Changes in T-lymphocyte populations among responders and nonresponders. Median absolute numbers of peripheral blood CD3⁺ T cells (A), CD4⁺ T_con cells (B), CD8⁺ T cells (C), and CD4⁺ T_reg cells (D), and the CD4⁺ T_reg:T_con ratio (E) in patients who responded to ECP alone at week 8 (blue), patients who responded after ECP plus IL2 at week 16 (green), and patients who did not respond (red).