CMV-seropositive Kidney Transplant Research Articles

QuantiFERON-CMV as a Predictor of CMV Events During Preemptive Therapy in CMV-seropositive Kidney Transplant Recipients.

Prevention of cytomegalovirus (CMV) infection after kidney transplantation is costly and burdensome. Given its promising utility in risk stratification, we evaluated the use of QuantiFERON-CMV (QFCMV) and additional clinical variables in this prospective cohort study to predict the first clinically significant CMV infection (CS-CMV, ranging from asymptomatic viremia requiring treatment to CMV disease) in the first posttransplant year. A cost-effectiveness analysis for guided prevention was done. One hundred adult kidney transplant recipients, CMV IgG + , were given basiliximab induction and maintained on steroid/mycophenolate/tacrolimus with weekly CMV monitoring. Thirty-nine patients developed CS-CMV infection (viral syndrome, n = 1; end-organ disease, n = 9; and asymptomatic viremia, n = 29). A nonreactive or indeterminate QFCMV result using the standard threshold around day 30 (but not before transplant) was associated with CS-CMV rates of 50% and 75%, respectively. A higher QFCMV threshold for reactivity (>1.0 IU interferon-γ/mL) outperformed the manufacturer's standard (>0.2 IU interferon-γ/mL) in predicting protection but still allowed a 16% incidence of CS-CMV. The combination of recipient age and type of donor, along with posttransplant QFCMV resulted in a prediction model that increased the negative predictive value from 84% (QFCMV alone) to 93%. QFCMV-guided preemptive therapy was of lower cost than preemptive therapy alone ( P < 0.001, probabilistic sensitivity analysis) and was cost-effective (incremental net monetary benefit of 210 USD) assuming willingness-to-pay of 2000 USD to avoid 1 CMV disease. Guided CMV prevention by the prediction model with QFCMV is cost-effective and would spare from CMV surveillance in 42% of patients with low risk for CS-CMV.

Using a commercially available assay that measures cytomegalovirus (CMV)-specific T-cell immunity to predict protection against CMV: A prospective, blinded clinical study

The Viracor CMV-T-cell immunity Panel (TCIP) measures %CMV-specific CD4+ and CD8+ T-cells. In this blinded clinical study, we evaluated the performance of the TCIP in predicting CMV events. Prospectively enrolled donor or recipient CMV-seropositive kidney transplant recipients (KTR) were evaluated with monthly TCIP testing until either discontinuation of valganciclovir prophylaxis or CMV DNAemia prompting treatment initiation. Also, prospectively enrolled KTR with low-level untreated DNAemia or after completion of treatment were evaluated for progression or relapse of CMV infection. Among 46 KTR, those with CMV events had significantly lower %CMV-specific CD8+ T-cells (p = 0.024), and the CMV protection ROC AUC was significant (AUC 0.78, p = 0.026). The positive predictive values of CD4+ and CD8+ T-cell positivity >0.2 % for CMV protection were: 96.3 % for CMV DNAemia prompting treatment initiation, 92.6 % for any DNAemia, 100 % for DNAemia >1000 IU/mL. The TCIP could be a useful adjunct tool in individualized management of CMV infection.

Dynamics and Clinical Significance of Cytomegalovirus-Specific Neutralizing Antibodies in Kidney Transplant Recipients Treated with T-Cell-Depleting Agents.

We measured cytomegalovirus (CMV)-specific antibodies that neutralize epithelial cell infection (CMV-AbNEIs) in 101 CMV-seropositive kidney transplant recipients (KTRs) at baseline and posttransplant months 3 and 6. All the patients received antithymocyte globulin and 3-month valganciclovir prophylaxis. There were no significant differences in pretransplant AbNEIs titers between KTRs that developed or did not develop any-level CMV infection or the composite of high-level infection and/or disease. One-year CMV infection-free survival was comparable between KTRs with or without pretransplant CMV-AbNEIs. No differences were observed by months 3 and 6. We observed no protective role for CMV-AbNEIs among CMV-seropositive KTRs undergoing T-cell-depleting induction.

Comparison of intracellular cytokine staining versus an ELISA-based assay to assess CMV-specific cell-mediated immunity in high-risk kidney transplant recipients.

