results in predominant C3 without significant Ig deposition on immunofluorescence microscopy and characteristic sausageshaped, wavy deposits by electron microscopy within the glomerulus. Disease clinically presents as proteinuria, hematuria, acute nephritis or nephrotic syndrome and acute kidney failure. We are presenting an 8 years old boy that was brought to the clinic because of macroscopic hematuria. At initial presentation he had high blood pressure and periorbital edema. Urinalysis

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... d numerous erythrocytes, proteinuria and presence of casts in the urine. Creatinine and urea concentration was elevated with low serum protein and albumin. No pleural or pericardial effusion was found. Urine culture was sterile and urinary tract ultrasound did not show anatomical anomalies or urolithiasis. He had proteinuria of 1,69 g/24h (74,2 mg/m2/h) and albuminuria of 1096 mg/24h. Glomerular hematuria was confirmed with the finding of 100% dysmorphic erythrocytes in the urinary sediment. Serum C3 concentration was low with normal C4. In accordance with anamnestic data on febrile sore throat 2 weeks prior to hospitalization, the antistreptolysin titre was slightly elevated. Immunological screening excluded lupus nephritis (negative ANA and ANCA), and serological examinations excluded hepatitis C and B. The patient was treated with oral antimicrobial course, fursemide and amlodipine, regulated diet. Repeated serum creatinine and urea concentrations were being improved and lastly were normalized during outpatient monitoring. Constant recovery of proteinuria and albuminuria was being observed and microscopic hematuria resolved after 4 months. Low C3 concentration persisted for another 2 months. Renal biopsy revealed focal endocapillary proliferative glomerulonephritis (GN) and GN with the dominant C3 finding on the light and immunofluorescence microscopy that may suits postinfective GN as well as C3 glomerulopathy. Electron microscopy showed a finding which is in accordance with DDD. Additional testing revealed decreased classical (43 CH50/ml; ref. range 48-103 CH50/ml) and deficient alternative (3%; ref. range 70-125%) pathway activity as well as slightly positive C3NeF, supporting the diagnosis of DDD. Genetic analysis revealed a polymorphism of the complement factor H gene with an increased risk of developing DDD. The child was fully recovered after supportive therapy. After a follow-up period of 2 years patient remained asymptomatic with normal kidney function. Given the poor prognosis of the disease, the proper approach to such specific glomerulopathy is important to avoid or at least to slow the progression to end-stage renal disease.