Anti-Sm antibody positivity

What it means

The presence of autoantibodies in the serum that react to seven proteins that consist of a core of small nuclear ribonucleoprotein (snRNP) particles.

Anti-Sm-autoantibodies are highly specific for systemic lupus erythematosus (SLE).

Rare diseases that can present with this2

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions, and Orphanet separately records 1 disease where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Anti-Smith autoantibody