Oxidative damage and cytogenetic analysis in leukocytes of Parkinson's disease patients

Background: Postmortem studies suggest excessive free radical toxicity in the substantia nigra of patients with PD. Increased lipid peroxidation and oxidative DNA damage have been reported in the CNS. Markers of oxidative stress have been identified in the blood of patients with PD. Objective: To assess the presence of spontaneous chromosome and primary or oxidative DNA damage in peripheral blood leukocytes of patients with untreated PD. Methods: Patients with de novo PD (20) and control subjects (16), matched for age, sex, and smoking habits, underwent cytogenetic analysis using the human lymphocyte micronucleus assay coupled with the fluorescence in situ hybridization technique and the Comet assay. Results: Compared with controls, patients with PD showed an increase in the incidence of spontaneous micronuclei (p<0.001); single strand breaks (p<0.001); and oxidized purine bases (p<0.05). Fluorescence in situ hybridization analysis showed micronuclei harboring acentric fragments. Conclusions: There is chromosomal, primary DNA damage and oxidative DNA damage demonstrable in lymphocytes of patients with untreated PD.