Introduction: The therapeutic use of interleukin 1 (IL-1) cytokine receptor antagonists (IL-1RA) has promoted the development of new biological therapies for osteoarthritis (OA). Autologous conditioned serum (ACS) is an alternative, safe and well-tolerated treatment in OA. Sources of data We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL, Embase, SportDiscus, Pedro and Google scholar databases using keywords such as 'interleukin 1', 'osteoarthritis' and 'autologous conditioned serum'.
Areas of agreement: ACS, containing endogenous anti-inflammatory cytokines including IL-1RA and several growth factors, could reduce pain and increase function and mobility in mild to moderate knee OA. AREA OF CONTROVERSY: Given the limited data available on the composition of ACS, the mechanisms through which ACS produces clinical improvement, the duration of its effect and the changes in cytokine levels after repeated injections are still unknown. Growing points Although previous clinical data are encouraging and confirm the safety of this modality, given the limitations of current studies, there should be additional, controlled trials to further confirm efficacy for the use of ACS in OA treatment. AREA TIMELY FOR DEVELOPING RESEARCH: ACS can lead to enhancement of tissue regeneration and to reduction of degenerative mechanisms.