Antibody Tests for Lupus

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Topic Overview

Antibody tests are a set of blood tests that check for specific antibodies to help clarify the diagnosis of lupus. They include:

  • Anti-dsDNA (antibodies to DNA).
  • Antinuclear antibody (ANA)
  • Anti-RNP.
  • Anti-Smith (Sm).
  • Anti-SS-A (also called Ro).
  • Anti-SS-B (also called La).

These antibody tests are often positive in lupus and can provide support for a diagnosis if the clinical criteria are unclear or if the ANA test is negative but lupus is strongly suspected.

  • Anti-SS-A (Ro) and anti-SS-B (La) antibodies are not specific for lupus and are found commonly in Sjögren's syndrome. But these tests are useful in helping women with lupus who are considering pregnancy. If a woman who has these antibodies becomes pregnant, she may need more careful monitoring of the fetus, since these antibodies are associated with a higher risk of the baby being born with neonatal lupus syndrome or a heart defect called congenital heart block.
  • High titers of anti-dsDNA are usually seen only in people who have lupus.
  • A positive anti-Sm test is a specific marker for lupus.

Anti-dsDNA tests can be repeated at intervals to monitor how the disease is progressing.

References

Other Works Consulted

  • Crow MK (2012). Systemic lupus erythematosus. In L Goldman, A Schafer, eds., Goldman's Cecil Medicine, 24th ed., pp. 1697–1705. Philadelphia: Saunders.
  • Hahn BH (2012). Systemic lupus erythematosus. In DL Longo et al., eds., Harrison's Principles of Internal Medicine, 18th ed., vol. 2, pp. 2724–2735. New York: McGraw-Hill Medical.

Credits

ByHealthwise Staff
Primary Medical ReviewerAnne C. Poinier, MD - Internal Medicine
Specialist Medical ReviewerNancy Ann Shadick, MD, MPH - Internal Medicine, Rheumatology

Current as ofSeptember 9, 2014