What is anti-SM blood test?

Anti-Sm (anti-Smith, named for the first patient known to have this antibody) is associated with a speckled ANA pattern and is the antibody seen in most patients who do not have anti-dsDNA. Some patients have both anti-dsDNA and anti-Sm. Anti-Sm antibody binds to a protein that is attached to DNA.

What is a positive anti-Sm test?

A positive result for anti-Sm antibodies is consistent with a diagnosis of lupus erythematosus.

What does anti Smith antibodies mean?

Description. Anti-Smith antibodies are present in some cases of systemic lupus erythematosus (SLE) and mixed connective-tissue disease (MCTD). Smith antigens are part of the extractable nuclear antigens (ENAs); specifically, they are the proteins that are resistant to ribonuclease.

What does SM test for?

Sm and Sm/RNP Antibodies – Antibodies to Sm are highly specific for systemic lupus erythematosus (SLE) and when present are considered a marker antibody. However, these antibodies are found in only 20% of patients with SLE.

How is an anti-Sm antibody test performed?

Anti-Sm antibody test is one of the blood tests in the ANA panel. Also, it is one of the tests performed after an initial screening test to confirm the diagnosis of systemic lupus. Why is an Anti-Sm Antibody test performed? How do you prepare for Anti-Sm Antibody test? How is an Anti-Sm Antibody test performed?

Where are Sm antibodies found in Le patients?

The levels of Sm antibodies remain relatively constant over time in patients with LE and are usually found in patients that also have RNP (ribonucleoprotein) antibodies. (1,2) Sm is 1 of 4 autoantigens commonly referred to as extractable nuclear antigens (ENA). The other ENA are RNP, SS-A/Ro, and SS-B/La.

Are there any anti Sm antibodies for SLE?

Anti-Sm antibodies offer a highly specific but relatively insensitive clinical marker of SLE. Their overall prevalence ranges from approximately 20-30% in SLE. Anti-Sm reactivity is not described definitively on other diseases, although a few studies describe Sm antibodies in monoclonal gammopathies and uveitis.

What is a smooth muscle antibody ( SMA ) test?

What is a smooth muscle antibody (SMA) test? This test looks for smooth muscle antibodies (SMAs) in the blood. A smooth muscle antibody (SMA) is a type of antibody known as an autoantibody. Normally, your immune system makes antibodies to attack foreign substances like viruses and bacteria.