Journal: Journal of Clinical Virology, Vol. 37, Supplement I, December 2006, pg. S116. [Supplement sponsored by HHV-6 Foundation. E-Publication Jan 10. 2007. Full text is available for a fee at http://www.sciencedirect.com/science/journal/13866532 ] Authors and affiliation: K.K. Knox, D.R. Carrigan. Institute for Viral Pathogenesis, Milwaukee, Wisconsin, USA. [E-mail: firstname.lastname@example.org ]
Background: Data from a number of laboratories have implicated HHV-6 as being involved in the pathogenesis of CFS and MS.
Objectives: The study described here focuses on the use of various diagnostic technologies to compare the incidence of active HHV-6 infections in MS patients, patients with CFS and healthy control subjects.
Study Design: Blood samples were obtained from four groups: 1. A cross-section of CFS patients, 2. Patients with relapsing-remitting MS at the time of clinical relapse, 3. The same MS patients after the relapse had resolved, and 4. Healthy control subjects. Blood leukocytes were assessed for active HHV-6 infection by a rapid culture assay and by an HHV-6 specific antigenemia assay. Plasma samples were analyzed by a nested HHV-6 PCR technique.
Results: See the Table Healthy Controls
n Rapid HHV-6 culture: 2% (1/55)
n HHV-6 antigenemia: 7% (4/55)
n Nested Plasma PCR: 0% (0/68) CFS Patients
n Rapid HHV-6 culture: 25% (20/81) p<0.0002 (comparison to healthy controls by Fisher’s Two-sided Exact Test)
n HHV-6 antigenemia: 31%(25/81) p<0.001
n Nested Plasma PCR: 22% (11/49) p<0.0001 MS at relapse
n Rapid HHV-6 culture: 48% (15/31) p<0.0001
n HHV-6 antigenemia: 45% (14/31) p<0.0001
n Nested Plasma PCR: 24% (6/25) p<0.0002
MS after relapse
n Rapid HHV-6 culture: 19% (6/31) p<0.008
n HHV-6 antigenemia: 10% (3/31) Not significant
n Nested Plasma PCR: 11% (3/28) p<0.03
Conclusions: There exists a subpopulation of CFS patients who have chronic, active infections with HHV-6. This subset of CFS patients is remarkably similar to patients with relapsing-remitting MS with respect to their active HHV-6 infections. Diagnosis of such HHV-6 infections is most effectively achieved by the use of two complementary procedures, i.e. nested PCR with plasma or serum samples and rapid culture/antigenemia using patient blood leukocytes.