Immunoreactive Parathyroid Hormone in Early and Advanced Renal Failure

Abstract

Immunoreactive parathyroid hormone (iPTH) was measured in the serum of 20 patients with early renal failure (ERF) using three assays with different specificity. Half of these patients had elevated iPTH in one or more assays, up to twice the upper limit of normal. In contrast, 36 patients with a creatinine clearance below < 20 ml/min had an 80% elevated iPTH, up to 5 times the upper limit of normal. The patients with ERF and elevated iPTH had a lower serum calcium but no higher serum phosphate than those with normal iPTH. The differences in iPTH in early and end-stage renal failure can be explained by known differences in metabolism of different PTH forms in uremia.

Serum 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin in Chronic Renal Failure

“…In the case of PTH it is possible that measurements of amino-terminal immunoreactive PTH (iPTH) may lead to another result. However, in renal failure carboxy-terminal iPTH is reported (Lilienfeld-Toal et al, 1982) to correlate better with parameters of PTH action in bone than amino-terminal reactive iPTH (15). From our studies and in the light of the above findings, we can conclude, that factors other than the concentrations of 25 OH D, calcium, phosphate, or PTH in the serum are more important for the regulation of serum 1, 25(OH)2D in end stage renal failure.…”

Comparison of 1-84 and intact parathyroid hormone assay in pediatric dialysis patients

“…PTH fragments are known to accumulate in patients with chronic renal failure (CRF), and thus such assays that do not solely measure the 1-84 PTH molecule will result in overestimation of the presumed biological hormone [6,7,8,9,10,11]. This phenomenon and the presence of PTH fragments with possible antagonistic properties has been suggested to explain why PTH values need to be maintained at higher values than normal to prevent adynamic bone disease (ABD) in patients with ESRD [12].…”