Quantitative Kidney Histopathology Analysis

Kidney histopathology was conducted as previously described (22 (link)). Briefly, formalin-fixed, paraffin-embedded sections of 3 µm thickness were stained with hematoxylin and eosin or Periodic Acid-Schiff (PAS) for histopathological analysis. PAS-stained slides were imaged by Aperio Scanscope AT Turbo (Leica Biosystems). Mean glomerular cross-sectional area was quantified by polygon tracing using ImageJ software (NIH, 1.52d). Mean disease score criteria were assessed blinded as follows; 0 – Normal glomerular cellularity and morphology; 1 – Mild cellular expansion and/or early-stage disrupted glomerular morphology which includes lobularity and/or Bowman’s space enlargement; 2 – Advanced cellular expansion with distinct disruption to glomerular morphology, pyknosis and/or karyorrhexis; 3 – Severe cellular expansion/consolidation with advanced lobularity or fragmentation and/or enlargement of the Bowman’s space with cellular infiltration (with or without crescent formation) and/or peri-glomerular cellular expansion and/or evidence of segmental necrosis; 4 – End-stage glomerular destruction, progressive or complete loss of cellularity and/or distinct glomerular morphology. At least 30 glomeruli were assessed for each kidney.