Can you have scleroderma with negative antibodies?
People with localized scleroderma usually have negative ANA. The ANA test also helps determine which kind of scleroderma you have or are likely to develop based on your blood tests. There are 3 main antibodies in systemic scleroderma.
What does a positive anti-SCL-70 mean?
A positive test result for Scl 70 antibodies is consistent with a diagnosis of scleroderma.
Can SCL 70 be a false positive?
Scl-70 (topo-1) is a DNA binding protein and anti-DNA/DNA complexes in the sera of SLE patients may bind to topo-I, leading to a false-positive result. The presence of Scl-70 antibody in sera may also be due to contamination of recombinant Scl-70 with DNA derived from cellular material used in immunoassays.
Can you have an autoimmune disease with a negative ANA?
The American College of Rheumatology (ACR) recommends IFA as the gold standard method for ANA testing. A negative ANA IFA result suggests that ANA-associated autoimmune diseases are not present, but does not rule out the possibility.
How are anti Scl-70 antibodies derived from topoisomerase?
Anti-Scl-70 antibodies. The etymology of scl-70 consists of an abbreviation of scl eroderma and a 70 kD extractable immunoreactive fragment that can be obtained from the otherwise larger (100–105 kD) target topoisomerase antigen (called the SCL-70 Antigen) of the antibodies.
How to test for scl70 antibodies, IgG, serum?
Test ID: SCL70 Scl 70 Antibodies, IgG, Serum 1 Useful For. Testing for Scl 70 antibodies is not useful in patients without demonstrable antinuclear… 2 Testing Algorithm. See Connective Tissue Disease Cascade (CTDC) in Special Instructions. 3 Clinical Information. Scl 70 (topoisomerase 1) is a 100-kD nuclear and nucleolar enzyme.
Are there any other diseases associated with Scl-70?
The antibodies are very specific to scleroderma and are very rarely present with other diseases or disorders. There are no known published cases of SCL-70 antibodies being associated with other conditions. A medical provider will typically interview a patient with suspected scleroderma to discuss their physical symptoms.
What happens when the SCL-70 blood test is negative?
If there are more CREST symptoms being experienced, there is a better chance that scleroderma may be present. When the symptoms of scleroderma are present, the SCL-70 test is negative, but the ACA blood test is positive, then a different autoimmune disorder may be affecting the body.