Which tests measure Anti-Smith Antibody?

Anti-Smith Antibody is measured in 1 test on BiomarkersLabs.com, including ANA 11 Components (No ANA Screen).

Biomarker Reference · Anti-Sm

What does the Anti-Smith Antibody test measure?

Q: Why is Anti-Smith Antibody measured?

Anti-Sm carries approximately 99% specificity for SLE, making it the most diagnostically specific component in the panel, though sensitivity is low at 20–30%. A positive result is diagnostically significant regardless of titre level and supports SLE classification per EULAR/ACR criteria. Anti-Sm does not correlate with disease activity and is not used for monitoring.

Q: What is the reference range for Anti-Smith Antibody?

The standard reference range for Anti-Smith Antibody is <1.0 AI (negative); ≥1.0 AI (positive) # REVIEWER FLAG: Confirm reporting format and cut-off with Access Med Labs — some platforms report as AI, others qualitatively as positive/negative, and some in units/mL.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Anti-Smith Antibody (Anti-Sm) is a clinical biomarker used in autoimmune-inflammation assessment. Smith antibodies target the B, B', D, E, F, and G polypeptide components of snRNP (small nuclear ribonucleoprotein) complexes within the spliceosome, typically arising through epitope spreading from an initial U1-RNP response. It is measured in 1 laboratory test on BiomarkersLabs.com.

Reference Range: <1.0 AI (negative); ≥1.0 AI (positive) # REVIEWER FLAG: Confirm reporting format and cut-off with Access Med Labs — some platforms report as AI, others qualitatively as positive/negative, and some in units/mL.
Units: AI (antibody index)
Measured In: 1 test
Category: Autoimmune

Functional medicine optimalNegative — a positive result is highly specific for SLE; titre level has no functional medicine grading.

What is Anti-Smith Antibody?

Smith antibodies target the B, B', D, E, F, and G polypeptide components of snRNP (small nuclear ribonucleoprotein) complexes within the spliceosome, typically arising through epitope spreading from an initial U1-RNP response. Once established, anti-Sm titres remain stable regardless of disease activity.

Why is Anti-Smith Antibody measured?

Anti-Sm carries approximately 99% specificity for SLE, making it the most diagnostically specific component in the panel, though sensitivity is low at 20–30%. A positive result is diagnostically significant regardless of titre level and supports SLE classification per EULAR/ACR criteria. Anti-Sm does not correlate with disease activity and is not used for monitoring.

Reference ranges

Standard reference: <1.0 AI (negative); ≥1.0 AI (positive) # REVIEWER FLAG: Confirm reporting format and cut-off with Access Med Labs — some platforms report as AI, others qualitatively as positive/negative, and some in units/mL.
Functional medicine optimal: Negative — a positive result is highly specific for SLE; titre level has no functional medicine grading.
Units: AI (antibody index)

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.

Tests that measure Anti-Smith Antibody

1 test on BiomarkersLabs.com include this biomarker.

BML-AUT-001Comprehensive

ANA 11 Components (No ANA Screen)

Anti-Smith Antibody reference range in this test: <1.0 AI (negative); ≥1.0 AI (positive) # REVIEWER FLAG: Confirm reporting format and cut-off with Access Med Labs — some platforms report as AI, others qualitatively as positive/negative, and some in units/mL.

Related clinical conditions

Related Biomarkers

Frequently measured alongside

Anti-Double-Stranded DNA Antibody (IgG)Anti-dsDNA IgG1 test Anti-U1 Ribonucleoprotein AntibodyAnti-RNP1 test Anti-SSA/Ro 60 kDa AntibodyAnti-Ro601 test Anti-SSA/Ro 52 kDa Antibody (TRIM21)Anti-Ro521 test Anti-SSB/La AntibodyAnti-La1 test Anti-Scl-70 (Topoisomerase I) AntibodyAnti-Scl-701 test Anti-Jo-1 (Histidyl-tRNA Synthetase) AntibodyAnti-Jo-11 test Anti-Centromere B AntibodyAnti-CENP-B1 test

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