C1 Esterase Inhibitor Activity Is Reduced in the Acute Phase Following Burn Injury: A Prospective Observational Study

Hereditary angioedema has been attributed to an inherited deficiency of C1 esterase inhibitor that increases vascular permeability. The role of C1 esterase inhibitor in burn patients has not been described previously. In this study, we attempted to identify the relationship between serial changes of C1 esterase inhibitor activity and the clinical course in major burn patients. This study was a single-center, prospective, observational study. C1 esterase inhibitor activity values were serially examined in major burn patients admitted into the burn center from April 2014 to December 2016. Inclusion criteria were age ≥16 years old and %TBSA burned ≥20%. This study included 38 patients with major burn. C1 esterase inhibitor activity after burn dropped acutely on days 1 and 2 but increased immediately until days 3 to 5, after which it continued to gradually increase to above the reference value. C1 esterase inhibitor activity on admission showed significant inverse correlation with the volume of infusion per body weight required in the first 24 hours after injury and %TBSA burned (r = -0.405, P = 0.01; r = -0.375, P = 0.02, respectively). C1 esterase inhibitor activity on admission was significantly lower in the nonsurvivors than in the survivors during the 28-day evaluation period (59% vs 90%, P = 0.01). These findings suggest that C1 esterase inhibitor may play a critical role in regulating vascular permeability in the acute phase following the burn injury.