UniQ PINP for the USA

PINP - aminoterminal propeptide of type I procollagen - is a specific type I collagen metabolite which is liberated into the bloodstream during formation of new bone. Its concentration is directly related to the rate of bone turnover. In metabolic bone diseases such as osteoporosis, PINP is a sensitive indicator for assessing increased bone turnover in postmenopausal women. PINP is a useful parameter for monitoring the effectiveness of anti-resorptive and anabolic treatment and can be used as an aid in the management of postmenopausal osteoporosis.

UniQ PINP test provides you with

A specific and sensitive means of assessing the metabolism of bone.

PINP

• Monitoring of the effect of osteoporosis treatment
• Selecting the most effective treatment
• Monitoring patient compliance
• Changes in bone turnover seen in a couple of months.

Test results should never be used alone, without a complete clinical evaluation. Read more: UniQ PINP for the USA > Risks and limitations of the procedure

Collagen is the most common protein in the human body providing structural support to bone, skin, muscle and tendons. An indicator of type I collagen turnover, such as PINP, is useful for investigating skeletal remodelling under normal and abnormal conditions.

PINP measurements provide a sensitive tool for assessing increased bone turnover in postmenopausal women and may be particularly useful for monitoring the effect of antiresorptive and anabolic therapy on bone metabolism.

UniQ PINP kit is intended to be used as an aid in the management of postmenopausal osteoporosis. Short-term changes in PINP are associated with longer-term changes in bone mineral density in postmenopausal women. Following PINP concentrations during osteoporosis treatment provides a rapid assessment of a patient’s response to osteoporosis therapy.

Marketing and sales materials

UniQ PINP RIA Monitoring of osteoporosis treatment

Instructions for use

(For informative use only. Kindly always refer to the latest package insert in the kit.)

UniQ PINP RIA IFU (GB), 67034

Safety Data Sheet

UniQ PINP RIA MSDS

Results of this assay should be used in conjunction with other pertinent clinical information for making diagnostic and therapeutic decisions. Therefore, the UniQ PINP 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.

Type I collagen is also synthesised by fibroblasts and therefore can be found in loose connective tissues together with other collagen types. However, since bone is the major collagenous organ and also metabolically active throughout life, the majority of the circulating PINP is of osteoblast origin.¹

PINP is metabolised in the liver.² Severe liver disease may affect clearance from the circulation and give rise to elevated serum PINP levels.³

As with most assays utilising secondary antibodies, samples containing antibodies (such as heterophilic antibodies) that react with rabbit/goat IgG may cause erroneous results.

1. Risteli J and Risteli L. Products of bone collagen metabolism. In: Seibel MJ, Robins SP, Bilezikian JP(eds). Dynamics of bone and cartilage metabolism. Academic Press, San Diego, 1999. p 275-287.
2. Melkko J et al. Clearance of the aminoterminal propeptides of types I and III procollagen is a physiologicalfunction of the scavenger receptor in liver endothelial cells. J Exp Med 1994;79:405-412.
3. Naylor KE and Eastell R. Measurement of biochemical markers of bone formation. In: Seibel MJ, RobinsSP, Bilezikian JP (eds). Dynamics of bone and cartilage metabolism. Academic Press, San Diego, 1999. p401-410.

Can you measure changes in cartilage metabolism with the UniQ Bone & Tissue markers?

Cartilage is mainly composed of type II collagen. As our assays measure type I and type III collagen, none of the assays can be used for measuring changes in cartilage metabolism.

Are there any substances in blood that can react on the UniQ PINP assay?

The only substances in blood that could be expected to react on the PINP assay are other peptide fragments. The cross-reactivities with the UniQ PINP assay have been tested and found to be non-significant. The PINP assay only detects the intact form of the propeptide, and does not cross-react with smaller degradation fragments such as Col-1.

What kind of test tubes should be used when running the UniQ PINP kit?

We recommend using polystyrene test tubes.

How is the collagen marker cleared from the circulation? Are there any conditions which can affect their clearance in the patient?

PINP is cleared from the circulation through a specialised part of the reticulo-endothelial system, the endothelial cells of the liver. These cells bind and internalise the propeptide by receptor-mediated endocytosis using so called scavenger receptors. Severe liver disease can affect the clearance of PINP. As renal insufficiency does not affect the concentration of the propeptide, it is very useful for monitoring changes in collagen metabolism in patients with renal failure.

What is the molecular weight of PINP?

The molecular weight of the PINP antigen is approximately 35,000 Dalton.

How should serum samples be stored and how stable is PINP in samples?

PINP is very stable in serum samples. Samples can be kept at room temperature for some days without significantly affecting the concentration of the markers and may be stored for up to 5 days at 2 - 8 °C. Storage for longer periods should be at temperatures of at least -20 °C. Experience has shown that in -20 °C samples can be stored for about five years, and in -70 °C samples can be stored for up to ten years. Freezing and thawing (4 times) does not affect the quality of the sample.

Can the PINP be detected in cell culture medium?

In cell cultures of fibroblasts, PINP is produced. As the propeptide assay does not distinguish between free propeptide and propeptide still bound to the helical procollagen structure, the assay can measure both these forms of propeptide which are commonly found in cell cultures.

Can PINP be found in urine and different biological fluids?

Aidian has developed the kit for serum use. There are, nevertheless, publications and research works where the kit has been used with other human fluids. Aidian has not validated the kit for other than serum, and does not have reference values available for other biological fluids than serum.
The marker cannot be detected in urine, as the fragment recognised by the assay is not found in urine due to its metabolism in the liver.
In the list below we have collected some information about other human biological fluids. The information in the list is indicative only.

Can the human UniQ PINP assay be used for assessing collagen metabolism in animals?

Aidian has developed and validated the kit for human serum use. There are, nevertheless, publications and research works where the kit has been used with various animal samples. Aidian does not have reference values available for other sample material than human serum. In the list below there is data collected from publications. The information in the list is indicative only.

Yes implies that the cross-reaction between the antibody used in the assay and the animal antigen should be sufficient to allow the assay to be used for that animal. No means that the antibody and the animal antigen may cross-react, but not enough to produce values in the range of the assay, or then that there seems to be no cross-reaction at all.

What is the best way for result processing with the UniQ PINP assay?

The best way to process the results is to use spline function curve fitting with linear y-axis and logarithmic x-axis.