The best method for monitoring cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) among high-risk kidney transplant (KT) recipients remains uncertain. We assessed CMV-CMI by intracellular cytokine staining (ICS) by flow cytometry and a commercial interferon (IFN)-γ release assay (QuantiFERON®-CMV [QTF-CMV]) at posttransplant months 3, 4, and 5 in 53 CMV-seropositive KT recipients that had received induction therapy with antithymocyte globulin (ATG) and a 3-month course of valganciclovir prophylaxis. The discriminative capacity (areas under receiver operating characteristics curve [auROCs]) and diagnostic accuracy to predict immune protection against CMV infection from the discontinuation of prophylaxis to month 12 were compared between both methods. There was significant although moderate correlations between CMV-specific IFN-γ-producing CD8+ T-cell counts enumerated by ICS and IFN-γ levels by QTF-CMV at months 3 (rho: 0.493; p = 0.005) and 4 (rho: 0.440; p = 0.077). The auROCs for CMV-specific CD4+ and CD8+ T-cells by ICS were nonsignificantly higher than that of QTF-CMV (0.696 and 0.733 vs. 0.678; p = 0.900 and 0.692, respectively). The optimal cut-off of ≥0.395 CMV-specific CD8+ T-cells yielded a sensitivity of 86.4%, specificity of 54.6%, positive predictive value of 79.2% and negative predictive value of 66.7% to predict protection. The corresponding estimates for QTF-CMV (IFN-γ levels ≥0.2 IU/mL) were 78.9%, 37.5%, 75.0%, and 42.9%, respectively. The enumeration of CMV-specific IFN-γ-producing CD8+ T-cells at the time of cessation of prophylaxis performed slightly better than the QTF-CMV assay to predict immune protection in seropositive KT recipients previously treated with ATG.

Transition from antigenemia to quantitative nucleic acid amplification testing in cytomegalovirus-seropositive kidney transplant recipients receiving preemptive therapy for cytomegalovirus infection

Due to the high costs, the strategy to reduce the impact of cytomegalovirus (CMV) after kidney transplant (KT) involves preemptive treatment in low and middle-income countries. Thus, this retrospective cohort study compared the performance of antigenemia transitioned to quantitative nucleic acid amplification testing, RT-PCR, in CMV-seropositive KT recipients receiving preemptive treatment as a strategy to prevent CMV infection. Between 2016 and 2018, 363 patients were enrolled and received preemptive treatment based on antigenemia (n = 177) or RT-PCR (n = 186). The primary outcome was CMV disease. Secondarily, the CMV-related events were composed of CMV-infection and disease, which occurred first. There were no differences in 1-year cumulative incidence of CMV-disease (23.7% vs. 19.1%, p = 0.41), CMV-related events (50.8% vs. 44.1%, p = 0.20), neither in time to diagnosis (47.0 vs. 47.0 days) among patients conducted by antigenemia vs. RT-PCR, respectively. The length of CMV first treatment was longer with RT-PCR (20.0 vs. 27.5 days, p < 0.001), while the rate of retreatment was not different (14.7% vs. 11.8%, p = 0.48). In the Cox regression, acute rejection within 30 days was associated with an increased the risk (HR = 2.34; 95% CI = 1.12–4.89; p = 0.024), while each increase of 1 mL/min/1.73 m2 of 30-day eGFR was associated with a 2% reduction risk of CMV-disease (HR = 0.98; 95% CI = 0.97–0.99; p = 0.001). In conclusion, acute rejection and glomerular filtration rate are risk factors for CMV disease, showing comparable performance in the impact of CMV-related events between antigenemia and RT-PCR for preemptive treatment.

QuantiFERON-Cytomegalovirus Assay for Prediction of Cytomegalovirus Viremia in Kidney Transplant Recipients: Study From High Cytomegalovirus Seroprevalence Country.

BackgroundEarly studies showed the utility of pretransplant QuantiFERON-Cytomegalovirus (QF-CMV) assays for CMV-disease prediction post kidney transplant (KT). However, recent data are conflicting.MethodsThis prospective cohort study enrolled adult patients undergoing KT between July 2017 and May 2019. Patients with antithymocyte globulin therapy or negative pretransplant CMV IgG were excluded. QF-CMV assays were performed on transplantation day and one month thereafter, and CMV viral loads were obtained 1, 3, and 6 months posttransplantation. The primary outcome was CMV viremia within 6 months. The QF-CMV assay–posttransplant CMV viremia association was analyzed.Results Fifty-five patients were enrolled (male, 58.2%; mean (SD) age, 46.5 (10.2) years). Fifty-two (94.5%) received CMV-seropositive donor kidneys. Over 6 months, 29 patients developed CMV viremia (52.7%), with 14 (25.5%) having significant viremia requiring antiviral therapy. The CMV-viremia incidence of patients with nonreactive and reactive baseline QF-CMV assays did not differ significantly (55.3% and 47.1%; p = 0.573). Among patients with reactive pretransplant QF-CMV assays, there was a trend toward a lower incidence of CMV viremia for those who were persistently reactive at 1 month after KTs, although there was no statistically significant difference (50% vs 83%; p = 0.132).ConclusionsOur study could not support the use of single-timepoint pretransplant or 1-month posttransplant QF-CMV assays as a predictor for posttransplant CMV viremia in CMV seropositive KT recipients. Investigation of the association between dynamic QF-CMV-status changes and CMV-viremia incidence are needed.

