An Approach To The Problem Of Renal Hyperparathyreoidism, As To A Disorder Of Growth Of The Separate Parathyroid Cell Clones (an implication for the early preventive treatment of hyperparathyreoidism in chronic renal failure)

Abstract

The aim of this study was to estimate the parathyroid cells proliferation rate according to the expression of Ki-67 antigen. We retrieved embedded tissue blocks of parathyroids removed at surgery from 14 dialysis patients. New sections were cut and examined for expression of Ki-67, a cell-cycle marker, using MIB-1 antibody with antigen retrieval, and tonsil or thymus as positive control. Using an eyepiece graticule with unbiased square-counting frame, positively labeled chief cells were counted and the prevalence of Ki-67 positive cells per 104 cells (label index or LI) was calculated. Label index converted to cell birth rate assuming that the duration of Ki-67 expression was 24 hours. With this assumption mean cell birth rate [%/year] and corresponding cell life span [years] were calculated (mean cell birth rate [%/year] = LI(10000) × 365/100000 × 100 = LI × 3,65; and cell life span [years] = 100/LI × 3,65). Our calculations confirmed the point that parathyroid cell growth is very slow. We suggest that it is reasonable to start the preventive treatment with phosphate- binders and calcitriol (1-alfa-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol) minimum for 8,3 years before the start of dialysis treatment.