Intact N-Terminal Propeptide of Type 1 Procollagen

CPT: 82523
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Test Details


  • PINP


Indicator of type I collagen turnover


Results of this assay should be used in conjunction with pertinent clinical information for making diagnostic and therapeutic decisions. This assay is not recommended for use as a screening procedure to detect the presence of osteoporosis in the general population. When evaluating subsequent samples, collect the samples at the same time of the day, as there is a diurnal variation of PINP with the values being higher at night. PINP is metabolized in the liver. Severe liver disease may affect clearance from the circulation and give rise to elevated serum PINP levels.


Radioimmunoassay (RIA)

Reference Interval

• Male: 22−87 μg/L

• Female:

− Premenopausal: 19−83 μg/L

− Postmenopausal: 16−96 μg/L

Additional Information

Approximately 90% of the organic matrix of mammalian bone consists of type 1 collagen that is cross-linked at the N-terminal and C-terminal ends.1 This highly cross-linked structure provides for the basic fabric and tensile strength of bone tissue.1,2 The collagen infrastructure of bone undergoes a continuous process of remodeling that involves osteoclast-mediated bone resorption and osteoblast bone formation. Bone collagen is derived from type 1 procollagen, which consists of three amino acid chains that are intertwined to form a rod-like helix.2 Type 1 procollagen has propeptide extensions at both ends of the molecule, which are removed by specific proteinases before the collagen molecules are assembled into collagen fibers. The cleaved propeptides can be found in the circulation where their concentration reflects the synthesis rate of type I collagen. The serum concentration of the amino-terminal propeptide of type I procollagen (P1NP) is directly proportional to the amount of new collagen produced by osteoblasts. Metabolic bone diseases are characterized by imbalances in bone turnover that occur as the result of an uncoupling between bone formation and resorption. As an indicator of type I collagen production, P1NP can be useful in the assessment of skeletal remodeling under normal and abnormal conditions. P1NP has used to monitor bone turnover in postmenopausal women3-6 and to monitor the effect of antiresorptive and anabolic therapy of bone metabolism.7-19 P1NP has also proved useful in the monitoring of treatment of patients receiving teriparatide therapy.20,21 The determination of P1NP has been used to assess increases in type I collagen turnover in Paget disease of bone.22-24 P1NP measurement has also been used to assess bone metastatic activity in a number of malignancies and in predicting survival.25-27

Specimen Requirements




0.5 mL

Minimum Volume

0.4 mL (Note: This volume does not allow for repeat testing.)


Red-top tube or gel-barrier tube

Patient Preparation

No radioactive isotopes administered 48 hours prior to venipuncture.


If a red-top tube is used, transfer separated serum to a plastic transport tube.

