.8/10.1%) and intra-assay variability (5.5/6.7%); linearity (1:250- 1:16,000), and specificity of IgG and IgM. We demonstrate that by the results of this test system MS patients can be differentiated from patients with OND. CONCLUSIONS: The ELISA kit we evaluated is suitable for the measurement of neuronal autoantibodies. The initial validation demonstrates its potential use in the differential diagnosis of central neuronal system diseases.