Correlation between synovial fluid and serum IL-1β levels after ACL surgery–preliminary report

The possibility of controlling the harmful intra-articular influence of elevated interleukin (IL)-1β synovial fluid concentration after anterior cruciate ligament (ACL) surgery could be useful. We investigated the correlation between serum and synovial fluid IL-1β levels following ACL reconstruction. We measured IL-1β concentration periodically in three synovial fluid and four serum samples in each of 20 patients receiving either autologous conditioned serum (ACS) containing endogenous anti-inflammatory cytokines including IL-1Ra and several growth factors (group A) or placebo (group B). A decrease in IL-1β synovial fluid concentration appeared to be more pronounced in absolute terms in group A. In eight patients serum IL-1β was detected on the 6th postoperative day. In four of them whose synovial fluid levels were over 10 pg/ml on the 6th postoperative day, serum IL-1β was detected on the 10th postoperative day. The results were different in group B. Correlation between serum and synovial fluid IL-1β appearance persists in patients after ACL surgery and ACS application. This study is an example of ACS influence on the ACL healing process controlling the IL-1β levels on the basis of the serum IL-1β detection.