Table 1.
Summary of bone turnover biomarkers currently available and their characteristics.
| Biomarkers | Assay method | Characteristics | Reference |
|---|---|---|---|
| Bone formation markers | |||
| Alkaline phosphatase (ALP) | Serum Standard Auto-analyzer technique | Widely used but non-specific for bone turnover | Vasikaran et al. (6); Kuo and Chen (4) |
| Bone alkaline phosphatase (BALP) | Serum EIA-CLEIA | Applied for the monitoring of osteoporosis. | Kuo and Chen (4); Nagy et al. (7); Park et al. (8) |
| Osteocalcin (OC) | Serum IRMA-ECLIA | No significant utility for the assessment of osteoporosis. Promising for the investigation of osteoporosis therapy efficacy | Liu et al. (9); Kuo and Chen (4); Nagy et al. (7) |
| Procollagen type 1 C-terminal propeptide (P1CP) | Serum Radioimmunoassay | Limited study in literature. Promising for the investigation of bone formation |
Kuo and Chen (4); Nagy et al. (7) |
| Procollagen type 1 N-terminal propeptide (P1NP) | Serum RIA-ECLIA | The most sensitive marker to measure the bone formation rate the most accepted marker for monitoring drug therapy. |
Kuo and Chen (4); Glendenning et al. (10); Nagy et al. (7) |
| Bone resorption markers | |||
| Amino-terminal crosslinked telopeptide of type 1 collagen (NTX-1) | Urine EIA-CLEIA | Stable and not affected by food intake. Promising marker for osteoporosis management | Kuo and Chen (4); Nagy et al. (7) |
| Bone sialoprotein (BSP) | Serum immunoassay | Potential biomarker for osteoporosis assessment | Kuo and Chen (4) |
| Carboxy-terminal crosslinked telopeptide of type 1 collagen (CTX-1) | Serum/plasma/urine EIA-CLEIA | Specific and sensitive biomarker for osteoporosis management. Useful marker for monitoring drug therapy | Kuo and Chen (4); Glendenning et al. (10); Nagy et al. (7) |
| Cathepsin K (CTSK) | Serum ELISA | Potential marker for monitoring drug therapy | Kuo and Chen (4); Drake et al. (11) |
| Deoxypyridinoline (DPD) | Urine HPLC-EIA-CLEIA | Not very sensitive for osteoporosis management | Kuo and Chen (4); Nagy et al. (7) |
| Hydroxylysine (HYL) | Urine HPLC | Limited application due to the lack of a simple routine method | Kuo and Chen (4) |
| Hydroxyproline (HYP) | Urine Spectrophotometric technique | Not very sensitive for osteoporosis management, it has been replaced by more specific markers | Kuo and Chen (4) |
| Osteopontin (OP) | Plasma ELISA | Promising biomarker to monitor the parathyroid hormone treatment in menopausal osteoporosis | Kuo and Chen (4); Glendenning et al. (10); Nagy et al. (7) |
| Pyridinoline (PYD) | Urine HPLC | Non-specific for diagnosis and treatment of osteoporosis | Kuo and Chen (4); Nagy et al. (7) |
| Tartrate-resistant acid phosphatase 5b (TRAP 5b) |
Serum/plasma EIA | Good specificity and high sensitivity for monitoring drug therapy | Kuo and Chen (4); Nagy et al. (7) |
| Regulators of bone turnover | |||
| Dickkopf-1 (DDK-1) | Serum ELISA | Insufficient clinical data for osteoporosis management | Kuo and Chen (4); Nagy et al. (7) |
| Osteoprotegerin (OPG), | Serum ELISA | Insufficient data for clinical management of osteoporosis | Kuo and Chen (4) |
| Receptor activator of NF-kB ligand (RANKL) | Serum ELISA | Insufficient data for diagnosis and treatment of osteoporosis | Kuo and Chen (4) |
| Sclerostin | Serum ELISA | Insufficient clinical data for osteoporosis assessment | Kuo and Chen (4); Nagy et al. (7) |