ITEMS IN AFP WITH MESH TERM:
ABSTRACT: Serum rheumatologic tests are generally most useful for confirming a clinically suspected diagnosis. Testing for rheumatoid factor is appropriate when rheumatoid arthritis, SjÃ¶gren's syndrome or cryoglobulinemia is suspected. Antinuclear antibody testing is highly sensitive for systemic lupus erythematosus and drug-induced lupus. Anti-double-stranded DNA antibodies correlate with lupus nephritis; the titer often corresponds with disease activity in systemic lupus erythematosus. Testing for anti-Ro (anti-SS-A) or anti-La (anti-SS-B) may help confirm the diagnosis of SjÃ¶gren's syndrome or systemic lupus erythematosus; these antibodies are associated with the extraglandular manifestations of SjÃ¶gren's syndrome. Cytoplasmic antineutrophil cytoplasmic antibody testing is highly sensitive and specific for Wegener's granulomatosis. Human leukocyte antigen-B27 is frequently present in ankylosing spondylitis and Reiter's syndrome, but the background presence of this antibody in white populations limits the value of testing. An elevated erythrocyte sedimentation rate (ESR) is a diagnostic criterion for polymyalgia rheumatica and temporal arteritis; however, specificity is quite low. ESR values tend to correlate with disease activity in rheumatoid arthritis and may be useful for monitoring therapeutic response.
ABSTRACT: Systemic lupus erythematosus is a multisystem inflammatory disease that is often difficult to diagnose. Before the diagnosis can be established, four of 11 clinical and laboratory criteria must be met. Antinuclear antibody titer is the primary laboratory test used to diagnose systemic lupus erythematosus. Because of the low prevalence of the disease in primary care populations, the antinuclear antibody titer has a low predictive value in patients without typical clinical symptoms. Therefore, as specified by the American College of Rheumatology, this titer should be obtained only in patients with unexplained involvement of two or more organ systems. Patients with an antinuclear antibody titer of 1:40 and characteristic multiorgan system involvement can be diagnosed with systemic lupus erythematosus without additional testing; however, patients with an antibody titer of 1:40 who fail to meet full clinical criteria should undergo additional testing, including tests for antibody to double-stranded DNA antigen and antibody to Sm nuclear antigen. While an antinuclear antibody titer of less than 1:40 usually rules out systemic lupus erythematosus, patients with persistent, characteristic multisystem involvement may be evaluated for possible antinuclear antibody-negative disease.
Antibody Testing for Systemic Lupus Erythematosus - FPIN's Clinical Inquiries