Lymphocyte proteomics of Parkinson's disease patients reveals cytoskeletal protein dysregulation and oxidative stress

AIMS: There is increasing evidence of biochemical alterations in peripheral blood lymphocytes of Parkinson's disease (PD) patients. In this work, we describe the changes in protein levels in peripheral lymphocytes of PD patients in order to identify potential peripheral biomarkers. MATERIALS & METHODS: By means of 2D electrophoresis and mass spectrometry protein identification, we compared patients under L-3,4-dihydroxyphenylalanine (L-DOPA) treatment, patients under subthalamic nucleus deep-brain stimulation and healthy controls. RESULTS: Statistical analysis of the results demonstrated that cofilin-1, tropomyosin, and a specific actin isoform vary significantly in patients, regardless of the therapy. Two different isoforms of gamma-fibrinogen either correlate with the disease state or with the disease duration. Eventually, specific changes associated with the different therapies allowed to highlight oxidative stress conditions in lymphocytes in patients treated with higher doses of L-DOPA. CONCLUSIONS: As a whole, peripheral blood lymphocytes are sensitive reporters of PD over inter-individual variability, and allow the identification of specific alterations that could be further exploited for diagnostic purposes.