CONTEXT: Human herpesvirus 6 (HHV-6) has been linked with multiple sclerosis (MS). OBJECTIVES: To determine HHV-6 viral load in patients with MS, and to analyze separately its 2 variants, HHV-6A and HHV-6B. PATIENTS AND METHODS: We analyzed 149 blood and serum samples; 103 were from patients with relapsing-remitting MS (33 during an MS relapse and 70 during remission), and 46 were from healthy blood donors. To determine whether the HHV-6 genome and its variants were present, we analyzed viral DNA using quantitative real-time polymerase chain reaction, which has a sensitivity of 1 copy. RESULTS: We found HHV-6 DNA in the peripheral blood mononuclear cells of 53.4% of patients and 30.4% of healthy blood donors; HHV-6A was found in 20.4% of patients and 4.4% of controls, and HHV-6B was found in 33.0% vs 26.1%, respectively. Mean viral load in both groups was 7.4 copies of HHV-6 per microgram of DNA (range, 1-15 copies). Analysis of serum samples showed that none of the healthy blood donors were positive for HHV-6, although 14.6% of patients were positive for the virus, specifically the HHV-6A variant. There was no difference between patients during remission or relapse. Mean viral load was 26.3 copies/microg microgram of DNA (range, 1-86 copies). CONCLUSIONS: Despite the low viral load and the lack of clinical correlation, and given the biological characteristics of the virus, our results suggest that there was active HHV-6A infection in 14.6% of patients with MS. Further quantitative real-time polymerase chain reaction studies will help us understand the clinical significance of such a low viral load.
CONTEXT: Human herpesvirus 6 (HHV-6) has been linked with multiple sclerosis (MS). OBJECTIVES: To determine HHV-6 viral load in patients with MS, and to analyze separately its 2 variants, HHV-6A and HHV-6B. PATIENTS AND METHODS: We analyzed 149 blood and serum samples; 103 were from patients with relapsing-remitting MS (33 during an MS relapse and 70 during remission), and 46 were from healthy blood donors. To determine whether the HHV-6 genome and its variants were present, we analyzed viral DNA using quantitative real-time polymerase chain reaction, which has a sensitivity of 1 copy. RESULTS: We found HHV-6 DNA in the peripheral blood mononuclear cells of 53.4% of patients and 30.4% of healthy blood donors; HHV-6A was found in 20.4% of patients and 4.4% of controls, and HHV-6B was found in 33.0% vs 26.1%, respectively. Mean viral load in both groups was 7.4 copies of HHV-6 per microgram of DNA (range, 1-15 copies). Analysis of serum samples showed that none of the healthy blood donors were positive for HHV-6, although 14.6% of patients were positive for the virus, specifically the HHV-6A variant. There was no difference between patients during remission or relapse. Mean viral load was 26.3 copies/microg microgram of DNA (range, 1-86 copies). CONCLUSIONS: Despite the low viral load and the lack of clinical correlation, and given the biological characteristics of the virus, our results suggest that there was active HHV-6A infection in 14.6% of patients with MS. Further quantitative real-time polymerase chain reaction studies will help us understand the clinical significance of such a low viral load.
Authors: Michael K Axthelm; Dennis N Bourdette; Gail H Marracci; Weiping Su; Elizabeth T Mullaney; Minsha Manoharan; Steven G Kohama; Jim Pollaro; Ellen Witkowski; Paul Wang; William D Rooney; Lawrence S Sherman; Scott W Wong Journal: Ann Neurol Date: 2011-06-14 Impact factor: 10.422
Authors: P P Banerjee; L Pang; S S Soldan; S M Miah; A Eisenberg; S Maru; A Waldman; E A Smith; Y Rosenberg-Hasson; D Hirschberg; A Smith; D V Ablashi; K S Campbell; J S Orange Journal: Mol Immunol Date: 2018-11-24 Impact factor: 4.407
Authors: William H Theodore; Leon Epstein; William D Gaillard; Shlomo Shinnar; Mark S Wainwright; Steven Jacobson Journal: Epilepsia Date: 2008-07-08 Impact factor: 5.864
Authors: Marta Garcia-Montojo; Virginia De Las Heras; Manuel Bartolome; Rafael Arroyo; Roberto Alvarez-Lafuente Journal: J Neurovirol Date: 2007-12 Impact factor: 2.643