Serum pentraxin-3 and systemic inflammatory biomarkers in Parkinson's disease with and without freezing of gait.

OBJECTIVE: Freezing of gait (FOG) is one of the most disabling axial symptoms in Parkinson's disease (PD). Neuroinflammatory mechanisms have been implicated in PD progression, yet the role of systemic inflammatory biomarkers in FOG remains unclear. We investigated the association between serum inflammatory biomarkers and FOG and explored their relationships with clinical measures of motor and freezing severity. METHODS: Thirty PD patients with FOG (FOG +), 31 without FOG (FOG -), and 31 age- and sex-matched healthy controls were enrolled. Serum levels of macrophage inflammatory protein-1 alpha (MIP-1α), MIP-1β, interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and pentraxin-3 (PTX-3) were measured by ELISA. Motor severity was assessed using the Unified Parkinson's Disease Rating Scale, Hoehn-Yahr stage, and the Freezing of Gait Questionnaire. Multivariable logistic regression was performed to evaluate the independent association between PTX-3 and FOG. RESULTS: In unadjusted analyses, serum MIP-1α levels were significantly higher in PD patients than in controls, whereas PTX-3 levels were significantly higher in FOG + than FOG - patients. In the overall PD cohort, PTX-3 correlated positively with UPDRS-II scores (r = 0.364, p = 0.004). Exploratory analyses in the FOG + subgroup showed correlations of MIP-1β and IL-6 with UPDRS-III scores and IL-1β with FOG-Q scores (all p < 0.05). However, PTX-3 was not independently associated with FOG after adjustment for age, sex, disease duration, and levodopa equivalent daily dose. CONCLUSION: Serum PTX-3 showed a preliminary association with FOG in unadjusted analyses, whereas other inflammatory biomarkers demonstrated exploratory associations with motor and freezing-related clinical measures.