Interleukin-1 Receptor Antagonist Protein, IRAP, is an autologous conditioned serum used by veterinarians to manipulate the body’s biological mechanisms to treat joint disease or degenerative joint disease. Molecular biology has identified the major inducer of osteoarthritis being a general inflammatory cytokine interleukin-1 (IL-1) which plays a key role in accelerating tissue destruction and the repair mechanisms.

Osteoarthritis is a common musculoskeletal cause of lameness in a horse. Clinical signs can include joint swelling from cartilage damage or inflammation of the joint lining or synovitis. The traumatized joint can release IL-1 and IRAP helps to block this protein from producing additional damage. In a healthy joint, IL-1 and interleukin-1 receptor antagonist (IL-1Ra) are in balanced concentrations. In cases of osteoarthritis, there is not sufficient IL-1Ra produced to block the destructive effects of the increased IL-1. The result is inflammation, joint pain, and eventually cartilage destruction.

The IRAP process includes drawing blood into a 60 ml syringe which contain glass beads. The glass beads attract and bind monocytes (a type of white blood cell). The cells are then stimulated to produce regenerative and anti-inflammatory proteins without the addition of drugs. This process takes place over an incubation period of 24 hours. Once incubation is complete, centrifugation is performed to remove the red blood cells. The remaining serum is split into individual doses. Joint injections are then completed every other week for three treatments and a remaining dose or two remain frozen at -20F for future treatments

A few products are on the market including IRAP, IRAP II, and Pro-Stride. Research has compared IRAP and IRAP II and concluded that IRAP II has a modestly improved cytokine profile but both products produced a significant increase in IL-1Ra. We are happy to provide IRAP II at our veterinary practice.