title: [Determination of free L-triiodothyronine (FT3) in serum. Comparative tests of 2 FT3 radioimmunoassays].
abstract: A trial of the routine use of two test procedures for the evaluation of free L-triiodothyronine (FT3) was carried out (1070 patients). The normal values given by the manufacturers are not correct with respect to our patient group. In order to avoid false hyperthyroid (FT3-Amerlex) or false hypothyroid (FT3-DPC) values, the normal spectrum was redetermined for each. Under these conditions, both tests could show a definite difference between normal and overfunctioning of the thyroid. In substitution therapy with L-thyroxine, the quality of adjustment may be assessed according to the FT3 value. An extension of the normal spectrum, as for FT4, is not necessary. Since any additional assessment of the carrier protein concentration becomes irrelevant, the FT3 test is advisable also for economic reasons.
mesh_terms: D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis; D011863:Radioimmunoassay; D012016:Reference Values; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine
vernacular_title: Die Bestimmung des freien L-Trijodthyronins (FT3) im Serum. Ein Testvergleich zweier FT3-Radioimmunoassays.