Figure 4. Results of immunostaining with antibodies against α1, α3, and α5 chains of type IV collagen in the AS/VUR patient.

(A) ColIVα1 expression is strong and consistent in the basement membranes (BM) of the glomeruli and the tubules; typically it is absent in adult glomeruli. Images show absent α3IV (B) and weak α5IV (C) staining in the glomerular BMs. (D&E) Electron micrograph from this patient shows segmental glomerular basement membrane (GBM) lamellation and outpouching (D arrow) and irregular thickening (E arrow) of the GBM characteristic of AS. COL4α3 immunostaining in control shows the normal tubular and capillary loop distribution for comparison (F).