Antitubular Basement Membrane Antibody Disease Associated with Nivolumab Infusion and Concomitant Acute Pyelonephritis Leading to Acute Kidney Injury : a Case Report and Literature Review

Figure 1

Histopathologic findings on kidney biopsy. (a) Moderate interstitial fibrosis and tubular atrophy throughout cortex (masson trichrome stain, 20x magnification, scale bar = 500 μm). (b) Unremarkable glomerulus (periodic acid Schiff stain, 400x magnification, scale bar = 20 μm). (c) Interlobular artery with severe intimal fibrosis (SMMT stain, 400x magnification, scale bar = 20 μm). (d) Neutrophil-rich infiltrate within tubulointerstitium (hematoxylin and eosin stain, 200x magnification, scale bar = 50 μm). (e) Neutrophilic tubulitis (jones methenamine silver stain, 600x magnification, scale bar = 20 μm). (f) Mixed interstitial inflammation with lymphocytes, plasma cells, eosinophils, histiocytes, and focal neutrophils (hematoxylin and eosin stain, 600x magnification, scale bar = 20 μm). (g) Lymphocytic tubulitis (jones methenamine silver stain, 400x magnification, scale bar = 20 μm). (h) Linear IgG staining along proximal tubular basement membranes (fluorescein-conjugated antihuman IgG stain, 100x magnification, scale bar = 100 μm), with lack of staining along glomerular basement membranes. (i) Linear IgG staining along proximal tubular basement membranes (fluorescein-conjugated antihuman IgG stain, 100x magnification, scale bar = 100 μm).