From the Guidelines
Yes, a patient can be ANA positive and lupus test positive without having Systemic Lupus Erythematosus (SLE).
Key Points
- The presence of ANA (antinuclear antibodies) is not exclusive to SLE and can be found in other autoimmune diseases and even in healthy individuals 1.
- The EULAR/ACR 2019 classification criteria for SLE require a positive ANA test as an entry criterion, but this does not necessarily mean that a patient with a positive ANA test has SLE 1.
- Anti-dsDNA autoantibodies are also not specific to SLE and can be found in other conditions, including infections and other autoimmune diseases 1.
- The sensitivity and specificity of ANA and anti-dsDNA tests can vary depending on the assay used and the population being tested, which can lead to false positives and false negatives 1.
- A positive ANA test should be used as a screening tool to select additional assays to assess other parameters, and confirmatory testing of anti-ENA is recommended when ANAs are positive in the diagnosis process 1.
- Clinical suspicion and additional testing are necessary to confirm a diagnosis of SLE, even in patients with positive ANA and lupus tests 1.
- The use of standardized terminology and reference methods for ANA and anti-dsDNA testing can help improve the accuracy and consistency of test results 1.
From the Research
ANA Positive and Lupus Test Positive without SLE
- A patient can be ANA positive and lupus test positive without having Systemic Lupus Erythematosus (SLE) 2, 3, 4.
- ANA testing is performed to help diagnose patients who have clinical symptoms suggestive of possible autoimmune diseases, but a positive ANA test may also be seen with non-autoimmune inflammatory diseases, including both acute and chronic infections 2.
- Up to 20-30% of the healthy population, depending on the assay used, is positive for an ANA, complicating the use of this test for diagnosis or the detection of preclinical autoimmunity 3.
- ANA positive individuals suspected of having a connective tissue disease present a wide variety of symptoms and findings, usually at the 4th to 5th decade of life, but may not fulfill SLE classification criteria 4.
- Some patients with SLE may initially present with negative serology, including negative ANA, LE cell test, and anti-DNA, but may become positive over time 5.
Clinical Features and Serum Biomarkers
- Incomplete lupus erythematosus (ILE) has been defined as a subset of patients who have some SLE-specific clinical manifestations but do not meet currently accepted classification criteria for SLE 6.
- Clinical features, serum and tissue biomarkers, such as increased autoantibody diversity, presence of anti-double-stranded DNA (dsDNA) antibodies, and high expression of type I and type II interferon (IFN)-gene products, can distinguish those patients with ILE at risk of transitioning to SLE from those who will not 6.
- Certain serum cytokines and complement products have been identified as markers with positive predictive value, particularly when combined together 6.