Anti-Nuclear Antibody (ANA) by IFA - End Point Titer
Understanding Anti-Nuclear Antibody (ANA) by IFA - End Point Titer
What is Anti-Nuclear Antibody (ANA) by IFA - End Point Titer?
Anti-Nuclear Antibody (ANA) by IFA - End Point Titer test refers to antinuclear antibody (ANA) detection by indirect fluorescent antibody (IFA) method to detect the presence of ANA in blood. ANAs are autoantibodies that attack the body’s healthy cells and cause damage to the joints, skin, muscles, and other body parts. This test is suggested to people at risk or having autoimmune disorders such as rheumatoid arthritis, autoimmune hepatitis, scleroderma and systemic lupus erythematosus (SLE), etc.
Most people have a minor percentage of ANA in their blood; however, elevated ANA levels can be a sign of an autoimmune disease. A negative result does not completely rule out the possibility of autoimmune disease.
What is Anti-Nuclear Antibody (ANA) by IFA - End Point Titer used for?
· To determine the presence of an autoimmune disease like Systemic Lupus Erythematosus (SLE)
· To evaluate the possible presence of autoimmune Connective Tissue Disorders (CTDs) other than SLE such as Polymyositis, Scleroderma, Sjögren's syndrome etc.
Interpreting Anti-Nuclear Antibody (ANA) by IFA - End Point Titer results
Interpretations
The appearance of fluorescence is a positive result and indicates the presence of antinuclear antibodies.
The absence of fluorescence is a negative result and indicates the absence of antinuclear antibodies.
Positive results of IFA are expressed in two parts: as titers which are ratios that represent the highest dilution of the blood sample at which antinuclear antibodies were visible, and as the fluorescent pattern seen. Titer value indicates the amount of antinuclear antibodies in the blood, while the pattern of fluorescence indicates different autoimmune diseases.
Some common fluorescence patterns and autoimmune conditions associated with them include:
FLUORESCENCE PATTERN |
ASSOCIATED CONDITIONS |
Homogenous or diffuse |
SLE, drug-induced lupus, and mixed connective tissue disease |
Nucleolar |
Scleroderma or Polymyositis |
Speckled |
SLE, Sjögren syndrome, Scleroderma, Polymyositis, Rheumatoid Arthritis, and mixed connective tissue disease |
Centromere or peripheral |
Scleroderma and CREST Syndrome (Calcinosis, Raynaud syndrome, Esophageal dysmotility, Sclerodactyly, Telangiectasia) |