Associations of high anti-CMV IgG titer with renal function decline and allograft rejection in kidney transplant patients.

An anti-cytomegalovirus (CMV) immunoglobulin G (IgG) antibody is produced after primary CMV infection and generally persists after the primary infection. However, it is not well-known about the relationship between anti-CMV IgG titer and outcomes in kidney transplant recipients. We, therefore, aimed to explore the role of anti-CMV IgG titer on the risks of CMV disease development, allograft rejection, renal function decline, and mortality. In a hospital-based study, we identified 179 CMV-seropositive kidney transplant recipients between January 2013 and December 2017. These patients were divided into low and high anti-CMV IgG titer groups, respectively. The cutoff level of anti-CMV IgG titer was determined by receiver operating characteristic curve analysis. The outcomes evaluated included CMV disease, decrease of ≥15% in estimated glomerular filtration rate (eGFR), biopsy-proven allograft rejection, and all-cause mortality. The high anti-CMV IgG titer group (≥846.2 AU/mL) exhibited a higher risk of CMV disease (adjusted hazard ratio [aHR], 3.77; 95% CI, 1.47-9.68; p = 0.006), eGFR decline ≥15% (aHR, 2.00; 95% CI, 1.19-3.35; p = 0.009), and renal allograft rejection (aHR, 2.95; 95% CI, 1.11-7.87; p = 0.030) than the low titer group (<846.2 AU/mL). In kidney transplant recipients, a high anti-CMV IgG titer was associated with higher risks for developing CMV disease, undergoing allograft rejection, and eGFR decline.

Low-Dose Valganciclovir Prophylaxis Is Safe and Cost-Saving in CMV-Seropositive Kidney Transplant Recipients.

Introduction: Observational studies suggest that low-dose valganciclovir prophylaxis (450 mg daily for normal renal function) is as effective as and perhaps safer than standard-dose valganciclovir (900 mg daily) in preventing CMV infection among kidney transplant recipients. However, this practice is not supported by current guidelines due to concerns for breakthrough infection from resistant CMV, mainly in high-risk CMV donor-seropositive/recipient-seronegative kidney transplant recipients. Standard-dose valganciclovir is costly and possibly associated with higher incidence of neutropenia and BKV DNAemia. Our institution adopted low-dose valganciclovir prophylaxis for intermediate-risk (seropositive) kidney transplant recipients in January 2018. Research Question: To analyze the efficacy (CMV DNAemia), safety (BK virus DNAemia, neutropenia, graft loss, and death), and cost savings associated with this change. Design: We retrospectively compared the above outcomes between CMV-seropositive kidney transplant recipients who received low-dose and standard-dose valganciclovir, transplanted within our institution, between 1/19/2014 and 7/15/2019, using propensity score-adjusted competing risk analyses. We also compared cost estimates between the two dosing regimens, for 3 months of prophylaxis, and for different percentage of patient-weeks with normal renal function, using the current average wholesale price of valganciclovir. Results: We studied 179 CMV-seropositive kidney transplant recipients, of whom 55 received low-dose and 124 standard-dose valganciclovir. The majority received nonlymphocyte depleting induction (basiliximab). Low-dose valganciclovir was at least as effective and safe as, and more cost-saving than standard-dose valganciclovir. Conclusion: This single-center study contributes to mounting evidence for future guidelines to be adjusted in favor of low-dose valganciclovir prophylaxis in CMV-seropositive kidney transplant recipients.

Immunoguided Discontinuation of Prophylaxis for Cytomegalovirus Disease in Kidney Transplant Recipients Treated With Antithymocyte Globulin: A Randomized Clinical Trial.

