1. Department of Molecular Medicine and Hematology Charlotte Maxeke Johannesburg Academic Hospital National Health Laboratory System Complex and University of Witwatersrand Johannesburg South Africa
2. Department of Research Methodology and Statistics Faculty of Health Sciences University of Witwatersrand Medical School Johannesburg South Africa
3. Department of Hematology and Cell Biology University of Free State and National Health Laboratory Service Bloemfontein South Africa
4. Department of Vascular Medicine Academic Medical Centre University of Amsterdam the Netherlands