[Pathological features of light chain nephropathy].
OBJECTIVE
To investigate the pathologic features and diagnostic algorithm of light chain nephropathy (LCN).


METHODS
Seven cases of LCN were studied by light microscopy, electron microscopy and immunolabeling of light chains (kappa, lambda) by immunofluorescence and immunoelectron microscopy.


RESULTS
The histopathology of 7 cases by light microscopy was variable, with 3 cases showing nodular glomerulosclerosis, 1 case showing mild to moderate mesangial proliferation, and 3 cases showing cast nephropathy with minimal glomerular change. Immunofluorescence study revealed positive staining of a single type of light chain in mesangium (nodular pattern) or along glomerular basement membrane (linear), along tubular basement membrane and around arteriolar walls in all the 7 cases. Ultrastructurally, electron-dense granular deposits were identified in mesangium, subendothelial aspect of glomerular basement membrane, outer aspect of tubular basement membrane and arteriolar walls. Immunogold labeling of light chains showed distinct labeling of a single type light chain in the granular electron-dense materials (5 cases being kappa-positive and 2 being lambda-positive).


CONCLUSIONS
LCN typically shows nodular glomerulosclerosis. The ultrastructural change is characteristic and important for diagnosis. Immunolabeling of light chains by immunofluorescence and immunoelectron microscopy carries further diagnostic value, especially in cases with minimal light microscopic change.
Wang
Su-xia
SX
Department of Electron Microscopy, Peking University First Hospital, Beijing 100034, China.
Zou
Wan-zhong
WZ
Zhang
Ye
Y
Wang
Shu-he
SH
Chai
Li-jun
LJ
Tang
Xiu-ying
XY
D000328:Adult; D000368:Aged; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000276:immunology / Q000473:pathology; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000276:immunology*; D007145:Immunoglobulin kappa-Chains / Q000276:immunology; D007146:Immunoglobulin lambda-Chains / Q000276:immunology; D007674:Kidney Diseases / Q000276:immunology / Q000473:pathology*; D007678:Kidney Glomerulus / Q000276:immunology / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008875:Middle Aged
D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains