Autoantibody diagnostics in clinical practice.

Disease associated autoantibodies (AAB) are important biomarkers not only to confirm the diagnosis of the respective systemic autoimmune disease but also to diagnose the disease at very early stages (mono- or oligosymptomatic manifestations) or to diagnose the respective disease without the typical clinical manifestations (atypical forms). A confirmation of the diagnosis in early stages is required, if patients should benefit from early therapeutic intervention. Furthermore, AAB determinations are used for prognostic purposes and for monitoring of disease activity or response to therapy. For the advancement of autoantibody diagnostics in clinical practice the following aspects have to be considered: (i) The search for novel clinically relevant AAB and the identification of autoantigenic targets of AAB broadened the spectrum of autoimmune diagnostics and permit the diagnosis of former idiopathic diseases. (ii) To obtain steady diagnostic variables of clinically relevant AAB, the evaluation studies have to be standardized. (iii) Several special features and novel developments of autoantibody diagnostics make correct interpretation of antibody test results increasingly difficult. (iv) Beside standardization of AAB detection methods and quality management efforts the improvement of autoantibody diagnostics depends on further development of diagnostic algorithms including cost-effective multiparametric analyses.