Oligoclonal bands in cerebrospinal fluids: significance of corresponding bands in serum for diagnosis of multiple sclerosis.

Controversy exists regarding the definition of oligoclonal bands in cerebrospinal fluid (CSF) and whether CSF bands with corresponding bands in the serum should be disregarded in the interpretation. Much of this controversy results from not distinguishing between the sensitivities of different techniques used for these studies. Because the combination isoelectric focusing/silver staining is more sensitive than agarose gel electrophoresis/Coomassie Blue staining for detecting weak bands, one would expect to find weak oligoclonal bands in the serum more frequently with the former technique than the latter. Yet, most clinical laboratories use agarose gel electrophoresis for this assay. To investigate the clinical relevance of CSF oligoclonal bands as compared with corresponding bands for serum by electrophoresis on agarose gel, we retrospectively reviewed paired CSF and serum electrophoretograms of 104 patients. We determined that the specificity of the oligoclonal-band test for diagnosis of multiple sclerosis was significantly enhanced by running paired CSF and serum specimens when CSF bands with corresponding serum bands were discounted.