title: Evaluation of Serum Aspergillus-Specific Immunoglobulin A by Indirect ELISA for Diagnosis of Feline Upper Respiratory Tract Aspergillosis.
abstract: BACKGROUND
  Serological tests for diagnosis of aspergillosis in immunocompetent humans and animals are based on Aspergillus-specific IgG (As-IgG). In humans with chronic pulmonary aspergillosis, As-IgA may be detectable even if IgG titers are negative. Cats with upper respiratory tract aspergillosis (URTA) have detectable As-IgG, but their ability to mount an IgA response and its diagnostic utility are unknown.
  
  
  OBJECTIVE
  To determine whether serum As-IgA can be detected in cats with URTA and evaluate its diagnostic utility alone or combined with As-IgG.
  
  
  METHODS
  Twenty-three cats with URTA (Group 1), 32 cats with other respiratory diseases (Group 2), and 84 nonrespiratory controls (Group 3).
  
  
  METHODS
  Serum As-IgA and As-IgG was measured by indirect ELISA. Optimal cutoff values were determined by receiver-operating curve analysis. Sensitivity (Se) and specificity (Sp) for URTA diagnosis were determined.
  
  
  RESULTS
  Serum IgA was detected in 91.3% of Group 1 cats. The Se of IgA detection was 78.3% and Sp was 96.9% for Group 2, 85.7% for Group 3 and 88.8% for Group 2 and 3 combined. Assay Se for IgG was 100% and Sp was 92.2%. Using combined IgA and IgG results at cutoffs optimized for Sp for IgA and Se for IgG and combined controls (Groups 2 and 3), Se for diagnosis was 100% and Sp was 91.4%.
  
  
  CONCLUSIONS
  Most cats with URTA have serum As-IgA antibodies that can be detected by ELISA. Paired measurement of serum As-IgA and IgG shows no benefit for diagnosis of feline URTA over IgG alone.
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors: A
authors: A
authors: Taylor
authors: TDDS ltd., The Innovation Centre, University of Exeter, Devon, UK.
authors: I
authors: I
authors: Peters
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors: N K
authors: NK
authors: Dhand
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors: J
authors: J
authors: Whitney
authors: School of Veterinary Medicine, University of California, Davis, CA.
authors: L R
authors: LR
authors: Johnson
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors: J A
authors: JA
authors: Beatty
authors: Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia. vanessa.barrs@sydney.edu.au.
authors: V R
authors: VR
authors: Barrs
mesh_terms: D000818:Animals; D001228:Aspergillosis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D001230:Aspergillus / Q000145:classification / Q000276:immunology; D002371:Cat Diseases / Q000175:diagnosis* / Q000382:microbiology; D002415:Cats; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005260:Female; D007070:Immunoglobulin A / Q000097:blood*; D008297:Male; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000662:veterinary*; D012680:Sensitivity and Specificity
chemical_list: D007070:Immunoglobulin A
keywords: 
  Aspergillus
  ; Aspergillosis; Feline; Sino-nasal; Sino-orbital