Figure 1. Renal biopsy pathology.

Light microscopy reveals areas of patchy interstitial inflammation (A: arrows, hematoxylin and eosin stain, magnification 100X). The inflammatory infiltrate is primarily localized within areas of tubulointerstitial scarring (B: hematoxylin and eosin, magnification 400X). The interstitial inflammatory infiltrate is mixed, with a combination of lymphocytes, plasma cells, and monocytes. Notably absent are neutrophils and eosinophils (C: Periodic acid Schiff stain, magnification 400X).