Pattern of Coombs' test reactivity has diagnostic significance in dogs with immune-mediated haemolytic anaemia.
OBJECTIVE
To investigate the clinical significance of the pattern of Coombs' test reactivity in dogs with immune-mediated haemolytic anaemia.


METHODS
Sixty-five anaemic dogs with a positive Coombs' test were included. Coombs' testing was performed at 4 and 37 degrees C with polyvalent canine Coombs' reagent and antisera specific for each of canine immunoglobulin G, immunoglobulin M and complement factor C3. The impact of performing testing with only polyvalent antiserum at 37 degrees C was assessed. Chi-squared tests were used to compare Coombs' test reactivity in dogs with primary immune-mediated haemolytic anaemia (group A) and in dogs with concurrent/underlying disease (group B). Following Bonferroni correction, significance was set at P < or = 0.003.


RESULTS
Eleven dogs would have been regarded as Coombs' negative had they been tested with polyvalent antiserum at 37 degrees C alone. Group A dogs were significantly more likely to be positive with polyvalent antiserum and/or anti-dog immunoglobulin G at 4 and/or 37 degrees C (P < or = 0.001) and tended to be less likely to be positive with anti-dog immunoglobulin M at 4 degrees C (P=0.040).


CONCLUSIONS
Testing of anaemic dogs with polyvalent Coombs' reagent at 37 degrees C was less sensitive than testing with monovalent reagents at 4 and 37 degrees C. The pattern of Coombs' test reactivity differed significantly between dogs with primary immune-mediated haemolytic anaemia and those with concurrent/underlying disease.
Department of Clinical Veterinary Science, University of Bristol, Langford, Bristol, UK.
S M
SM
Warman
J K
JK
Murray
A
A
Ridyard
J
J
Eastwood
S
S
Silva
M J
MJ
Day
D000744:Anemia, Hemolytic, Autoimmune / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D000818:Animals; D003176:Complement C3 / Q000032:analysis / Q000276:immunology; D003298:Coombs Test / Q000662:veterinary*; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D004285:Dogs; D005260:Female; D007106:Immune Sera; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008297:Male; D012680:Sensitivity and Specificity; D013696:Temperature; D006113:United Kingdom
D003176:Complement C3; D007106:Immune Sera; D007074:Immunoglobulin G; D007075:Immunoglobulin M