The role of Interleukin-6, its −174 G>C polymorphism and C-reactive protein in idiopathic cardiac arrhythmias in children

Knowledge about the role of inflammation in the pathogenesis of arrhythmias in children is limited. Several studies have suggested a relationship between plasma IL-6 levels and/or the −174G>C IL-6 gene polymorphism and atrial fibrillation in adults. Our present study was performed to investigate whether serum IL-6, −174G>C IL-6 polymorphism and C-reactive protein (CRP) are associated with arrhythmias of unknown origin in children. The study included 126 children diagnosed with supraventricular or ventricular arrhythmia. Patients with congenital heart defects as well as arrhythmias of known origin were excluded from the study. The control group comprised 37 healthy children. The 24 hour Holter electrocardiography monitoring was performed. Serum IL-6, −174 GC IL-6 polymorphism and CRP concentrations were measured on admission. There were no differences in IL-6, CRP and −174 G>C IL-6 genotype distribution between the control and patient groups. No significant differences in IL-6, CRP and −174 G>C IL-6 genotypes were observed between children with supraventricular or ventricular arrhythmias. The severity of arrhythmias showed also no associations with IL-6, CRP or −174 G>C IL-6 genotypes. The results suggest that idiopathic cardiac arrhythmias of unknown origin in children are not associated with selected pro-inflammatory markers of infections i.e. elevated IL-6, CRP or −174 G>C IL-6 polymorphism. This new information can effectively reduce the total financial cost of unnecessary diagnosis and treatment of children affected by cardiac arrhythmias.