1. Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
2. Institute of Cellular Medicine & NIHR Biomedical Research Centre in Ageing and Chronic Disease, Newcastle-upon-Tyne, UK
3. University Hospital Birmingham, Birmingham, UK
4. UK primary Sjogren's syndrome registry
5. Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
6. Centre for Human Metabonomics, North-West University, Potchefstroom, South Africa