The role of С1 esterase inhibitor in the pathogenesis of pertussis

Introduction. Pertussis is an acute infectious disease characterized by paroxysmal cough, edematous syndrome, specific hematological changes, and the development of secondary immunodeficiency. The appearance of characteristic syndromes in pertussis is associated with the functioning of the kallikrein-kinin system and its key protein, C1-esterase inhibitor (C1-INH).

Objective. To clarify the role of C1-esterase inhibitor in the pathogenesis of pertussis by determining its serum levels in children with pertussis, stratified by disease severity and age.

Materials and Methods. The study enrolled 117 children. Patients were divided into 3 groups: 1) children with severe pertussis; 2) children with moderate pertussis; 3) children with acute respiratory infections (ARI). The age of the examined children ranged from 1 month to 17 years inclusive. Serum C1-INH levels were determined using enzyme-linked immunosorbent assay (ELISA).

Results. Children with severe pertussis exhibited higher mean C1-INH levels (30.8 ± 4.7 mg/dL) compared to those with moderate pertussis (24.3 ± 3.4 mg/dL) and significantly exceeded the levels in patients with ARI (14.6 ± 4.6 mg/ dL; p=0.04). Infants with pertussis under one year of age, regardless of disease severity, had significantly higher C1-INH levels compared to children from older age groups. Analysis of the relationship between age and serum C1-INH levels in children with pertussis revealed a statistically significant inverse correlation (r = -0.24, p=0.02): the younger the child with pertussis, the higher the C1-INH level. In contrast, no such age-related correlation was observed in the comparison group of children with ARI (r = -0.14, p=0.4).

Conclusion. Assessment of C1-INH levels in children, depending on age and severity of the disease, is important to clarify its role in the pathogenesis of whooping cough and to develop new treatment methods. Further research is warranted.

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