A New Cell Enzyme-Linked Immunosorbent Assay Demonstrates Gamma Interferon Suppression by Beta Interferon in Multiple Sclerosis

Multiple sclerosis (MS) is a demyelinating disorder of the central nervous system of unknown etiology. Immune mechanisms involving the proinflammatory cytokine gamma interferon (IFN-γ) are believed to play an important role in the pathogenesis of MS. IFN-β-1b has been introduced as a treatment for MS and was found to reduce the number and severity of clinical exacerbations. To examine the influence of IFN-β-1b on myelin basic protein (MBP)-specific and phytohemagglutinin-induced IFN-γ production, we developed a cell-released capturing enzyme-linked immunosorbent assay (CRC-ELISA), which rapidly measures spontaneous and antigen- or mitogen-induced cellular IFN-γ production. CRC-ELISA documented a significant MBP-specific T-cell response in the blood of untreated MS patients, as assessed by IFN-γ production. This response was suppressed in MS patients treated with IFN-β-1b. The present work confirms in vivo the in vitro suppressive effects of IFN-β-1b on IFN-γ production in MS. Moreover, it provides a powerful new technique for detection of cytokines.