Evaluation of different bone markers in hemodialyzed patients.
BACKGROUND
Routinely, nephrologists rely on different biochemical markers like intact PTH (iPTH), bone-specific alkaline phosphatase (BALP), plasmatic calcium and phosphate. The aim of the present study was to evaluate different other bone markers like N-terminal propeptide of type 1 procollagen (P1NP), active isoform 5b of the tartrate-resistant acid phosphatase (TRAP 5b) and beta-crossLaps (CTXS) as well as full-length PTH (wPTH), presumed non-(1-84) PTH, and their ratio in the diagnosis of renal osteodystrophy with high and low turnover. We also determined 25 hydroxyvitamin D (25VTD), 1-25 dihydroxyvitamin D and homocystein (HCY).


METHODS
We performed those parameters on 73 patients with end-stage renal disease according to the manufacturers' instructions.


RESULTS
There were very strong correlations between the bone markers concentrations, particularly between BALP and P1NP (r=0.953). We did not observe any correlation between the ratio whole PTH/non-(1-84) PTH and any of the usual bone markers. This ratio was significantly (p<0.05) higher in low and high bone turnover patients than in normal patients according to the K/DOQI. We found a correlation between low levels of 25VTD and high levels of HCY.


CONCLUSIONS
BALP offers the best clinical and analytical profile as the easier marker of choice in hemodialyzed patients for the diagnosis of bone disease.
Cavalier
Etienne
E
Department of Clinical Chemistry, University Hospital of Liege, University of Liege, B-35 Domaine du Sart-Tilman, B-4000 Liege, Belgium. etienne.cavalier@chu.ulg.ac.be <etienne.cavalier@chu.ulg.ac.be>
Delanaye
Pierre
P
Collette
Julien
J
Krzesinski
Jean-Marie
JM
Chapelle
Jean-Paul
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001862:Bone Resorption / Q000097:blood / Q000201:enzymology; D001842:Bone and Bones / Q000378:metabolism*; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
D015415:Biomarkers; D007527:Isoenzymes; D006710:Homocysteine; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase