Plasma myeloperoxidase and vitamin E levels in head injury: preliminary results related to outcome.

This preliminary study was designed to assess a possible role of neutrophil activation and to determine the prognostic value of plasma myeloperoxidase (MPO) and vitamin E (Vit. E) levels in severe head injury. Plasma MPO and Vit. E levels were measured in nine severely head-injured patients (Glasgow Coma Score </=8) (ages 12-80 years) 6, 12. 18, 24, and 30 h after trauma. Patients were classified into two groups according to outcome after discharge from the ICU: group D (death; n = 5) and group S (survival; n = 4). Plasma MPO levels were increased immediately after trauma and then decreased. The MPO peak observed after 6 h was significantly higher (p < 0.05) in group D (mean +/- SEM: 1,237 +/- 122 ng/ml) than in group S (mean +/- SEM: 543 +/- 148 ng/ml). Plasma Vit. E levels were lower than normal values and decreased over time. They were always significantly lower (p < 0.05) in group D than in group S, except for the first sample. These differences cannot be explained entirely by total plasma lipid (TL) values since no statistical difference in TL concentrations was found between the two groups during the course of study. The ratio of Vit. E to TL. considered as the best index of Vit. E status, was lower in group D than in group S. and the difference reached statistical significance (p < 0.05) 12 h after trauma. In conclusion, in spite of the limited number of patients included in this study, it appears that severe head injury is associated with an increase in MPO and a decrease in Vit. E levels. These biochemical changes are of greater magnitude in group D than in group S; they suggest neutrophil activation and lipoperoxidation processes. Finally, plasma MPO and Vit. E seem to be new discriminant factors of outcome in head-injured patients.