Flow cytometric detection of alpha-1-acid glycoprotein on feline circulating leucocytes

Area of Science:

• Veterinary Immunology
• Clinical Pathology

Background:

• Alpha-1-acid glycoprotein (AGP) is an acute-phase protein with a known role in inflammation.
• The presence and significance of AGP on feline leucocytes, particularly in relation to specific diseases, remain largely unexplored.

Purpose of the Study:

• To determine if alpha-1-acid glycoprotein (AGP) is detectable on the surface of circulating leucocytes in cats.
• To investigate the association between AGP-positive leucocytes and various feline diseases, including feline coronavirus (FCoV) infection and feline infectious peritonitis (FIP).

Main Methods:

• Flow cytometry was employed to detect AGP on feline leucocytes using an anti-feline AGP antibody.
• Serum protein electrophoresis, routine haematology, and serum AGP concentration measurements were conducted.
• Statistical analysis (Chi-square test) was used to compare the proportion of cats with AGP-positive leucocytes across different groups.

Main Results:

• AGP-positive leucocytes were identified in 23% of the cats studied.
• A higher proportion of AGP-positive granulocytes and monocytes was observed in sick cats, especially those with non-FIP diseases, and in cats with elevated serum AGP concentrations.
• No significant association was found between AGP-positive leucocytes and feline coronavirus (FCoV) seropositivity or leucocytosis.

Conclusions:

• The study confirms the presence of AGP on feline leucocytes, particularly in inflammatory conditions.
• No correlation was established between AGP-positive leucocytes and feline infectious peritonitis (FIP).
• Further research is warranted to understand the underlying mechanisms and potential diagnostic utility of AGP-positive leucocytes in feline inflammatory diseases.