HHV-6 status determines effectiveness of interferon treatment in Multiple Sclerosis

The administration of immune agents to patients (known as Interferon-Beta-1b, or IFN-beta, therapy) has been widely used in the treatment and maintenance of multiple sclerosis (MS). Additionally, it is known that the risk of MS exacerbation is much higher in patients with active HHV-6 infection than in patients with a latent infection of the virus (Lafuente 2006, 2007; Chapenko 2003).

In this new study from Madrid, researchers examined the effectiveness of IFN-1b therapy in multiple sclerosis patients with active HHV-6 infection. By monitoring the HHV-6 DNA levels of MS patients undergoing IFN-beta therapy, investigators were able to find that patients with active HHV-6 infection had a higher risk of severe MS relapse and poor response to IFN-beta therapy than patients without active HHV-6 infection. The increased frequency of MS exacerbation among patients with active HHV-6 infection is thought to be attributed to a reaction of the body’s immune system against the active replication of HHV-6 virus, which is supported by results from the study that show active HHV-6 replication is more frequent during relapses of MS than during remission. The active replication of Epstein-Barr Virus—another infectious agent that has long been associated with multiple sclerosis—however, was not associated with any clinical parameters among MS patients in this study. These findings suggest that the presence of active HHV-6 in the blood and serum of patients undergoing IFN-beta may be a good indicator of poor response to this treatment option for multiple sclerosis patients. Go to the abstract on PubMed.