41: Changes in plasma cytokine levels are associated with shockwave treatments in horses
The use of extracorporal shock wave therapy (ESWT) for the treatment of muscular-skeletal disorder is of great concern to the horseracing industry. The use of ESWT earlier than 7 days prior to competition is banned by Pennsylvania Racing Commissions because this form of treatment produces a period of sustained analgesia that can be detrimental to the horse if the horse is allowed to compete. However, unlike drugs, ESWT cannot be detected unless associated biomarkers are determined. Little is known about the effect of ESWT on protein expressions including inflammation-associatedcytokines. In this study, we investigated alternative methods to determine if administration of ESWT to the horse had taken place. Eleven thoroughbred horses were treated with shockwave and plasma levels of ten cytokines comprising interleukine (IL) 1 beta (IL-1 β ), IL-1 receptor antagonist (IL-1RA), IL-2, IL-4, IL-6, IL-10, IL-15, interferon gamma (IFN γ ), toll like receptor 2 (TLR2) and tumor necrosis factor alpha (TNF α ) were studied for effect of shockwave. Blood samples were collected prior to ESWT (0, 2, 4, 6, 24, 48, 72, 96-h) and at 2, 4, 6, 24, 48, 72, 96, 168, 336, and 504-h post ESWT. Plasma cytokine concentrations were determined by quantitative enzyme linked immunosorbant assay. Three of ten cytokines showed significant change following ESWT, IL-6 and IL-1 β protein levels were down regulated ( p α protein expression was up-regulated ( p β density might be an effect of the short increase in its antagonist IL-1RA ( p γ and TLR2 did not show significant change although cytokines like IL-4 and IL-10 showed minor change. In addition, baseline level of those cytokines did not show significant change during the days and the week preceding ESWT, indicating that shockwave may trigger inflammatory response by affecting cytokine protein expression in the horse.