Organ Transplant Rejection & Immunosuppression

A transplant recipient spikes a fever on post-op day 5 — is this infection or the body attacking its new organ? The timeline tells you everything.

Transplant rejection occurs when the recipient's immune system recognizes donor tissue as foreign and mounts an attack. Three types are classified by timeline and mechanism. Hyperacute rejection happens within minutes to hours of transplant due to preformed antibodies — the organ turns cyanotic and must be removed immediately. This is rare today because of crossmatching. Acute rejection is the most common and most testable type, occurring days to months post-transplant (typically within the first 3-6 months). It presents with organ-specific dysfunction: rising creatinine in kidney transplants, elevated liver enzymes in liver transplants, decreased ejection fraction in heart transplants. Fever, tenderness over the graft site, and malaise are classic signs. Acute rejection is most often T-cell mediated (acute cellular rejection) and often reversible with increased immunosuppression (high-dose corticosteroids, antithymocyte globulin). Chronic rejection develops over months to years, involves gradual fibrosis and vascular changes, and is irreversible — the organ slowly fails despite immunosuppression. Nursing priorities center on monitoring for rejection signs, ensuring immunosuppressant adherence (tacrolimus trough levels vary by organ and time post-transplant — verify institution-specific target ranges), and teaching the client that lifelong immunosuppression is non-negotiable. Any fever, graft tenderness, or sudden change in organ function labs warrants immediate provider notification.

Key Distinctions

Don't confuse acute rejection (reversible with treatment escalation) with chronic rejection (irreversible, gradual organ failure). Students mix up hyperacute rejection (antibody-mediated, minutes) with acute rejection (T-cell mediated, days to months). Rejection symptoms mimic infection — both cause fever — but rejection adds organ-specific lab changes and graft tenderness, while infection typically shows a localizable source and elevated WBC with left shift.

Clinical Pearl

Think timeline: minutes = hyperacute (remove it), months = acute (treat it), years = chronic (lose it). Acute is the one you can actually fix.