Measurement of thyroid stimulating hormone (TSH) in human urine

Using a highly sensitive and specific immunoradiometric assay kit for human TSH, we measured TSH concentrations in unprocessed urines in normal subjects, in patients with primary hypothyroidism, and patients with renal disease. In five of ten normal subjects TSH was detectable in urine samples (less than 20-69 microU/day). In five patients with hypothyroidism, the urinary TSH excretion was increased. In seven out of ten patients with nephrotic syndrome, eight out of nine patients with chronic renal failure and two patients with tubular dysfunction, the urinary TSH excretion was increased. The urinary TSH excretion correlated significantly with both urinary protein excretion and urinary beta 2-microglobulin excretion. These results suggest that the renal handling of TSH involves both glomerular filtration and tubular re-absorption, and that urinary TSH excretion is increased when serum TSH is increased and either glomerular or tubular function is impaired.