Anti-DNA antibodies are a subgroup of antinuclear antibodies detected by specific identification tests. These tests are essentially immuno-enzymatic, called ELISA (Enzyme Linked Immuno Sorbent Assay) and Farr test. The objective of these tests is to identify and quantify a developed autoimmune reaction against the DNA of chromosomes. This chromosomal DNA is called native, because it is really a "pure" DNA, composed by the famous double helix. The real markers of lupus are therefore the anti-native DNA antibodies, but not the anti-denatured DNA antibodies (which are formed by only one helix). Anti-denatured antibodies can be detected in many circumstances, pathological or non-pathological, and their search is not useful for diagnosing or treating lupus.

Anti-native DNA antibodies are very characteristic of lupus, but they are not present in all patients. These anti-native DNA antibodies are excellent diagnostic markers of lupus, present from the beginning of the disease. However, they are only detected in 60 to 70% of patients, in particular when the disease is active. In other words, you can suffer from genuine lupus without native DNA antibodies. In this case, you certainly have antinuclear antibodies directed against other structures of the nucleus (example: anti-Ro/SS-A and/or anti-La/SS-B), but it is also possible that anti- native DNA appear later, during the course of the disease.

Anti-native DNA antibodies can directly cause lupus damage, such as kidney damage. Their rate varies with the activity of the disease. These anti-native DNA antibodies also have a pathogenic role, because by settling in the kidney of patients, they cause glomerular nephropathy.

The more active your disease, the higher levels of anti-native DNA antibodies will be found in the blood. So if you have lupus with anti-native DNA, your doctor will use this test to track the course of your disease.