Fig. 4.

Changes in light microscopy findings of the renal interstitium after corticosteroid therapy. Azan staining showed that interstitial fibrosis was not evident 1 month after corticosteroid therapy in patient 6 (a), whereas localized severe fibrosis was observed 14 months after therapy in patient 1 (b). There were mixed lesions where cell infiltration was dense (c) or fibrosis was predominant (d) or neither of them was noted (e) 4 months after therapy in patient 5. Interstitium in the posttreatment specimen of patient 6 seemed to show recovery of some renal tubules 1 month after corticosteroid therapy (f) [a–e Azan staining ×100, f periodic acid-Schiff (PAS) staining ×100]