Coexistence of Anti-Glomerular Basement Membrane Glomerulonephritis and Membranous Nephropathy in a Female Patient with Preserved Renal Function

Coexistence of Anti-Glomerular Basement Membrane Glomerulonephritis and Membranous Nephropathy in a Female Patient with Preserved Renal Function

AOI OGAWARA,^1,2 MAKOTO HARADA,^1,3 TOHRU ICHIKAWA,¹ KAZUAKI FUJII,^1,3 TAKASHI EHARA⁴ and MAMORU KOBAYASHI¹

¹Department of Nephrology, Nagano Red Cross Hospital, Nagano, Nagano, Japan
²Department of Emergency and Critical Care Medicine, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
³Department of Nephrology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
⁴Graduate School of Health Sciences, Matsumoto University, Matsumoto, Nagano, Japan

Renal prognosis for anti-glomerular basement membrane (GBM) glomerulonephritis is poor. The greater the amount of anti-GBM antibody binding the antigen (type IV collagen of the glomerular basement membrane), the greater the number of crescents that develop in glomeruli, resulting in progression of renal impairment. Immunofluorescence staining reveals linear IgG depositions on glomerular capillary walls. Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in middle-aged to elderly patients. Immune complex is deposited in the sub-epithelial space of the glomerulus resulting in the development of a membranous lesion. Immunofluorescence staining reveals granular IgG depositions on glomerular capillary walls. Coexisting anti-GBM glomerulonephritis and MN are rare and, here we report a case of coexisting anti-GBM glomerulonephritis and MN with preserved renal function. There are some cases of coexisting anti-GBM glomerulonephritis and MN do not show severely decreased renal function. A 76-year-old Japanese woman presented with nephrotic syndrome, microscopic hematuria, and was positive for anti-GBM antibody. Kidney biopsy revealed linear and granular IgG depositions in glomerular capillary walls, crescent formations, and electron-dense deposits in the sub-epithelial space. She was diagnosed with anti-GBM glomerulonephritis and MN. Steroid and cyclosporine therapy achieved complete remission, and kidney function was preserved. In conclusion, coexisting anti-GBM glomerulonephritis and MN can have preserved renal function. IgG subclass of deposited anti-GBM antibody may be associated with the severity of anti-GBM glomerulonephritis. In addition, in the case of nephrotic syndrome with hematuria, we should consider the possibility of coexisting anti-GBM glomerulonephritis and MN.

keywords —— anti-glomerular basement membrane glomerulonephritis; hematuria; linear and granular IgG depositions; membranous nephropathy; nephrotic syndrome

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Tohoku J. Exp. Med., 2017, 243, 335-341

Correspondence: Makoto Harada, M.D., Ph.D., Department of Nephrology, Nagano Red Cross Hospital, 5-22-1 Wakasato, Nagano, Nagano 380-8582, Japan.

e-mail: tokomadaraha724@gmail.com