title: Serum concentrations of the third component of complement in healthy dogs and dogs with protein-losing nephropathy.
abstract: OBJECTIVE
  To develop a method for determining the concentration of the third component of complement (C3) in canine serum, to establish a reference range for C3 in healthy dogs, and to evaluate dogs with protein-losing nephropathy (PLN) to determine whether PLN is associated with decreased serum C3 concentrations.
  
  
  METHODS
  30 healthy dogs and 49 dogs with PLN.
  
  
  METHODS
  Serum samples were obtained from healthy dogs at the time of examination, whereas serum samples were obtained from dogs with PLN at the time of diagnosis. All samples were frozen at -70 degrees C until analyzed. Serum C3 concentrations were determined by use of a sandwich ELISA. Concentrations were expressed as the number of dilutions in which C3 could be detected.
  
  
  RESULTS
  C3 was detectable in healthy control dogs (range, 1,920,000 to 15,400,000 dilutions; median, 9,600,000 dilutions). This represented a range of four 2-fold serum dilutions. In addition, C3 was detectable in dogs with PLN (range, 1,460,000 to 30,070,000 dilutions; median, 7,680,000 dilutions), which represented a range of six 2-fold serum dilutions. There was no significant difference in C3 concentrations between the 2 groups.
  
  
  CONCLUSIONS
  C3 is a critical part of the immune defense system that has not been extensively examined in veterinary medicine. An ELISA was developed for measuring C3 concentrations, and a reference range for healthy dogs was established. Significant decreases in C3 concentrations were not detected in any dog with PLN. Additional studies will be required to definitively determine the importance of serum C3 concentrations in PLN.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, 70803, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Acierno
authors.forename: Mary Anna
authors.initials: MA
authors.lastname: Labato
authors.forename: Leah C
authors.initials: LC
authors.lastname: Stern
authors.forename: Jean
authors.initials: J
authors.lastname: Mukherjee
authors.forename: Richard M
authors.initials: RM
authors.lastname: Jakowski
authors.forename: Linda A
authors.initials: LA
authors.lastname: Ross
mesh_terms: D000818:Animals; D003176:Complement C3 / Q000032:analysis*; D004283:Dog Diseases / Q000097:blood* / Q000378:metabolism; D004285:Dogs / Q000097:blood* / Q000276:immunology; D006262:Health; D007674:Kidney Diseases / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D012016:Reference Values
chemical_list: D003176:Complement C3