Abstract
FT4-measurement as a routine method is established in newborns recalled for a 2nd blood sample by thyroid screening. Since the kinetic FT4-assay(A) has been widely discussed for its potentially misleading results in adults the results of A are compared with 3 analogue methods(B,C,D). In addition TT4,TT3 and FT3 values are compared in 149 children of different age: group I: first 2 months;group II:3rd to 24th month;group III: 3rd to 8th year of life.
RESULTS: FT4,TT4,FT3 and TT3 values of method A were significantly higher(p 0.001) than of the methods B,C,D in all 3 groups. Mean FT4 and FT3 values of all 4 methods showed less variations than TT4 and TT3 values. There was a 20-30% decline in FT4 between I and III in A,B and D but not in C.Whereas FT4 values of all methods correspond by means of a decline with increasing age,FT3 values were not corresponding with each other neither refering to method nor to age group.
CONCLUSIONS: All 4 methods performed well and were statistically identical with respect to their diagnosis in children up to 8 years. The differences between the methods may play a more important role in severely sick children or in adolescents.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Klett, M., Zeising, S., Hieronymus, K. et al. 79 FREE THYROXINE(FT4) AND FREE TRIJ0D0THYR0NINE(FT3) IN CHILDREN: COMPARISON OF FOUR DIFFERENT METHODS. Pediatr Res 19, 616 (1985). https://doi.org/10.1203/00006450-198506000-00099
Issue Date:
DOI: https://doi.org/10.1203/00006450-198506000-00099