Additional evidence to support routine cytomegalovirus prophylaxis for all D+/R+ renal graft recipients

Evaluation of a Cytomegalovirus Prophylaxis Protocol in Cytomegalovirus-IgG Positive Renal Transplant Recipients (R+)

BACKGROUND

The aim of the study was to evaluate the efficacy of a unique cytomegalovirus- (CMV) prophylaxis protocol in terms of CMV infection and disease progression in CMV IgG positive kidney transplant recipients.

METHODS

Achievement of negative CMV load, using concurrent prophylactic intravenous ganciclovir therapy during induction immunosuppression, combined with a 6-month prophylactic course of acyclovir, would yield a reduced incidence of early CMV infection and disease. CMV DNA was tested for at discharge, at the third, and sixth post-op months, and at the occurrence of any event that could be associated with CMV infection. CMV DNA positive patients received ganciclovir treatment until the viral load became negative. CMV replication was monitored using a quantitative PCR method capable of detecting as few as 42.5 copies/mL. All patients were given a maintenance dose of acyclovir.

RESULT

The file data of 267 patients who had undergone kidney transplantation between 2007 to 2016 were examined. Thirty-four patients were excluded from the study for various reasons, unrelated to the protocol. Of the remaining 233 patients, 42 (18%) had CMV DNA infection. Three patients had CMV disease (1.3%), 1of whom died of pneumonia. Diabetes mellitus (DM) was a risk factor for CMV DNA positivity (P < .004).

CONCLUSION

The incidence of CMV infection and disease is low in renal transplant recipients whose CMV viral load is eliminated after concurrent ganciclovir administration with induction immunosuppression.

NK cell and Th17 responses are differentially induced in murine cytomegalovirus infected renal allografts and vary according to recipient virus dose and strain

Human cytomegalovirus (HCMV) donor positive (D+) serostatus with acute rejection is associated with renal allograft loss, but the impact of recipient positive (R+) serostatus is unclear. In an allogeneic renal transplant model, antiviral natural killer (NK) and CD8+ T cell memory responses in murine CMV (MCMV) D+/R+ transplants were compared to D-/R- and D+/R- transplants, with recipient infection varied by MCMV dose and strain. D+/R- transplants had high primary antiviral cytolytic (interferon-γ+) and cytotoxic (granzyme B+) NK responses, whereas NK memory responses were lower in D+/R+ recipients receiving a high primary MCMV dose. Despite MCMV immunity, D+/R+ recipients receiving a low MCMV dose showed primary-like high cytolytic and cytotoxic NK responses. D+/R+ transplants infected with different D/R strains had low cytolytic NK responses but high cytotoxic NK responses. NK memory also induced a novel TNF-α+ NK response among high-dose virus recipients. MCMV+ transplants had greater Th17 responses than MCMV-uninfected transplants and Th17 inhibition ameliorated graft injury. All MCMV+ recipients had similar CD8+ T cell responses. In sum, NK and Th17 responses, but not CD8+ T cells, varied according to conditions of primary recipient infection. This variability could contribute to variable graft outcomes in HCMV D+/R+ renal transplantation.