PMC9841270_01
Second kidney biopsy. (A) Glomerulus with mesangial proliferation (periodic acid-Schiff). (B-E) Granular mesangial and capillary wall staining with IgG kappa and C3 and negative lambda. (F-I) IgG subtype staining with IgG3 showing positive staining similar to IgG and kappa and negative IgG1, IgG2, and IgG4. (J) Electron microscopy image showing electron-dense deposits in the mesangial and subendothelial areas (arrows).
gr1.jpg
PMC9841270_01_gr1.jpg
fig1
A second kidney biopsy was performed after this episode (Fig 1).
First kidney biopsy. (A) Glomerulus with mesangial and endocapillary proliferation and early crescent formation (periodic acid-Schiff). (B-D) Granular mesangial and capillary wall staining with IgG, kappa, and C3. (E-F) Pronase immunofluorescence with kappa and lambda light chains demonstrate kappa restriction. (G) Electron microscopy image showing mesangial deposits (arrows).
gr2.jpg
PMC9841270_01_gr2.jpg
fig2
Given the new diagnosis of PGNMID on her current biopsy, her kidney biopsy from 13 years prior was re-evaluated as shown in Figure 2.