Francis O'Neill1, Eve McLoughlin1, Meliana Riwanto2, Jasmin Manz2, Andreas Adler1, Emma Sutill1, Tauseef Khan1, Rachel Haywood1, Christopher W M Kay3, Francesco D'Aiuto4, Marietta Charakida1, Ulf Landmesser2, John Deanfield5. 1. Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK. 2. Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland. 3. Institute of Structural & Molecular Biology and London Centre for Nanotechnology, University College London, London, UK. 4. Periodontology Unit, Department of Clinical Research, University College London Eastman Dental Institute, London, UK. 5. Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK; National Institute for Cardiovascular Outcomes Research, University College London, London, UK. Electronic address: j.deanfield@ucl.ac.uk.
Abstract
BACKGROUND: Recent failures of clinical trials promoting HDL-elevating therapies have prompted research groups to focus on its functional activity in disease. Endothelial effects of HDL can be measured with in vitro cell assays. The reproducibility and biological relevance of these assays have not been explored both in healthy individuals and those at increased cardiovascular (CV) risk. METHODS: HDL dependent nitric oxide (NO) bioavailability, superoxide (SO) production and serum paraoxonase-1 (PON-1) activity were measured in 35 healthy adults (34.37 24-49) and 8 patients (43.56 37-49) suffering from a chronic inflammatory condition (periodontitis-PD). Assay reproducibility was assessed by independent technicians on consecutive days to determine inter and intra analyser variability for each assay. The 35 healthy individuals were further divided into young (n = 16) and middle aged (n = 19) groups and compared with regards to HDL functions. Within-subject biological variation of HDL function was determined in a sub-group of 25 healthy volunteers at intervals of one day and 1 month, and in 8 patients at intervals of one day and 1 week. Power curves were also generated to estimate the number of patients that would be required for HDL functional assays in a cross-over and parallel study design. RESULTS: NO bioavailability was the most reproducible assay in healthy adults (coefficient of variation = 1.72%, 1.92 - intra and inter respectively) and PD patients (CV = 4.4% and 5.5%). All measures demonstrated no statistical difference between young and healthy middle aged population. No single assay demonstrated significant variations over time, indicating that within patient variations are negligible. Our power curves for NO bioavailability and PON-1 activity suggest that low number of patients will be required to detect significant differences in HDL function in a cross over and parallel study design. CONCLUSION: This study suggests that in vitro HDL functional assays are reliable and can be used to assess HDL functionality in healthy and diseased populations. NO bioavailability was the most reproducible assay, but PON-1 activity remains the most practical for application in clinical trials due to its capacity for scale. Crown
BACKGROUND: Recent failures of clinical trials promoting HDL-elevating therapies have prompted research groups to focus on its functional activity in disease. Endothelial effects of HDL can be measured with in vitro cell assays. The reproducibility and biological relevance of these assays have not been explored both in healthy individuals and those at increased cardiovascular (CV) risk. METHODS: HDL dependent nitric oxide (NO) bioavailability, superoxide (SO) production and serum paraoxonase-1 (PON-1) activity were measured in 35 healthy adults (34.37 24-49) and 8 patients (43.56 37-49) suffering from a chronic inflammatory condition (periodontitis-PD). Assay reproducibility was assessed by independent technicians on consecutive days to determine inter and intra analyser variability for each assay. The 35 healthy individuals were further divided into young (n = 16) and middle aged (n = 19) groups and compared with regards to HDL functions. Within-subject biological variation of HDL function was determined in a sub-group of 25 healthy volunteers at intervals of one day and 1 month, and in 8 patients at intervals of one day and 1 week. Power curves were also generated to estimate the number of patients that would be required for HDL functional assays in a cross-over and parallel study design. RESULTS: NO bioavailability was the most reproducible assay in healthy adults (coefficient of variation = 1.72%, 1.92 - intra and inter respectively) and PDpatients (CV = 4.4% and 5.5%). All measures demonstrated no statistical difference between young and healthy middle aged population. No single assay demonstrated significant variations over time, indicating that within patient variations are negligible. Our power curves for NO bioavailability and PON-1 activity suggest that low number of patients will be required to detect significant differences in HDL function in a cross over and parallel study design. CONCLUSION: This study suggests that in vitro HDL functional assays are reliable and can be used to assess HDL functionality in healthy and diseased populations. NO bioavailability was the most reproducible assay, but PON-1 activity remains the most practical for application in clinical trials due to its capacity for scale. Crown
Authors: Nicholas J Woudberg; Sarah Pedretti; Sandrine Lecour; Rainer Schulz; Nicolas Vuilleumier; Richard W James; Miguel A Frias Journal: Front Pharmacol Date: 2018-01-22 Impact factor: 5.810
Authors: Francis O'Neill; Marietta Charakida; Eric Topham; Eve McLoughlin; Neha Patel; Emma Sutill; Christopher W M Kay; Francesco D'Aiuto; Ulf Landmesser; Peter C Taylor; John Deanfield Journal: Heart Date: 2016-11-16 Impact factor: 5.994
Authors: Flavia De Conti Cartolano; Caroline Pappiani; Maria Camila Prupper de Freitas; Antonio M Figueiredo Neto; Antônio Augusto Ferreira Carioca; Nágila Raquel Teixeira Damasceno Journal: Arq Bras Cardiol Date: 2018-04 Impact factor: 2.000
Authors: Scott T Chiesa; Marietta Charakida; Eve McLoughlin; Helen C Nguyen; Georgios Georgiopoulos; Laura Motran; Yesmino Elia; M Loredana Marcovecchio; David B Dunger; R Neil Dalton; Denis Daneman; Etienne Sochett; Farid H Mahmud; John E Deanfield Journal: Eur Heart J Date: 2019-11-14 Impact factor: 29.983