Which primary rejection mechanism can present within days after transplant and is suggested by early thrombosis with no cellular infiltration?

Which primary rejection mechanism can present within days after transplant and is suggested by early thrombosis with no cellular infiltration?

• A. Hyperacute rejection
• B. Acute humoral rejection
• C. Accelerated humoral rejection
• D. Acute cellular rejection

Answer: (C)

When immune injury to a transplanted organ is driven by antibodies rather than T cells, you get damage to the graft’s blood vessels. Antibody‑mediated injury activates complement, causes endothelial damage, and leads to thrombosis in the graft vessels. This pattern often shows little to no lymphocytic cellular infiltration because the injury is vascular and humoral rather than cellular. If thrombosis appears early after transplant and you don’t see cellular infiltration, it points to antibody‑mediated injury that happens rapidly due to preformed or swiftly formed donor‑specific antibodies. When this occurs within days after transplantation, it’s described as accelerated humoral rejection. This distinguishes it from hyperacute rejection (which happens within minutes to hours) and from cellular rejection (which characteristically shows T cell–mediated infiltration).

When immune injury to a transplanted organ is driven by antibodies rather than T cells, you get damage to the graft’s blood vessels. Antibody‑mediated injury activates complement, causes endothelial damage, and leads to thrombosis in the graft vessels. This pattern often shows little to no lymphocytic cellular infiltration because the injury is vascular and humoral rather than cellular.

If thrombosis appears early after transplant and you don’t see cellular infiltration, it points to antibody‑mediated injury that happens rapidly due to preformed or swiftly formed donor‑specific antibodies. When this occurs within days after transplantation, it’s described as accelerated humoral rejection. This distinguishes it from hyperacute rejection (which happens within minutes to hours) and from cellular rejection (which characteristically shows T cell–mediated infiltration).