WHAT IS AN AUTOANTIBODY

ABSTRACT Since their initial description in association with autoimmune disease, autoantibodies have been defined as an aberration of an essentially physiological and protective process, representing immunoglobulins reacting against self-molecules. Although contradicting the historically postulated mechanisms of immune tolerance, especially when directed against ontogenically conserved molecules, their detection in virtually all autoimmune diseases has established an undisputed diagnostic value. Nonetheless, the essence of their generation and perpetuation remains obscure, as their potential role in disease initiation maintaining exciting areas for future research. Finally, we note that there are considerably more autoantibodies than there are autoimmune diseases. The recognition that self-reactivity may not be synonymous of disease is an important concept that likewise requires further study.