title: Membranous nephropathy associated with thyroid-peroxidase antigen.
abstract: A 6-year-old previously healthy Japanese girl was found to have dipstick 2+ proteinuria and a goiter based on the results of a routine school medical examination. Her serum free-thyroxine level was 4.98 ng/dL (normal range 0.95-1.74 ng/dL), thyroid-stimulating hormone (TSH) was less than 0.003 microU/mL (0.34-3.88 microU/mL), anti-microsomal (anti-thyroid-peroxidase) antibody was 1600 T (up to 100), anti-thyroglobulin antibody was 400 T (up to 100), and TSH-receptor antibody was 84% (up to +/-10%). These results are consistent with a diagnosis of Graves' disease. Electron microscopy examination of a renal biopsy specimen revealed electron-dense deposits located in the subepithelial spaces, and immunofluorescence microscopy examination demonstrated bright granular stainings of immunoglobulin G along the glomerular capillary walls. These findings are characteristic of membranous nephropathy. To investigate the relationship between the membranous nephropathy and Graves' disease, we carried out a second immunofluorescence study, which revealed that the immunoglobulin G granular deposits corresponded to glomerular granular staining of thyroid-peroxidase, whereas staining for thyroglobulin was absent. It was therefore assumed that the deposition of immune complexes mediated by thyroid-peroxidase had caused the membranous nephropathy in this patient. This is the first report of membranous nephropathy associated with Graves' disease in which deposits of thyroid-peroxidase, rather than thyroglobulin, have been confirmed in the kidney.
authors.affiliation: Department of Pediatrics, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shima
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Togawa
authors.forename: Mina
authors.initials: M
authors.lastname: Obana
authors.forename: Mayumi
authors.initials: M
authors.lastname: Sako
authors.forename: Masakazu
authors.initials: M
authors.lastname: Miyawaki
authors.forename: Kandai
authors.initials: K
authors.lastname: Nozu
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Iijima
authors.forename: Norishige
authors.initials: N
authors.lastname: Yoshikawa