Determination of the concentration of thyroid hormones in dialysate and assessment of the loss of thyroid hormone during hemodialysis
Beyer, H.K.; Schuster, P.; Pressler, H.
Nuklearmedizin. Nuclear Medicine 19(6): 288-293
1980
ISSN/ISBN: 0029-5566 PMID: 7279678 Document Number: 155757
In order to determine the hormone concentration in a dialysate, the commercially available radioimmunoassay test of Dow-Lepetit for determination of free thyroid hormones in serum had to be modified. The results raised the suspicion that additional protein-bound hormone had passed the membrane. This could be demonstrated by the addition of Thiomersal. In 64 patients examined 1 and 5 hrs after the beginning of hemodialysis the mean total hormone concentration in the dialysate was 12.05 pg/ml for thyroxine and 5.47 pg/ml for triiodothyronine. The resulting loss of total hormone in hemodialysis patients, calculated for 1 week, amounted to 2.25 microgram triiodothyronine and 4.87 microgram thyroxine. The comparison with the physiologic renal elimination of thyroid hormone shows that the hormone elimination in hemodialysis patients is negligibly small. The quantitative determination of the protein concentration in the dialysate gave 384 ng/ml and was close to the limit of sensitivity of the method and consequently uncertain. It can be said, however, that the loss of protein is without clinical relevance.