Peripheral immune correlates of childhood and adolescent peer relationships: A systematic review

The objective of this review was to comprehensively evaluate the literature investigating associations between peripheral immune correlates and youth peer relationship dimensions. We aimed to identify potential aspects of peer relationships in childhood and adolescence that may be associated with immune profiles and to identify gaps in the field to provide suggestions for future research in this area. We conducted a systematic electronic search in health-related databases from the earliest records to December 2020. Search terms included domains related to youth, immune correlates, and peers. We summarized studies by the time between the peer measurement and the immune outcome. In the 17 included studies, associations between peer dimensions and immune outcomes varied substantially. Peer victimization in youth demonstrated the most consistent negative associations with immune health across development, including within 1 week of measurement, 1-3 years later, and 10 or more years later. This review indicated that that peer relationships during youth may have important associations with immune processes; however, there are several gaps in the literature regarding the operationalization of peer relationships, the timing of the immune measurement, and the type of immune outcome to be addressed by future research.