To investigate the vascular endothelial growth factor (VEGF) expression in the lung tissue of acute respiratory distress syndrome (ARDS) patients and also the VEGF plasmatic levels of these patients.
We realized a prospective study including 10 patients diagnosed with ARDS. Lung specimens from ARDS patients were obtained by bronchoscopy or by autopsy in case of the deceased patients. The controls were 10 patients deceased from other causes than ARDS from whom necroptic pulmonary tissue samples. The determination of VEGF expression in the pulmonary tissue was performed using specific monoclonal antibodies VEGF, clones VG1 and JH 121. The controls were 10 patients deceased from other causes than ARDS from whom necroptic pulmonary tissue samples.
The ARDS etiology of the studied patients was mainly extrapulmonary (7 cases out of 10). Patients who died because of ARDS had a VEGF pulmonary expression significantly decreased compared to non-ARDS patients: 8.5 (4.1–9.9) versus 28.7 (9.5–48.6) (p < 0.001). (Fig. 1). The seric VEGF levels of ARDS patients were raised (230 pg/ml) compared to non-ARDS patients (131 pg/ml) (p < 0.001). Alveolar macrophages were immunopositive in both groups. No significant statistical differences were noted between the two groups with regard to age, gender, period of ARDS condition, number of ICU days.
A decreased alveolar type II cells, induced by apoptosis was noticed in ARDS evolution, therefore reducing the VEGF production in the alveolar space and also contributing to the decrease in lung perfusion, but also to the consecutive increase of VEGF plasmatic level.
The over-expression of pulmonary VEGF, leads to increased vascular pulmonary permeability and consequently pulmonary oedema. Nevertheless, the VEGF expression in human alveolar epithelial cells also facilitates neovascularization, contributing to endothelial injury repair.Low VEGF pulmonary levels were associated with the severity of ARDS, whereas high VEGF levels were associated with the recovery from ARDS, signalling the role of VEGF in the pulmonary injury repairing process.
Ruxandra Copotoiu, Grant monies (from sources other than industry) The study was supported by National University Research Council (CNCSIS) Grant, Romania, IDEI no 136/2008; No Product/Research Disclosure Information