Prevalence and relevance of antibodies to type-I and -II collagen in synovial fluid of dogs with cranial cruciate ligament damage.
OBJECTIVE
To measure and compare synovial fluid antibody titers to type-I and -II collagen in stifle joints with instability caused by complete or partial cranial cruciate ligament (CCL) rupture and joints with osteoarthrosis secondary to other pathologic changes in dogs.


METHODS
82 dogs with diseased stifle joints.


METHODS
Synovial fluid samples were collected from 7 dogs with clinically normal stifles (control group) and 82 dogs with diseased joints (50 stifle joints with complete rupture of the CCL, 20 with partial damage of the CCL, and 12 joints with radiographic signs of osteoarthritis secondary to other arthropathies). Synovial fluid samples were tested for autoantibodies to type-I and -II collagen by an ELISA.


RESULTS
In dogs with complete and partial CCL rupture, synovial fluid antibody titers to type-I and -II collagen were significantly increased, compared with control dogs. Forty-eight percent (24/50) of samples from dogs with complete CCL rupture and 35% (7/20) of samples from dogs with partial CCL rupture had antibody titers to type-I collagen that were greater than the mean plus 2 standard deviations of the control group titers. Synovial fluid antibody titers to type-II collagen were high in 40% of the dogs with partial or (8/20) complete (20/50) CCL rupture. Dogs with osteoarthrosis secondary to other pathologic changes had significantly increased synovial fluid antibodies to type-I and -II collagen, compared with control dogs.


CONCLUSIONS
Increases in autoantibodies to collagen in synovial fluid are not specific for the type of joint disorder. It is unlikely that the anticollagen antibodies play an active role in the initiation of weakening of the CCL.
de Rooster
H
H
Department of Diagnostic Imaging of Domestic Animals, Faculty of Veterinary Medicine, University of Ghent, Merelbeke, Belgium.
Cox
E
E
van Bree
H
H
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000276:immunology*; D000070598:Anterior Cruciate Ligament Injuries; D001323:Autoantibodies / Q000032:analysis*; D003094:Collagen / Q000276:immunology*; D004283:Dog Diseases / Q000276:immunology; D004285:Dogs / Q000293:injuries*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D007592:Joint Diseases / Q000276:immunology / Q000662:veterinary; D010003:Osteoarthritis / Q000276:immunology / Q000662:veterinary; D015995:Prevalence; D012422:Rupture, Spontaneous / Q000662:veterinary; D013264:Stifle / Q000276:immunology / Q000293:injuries; D013582:Synovial Fluid / Q000276:immunology*
D001323:Autoantibodies; D003094:Collagen