Flow cytometric immunophenotype of canine lymph node aspirates.

Area of Science:

• Veterinary immunology
• Canine pathology
• Flow cytometry applications

Background:

• Advances in reagent availability enhance understanding of canine lymphocyte biology and pathology.
• Flow cytometry is a common method for assessing circulating lymphocytes, but lymph node aspirates are also suitable.
• Needle aspirates offer a minimally invasive approach for lymph node analysis.

Purpose of the Study:

• To determine the feasibility of immunophenotyping canine lymph node aspirates using flow cytometry.
• To establish reference intervals for lymphocyte subsets in normal dogs.
• To assess the diagnostic utility of this technique for canine lymphoma.

Main Methods:

• Collected lymph node aspirates from 32 normal dogs and 6 dogs with lymphoma.
• Performed microscopic examination of stained smears for cell morphology and inflammation.
• Analyzed cell surface antigen expression via flow cytometry on at least 10,000 events per sample.
• Assessed sample stability after overnight storage at 4°C.

Main Results:

• Adequate samples were obtained from 30 of 32 clinically normal dogs.
• Immunophenotyping results were consistent after 24 hours of sample storage.
• Established reference intervals for lymphocyte subsets (CD3+, CD4+, CD8+, CD21+) in normal dogs.
• Lymph node aspirates from dogs with lymphoma were readily classified by flow cytometry.

Conclusions:

• Lymph node aspiration is a feasible method for comprehensive flow cytometric analysis in dogs.
• This technique is applicable for the immunophenotyping and diagnosis of canine lymphoma.
• The findings support the use of lymph node aspirates for routine diagnostic workups in veterinary oncology.