Oligoclonal bands and quantitation of IgG in cerebrospinal fluid as indicators of multiple sclerosis.

The authors evaluated two laboratory procedures in respect to usefulness in evaluating patients suspected of having multiple sclerosis (MS). They classified 185 patients as having MS (MS-positive) or as not having MS (MS-negative). Agarose electrophoretic patterns of cerebrospinal fluid (CSF) samples were inspected for the presence of oligoclonal bands. CSF immunoglobulin G (IgG) was quantitated and compared with total CSF protein for 175 patients. Oligoclonal bands were present in specimens from 77% of the MS-positive group; elevated percentages of IgG (18% or more of total CSF protein) were present in specimens from 20%. Oligoclonal bands were present in specimens from 0.6% of the MS-negative group; elevated percentages of IgG were found for 1.4% of the MS-negative group. The presence or absence of oligoclonal bands in agarose electrophoretic patterns is sensitive (77%) and very specific (99%) in respect to MS. CSF IgG quantitation using the authors' criteria does not add useful information.