RT Journal
A1 Hydovitz JD, Lippe RD, Melada GA
T1 TRiiodothyronine levels
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 1979
FD November 1
VO 139
IS 11
SP 1319
OP 1320
DO 10.1001/archinte.1979.03630480091041
UL http://dx.doi.org/10.1001/archinte.1979.03630480091041
AB To the Editor.— 
    The "isolated high serum triiodothyronine levels" discussed in the article by Soler et al in the Archives (139:36-38, 1979) represent the type of data that occasionally generates uncertainty in the interpretation of thyroid function studies in patients with or without clinical manifestations of thyroid disease.While the radioimmunoassay techniques used in the measurement of triiodothyronine (T3) do supply information that is reliable and reproducible in most instances, procedural problems can result in erroneous values that are entirely discordant with the patient's clinical status. In this setting, it would be most appropriate to repeat the determinations for verification before embarking on some additional diagnostic maneuver or plotting a course of therapy.Serum free thyroxine index units, the measurement used in the study reported by Soler et al, do not contribute any indirect information in regard to the concentrations of thyroxine binding proteins. Consequently, the serum total T