Relapsing-Remitting Multiple Sclerosis and Human Herpesvirus 6 Active Infection

Abstract

The results show that a subset of patients with RRMS experience HHV-6 active infection, and there likely is an association between the viral active replication and relapses; therefore, HHV-6 active infection may imply a greater risk of exacerbations in a subgroup of patients with RRMS.

Members 6B and 14 of the TNF receptor superfamily in multiple sclerosis predisposition

“…[25][26][27] Increased prevalence of HHV6 DNA levels in serum 28,29 and RNA/DNA levels in peripheral blood mononuclear cells 30 have been associated with exacerbations in relapsing-remitting MS. A cellular receptor for HHV6 is the complement regulatory protein CD46; 9 however, as already mentioned, all the molecular players involved in viral entry may not be described yet. Therefore, one of those entry helpers could be encoded by the TNFRSF14 gene and, as shown by the present data, a polymorphism, which was previously associated with rheumatoid arthritis susceptibility has also demonstrated its role in MS predisposition and in HHV6 active replication, as measured by viral DNA levels in serum.…”

“…34 HHV6 variants (A and B) were characterized in the HHV6-positive samples by quantitative PCR, as previously described. 35 In the present study, HHV6 positivity means specific positivity for variant A, which is the one specific for MS. 30 Active HHV6A replication had been searched for in a group of almost 400 healthy controls finding no positive case. Genotyping was blinded for the results of HHV6A DNA levels in serum.…”

Human Herpesvirus 6 Infection as a Trigger of Multiple Sclerosis

“…17 Another 6 studies were classified as A quality but did not reach statistical significance. 18,36,38,39,41,49 Two of those studies did not present any HHV-6-positive patients or controls. 18,49 Four studies were classified as B quality and achieved statistical significance.…”

Mini review article. Human herpesvirus-6 and the etiology of multiple sclerosis: a literature review

“…Mameli et al [39] reported HHV-6 RNA in PBMCs from 1 of 35 patients with MS with active disease and absent in PBMCs from healthy controls. lvarez-Lafuente et al [43] investigated different HHV-6 genes and reported active HHV-6 infection (mRNA) in PBMCs of 16% of patients with MS (32/105 with active disease) and absent in PBMCs from healthy controls. These findings fail to suggest a causative role for HHV-6 DNA in PBLs/PBMCs in the MS disease etiology, but rather that the slightly higher prevalence in patients with MS as compared with that of OND, may be an inability of patients with MS to eliminate initial infection to the same degree as patients with various OND can.…”