TY - JOUR
T1 - Membranoproliferative glomerulonephritis
T2 - The role for laser microdissection and mass spectrometry
AU - Jain, Deepika
AU - Green, Jamie A.
AU - Bastacky, Sheldon
AU - Theis, Jason D.
AU - Sethi, Sanjeev
PY - 2014/2
Y1 - 2014/2
N2 - Monoclonal gammopathy is increasingly recognized as a common cause of membranoproliferative glomerulonephritis (MPGN); however, establishing this diagnosis can be challenging. We report the case of a 58-year-old asymptomatic woman who presented with proteinuria with protein excretion of 5,000 mg/d, microscopic hematuria, and normal kidney function. Kidney biopsy was consistent with MPGN pattern of injury. Immunofluorescence studies were positive for nonspecific segmental immunoglobulin M (IgM) and C3 staining. Electron microscopy showed subendothelial, subepithelial, and mesangial electron-dense deposits. The workup excluded an infectious or autoimmune disease, but IgG κ monoclonal protein was detected in serum at a concentration of 0.4 mg/dL. Because there was a mismatch between the serum monoclonal protein (IgG κ) and immunofluorescence staining pattern (nonspecific IgM, no light chain restriction), laser microdissection and mass spectrometry were performed on the kidney biopsy tissue. This identified the deposits as monoclonal IgG κ, thereby leading to the diagnosis of monoclonal gammopathy-associated MPGN. Our case emphasizes the importance of searching for an underlying cause of MPGN, reviews the technique of laser microdissection-mass spectrometry, and highlights its application as a pathology tool for the evaluation of monoclonal gammopathy-related glomerulonephritis.
AB - Monoclonal gammopathy is increasingly recognized as a common cause of membranoproliferative glomerulonephritis (MPGN); however, establishing this diagnosis can be challenging. We report the case of a 58-year-old asymptomatic woman who presented with proteinuria with protein excretion of 5,000 mg/d, microscopic hematuria, and normal kidney function. Kidney biopsy was consistent with MPGN pattern of injury. Immunofluorescence studies were positive for nonspecific segmental immunoglobulin M (IgM) and C3 staining. Electron microscopy showed subendothelial, subepithelial, and mesangial electron-dense deposits. The workup excluded an infectious or autoimmune disease, but IgG κ monoclonal protein was detected in serum at a concentration of 0.4 mg/dL. Because there was a mismatch between the serum monoclonal protein (IgG κ) and immunofluorescence staining pattern (nonspecific IgM, no light chain restriction), laser microdissection and mass spectrometry were performed on the kidney biopsy tissue. This identified the deposits as monoclonal IgG κ, thereby leading to the diagnosis of monoclonal gammopathy-associated MPGN. Our case emphasizes the importance of searching for an underlying cause of MPGN, reviews the technique of laser microdissection-mass spectrometry, and highlights its application as a pathology tool for the evaluation of monoclonal gammopathy-related glomerulonephritis.
KW - Membranoproliferative glomerulonephritis
KW - laser microdissection
KW - laser-capture microdissection-mass spectrometry (LCM-MS)
KW - mass spectrometry
KW - monoclonal gammopathy
KW - nephrotic
KW - proteinuria
KW - proteomics
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UR - http://www.scopus.com/inward/citedby.url?scp=84892931387&partnerID=8YFLogxK
U2 - 10.1053/j.ajkd.2013.09.007
DO - 10.1053/j.ajkd.2013.09.007
M3 - Article
C2 - 24145022
AN - SCOPUS:84892931387
SN - 0272-6386
VL - 63
SP - 324
EP - 328
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 2
ER -