Antiviral prophylaxis is recommended in cytomegalovirus (CMV)-seropositive kidney transplant (KT) recipients receiving antithymocyte globulin (ATG) as induction. An alternative strategy of premature discontinuation of prophylaxis after CMV-specific cell-mediated immunity (CMV-CMI) recovery (immunoguided prevention) has not been studied. Our aim was to determine whether it is effective and safe to discontinue prophylaxis when CMV-CMI is detected and to continue with preemptive therapy. In this open-label, noninferiority clinical trial, patients were randomized 1:1 to follow an immunoguided strategy, receiving prophylaxis until CMV-CMI recovery or to receive fixed-duration prophylaxis until day 90. After prophylaxis, preemptive therapy (valganciclovir 900 mg twice daily) was indicated in both arms until month 6. The primary and secondary outcomes were incidence of CMV disease and replication, respectively, within the first 12 months. Desirability of outcome ranking (DOOR) assessed 2 deleterious events (CMV disease/replication and neutropenia). A total of 150 CMV-seropositive KT recipients were randomly assigned. There was no difference in the incidence of CMV disease (0% vs 2.7%; P = .149) and replication (17.1% vs 13.5%; log-rank test, P = .422) between both arms. Incidence of neutropenia was lower in the immunoguided arm (9.2% vs 37.8%; odds ratio, 6.0; P < .001). A total of 66.1% of patients in the immunoguided arm showed a better DOOR, indicating a greater likelihood of a better outcome. Prophylaxis can be prematurely discontinued in CMV-seropositive KT patients receiving ATG when CMV-CMI is recovered since no significant increase in the incidence of CMV replication or disease is observed. NCT03123627.

Predictors of CMV Infection in CMV-Seropositive Kidney Transplant Recipients: Impact of Pretransplant CMV-Specific Humoral Immunity.

BackgroundAlthough cytomegalovirus (CMV)-seropositive solid organ transplant recipients have a relatively lower risk of CMV infection than CMV-seronegative recipients who receive allograft from CMV-seropositive donors, some patients remain at risk of CMV infection after transplant. We investigated the pretransplant CMV-specific humoral immunity (CHI) and other CMV infection predictors in CMV-seropositive kidney transplant (KT) recipients.MethodsThis retrospective study was conducted on adult CMV-seropositive KT recipients during 2017 and 2018. The cumulative incidence of CMV infection was estimated using the Kaplan-Meier method. CHI, measured with an enzyme-linked fluorescent immunoassay and other predictors for CMV infection, was analyzed using Cox proportional hazards models.ResultsOf the 340 CMV-seropositive KT recipients (37% female; mean ± SD age, 43 ± 11 years), 69% received deceased-donor allograft and 64% received induction therapy. During a mean follow-up of 14 months, the cumulative incidence of CMV infection was 14.8%. In multivariate analysis, low pretransplant CHI (defined as anti-CMV immunoglobulin [IgG] titer <20 AU/mL) was significantly associated with CMV infection (hazard ratio [HR], 2.98; 95% CI, 1.31–6.77; P = .009). Other significant predictors of CMV infection included older donor age (HR, 1.03; 95% CI, 1.01–1.06; P = .005), antithymocyte induction therapy (HR, 2.90; 95% CI, 1.09–7.74; P = .033), and prolonged cold ischemic time (HR, 1.06; 95% CI, 1.02–1.10; P = .002).ConclusionsA low pretransplant CHI is independently associated with post-transplant CMV infection in CMV-seropositive KT recipients. A quantitative anti-CMV IgG assay could potentially stratify CMV-seropositive patients at risk of CMV infection after KT.

1106. The incidence and risk factors associated with varicella zoster virus infection in kidney transplant recipients after 1-month acyclovir prophylaxis in a CMV preemptive therapy era

