Performance of two new solid-phase ligand assays for TSH using monoclonal antibodies

Three ligand assays for TSH using monoclonal antibodies, an IRMA, an ELISA and a DELFIA were compared with a standard DAB RIA technique. The IRMA proved to be superior in respect to sensitivity, precision, reproducibility and practicality. The highest sensitivity yet, was achieved by DELFIA. IRMA, ELISA and DELFIA are performable on a daily routine basis. ELISA and DELFIA have the additional advantage of being non-isotopic immunoassays (NIIA). Under routine conditions IRMA reveals the best discrimination of hyperthyroid from euthyroid patients by basal TSH. This fact improves the TSH determination's clinical value considerably and may in the future--if confirmed--change the diagnostic schemes in use at present, e.g. rendering most of the TRH-tests unnecessary.