title: Two major ruminant acute phase proteins, haptoglobin and serum amyloid A, as serum biomarkers during active sheep scab infestation.
abstract: Two ruminant acute phase proteins (APPs), haptoglobin (Hp) and serum amyloid A (SAA), were evaluated as serum biomarkers (BMs) for sheep scab-a highly contagious ectoparasitic disease caused by the mite Psoroptes ovis, which is a major welfare and production threat worldwide. The levels of both APPs increased in serum following experimental infestation of sheep with P. ovis, becoming statistically significantly elevated from pre-infestation levels at 4 weeks post-infestation. Following successful treatment of infested sheep with an endectocide, Hp and SAA serum levels declined rapidly, with half lives of less than 3 days. In contrast, serum IgG levels which specifically bound the P. ovis-derived diagnostic antigen Pso o 2 had a half-life of 56 days. Taking into account pre-infestation serum levels, rapidity of response to infestation and test sensitivity at the estimated optimum cut-off values, SAA was the more discriminatory marker. These studies illustrated the potential of SAA and Hp to indicate current sheep scab infestation status and to augment the existing Pso o 2 serological assay to give disease-specific indications of both infestation and successful treatment.
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Midlothian EH26 0PZ, UK. beth.wells@moredun.ac.uk.
authors.forename: Beth
authors.initials: B
authors.lastname: Wells
authors.forename: Giles T
authors.initials: GT
authors.lastname: Innocent
authors.forename: Peter D
authors.initials: PD
authors.lastname: Eckersall
authors.forename: Eilidh
authors.initials: E
authors.lastname: McCulloch
authors.forename: Alasdair J
authors.initials: AJ
authors.lastname: Nisbet
authors.forename: Stewart T G
authors.initials: ST
authors.lastname: Burgess
mesh_terms: D056810:Acaricides / Q000494:pharmacology; D000818:Animals; D000941:Antigens / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western / Q000662:veterinary; D003124:Colorimetry / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D006242:Haptoglobins / Q000378:metabolism*; D007559:Ivermectin / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D008924:Mite Infestations / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D040042:Psoroptidae / Q000502:physiology*; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy / Q000469:parasitology*; D012871:Skin Diseases / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*
chemical_list: D056810:Acaricides; D000941:Antigens; D015415:Biomarkers; D006242:Haptoglobins; D000685:Serum Amyloid A Protein; D007559:Ivermectin; C084101:doramectin