title: Serum haptoglobin concentration in swine naturally or experimentally infected with Actinobacillus pleuropneumoniae.
abstract: Serum haptoglobin (Hp) concentrations were measured in swine that were naturally or experimentally infected with Actinobacillus pleuropneumoniae. In swine from a specific-pathogen-free herd, mean serum concentration of Hp (+/- SD) was 5.79 +/- 1.06 mg of cyanmethemoglobin-binding capacity (CHBC)/dl. Serum Hp concentrations in paired samples were measured at 7-day intervals in 40 swine randomly selected from a conventional herd that was experiencing an acute episode of pneumonia and deaths caused by A pleuropneumoniae serotype-5 infection. Day-0 and -7 serum Hp concentrations were 24.58 +/- 1.38 and 23.10 +/- 1.12 mg of CHBC/dl, respectively, with no significant difference between these measurements. In a second conventional herd with a history of chronic infection with A pleuropneumoniae serotype 5, serum concentrations of Hp measured in paired samples obtained 6 days apart were 12.36 +/- 0.81 and 18.63 +/- 0.76 mg of CHBC/dl, respectively, and were significantly (P < 0.05) different from each other. Twenty-nine 12-week-old conventional swine were challenged intranasally with A pleuropneumoniae serotype 1 (n = 19) and serotype 5 (n = 10). Serum Hp concentration increased from prechallenge concentrations of 7.49 +/- 1.38 and 15.10 +/- 1.22 mg of CHBC/dl, respectively, to 41.01 +/- 1.35 and 22.37 +/- 1.78 mg of CHBC/dl, respectively, 72 hours after challenge. For these 29 swine, serum Hp concentration was positively correlated with rectal temperature (r = 0.34; P < 0.001) during the immediate postchallenge period.
authors.affiliation: Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61801.
authors.forename: W F
authors.initials: WF
authors.lastname: Hall
authors.forename: T E
authors.initials: TE
authors.lastname: Eurell
authors.forename: R D
authors.initials: RD
authors.lastname: Hansen
authors.forename: L G
authors.initials: LG
authors.lastname: Herr
mesh_terms: D000189:Actinobacillus Infections / Q000097:blood / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae; D000818:Animals; D001831:Body Temperature; D006242:Haptoglobins / Q000032:analysis*; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000097:blood*
chemical_list: D006242:Haptoglobins