Diagnostic Categories for Renal Allograft Biopsies ('97)
Kidney Transplantation

2005 Update of Banff 97 Diagnostic Categories for Renal Allograft Biopsies
1. Normal
2. Antibody mediated rejection-due to documented anti-donor antibody ('suspicious for' if antibody not demonstrated); may coincide with categories 3-6
a. Acute antibody-mediated rejection
Type (Grade)
Histopathological Findings
I
ATN-like; C4d positive, minimal inflammation
II
Capillary margination and/or thromboses, C4d positive
III
Arterial v3 changes, C4d positive
b. Chronic active antibody-mediated rejection
Grade
Histopathologic Findings
---
Glomerular double contours and/or peritubular capillary basement membrane multilayering and/or interstitial fibrosis/tubular atrophy and/or fibrous intimal thickening in arteries; C4d positive
3. Borderline Changes:"Suspicious" for acute T-cell-mediated rejection
Grade Histopathological Findings
"Suspicious"
This category is used when no intimal arteritis is present, but there are foci of tubulitis (t1, t2 or t3 with i0 or i1) although the i2 t2 threshold for rejection diagnosis is not met (may coincide with categories 2, 5 and 6)
4. T-cell mediated rejection (may coincide with categories 2, 5 and 6)
a. Acute T-cell-mediated rejection
Type (Grade) Histopathological Findings
IA Cases with significant interstitial infiltration (>25% of parenchyma affected, i2 or i3) and foci of moderate tubulitis (t2)
IB Cases with significant interstitial infiltration (> 25% of parenchyma affected, i2 or i3) and foci of severe tubulitis (t3)
IIA Cases with mild to moderate intimal arteritis (v1)
IIB Cases with severe intimal arteritis comprising > 25% of the lumenal area (v2)
III Cases with "transmural" arteritis and/or fibrinoid change and necrosis of medial smooth muscle cells with accompanying lymphocytic inflammation (v3)
b. Chronic active T-cell-mediated rejection
Type
Histopathological Findings
---
"Chronic allograft arteriopathy" (arterial intimal fibrosis with mononuclear cell infiltration in fibrosis, formation of neo-intima)
5. Interstitial fibrosis and tubular atrophy, no evidence of any specific etiology
Grade Histopathological Findings
  Note: Grades I, II and III may include nonspecific vascular and glomerular sclerosis, but severity is graded by tubulointerstitial features
Grade I (mild)
Mild interstitial fibrosis and tubular atrophy (<25% of cortical area)
Grade II (moderate)
Moderate interstitial fibrosis and tubular atrophy (26-50% of cortical area)
Grade III (severe)
Severe interstitial fibrosis and tubular atrophy/loss (>50% of cortical area)
6. Other: Changes not considered to be due to rejection
Diagnosis
Histopathological (and other) features
Chronic hypertension Arterial/fibrointimal thickening with reduplication of elastica, usually with small artery and arteriolar hyaline changes
Calcineurin toxicity Arteriolar hyalinosis with peripheral hyaline nodules and/or progressive increase in the absence of hypertension or diabetes. Tubular cell injury with isometric vacuolization
Chronic obstruction Marked tubular dilatation. Large Tamm-Horsfall protein casts with extravasation into interstitium, and/or lymphatics
Bacterial pyelonephritis Intratubular and peritubular neutrophils, lymphoid follicle formation
Viral infection Viral inclusions on histology and immunohistology and/or electron microscopy
Reference
  1. Solez K, et al. Banff '05 meeting report: Differential diagnosis of chronic allograft injury and elimination of chronic allograft nephropathy ('CAN'). Am J Transplant 7:518-526, 2007.


Please mail comments, corrections or suggestions to the TPIS administration at the UPMC.

Home  |  Contact  |  Statement of Purpose


Please mail comments, corrections or suggestions to the TPIS administration at the UPMC.

Last Modified: Thu Jun 18 10:14:08 EDT 2009