STRONGLY ENHANCED SERUM LEVELS OF VASCULAR ENDOTHELIAL GROWTH-FACTOR (VEGF) AFTER POLYTRAUMA AND BURN

Angiogenesis is a key component of the repair mechanisms triggered by tissue injury. Vascular endothelial growth factor (VEGF) is an importa nt mediator of angiogenesis, as it acts directly and specifically on e ndothelial cells. VEGF produced locally in regenerating tissue may spi ll over into the systemic circulation, and measuring levels of circula ting VEGF may allow monitoring of angiogenesis. To determine whether c irculating VEGF is increased after severe injury, we measured concentr ations of VEGF in serial serum samples of 23 mechanical burn patients, 55 patients with multiple trauma and 56 healthy normal controls, usin g a newly established ELISA assay. In burn patients, serum VEGF was in creased on day 1 (369.4 +/- 88.0 pg/ml) and on day 3 (452.0 +/- 65.3 p g/ml), reached highest levels on day 14(1809.5 +/- 239.7 pg/ml) and wa s still elevated on day 21 post-burn 11339.8 +/- 208.7 pg/ml) (mean +/ - SEM, p<0.01), when compared with healthy controls (82.2 +/- 10.8 pg/ ml (mean +/- SEM)). Likewise, in trauma patients, serum VEGF showed a trend towards elevated values on the day of admission (186.9 +/- 43.9 pg/ml) and on day 3 after injury (193.2 +/- 62.1 pg/ml). Thereafter, s erum VEGF increased further (day 7, 507.0 +/- 114.7 pg/ml), peaked on day 14 1742.4 +/- 151.8 pg/ml) and was still elevated on day 21 after injury (693.1 +/- 218.6 pg/ml (mean +/- SEM, p40.01)). No significant correlation was observed between peak serum VEGF and initial severity of mechanical (Injury Severity Score) or burn injury (percentage of bo dy surface burned). However, in both burn and trauma patients, the sub group of patients with uncomplicated healing showed significantly high er increases of serum VEGF than the subgroup who developed severe comp lications during the post-traumatic course, such as sepsis, adult resp iratory distress syndrome or multiple organ failure (p<0.05). Thus, ma rkedly enhanced levels of serum VEGF are present one to three weeks af ter trauma or burn injury. Further, occurrence of severe complications during the post-traumatic period is associated with lesser increases of serum VEGF.