1 Department of Rheumatology, Royal Wolverhampton Hospitals NHS Trust, Wolverhampton, UK.
2 Medical College, The Aga Khan University, Karachi, Pakistan.
3 Department of Rheumatology, Royal Wolverhampton Hospitals NHS Trust, Wolverhampton.
4 Division of Musculoskeletal and Dermatological Sciences, Centre for Musculoskeletal Research, School of Biological Sciences, The University of Manchester, Manchester.
5 City Hospital Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK.