Immune complexes in serum and cerebrospinal fluid of multiple sclerosis patients and patients with other neurological diseases.

Paired serum and cerebrospinal fluid (CSF) specimens from 30 multiple sclerosis (MS) patients and 30 patients with other neurological diseases (ONDs) were analyzed for the presence of immune complexes (ICs). With each of the 4 tests used, ICs were found more frequently in sera from both MS and OND patients than in sera from healthy blood donors. IC-positivity for MS and OND patient CSF varied from 10-33% and from 10-17% in different tests. The number of IC-positive sera or CSF in MS patients did not differ significantly from those in OND patients. For both MS and OND patients, the positivity pattern for serum and CSF specimens in each IC test was essentially unique. Furthermore, because several CSF IC-positive and serum IC-negative paired specimens were found, intrathecal IC formation may be independent of IC formation in peripheral blood. The presence of ICs in serum or CSF did not correlate with the clinical status of or laboratory data on the MS patients, nor was a correlation found with the diagnosis of the OND patients. In total, these results suggest that the presence or absence of ICs in MS or OND patients may simply reflect changes in the immunological regulation of individual patients.