TNF and lymphopenia: The rapid stimulation of T helper 1 (Th1) cells leads to an imbalanced pro-inflammatory response, with particularly high levels of expression of IL-6 and tumor necrosis factor (TNF), leading to impaired acquired immunity (lymphopenia) and an uncontrolled innate response, further propagated by the release of pro-inflammatory cytokines by alveolar macrophages (25, 42).