2009 Volume 22 Issue 1 Pages 6-12
Membranous Nephropathy (MN) is classified as idiopathic or secondary, with the known causes of secondary MN including the following:infections, autoimmune diseases, drug reactions and malignancies. Idiopathic membranous nephropathy (IMN) is more frequently than secondary in Japanese children. We retrospectively reviewed 27 children (20 boys, 7 girls) with membranous nephropathy in our hospital for the period of 1985 to 2005, aged 8.1 +-3.9 years at onset. 17 patients are idiopathic membranous Nephropathy (IMN), 10 patients are hepatitis B virus related membranous nephropathy (HBMN) that is the most causes of secondary MN. In result, urinary abnormalities were detected in 16 patients through school urinary screening, and in other 11 children through chance urinary abnormalities. Six patients had nephrotic syndrome at onset. Electron microscopic staging according to the classification by Ehrenreich and Churg was performed in all patients. IMN consists of stage I in 4, II in 9, and III in 4, while HBMN consist of stage I in 3, II in 6, and III in 4. Oral corticosteroid was given to 17 patients, immunosuppressive therapy with cyclosporin was administered to only one patients. In spite of treatment with corticosteroid or not, almost IMN patients showed complete remission of proteinuria at the follow-up of 10 years, and only one patient had isolated mild hematuria. From these results, we suggest that IMN and HBMN in Japanese children might take a better course and outcome than IMN in adults and non-Japanese children.
