Résumé
Objective To analyze the clinical characteristics of 7 pediatric patients with C3 glomerulonephritis (C3-GN).Methods The clinical manifestations,pathological features,therapies,prognosis of patients from Jun.2006 to Nov.2011 were analyzed retrospectively.Results All of the patients were presented as acute nephritic syndrome,and 4 patients with macroscopic hematuria,other 3 cases with severe proteinuria.Five patients with eyelid edema.All the patients showed decreased level of serum complement C3,while serum complement C4 was normal.Investigations showed elevation of 24 h urine protein,5 patients with elevated antistreptolysin O titers.Three patients with renal dysfunction.Isolated C3 deposition in mesangial and endothelial areas(+ +-+ + +) was confirmed by immunofluorescence.Light microscope revealed membrane proliferative glomerulonephritis and mesangial proliferative glomerulonephritis.Electron microscope showed swelling and hyperplasia of endothelial cells without electron-dense deposition or podocyte foot fusion.Based on conventional treatment,administration of immunosuppressant was performed in 3 patients with severe pathological changes.After a follow-up of 2 months to 5 years,the prognosis seems to be benign.Conclusions Children with C3-GN are usually presented as acute nephritic syndrome,characterized by isolate C3 deposition in immunofluorescence.Electron microscope showed lesion of endothelial cells,while no electron-dense deposits in mesangial and endothelial areas.The mechanism may be associated with dysregulation of alternative complement pathway,and seems had a good short-term prognosis.