Figure 1

Renal histologic findings in the patient. Marked tubulointerstitial mononuclear cell infiltration was observed (a; Masson trichrome stain, ×100). Crescent formation was noted in some glomeruli (b; periodic acid-Schiff stain, ×200). Fluorescent antibody staining demonstrated granular deposition of IgG in the tubular basement membrane (c; ×200). Electron-dense deposits were present in the tubular basement membrane (d; original magnification, ×6000). Immune cells infiltrating in tubulointerstitial tissue were mainly CD3-positive T-cells (e), as opposed to IgG4-bearing cells (f; ×200).