Genetic causal relationship between multiple immune cell phenotypes and Parkinson's disease: a two sample bidirectional Mendelian randomization study

BACKGROUND: The exact etiology of Parkinson's disease (PD), a degenerative disease of the central nervous system, is unclear. It is currently believed that its main pathological basis is a decrease in dopamine concentration in the striatum of the brain. Although many researchers have previously focused on the critical role of the immune response in PD, there has been a lack of valid genetic evidence for a causal association between specific immune cell traits and phenotypes and PD. METHODS: We employed Mendelian randomisation (MR) as an analytical method to effectively assess genetic associations between exposure and outcome. Based on the largest genome-wide association study (GWAS) data to date, causal associations between multiple immune cell phenotypes and PD were validly assessed by using single nucleotide polymorphisms (SNPs), which are randomly assigned and not subject to any causality. RESULTS: By testing 731 immune cell phenotypes and their association with PD, the results of IVW analysis suggested that some phenotypes were considered to have a causal effect on PD(P＜0.05) . In addition, PD could have an effect on certain immunophenotypes located on Myeloid cell panel, Monocyte panel, the specific immunophenotypic results and statistical analysis values are shown in the text. The results of sensitivity analyses suggested that none of them observed the presence of horizontal pleiotropy. CONCLUSION: Our study identified a close link between immune cells and PD, and the results of this study provide ideas for the study of the immune mechanism of PD and the exploration of effective therapeutic means.