Evaluation of complement system in children with Crimean-Congo hemorrhagic fever.

OBJECTIVES The complement system participates in the defense of the body against viral infections through various mechanisms. In the present study conducted on children having Crimean-Congo Hemorrhagic Fever (CCHF), the aim was to evaluate whether the complement system had a role in the pathogenesis of the disease. PATIENTS AND METHODS Forty-one patients diagnosed with CCHF and 32 healthy controls were included in the study. Serum complement component 3 (C3), 4 (C4) and complement product Bb (Bb) levels were measured in both groups. RESULTS Compared to the control group, serum C3 levels were lower and Bb levels were higher in CCHF patients (p < 0.01). Moreover, in the patient group, C3 levels were positively correlated with WBC and PLT counts, and Bb levels were positively correlated with AST, ALT and LDH activities. In the patient group, serum Bb levels were negatively correlated with WBC and PLT counts. CONCLUSIONS The results of the present study suggest that increased activity of the alternative pathway of the complement system in children with CCHF may have a role in the pathogenesis of the disease.