Figure 2.

Poor T-cell expansion in rheumatoid arthritis (RA) patients. Phenotyping of isolated CD4⁺ and CD8⁺ T-cell populations was performed using the cell surface markers CD45RB, CD45RA, CD45RO and CD62L. Differentiation subsets were defined as naïve cells (grey bars: CD45RB^bright, CD45RA⁺, CD45RO^-, CD62L⁺), conventional memory cells and their precursors (striped bars: CD45RB^bright/dull, CD45RA^-, CD45RO⁺, CD62L^-) and post-naïve intermediates (white bars: CD45RB^bright/dull, CD45RA^-, CD45RO^-/dull, CD62L⁺), as described previously [24]. Presumed 'central' memory cells (black bars) are CD45RB^dull, CD45RA⁺, CD45RO⁺ and CD62L⁺. Total T-cell numbers are indicated by the height of the bars. Lines across the graphs indicate the lower limits of the normal range for CD4⁺ and CD8⁺ T-cell counts. Cancer patients (n = 7 solid tumours [Table 2]) reconstitute CD4⁺ T cells largely by expansion of intermediate and memory subsets. This is not seen in RA patients (n = 12 at baseline and 1 month, n = 7 at 9 months; six patients from each of cohorts 2 and 3 [Table 2]). A similar expansion accounts for the 'overshoot' above baseline in CD8⁺ T-cells in cancer patients, whereas only a minimal transient expansion of memory CD8⁺ T-cells is observed in RA.