Utility of serum tartrate-resistant acid phosphatase (TRACP5b) as a bone resorption marker in patients with chronic kidney disease: independence from renal dysfunction.
BACKGROUND
Serum tartrate-resistant acid phosphatase (TRACP) 5b levels were assessed in predialysis patients with chronic kidney disease (CKD). The aim of the study was to establish the usefulness of a new assay for TRACP5b in assessing bone turnover in these patients.


METHODS
Serum concentrations of two bone resorption markers, TRACP5b and N-terminal cross-linking telopeptide of type I collagen (NTX); two bone formation markers, bone specific alkaline phosphatase (bone ALP) and intact osteocalcin (OC[1-49]); and PTH were measured in 98 predialysis CKD patients.


RESULTS
Log serum TRACP5b and other bone markers were significantly negatively correlated with glomerular filtration rate (GFR) and positively correlated with log serum PTH, suggesting an increase in serum bone markers with development of secondary hyperparathyroidism. Multiple regression analysis including age, gender, BMI, the presence of diabetes, GFR and log serum PTH showed an association of log serum PTH with log serum TRACP5b and other bone markers. GFR was associated with log serum NTX and log OC[1-49], but not with log serum TRACP5b or log bone ALP. These data show that renal dysfunction does not influence serum TRACP5b and bone ALP, but has an influence on NTX and OC[1-49].


CONCLUSIONS
Serum TRACP5b may be a good marker for serum bone resorption in predialysis CKD patients, as it is not affected by renal dysfunction.
Yamada
Shinsuke
S
Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
Inaba
Masaaki
M
Kurajoh
Masafumi
M
Shidara
Kaori
K
Imanishi
Yasuo
Y
Ishimura
Eiji
E
Nishizawa
Yoshiki
Y
D000135:Acid Phosphatase / Q000097:blood*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001862:Bone Resorption / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D012680:Sensitivity and Specificity; D000071681:Tartrate-Resistant Acid Phosphatase
D015415:Biomarkers; D007527:Isoenzymes; D010281:Parathyroid Hormone; C000605510:ACP5 protein, human; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase