Singh, Nina

CMV-specific T cells, NK cells, and neutralizing antibodies (nAbs) were assessed in a randomized trial of CMV prevention with preemptive antiviral therapy (PET) versus prophylactic antiviral therapy (PRO) in donor-seropositive/recipient-seronegative (D + R – ) liver transplant recipients (LTxR) at 100 days (end of intervention) and at 6 and 12 months after transplant. The PET group had significantly increased numbers of circulating polyfunctional T cells, NK cells, and nAbs compared with the PRO group at day 100, and several CMV immune parameters remained significantly higher by 12 months after transplant. Among PET recipients, preceding CMV viremia (vs. no preceding viremia) was associated with significantly higher levels of most CMV immune parameters at day 100. Higher numbers of CMV-specific polyfunctional T cells and NKG2C + NK cells at day 100 were associated with a decreased incidence of CMV disease in multivariable Cox regression. The strongest associations with protection against CMV disease were with increased numbers of CMV-specific polyfunctional CD4 + T cells, CD3 neg CD56 dim CD57 neg NKG2C pos cells, and CD3 neg CD56 dim CD57 pos NKG2C pos NK cells. Our results suggest that PET is superior to PRO for CMV disease prevention by allowing low-level CMV replication and associated antigen exposure that is promptly controlled by antiviral therapy and facilitates enhanced CMV protective immunity in D + R – LTxR.

Abstract Background Detailed cytomegalovirus (CMV) kinetics in donor CMV-seropositive, recipient CMV-seronegative (D+/R–) transplant recipients receiving preemptive therapy (PET) have not been fully defined. Methods The study population consisted of the PET arm of a randomized CMV prevention trial in D+/R– liver transplant recipients. CMV DNA polymerase chain reaction (PCR) assays were performed weekly for 100 days using a sensitive assay. Viral load and clinical parameters were compared for patients with or without high-level increase (defined as higher than the group median log10 increase in viral load from baseline after PET initiation). Results Among 79 patients, 93.6% (74/79) developed an increase from baseline viral loads of median 120 IU/mL to 3350 IU/mL; 25.7% (19/74) of the patients had peak levels >10 000 IU/mL. None of the patients with rise in viral load underwent testing for CMV resistance, and viremia resolved with PET with valganciclovir. Patients with high-level increase in viral load had a significantly lower rate of recurrent viremia than those without such increase (16/40 [40%] vs 28/39 [71.8%], respectively; P = .004). Conclusions A majority of D+/R– recipients had a marked increase in viral load after initiation of PET before resolution of viremia. This phenomenon is associated with lower rates of subsequent recurrent viremia and does not necessarily imply antiviral resistance.

Background. Risk factors, virological parameters, and outcomes associated with HHV-6 viremia in high-risk donor CMV-seropositive and recipient CMV-seronegative (D+R–) liver transplant recipients in the current era are incompletely defined. Methods. The study population consisted of patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus valganciclovir prophylaxis for CMV prevention in D+R– liver transplant recipients. Weekly blood samples through 100 d in the PET group were tested for HHV-6 viremia using a real-time quantitative polymerase chain reaction. Assessments included virological characteristics and relationship with CMV, risk factors, and impact of HHV-6 viremia with outcomes through 12 mo posttransplant. Results. HHV-6 viremia at any level developed in 42% (40 of 96). Older patient age (P = 0.03), longer hospitalization (P = 0.015), and ICU stay at transplantation (P = 0.029) were significantly associated with high-grade viremia. Concurrent HHV-6 and CMV viremia was associated with earlier onset of HHV-6 viremia (P = 0.004), higher HHV-6 area under the curve (P = 0.043), and higher peak HHV-6 viral load (P = 0.006) versus HHV-6 viremia alone. High-grade viremia was independently associated with biopsy-proven rejection within 12 mo (P = 0.045) posttransplant. Conclusions. Among D+R– liver transplant recipients receiving valganciclovir as PET, high-grade HHV-6 viremia was associated with increased age and critical illness in ICU at time of transplant and was independently associated with allograft rejection.

