Anti-Sm antibodies, sometimes referred to as anti-Smith antibodies, are produced by the immune system and directed against the body's own proteins. They play a major role in several autoimmune diseases, and tests for the presence of these antibodies are commonly used as diagnostic indicators for a number of different conditions.
Discovery
Anti-smith antibodies were first discovered in the 1960s, after doctors treating a young woman named Stephanie Smith for systemic lupus erythematosus discovered that her body was manufacturing a unique set of antibodies to certain nuclear proteins. This set of nuclear proteins thus became known as the Smith Antigen, and the antibodies produced in response to it were known as anti-Smith antibodies. In modern clinical practice, the name is usually shortened to "anti-Sm" antibodies.
Applications
Testing for the presence of anti-Sm antibodies is typically used to aid in the diagnosis of different varieties of Lupus, an autoimmune disease that causes the immune system to attack the body's own tissue. The presence of these antibodies is always an indication of Lupus, although it is possible to for the body to contract Lupus without producing them. Anti-Sm antibodies are also used as an indicator for central nervous system and liver involvement in the treatment of Lupus.
Mechanism of Action
Anti-Sm immune responses involve multiple sets of antibodies binding to multiple sets of antigens. These antibodies bind to a specific antigen consisting of a set of proteins and RNAs called small nuclear ribonucleoprotein particles, or snRNPs, in cell nuclei. These snRNPs play an important role in the splicing of messenger RNA, one of the steps involved in RNA transcription. Anti-Sm antibodies can be found more frequently in African American and Asian patients than in Caucasians.
New Developments
Research spurred by the discovery of anti-Sm antibodies and the Smith Antigen has been ongoing since the 1960s. This has led to the identification of an entire protein family, LSm proteins, and spurred research into a variety of others. Scientists have modeled the folding action of these proteins and produced detailed models of their structure and function. This has led to a greater understanding of the role of RNA in the body --- knowledge with application to a number of different fields.
Tags: antibodies produced, anti-Sm antibodies, Anti-Sm antibodies, anti-Smith antibodies, immune system