Cartilage-derived biomarkers and lipid mediators of inflammation in horses with osteochondritis dissecans of the distal intermediate ridge of the tibia.
OBJECTIVE
To assess whether reported alterations in metabolism of cartilage matrix in young (0 to 24 months old) horses with osteochondritis dissecans (OCD) may also be found in older (24 to 48 months old) horses with clinical signs of OCD and to investigate the role of eicosanoids in initiating these clinical signs.


METHODS
Synovial fluid was collected from 38 tarsocrural joints of 24 warmblood horses with (22 joints of 16 horses) or without (16 joints of 8 horses) clinical signs and a radiographic diagnosis of OCD of the distal intermediate ridge of the tibia.


METHODS
Turnover of type II collagen was investigated by use of specific immunoassays for synthesis (carboxypropeptide of type II collagen [CPII]) and degradation (collagenase-cleaved fragments of type II collagen [C2C]) products. Furthermore, glycosaminoglycan (GAG), leukotriene (LT) B(4), cysteinyl LTs, and prostaglandin (PG) E(2) concentrations were determined, and concentrations in joints with OCD were compared with those in joints without OCD.


RESULTS
Concentrations of CPII, C2C, and GAG did not differ significantly between affected and nonaffected joints. Fluid from joints with OCD had significantly higher LTB(4) and PGE(2) concentrations than did fluids from nonaffected joints.


CONCLUSIONS
Altered collagen or proteoglycan turnover was not detected in 24- to 48-month-old horses at the time they developed clinical signs of OCD of the distal intermediate ridge of the tibia. However, increased concentrations of LTB(4) and PGE(2) in fluid of joints with OCD implicate these mediators in the initiation of clinical signs of OCD.
de Grauw
Janny C
JC
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, CM, the Netherlands.
Brama
Pieter A
PA
Wiemer
Peter
P
Brommer
Harold
H
van de Lest
Chris H
CH
van Weeren
P Rene
PR
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002356:Cartilage / Q000378:metabolism*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D007249:Inflammation / Q000378:metabolism; D050356:Lipid Metabolism / Q000502:physiology*; D010008:Osteochondritis Dissecans / Q000378:metabolism / Q000662:veterinary*; D013977:Tibia / Q000378:metabolism / Q000473:pathology*
D015415:Biomarkers