Table 1.

Mechanisms of recognition of xenografts and pathways of injury.

Factor	Specificity	Pathway	Outcome	References
Antibodies	Galα1-3Gal	Direct activation of EC, Complement, Fc receptor	Vascular rejection	[18]
Antibodies	MHC and other proteins	Direct activation of EC, Complement, Fc receptor	Vascular rejection	[29]
Complement	Bound antibodies	Cytotoxicity, EC activation	Vascular rejection	[49]
T cells	MHC	Cytotoxicity, cytokines	Cellular rejection	[50]
T cell	All proteins	Cytotoxicity, cytokines	Cellular rejection	[51]
NK cells	Non-MHC, Fc, Galα1–3Gal	Cytotoxicity, EC activation, cytokines	Vascular damage	[52]
Neutrophils	Unknown	Cytotoxicity	EC activation, vascular damage	[53]
Macrophages	Unknown	Cytotoxicity, coagulation	Vascular damage, coagulation	[54]
Platelets	VWF	Thrombosis, EC activation	Vascular damage, coagulation	[55]
Coagulation	Lack of control	TF	Coagulation, thrombosis	[37]