title: Systemic Amyloid A Amyloidosis in Island Foxes (Urocyon littoralis): Severity and Risk Factors.
abstract: Systemic amyloid A (AA) amyloidosis is highly prevalent (34%) in endangered island foxes (Urocyon littoralis) and poses a risk to species recovery. Although elevated serum AA (SAA) from prolonged or recurrent inflammation predisposes to AA amyloidosis, additional risk factors are poorly understood. Here we define the severity of glomerular and medullary renal amyloid and identify risk factors for AA amyloidosis in 321 island foxes necropsied from 1987 through 2010. In affected kidneys, amyloid more commonly accumulated in the medullary interstitium than in the glomeruli (98% [n= 78 of 80] vs 56% [n= 45], respectively;P< .0001), and medullary deposition was more commonly severe (19% [n= 20 of 105]) as compared with glomeruli (7% [n= 7];P= .01). Univariate odds ratios (ORs) of severe renal AA amyloidosis were greater for short- and long-term captive foxes as compared with free-ranging foxes (ORs = 3.2, 3.7, respectively; overall P= .05) and for females as compared with males (OR = 2.9;P= .05). Multivariable logistic regression revealed that independent risk factors for amyloid development were increasing age class (OR = 3.8;P< .0001), San Clemente Island subspecies versus San Nicolas Island subspecies (OR = 5.3;P= .0003), captivity (OR = 5.1;P= .0001), and nephritis (OR = 2.3;P= .01). The increased risk associated with the San Clemente subspecies or captivity suggests roles for genetic as well as exogenous risk factors in the development of AA amyloidosis.
authors.affiliation: Departments of Pathology and Medicine, University of California-San Diego, La Jolla, CA, USA Department of Pathology, Immunology, and Microbiology, University of California-Davis, Davis, CA, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Gaffney
authors.affiliation: Wildlife Disease Laboratories, Institute for Conservation Research, San Diego Zoo Global, Escondido, CA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Witte
authors.affiliation: Wildlife Investigations Laboratory, California Department of Fish and Wildlife, Rancho Cordova, CA, USA Department of Veterinary Medicine and Epidemiology, University of California-Davis, Davis, CA, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Clifford
authors.affiliation: Department of Pathology, Immunology, and Microbiology, University of California-Davis, Davis, CA, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Imai
authors.affiliation: Veterinary Population Medicine Department, Veterinary Diagnostic Laboratory, University of Minnesota, St Paul, MN, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: O'Brien
authors.affiliation: Departments of Pathology and Neuroscience, University of California-San Diego, La Jolla, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Trejo
authors.affiliation: Institute for Pharmaceutical Biotechnology, Ulm University, Helmholtzstrasse, Ulm, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Liberta
authors.affiliation: Institute for Pharmaceutical Biotechnology, Ulm University, Helmholtzstrasse, Ulm, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Annamalai
authors.affiliation: Institute for Pharmaceutical Biotechnology, Ulm University, Helmholtzstrasse, Ulm, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Fändrich
authors.affiliation: Departments of Pathology and Neuroscience, University of California-San Diego, La Jolla, CA, USA.
authors.forename: E
authors.initials: E
authors.lastname: Masliah
authors.affiliation: Department of Pathology, Immunology, and Microbiology, University of California-Davis, Davis, CA, USA Deceased Supplemental material for this article is available on the Veterinary Pathology website at http://vet.sagepub.com/supplemental.
authors.forename: L
authors.initials: L
authors.lastname: Munson
authors.affiliation: Departments of Pathology and Medicine, University of California-San Diego, La Jolla, CA, USA Department of Pathology, Immunology, and Microbiology, University of California-Davis, Davis, CA, USA csigurdson@ucsd.edu.
authors.forename: C J
authors.initials: CJ
authors.lastname: Sigurdson
mesh_terms: D000686:Amyloidosis / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D056727:Endangered Species; D005260:Female; D005589:Foxes; D007249:Inflammation / Q000662:veterinary; D007668:Kidney / Q000378:metabolism; D016015:Logistic Models; D008297:Male; D009393:Nephritis / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D012307:Risk Factors; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D012720:Severity of Illness Index
chemical_list: D000685:Serum Amyloid A Protein
keywords: Urocyon littoralis; amyloid A; amyloidosis; endangered species; island fox; logistic regression; nephritis; serum amyloid A