P34 Reliable results in continuous bioanalysis of paediatric renin samples – comprehensive quality assessment within clinical studies in children

Background As the initiator of the Renin-Angiotensin-Aldosterone-system, renin plays an essential role in the vicious circle of heart failure. Therefore, renin was determined in the investigators driven ‘Labelling of Enalapril from neonates up to adolescents’ (LENA) study to evaluate its role in paediatric heart failure. Due to the often long-lasting periods of recruitment of paediatric subjects, the assay performance has to be guaranteed over the whole recruiting time. Therefore, to ensure the high quality of the determined renin study samples after successful assay validation,1 a multi-step quality approach was used to get reliable results over a period of 30 months. Methods Based on a multi-step quality approach consisting of calibration standards (CSs), quality controls (QCs) and incurred sample reanalysis (ISR), study samples of unknown renin concentrations were determined. Results within predefined limits of CSs (6 levels) and QCs according to European Medicine Agency (EMA) guidelines were required for evaluating the study samples.2 ISR was performed for randomly selected paediatric samples to evaluate the long-term accuracy of the validated assay. Results 133 analytical runs were conducted for renin from February 2016 to August 2018. In 119 (88.8%) valid runs, a total number of 1414 of CCs and 952 of QCs were determined. Thereof 99.9% of CCs and 98.3% of QCs were in the predefined limits according to EMA. 143 incurred sample pairs were reanalysed resulting in 95.8% of samples within EMA guidelines. Using this multi-step quality approach, the reliable determination of 965 LENA paediatric study samples was guaranteed. Conclusion In addition to the assay validation, the multi-step quality approach ensured the reliability of the determined renin concentrations in the continuous bioanalysis of the paediatric study samples and guaranteed the high quality of the collected data in the LENA study. References Schaefer J, Burckhardt BB, Tins J, et al. Validated low-volume immunoassay for the reliable determination of direct renin especially valuable for pediatric investigations. J Immunoass Immunochem 2017;38:579–94. doi:10.1080/15321819.2017.1350707 Guideline on bioanalytical method validation. European Medicines Agency, London, UK (2011). Disclosure(s) Martin Feickert, Ilja Burdman, Nina Makowski, Moshin Ali, Anke Bartel, and Bjoern B. Burckhardt declare that there is no conflict of interest. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n°602295 (LENA)