[Clinical efficacy and safety of eculizumab in pediatric atypical hemolytic uremic syndrome].

Objective: To evaluate the efficacy and safety of eculizumab (ECZ) in pediatric atypical hemolytic uremic syndrome (aHUS). Methods: A single-center retrospective study was conducted on 11 children with aHUS who received ECZ therapy in the Department of Nephrology, Children's Hospital of Fudan University, between December 2022 and February 2025. The clinical data, including genetic testing results, were collected for analyzing hematological and renal remission, prognosis and adverse events. Results: Among the 11 patients, 6 were male and 5 were female, with age at onset of 2.83 (0.55, 5.75) years. Eight patients had newly diagnosed aHUS, and 3 had relapsed disease. The pathogenic genetic variants were identified in 3 patients. Before ECZ treatment, 8 children required dialysis, including 2 with chronic dialysis. The age at first ECZ administration was 5.03 (0.72, 11.39) years, and the follow-up duration was (15±9) months. All 11 patients achieved complete thrombotic microangiopathy remission, with a time to remission of (36±23) d. In the 11 patients, the estimated glomerular filtration rate at the final follow-up increased by 46 (31, 62) ml/(min·1.73 m2) compared with baseline. The time to achieve normalization of serum creatinine or a ≥25% reduction was 10.0 (5.5, 31.5) d. Plasma exchange or plasma infusion was discontinued in all patients. The 8 patients who required dialysis at baseline successfully discontinued dialysis, and no new dialysis cases occurred. Six patients with negative genetic testing discontinued ECZ without relapse during follow-up. ECZ was well tolerated, with no meningococcal infections reported. Two patients with elevated liver enzymes recovered fully. Conclusions: ECZ demonstrates favorable efficacy and tolerability in pediatric aHUS. The application of ECZ may contribute to improve the prognosis of aHUS.