Overview of Anti Nuclear Antibody
What is Anti Nuclear Antibody?
Preparation for Anti Nuclear Antibody
- No special preparation required
Why Get Tested for Anti Nuclear Antibody?
The Antinuclear Antibody Test is performed:
· 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.
Understand more about Anti Nuclear Antibody
The immune system of the body is responsible for recognition of the body’s own cells and identification of foreign cells like pathogens which are then targeted and destroyed. Autoimmune disorders are conditions where the immune system of the body is unable to recognize certain cells as the body’s own cells and starts an immune response against them which results in their destruction. The recognition of ‘self’ and ‘non-self’ cells is mediated by certain proteins present on the surface of cells or inside them. When the immune system identifies a cell as foreign or ‘non-self’, it produces antibodies against these cells to destroy them. Antibodies produced in an autoimmune disease are called autoantibodies.
Antinuclear antibodies (ANA) are autoantibodies that are produced against protein markers present in the nucleus of certain cells of the body. They are produced in a number of autoimmune diseases but are most commonly produced in Systemic Lupus Erythematosus (SLE).
The Antinuclear Antibody Test can be performed either by Immunoassay method (ELISA) or Indirect Fluorescent Antibody (IFA) method to detect ANA in blood. Both these tests may be used by some laboratories together: the Immunoassay method (ELISA) to screen for the presence of antinuclear antibodies, and IFA method subsequently to confirm the positive or equivocal Immunoassay results.
ANA by Immunoassay method (ELISA) utilizes a mixture of known anti-nuclear antigens and is fairly simple to perform, can be automated and provides fairly objective results.
What Results of Anti Nuclear Antibody mean?
Results are provided as positive/negative or with an index value against a cutoff value.
A positive ANA test can also be seen in healthy individuals, particularly the elderly or in diseases other than Connective Tissue Disorders (CTD), where it has no diagnostic value.