PAX8 and WT1 Stains Can Highlight Hyperplastic Podocytes of Collapsing Glomerulopathy (CGN)
Document Type
Conference Proceeding
Publication Date
3-2025
Publication Title
Laboratory Investigation
Abstract
Background: CGN (also called collapsing focal segmental glomerulosclerosis) is clinically characterized by nephrotic syndrome and profound renal failure and morphologically characterized by collapsing glomerular capillary loops, podocyte hyperplasia, and tubular cystic dilation. As some CGN do not show typical features with subtle changes in podocyte hyperplasia microscopically, this study investigated whether two popular markers, PAX8 and WT1, can be used to confirm podocyte hyperplasia in CGN. Design: Immunohistochemical (IHC) stains for PAX8 and WT1 were performed in 18 renal biopsies with CGN as the study group and ten negative controls (normal and other glomerular diseases). Serum creatinine levels (sCr, mg/dl) and urine protein/ creatinine ratio (UPCR, mg/mg) were recorded for all cases. Glomerular expressions were compared between the two groups. Results: In negative controls, PAX8 nuclear staining was only seen in the parietal epithelium but not in podocytes (Figure 1A1B). At the same time, WT1 showed diffuse nuclear and cytoplasmic expression in podocytes but was either negative or weakly expressed in the nuclei of the parietal epithelium (figure 1C). By contrast, the hyperplastic podocytes revealed strong nuclear staining of PAX8 as parietal epithelium in the collapsed glomeruli of CGN (figure 1D-1E with orange arrow and Table 1). Meanwhile, WT1 expression was largely lost in hyperplastic podocytes of CGN, making a collapsed loop area with a “naked” look (figure 1F, organ arrow). Conclusions: Our data indicate that both PAX8 and WT1 stains can be easily used to confirm the podocyte hyperplasia of CGN, particularly in biopsies with subtle changes. Furthermore, our data support the view that the hyperplastic podocytes of CGN are derived from the parietal epithelial cells with a progenitor capacity.
Volume
105
Issue
3 Suppl
First Page
10
Last Page
11
Recommended Citation
Metcalf B, Kanaan H, Li W, Zhang P. PAX8 and WT1 stains can highlight hyperplastic podocytes of collapsing glomerulopathy (CGN). Lab Invest. 2025 Mar;105(3 Suppl):10-11. doi: 10.1016/j.labinv.2024.103726
DOI
10.1016/j.labinv.2024.103726
Comments
114th Annual Meeting of the United States and Canadian Academy of Pathology (USCAP), March 22-27, 2025, Boston, MA