Confirmatory test for systemic lupus erythematosus (SLE) based on ANA results.
Semi-Quantitative Multiplex Bead Assay
Serum separator tube.
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
|29 AU/mL or less||Negative|
|41 AU/mL or greater||Positive|
Smith antibody is highly specific (greater than 90 percent) for systemic lupus erythematosus (SLE) but only occurs in 30-35 percent of SLE cases. The presence of antibodies to Smith has variable associations with SLE clinical manifestations.
|Component Test Code*||Component Chart Name||LOINC|
|0050085||Smith (ENA) Antibody, IgG||18323-6|
- Anti-Smith (ENA) Antibody
- Sm antibody IgG