TNF and Parkinson disease: However, contrary to our prediction in this study, TNF-α level in CSF from the PD-NPSs group was significantly decreased compared with that from the PD-nNPSs group, which might be because that most of the patients included were at the early stage of PD, and the decreased TNF-α implied the potential anti-inflammatory action but not proinflammatory effect on nNPSs at the early stage of PD.