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