Biomaterial Database

Improved dialysis method for free thyroxin in serum compared with five commercial radioimmunoassays in nonthyroidal illness and subjects with abnormal concentrations of thyroxin-binding globulin. 1983

T Helenius, and K Liewendahl

We describe a method for free thyroxin (FT4) in serum, based on radioimmunoassay of T4 in serum dialysate, FT4(D). The method is analytically accurate, sensitive, reproducible, and suitable for routine use in the clinical laboratory. We compared results by this method with those obtained with five commercial FT4 assays (Amerlex, GammaCoat, ImmoPhase, LiquiSol, Spiria) and the free T4 index (FT4I). In several of the patients with nonthyroidal illness FT4(D) was above normal and FT4 as measured with the commercial assays was subnormal. In the third trimester of pregnancy all the FT4 methods gave decreased mean values, though the decreases were of various magnitudes: FT4(D) 32%, Amerlex 44%, GammaCoat 40%, Spiria 19%, LiquiSol 16%, and ImmoPhase 13%, respectively. FT4I was significantly higher than normal during late pregnancy. In women taking oral contraceptives the mean FT4I was increased, but there was no significant effect on the results obtained with the various FT4 methods. All subjects with hereditarily high or low serum thyroxin-binding globulin had normal FT4(D) and abnormal FT4I. Amerlex, ImmoPhase, and LiquiSol misclassified some of the subjects with hereditarily abnormal thyroxin-binding globulin.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008659	Metabolic Diseases	Generic term for diseases caused by an abnormal metabolic process. It can be congenital due to inherited enzyme abnormality (METABOLISM, INBORN ERRORS) or acquired due to disease of an endocrine organ or failure of a metabolically important organ such as the liver. (Stedman, 26th ed)	Thesaurismosis,Diseases, Metabolic,Disease, Metabolic,Metabolic Disease,Thesaurismoses
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011263	Pregnancy Trimester, Third	The last third of a human PREGNANCY, from the beginning of the 29th through the 42nd completed week (197 to 294 days) of gestation.	Pregnancy, Third Trimester,Trimester, Third,Last Trimester,Last Trimesters,Pregnancies, Third Trimester,Pregnancy Trimesters, Third,Third Pregnancy Trimester,Third Pregnancy Trimesters,Third Trimester,Third Trimester Pregnancies,Third Trimester Pregnancy,Third Trimesters,Trimester, Last,Trimesters, Last,Trimesters, Third
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D003956	Dialysis	A process of selective diffusion through a membrane. It is usually used to separate low-molecular-weight solutes which diffuse through the membrane from the colloidal and high-molecular-weight solutes which do not. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Dialyses
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults