The technology
Analytical systems for detecting and measuring autoantibodies
have evolved significantly in the last 20 years,
encompassing three progressive generations of different
analytical immunoreactions and achieving the predictions
made at the beginning of the 1990s that the most important
factors influencing changes in the clinical immunology laboratory
would be governmental regulations as related to
restrictions on healthcare funding, advances in technology and
advances in the treatment of autoimmune diseases (AIDs) [1].
As recently outlined [2], most of these predictions have
come true, especially the evolution in the role and importance
of autoantibodies in the diagnosis and therapy of
AIDs, the tremendous evolution of immunoassays and of
analytical instruments and the consolidation of autoimmunology
as a subspecialty in clinical laboratories.
The progressive increase in requests for autoantibody tests
that has occurred in recent years (Fig. 1) has brought about
the introduction of near-total and total automation in the
clinical immunology laboratory [3–5]. Two main categories
of methods (immunochemical for antibody detection and
immunometric for antibody quantification) have found
application in the diagnosis of AIDs. Besides indirect
immunofluorescence (IIF) which maintains its basic role in
autoimmune diagnostics, a wide number of different immunoassays
(monoplex and multiplex) are currently used for
single or multiple measurements of autoantibodies [6, 7]. A
tentative classification of these methods is shown in Table