Our findings highlight a dysregulated autoantibody network targeting the RAS in PD, characterized by increased levels of pro-oxidative/pro-inflammatory AT1-AAs and ACE2-AAs and protective anti-oxidative/anti-inflammatory MasR-AAs, along with altered correlations among RAS-AAs and cytokines and oxidative stress markers such as 27-OHC. Here, AGTR1 is linked to Parkinson disease.