case_images: PMC11825443_01
case_images: Renal pathology results of the patient in the case report. (A,B) The glomeruli exhibit mesangial and endocapillary hypercellularity (scale bar 50 mum). (C) Eosinophilic material deposits are visible in the subepithelial, subendothelial, and mesangial areas (scale bar 50 mum). (D) The basement membrane is thickened, showing a diffuse double-contour structure (scale bar 50 mum). (E) Moderate to severe proliferation and extensive lobulation in mesangial cells and matrix, along with a segmental increase in intracapillary cells (scale bar 4 mum). (F) Transmission electron microscopy revealed moderate to severe mesangial cell and matrix hypercellularity, with red arrows indicating subendothelial electron-dense deposits and widespread interposition (scale bar 2 mum). (G) Transmission electron microscopy showed segmental capillary lumen cellularity, with red arrows indicating mesangial electron-dense deposits, significant basement membrane thickening, and double contours (scale bar 2 mum). (H) Increased lysosomes were observed in proximal tubular epithelial cells, with red arrows pointing to the areas of lysosome accumulation (scale bar 2 mum). (I) Ig Kappa staining revealed electron-dense deposits in the mesangial and subendothelial regions of the glomeruli (scale bar 1 mum). (J) Ig Kappa staining revealed electron-dense deposits in the proximal tubular epithelial cells (scale bar 1 mum). (K) Ig Lambda staining reveals the absence of electron-dense deposits in the glomeruli (scale bar: 1 mum). (L) Ig Lambda staining also indicates no electron-dense deposits in the proximal tubular epithelial cells (scale bar: 1 mum).
case_images: fmed-12-1502798-g001.jpg
case_images: PMC11825443_01_fmed-12-1502798-g001.jpg
case_images: fig1
case_images: HE staining indicated mesangial and endothelial cell proliferation (Figures 1A,B). Masson's trichrome staining highlighted eosinophilic deposits in various glomerular regions (Figure 1C), which tested negative for Congo red staining, indicating non-amyloid material. PASM staining demonstrated basement membrane thickening and diffuse double contours (Figure 1D). Electron microscopy confirmed membranoproliferative glomerulonephritis (MPGN) and revealed an accumulation of lysosomes in tubular epithelial cells (Figures 1E-H) while immunoelectron microscopy identified kappa electron-dense deposits predominantly in subendothelial and mesangial areas of the glomeruli as well as within tubular cell lysosomes (Figures 1I,J). Lambda deposits were not observed (Figures 1K,L).
case_images: Changes in (A) serum creatinine (mumol/L), (B) estimated glomerular filtration rate (mL/min/1.73m2), (C) serum albumin (g/L) and (D) 24-h urinary protein quantification (g) during the 270 days of treatment and follow-up. Rb, rituximab; VCD, bortezomib, cyclophosphamide, dexamethasone.
case_images: fmed-12-1502798-g002.jpg
case_images: PMC11825443_01_fmed-12-1502798-g002.jpg
case_images: fig2
case_images: By day 270, urinary protein levels had decreased dramatically from 6.492 g/24 h to 1.056 g/24 h, and serum creatinine levels fell from 205.5 mumol/L to 98.5 mumol/L (Figures 2A-D).