PhillyEBM.comThe ANA is of limited utility in screening for rheumatologic disease.
What is the utility of ordering an ANA when a patient is suspected of having rheumatologic disease?
• The ANA is of no use in making or excluding the diagnosis of juvenile rheumatoid arthritis (JRA). • A negative ANA is helpful to exclude the diagnosis of systemic lupus erythematousus (SLE). • A positive ANA can support the diagnosis of SLE, however given the low prevalence of SLE, most positive ANAs will not represent disease. • In patients presenting with Raynaud syndrome, a positive ANA is predictive of having an underlying rheumatologic disease.
• A meta-analysis revealed that the specificity of the ANA for JRA was only 39% and the sensitivity was only 57%.1 • In a more recent 2004 study ANA titers did not distingush between those patients with JRA versus non-inflammatory musculoskeletal pain.3 • Meta-analysis did show that a positive ANA did have a sensitivity of 93% for SLE. However given the low prevalence of SLE in the population its positive predictive value was only 11%. Its specificity was only 57%.1 • Many patients with a positive high titer ANA had no signs of autoimmune disease. Furthermore, children with positive ANA but no clinical signs of autoimmunity were not at greater risk for developing rheumatologic disease in the future.2,4 • In a series of 27 patients with Raynaud syndrome, 100% of patients with rheumatologic disease had a positive ANA, none of the patients without rheumatologic disease had a positive ANA.5
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1) Solomon DH, Kavanaugh AJ, Schur PH. Evidence-based guidelines for the use of immunologic tests: antinuclear antibody testing. Arthritis Rheum. 2002 Aug;47(4):434-44. [Penn Proxy]
2) Vaile JH, Dyke L, Kherani R, Johnston C, Higgins T, Russell AS. Is high titre ANA specific for connective tissue disease? Clin Exp Rheumatol. 2000 Jul-Aug;18(4):433-8. [Penn Proxy]
3) McGhee JL, Kickingbird LM, Jarvis JN. Clinical utility of antinuclear antibody tests in children. BMC Pediatr. 2004 Jul 9;4:13. [Penn Proxy]
4) Cabral DA, Petty RE, Fung M, Malleson PN. Persistent antinuclear antibodies in children without identifiable inflammatory rheumatic or autoimmune disease. Pediatrics. 1992 Mar;89(3):441-4. [Penn Proxy]
5) Duffy CM, Laxer RM, Lee P, Ramsay C, Fritzler M, Silverman ED. Raynaud syndrome in childhood. J Pediatr. 1989 Jan;114(1):73-8. [Penn Proxy]