case_images: PMC11744802_01
case_images: Renal pathological results for the patient. a-c Light microscopic observations reveal moderate to severe hyperplasia of glomerular mesangial cells (green circles) accompanied by nodular alterations, lobulated glomerular capillary loops, narrowing and occlusion of the capillary lumen, thickening of the basement membrane, segmental mesangial insertion, and double-track formation (indicated by the green arrows). Additionally, there is erythrophilic protein deposition in the mesangial region and subepithelial, along with the formation of small-cell fibrous crescentic bodies in certain areas (indicated by the yellow arrows), and mild fibrosis surrounding a few glomerular balloons (a, 150x; b, 300x; c, 300x). d Immunofluorescence of IgA, with red arrows indicating clumped deposition of IgA in the mesangial region and capillary loops. e Immunofluorescence of C3 reveals a blue arrow indicating C3 in the mesangial membrane region, alongside petal-like deposition of C3 along capillary loops and linear deposition in Bowman's capsule and a portion of the renal tubule basement membrane. f-h Electron microscopy reveals segmental thickening of the glomerular basement membrane accompanied with diffuse fusion of podocyte foot processes, as well as high-density electron-dense deposits observed in the mesangial region, the dense layer of the basement membrane, and the wall of Bowman's capsule
case_images: 12887_2025_5415_Fig1_HTML.jpg
case_images: PMC11744802_01_12887_2025_5415_Fig1_HTML.jpg
case_images: Fig1
case_images: Additionally, there is deposition of erythrophilic protein in the glomerular mesangial region and subepithelial, along with the formation of partially visible small-cell fibrous crescentic bodies (Fig. 1a-c). Immunofluorescence exhibited strong positivity for both IgA and C3, characterized by petaloid deposition of C3 along glomerular capillary loops and the glomerular mesangial region, linear deposition in Bowman's capsule and portions of renal tubular basement membranes (Fig. 1d), clumped deposition of IgA along the glomerular mesangial region and capillary loops (Fig. 1e), weak positivity for IgM, and negativity for IgG, C1q, Fib, ALB, IgG1, IgG2, IgG3, IgG4, PLA2R, and THSD7A. Ultrastructural analysis revealed segmental thickening of the glomerular basement membrane, extensive fusion of podocyte foot processes, and a high density of electron-dense deposits observed in the mesangial area, dense layer of the basement membrane, and the wall of Bowman's capsule (Fig. 1f-h).