Study of complement activation, C3 and interleukin-6 levels in burn patients and their role as prognostic markers

Abstract

Purpose: The management of burn patients is always challenging for the clinician due to high risk of bacterial sepsis, multi-organ failure and death. Our objective was to study complement activation, C3 and interleukin-6 (IL-6) levels in burn patients and evaluate their role as prognostic markers. Materials and Methods: A total of 63 burn patients and 60 healthy controls were included in this study. Blood was collected from patients within 24 h and at 7th day of injury. Complement activation was determined by crossed electrophoresis and counter-current immunoelectrophoresis. C3 levels were measured using a single radial immunodiffusion. IL-6 was detected by ELISA. Results: All patients showed initial complement activation. Mean C3 levels showed an inverse correlation with the severity of burn. Patients with ≥20% burns had lower C3 than the controls (P < 0.001) and those with <20% burns (P < 0.001). Patients with ≥40% burns had activated complement and low C3 in 2nd week; they subsequently developed infection. Complement was inactive and C3 levels recovered in patients with <40% burns. The non-survivors showed significantly lower C3 than the survivors (P < 0.05) in 2nd samples. Patients who developed infection had C3 significantly lower than those who remained free of infection (P < 0.05). All patients showed initial elevation in IL-6 levels. Patients with ≥60% burns had significantly higher IL-6 than controls (P < 0.001) and those with <60% burns (P < 0.001). Non-survivors had higher IL-6 than survivors in both samples (P < 0.001). Patients who developed infection showed significantly higher IL-6 in 2nd samples than those without infection (P < 0.001). Conclusions: Complement activation, C3 and IL-6 levels correlated well with the severity of injury and development of infection in burn patients. These parameters can be used to predict the onset of infection, septicaemia and mortality in burn patients.