Anti-nuclear antibodies
In medicine, especially rheumatology, anti-nuclear antibodies are "autoantibodies directed against various nuclear antigens including DNA, RNA, histones, acidic nuclear proteins, or complexes of these molecular elements. Antinuclear antibodies are found in systemic autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, scleroderma, polymyositis, and mixed connective tissue disease.[1]
Screening tests
A first and indirect measurement of these antibodies was the 1940-vintage lupus cell preparation, a microscopic procedure no longer used. In modern practice, the basic screening test is the anti-nuclear antibody titer (ANA). While not specific, a high ANA values suggests an autoimmune disease is present; it does not, however, exclude them. High values then justify more specific tests:[2]
Its sensitivity, in specific diseases, is:
- Autoimmune
- Systemic lupus erythematosus 96-100%
- Scleroderma 60-80%
- Mixed connective tissue disease 100%
- Polymyositis and dermatomysitis 61%
- Rheumatoid arthritis 52&
- Rheumatoid vasculitis 30-50%
- Sjogren's syndrome 40-70%
- Drug-induced lupus 100%
- Discoid lupus 15%
- Pauciarticular juvenile chronic arthritis 71%
- Non-rheumatic
Specific clinical tests
- Anti-single-stranded DNA antibodies (ssDNA)
- Anti-double-stranded DNA antibodies (dsDNA)
- Antihistone antibodies
- Anti-centromere antibodies are present principally with limited cutaneous systemic sclerosis, especially those presenting with the CREST syndrome; they are seen in subtypes of systemic sclerosis, such as Reynaud's phenomenon
- Anti-Smith (anti-Sm)
- Anti-ribonucleoprotein antibodies (anti-RNP)
- Antiphospholipid antibodies
Specialized tests
References
- ↑ Anonymous (2024), Anti-nuclear antibodies (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Peter H. Schur and Rober H. Scherling (2004), Chapter 5: Laboratory tests in rheumatic disorders, Practical Rheumatology (Third ed.), Mosby, ISBN 03230299396, p. 59