Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
Veterinary Population Medicine
Non Technical Summary
Autologous conditioned serum (ACS), more commonly known in the equine industry by the tradename "IRAP", is a novel treatment for joint inflammation in horses. Inflammation that is associated with osteoarthritis leads to pain during exercise, which manifests to the rider as lameness. A common end result is decreased performance and athletic potential. IRAP is a derivative of blood collected from the same horse that receives the IRAP treatment. Monocytes are cells normally circulating within blood that can produce anti-inflammatory proteins when exposed to certain surfaces, such as borosilicate beads. The beads are mixed with blood in a warm environment for 24 hours and then the blood is spun to separate out serum that contains various anti-inflammatory proteins. The main anti-inflammatory protein that is upregulated in IRAP is called 'interleukin-1 receptor antagonist protein (IL-1ra)'. Potentially, altered levels of various other proteins and enzymes that regulate inflammation (such as cytokines, growth factors, matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases-TIMPs) may occur. Once IRAP has been prepared in this fashion, several consecutive doses (over the course of weeks) are injected directly into an arthritic joint. Our fundamental (and seperately funded) project is to measure the concentration of cytokines, growth factors and matrix metalloproteinases present in the IRAP product and in joint fluid of osteoarthritic coffin joints. Blood and joint fluid will be sampled from 12 horses diagnosed with coffin joint osteoarthritis that are subsequently treated with IRAP therapy using a routine treatment regime (1 dose every 7 days for 3 total doses). The goals of proposed funding herein is to build upon our initial investigation by evaluating a fourth family of anti-inflammatory proteins, known as 'tissue inhibitors of matrix metalloproteinases (TIMP -1, -2, -3, -4)'. This family is responsible for regulating joint destruction created by matrix metalloproteinases. Concentrations of TIMPs in the IRAP product itself, as well as in joint fluid collected following administration of IRAP, will be determined using technology that allows for concurrent measurement of several proteins (in this case TIMP -1, -2, -3, -4) in a single small sample of serum or joint fluid. We anticipate that there will be an increase in TIMP proteins within the IRAP product compared to control serum. We also anticipate that following administeration of IRAP into osteoarthritic joints, we will see an increase in the concentration of TIMP proteins in the joint fluid compared to original joint fluid sampled prior to IRAP therapy. This would indicate that TIMP proteins are an active participant in the IRAP product and help reduce inflammation present in osteoarthritic joints by regulating the joint destruction caused by matrix metalloproteinases. This knowledge would help to guide future IRAP studies, and help provide further scientific evidence supporting the use of this therapeutic in management of lameness in horses.
Animal Health Component
30%
Research Effort Categories
Basic
70%
Applied
30%
Developmental
0%
Goals / Objectives
Osteoarthritis (OA) is a debilitating disease affecting the athletic performance of horses. Lameness, the symptomatic manifestation of OA, has been described as the most important concern for horse owners, and carries significant economic cost to the equine industry10,11. In an attempt to minimize the effects of lameness, treatments with various medications or biologics have been used. Autologous conditioned serum (ACS), more commonly known as "IRAP", is one novel treatment for lameness attributable to OA that is commonly used by equine veterinarians12. Although many equine veterinarians claim a significant improvement in lameness following joint injection with IRAP, very limited scientific research is available supporting this novel therapy. IRAP is a product derived from the blood of the same horse. Blood is collected from the jugular vein in the neck in a special syringe that contains borosilicate beads. These beads, when combined with blood and then kept warm in an incubator for 24 hours, act to stimulate increased concentrations of anti-inflammatory proteins that normally circulate within the horse's body. The IRAP product that results is then injected into the osteoarthritic joint. Previous studies have shown that one main anti-inflammatory product, called 'interleukin-1 receptor antagonist protein' (IL-1ra), is elevated within the product. It is presumed that the increased levels of IL-1ra (as found within the IRAP product) competitively binds pro-inflammatory receptors and thus decreases progression of inflammation. However, it is highly likely that other proteins (both good and bad) within the blood are increased following both processing and administration of IRAP into the joint. Limited understanding exists as to which specific proteins, beyond IL-1ra, may be present within the product contributing to the improvement in lameness. As well, it is unknown how much the product varies in composition between individual horses. The rationale for this proposal is that in spite of the common clinical usage of IRAP for treatment of lameness in sport horse practice, little is known about the actual composition of the product injected into the horse and how much it varies from horse to horse. Likewise, little is known about the specific changes in pro- and anti-inflammatory factors within the joint after treatment. This lack of knowledge about the specifics of IRAP and the response it causes in the joint points out an urgent need for more scientific rationale and guidelines for the clinical use of IRAP. Knowledge gained from this study will help guide equine veterinarians so that they can make more informed decisions regarding the potential benefits and limitations of IRAP therapy in the horse. The goals of proposed funding herein is to build upon our initial investigation by evaluating a fourth family of anti-inflammatory proteins, known as 'tissue inhibitors of matrix metalloproteinases (TIMP -1, -2, -3, -4)'. This family is responsible for regulating joint destruction created by matrix metalloproteinases. Concentrations of TIMPs in the IRAP product itself, as well as in joint fluid collected following administration of IRAP, will be determined using technology that allows for concurrent measurement of several proteins (in this case TIMP -1, -2, -3, -4) in a single small sample of serum or joint fluid.
Project Methods
Separate grants to other funding agencies have been submitted by the investigators outling a study that will collect serum and synovial fluid samples from 12 horses with distal inter-phalangeal joint osteoarthritis that are subsequently treated with ACS therapy. Within these proposals, collected serum and synovial fluid samples will be analyzed for changes in concentration of various cytokines, growth factors and matrix metalloproteinases that are active during inflammation. Analysis of samples will be achieved using a novel multi-plexing assay technology that allows multiple biomarkers to be measured from a single serum or synovial fluid sample. The current proposal requests funding only for the measurement of the tissue inhibitor of matrix metalloproteinases family (which are not being assessed in the other study). The specific aims of this study are to measure: (1) tissue inhibitors of matrix metalloproteinases (-1, -2, -3, -4) concentrations in equine ACS and (2) evaluate ACS effects on tissue inhibitors of matrix metalloproteinases in synovial fluid 7 days, 14 days, and 21 days after intra-articular administration. We hypothesize that there will be an increase concentration of the anti-inflammatory tissue inhibitors of matrix metalloproteinases within the ACS product compared to control serum. We also hypothesize that we will see an increase in tissue inhibitors of matrix metalloproteinases in synovial fluid, and that these changes will be in greater proportion than the changes seen in (previously measured) pro-inflammatory cytokines and matrix metalloproteinases.