Storage Instructions


Causes for Rejection

Nonserum sample received; radioactive isotopes administered

Clinical Information


1. Endes DB, Rude RK. Mineral and bone metabolism. In: Burtis CA, Ashwood ER, eds. Tietz Textbook of Clinical Chemistry. 3rd ed. Philadelphia, Pa: WB Saunders Co;1999:1349-1457.
2. Hammett-Stabler CA. Osteoporosis, From Pathophysiology to Treatment: Special Topics in Diagnostic Testing. Washington DC: AACC Press; 2004.
3. Saarto T, Blomqvist C, Risteli J, et al. Aminoterminal propeptide of type I procollagen (PINP) correlates to bone loss and predicts the efficacy of antiresorptive therapy in pre- and postmenopausal nonmetastatic breast cancer patients. Br J Cancer. 1998; 78(2):240-245.
4. Garnero P, Sornay-Rendu E, Duboeuf F, et al. Markers of bone turnover predict postmenopausal forearm bone loss over 4 years: The OFELY study. J Bone Miner Res. 1999; 14(9):1614-1621. 10469291
5. Scariano JK, Garry PJ, Montoya GD, et al. Diagnostic efficacy of serum cross-linked N-telopeptide (NTx) and aminoterminal procollagen extension propeptide (PINP) measurements for identifying elderly women with decreased bone mineral density. Scand J Clin Lab Invest. 2002; 62(3):237-243. 12088343
6. Scariano JK, Glew RH, Bou-Serhal CE, et al. Serum levels of cross-linked N-telopeptides and aminoterminal propeptides of type I collagen indicate low bone mineral density in elderly women. Bone. 1998; 23(5):471-477. 9823455
7. Garnero P, Stevens RE, Ayres SA, et al. Short-term effects of new synthetic conjugated estrogens on biochemical markers of bone turnover. J Clin Pharmacol. 2002; 42(3):190-196. 11865965
8. Fink E, Cormier C, Steinmetz P, et al. Differences in the capacity of several biochemical bone markers to assess high bone turnover in early menopause and response to alendronate therapy. Osteoporos Int. 2000; 11(4):295-303. 10928218
9. Hannon R, Blumsohn A, Naylor K, et al. Response of biochemical markers of bone turnover to hormone therapy: Impact of biological variability. J Bone Miner Res. 1998; 13(7):1124-1133. 9661076
10. Peris P, Alvarez L, Monegal A, et al. Biochemical markers of bone turnover after surgical menopause and hormone replacement therapy. Bone. 1999; 25(3):349-353. 10495139
11. Reginster JY, Sarkar S, Zegels B, et al. Reduction in PINP, a marker of bone metabolism, with raloxifene treatment and Its relationship with vertebral fracture risk. Bone. 2004; 34(2):344-351. 14962813
12. Sharp CA, Evans SF, Risteli L, et al. Effects of low- and conventional-dose transcutaneous HRT over 2 years on bone metabolism in younger and older postmenopausal women. Eur J Clin Invest. 1996; 26(9):763-771. 8889438
13. Suvanto-Luukkonen E, Risteli L, Sundstrom H, et al. Comparison of three serum assays for bone collagen formation during postmenopausal estrogen-progestin therapy. Clin Chim Acta. 1997; 266(2):105-116. 9437539
14. Black DM, Greenspan SL, Ensrud KE, et al. The effects of parathyroid hormone and alendronate alone or in combination in postmenopausal osteoporosis. N Engl J Med. 2003; 349(13):1207-1215. 14500804
15. Liberman UA, Weiss SR, Broll J, et al. Effect of oral alendronate on bone mineral density and the incidence of fractures in postmenopausal osteoporosis. The Alendronate Phase III Osteoporosis Treatment Study Group. N Engl J Med. 1995; 333(22):1437-1443. 7477143
16. Stepan JJ, Vokrouhlicka J. Comparison of biochemical markers of bone remodeling in the assessment of the effects of alendronate on bone in postmenopausal osteoporosis. Clin Chim Acta. 1999; 288(1-2):121-135. 10529464
17. Bauer DC, Black DM, Garnero P, et al. Change in bone turnover and hip, nonspine, and vertebral fracture in alendronate-treated women: The fracture intervention trial. J Bone Miner Res. 2004; 19(8):1250-1258. 15231011
18. Heikkinen J, Vaheri R, Kainulainen P, et al. Long-term continuous-combined hormone replacement therapy in the prevention of postmenopausal bone loss: A comparison of high- and low-dose estrogen-progestin regimens. Osteoporos Int. 2000; 11(11):929-937. 11193245
19. Heikkinen JE, Vaheri RT, Ahomaki SM, et al. Optimizing continuous-combined hormone replacement therapy for postmenopausal women: A comparison of six different treatment regimens. Am J Obstet Gynecol. 2000; 182(3):560-567. 10739508
20. Eastell R, Krege JH, Chen P, et al. Development of an algorithm for using PINP to monitor treatment of patients with teriparatide. Curr Med Res Opin. 2006; 22(1):61-66. 16393431
21. McClung MR, San Martin J, Miller PD, et al. Opposite bone remodeling effects of teriparatide and alendronate in increasing bone mass. Arch Intern Med. 2005; 165(15):1762-1768. 16087825
22. Alvarez L, Peris P, Pons F, et al. Relationship between biochemical markers of bone turnover and bone scintigraphic indices in assessment of Paget's disease activity. Arthritis Rheum. 1997; 40(3):461-468. 9082934
23. Alvarez L, Ricos C, Peris P, et al. Components of biological variation of biochemical markers of bone turnover in Paget's bone disease. Bone. 2000; 26(6):571-576. 10831927
24. Pons F, Alvarez L, Peris P, et al. Quantitative evaluation of bone scintigraphy in the assessment of Paget's disease activity. Nucl Med Commun. 1999; 20(6):525-528. 10451864
25. Díaz-Martín MA, Traba ML, De La Piedra C, et al. Aminoterminal propeptide of type 1 collagen and bone alkaline phosphatase in the study of bone metastases associated with prostatic carcinoma. Scand J Clin Lab Invest. 1999; 59(2):125-132. 10353326
26. Koizumi M, Yonese J, Fukui L, et al. The serum level of the amino-terminal propeptide of type 1 procollagen Is a sensitive marker for prostate cancer metastasis to bone. BJU Int. 2001; 87(4):348-351. 11251528
27. Jukkola A, Bloigu R, Holli K, et al. Postoperative PINP in serum reflects metastatic potential and poor survival in node-positive breast cancer. Anticancer Res. 2001; 21(4B):2873-2876.11712779


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
140850 Propeptide Type I Collagen 47255-5 140851 Propeptide Type I Collagen ug/L 47255-5

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