CD14 and rheumatoid arthritis: In accordance with previous results [29] the CD14+/CD16- and CD14+/CD16+ subpopulations were both present in all RA (n = 7) and healthy (n = 6) PB samples, however marked heterogeneity was observed in the RA SF, with these two CD14/CD16 subpopulations being observed together in only one out of seven SF samples analysed (data not shown).