Immunohistochemical expression of MPO, CD163 and VEGF in inflammatory cells in acute respiratory distress syndrome: a case report.

Acute respiratory distress syndrome (ARDS) is a serious medical condition occurring in patients with polytrauma, pulmonary or non-pulmonary sepsis, pneumonia and many other circumstances. It causes inflammation of the lung parenchyma leading to impaired gas exchange with a systemic release of inflammatory mediators, causing consequential lung tissue injury, hypoxemia and frequently multiple organ failure. The aim of current study was to describe expression of inflammatory markers (myeloperoxidase, CD163 and vascular endothelial growth factor) by the cells in acute phase of ARDS. The lung samples of a 20-year-old man who had suffered a serious motorbike accident were obtained for histological examination. He died on the seventh day as a consequence of respiratory failure. Our results imply that expression of CD163 was restricted to activated alveolar macrophages and monocytes. Immunopositivityof MPO was observed in neutrophil granulocytes within lung alveoli and lung blood vessels. Myeloperoxidase positivity was observed in alveolar macrophages, too. Vascular endothelial growth factor was expressed in cytoplasm of neutrophil granulocytes, monocytes, small-sized alveolar macrophages and type II pneumocytes localized mostly inside lung alveoli. On the contrary, no positivity was observed in lung endothelial cells of blood vessels.