Antiviral Prophylaxis and Monitoring in Solid Organ Transplantation

Cytomegalovirus (CMV) Prophylaxis

Start universal CMV prophylaxis immediately at transplantation for all at‑risk recipients (any donor positive or recipient positive, except D‑/R‑). Use oral valganciclovir 900 mg daily (dose‑adjusted for renal function) or oral ganciclovir; give a minimum of 3 months for standard‑risk kidney transplants and extend to 6–12 months for high‑risk kidney (D⁺/R⁻) and lung transplants. KDIGO Grade 1B (strong evidence of reduced CMV disease, all‑cause mortality, and CMV‑related death). 1
After T‑cell‑depleting antibody therapy for acute rejection, initiate CMV prophylaxis immediately and continue for 6 weeks after the last dose, regardless of baseline serostatus. Valganciclovir 900 mg daily (renal‑adjusted) is recommended. KDIGO Grade 1C (evidence that even CMV‑R⁺ patients benefit). [1][2]

Perform weekly quantitative plasma nucleic‑acid testing (NAT) or pp65 antigenemia during periods of active CMV disease or high‑risk intervals. Plasma viral load is the preferred method over antigenemia. [1][6]

Screen plasma BK‑virus DNA monthly for the first 3–6 months post‑transplant, then every 3 months through the end of the first year. Add an extra screening episode after any treatment for acute rejection because intensified immunosuppression raises reactivation risk. [1][6]7

For recipients with a prior HSV history, begin prophylaxis at transplantation with acyclovir, valacyclovir, or famciclovir and continue for at least 30 days post‑transplant. In autologous hematopoietic stem‑cell transplant (HSCT) recipients, maintain therapy throughout periods of neutropenia. [3][4]

Allogeneic HSCT recipients should start acyclovir, valacyclovir, or famciclovir at transplantation and continue for a minimum of 1 year thereafter. [3][4]

HBV‑positive transplant recipients require immediate initiation of nucleos(t)ide analogue therapy (entecavir or tenofovir preferred) at transplantation and indefinite continuation to prevent viral reactivation. 5
HBV‑negative recipients receiving organs from HBV‑positive donors should also start nucleos(t)ide analogue prophylaxis at transplantation and maintain it long‑term. 5

Do not start HCV antiviral therapy immediately after transplantation. Defer treatment until ≥ 6 months post‑transplant and confirm chronic hepatitis C histologically before initiating therapy. Initiate treatment earlier only if the recipient has advanced fibrosis or portal hypertension, which predict rapid disease progression. 5

Do not omit CMV prophylaxis based solely on serostatus; approximately one‑quarter of all transplant recipients develop CMV infection regardless of donor/recipient serology. 2
Do not delay the start of antiviral prophylaxis; it must begin at transplantation or at the onset of T‑cell‑depleting therapy to be effective. [1][2]
Do not initiate HCV treatment earlier than the recommended 6‑month post‑transplant window, as early therapy is associated with higher rates of drug intolerance and potential allograft rejection. 5
Do not rely on urine BK testing alone; plasma viral load provides a more specific assessment of nephropathy risk and should guide management decisions. [6][7]