TNF and chronic obstructive pulmonary disease: Systemic hypoxemia noted in patients with COPD is associated with acceleration of TNFα productionin alveolar macrophages and peripheral blood mononuclear cells.[6] TNF is an endogenous pyrogen that stimulates the production of other endogenous pyrogens such as IL1β.[7] Levels of CRP are also elevated in patients with COPD.[8]