Copyright ©The Author(s) 2023.
World J Transplant. Mar 18, 2023; 13(3): 86-95
Published online Mar 18, 2023. doi: 10.5500/wjt.v13.i3.86
Table 1 Classification and diagnostic criteria used in pig-to-primate solid organ transplantation pathology
Hyperacute rejection
Acute humoral xenograft rejection
Acute cellular xenograft rejection
Time period
Immediately after reperfusion of the graft (typically within 24 h)Later after reperfusion (after 24 h)After 3 d
Immediate graft function
No (no urine since reperfusion)Yes, urine formation initiallyYes, urine formation initially
Histopathologic features
Massive hemorrhage; Immunoglobulin and fibrin deposition; Complement (C5b-9) deposition; Presence of neutrophils; Thrombosis, ±Hemorrhage present; Immunoglobulin and fibrin deposition; Complement (C5b-9) deposition; Presence of neutrophils; Lymphocytes may be present; Necrosis and transmural infiltration by neutrophils in blood vessels can be present; Apoptosis may be present; Thrombosis presentNo hemorrhage; Immunoglobulin and fibrin deposition, rare; Complement, ±; Presence of mononuclear (lymphoid) cells associated with tissue destruction (e.g., tubulitis); No thrombosis
Table 2 Types of chronic xenograft vasculopathy
Type of vasculopathy
Histopathological features
Chronic humoral rejection-associated vasculopathyArterial intimal thickening; Presence of TUNEL+ cells; Deposits of fibrin, immunoglobulins (IgG and IgM), and complement components (C3, C4d, and C5b-9)
Chronic cellular rejection-associated vasculopathyMononuclear cell infiltration in the neointima; Active endothelialitis; TUNEL+ cells
Combined chronic humoral and cellular rejection-associated vasculopathyFibrinoid material deposition and cellular infiltration in the arterial neointima with immunoglobulin and complement deposition and infiltration of T cells, macrophages, and polymorphonuclear leukocytes
Fully developed vasculopathyNarrowing of arteries with a fibrotic neointima, but without fibrinoid material, or cellular infiltration