CD4 and rheumatoid arthritis: The aims of this study are first, to confirm the T helper cell subset imbalance previously described in RA; second, to explore whether this imbalance is detectable in a small sample size, if the standard definition of Th subsets is relaxed in favour of Th cell plasticity (unbiased marker combinations) and third, to test whether innovative techniques (mass cytometry and unsupervised clustering algorithm) facilitate the identification of pro- and anti-inflammatory CD4+ T cell subsets over standard techniques (flow cytometry and manual bi-axial gating) in a small sample size.