2496. ANA. Screen systemic connective tissue diseases (qualitative determination)

ANA. SCREENING FOR SYSTEMIC CONNECTIVE TISSUE DISEASES – combines the detection of autoantibodies to soluble nuclear components. The latter are a characteristic feature of autoimmune connective tissue disorders. It is one of the most commonly used screening tests in the diagnosis of autoimmune diseases.

Specific autoantibodies to soluble nuclear components of the cell (ribonucleoproteins) are normally absent. In autoimmune disorders, the immune system begins to produce specific immunoglobulins against its own cells and their components; therefore, the detection of ENA antibodies is of great importance in the diagnosis of systemic rheumatic diseases.

In the qualitative format, this test is used as a screening test to determine the presence or absence of autoimmune connective tissue diseases. If necessary for the differential diagnosis of systemic connective tissue diseases, the test can be performed in a quantitative format.

Antinuclear antibodies are detected in more than 90% of patients with diffuse connective tissue diseases (SLE, systemic sclerosis, mixed connective tissue disease, and Sjögren’s syndrome). Most ANA are likely a secondary phenomenon related to tissue destruction. The mechanism of ANA induction is associated with activation of apoptosis in keratinocytes, lymphocytes, and other cells in diffuse connective tissue diseases, as well as sensitization of the body to nuclear antigens.

The analysis allows specific ENA antibodies to be detected at their lowest concentrations in the blood serum. They may be present either together or individually. Some ANA subtypes occur in a single disease or in overlap syndromes.

• For the diagnosis of systemic connective tissue diseases.
• For monitoring disease course and assessing disease progression in rheumatic diseases (quantitative testing).

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: