Figure 2.

Cytotoxic T lymphocyte‐associated antigen 4 (CTLA‐4) blockade increased the production of interferon‐γ (IFN‐γ), tumour necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6) by peripheral blood mononuclear cells (PBMC) from patients with an acute exacerbation of COPD (AECOPD) patients, patients with stable COPD (sCOPD) and controls. Levels of (a) IFN‐γ, (b) TNF‐α, (c) IL‐6 and (d) IL‐10 in cell culture supernatants of anti‐CD3 stimulated PBMC with (right) or without (left) the addition of anti‐CTLA‐4 blocking antibodies. (e) Frequencies of IFN‐γ‐ and TNF‐α‐producing CD4⁺ and CD8⁺ T cells with CTLA‐4 blockade (right) or without CTLA‐4 blockade (left) from six participants (two AECOPD [▼], two sCOPD [▲], two controls [●]). ***P < 0·001; **P < 0·01; *P < 0·05, Wilcoxon matched‐pairs signed rank tests. [Colour figure can be viewed at wileyonlinelibrary.com]