ARUP's Laboratory Test Directory

0050085: Smith (ENA) Antibody, IgG

Test Mnemonic: SMITH
Methodology: Multi-Analyte Fluorescent Detection

Performed: Sun-Sat

Reported: 1-2 days

Specimen Required:  
Collect: One 4 mL SST.

Transport: 1 mL serum at 2-8°C. (Min: 0.5 mL)  Submit specimen in an ARUP Standard Transport Tube.

Pediatric Collection/Transport: 0.15 mL serum at 2-8°C.

Remarks: Separate serum from cells ASAP.

Unacceptable Conditions: Plasma and other body fluids.  Severely lipemic, contaminated, and hemolyzed specimens.

Stability: After separation from cells: Ambient: 2 days; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval:
29 AU/mL or less: Negative
30-40 AU/mL: Equivocal
41 AU/mL or greater: Positive

Interpretive Data:
Smith antibody is very specific for systemic lupus erythematosus (SLE) but only occurs in 30-35% of SLE cases.  The presence of antibodies to Smith is often associated with renal disease.



CPT Code(s):
86235

 

 

 
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