title: Simultaneous occurrence of fibrillary glomerulonephritis and renal lesions in nonmalignant monoclonal IgM gammopathy.
abstract: BACKGROUND
  Fibrillary glomerulonephritis (FGN) is a rare primary glomerular disease that seldom coexists with other diseases. Membranoproliferative glomerulonephritis is a pathologic finding of renal lesions associated with IgM-secreting monoclonal proliferations. We present a case study of a patient with unusual simultaneous FGN and IgM-related renal disorder in nonmalignant monoclonal IgM gammopathy.
  
  
  METHODS
  A 63-year-old male presented with nephrotic syndrome and elevated serum creatinine levels. Laboratory examination revealed elevated levels of serum IgM and low C3 levels. Serum and urine immunofixation electrophoresis showed a monoclonal IgM with a kappa light chain. A bone marrow biopsy revealed less than 5 % bone marrow infiltration by lymphoplasmacytic lymphoma, and a renal biopsy revealed mesangiocapillary glomerulonephritis on light microscopy. Immunofluorescent and immunohistochemical staining indicated granular deposits of immunoglobulin G in the mesangium and granular deposits of immunoglobulin M and κ light chains along the capillary wall. Electron microscopy revealed randomly arranged nonbranching fibrils of approximately 15 nm in diameter in the glomerular mesangium and subendothelial electron-dense deposits. According to these results, we confirmed FGN and membranoproliferative glomerulonephritis, which were attributed to monoclonal IgM deposits.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report of simultaneous FGN and membranoproliferative glomerulonephritis in nonmalignant IgM monoclonal gammopathy.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, 95,Wen Chang Rd., Shih Lin District, Taipei, 11101, Taiwan.|Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chung-Kuan
authors.initials: CK
authors.lastname: Wu
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, 95,Wen Chang Rd., Shih Lin District, Taipei, 11101, Taiwan.|School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan.
authors.forename: Jyh-Gang
authors.initials: JG
authors.lastname: Leu
authors.affiliation: Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: An-Hang
authors.initials: AH
authors.lastname: Yang
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.|Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Der-Cherng
authors.initials: DC
authors.lastname: Tarng
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, 95,Wen Chang Rd., Shih Lin District, Taipei, 11101, Taiwan.
authors.forename: Hsiang-Yuen
authors.initials: HY
authors.lastname: Tung
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, 95,Wen Chang Rd., Shih Lin District, Taipei, 11101, Taiwan. shoushan.chiang@gmail.com.
authors.forename: Shou-Shan
authors.initials: SS
authors.lastname: Chiang
mesh_terms: D005921:Glomerulonephritis / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D015432:Glomerulonephritis, Membranoproliferative / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000097:blood / Q000150:complications*; D009404:Nephrotic Syndrome / Q000209:etiology
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M