Procollagen I Intact N-Terminal, Serum

Casandra

Casandra Test Code MC88692Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID PINPCPT Code 83519

Procollagen I Intact N-Terminal, Serum

Clinical Use

Use

This test is useful for aiding in monitoring antiresorptive and anabolic therapy in patients with osteoporosis, and serves as an adjunct in the assessment of conditions associated with increased bone turnover, such as Paget's disease. Procollagen type I propeptides, specifically PINP, reflect the synthesis rate of collagen type I, making it a sensitive marker for bone formation. It is recommended that the test be performed at baseline before starting osteoporosis therapy and again 3 to 6 months later. The assay is specific for the intact trimeric form of PINP, and a change of 21% or more from baseline PINP levels after 3 to 6 months of therapy indicates an adequate therapeutic response.

Special Instructions

This test should not be requested in patients who have recently received radioisotopes, due to potential assay interference. Specimens will be screened for radioactivity prior to analysis, and radioactive specimens will be held and assayed after the radioactivity has sufficiently decayed, causing a test delay. When serial measurements of PINP are performed, specimens should be collected at the same time of day to avoid diurnal variation in PINP levels.

Limitations

Diurnal variation exists for procollagen I intact N-terminal propeptide (PINP) levels, with values higher at night. Clearance might be affected in individuals with severe liver disease, leading to elevated PINP levels. Rare cases of human anti-mouse antibodies (HAMA) or heterophile antibodies may cause interference in immunoassays, and results must be interpreted cautiously if they do not correlate with clinical presentation.

Test Details

FDA Approved