C3 glomerulopathy: experience of a pediatric nephrology center

Background: C3 glomerulopathy (C3G) is an uncommon disease characterized by the deposition of complement factors in the glomeruli due to overactivation and dysregulation of the alternative pathway of complement.Objectives: This study aimed to describe the clinicopathological features, laboratory testing, clinical course, treatment, and outcomes of pediatric patients with C3G.Patients and Methods: We reviewed retrospectively the laboratory testing, kidney biopsy reports, and clinical features of 18 patients at our hospital from 2007 to 2019.Results: There were 18 cases, and the majority of the patients were girls (61.1%). The mean age at diagnosis was 11.3 ± 3.7 (5-17) years, and nephritic-nephrotic syndrome presentation in patients was more common (11 cases, 61.1%). Hematuria was found in 66.7% of the patients, of which the majority had microscopic hematuria (58.3%). Hypertension was observed in 10 (55.6%) patients. The mean glomerular filtration rate (eGFR) was 95.7 ± 47.3 mL/min/1.73 m², and 24-h urinary protein excretion was 76.2 ± 48.6 mg/m²/h. Sixteen patients (88.9%) received renin-angiotensin-aldosterone system blockers (RASB), and two of them were taking RASB only. The majority of patients (83.3%) were treated with immunosuppressive therapy. Eculizumab was also given to one of them. At the last follow-up, two patients had levels of less than 60 mL/min/1.73 m² for eGFR. Seven patients with immunosuppressive treatment achieved complete remission.Conclusion: C3G shows a variable clinical presentation and response to immunosuppressive therapy. In the present study, we observed that the most common presentation was nephritic and/or nephrotic syndrome and partially responded to treatment to RASB and immunosuppressants.