Lupus Site - a guide for lupus patients and their families

Anti-Sm is an immunoglobulin specific against Sm, a ribonucleoprotein found in the cell nucleus.

Rare in UK; mainly found in West Indians with SLE. Not found in any other diseases, only in SLE. However, only 30% of patients with SLE have a positive anti-Sm test.

A positive test means - A positive test usually means that lupus is present.

A negative test means - Does not mean that lupus is not present. Most people with lupus have either anti-DNA or anti-Sm antibodies.