Proliferative glomerulonephritis with discrete deposition of monoclonal immunoglobulin γ1 CH 2 heavy chain and κ light chain: a new variant of monoclonal immunoglobulin deposition disease.
A 45-year-old man presented with moderate proteinuria and hematuria. A renal biopsy showed mesangial/endocapillary proliferative glomerulonephritis, linear deposition of monoclonal immunoglobulin γ1 C(H) 2 heavy chain along glomerular and tubular basement membranes (GBMs and TBMs), granular deposition of κ light chain within the mesangial area, and continuous linear deposits of finely granular electron-dense materials along GBMs and TBMs. Dual immunostaining showed essentially discrete glomerular localization of γ1 C(H) 2 heavy chain and κ light chain. Monoclonal protein was not detected in urine and serum. A bone marrow aspiration showed no abnormalities. Steroid therapy led to the improvement of proteinuria and hematuria. We would classify this case as a new variant of monoclonal immunoglobulin deposition disease, light chain/heavy chain deposition disease. In contrast with light and heavy chain deposition disease, the remarkable characteristics of this variant are separate deposition of monoclonal heavy chain and light chain, deposition of largely deleted γ heavy chain lacking the C(H) 1 domain, and good response to steroid therapy.
Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Japan. komatsud@med.akita-u.ac.jp
Atsushi
A
Komatsuda
Hiroshi
H
Ohtani
Kenichi
K
Sawada
Kensuke
K
Joh
Hideki
H
Wakui
D057911:Angiotensin Receptor Antagonists / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D049109:Cell Proliferation; D050533:Glomerular Basement Membrane / Q000378:metabolism / Q000648:ultrastructure; D015432:Glomerulonephritis, Membranoproliferative / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007142:Immunoglobulin gamma-Chains / Q000276:immunology* / Q000378:metabolism; D007145:Immunoglobulin kappa-Chains / Q000276:immunology* / Q000378:metabolism; D007678:Kidney Glomerulus / Q000378:metabolism / Q000473:pathology; D007684:Kidney Tubules / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D011239:Prednisolone / Q000627:therapeutic use; D016896:Treatment Outcome
D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D015415:Biomarkers; D005938:Glucocorticoids; D007142:Immunoglobulin gamma-Chains; D007145:Immunoglobulin kappa-Chains; D011239:Prednisolone