|
|
||||||||
Clinical Chemistry, Vol 33, 87-92, Copyright © 1987 by American Association for Clinical Chemistry
G Csako, MH Zweig, C Benson and M Ruddel
We studied the relation between thyroxin-binding proteins and free thyroxin (FT4) measurements by five radioimmunoassays (RIA) and an FT4 index (FT4I) in patients with non-thyroidal illness (NTI). The one-step FT4 RIAs and the FT4I frequently failed to identify the true FT4 status (as determined by equilibrium dialysis) of NTI patients. In these patients, falsely low FT4 results with one-step RIAs and FT4I were associated with decreasing total T3 and T4 concentrations, which, furthermore, paralleled decreasing serum albumin concentrations. All NTI patients with "low T3, low T4 syndrome" had subnormal albumin concentration. The two-step RIAs and equilibrium dialysis showed normal FT4 concentrations in most patients with NTI. However, sera from a subset of NTI patients with "low T3 syndrome" gave above-normal FT4 results with these methods. From their predictably poor performance in the presence of a subnormal albumin concentration, we conclude that the one-step FT4 RIAs and FT4I are inappropriate for testing the thyrometabolic status of NTI patients.
The following articles in journals at HighWire Press have cited this article:
![]() |
K. S. Fritz, R. B. Wilcox, and J. C. Nelson A Direct Free Thyroxine (T4) Immunoassay with the Characteristics of a Total T4 Immunoassay Clin. Chem., May 1, 2007; 53(5): 911 - 915. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Yonemura, T. Nakajima, T. Suzuki, S. Ando, R. Genma, H. Nakamura, and A. Hishida Low free thyroxine concentratios and deficient nocturnal surge of thyroid-stimulating hormone in haemodialysed patients compared with undialysed patients Nephrol. Dial. Transplant., May 1, 2000; 15(5): 668 - 672. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. D. Christofides, E. Wilkinson, M. Stoddart, D. C. Ray, and G. J. Beckett Assessment of Serum Thyroxine Binding Capacity-dependent Biases in Free Thyroxine Assays Clin. Chem., April 1, 1999; 45(4): 520 - 525. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. J. De Groot Dangerous Dogmas in Medicine: The Nonthyroidal Illness Syndrome J. Clin. Endocrinol. Metab., January 1, 1999; 84(1): 151 - 164. [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |