Autologous conditioned serum in equine and human orthopedic therapy: A systematic review

This systematic review aims to compile and present information of studies evaluating the effectiveness of autologous conditioned serum (ACS) in the healing of tendon, ligament and articular lesions in humans and horses. A systematic search of articles using Medline, PubMed, Embase, Bireme and Google Scholar was conducted up to August 2020. Studies regarding ACS' use in human orthopedic lesions were included if classified as RCTs, cohort and case-controls. All studies regarding this therapy in equine medicine were included given their scarcity. Pre-clinical experimental studies were selected if controlled. A total of 1474 results were found; 126 articles were fully accessed, and 28 studies met the inclusion criteria. In vitro studies failed to demonstrate consistent positive properties and effects, while most clinical trials and observational studies indicated a beneficial response associated with ACS administration. However, RTCs and observational studies presented together mostly an unclear to high risk of bias, with only a few being considered of low risk. In face of the observed inconsistencies, the use of ACS in the treatment of musculoskeletal lesions, although safe, promising and appealing, still cannot be recommended without due caution. Overcoming these incongruences will demand efforts to construct well-designed studies and to regard ACS as an autologous product that encompass a diverse composition.