Figure 2

Depiction of potential cytokine and cellular patterns in four hypothetical patients with rheumatoid arthritis. Upper panel: hypothetical biological activities of various cytokines. Lower panel: hypothetical biological activities of various cell types. y axis, arbitrary units of activity. For example, in patient #1 TNF does not appear bioactive, while in patient #3 B cells appear uninvolved. Especially in patient #4, however, all cytokines – and in patient #1 all cell types – appear actively engaged in the disease process. In patient #2 IL-6 may not be detectable. It is unclear to what extent which of those cells and/or cytokines is contributing and if one or several targeted therapies would be efficacious. Although such relationships have not yet been elucidated, differences in synovial cellular compositions and cytokine contents have been noted in various studies [55,59,99]. DC, dendritic cells; Fib, fibroblasts.