BackgroundVaricella zoster virus (VZV) infection is a well-known opportunistic infection in solid organ transplant recipients. Since the various strategies of the use of anti-herpetic drugs including ganciclovir or acyclovir have evolved, the epidemiology of VZV infection is changing. However, there are limited data on the recent incidence and risk factors of post-transplant VZV infection in popular preemptive ganciclovir era for CMV infection. We evaluated the incidence, risk factors and clinical characteristic of patients with development of post-transplant VZV infection in kidney transplant (KT) recipients after 1-month acyclovir prophylaxis in the hospital that adopted preemptive ganciclovir therapy for CMV infection.MethodsAll adult patients with seropositive CMV antibody admitted to a KT unit from January 2014 to December 2017 were retrospectively reviewed in a tertiary-care hospital in South Korea. Our hospital adopted preemptive ganciclovir therapy for CMV infection in all CMV seropositive KT recipients. We administered acyclovir prophylaxis for 1-month to CMV seropositive KT recipients. The primary endpoint was VZV infection development after KT.ResultsA total of 1295 KT recipients was followed up for 4295.8 person-years. The median follow-up period was 46.6 months (interquartile range (IQR) 34.3-59.5). Of the 1295 recipients, 100 (7.7%, 2.33 per 100 person-years, 95% confidence interval (CI) 1.89-2.83) patients developed VZV infection after KT. The median time for VZV infection development was 9.5 months (IQR 4.7-22.1). All patients had VZV-associated skin lesion, 9 postherpetic neuralgia, 2 visceral involvement and 3 disseminated infection. Of 100 patients, 16 patients need hospitalization due to VZV infection. In multivariate analysis, deceased donor KT (Hazard ratio (HR) 1.6; 95% CI 1.0-2.39, p = 0.05), mycophenolate maintenance immunosuppressive therapy (HR 0.3; 95% CI 0.14-0.75, p = 0.01) and rejection episode (HR 0.31; 95% CI 0.14-0.71, p = 0.01) were independently associated with VZV infection development after KT.ConclusionAbout one tenth of CMV seropositive KT recipients developed zoster after 1-month ACV prophylaxis during CMV preemptive strategy, especially in those who received deceased donor KT, mycophenolate therapy, and rejection episodes.Disclosures All Authors: No reported disclosures

1198. Measurement of Pre-transplant Anti-cytomegalovirus (CMV) Immunoglobulin G Titer to Predict Risk of CMV Infection in CMV-seropositive Kidney Transplant Recipients

BackgroundAlthough cytomegalovirus (CMV)-seropositive solid organ transplant recipients have a lower risk of CMV infection compared with CMV-seronegative recipients, some patients remain at risk of CMV infection after transplant. Low pre-transplant anti-CMV immunoglobulin G (IgG) titer has been reported as a predictor of CMV infection in CMV-seropositive liver and heart transplant recipients, but this association in CMV-seropositive kidney transplant (KT) recipients has not been explored. We investigated the pre-transplant anti-CMV IgG titer and other CMV infection risk factors in CMV-seropositive KT recipients.MethodsThis retrospective study was conducted on CMV-seropositive KT recipients aged >18 years old at Ramathibodi Hospital during 2017 and 2018. The cumulative incidence of CMV infection was estimated with Kaplan–Meier methodology. The pre-transplant anti-CMV IgG titer was measured with an enzyme-linked fluorescent immunoassay. Risk factors for CMV infection were analyzed with Cox proportional hazards models.ResultsOf the 340 included CMV-seropositive KT recipients (37% female; age [mean±SD]: 43±11 years), 69% and 64% received deceased-donor allograft and induction therapy, respectively. The anti-CMV IgG titer was < 20 and >20 AU/ml in 7.1% and 92.9% of patients, respectively. During a mean follow-up of 14 months, the cumulative incidence of CMV infection was 14.8%, including both asymptomatic CMV infection (69%) and tissue-invasive disease (31%). A pre-transplant anti-CMV IgG titer of < 20 AU/ml was significantly associated with CMV infection in both the univariate analysis (HR, 2.70; 95%CI, 1.21–6.05, [p=0.02]) and the multivariate analysis (HR, 2.98; 95% CI, 1.31–6.77, [p=0.009]). Other significant risk factors of CMV infection included older donor age (HR, 1.03; 95% CI, 1.01–1.06, [p=0.005]), anti-thymocyte induction therapy (HR, 2.90; 95% CI 1.09–7.74, [p=0.033]), and prolonged cold ischemic time (HR, 1.06; 95% CI, 1.02–1.10, [p=0.002]).ConclusionA low pre-transplant CMV-specific humoral immunity is independently associated with post-transplant CMV infection in CMV-seropositive KT recipients. The universally available anti-CMV IgG titer test could potentially stratify those at risk and target preventive strategy appropriately.Disclosures All Authors: No reported disclosures

Pretransplant CMV-Specific T-Cell Immunity But Not Dose of Antithymocyte Globulin Is Associated With Recovery of Specific Immunity After Kidney Transplantation.

