What is IRAP Therapy for Horses?

By Dr. Jennifer Wickline, DVM

A relatively new therapy in the management of equine arthritis is IRAP Therapy. Horse owners today have very little knowledge about IRAP and even less of an understanding of that this medical treatment is all about.

IRAP Therapy is Interleukin-1 Receptor Antagonist Protein, also known generically as autologous conditioned serum (ACS).When a horse has arthritis or suffers an injury, inflammation is rampant within the affected joint, and the inflammation itself begins to become the problem by degrading surrounding tissues such as joint cartilage. The IRAP protein stops the action of Interleukin-1 and thus stops the inflammatory cascade that send our athletic horses in to a no show, non-productive stage due to the degenerative joint problems that are created as a result. One common misconception about IRAP is that it regenerates tissue ­ this is the job of stem cells, and even though IRAP is often grouped with stem cells in the regenerative medicine category, it is more like a ‘self-protecting agent’ ­ it simply amplifies protective proteins already made by the body.

The process by which it is harvested is simple. Approximately 60 milliliters of blood is carefully taken from the jugular vein of the patient in a special syringe with coated glass beads inside. This syringe is then put in an incubator for 24 of more hours to allow IRAP production. The coating on the glass beads inside the syringe intensifies this process and allows the IRAP concentration to multiply to a high degree within the sample. After incubation, the sample is put in a centrifuge and spun down so that the serum with IRAP concentrated in it can be separated. The serum is passed through a filter, and is then ready to be injected into the affected joint.

Fortunately, one sample often yields 4-6 doses of IRAP, and the standard treatment protocol is one dose (injection) per week for 4 weeks. Any remaining doses can be stored in the clinic freezer and be used at a later date. The length of efficacy for IRAP has not been determined in the scientific literature, but anecdotal data suggests some horses may need retreatment every 6 months, while some horses go for years without the need for another treatment. There are many ideal situations for its use ­ such as a young performance horse that is showing signs of soreness in a joint, or any age horse that incurs a joint injury. These are limited examples, and many additional scenarios exist.

Come visit us at Equine Veterinary Services and let us assist you in assessing whether IRAP therapy may be indicated for your horse.