Oligoclonal bands are found in electrophoretograms of serum of patients with multiple sclerosis.

A recent paper (1) describing oligoclonal banding in CSF indicates that it is necessary to electrophorese paired CSF and serum specimens simultaneously, to differentiate oligoclonal banding caused by intrathecal iinmunoglobulun production from increased permeability of the blood-CSF barrier. This dogma is not correct, as it has been shown by use of polyacrylaimde gel isoelectric focusing and Coomassie Briffiant Blue staining or agarose gel electrophoresis that 74% and 9%, respectively, of patients with multiple sclerosis having oligoclonal bands in the CSF patterns also had bands in the corresponding patterns for serum (2). These bands were not seen in patterns for normal CSF and normal serum (2). We have investigated the frequency of oligoclonal banding in sera of patients with multiple sclerosis by using agarose isoelectric focusing, staining with silver. In our group of 12 patients with multiple sclerosis, bands were present in the sera of 11. Paired electrophoretograms of CSF and serum showed that the oligoclonal bands in both had identical electrophoretic mebilities. Just why the oligoclonal bands are present in the patterns for sera of patients with multiple sclerosis has not been determined, but if the criterion of oligoclonal bands in CSF and not in serum is used to determine clinical significance, this may lead to falsenegative results.