New Lameness Treatments: IRAP™ Therapy

One of several new high-tech treatments for equine lameness is the creation of an enriched serum injection for horses with potential joint damage. "IRAP" is not a new hip-hop group; it's a therapy that has quickly made its own place at the table of equine therapy, especially for sport horses and racehorses whose owners expect a return to the previous level of soundness and performance...in the shortest possible length of time.

Interleukin-1 Receptor Antagonist Protein (IRAP™) therapy works like this: the veterinarian, often a surgeon or lameness specialist, injects a horse’s affected joint with serum that contains anti-inflammatory proteins that block the harmful effects of Interleukin-1 (IL-1), an inflammatory cytokine that has been shown to accelerate destruction of cartilage during osteoarthritis. (A cytokine is a chemical secreted by the immune system to attack infections and damaged or dying cells.)

What makes the process a little complicated is that Interleukin-1 (IL-1) is a quite normal part of the horse's inflammatory response but it can sometimes be detrimental to a horse's joints and accelerate damage to cartilage there. IRAP™ creates a barrier that prevents IL-1 from having its damaging effect.

Since the serum sample is derived from the horse’s own blood, there is minimal risk of an adverse reaction. The incubated serum also does not contain any drugs.

The treatment process consists of drawing a blood sample using a special syringe containing glass beads. The blood is incubated for 24 hours and a centrifuge separates the serum from the red blood cells. The serum, now enriched with Interleukin-1 receptor antagonist protein, is divided into three or four doses. The horse receives one dose injected into the affected joint once weekly for three to five weeks.

A quick check around the web found that quite a few vet clinics are promoting IRAP therapy. Here are some comments from veterinarians:

Dr. Laura Werner of The Equine Center in San Luis Obispo, California: "The reason IRAP is so exciting is its potential for a long-term effect on battling osteoarthritis. Whereas some of the therapies might only have short-term effect, IRAP has the potential to stop the cartilage matrix from being degraded and increase healing. IRAP has the ability to stop the inflammation cycle and bring comfort to your horse. The research on IRAP is ongoing but the results have been very encouraging."

Dr. Laurie Tyrrell of Virginia Equine Imaging: "IRAP can also be used as maintenance therapy throughout a competition season to reduce the amount of steroid use. IRAP therapy is not for every horse. There are some factors that make a horse a less successful candidate; however the therapy shows great promise for horses that have become refractory to traditional management of osteoarthritis, as well as offering an alternative therapy for those worried about excessive use of corticosteroids."

According to the web site of Steinbeck Country Equine Clinic in Salinas, California: "Coffin joints and stifles that don’t respond well to steroid injections seem to be the most popular condition to treat (with IRAP therapy). Reactions are uncommon largely due to the fact that it is the patient’s own serum."

IRAP is one of the many therapies and treatments that will be on the program of the 4th International Equine Conference on Laminitis and Diseases of the Foot to be held in West Palm Beach, Florida, from November 2-4.