The association between herpes simplex virus type 1 infection and Alzheimer’s disease

Abstract

AbstractBackgroundThere are growing evidences demonstrating the relationship between herpes simplex virus type 1 (HSV‐1) infection and Alzheimer’s disease (AD).MethodWe searched Pubmed, Embase and Cochrane databases for relevant articles. Newcastle‐Ottawa Scale (NOS) was used to evaluate the qualities of these studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random‐effects models. We also performed subgroup analyses stratified by apolipoprotein ε4 (APOE ε4), NOS score and the method of confirming AD.ResultA total of 21 studies between 1990 and 2020 were identified. The pooled OR suggested that HSV‐1 infection is a risk factor of AD: pooled OR 1.40 (95% CI: 1.13‐1.75; I2 = 3%, P = 0.42). In the subgroup analyses, the pooled ORs of HSV‐1 infection associated with AD were 0.75 (95% CI: 0.24‐2.37) among the APOE ε4 positive individuals; 0.85 (95% CI: 0.61‐1.17) among the APOE ε4 negative individuals; 1.51 (95% CI: 1.10‐2.06) in the high NOS score studies; 1.23 (95% CI: 0.85‐1.76) in the moderate NOS score studies; 1.47 (95% CI: 1.16‐1.87) in the clinical diagnosis group, 1.20 (95% CI: 0.77‐1.87) in the autopsy group, respectively.ConclusionOur systematic review and meta‐analysis suggest that HSV‐1 infection is a risk factor of Alzheimer’s Disease.