This is a prospective, multicenter, observational study in cytomegalovirus (CMV)-seropositive kidney transplant recipients with pretransplant CMV-specific cell-mediated immunity (CMV-CMI) receiving antithymocyte globulin (ATG). We aimed to investigate posttransplant CMV-CMI over time and the impact of the dose-dependent ATG. CMV-CMI was assessed at days +30, +45, +60, and +90 after transplantation with the QuantiFERON-CMV assay. A reactive result (interferon-γ [IFN-γ] ≥ 0.2 IU/mL) indicated a positive CMV-CMI. A total of 78 positive CMV-CMI patients were enrolled in the study, of which 59.5% had a positive CMV-CMI at day +30 and 82.7% at day +90. Multivariate logistic regression analysis showed that ATG dose was not associated with positive CMV-CMI at any point. However, pretransplant IFN-γ level (>12 IU/mL vs ≤12 IU/mL) was associated with positive CMV-CMI at day +30 (odds ratio, 12.9; 95% confidence interval, 3.1-53.3; P < .001). In addition, all the patients who did not recover CMV-CMI at day +90 had a pretransplant IFN-γ level ≤12 IU/mL. More than half of CMV-seropositive kidney transplant recipients receiving ATG recover (or maintain) CMV-CMI by the first month after transplantation. The pretransplant IFN-γ level, but not the ATG dose, shows a strong association with the kinetics of this recovery.

Monitoring of CMV-specific cell-mediated immunity with a commercial ELISA-based interferon-γ release assay in kidney transplant recipients treated with antithymocyte globulin.

Monitoring for cytomegalovirus (CMV)-specific cell-mediated immunity (CMV-CMI) may be useful for individualizing valganciclovir (VGCV) prophylaxis after kidney transplantation (KT). We performed a commercial ELISA-based interferon (IFN)-γ release assay (QTF-CMV) from posttransplant months 2-5 (362 points) in 120 CMV-seropositive KT recipients that received antithymocyte globulin as induction therapy and VGCV prophylaxis (median of 92days). Forty-seven patients (39.3%) had CMV infection after discontinuation of prophylaxis. The QTF-CMV assay was reactive, nonreactive, and indeterminate in 264 (72.9%), 90 (24.9%), and 8 points (2.2%). The QTF-CMV assay at prophylaxis discontinuation exhibited suboptimal accuracy for predicting protective CMV-CMI (sensitivity: 77.4%; specificity: 34.3%; positive predictive value [PPV]: 64.1%; negative predictive value [NPV]: 50.0%), with no differences in 1-year CMV infection rates between patients with negative (nonreactive or indeterminate) or reactive results (45.8% vs 36.1%; P=.244). Specificity and PPV to predict protective CMV-CMI improved by elevating the IFN-γ cutoff value to 1.13IU/mL (65.7% and 71.4%) and 7.0IU/mL (85.7% and 76.2%), although NPVs decreased. The QTF-CMV assay as per manufacturer's interpretative criteria performed poorly to predict protection from CMV infection following discontinuation of VGCV prophylaxis among ATG-treated CMV-seropositive KT recipients. This performance is slightly improved by modifying the IFN-γ positivity threshold.

Pre-transplant assessment of pp65-specific CD4 T cell responses identifies CMV-seropositive patients treated with rATG at risk of late onset infection

Assessment of CMV-specific T cell immunity might be a useful tool in predicting CMV infection after solid organ transplantation. We have investigated CD4 and CD8 T-cell responses to CMV pp65 and IE-1 antigens in a prospective study of 28 CMV-seropositive kidney transplant recipients who were administered lymphocyte-depleting antibodies (Thymoglobulin®) as induction treatment and with universal prophylaxis for CMV infection. The response was analyzed by intracellular flow cytometry analysis of IFN-γ production in pretransplant samples and at 1, 6, 12 and 24 months post-transplant. Overall, only pretransplant CD4 T-cell responses to pp65 were significantly lower (p = .004) in patients with CMV replication post-transplant. ROC curve analysis showed that pre-transplant frequencies of pp65-specific CD4 + T cells below 0.10% could predict CMV infection with 75% sensitivity and 83.33% specificity (AUC: 0.847; 95% CI: 0.693–1.001; p = .0054) and seem to be mandatory for efficient control of CMV viral replication by the host immune system. In conclusion, the functional assessment of CMV-specific CD4 T-cell immunity pretransplant in seropositive patients may allow the identification of Thymoglobulin®-treated kidney transplant recipients at risk of developing CMV infection post-transplantation.

Age matters: older age as a risk factor for CMV reactivation in the CMV serostatus-positive kidney transplant recipient.

