ABSTRACT
@#Numerous studies and meta-analyses have been conducted on the role of infectious agents in susceptibility to multiple sclerosis (MS). In this study we aimed to investigate the role of varicella zoster virus (VZV) in susceptibility to MS as an individual participant data (IPD) meta-analysis. After screening and applying eligibility criteria 19 studies were imported for qualitative systematic review and 11 studies were imported for meta-analysis as different subgroups. No significant result was obtained for association of VZV IgG seropositivity with susceptibility to MS. Positive history of VZV infection was significantly associated with susceptibility to MS. Synthesis of IPD showed that presence of VZV DNA was associated with MS(P<0.001) both in peripheral blood mononuclear cells (OR= 22.40 [5.85-85.71]) and in cerebrospinal fluid (OR= 14.42 [5.29-39.29]). In general VZV can be a risk factor for MS; but since VZV infection history is highly prevalent in populations without vaccination and on the other hand MS has low prevalence, this association should not be used as a prognostic or predictive value. The exact mechanism should be investigated in future.