Renal osteodystrophy with hyperparathyroidism: the diagnostic value of intact parathormone, alkaline phosphatase, osteocalcin and procollagen.

Abstract

In 27 patients on periodic haemodialysis, serum levels of alkaline phosphatase (ALP), osteocalcin (BGP), intact parathyroid hormone (PTHi) and its two fragments, terminal COOH (PTH-Cter) and middle molecule (PTH-MM), and procollagen type 1 carboxy-terminal extension peptide (P1CP) were measured. The same patients underwent radiography of the skull and of the hands, ultrasonography of the parathyroids and scintigraphy of the skeleton with 99mTc-MDP. The study was completed by the measurement of aluminium (Al) in the blood and the deferoxamine test (DFO). Two groups of patients emerged, one (group A, n = 14) with PTHi greatly increased (201.07 +/- 109.72 pg/mL) and the other (group B, n = 13) with values within the normal range (32.69 +/- 17.06 pg/mL) (p < 0.001). In group A, ALP, BGP and particularly P1CP were increased with a statistically significant difference compared to group B. Specific radiographic alterations were found in 12 patients of group A; 7 patients also had hypertrophy of the parathyroids. There was no difference in the scintigraphic alterations of the skeleton between the two groups. The authors conclude that it is the association of the high values of PTHi with those of the markers of bone metabolism, the normal level of Al, the negativity of the DFO test and the radiological alterations which together allow the diagnosis of renal osteodystrophy with hyperparathyroidism.