SLE (Systemic Lupus Erythematosus) is an autoimmune connective tissue disease, similar to systemic sclerosis, RA, and mixed connective tissue disease. Often, symptoms of these diseases overlap. In cases where you unable to distinguish exactly which condition is present,we would normally say that mixed connective tissue disease is present. Like those other disorders, ANA’s (anti-nuclear antibodies) can be found in blood of many affected patients.
Antibodies form in the body as a response to infection. When an invader (antigen) enters the body, white blood cells known as B lymphocytes react by making special types of proteins called antibodies. Antibodies are your body’s way of remembering an antigen; if it enters the body again, the antibodies will recognize it, combine with it, and neutralize it to prevent you from becoming infected. However, with autoimmune diseases such as lupus, the immune system can produce antibodies (auto-antibodies) that attack your body’s cells as though they were invaders, causing inflammation, damage, and even destruction. Several blood tests can be performed to detect specific auto-antibodies and help make the diagnosis of lupus. These blood tests are not conclusive by themselves, but combining the tests with certain physical findings can help to corroborate a diagnosis.