Analytical and clinical performance goals for testing autoantibodies to thyroperoxidase, thyroglobulin, and thyrotropin receptor

Methods for measuring thyroid autoantibodies--to thyroperoxidase (TPOAb), thyroglobulin (TgAb), and thyrotropin receptor (TRAb)--have improved over the last decade, but increasingly, accurate and sensitive methods are needed for identifying patients with autoimmune thyroid diseases and individuals at high risk for onset of thyroid autoimmunity. With the increased quality requirements for these methods, it becomes more important to look at the functional sensitivities and precision profiles of the various methods. International standardization in this field is also needed. Because most sera containing human thyroid autoantibodies display a variety of antigen-specific immunoglobulins of different classes and subclasses with different affinity and avidity in their epitope reaction, investigators must decide whether the autoantibodies should be quantified in terms of immunoglobulin content, antigen/epitope reactivity, or binding capacity. Until these problems are solved, the best means for standardization are the Medical Research Council calibrators for TPOAb and TgAb, whereas no standardization exists for TRAb.