Types of Ana
The many known subtypes of ANA can be grouped in 2 main categories, namely, autoantibodies against DNA and histones, and autoantibodies against extractable nuclear antigens (ENAs). The first group includes antibodies against dsDNA (double-stranded DNA) and against histones. Antibodies against dsDNA in high titers are considered to confirm SLE diagnosis. Antibodies against histones indicate drug-induced SLE. The second group includes antibodies against Smith antigen (Sm), wich are specific for SLE, anti–SS-A/Ro, and anti–SS-B/La (these 2 types are specific for Sjögren syndrome, subacute cutaneous SLE, and neonatal lupus syndrome), anticentromere (considered specific for limited cutaneous SS), Jo-1 (considered specific for PM), anti–U3-RNP, and Scl-70 (these final 2 are considered specific for SS). In recent years, more antigens attacked by ANA, such as topoisomerase-I, centromere protein B, and RNA-polymerase I-III, have been described in the literature.[4–7] Even if most of them are disease specific, a statistically significant overlap still exists.
Lab Med. 2018;49(3):e62-e73. © 2018 American Society for Clinical Pathology