Deoxypyridinoline (Dpd) Cross-Links (Serial Monitor)

Deoxypyridinoline (Dpd) Cross-Links (Serial Monitor)

Number
	511105
CPT
	82523; 82570
Synonyms
	Dpd
Test Includes
	Long-term serial monitoring of results; color graphic summary report
Special Instructions
	The account must submit the patient's Social Security number to monitor. Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient's course of therapy.
Specimen
	Urine
Volume
	10 mL
Minimum Volume
	1 mL
Container
	Plastic urine container, no preservative
Collection
	Collection before 10 AM is recommended (eg, first morning void). Do not add preservative. Specimen should not be exposed to strong light and must reach the laboratory within 72 hours of collection.
Storage Instructions
	Refrigerate
Causes for Rejection
	Blood contamination
Reference Interval
	Pediatrics:¹ Prepubertal (Tanner Stage I): <41.8 nmol Dpd/mmol creatinine Pubertal (Tanner Stage II-IV): <83.5 nmol Dpd/mmol creatinine Adults: 2.3-7.4 nmol Dpd/mmol creatinine
Use
	The Dpd test can be used as a tool to assess bone resorption rates in healthy individuals and in patients with enhanced risk of developing metabolic bone disease. Significantly high levels of Dpd are found in children, in postmenopausal women due to estrogen deficiency, and in patients with diseases that have high bone turnover rates. Dpd can be used to monitor antiresorptive therapies in postmenopausal women and in individuals diagnosed with osteoporosis.
Limitations
	This test has not been established to predict development of osteoporosis or future fracture risk.
Methodology
	Immunochemiluminometric assay (ICMA)
Additional Information
	Bone is constantly undergoing a process of remodeling that consists of degradation, or resorption, mediated by osteoclasts and rebuilding mediated by osteoblasts. This process is tightly coupled in individuals with healthy bone metabolism. In certain conditions, the rate of resorption exceeds the rate of rebuilding resulting in a net loss of bone. Deoxypyridinoline (Dpd) is a cross-link of type 1 collagen that provides tensile strength to the collagen matrix of bone. Dpd is released into circulation during bone resorption and is excreted unmetabolized into urine. Since Dpd levels are not affected by diet or physical exercise, urinary Dpd concentrations reflect the true rate of bone turnover.
Footnotes
	Conti A, Ferrero S, Giambona S, et al, “Urinary Free Deoxypyridinoline Levels During Childhood,” J Endocrinol Invest, 1998, 21(5):318-22
References
	Delmas PD, “Biochemical Markers for the Assessment of Bone Turnover,” Osteoporosis: Etiology, Diagnosis, and Management, 2nd ed, Riggs BL and Melton LJ III, eds, Philadelphia, PA: Lippincott-Raven, 1995, 319-33. Miller PD, Baran DT, Bilezikian JP, et al, “Practical Clinical Application of Biochemical Markers of Bone Turnover: Consensus of an Expert Panel,” J Clin Densitom, 1999, 2(3):323-42 (review). National Osteoporosis Foundation, Fast Facts on Osteoporosis, Washington, DC: National Osteoporosis Foundation, 1994. National Osteoporosis Foundation, Fast Facts on Osteoporosis, Arthritis, and Osteoarthritis, Washington, DC: National Osteoporosis Foundation, 1991. National Osteoporosis Foundation, The Older Person's Guide to Osteoporosis, Washington, DC: National Osteoporosis Foundation, 1993. Robins SP, Woitge H, Hesley R, et al, “Direct, Enzyme-Linked Immunoassay for Urinary Deoxypyridinoline As a Specific Marker for Measuring Bone Resorption,” J Bone Miner Res, 1994, 9(10)1643-9. Rosen HN, Dresner-Pollak R, Moses AC, et al, “Specificity of Urinary Excretion of Cross-Linked N-Telopeptides of Type I Collagen As a Marker of Bone Turnover,” Calcif Tissue Int, 1994, 54(1):26-9. Ross PD and Knowlton W, “Rapid Bone Loss Is Associated With Increased Levels of Biochemical Markers,” J Bone Miner Res, 1998, 13(5):297-302.