ABSTRACT
Acute respiratory distress syndrome [ARDS] is characterized by an extensive alveolar capillary leak, permitting contact between intro-alveolar factors and the endothelium. Von Willebrand Factor antigen [VWF] is a macromolecular antigen that is produced predominantly by endothelial cells and to a lesser extent by platelets. VWF has been investigated as a biological marker of endothelial injury in patients both at risk for and with established ALI/ARDS caused by different etiologies. However, to our knowledge, VWF was not investigated in ALI/ARDS cases caused by poisoning insults. We aimed to investigate VWF as a possible diagnostic, prognostic and predictive marker for ALI/ARDS in poisoned and non-poisoned patients. VWF antigen was measured [By ELISA] in 52 patients with ALI/ARDS, 13 poisoned patients without ALI/ARDS and 20 age and sex matched control subjects. There was a highly significant difference between VWF in patients and control groups [P = 0.001]. Also, VWF level had a significant negative correlation with the ratio between PaO[2] and FIO[2] in patients with respiratory distress. There was a non-significant difference in VWF level between poisonous and non-poisonous cases. There was a significant relationship between the level of VWF and the severity of poisoning in patients with respiratory distress. Among cases of ALI/ARDS caused by different poisoning insults, the highest level of VWF was observed in patients with anticholinesterase insecticides poisoning [P- 0.05]. The difference between VWF level in poisoned patients with ALI/ARDS and those without was highly significant [P- 0.001]. The level of VWF didn't affect patients' need for mechanical ventilation or their mortality. The cut-off value of VWF at 100% sensitivity and 20% specificity was 0.99 units, while the cut-off value of VWF at 100% specificity and 60% sensitivity was 1.87 units. VWF had a diagnostic value for ALI/ARDS but it did not predict the outcome of the illness. Its level did not differ between ALI/ARDS cases due to poisoning versus non-poisoning etiologies. Among cases of ALI/ARDS caused by different poisoning insults, those with anticholinesterase insecticides poisoning showed the highest VWF levels