Final answer:
The four extractable nuclear antigens often associated with autoimmune diseases are Anti-Sm antibodies, anti-double-stranded DNA antibodies, anti-SSA/Ro antibodies, and anti-SSB/La antibodies. These antigens are typically identified using the IFA test to detect ANAs, which is crucial for the diagnosis of conditions like SLE where these antibodies are prominently featured.
Step-by-step explanation:
The four extractable nuclear antigens commonly associated with autoimmune diseases are:
- Anti-Sm antibodies (targets small nuclear ribonucleoproteins)
- Anti-double-stranded DNA antibodies (anti-ds-DNA)
- Anti-SSA/Ro antibodies
- Anti-SSB/La antibodies
These antigens are frequently measured through laboratory tests such as the indirect immunofluorescence assay (IFA) for the detection of antinuclear antibodies (ANAs), which is an important tool in the diagnosis of these diseases. Systemic lupus erythematosus (SLE) is one of the autoimmune disorders characterized by elevated expression levels of ANAs.
The presence of anti-ds-DNA and anti-Sm antibodies is unique to patients with SLE and are included in the classification criteria for the disease. Autoantibodies in SLE lead to type III hypersensitivity reactions, causing damage and pathology through immune complex formation, which then results in tissue damage and inflammation.