Infectious Disease and Post-Transplant Complications
Core concepts
Understand the timeline of post-transplant infection: early surgical and nosocomial infections, then opportunistic infections (cytomegalovirus, Pneumocystis, Epstein-Barr virus, BK virus), then community-acquired infections. Know prophylaxis: trimethoprim-sulfamethoxazole for Pneumocystis and toxoplasmosis, valganciclovir for cytomegalovirus based on donor and recipient serostatus, and antifungal and antiviral strategies. Learn donor-derived infection and screening, cytomegalovirus disease versus infection, BK nephropathy, post-transplant lymphoproliferative disorder, and Epstein-Barr virus monitoring. Also know non-infectious complications: drug toxicity, malignancy, cardiovascular disease, and recurrence of primary disease.
Traps
Questions test donor and recipient serostatus: a cytomegalovirus-seronegative recipient of a seropositive donor is highest risk and needs prophylaxis. Another trap is confusing BK viremia with nephropathy, or treating BK by increasing immunosuppression. Do not miss that Pneumocystis prophylaxis can be stopped in some patients but not all. Watch for drug interactions: valganciclovir and mycophenolate, and azoles raising tacrolimus levels.
Worked example
A kidney recipient six months out with rising creatinine and BK viremia. Rule of thumb: reduce immunosuppression first and monitor viral load; biopsy distinguishes BK nephropathy from rejection, and pulse steroids would worsen BK.
Study strategy
Draw a timeline of infection risk by month and match each prophylaxis to its target organism.