Clinical, biochemical, and histologic effects of intra-articular administration of autologous conditioned serum in horses with experimentally induced osteoarthritis.

This study investigated the effects of an intra-articular administration of autologous conditioned serum (ACS) for treating osteoarthritis in horses. Findings showed improved clinical and histological outcomes, with both lessened lameness and synovial hyperplasia, in horses treated with ACS compared to those receiving a placebo.

Study Design and Methodology

The research involved 16 horses, in which osteoarthritis was surgically induced in one carpal joint. Half of the sample group (8 horses) were treated with ACS, while the other half were administered a placebo solution. Both solutions were injected into the affected joint at recurring intervals—on days 14, 21, 28, and 35.

• Assessments including lameness and synovial fluid analysis were conducted biweekly.
• At the end of the study, necropsy was performed, and gross pathological and histological examinations of cartilage and synovial membrane samples were carried out.

Research Findings

The results revealed no adverse events related to the ACS treatment. The horses that received ACS displayed a substantial clinical improvement in lameness compared to the placebo group. The ACS treatment reduced synovial membrane hyperplasia considerably when compared to the placebo-treated joints.

• While it was not statistically significant, it was also noted that ACS-treated joints appeared to have less cartilage fibrillation and less synovial membrane hemorrhage.
• Synovial fluid concentration of the anti-inflammatory protein interleukin-1 receptor antagonist (assessed via an antibody response) increased following ACS treatment, signifying a positive response.

Conclusions and Future Implications

This controlled study suggests that osteoarthritis-affected joints in horses show significant clinical and histologic improvement following ACS treatment as opposed to placebo treatment. Thus, further controlled clinical trials investigating this treatment are recommended. The study also points towards a need to concurrently explore the underlying mechanisms of action of ACS in treating osteoarthritis.