Table 1.

Banff 2007 update of Banff 1997 diagnostic categories for renal allograft biopsies

Diagnostic category	Description	Criteria
1. Normal
2. Antibody-mediated changes	C4d deposition without morphologic evidence of active rejection	C4d+; circulating DSA present; no signs of acute or chronic TCMR or ABMR
	Acute antibody-mediated rejection	C4d+; circulating DSA present; morphologic evidence of acute tissue injury such as acute tubular necrosis, capillaritis, and/or glomerulitis and/or thrombosis; severe arteritis (v3)
	Chronic active antibody-mediated rejection	C4d+; circulating DSA present; morphologic evidence of chronic tissue injury such as glomerular double contours and/or peritubular capillary basement membrane multilayering; IF/TA; fibrous intimal thickening in arteries
3. Borderline change	“Suspicious” for acute T-cell-mediated rejection	No intimal arteritis (v0), but there are interstitial infiltrates and tubulitis insufficient to meet criteria for T-cell-mediated rejection (i0-i1, t1-t3 or i2-i3, t1)
4. T-cell-mediated rejection (TCMR)	Acute T-cell-mediated rejection	Type I: i2-3, t2-3 Type II: v1-v2 Type III: v3
	Chronic active T-cell-mediated rejection	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	Severity graded I–III by the extent of tubulointerstitial fibrosis and atrophy
6. Other	Changes not considered to be due to rejection	For example, acute pyelonephritis, BK polyoma virus interstitial nephritis

Data adapted from Solez et al. (2008).