A case of de novo glomerulonephritis with electron-dense deposits following renal transplantation

We present here a case of de novo glomerulonephritis (GN) twoyr after kidney transplantation. The patient was a 13-yr-old girl who had renal insufficiency because of bilateral hypoplastic kidneys. She received a renal allograft from her father at the age of 11yr. Immunosuppressive treatment was started with tacrolimus, mizoribine (MZB), basiliximab, and methylprednisolone (mPSL). There were no findings of GN at the one-h biopsy (first biopsy). Two yr after transplantation, she showed proteinuria, hematuria and increased serum creatinine level with no apparent trigger. The biopsy specimen (fourth) showed mesangial proliferative GN with electron-dense deposits in a variety of regions and borderline changes indicating acute rejection. She was treated with mPSL pulse therapy, deoxyspergualin, replacement of MZB with mycophenolate mofetil, an increase of the mPSL dose, and candesartan. Her serum creatinine and urinary protein excretion levels improved after the treatment. Onemonth later, she developed deterioration in her renal function again. Renal biopsy findings (fifth) were almost the same as the lesions observed in the fourth allograft biopsy. After she recovered from these episodes, she appeared to improve in clinical findings of GN. Protocol biopsies at threeyr and fivemonths after transplantation (sixth) showed no evidence of acute rejection, but we still observed the features of de novo GN. We could not resolve the underlying causes by reference to the clinical history and serological findings. We speculate that some kind of immunological reactions might be associated with the pathophysiology.