Antinuclear antibodies and their detection methods in diagnosis of connective tissue diseases: a journey revisited

Connective tissue diseases (CTD) are a group of autoimmune disorders which are characterized by presence of antinuclear antibodies (ANA) in the blood of patients. ANA are a specific class of autoantibodies that have the capability of binding and destroying certain structures within the nucleus of the cells [1]. Although lower amounts of these antibodies can be seen in the normal population as well, a spurt in titers is seen in patients of CTD. Not only are these antibodies involved in the disease pathogenesis, but they also constitute the basis for diagnosis and treatment of CTD. Their detection with high sensitivity and specificity is therefore of utmost importance. Various detection methods are in use and there is continuous pouring of newer techniques to facilitate diagnosis and therapeutic monitoring in CTD patients. In this review we have discussed in brief how ANA were discovered and found to be associated with CTD. This article also gives an overview on advancement in various ANA detection methods, their future prospects along with advantages, disadvantages and guidelines for use of these tests.In 1941, Klemperer, Pollack and Baehr first described systemic lupus erythematosus (SLE) as one of the CTD [2]. Then in 1948 Malcom Hargrave, Helen Richmond and the medical resident Robert Morton noted the presence of previously unknown cells in the bone marrow of a patient with SLE. They called these LE cells and described them as mature polymorphonuclear leukocytes which had phagocytosed the liberated nuclear material of another leukocyte [3]. This extremely important discovery laid the foundation of research for ANA. Since then, ANA has been divided into specific subtypes based on the nuclear or cytoplasmic component they attack i.e. anti-DNA, anti-histone etc.Presently the ANA have been categorized in to 2 main groups:These include antibodies against single and double-stranded DNA (dsDNA) discovered way back in 1957. Significant levels of anti-dsDNA antibodies are