ISSN 2398-2950      

Direct Coombs' test

ffelis
Contributor(s):

Karen Gerber

Michael Day

Synonym(s): Direct antiglobulin test


Overview

Sampling

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Tests

Methodologies

  • Patients red cells are washed then mixed with antiserum containing antibodies against feline immunoglobulins (IgG, IgM) and complement (polyvalent feline Coombs' reagent) and titrated to dilutions of at least 1 in 10,000.
  • Also titrate individual antisera against feline IgG, IgM.
  • Incubate at 37°C for 1 hour. Ideally test performed in duplicate also at 4°C.
  • Observe for agglutination. (Small red flecks of agglutinated cells are seen suspended in the solution in the well. If there is no agglutination, a large red dot is seen in the bottom of the well.)

Availability

  • Most commercial veterinary laboratories (but generally only polyvalent reagent is used at 37°C with limited titration).

Validity

Sensitivity

Specificity

Technique (intrinsic) limitations

Technician (extrinsic) limitations

False negatives may result from incorrect laboratory procedures

  • Reagents not specific to feline immunoglobulins.
  • Test performed at incorrect temperature.
  • Prozone phenomenon: if the anti-immunglobulins used in the test bind the antibody-coated cells too avidly, then agglutination may be prevented. Overcome by routinely performing test at serum dilutions up to 1:10,000.

Result Data

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from VetMedResource and PubMed.
  • Stokal T & Blue J T (1999) Pure red cell aplasia in cats: 9 cases (1989-1997). JAVMA 214, 75-79.
  • Gunn-Moore D, Day M J, Graham M E A, Cue S M & Harbour D A (1999) Immune-mediated haemolytic anaemia in two sibling cats associated with multicentric lymphoblastic infiltration. JFMS 1, 209-214.
  • Person J M et al (1997) Les anemies hemolytiques auto-immunes dans le chat. Revue Med Vet 148 (2), 107-114.
  • Eibert M & Lewis D C (1997) Evaluation of the feline erythron in health and disease. Comp Cont Educ Pract Vet 19, 335-347.
  • Day M J (1996) Diagnostic assessment of the feline immune system. Part 2. Feline Practice 24, 14-25.

Other sources of information

  • Day M J (1999) Clinical Immunology of the dog and cat. Manson Publishing, UK. ISBN: 1 8745 4598 7.

MEMBER BENEFIT

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code