Increased cartilage oligomeric matrix protein concentrations in equine digital flexor tendon sheath synovial fluid predicts intrathecal tendon damage.

OBJECTIVES: To evaluate digital flexor tendon sheath (DFTS) synovial fluid cartilage oligomeric matrix protein (COMP) concentrations as a molecular marker for intrathecal pathology. STUDY DESIGN: Case control study. ANIMALS: Horses (n=46) with DFTS tenosynovitis; 23 fresh cadaver horses. METHODS: DFTS synovial fluid samples were collected from clinical cases with noninfected DFTS tenosynovitis and from control DFTS. Clinical and surgical findings were recorded, and dissection of control limbs was performed to confirm the DFTS to be grossly normal. Synovial fluid COMP was quantified using a homologous competitive inhibition ELISA. RESULTS: Abnormalities were identified tenoscopically: intrathecal tendon/ligament tearing was identified in 37 cases and 9 had other lesions. In control horses, synovial fluid COMP was higher in younger horses. Clinical cases with intrathecal tendon/ligament tearing had higher synovial fluid COMP than either clinical cases with other lesions, or controls. In horses ≥5 years old, the sensitivity and specificity of the assay was high for diagnosing intrathecal tendon/ligament tearing. CONCLUSIONS: COMP concentrations in DFTS synovial fluid were significantly greater than those in normal horses with noninfected tenosynovitis caused by intrathecal tendon/ligament tearing, but not by other lesions.

A preliminary study on the effect of wounding on transforming growth factor-ß1 and cartilage oligomeric matrix protein concentrations in the skin of horses.

OBJECTIVE: To evaluate whether wound type or site influence the production of cartilage oligomeric matrix protein (COMP) and transforming growth factor ß1 (TGF-ß1), and determine if there is a correlation between TGF-ß1and COMP during healing. STUDY DESIGN: Experimental. ANIMALS: Standardbred horses (n=6), 4-8 years old. METHODS: Six, standardized, full-thickness skin wounds (open, straight, and elliptical) were surgically created on the neck (n=3) and metacarpus (3) on each horse. Wounds were randomly allocated to site and side. Tissue samples were collected before creating wounds and on days 7, 14, and 42. COMP concentration (µg/g dry weight of tissue) was determined using a standard competitive ELISA and TGF-ß1 (ng/g dry weight of tissue) was determined using a commercially available sandwich ELISA. RESULTS: COMP concentrations were higher in intact skin on the neck compared with the metacarpus (P=.02). There was no difference in COMP and TGF-ß1 concentrations between the different wound types or sites during healing. There was no correlation between TGF-ß1 and COMP during healing. CONCLUSIONS: Within the limitations of the study design, production of COMP during healing of skin wounds does not appear to be influenced by wound type or anatomic site, nor does it appear to be correlated with TGF-ß1 concentrations.