Evaluate risk factors for cytomegalovirus (CMV) reactivation during the first year after kidney transplantation in the CMV-seropositive older recipient. Retrospective single-center study. Between 2011 and 2015, 91 patients ≥ 65 years received a kidney transplant; these were matched with 91 controls, aged 40-60. Risk of CMV reactivation in the CMV-seropositive recipients was analyzed. Sixty-three older and 54 younger recipients were included; 50% had received CMV-directed prophylaxis. CMV reactivation was significantly more frequent in the older group (71.4% vs 44.4%, p = 0.003) and occurred earlier (p = 0.003). A multivariate model showed that only age was associated with CMV reactivation (OR 2.48, p = 0.03). After excluding patients that received thymoglobulin, older age group remained the only risk factor of CMV reactivation (OR 3.81, p = 0.014). Recurrent event analysis showed that the older cohort had an HR of 1.94 (p = 0.01) of CMV viremia; there was significant episode-cohort interaction (p < 0.01). While the older group had a higher risk of infection (HR = 2.43), after the initial episode the relative hazards were approximately equal (HR = 1.08, at period 2). This suggests that it is key to specifically avoid the first episode of reactivation. Universal prophylaxis or a hybrid prophylaxis model should be considered in the CMV-seropositive kidney transplant recipient aged ≥ 65 years.

1749. A Nationwide Survey of Cytomegalovirus Prevention Strategies in Kidney Transplant Recipients in a Resource-Limited Setting

BackgroundCytomegalovirus (CMV) causes morbidity in kidney transplant (KT) recipients. Strategies to prevent this infection in resource-limited settings have been unreliably implemented and under-explored. We investigated CMV prevention strategies utilized among transplant centers in Thailand.MethodsA questionnaire on CMV prevention strategies for KT recipients was developed using a web-based electronic survey website (www.surveymonkey.com). The survey was delivered to 31 transplant centers in Thailand. One infectious disease physician (ID) and one nephrologist (NP) from each center were included.ResultsThere were 43 respondents from 26 (84%) transplant centers including 26 (60%) IDs and 17 (40%) NPs. The majority worked in a public hospital setting (63%) and had encountered KT recipients for at least 2 years (74%). Forty-one (98%) physicians agreed on the necessity of CMV prevention. Of these, 34 (81%) physicians implemented prevention strategies for their patients. Interventions included preemptive approaches (47%), prophylaxis (44%), hybrid approaches (3%); surveillance after prophylaxis (3%), and CMV-specific immunity-guided approaches (3%). For CMV-seropositive KT recipients, use of preemption (84%) exceeded prophylaxis (12%). However, 81% of the former preferred targeted prophylaxis in patients receiving anti-thymocyte globulin therapy. Sixty-five and 93% of physicians started preemptive therapy when plasma CMV DNA loads reached 2,000 and 3,000 copies/mL (1,820 and 2,730 IU/mL), respectively. A significantly greater percentage of NPs initiated preemptive therapy at a plasma CMV level of 1,820 IU/mL compared with IDs (88% vs. 50%, [P = 0.02]). The most common barrier to prevention strategy implementation was financial inaccessibility of oral valganciclovir (67%) and quantitative CMV DNA testing (12%). The majority (81%) felt that a guideline would allow physicians to implement CMV prevention strategies for their patients.ConclusionMost physicians agreed on a need for preemptive approaches, although prophylaxis was targeted in those receiving intense immunosuppression. Guidelines and financial accessibility could improve CMV prevention strategy implementation in Thai KT recipients.Disclosures All authors: No reported disclosures.

A Nationwide Survey of Cytomegalovirus Prevention Strategies in Kidney Transplant Recipients in a Resource-Limited Setting.

