case_images: PMC11303131_01
case_images: (A-F) Images from the renal biopsy. (A) Light microscopy exhibits a membranoproliferative GN pattern of injury (periodic acid-Schiff stain, 400x). (B) Direct immunofluorescence study shows bright granular IgG. (C) Bright granular IgG3. (D) Bright kappa. (E,F) Ultrastructure showed segmental thickening of the glomerular basement membrane, diffuse fusion of pedicles, segmental tethered insertion, and deposition of electron dense material in the subendothelial and tethered areas.
case_images: fmed-11-1360979-g001.jpg
case_images: PMC11303131_01_fmed-11-1360979-g001.jpg
case_images: fig1
case_images: IgG, and kappa light chain in the glomerular mesangium. IgG subclass staining suggested strongly positive staining for IgG3 and weak to negative staining for IgG1, IgG2, IgG4, and lambda light chain (Figure 1). Ultrastructural analysis revealed segmental thickening of the glomerular basement membrane, with diffuse pedicle fusion, segmental tethered insertion, subendothelial deposits, and electron-dense materials in the tethered areas (Figure 1).
case_images: B-cell subset immunophenotyping assessment after 12 weeks of daratumumab treatment. The absolute counts of the CD38 maker were 0 in B cells.
case_images: fmed-11-1360979-g002.jpg
case_images: PMC11303131_01_fmed-11-1360979-g002.jpg
case_images: fig2
case_images: Notably, the absolute counts of transitional B cells (CD19+, CD24+, and CD38+) and plasmablasts (CD19+ and CD38+) were undetectable in both the second and third evaluations (Figure 2).
case_images: Trends in patient urine protein and serum creatinine changes. PRED, prednisone; VAL, valsartan.
case_images: fmed-11-1360979-g003.jpg
case_images: PMC11303131_01_fmed-11-1360979-g003.jpg
case_images: fig3
case_images: Moreover, the edema of the patients completely subsided after 1 month of treatment with daratumumab plus half-dose steroids and 80 mg of valsartan, with 0.55 g/d proteinuria and 1.26 mg/dL serum creatinine (Figure 3). After 3 months of treatment, further improvements were observed, as proteinuria was reduced to 0.18 g/d, serum creatinine decreased to 0.86 mg/dL (Figure 3), and the absolute count of CD38 marker in B cells was reduced to zero.