1 Centre for Rheumatology, Division of Medicine, University College London Hospital, London, UK.
2 National Institute for Health Research, Manchester Biomedical Research Centre, Manchester University NHS Foundation Trust, The University of Manchester, UK.
3 Neuromuscular Division, Neurology Department, The University of Kansas Medical Center, Kansas City, KS, USA.
4 Environmental Autoimmunity Group, National Institute of Environmental Health Sciences, National Institutes of Health, Bethesda, MD, USA.
5 Environmental Autoimmunity Group, National Institute of Environmental Health Sciences, National Institutes of Health, Bethesda, MD, USA. riderl@mail.nih.gov.