Figure 2.

Putative mechanism of airway-centered inflammation and fibrosis in bronchiolitis obliterans syndrome after lung transplantation. Different injurious processes including alloimmune responses, autoimmune responses, external stimuli, and airway ischemia induces inflammation in the small airways, which results in damage to the epithelium and other tissues. These damaged tissues may further augment tissue injury (such as exposure of autoantigen, vascular damage leading to ischemia, epithelial loss resulting in reduced barrier function). Ultimately this leads to remodeling and fibrosis termed obliterative bronchiolitis, while other anatomical compartments of the lung remain relatively intact.