Analytical evaluation of P1NP assay, a biochemical marker of bone turnover
Marko Marcius
[*]
[1]
Nada Vrkić
[2]
Biserka Getaldić-Švarc
[3]
Author notes:
[*] Corresponding author: marko_marcius@yahoo.co.uk
Aim: Evaluation of the characteristics of total P1NP assay performed on biological material in clinical laboratory conditions, and comparison of evaluation results with the assay properties declared by the manufacturer.
Methods: Analytical evaluation of P1NP assay was conducted according to the European Committee for Clinical Laboratory Standards (ECCLS) protocol. Amino-terminal propeptide of type I procollagen (P1NP) was determined by electrochemiluminescent immunoassay on an Elecsys 2010 automated analyzer (Roche Diagnostics, Mannheim, Germany).
Results: Satisfactory results were achieved for within-run and between-run imprecision during 10 days. Deviation from declared control sample values showed a satisfactory level of accuracy, not exceeding the limit of declared 1 SD on any measurement. Study results for linearity and assessment of hemoglobin interference entirely confirmed the manufacturer‘s declarations. Moreover, the presence of hemolysis showed no interference due to hemoglobin up to 1.61 mmol/L (32% higher than that stated by the manufacturer). Interference results for lipemia and hyperbilirubinemia (>610 µmol/L and 15.0 mmol/L, respectively) showed poorer values compared to those declared. Bilirubin and triacylglycerol interference was confirmed in concentrations that were on an average by 30% lower than those declared by the manufacturer.
Conclusion: Total P1NP test is suitable for routine use in medical laboratory. The Elecsys 2010 automated analyzer ensures rapidity, simple manipulation, calibration stability, control samples, and computer support for the analysis of control and patient samples.
Keywords: analytical evaluation; amino terminal propeptide type I procollagen; P1NP; electrochemiluminescent immunoassay; bone markers
