Antinuclear antibody screen
| Category | Immunology |
|---|---|
| Test background |
Commonly positive at high titre (>1:640) in patients with SLE and other connective tissue diseases. The presence of ANA is indicative of SLE (present in 80-90 % of cases) although they also appear in some other autoimmune diseases, such as Sjögren’s syndrome (60 %), rheumatoid arthritis, autoimmune hepatitis, scleroderma and poly/dermatomyositis, Hashimoto’s disease and autoimmune haemolytic anaemia. Weak positive reactions are not uncommon and may have no clinical significance. |
| Clinical Indications |
ANA should be requested for investigations of suspected connective tissue autoimmune syndromes. Autoantibody screening should be reserved for investigations where there is suspected liver involvement and/or anaemia. Autoimmune symptoms are typically variable and include: painful or swollen joints unexplained fever back pain extreme fatigue rashes |
| Reference range | Negative |
| Sample & container required | RST (rust top) |
| Sample volume | 5-10 mL (1 mL serum) |
| Turnaround time | 4 days |
| Notes | This test is currently unaccredited due to a recent change in platform. |