IRAP

Autologous conditioned serum (ACS), also known as "IRAP" (IL-Ra or interleukin-1 receptor antagonist protein), is gaining more popularity as a local joint treatment strategy for horses.

The exploration of IRAP as a treatment for synovitis, osteoarthritis and rheumatoid
arthritis began shortly after its first published characterization in 1984. The
ability of this molecule to act as both a symptom- and disease-modifying
agent in various species (including horses and humans) has prompted its
clinical application as a treatment for joint disease. The goal behind
IRAP treatment is to use the body's own inflammation-fighting cells to reduce
arthritis rather than the synthetically-produced antiinflammatory
medications that we buy in a bottle. Because antiinflammatory cells are
produced by the host body itself, we can often expect an improved degree
of response as well as a longer duration of response. IRAP works by blocking the destructive effects of interleukin-1, which is a major mediator of joint inflammation and disease.

The first scientific publication highlighting the benefits of IRAP appeared in 2003. Recently, however, a newer "version" of IRAP has become available. This product has been cleverly named "IRAP II".

Both IRAP products are prepared from the horse's blood, which is incubated for a period of 24 hours in the presence of glass beads that stimulate production of IL-1Ra. Conditioned serum is subsequently recovered and injected back into the arthritic joint(s) to reduce inflammation and improve comfort.

A study comparing the two products was recently presented by David Frisbie, DVM, PhD, Dipl. ACVS at the 2010 AAEP Convention in Baltimore, MD. Dr. Frisbie and colleagues examined the composition of serum prepared using both IRAP I and IRAP II products. Both products yielded increased levels of IL-1Ra and insulin-like growth factor as compared with untreated serum. IRAP II, however, yielded more than twice the amount of IL-1Ra, which theoretically would magnify its beneficial effects. The study also showed that using IRAP II resulted in lower local production of other inflammatory mediators (such as tumor necrosis factor-α) as compared to IRAP I.

Learn more about IRAP and other JOINT THERAPIES in our CLIENT EDUCATION LIBRARY.