Systemic Lupus Erythematosus - Treatment

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A negative ANA test makes a diagnosis of SLE unlikely but not impossible. High or low concentrations of ANA also do not necessarily indicate the severity of the disease, since antibodies tend to come and go in patients with SLE.

In general, the ANA test is considered a screening test:

• If SLE-like symptoms are present and the ANA test is positive, other tests for SLE will be administered.
• If SLE-like symptoms are not present and the test is positive, the doctor will look for other causes, or the results will be ignored if the patient is feeling healthy.

ANA Subtypes. Doctors may also test for specific ANA subtypes.

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• Anti-double stranded DNA (Anti-ds DNA) is more likely to be found only in patients with SLE. It may play an important role in injury to blood vessels found in SLE, and high levels often indicate kidney involvement. Anti-ds DNA levels tend to fluctuate over time and may even disappear.
• Anti-Sm antibodies are also usually found only with SLE. Levels are more constant and are more likely to be detected in African-American patients. Although many lupus patients may not have this antibody, its presence almost always indicates SLE.
• When the ANA is negative but the diagnosis is still strongly suspected, a test for anti-Ro (also called anti-SSA) and anti-La (also called anti-SSB) antibodies may identify patients with a rare condition called ANA negative, Ro lupus. These autoantibodies may be involved in the sun-sensitive rashes experienced by patients with SLE and are also found in association with neonatal lupus syndrome, in which a pregnant mother's antibodies cross the placenta and cause inflammation in the developing child's skin or heart.

Antiphospholipid Antibodies. Up to half of patients with SLE have antiphospholipid antibodies, which increase the risk for blood clots, strokes, and pregnancy complications. If a doctors suspects someone with SLE has blood abnormalities, tests may be able to detect the presence of the two major antiphospholipid antibodies: lupus coagulant antibody and anticardioplin antibody.