Cerebrospinal fluid lactoperoxidase level is enhanced in idiopathic Parkinson's disease, and correlates with levodopa equivalent daily dose.

Lactoperoxidase (LPO) is proposed to play a role in the pathogenesis of Parkinson's disease (PD). This enzyme has been reported to be enhanced in the cerebrospinal fluid (CSF) in parkinsonian patients. The objective was to look at the relationship of LPO in the CSF and serum with clinical features of idiopathic PD. LPO concentration was analyzed through ELISA techniques. Correlation of CSF or serum LPO and MDS-UPDRS, dopaminergic medication, and other clinical parameters was examined. The findings revealed that LPO concentration in the CSF, not serum, was found to be elevated in patients with PD relative to controls (p < 0.001). CSF LPO concentration negatively correlated with MDS-UPDRS part-IV score (p < .0001), a rating scale that allows evaluating motor complications. CSF LPO level inversely correlated with the dose intensity of the dopaminergic medication regimen, as evaluated with levodopa equivalent dose or LED (mg/day; p < .0001). LED value positively correlated with MDS-UPDRS part-IV score (p < .0001). To sum up, the findings indicate that CSF LPO is found to be elevated in the CSF of PD patients, and this enzyme holds promise as potential biomarker for diagnosis of PD. Increasing the dose intensity of the dopaminergic medication regimen attenuates the elevation in LPO levels in the CSF, and it facilitates the development of motor complications in patients. The pathophysiological mechanisms that seem to be responsible for LPO increase would include dopamine deficiency, oxidative stress, and less likely, microbial infection.