Abstract Background The risk factors for development of viremia in high-risk donor cytomegalovirus (CMV)-seropositive and recipient CMV-seronegative (D+R−) transplant recipients are incompletely defined. Methods The study population comprised patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus prophylaxis using valganciclovir in D+R− liver transplant recipients. Weekly surveillance monitoring for viremia for 100 days was performed using a sensitive CMV-DNA polymerase chain reaction assays. Risk factors for viremia and time to onset (≤4 vs >4 weeks) of viremia were examined using logistic regression models. Results Viremia developed in 84% (79/94) of recipients and older donor age was the only independent factor associated with viremia (odds ratio, 2.20 for each quartile increase in donor age; 95% confidence interval [CI], 1.07–4.52; P = .031). Recipients who developed early-onset viremia (within 4 weeks) also had significantly older donors than those with later-onset viremia (difference in age 10.1 years; 95% CI, 2–19; P = .03). Conclusions Older donor age was an independent predictor of viremia and earlier-onset of viremia in D+R− liver transplant recipients. Future studies should assess the mechanistic links underlying this novel association. Clinical Trial Registration NCT01552369.

AbstractBackgroundThe relative costs of preemptive therapy (PET) or prophylaxis for the prevention of cytomegalovirus (CMV) disease in high-risk donor CMV-seropositive/recipient-seronegative (D+/R−) liver transplant recipients have not been assessed in the context of a randomized trial.MethodsA decision tree model was constructed based on the probability of outcomes in a randomized controlled trial that compared valganciclovir as PET or prophylaxis for 100 days in 205 D+/R− liver transplant recipients. Itemized costs for each site were obtained from a federal cost transparency database. Total costs included costs of implementation of the strategy and CMV disease treatment-related costs. Net cost per patient was estimated from the decision tree for each strategy.ResultsPET was associated with a 10% lower absolute rate of CMV disease (9% vs 19%). The cost of treating a case of CMV disease in our patients was $88 190. Considering cost of implementation of strategy and treatment-related cost for CMV disease, the net cost-savings per patient associated with PET was $8707 compared to prophylaxis. PET remained cost-effective across a range of assumptions (varying costs of monitoring and treatment, and rates of disease).ConclusionsPET is the dominant CMV prevention strategy in that it was associated with lower rates of CMV disease and lower overall costs compared to prophylaxis in D+/R− liver transplant recipients. Costs were driven primarily by more hospitalizations and higher CMV disease–associated costs due to delayed onset postprophylaxis disease in the prophylaxis group.

Abstract Background Current guidelines preferentially recommend valganciclovir (VGCV) prophylaxis over PET in most D+R− organ transplant populations, but adequately powered direct comparative clinical trials are lacking. Methods D+R− LTR were randomly assigned (1:1, stratified by site and T-cell depleting induction) to receive either PET (weekly plasma CMV DNAemia at central laboratory for 100 days, with VGCV 900 mg bid for DNAemia at any level, until two consecutive negative weekly tests) or prophy (VGCV 900 mg qd for 100 days). The primary outcome was CMV disease by 12 months as adjudicated by an independent, blinded, endpoint committee in ITT population. Secondary outcomes were opportunistic infections (OIs) (invasive fungal and bacterial), neutropenia (ANC < 1000/µL), acute rejection, graft loss, and mortality assessed at12 months. Results From October 2012 to June 2017, 205 patients were randomized at six centers; 100 to PET, 105 to prophy. The incidence of CMV disease was 9% (9/100) in PET and 19% (20/105) in prophy (P = 0.039) with majority of difference due to post-prophylaxis disease: 6% in PET vs. 17% in prophy (P = 0.027). CMV disease included syndrome in 55% (16/29) and end-organ in 45% (13/29), with similar proportions in two groups. Secondary outcomes were not different for PET and prophy groups: OIs (19% vs. 21%), neutropenia (34% vs.. 28%), acute rejection (27% vs. 27%), graft loss (2% vs. 2%), and mortality (10% vs. 6%), respectively, P > 0.05 for all comparisons. Mortality at last follow-up (median 3.2 years) was not different for PET vs. prophy (14% vs. 18%, P = 0.43). Conclusions PET significantly reduced the incidence of CMV disease compared with prophy in D+R- LTR, and was associated with similar other clinical outcomes. Current guidelines should be revised to recommend PET over prophylaxis in this setting, and similar trials conducted in other D+R− transplant populations. (Funded by NIAID; ClinicalTrials.gov# NCT01552369.) Disclosures D. Winston, Merck: Investigator, Research support. Chimerix: Investigator, Research support. Shire: Investigator, Research support. Gilead: Investigator, Research support. Oxford Immunotech: Investigator, Research support. G. M. Lyon III, Shire: Investigator, institutional research support. Hookipa: Investigator, institutional research support. Merck: Investigator, institutional research support. F. P. Silveira, Shire: contracted clinical research, site investigator. A. P. Limaye, Merk: Consultant and Investigator, Consulting fee and Research grant. Astellas Pharma Inc.: Consultant and Investigator, Consulting fee. Helocyte Inc.: Consultant, Consulting fee.