Fig. 1
From: Surfactant protein D and bronchopulmonary dysplasia: a new way to approach an old problem
Factors that contribute to alveolar arrest in BPD. Several factors contribute to the development of inflammation in BPD. Mechanical ventilation and oxygen therapy may lead to volutrauma and barotrauma. Hyperoxia induces cell damage, apoptosis and NETosis, which are translated to a pro-inflammatory response with increased production of pro-inflammatory mediators (such as metalloproteinases, cytokines, etc.). Secondary infections and sepsis caused by pathogens (such as viruses and bacteria) activate pro-inflammatory pathways to eliminate the threat, but this inflammatory response promotes the release of pro-inflammatory cytokines (IL-6, IL-1β, TNFα, etc.) which contribute to lung injury. Chorioamnionitis and other factors may also contribute to the development of BPD. The intrinsic prematurity of the lungs from premature infants with enlarged alveolar spaces, typical of canicular or saccular morphological stages, and the immature SP-D at decreased levels also contribute to the development of BPD