BACKGROUND: Although the etiology of multiple sclerosis (MS) remains uncertain, clinical, epidemiological, and laboratory findings suggest that environmental factors may be involved in the disease. OBJECTIVE: This study was undertaken in order to investigate the possible relation of human herpesvirus-6 (HHV-6) in relapsing-remitting MS (RRMS). STUDY DESIGN: A one-year follow-up study was performed analyzing serum samples of 63 patients with RRMS and 63 healthy blood donors (HBD) by a quantitative real time PCR, to measure HHV-6 prevalence and viral load. Clinical data (starting age and EDSS increase) were collected. RESULTS: (i) We found 25.4% of RRMS patients with at least one positive serum sample along the one year follow-up. (ii) 19.1% of RRMS samples in relapse had HHV-6 active infection vs. 7.9% of RRMS samples in remission. (iii) We only found variant A. (iv) RRMS patients with HHV-6 active replication initiated the disease 1.9 years earlier, and they had a higher EDSS increase. CONCLUSIONS: A higher HHV-6A frequency of active infection seems to be related with the exacerbations in a subset of RRMS patients. Regarding the relationship between HHV-6A active infection and the clinical data in RRMS patients, further investigations are needed.
BACKGROUND: Although the etiology of multiple sclerosis (MS) remains uncertain, clinical, epidemiological, and laboratory findings suggest that environmental factors may be involved in the disease. OBJECTIVE: This study was undertaken in order to investigate the possible relation of human herpesvirus-6 (HHV-6) in relapsing-remitting MS (RRMS). STUDY DESIGN: A one-year follow-up study was performed analyzing serum samples of 63 patients with RRMS and 63 healthy blood donors (HBD) by a quantitative real time PCR, to measure HHV-6 prevalence and viral load. Clinical data (starting age and EDSS increase) were collected. RESULTS: (i) We found 25.4% of RRMS patients with at least one positive serum sample along the one year follow-up. (ii) 19.1% of RRMS samples in relapse had HHV-6 active infection vs. 7.9% of RRMS samples in remission. (iii) We only found variant A. (iv) RRMS patients with HHV-6 active replication initiated the disease 1.9 years earlier, and they had a higher EDSS increase. CONCLUSIONS: A higher HHV-6A frequency of active infection seems to be related with the exacerbations in a subset of RRMS patients. Regarding the relationship between HHV-6A active infection and the clinical data in RRMS patients, further investigations are needed.
Authors: Dharam Ablashi; Henri Agut; Roberto Alvarez-Lafuente; Duncan A Clark; Stephen Dewhurst; Dario DiLuca; Louis Flamand; Niza Frenkel; Robert Gallo; Ursula A Gompels; Per Höllsberg; Steven Jacobson; Mario Luppi; Paolo Lusso; Mauro Malnati; Peter Medveczky; Yasuko Mori; Philip E Pellett; Joshua C Pritchett; Koichi Yamanishi; Tetsushi Yoshikawa Journal: Arch Virol Date: 2013-11-06 Impact factor: 2.574