Abstract P251: Assay Performance And System Compatibility For RAAS Triple-A Analysis In Hypertension Profiling

Abstract

Recent studies revealed major concerns related to the accuracy of widely used clinical assays for aldosterone and renin, fueling the need for alternative and more robust bio-analytical solutions for assessment of the Renin-Angiotensin-Aldosterone-System (RAAS) in clinical samples. RAAS Triple-A profiling is a high-throughput mass-spectrometry based assay for quantification of Angiotensin I (Ang I), Angiotensin II (Ang II) and Aldosterone in serum samples. Quantified hormone levels are used to calculate markers for plasma-renin-activity (PRA-S), plasma angiotensin-converting-enzyme activity (ACE-S) and adrenal aldosterone secretion (AA2-Ratio), which can be used for clinical profiling in patients with uncontrolled hypertension. A RAAS Triple-A LC-MS/MS kit was recently launched as an In Vitro Diagnostic (IVD) device in Europe for hypertension profiling. In the current study, a comparative approach was used to assess analytical performance of the RAAS Triple-A assay on three different LC-MS/MS systems, Altis+ (Thermo Scientific), Xevo TQ-S (Waters), and Triple Quad 6500+ (Sciex) located in three different laboratories. RAAS Triple-A kits (96-well format) were used to analyze one set of n=50 triplicate human serum samples at each location. At each site, samples were sample preparation and LC-MS/MS analysis according to the RAAS Triple-A kit manual. Analytical validation of assay linearity, precision, and accuracy were evaluated at each site, and Bland-Altman-Analysis was used to test for quantification bias between sites. Results demonstrate the measured concentrations for each analyte, Ang I, Ang II, and aldosterone, were strongly correlated between sites (R 2 = Ang I: 0.996; Ang II: 0.991; Aldo: 0.983). Performance characteristics of all target analytes were in compliance with European Medical Agency (EMA) standards for bio-analytical assays on each instrument. Robust assay performance across laboratories and different LC-MS/MS systems allows for a broad clinical application of RAAS Triple-A profiling potentially improving treatment efficacy in hypertension by supporting treatment decisions with individual RAAS Triple-A profiles.