We examined Cerebral Spinal Fluid (CSF) from Multiple Sclerosis (MS) patients and patients with Other Neurological Diseases (OND) for Antibody specific for Human HerpesVirus-6 (HHV-6) and for HHV-6 DNA detectable by PCR.
CSF from MS patients had a higher frequency of IgG Antibody to HHV-6 late Antigens (39.4%) compared with CSF from OND (7.4%). In contrast, the frequency of detectable IgG Antibody in CSF from MS patients specific for Epstein-Barr Virus (EBV) (12.1%) and Human Cytomegalovirus (HCMV) (6.1%) was much lower.
Two of 12 MS CSFs (16.7%) also contained HHV-6 DNA detected by PCR. None of four OND CSF were positive for HHV-6 DNA. Plasma from 16 patients with MS, eight with OND and 72 healthy donors were tested for AntiBodies by ELISA to HHV-6 early (p41/38) and late (gp110) proteins.
Although no differences in anti-gp110 IgG Antibody were detected between MS patients, patients with Other Neurological Diseases, and normals, IgG AntiBody to early protein p41/38 was detected in > 68% of the Plasma from MS patients, 12.5% from OND patients and 27.8% of the controls.
IgM Antibody to p41/38 was present in > 56% of MS patients, 12.5% of OND patients, and 19% of controls. These data suggest that more than half of the MS patients had active, ongoing HHV-6 infections.
HHV-6 was also isolated from Peripheral Blood MonoNuclear Cells (PBMC) from 3/5 MS patients who were in relapse or had Progressive MS disease and was identified as HHV-6 Variant B.
These preliminary results support the hypothesis that HHV-6 may be a co-factor in the PathoGenesis of some cases of MS.