Osteoarthritis is a degenerative disease that affects joint cartilage and bones and leads to arthritis within the joint. In a recent study, researchers at the Colorado State University (CSU) Equine Orthopaedic Research Center (EORC) examined the effects of a new product called autologous conditioned serum (ACS) to stimulate the production of interleukin-1 receptor antagonist (IL-1Ra or IRAP), which blocks interleukin-1 proteins that are associated with joint inflammation and accelerate the deterioration of tissue. Previous studies have shown IL-1Ra blocks excessive production of synovial fluid in joints, which causes joint swelling or enlargement.

David Frisbie, DVM, PhD, Dipl. ACVS, of CSU’s EORC, said the ACS system uses glass beads exposed to chromium sulfate to stimulate peripheral white blood cells within the joint to produce an "anti-inflammatory soup."

Researchers used 16 horses with osteoarthritis. Half of the horses received intra-articular (into the joint) ACS injections on Days 14, 21, 28, and 35; the other group (the control) received intra-articular saline injections at the same intervals. Both groups began a rigorous work schedule (five days a week), which they continued for the remainder of the study. Horses were evaluated each week using the AAEP lameness grading scale (1 to 5; 5 being the worst).

"Horses treated with ACS were observed to have significantly improved lameness in osteoarthritis joints at the end of the study weeks after the last treatment compared with placebo-treated horses," Frisbie said. Horses treated with ACS averaged a lameness grade of 1.3, while horses treated with the placebo were about a grade 2.1