Plasma IL-24 is associated with time to first fall in Parkinson's disease.

Plasma inflammatory protein biomarkers associated with clinical milestone heterogeneity in Parkinson's disease (PD) remain undefined. We measured 92 inflammation-related plasma proteins in 82 PD patients using the Olink Proximity Extension Assay. No proteins differed significantly between fallers and non-fallers. However, among fallers, plasma interleukin-24 showed the strongest correlation with observed time to first fall (unadjusted r = 0.752, q = 0.071), and this signal was also observed in an exploratory covariate-adjusted model (q = 0.030). Colony-stimulating factor 1 showed a comparable but non-significant correlation. In group comparisons for symptomatic orthostatic hypotension, CCL11 differed significantly between patients with and without symptomatic orthostatic hypotension (q = 0.0004). These exploratory findings highlight candidate inflammatory protein profiles related to milestone heterogeneity in PD, warranting validation in longitudinal cohorts.