Increased blood-cerebrospinal fluid transfer of albumin in advanced Parkinson's disease

Background: Alterations in blood-brain barrier permeability have been proposed to represent a relevant factor contributing to Parkinson's disease progression. However, few studies have addressed this issue in patients at different stages of disease. Methods: Albumin was measured in cerebrospinal fluid and serum samples obtained from 73 non-demented subjects with idiopathic Parkinson's disease and 47 age-matched control subjects. The albumin ratio (AR) was calculated to assess blood-cerebrospinal fluid and blood-brain barrier function. The group of patients with Parkinson's disease included 46 subjects with Hoehn-Yahr staging between 1 and 2 and 27, with a score ranging from 2.5 to 4. Results: Statistically significant differences in albumin ratio were found between patients with advanced disease, and both early-stage and unaffected groups. Conversely, early-phase patients did not differ from healthy subjects. Additionally, dopaminergic treatment seems to exert a possible effect on AR values. Conclusions: Our study demonstrates that possible dysfunction of the blood-cerebrospinal fluid barrier, blood-brain barrier, or both, characterize Parkinson's disease progression. The associations between clinical scores, treatments and biochemical findings suggest a progressive impairment of barrier integrity during the course of the disease.