Ann Neurol: Lower lymphocyte counts are associated with an increased risk of Parkinson's disease

Compared to the controls, there were differences in immune function biomarkers (including white blood cell difference counts) in patients with Parkinson's disease (PD).
these differences may be clinically significant biomarkers in predicting PD and clarifying its pathogenesis.
, a study published recently in The Annals of Neurology, an authoritative journal in the field of neurology, aims to determine whether the external immune disorder is associated with an increased risk of subsequent PD diagnosis.
researchers assessed the relationship between PD occurrence and baseline white blood cell counts and other blood markers of acute inflammation through a longitudinal queue of more than half a million participants in the UK biolibrary.
researchers used a series of sensitivity analyses and Mendel Randomization (MR) to further explore the nature of the association.
the study retained 465 PD cases and 312,125 controls after excluding patients with combined disorders that could affect inflammatory biomarkers.
lower lymphocyte count was associated with an increased risk of subsequent PD diagnosis (the ratio ratio of lymphocyte count to 1.18 per SD reduction, 95% CI to 1.07-1.32, adjusted P=0.01).
there is evidence that decreased eosinophils, monocyte counts, and CRP are associated with increased PD risk, and increased neutral granulocyte counts are associated with increased PD risk.
sensitivity analysis, only the association between lower lymphocyte counts and increased PD risk remained robust.
MR suggests that the effect of reducing lymphocyte counts on PD risk may be causal (1 SD for each reduction in lymphocyte count; 1.09 for OR, 1.01-1.18 for 95% CI, p=0.02).
result, a decrease in lymphocyte counts was associated with an increased risk of subsequent PD.