Friday, 18 November 2011

Herpes virus 6 linked to MS relapses

Epub ahead of print: Simpson et al. Anti-HHV-6 IgG titer significantly predicts subsequent relapse risk in multiple sclerosis. Mult Scler. 2011 Nov 14.

Background: Some of the strongest associations with MS onset are for human herpesviruses, particularly Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6). Their role in MS clinical course is less clear, however.

Methods: Prospective cohort of 198 persons with clinically definite MS, followed 2002-5, and serum samples obtained from all subjects at study entry to measure anti-HHV-6 and anti-EBV (Epstein-Barr nuclear antigen [EBNA] and viral capsid antigen [VCA]) antibody Immunoglublin G (IgG) levels (titers).


Results: For the 145 persons with RRMS followed beyond one review, anti-HHV-6 IgG titer was positively associated with the hazard of relapse with a dose-dependent trend (p = 0.003), not affected by adjustment for anti-EBV IgG titers, neither of which were independently associated with relapse. There was no significant association between anti-human herpesvirus IgG titers and baseline-measured disability scores, or change in disability scores; however, anti-HHV-6 IgG titers were 2.8 times higher among progressive-course females than progressive-course males.

Discussion: These findings suggest that, in addition to a potential etiological role in MS, HHV-6 infection or the immune response to HHV-6 antigens may have an effect on the risk of MS relapses and possibly on progressive courses of MS. The observed effect was directly related to anti-HHV-6 IgG titers and may indicate that either HHV-6 infection or factors associated with an altered humoral immune response to HHV-6 may have an effect on MS clinical course. Anti-HHV-6 IgG titer may be a useful factor in assessing the course of relapsing-remitting MS clinical course.

HHV6 is another common virus that may of us are exposed to. It further adds to the belief that relapses often follow (upper respiratory tract-lung) infections

"The problem I have with this study is that antibodies to HHV-6 actually recognise two different viruses called HHV-6A and HHV-6B; these viruses although similar to each other are different. What virus is therefore responsible for this association?"

"How does this tie in with the EBV hypothesis? Could other herpes viruses be linked to MS? These questions all need answering and I think about them a lot."

6 comments:

  1. Isn't this why acyclovir was tested as a treatment for RRMS 15 years ago? What happened to that line of reasoning?

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  2. Re: "Isn't this why acyclovir was tested as a treatment for RRMS 15 years ago? What happened to that line of reasoning?"

    Yes and no. Acyclovir was tried to target herpes simplex virus rather than HHV-6; it does not have much activity against HHV-6 or EBV for that matter. We need better anti-virals; interestingly some exist. Watch this space.

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  3. Re: the potential etiological role of HHV-6 in MS.

    Is this a case of cross-reactivity whereby some of the peptides of the HHV-6 antigen are similar those of myelin, thus initiating an autoimmune response? Have there been any studies done looking into a possible association between MS and HHV‑1? I've never had mono but I did and do have an occasional outbreak of cold sores.

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  4. If there is a viral link perhaps it could be of use to test HIV drugs on people with MS?

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  5. Dear Anon 9:58

    Maybe

    Could antiretroviral drugs be effective in multiple sclerosis? A case report. Maruszak H, Brew BJ, Giovannoni G, Gold J.Eur J Neurol. 2011;18:e110-1.

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  6. Before you ever have an outbreak. Then, if you have had several partners, then there is no way to know exactly whom it was you contracted it from. It is estimated that one-third to one-half of the population has some form of the herpes virus.

    ReplyDelete

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