Ordering Recommendation

Confirmatory test for systemic lupus erythematosus (SLE) based on ANA results.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube.

Specimen Preparation

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)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Methodology

Semi-Quantitative Multiplex Bead Assay

Performed

Sun-Sat

Reported

1-3 days

Reference Interval

Test Number
Components
Reference Interval
  Smith (ENA) Antibody, IgG 40 AU/mL or less

Interpretive Data

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
Interpretation
Smith (ENA) Antibody, IgG 29 AU/mL or less           Negative
30-40 AU/mL                 Equivocal
41 AU/mL or greater     Positive

Compliance Category

FDA

Note

Hotline History

N/A

CPT Codes

86235

Components

Component Test Code* Component Chart Name LOINC
0050085 Smith (ENA) Antibody, IgG 18323-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Anti-Sm
  • Anti-Smith (ENA) Antibody
  • Sm antibody IgG
  • Sm/RNP
Smith (ENA) Antibody, IgG