Jan 03, 2003
Results of a study published in the January issue of the Journal of Medical Virology suggest that HHV-6 reactivation plays a role in the exacerbation of multiple sclerosis (MS).
Dr. Svetlana Chapenko, of the University of Latvia, in Riga, and colleagues examined the relationship between HHV-6 infection and MS, and between HHV-6 reactivation and MS disease activity.
In 26 patients with MS, the investigators evaluated the frequency of HHV-6 genomic sequences in peripheral blood mononuclear cells (PBMCs), the incidence of plasma viremia, the transcription of viral mRNA in PBMCs and the presence of antiviral IgM and IgG plasma antibodies.
Clinical manifestations of MS, brain MRIs, and serum interleukin (IL)-12 concentrations were also evaluated. Another 21 patients with other neurologic disorders and 150 blood donors were also examined.
Of 26 the patients with MS, 16 (61.5%) had HHV-6 infection, compared with 6 of 21 patients (28.6%) with other neurological diseases and 42 of 150 (28.7%) blood donors. Ten of 13 MS patients (76.9%) showed clinical and MRI activity that occurred simultaneously with HHV-6 reactivation, according the authors.
Among patients with active MS disease, those with active HHV-6 infection had significantly higher serum concentrations of IL-12 than those with latent infection. "The data confirm an association between HHV-6 infection and MS and show a correlation between HHV-6 reactivation and disease activity in relapsing/remitting and secondary progressive MS," Dr. Chapenko and colleagues write.
Compared with patients with latent HHV-6 infection, those with active infection were at significantly higher risk (p < 0.005) of an exacerbation of MS. HHV-6 reactivation correlated with serum IL-12 concentration during disease activity, the team notes.
J Med Virol 2003;69:111-117.
© 2003 Reuters Ltd