A Viral Link to MS?
A recent study in JAMA (2003;289:1533-1536) suggests that Epstein-Barr virus (EBV) infection possibly plays a role in the etiology of multiple sclerosis (MS). Are there any ideas about how EBV or other pathogens might affect the development of MS? If so, what implications might these data have for drug discovery in the field?
Several studies have examined the relationship between viral infections and MS. Some were designed to explore the possibility that a virus causes MS, with others designed to evaluate possible associations, rather than causes.
EBV, human herpes virus-6 (HHV-6), measles, mumps, and the bacterial infection chlamydia have all been implicated as possible causes of or contributors to the development of MS. Investigators have found that parts of these viruses -- specifically protein sequences and how they are arranged -- closely mimic parts of the myelin sheath. These findings suggest the possibility that a viral infection such as EBV or HHV-6 could "misguide" the immune system into generating a response not only against the invading virus but also against the myelin sheath. This, in turn, might cause MS-like symptoms.
However, no study has determined that viral infections such as EBV or HHV-6 are unique to MS patients or are the cause of the disease. Work is ongoing in this intensely debated area of MS research. At this time, however, there is no evidence to conclusively support viral infection as a cause of MS or suggest antiviral therapies for the treatment of MS.
A recent study in JAMA (2003;289:1533-1536) suggests that Epstein-Barr virus (EBV) infection possibly plays a role in the etiology of multiple sclerosis (MS). Are there any ideas about how EBV or other pathogens might affect the development of MS? If so, what implications might these data have for drug discovery in the field?
Several studies have examined the relationship between viral infections and MS. Some were designed to explore the possibility that a virus causes MS, with others designed to evaluate possible associations, rather than causes.
EBV, human herpes virus-6 (HHV-6), measles, mumps, and the bacterial infection chlamydia have all been implicated as possible causes of or contributors to the development of MS. Investigators have found that parts of these viruses -- specifically protein sequences and how they are arranged -- closely mimic parts of the myelin sheath. These findings suggest the possibility that a viral infection such as EBV or HHV-6 could "misguide" the immune system into generating a response not only against the invading virus but also against the myelin sheath. This, in turn, might cause MS-like symptoms.
However, no study has determined that viral infections such as EBV or HHV-6 are unique to MS patients or are the cause of the disease. Work is ongoing in this intensely debated area of MS research. At this time, however, there is no evidence to conclusively support viral infection as a cause of MS or suggest antiviral therapies for the treatment of MS.
Source...