title: Effects of repeated intra-articular administration of amikacin on serum amyloid A, total protein and nucleated cell count in synovial fluid from healthy horses.
abstract: BACKGROUND
  Serum amyloid A (SAA) in synovial fluid has recently been used as a marker for septic arthritis in horses but the effects of repeated intra-articular (IA) administration of amikacin on synovial SAA concentrations are unknown.
  
  
  OBJECTIVE
  To report the effect of repeated IA administration of amikacin on SAA, total protein (TP), nucleated cell count (NCC) and differential NCC in synovial fluid of healthy equine joints.
  
  
  METHODS
  A controlled, 2 period crossover study was performed on 5 clinically healthy horses. Each intercarpal joint received one of 2 treatments every 48 h for 5 consecutive times: arthrocentesis alone (control group) or arthrocentesis combined with IA administration of 500 mg of amikacin (treatment group). Clinical and lameness examinations were performed daily. Serum SAA and synovial SAA, TP, NCC and differential NCC were measured and statistically compared. Significance level was set at P < 0.05.
  
  
  RESULTS
  Horses remained healthy and nonlame throughout the study. Baseline values for all variables were not significantly different between groups. Values for TP in the treatment group were significantly higher than in the control group after the first sample (P < 0.05). In both groups NCC increased significantly (P < 0.05) after the first sample. No significant changes were identified in differential NCC. In both groups, all synovial and most serum SAA concentrations remained below the lower limit of quantification.
  
  
  CONCLUSIONS
  Repeated IA administration of amikacin caused increased values of TP and NCC in synovial fluid, with some TP concentrations falling within the range reported for septic arthritis. In contrast, synovial SAA concentrations did not increase in either group.
  
  
  CONCLUSIONS
  Synovial SAA could serve as a more reliable marker than TP and NCC when evaluating a joint previously sampled or treated with amikacin.
authors: Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors: A F
authors: AF
authors: Sanchez Teran
authors: L M
authors: LM
authors: Rubio-Martinez
authors: N F
authors: NF
authors: Villarino
authors: M G
authors: MG
authors: Sanz
mesh_terms: D000583:Amikacin / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D018592:Cross-Over Studies; D005260:Female; D006734:Horse Diseases / Q000139:chemically induced; D006736:Horses; D007270:Injections, Intra-Articular; D007592:Joint Diseases / Q000139:chemically induced / Q000662:veterinary*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D000685:Serum Amyloid A Protein / Q000737:chemistry / Q000378:metabolism*; D013582:Synovial Fluid / Q000737:chemistry* / Q000166:cytology*
chemical_list: D011506:Proteins; D000685:Serum Amyloid A Protein; D000583:Amikacin