1 Department of Infectious Diseases, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, L14 5AB, UK.
2 Department of Cardiology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, L14 5AB, UK.
3 Department of Biostatistics, University of Liverpool, Liverpool, 3BX, UK.
4 Department of Rheumatology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, L14 5AB, UK.
5 Department of Women's & Children's Health, Life Course and Medical Sciences, University of Liverpool, Liverpool, L69 3BX, UK. Electronic address: [email protected].