Nuclear Antibodies (ANA)
|
Assay |
Anti-nuclear antibodies (ANA) |
|
Key Words |
Anti-Nuclear antibody (ANA) screen , ANA (CTD) |
|
Specimen Collection |
Serum (brown) |
|
Turnaround time |
5 days (10 days for HEp-2) |
|
Test indications |
These are a heterogeneous group of antibodies that bind to nuclear antigens. ANA negative SLE is extremely rare. However the test is not specific for SLE as anti nuclear antibodies can occur in other conditions e.g. rheumatoid arthritis, systemic sclerosis, chronic active hepatitis, juvenile arthritis, Sjögren’s syndrome, MCTD, fibrosing alveolitis, systemic infections and can be induced by drugs such as hydralazine. Low titre ANAs can also be found in the serum of many healthy elderly people. |
|
Minimum retesting interval |
Requests made within 60 days of a previous request on a patient are intervened. |
|
Methodology |
Frontline screen: Fluoroenzyme immunoassay The antibodies screened for in this assay include: dsDNA, U1RNP (RNP70, A, C), Ro52, Ro60, La (SS-B), Scl-70, Centromere B, Jo-1, Fibrillarin, RNA Pol III, Ribosomal-P, PM-Scl, PCNA, Mi-2 proteins and Sm proteins.
Confirmationary testing:ENA screen, dsDNA, ENA profile by enzyme immunoassay (EIA) and HEp-2 by indirect immunofluorescence (IFA). |
|
Interferences |
No known methodological interferences |
|
Reference Range |
Negative : <0.7 Equivocal : 0.7-1.0 Positive : >1.0 |
|
Analytical error |
Contact Immunology laboratory (x8454) |
|
Reference change value |
N/A |
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Other information |
