Anti-double stranded DNA antibody (anti-dsDNA) is one of a group of autoantibodies called antinuclear antibodies (ANA). Normally, antibodies protect against infection, but autoantibodies are produced when a person’s immune system fails to adequately distinguish between “self” and “non-self.” They mistakenly attack the body’s own healthy cells, causing tissue and organ damage. Anti-dsDNA specifically targets the genetic material (DNA) found in the nucleus of a cell, hence the name “anti-dsDNA.” The anti-dsDNA test identifies the presence of these autoantibodies in the blood. This test helps diagnose and monitor lupus, a chronic, inflammatory autoimmune disorder. Sample: Blood (serum) Reference: Less than 20 U/ml Frequency: Twice week