Summary of the reviewed inflammation-based processes involved in chronic obstructive pulmonary disease

Mucus and inflammatory exudatesIntraluminal airwaysMucins Inflammation mediatorsChronic cough
Small airways obstruction
Epithelial remodellingBronchiolar wallsSquamous metaplasia
Basal cell hyperplasia
Structural wall thickening
Peribronchiolar fibrosisBronchiolar wallsFibrosisStructural wall thickening
Smooth muscleBronchiolar wallsIncreased size/toneStructural wall thickening
Wall infiltrateBronchiolar wallsOedema, vessels, inflammationFunctional wall thickening#
EosinophilsProximal airways and bloodEosinophil cellsMinor contribution, no consensus
FibrocytesBloodBlood circulating cellsFibrosis/repair process?
Adaptative immunityLung, extracellular matrix and alveolar attachmentsB-cells, lymphoid follicles, auto-antibodiesEmphysema
Club cell secretory proteinBronchiolar club cellsSmall airways homeostasis proteinEmphysema and small airways fibrosis

#: in contrast to structural remodelling, functional wall thickening refers to processes that do not directly affect histopathological structure.