A patient with severe renal amyloidosis associated with an immunoglobulin gamma-heavy chain fragment.
The authors report a patient with progressive renal dysfunction caused by severe renal amyloidosis associated with a gamma-heavy chain variable region (V(H)) fragment. The patient was a 71-year-old woman who had renal insufficiency without nephrotic syndrome. Laboratory data showed a monoclonal IgG lambda component in her serum and urine. Renal biopsy results showed massive amyloid deposition in the mesangial region, but the glomerular basement membranes and epithelial cells were preserved. Because immunohistochemical studies using antibodies against a number of known amyloid fibril proteins failed to detect the amyloid protein, the amyloid protein extracted from a small piece of the biopsied renal tissue was subjected to biochemical analysis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the extracted amyloid protein showed a prominent band at 11-kDa, and this protein was identified by amino acid sequence analysis as a gamma-heavy chain variable region fragment (V(H)3 subgroup) without the first N-terminal residue. Our results indicate that the patient's renal amyloidosis was associated with a gamma-heavy chain variable region fragment. Microextraction and biochemical characterization of amyloid fibrils was of great use for reaching a definitive diagnosis.
Yazaki
Masahide
M
Third Department of Medicine, Research Center on Aging and Adaptation, Shinshu University School of Medicine, Matsumoto, Japan. mayazaki@hsp.md.shinshu-u.ac.jp
Fushimi
Tomohisa
T
Tokuda
Takahiko
T
Kametani
Fuyuki
F
Yamamoto
Kanji
K
Matsuda
Masayuki
M
Shimojo
Hisashi
H
Hoshii
Yoshinobu
Y
Higuchi
Kei-ichi
K
Ikeda
Shu-ichi
S
D000368:Aged; D000686:Amyloidosis / Q000175:diagnosis / Q000276:immunology*; D005260:Female; D006362:Heavy Chain Disease / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007142:Immunoglobulin gamma-Chains / Q000302:isolation & purification; D007674:Kidney Diseases / Q000175:diagnosis / Q000276:immunology*
D007142:Immunoglobulin gamma-Chains