An indirect flow cytometric test for detection of anti-neutrophil antibodies in dogs.
OBJECTIVE
To develop a clinically applicable assay for detection of serum anti-neutrophil antibodies in dogs.


METHODS
Serum samples of 20 healthy dogs and 20 sick dogs.


METHODS
An indirect immunofluorescence assay was developed in which canine serum was incubated with paraformaldehyde-fixed neutrophils and subsequently incubated with fluorescein-conjugated rabbit anti-dog IgG. Neutrophil median fluorescence intensity and the percentage of neutrophils with an increase in fluorescence intensity were determined by use of a flow cytometer.


RESULTS
Neutrophils incubated with serum from healthy and sick dogs had a normally distributed curve when displayed as a histogram. Alloantibodies or immune complexes that significantly affected test results were not detected. Hyperglobulinemia did not appear to affect test results. The neutrophil donor did not significantly affect test results. With 1 exception, results for the sick dogs did not differ appreciably from those for healthy dogs. Serum from a dog with steroid-responsive neutropenia had a greater neutrophil fluorescence value and percentage of neutrophils with an increase in fluorescence intensity, compared with either healthy or sick dogs.


CONCLUSIONS
The indirect immunofluorescence test gave consistent results for healthy and sick dogs and detected anti-neutrophil antibodies in a dog with steroid-responsive neutropenia. Definitive evaluation of the test will be dependent on evaluation of persistently neutropenic dogs and correlation of test results with a response to immunosuppressive therapy.
Weiss
Douglas J
DJ
Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA.
D000818:Animals; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis; D004285:Dogs / Q000097:blood / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods / Q000662:veterinary*; D009503:Neutropenia / Q000175:diagnosis / Q000662:veterinary
D019268:Antibodies, Antineutrophil Cytoplasmic