Antinuclear Antibody Test (ANA)

Species: Canine, feline

Specimen: 5 mL serum

Container: Red top or gel tube

Collection protocol: Venepuncture

Special handling/shipping requirements: Standard

General information about the disease: This serum test detects the presence or absence of antibody to various nuclear antigens.

General information about when this test is indicated:

It is mostly indicated in cases of suspected systemic lupus erythematosus (SLE), where loss of immune autoregulation results in the production of antibodies against a range of membrane and soluble antigens. The most characteristic of these are the antinuclear antibodies directed against double-stranded DNA, RNA, nucleoprotein and histone-related antigens.

The test is mostly applicable to dogs and a positive ANA titre needs to be interpreted in light of supportive clinical signs (e.g. polyarthritis, skin disease) and laboratory findings (e.g. proteinuria, haematological abnormalities such as thrombocytopaenia, anaemia or leukopaenia) that may also be seen with SLE. Negative results are uncommon and do not necessarily rule out SLE. Positive ANA titres are non-specific and can also be present in a variety of disease states such as infectious and non-immune-mediated inflammatory diseases. They can also be induced by some therapeutic drugs as well as occasionally being present in normal individuals. These ANA titres are generally weak or transitory.

A cat ANA test is also available.