1 Department of Clinical Immunology and Allergy, St James's University Hospital, Leeds, UK.
2 Section of Experimental Haematology, Leeds Institute of Medical Research, St. James's University Hospital, University of Leeds, Leeds, UK.
3 Department of Immunology, Southmead Hospital, North Bristol NHS Trust, Bristol, UK.
4 Leeds Musculoskeletal Biomedical Research Centre, National Institute for Health Research, Leeds Institute of Rheumatic and Musculoskeletal Medicine, Leeds, UK.