Antinuclear antibodies

Antinuclear antibodies

Antinuclear antibodies

1. These are antibodies that bind to various nuclear antigens.they are generally detected using indirect immunofluorescence. Most laboratories employ a HEp-2 cell line.
2. Higher titres of ANA  are more likely to be true -positive than low titres.
3. ANA is  positive in several conditions. In SLE and drug -



induced lupus, its sensitivity is more than 90%.
4. A negative  ANA test does not exclude SLE. Rarely, patients with anti-Ro antibodies have a negativeANA.
5. Titres of ANA do not correlate with disease activity and should not be used to monitor the course of SLE or other diseases.

Conditions associated with a positive ANA test.
1. Systemic lupus erythematosus.
2. Systemic sclerosis.
3 .Sjogren's syndrome.
4. Mixed connectivetissue disease.
5. Lives disease.
6. Rheumatic arthritis.
7. Bacterial endocarditis.
8. Malignancies.

The nuclear pattern of a positive ANA is also important. This pattern reflects the intrantalfas target of ANA.
Various patterns are.
1. Homogeneous pattern-highly suggestive of SLE.
2. Rim pattern -highly suggestive of SLE.
3. Speckled pattern - common with Sjogren's symdrome and mixed connective tissue diseases.
4. Nucleolar pattern-common in systemic sclerosis.