The proposal aims to further characterise the clinical significance and the underpinning pathotypes of 4 PSS subtypes. The specific objectives are:
1. To understand the natural history of the different PSS subtypes.
2. To validate the transcriptomic signatures of the PSS subtypes and re-calibrate (if necessary) for non-UK cohorts.
3. To further characterise the underpinning pathobiological profiles of the four PSS subtypes
4. To explore whether the four subtypes respond differently to treatments by reanalysing data from two clinical trials (JOQUER (hydroxychloroquine) and TRACTISS (Rituximab)