Open AccessA highly sensitive sandwich enzyme immunoassay of human thyroid‐stimulating hormone in dried blood on filter paper discs for mass‐screening of neonatal hypothyroidism
Author(s) -
Hashida Seiichi,
Tanaka Koichiro,
Kohno Takeyuki,
Ishikawa Eiji,
Umehashi Hozo,
Hayashida Toshiyuki,
Mori Toru,
Imura Hiroo,
Ogawa Hiroshi
Publication year - 1987
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.1860010209
Subject(s) - immunoassay , human chorionic gonadotropin , enzyme , monoclonal antibody , thyroid stimulating hormone , endocrinology , medicine , reference range , conjugate , chemistry , chromatography , filter paper , thyroid , hormone , microbiology and biotechnology , antibody , immunology , biochemistry , biology , mathematical analysis , mathematics
Abstract A sensitive sandwich enzyme immunoassay of human thyroid‐stimulating hormone (hTSH) in dried blood on filter paper discs is described for mass‐screening of hypothyroidism in the neonates. One 3 mm filter paper disc per assay, on which 2.7 μl of neonatal blood had been dried, was incubated in buffer to extract hTSH. One monoclonal anti‐hTSH β‐subunit IgG 1 ‐coated polystyrene ball per assay was incubated with the extract and, after washing, with affinity‐purified rabbit antihuman chorionic gonadotropin Fab′‐β‐D‐galactosidase conjugate. Bound enzyme activity was assayed by fluorimetry using 4‐methylumbelliferyl‐β‐D‐galactoside as a substrate. The assay range of hTSH was 0.037–370 mU/l of blood, and blood hTSH levels in normal neonates were 1.33 ± 0.95 (SD) mU/l (range: 0.18–6.45 mU/l; n = 652). Therefore, this assay with a single protocol may detect not only primary hypothyroidism with abnormally high blood hTSH levels, but also secondary (pituitary) and tertiary (hypothalamic) hypothyroidism with abnormally low blood hTSH levels in the neonates, whereas the previously described enzyme immunoassays can detect only primary hypothyroidism. And this assay may be easily automated with one‐step immunoreaction.