(2) Systemic inflammatory response:COPD is accompanied by significant systemic inflammatory responses, marked by elevated levels of acute-phase proteins (e.g., C-reactive protein [CRP], fibrinogen), increased white blood cell and band cell counts due to bone marrow stimulation, and elevated cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and IL-6, all of which may activate the vascular endothelium (7). Here, TNF is linked to chronic obstructive pulmonary disease.