Expression patterns of plasma von Willebrand factor and serum interleukin-8 in patients with early-stage severe pulmonary contusion

Abstract

von Willebrand factor (vWF) is only released from endothelial cells and platelets and is an in vivo and in vitro marker of endothelial injury in septic patients with acute lung injury (ALI). Interleukin-8 (IL-8), as a proinflammatory mediator causing recruitment of inflammatory cells, induces an increase in oxidant stress mediators and makes it as a key parameter for localized inflammation. However, it has not been well established whether the level of serum IL-8 is associated with the severity of lung injury and whether it is a prognosis marker for severe lung contusion. This study was to investigate the expression of plasma vWF and IL-8 and their association with the severity and outcomes of severe pulmonary contusion. A total of 63 patients were divided into a severe pulmonary contusion with acute respiratory distress syndrome (ARDS) group and a non-ARDS group, or a survivor group and a non-survivor group, or an injury severity score (ISS) <20 group and an ISS ≥20 group. Another 20 healthy volunteers served as controls. The levels of plasma vWF and serum IL-8 were measured by enzyme-linked immunosorbent assay (ELISA) at 1, 3, 5 and 7 days after injury. The expression patterns of the plasma vWF and serum IL-8 were compared between different groups. The concentrations of plasma vWF and serum IL-8 were significantly increased in all severe pulmonary contusion patients at all time points in comparison with the control group. The concentrations of plasma vWF in patients with ARDS increased during the whole study period, but vWF in patients with non-ARDS increased gradually until day 5 and then decreased at day 7. The concentration of serum IL-8 showed a similar expression pattern in both groups, but the expression increased more significantly in the ARDS group than in the non-ARDS group. Interestingly, both plasma vWF and serum IL-8 levels steadily increased in the non-survivor group. Furthermore, the level of plasma vWF was higher in the ISS≥20 group than in the ISS<20 group. The level of serum IL-8 in the ISS≥20 group was consistently high, while that in the ISS<20 group peaked at day 3 and decreased at day 5. In addition, the level of plasma vWF was positively correlated with platelet count, but negatively correlated with oxygen index. The level of serum IL-8 was positively correlated with white blood cell count and ISS score, and inversely correlated with oxygen index. The elevated levels of plasma vWF and serum IL-8 in severe pulmonary contusion patients reflect the severity of pulmonary injury and patients outcomes, suggesting that the plasma vWF and serum IL-8 are sensitive markers for clinical evaluation of the severity of pulmonary injury and predication of patient prognosis.