[Current topics on immunological laboratory tests-thyroid diseases]

Current topics in the field of thyroid disease are the development of the second generation assay for TSH receptor antibody (TRAb) using recombinant human TSH receptor and the appearance of antineutrophil cytoplasmic antibodies(ANCA) in Graves' disease patients treated with propylthiouracil(PTU). This new TRAb assay is very useful, since the sensitivity and the specificity were almost 100%, respectively, in the diagnosis of Graves' disease. Furthermore, a new coated tube assay for the detection of blocking TRAb has been developed by using TSH/LH receptor chimera. The prevalence of ANCA is high in Graves' disease patients treated with PTU, but the clinical significance of ANCA is under controversy, since only a part of them develop vasculitis, and recently it has been reported that ANCA is frequently positive in Graves' disease patients before the onset of methimazole treatment. The 7th version of guidelines for the diagnosis of thyroid disease have been prepared by the Japan Thyroid Association, and opens to public inspection. They show the importance of immunological laboratory tests in this field.