1 Department of Paediatric Haematology and Oncology, The Great North Children's Hospital, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
2 Department of Rheumatology, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
3 Ear, Nose and Throat Service, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
4 Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.
5 Department of Cellular Pathology, South Tees Hospitals NHS Foundation Trust, Middlesbrough, UK.
6 Department of Cellular Pathology, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.