Smith (ENA) Antibody, IgG
Also known as: SMITH
Use
Smith antibodies are highly specific for systemic lupus erythematosus (SLE), appearing in 30-35% of SLE cases. Although highly specific, the presence of Smith antibodies has variable associations with clinical manifestations of SLE, making this test an important confirmatory diagnostic tool when antinuclear antibodies (ANA) are present.
Special Instructions
This test is New York state approved and should be used as a confirmatory assay in cases where systemic lupus erythematosus (SLE) is suspected based on ANA results.
Limitations
The Smith (ENA) Antibody test can only be performed on serum samples, as plasma and other body fluids are unsuitable. Contaminated, hemolyzed, or severely lipemic specimens are also unacceptable. The test specifically detects Smith antibodies, which are found in about 30-35% of SLE cases, and their presence correlates variably with SLE manifestations.
New York Approved
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
LOINC Codes
- 18323-6
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Separate serum from cells as soon as possible or within 2 hours of collection.
Storage Instructions
Refrigerate the sample for transport.
Causes for Rejection
Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 year (avoid repeated freeze/thaw cycles) |
Other tests from different labs that may be relevant