Parkinson's disease and Toxoplasma gondii infection: Sero-molecular assess the possible link among patients

We investigated the possible association between Parkinson's disease (PD), the second most common neurodegenerative disorder and Toxoplasma gondii infection, the most common neurotropic protozoan parasitic infection, using serological and molecular techniques. One hundred and fifteen patients with confirmed PD and 115 healthy subjects in the same age and sex distribution were enrolled in this study. Blood samples were taken from each participant and the sera was screened for anti-Toxoplasma antibodies (IgG and IgM). PCR assay was performed in duplicate using the primer pair targeting the B1 gene of Toxoplasma. Amplicons were directly sequenced to conduct the phylogenetic analysis. The prevalence of Toxoplasma infection based on IgG titer was 53% in case and 55.6% in the control groups, revealing no statistically significant association between Toxoplasma seropositivity and PD (OR=0.90; 95% CI=0.54-1.51; P=0.691). According to PCR assay, the prevalence of Toxoplasma infections was 19.3% in the case and 10.4% in control groups which the difference was statistically significant (OR=3.02; 95% CI=1.46-6.27; P=0.002). Multiple sequence alignment of Toxoplasma gondii isolates manifested a common haplotype by the identity: 93.6-100% and divergence: 0-6.7%. We concluded that T. gondii infection not only could not be a risk factor to PD, but even it could be concluded that patients with PD are in more risk to acquisition of infection. These results provide fresh insights into the ambiguous association between T. gondii infection and PD.