Spleen versus CNS immunoglobulin G in multiple sclerosis: an isoelectric focusing study

Immunoglobulin G (IgG) band patterns were investigated in a peripheral immune compartment, the spleen, and the central nervous system (CNS) compartment in 6 multiple sclerosis (MS) subjects and 3 controls in a search for systemic humoral immune response that may be related to the localized immune response seen in MS. Using the isoelectric focusing (IEF) technique with immunoperoxidase staining of proteins transferred to nitrocellulose membranes, we were not able to demonstrate any qualitative abnormalities of spleen or serum IgG in the MS cases, whilst all matched CNS tissues and CSF specimens were clearly positive for oligo-clonal IgG bands. Our results suggest that there is no systemic oligoclonal IgG secretion in MS. This further supports the presence of a compartmentalized IgG intrathecal immune response in MS and emphasizes the organ specificity of MS.