Table 1.

Framework of ABMR clinical phenotypes.

Timing	Donor specific antibody		Histology	Clinical presentation
Hyperactive rejection (hours post-transplant)	Preexisting		Diffuse inflammation, necrosis, and thrombotic microangiopathy	Abrupt graft loss
Early active (<30 days post-transplant)	Preexisting (or patient is Non immunologically naïve with history of sensitizing events including pregnancy, transplant, or blood transfusion)	Can have similar histologic features depending on time of detection	Banff active ABMR C4d positivity and thrombotic microangiopathy usually present. Banff cg = 0	Abrupt allograft dysfunction correlating with increased DSA quantity usually 7–14 days post-transplant
Late (>30 days post-transplant)	Preexisting		Banff active or chronic active ABMR (continuum) +/− C4d positivity	+/− allograft dysfunction and proteinuria Can occur in patients with or without Early active (<30 days post-transplant active ABMR)
	De novo (MOST COMMON)		Banff active or chronic active ABMR (continuum) +/− C4d positivity Concomitant TCMR often present with de novo DSA	+/− allograft dysfunction and proteinuria