Serum complement 5a and complement 5a receptor-1 levels in children with chronic kidney disease

BACKGROUNDThe complement system plays an active role in renal fibrosis, the primary mechanism of chronic kidney disease (CKD).Recent studies suggest that increased expression of complement 5a (C5a) and C5a receptor-1 (C5aR1) stimulates renal fibrosis.AIM To investigate the potential roles and relationships of complement C5a and C5aR1 in children with CKD.METHODS This cross-sectional study included 76 children with CKD and 24 healthy controls.Laboratory data including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), C3, and C4 were recorded.Serum C5a and C5aR1 levels were measured using ELISA.Comparisons were performed using Student's t-test and one-way analysis of variance; relationships were evaluated via Pearson correlation analysis.RESULTS Serum C3 levels were significantly lower in children with CKD than in controls, whereas serum C4 levels were significantly higher specifically in stage 5 patients.Serum C5a values trended higher in stage 5 CKD compared with earlier stages, although this did not reach statistical significance.Conversely, serum C5aR1 levels did not differ significantly across CKD stages or etiologies.However, among stage 5 patients, those undergoing peritoneal dialysis exhibited significantly higher C5a and C5aR1 levels than those on hemodialysis.Pearson correlation analysis demonstrated a statistically significant, moderate positive relationship between serum C5a and C5aR1 Levels (r = 0.489, P = 0.01).4 / 26 CONCLUSION The moderate positive correlation between C5a and C5aR1 suggests a potential ligandinduced receptor upregulation mechanism in vivo.Although serum C5aR1 levels alonemay not constitute a direct risk factor for CKD, they might be linked to chronic inflammation, suggesting potential correlations with complement components and inflammatory markers.These findings could provide insights into complementmediated mechanisms, potentially paving the way for alternative therapeutic strategies.