Anti Sm Antibody

Test/Profile Name

Anti Sm Antibody

Test/Profile Code


Clinical Usefullness

Sm (Smith) is a small nuclear ribonucleoprotein composed of several protein autoantigens designated B, B1, D, E, F, and G, which range in size from 11 kD to 26 kD. Anti-Smith antibody has low sensitivity but high specificity for Systemic Lupus Erythematosus (SLE). Anti-Smith antibody levels are elevated in 30% of SLE cases and 8% of Mixed Connective Tissue Disease (MCTD) cases. Anti-Smith antibody is more common in Africans and Asians with SLE than in whites with SLE. The levels of Sm antibodies remain relatively constant over time in patients with SLE and are usually found in patients that also have RNP (ribonucleoprotein) antibodies.

Specimen Type and Minimal Volume

Variable Please confirm with the laboratory prior to testing.

Include Test