Objective: Inflammation of the immune system and the central nervous system has been known as an important predisposing factor for Parkinson’s disease (PD). Increased expression of OX40 protein (CD134) is a known factor for increased inflammation and initiation of NF-kappa-B signaling pathway in different diseases. We aimed to investigate the expression of OX40 at the transcript and serum protein levels. Materials and Methods: Twenty individuals with PD and 20 healthy individuals, as controls, were enrolled in this casecontrol study. Expression of OX40 at the transcript level and serum protein levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assays respectively. Results: The mean expression level of OX40 was increased in patients but not at a significant level (P>0.05). Consistently, the mean serum concentration of OX40 showed a mild, but non-significant, increase in the patients (P>0.05). Conclusion: We conclude that OX40 expression at either the transcript or protein level has no diagnostic utility in asymptomatic PD. This shows the need for clinical, cellular and interventional research to detect new robust biomarkers.
