Table 1.
Light and electron microscopy parameters and descriptors used in the study
| Descriptors | Definitions |
|---|---|
| KW nodules (No/Yes) | Round mesangial sclerosing lesions with hypocellular center13 |
| RPS DN class (1/2/3/4) | RPS classification of diabetic nephropathy13 |
| Segmental sclerosis (0/1/2/3/4) | Segmental solidification of the glomerular tuft, scored as % quartiles57 |
| Global sclerosis (0/1/2/3/4) | Solidification of 100% of the glomerular tuft, scored as % quartiles57 |
| Glomerular epithelial hypertrophy (0/1/2/3) | Enlarged epithelial nuclei and/or cytoplasm57; unifocal (1), multifocal (2), diffuse (3) |
| Glomerular epithelial hyperplasia (0/1/2/3) | ≥2 layers of epithelial cells overlying the GBM57; unifocal (1), multifocal (2), diffuse (3) |
| Mesangiolysis (No/Yes) | Dissolution of mesangial matrix ± microaneurysms |
| Insudative lesion (No/Yes) | Hyaline eosinophilic material deposition within the tuft or in Bowman’s capsule58 |
| Interstitial fibrosis | Interstitium expanded by collagenous extracellular matrix, scored as % area of sampled cortex |
| Interstitial lymphocyte (0/1/2/3) | Presence of interstitial lymphocytes; unifocal (1), multifocal (2), diffuse (3) |
| Arteriolar hyalinosis (0/1/2/3) | Hyaline eosinophilic material deposition within arteriolar wall; unifocal (1), multifocal (2), diffuse (3) |
| Intimal fibrosis (0/1/2/3) | Expansion of vascular wall intima by collagenous material; <50% thickness of media (1), 50%–100% thickness of media (2), >100% thickness of media (3) |
| Avg GBM thickness (nm) | Mean of EM measurements taken where grid line intersects endothelium and GBM, excluding areas with segmental collapse or solidification32 |
| GBM Lamina densa remodeling (0/1/2/3) | Lamina densa with lamellation, fraying or lucent patches on EM; focal (1), multifocal (2), diffuse (3) |
| GBM duplication (0/1/2/3) | Deposition of an inner layer of basement membrane-like material on EM; focal (1), multifocal (2), diffuse (3) |
| FPW (μm) | Mean distance between adjacent podocyte filtration slits on filtering capillary walls31 |
| Foot process effacement | Loss of podocyte foot processes, excluding areas where 2 GBMs touch, scored as %42 |
| Endothelial fenestration loss (0/1/2/3) | Loss of endothelial pores resulting in solid rim of cytoplasm42 focal (1), multifocal (2), diffuse (3) |
| Mesangial hyaline (0/1/2/3) | Deposition of fine, uniform, electron-dense material lacking sharp edges42; focal (1), multifocal (2), diffuse (3) |
| Mesangial matrix increase (0/1/2/3) | Expansion of mesangial matrix beyond width of 2 mesangial nuclei; mild (1), moderate (2), severe (3) |
Avg GBM, average glomerular basement membrane; FPW, foot process width; KW, Kimmelstiel-Wilson Nodule; RPS DN class, Renal Pathology Society diabetic nephropathy class.