Clinical Characteristics of 30 Cases of Childhood Haemolytic Uremic Syndrome in a Single Centre

ABSTRACT Aim To analyse the clinical characteristics of 30 children with haemolytic uremic syndrome (HUS) to enhance understanding, improve early diagnosis and explore prognostic strategies. Methods A retrospective analysis was conducted on 30 HUS cases admitted to the nephrology department of Beijing Children's Hospital from 1 September 2020 to 30 April 2023. Clinical data, including laboratory results (with emphasis on haptoglobin levels and complement factors), kidney biopsy findings, genetic testing, treatment regimens (detailed dosages and courses) and follow‐up outcomes, were manually extracted and verified by researchers. Efficacy was evaluated by haematological and kidney function recovery, and follow‐up assessed remission, recurrence and chronic kidney disease (CKD) progression, with clear differentiation between dialysis dependence and CKD Stage 5. Results Aetiologies included secondary HUS (11 cases, mainly systemic lupus erythematosus, diagnosed after excluding other subtypes), cobalamin C deficiency (4 cases) and atypical HUS (aHUS, 15 cases). Most (63.3%) were over 6 years old, with a female predominance (male:female ratio 1:1.5). Common manifestations included nephrotic syndrome (73.3%), acute kidney injury (40% at Stage 3) and low complement C3 (90%). Haptoglobin levels were decreased in 89.3% of tested cases. Secondary HUS showed lower platelet counts (60.5 × 10 9 /L vs. 135.9 × 10 9 /L) and higher lactate dehydrogenase levels (1078.4 vs. 784.8 U/L) than aHUS ( p < 0.05), likely due to concurrent autoimmune‐mediated tissue damage. Treatment included plasma exchange, complement C5 inhibitors (eculizumab/crovalimab with specified dosages) and disease‐specific therapies, with 60% complete remission. Follow‐up revealed three cases of CKD Stage 5: one patient with dialysis dependence for < 3 months, one patient with dialysis dependence for > 3 months and one patient who received kidney transplantation (one additional patient underwent kidney transplantation independently of CKD Stage 5). Conclusion Childhood HUS in this cohort is dominated by aHUS and secondary types. Early etiological differentiation, comprehensive laboratory assessment and targeted therapy improve outcomes, with findings aligning with global data but showing a more pronounced female bias due to high SLE‐related cases.