Early effects of anti-TNFα antibodies in horses with osteoarthritis

Osteoarthritis (OA) is the most common pathology in sport horses, presenting a chronic and recurrent course. Traditional anti-inflammatory treatments provide only temporary clinical improvement and pain relief; however, they have been associated with metabolic disorders in articular cartilage in the medium term. In this study, we generated a llama polyclonal antibody against equine TNF-α, which was used for intra-articular treatment in horses with OA. Treatment effects were assessed through clinical examination and the determination of inflammatory parameters (MMP-2, MMP-9, LDH, and GAGs) in synovial fluid prior to treatment (T0) and on day 30 (T30). Treated animals showed significant improvement in the clinical score, which decreased from 8.47 ± 2.57 to 6.16 ± 1.71 (mean ± SD) on T30 (p < 0.001). Additionally, a reduction in the activity of MMP-2 (188 % ± 82.99 to 147 % ± 40.6 %, p < 0.05), MMP-9 (100 % ± 61.28 to 74.37 % ± 64.26, p < 0.05), and LDH (239.3 IU/l ± 147.4 to 143 IU/l ± 61.21, p < 0.01) was observed. Furthermore, on T30, GAGs levels were significantly increased (1.167 ± 0.46 mg/ml to 1.439 ± 0.267 mg/ml, p < 0.01). These results indicate that the local blockade of pro-inflammatory molecules such as TNF-α reduces pain and the levels of inflammatory molecules associated with catabolic processes and joint damage.