Viral activity in MSers

#MSBlog: HHV6: a herpes virus that keeps popping up in MSers!

Epub: Ramroodi et al. Monitoring of active human herpes virus 6 infection in Iranian patients with different subtypes of multiple sclerosis J Pathog. 2013;2013:194932. doi: 10.1155/2013/194932. 

Background: Recently, it has been suggested that human herpes virus 6 (HHV6) may play a role in the pathogenesis of multiple sclerosis (MS). 

Purpose: To determine the incidence of reactivated HHV6 in MSers.

Methods: Viral sequence analyzed by qPCR in the peripheral blood mononuclear cells (PBMCs), serum, and saliva samples of different subtypes of MSers (n = 78) and healthy controls (n = 123). HHV6 IgG and IgM antibody levels measured by ELISA technique in the plasma samples of both groups. Likewise, cerebrospinal fluid (CSF) samples of some MSers (n = 38) were analyzed for viral sequence.

Results: Results demonstrate increased levels of anti-HHV6-IgG (78.2% versus 76.4% in controls; P = NS), and IgM (34.6% versus 6.5% in controls; P < 0.05) in MSers. Furthermore, RRMS and SPMS MSers showed relatively higher anti-HHV6 IgG and IgM compared to PPMS (P < 0.001). Moreover, load of cell-free viral DNA was higher in RRMS and SPMS patients and detected in 60.2% (47/78) of MSers, compared with 14.6% (18/123) of healthy controls (P < 0.001). Moreover, load of cell-free viral DNA was higher in RRMS and SPMSers and detected in 60.2% (47/78) of MSers, compared with 14.6% (18/123) of healthy controls (P < 0.001).

Conclusions: The results extend the observation of an increased frequency of systemic reactivated HHV6 infection in MS patients with developed stages of disease.

HHV6
"This study is very difficult to interpret as HHV6 is actually a family of 2 viruses; A & B. These viruses have a completely different biology and the assay that detects antibodies to these viruses cannot distinguish between the A or the B virus. What is interesting is that MSers had higher cell-free load of HHV6 implying that the virus was more likely to be actively replicating in MSers than controls. One of the hypotheses we are working on is that human endogenous retroviruses are pathogenic by transactivating latent herpes viruses; HHV6 being one of them. Our Charcot project is looking at a drug that suppresses HERVs. It will be interesting to see in our trial if this strategy reduces HHV6 expression."

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