Prospective, observational study in patients with early symptomatic inflammatory arthritis (http://www.peac-mrc.mds.qmul.ac.uk/). Biological samples (synovial tissue & fluids) are collected at two timepoints - Baseline & Follow-up (6 month), please note figures for baseline samples are represented (6 month sample availability on request). Demographic & clinical data is available & collected at 5 timepoints over a 1-year follow-up period (Baseline, 3, 6, 9 & 12 months). Current recruitment status for Psoriatic Arthritis cohort is 44 patients (1st April 2019).

Prospective, observational study in patients with early symptomatic inflammatory arthritis (http://www.peac-mrc.mds.qmul.ac.uk/). Biological samples (synovial tissue & fluids) are collected at two timepoints - Baseline & Follow-up (6 month), please note figures for baseline samples are represented (6 month sample availability on request). Demographic & clinical data is available & collected at 5 timepoints over a 1-year follow-up period (Baseline, 3, 6, 9 & 12 months). Current recruitment status for the Undifferentiated/Non-Inflammatory Arthritis cohort is 65 patients (1st April 2019).

Exploratory, prospective, observational, single site study. To explore the evolution of clinical disease characteristics in patients with psoriatic arthritis who have failed standard non-biologic therapy. Biological samples (synovial & skin tissues, & fluids) collected at multiple timepoints (details available on request), please note figures for baseline samples are represented (availability of samples from other timepoints on request). Demographic & clinical data is available & collected at multiple timepoints over a 48 week follow-up period. Recruitment status for this study is 31 patients.

Observational, single site study. There are many reports that strongly suggest that certain bacteria living in the mouth and in the intestines of RA patients may cause and/or worsen RA. The purpose of the observational IRMA study is to identify RA patients who also have periodontitis (inflammation in their gums caused by bacteria) and compare them to healthy individuals. We will compare the presence of bacteria in the mouth with the RA disease activity and severity and investigate whether the presence of periodontitis and certain bacteria are related to the inflammation in joints and severity of RA disease. The long term goal is to determine if treating periodontitis, caused by certain bacteria, may help to improve the outcomes for patients with RA. Current recruitment status for this study is 12 patients.