Abstract
Growing evidence supports the importance of immune processes in Parkinson's disease (PD). However, there is a need to improve the quality of observational clinical studies investigating the role of immunity in PD. In this context, an expert panel from the COST Action IMMUPARKNET (CA21117) aimed to develop guidance recommendations for conducting optimal immune profiling in PD. Firstly, criteria for inclusion and exclusion of participants, clinical data collection and participant stratification have been considered. Secondly, brain imaging of neuroinflammation has been reviewed. Finally, this review discusses sample collection, handling and storage of biological samples. In conclusion, this document aims to guide the scientific community in the optimal design of immune profiling studies in PD, so that we can generate robust and reliable data to advance our knowledge in this field.