Role of cytokines in hyperoxia mediated inflammation in the developing lung.

The development of Chronic Lung Disease of Prematurity (CLD) has been associated with the use of hyperoxic conditions during ventilation. Inflammation has been demonstrated to contribute to the development of this disease, both on histological examination of diseased lungs, and by the use of bronchoalveolar lavage. Hyperoxia is believed to contribute to this inflammatory process by causing direct injury to epithelial and endothelial cells. The formation of reactive oxygen species is thought to result in production of cytokines. These act within a complex network, orchestrating an inflammatory response. Evidence for a role of cytokines in CLD has been inferred by studies in human infants showing increased concentrations of cytokines, growth factors and inflammatory cells at early stages in infants destined to develop CLD. These findings have been supported by the use of animal models of hyperoxic lung injury. The treatment of CLD is currently centered on the suppression of cytokine production. As understanding of this disease increases, more specific targets are being developed which aim to reduce the oxidative load on the lung, and prevent recruitment of inflammatory cells that are responsible for the tissue damage underlying this disease.