Case. A 14-year old girl with fever, macroscopic hematuria, oliguria, and acute kidney injury (AKI) was admitted to our clinic. The medical history revealed that the patient had undergone several cardiac interventions due to truncus arteriosus type 1, and she recovered from IE-induced glomerulonephritis following antibiotherapy six months ago. During admission, the patient was diagnosed with IE according to one major (positive imaging finding) and three minor (fever, predisposing cardiac disease, and immunological criterion) criteria. Immediate antibiotic treatment was initiated. A kidney biopsy was performed, which showed crescentic glomerulonephritis (CGN with crescents, >50%). Daily pulse steroid (3 days), monthly pulse cyclophosphamide (6 doses), and oral steroid (2 mg/kg/day) therapy were initiated with gradual dose tapering. The patient underwent 12 hemodialysis sessions until the 38^th day of the treatment. She was discharged on the 45th day of treatment with normal kidney function tests and negative acute phase reactants. Treatment was maintained with mycophenolate mofetil (MMF) after a 6-month course of cyclophosphamide. MMF was discontinued in the 12th month. At the 18thmonth follow-up visit the patient had mild proteinuria, and was on ramipril therapy.

Conclusions. The occurrence of CGN should be considered in children with predisposing cardiac disease, who develop hematuria, proteinuria, and severe AKI. Although antibiotic therapy alone is often sufficient in this immune complex GN induced by infection, early initiation of additional immunosuppressive therapy in the presence of CGN may be beneficial for long term preservation of kidney functions. Keywords : infective endocarditis, crescentic glomerulonephritis, children, vegetation