Interest of bone alkaline phosphatase in hemodialysis patients

BACKGROUND: The renal osteodystrophy represent a major complication in hemodialysis. AIM: To evaluate the value of plasma bone-alkaline phosphatase (bAP) in the diagnosis of the type of renal osteodystrophy among hemodialysis patients and to seek a possible correlation between the bAP, total alkaline phosphatases (tAP) and the intact parathormone (iPTH). METHODS: We studied 67 chronic hemodialysis patients. Plasma bAP was determined by immunoenzymatic technic. iPTH (1-84) was measured by electrochimiluminescence. RESULTS: We found that bAP levels were normal (10-20 ng/ml) in 17 patients, low ( 20 ng/ml) in the 46 other patients. There is a good positive correlation between the plasmatic rate of bAP and the following parameters: the period of dialysis (R = 0.316, p = 0.009), plasmatic rate of tAP (r = 0.781, p 400 pg/ml and consequently of the biological diagnosis of hyperparathyroidism. In addition, 4 patients have a bAP <10 ng/ml with iPTH < 150 pg/ml evoking an adynamic osteopathy. CONCLUSION: plasma bAP provides useful information about bone remodelling in hemodialysis patients.