ObjectiveStrategies to prevent cytomegalovirus (CMV) infection in resource-limited settings have been under-explored. We investigated CMV prevention strategies utilized among transplant centers in Thailand.MethodA questionnaire on CMV prevention strategies for kidney transplant (KT) recipients was developed using a web-based electronic survey website (www.surveymonkey.com). The survey was delivered to 31 transplant centers in Thailand. One infectious disease physician (ID) and 1 nephrologist (NP) from each center were included.ResultsThere were 43 respondents from 26 of the 31 transplant centers (84%), including 26 (60%) IDs and 17 (40%) NPs. Forty-one 95% (41/43) physicians agreed on the necessity of CMV prevention. Of these, 77% (33/43) physicians implemented prevention strategies for their patients. Interventions included preemptive approaches (48%), prophylaxis (45%), hybrid approaches; surveillance after prophylaxis (3%), and CMV-specific immunity-guided approaches (3%). For CMV-seropositive KT recipients, use of preemptive approaches (84%) exceeded prophylaxis (12%). However, 81% of the former preferred targeted prophylaxis in patients receiving antithymocyte globulin therapy. Sixty-five percent and 93% of physicians started preemptive therapy when plasma CMV DNA loads reached 2000 and 3000 copies/mL (1820 and 2730 IU/mL), respectively. A significantly greater percentage of NPs initiated preemptive therapy at a plasma CMV DNA load of 1820 IU/mL compared with IDs (88% vs 50%; P = .02). The most common barrier to prevention strategy implementation was financial inaccessibility of oral valganciclovir (67%) and quantitative CMV DNA testing (12%).ConclusionsMost physicians agreed on a need for preemptive approaches, although prophylaxis was targeted in those receiving intense immunosuppression. The financial implication is the main barrier for CMV prevention in Thailand.

Regular monitoring of cytomegalovirus-specific cell-mediated immunity in intermediate-risk kidney transplant recipients: predictive value of the immediate post-transplant assessment

ObjectivePrevious studies on monitoring of post-transplant cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) are limited by single-centre designs and disparate risk categories. We aimed to assess the clinical value of a regular monitoring strategy in a large multicentre cohort of intermediate-risk kidney transplant (KT) recipients. MethodsWe recruited 124 CMV-seropositive KT recipients with no T-cell-depleting induction pre-emptively managed at four Spanish institutions. CMV-specific interferon-γ-producing CD4+ and CD8+ T cells were counted through the first post-transplant year by intracellular cytokine staining after stimulation with pp65 and immediate early-1 peptides (mean of six measurements per patient). The primary outcome was the occurrence of any CMV event (asymptomatic infection and/or disease). Optimal cut-off values for CMV-specific T cells were calculated at baseline and day 15. ResultsTwelve-month cumulative incidence of CMV infection and/or disease was 47.6%. Patients with pre-transplant CMV-specific CD8+ T-cell count <1.0 cells/μL had greater risk of CMV events (adjusted hazard ratio (aHR) 2.84; p 0.054). When the CMI assessment was performed in the immediate post-transplant period (day 15), the presence of <2.0 CD8+ T cells/μL (aHR 2.18; p 0.034) or <1.0 CD4+ T cells/μL (aHR 2.43; p 0.016) also predicted the subsequent development of a CMV event. In addition, lower counts of CMV-specific CD4+ (but not CD8+) T cells at days 60 and 180 were associated with a higher incidence of late-onset events. ConclusionsMonitoring for CMV-specific CMI in intermediate-risk KT recipients must be regular to reflect dynamic changes in overall immunosuppression and individual susceptibility. The early assessment at post-transplant day 15 remains particularly informative.

Kinetic of the CMV‐specific T‐cell immune response and CMV infection in CMV‐seropositive kidney transplant recipients receiving rabbit anti‐thymocyte globulin induction therapy: A pilot study

Some studies have suggested that rATG treatment may be associated with an increased incidence of CMV infection and delayed CMV immune response. However, the evidences supporting this matter are scarce. This study aims to characterize the kinetic of the CMV-specific T-cell immune response before and after rATG induction therapy and the relationship with the development of CMV infection in CMV-seropositive kidney transplant recipients. An observational prospective study of CMV-seropositive kidney transplant patients that received rATG induction therapy was performed. A pretransplant sample was obtained before the surgery to determine the CMV-specific immunity. CMV viral load (by PCR) and CMV-specific T-cell immune response (by flow cytometry) were determined during the follow-up at 0.5, 1, 2, 3, 6, and 12months post transplantation. A total of 23 patients were included in the study. CMV prophylaxis was administrated for a media of 90days after transplantation. At the end of follow-up, 18 (78.3%) patients had CMV-specific immunity with a median value of 0.31% CD8+ CD69+ INF-γ+ T cells at a median of 16weeks post transplantation. Five patients never acquired CMV-specific immunity. No statistically significant association between CMV infection and CMV-specific T-cell immune response (P=.086) was observed. However, patients with positive pretransplant CMV-specific immunity developed earlier immunity and achieved higher levels of CD8+ CD69+ INF-γ+ T-cell post-transplantation than patients with negative pretransplant immunity. CMV-specific immune monitoring in addition to CMV-serology may be useful to stratify patient's risk of CMV infection before transplantation.