Figure 3

Thymic reserve in lymphopenic cancer and rheumatoid arthritis (RA) patients. The proportion of T cells containing a T-cell receptor excision circle (TREC) was measured longitudinally in cancer (n = 7 solid tumours [Table 2]) and RA (n = 12 at baseline and 1 month, six patients from both of cohorts 2 and 3 [Table 2]; and n = 7 at 9 months, three from cohort 2 and four from cohort 3) patients' pure CD4⁺ T-cells and following cell sorting of naïve cells. In cancer patients TRECs rapidly rose within 1 month and then slowly returned to pretreatment levels by 8 months. In RA patients there was a slow but sustained rise in TRECs over that time, achieving similar peak levels to cancer patients by 9 months.