RESUMO
The activation of the complement system in pediatric patients with congestive heart failure [CHF] still remains unclear. The objective of this study was to measure the serum levels of terminal complement complex [C5b-9] to determine its predictive value for the prognosis in children with CHF, and to correlate these levels with clinical and echocardiographic assessment of heart failure. Forty cardiac patients with CHF, with a mean age of 5.2 years, were enrolled in the study. According to Ross classification of CHF, they were classified as: Ross class II [12 patients], class III [13 patients], and class IV [15 patients]. Twenty healthy children served as a control group. Serum C5b-9 was assessed with Enzyme lmmunoassay and serum tumor necrosis factor- alpha [TNF- alpha] was measured using ELISA kits. Echocardiographic assessment of left ventricular systolic and diastolic functions was performed. Clinical outcomes were determined at follow-up period of 6months [death or major adverse cardiac events]. The results showed that serum C5b-9 [and also serum TNF- alpha] were significantly higher in patients with CHF as compared to controls [P<0.001] and increased with the severity of the disease, with the highest levels in Ross class IV children and in patients with adverse clinical outcomes by 6 months [P<0.001]. there were significant positive correlations between Ross class of CHF and serum c5b-9 levels, and significant negative correlations between echocardiographic parameters of ventricular function and C5b-9 levels [P<0.001]. Serum C5b-9 [the terminal complement complex] is significantly elevated in children with CHF, increasing with the severity of the disease, and it is a prognostic predictor of adverse clinical outcome. Complement may be a novel target for therapeutic intervention with specific complement inhibitors in patients with CHF