[Tartrate-resistant acid phosphatase--TRAP 5b--as a novel marker of bone resorption in patients with irreversible renal failure treated with dialysis].
The evaluation of renal osteodystrophy in everyday practise is based on measurements of non-invasive bone markers. TRAP 5b has been considered as a potentially useful marker of bone resorption rate. We assessed the clinical usefulness of TRAP 5b as a marker of bone resorption in renal osteodystrophy in comparison with standard marker which is intact parathormone (iPTH) level.


METHODS
We studied 84 patients: 61 on hemodialysis (HD) for 43 +/- 25 months (36M, 25F aged 59 +/- 25 yr.) and 23 on continuous ambulatory peritoneal dialysis (CAPD) for 47 +/- 28 months (12M, 11F, aged 53 +/- 23 yr). The following parameters were determined in serum: TRAP 5b, iPTH, Ca, P, total acid phosphatase (AP). Serum TRAP 5b activity was measured using a solid phase immunofixed enzyme activity assay Bone TRAP (SBA Finland). Intact PTH was measured using immunoradiometric assay (Incstar USA). According to iPTH level patients were divided into 3 subgroups: A--(iPTH < 100 pg/ml); B--(iPTH 100 - 450 pg/ml); C--(iPTH > 450 pg/ml).


RESULTS
We found significant correlation between iPTH and TRAP in dialysed pts. (r = 0.6764, p < 0.0001). In patients with high turnover renal osteodystrophy-group C significantly higher values of TRAP were found in comparison with patients with low turnover renal osteodystrophy-group A (7.5 +/- 1.4 vs. 2.9 +/- 1.4 p < 0.001). There was not significant correlation between values of TRAP and gender, cause of irreversible renal failure as well as method of dialysotherapy.


CONCLUSIONS
In conclusion, highly significant correlation between level of TRAP 5b and iPTH found in our study justifies using TRAP 5b as an important marker of bone resorption rate in clinical practice.
Nowak
Zbigniew
Z
Wojskowy Instytut Medyczny, Klinika Nefrologii ze Stacja Dializ CSK MON w Warszawie. zbnowak@wp.pl
Konieczna
Maria
M
Wańkowicz
Zofia
Z
D000135:Acid Phosphatase / Q000097:blood*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001862:Bone Resorption / Q000097:blood / Q000201:enzymology*; D002118:Calcium / Q000097:blood; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000097:blood / Q000201:enzymology*; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010710:Phosphates / Q000097:blood; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D000071681:Tartrate-Resistant Acid Phosphatase
D015415:Biomarkers; D007527:Isoenzymes; D010281:Parathyroid Hormone; D010710:Phosphates; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002118:Calcium