Systemic Endotoxemia, Inflammatory Activation, and Lipid Dysregulation in Parkinson's Disease: Evidence from Circulating LPS-Related Biomarkers and Plasma Lipids.

Growing evidence implicates neuroinflammation, gut-derived endotoxemia, and dysregulated lipid metabolism in the pathogenesis of Parkinson's disease (PD). However, the relationships among circulating lipopolysaccharide (LPS), LPS-handling proteins, systemic inflammatory activation, and lipid fractions remain insufficiently characterized. The aim of this study was to compare LPS levels, LPS-related inflammatory mediators, and plasma lipid parameters between PD patients and matched controls, and to explore correlations among these biomarkers. Twenty PD patients and twenty matched controls underwent fasting venous sampling. Circulating LPS, lipopolysaccharide binding protein (LBP), soluble cluster of differentiation 14 (sCD14), high-sensitivity C-reactive protein (hsCRP), and phospholipid transfer protein (PLTP) were quantified via LAL assay and ELISAs. Serum cholesterol, HDL cholesterol (HDL-C), phospholipids (PLs), HDL-PLs and triacylglycerols (TAGs) were assessed using validated biochemical techniques. LPS concentrations did not differ between groups. However, PD patients showed elevated sCD14 and hsCRP levels, reduced LBP, and increased PLTP. Lipid profiling revealed lower total cholesterol and reduced HDL-associated cholesterol and phospholipids in PD, while TAG levels remained unchanged. Correlation analyses indicated coordinated associations between inflammatory markers and lipid fractions, with distinct interaction patterns in PD compared with controls. These findings support a mechanistic interplay among endotoxemia, innate immune activation, and lipid dysregulation in the pathophysiology of PD.