Table 1.

Scoring system for the assessment of diabetic nephropathy

Parameter	Grade 1	Grade 2	Grade 3
Glomerulosclerosis	Mildly increased glomerular matrix and sclerosis (up to 30%)	Moderate matrix expansion and sclerosis (<50%)	Extensive matrix expansion, Kimmelstiel–Wilson lesions, global obliteration
Tubulointerstitial fibrosis	Mildly increased tubulointerstitial matrix	Increased matrix, initial tubular atrophy widening of the tubulointerstitium	Extensive matrix expansion and tubular atrophy
Inflammation	No relevant inflammatory reaction	Inflammation in up to 50% of the section	Severe inflammation in >50% of the tissue section