The clinical impact of cytomegalovirus infection following allogeneic hematopoietic cell transplantation: Why the quest for meaningful prophylaxis still matters

Prior cytomegalovirus reactivation may lead to worse bacterial bloodstream infection outcomes in HSCT patients

BACKGROUND

Cytomegalovirus (CMV) reactivation is common after transplantation, and may further augment natural killer (NK) cell activity, which has a protective role through both innate and adaptive immune responses. Bacterial bloodstream infections (BBSIs) are a common cause of morbidity and mortality in patients following allo-HSCT. Therefore, we hypothesized that CMV reactivation might play a role in the outcomes of patients with BBSI after allo-HSCT.

OBJECTIVES

We investigated the role of CMV reactivation in the clinical outcomes of patients with BBSI after allo-HSCT.

STUDY DESIGN

A total of 101 BBSI patients (45 non-CMV reactivation [NCR] and 56 CMV reactivation [CR]) were included in the study following allo-HSCT. Clinical and laboratory findings were reviewed, and differences were tested using the Chi-square (χ2) test. Multivariate Cox regression analysis was used to calculate hazard ratios for between-group comparisons of clinical outcomes.

RESULTS

CMV reactivation had a negative prognostic impact on the clinical outcomes of BBSI patients following allo-HSCT with regard to the 1-year overall survival time (HR, 3.583; 95% CI, 1.347-9.533; P = 0.011). In 56 BBSI patients with CMV reactivation following allo-HSCT, the 1-year mortality among those in whom CMV was reactivated first (CRF) was significantly elevated (56.5% vs. 18.2%, P = 0.003) compared with patients in whom the BBSIs occurred first (BOF).

CONCLUSIONS

CMV reactivation in BBSI patients is related to higher mortality 1-year after allo-HSCT. Further studies on a larger cohort are needed to better understanding the mechanism of CMV reactivation influence.

Significance of Cytomegalovirus gB Genotypes in Adult Patients Undergoing Hematopoietic Stem Cell Transplantation: Insights from a Single-Centre Investigation

INTRODUCTION

Cytomegalovirus (CMV) infection is a major clinical issue after allogeneic hematopoietic stem cell transplantation (HSCT). The CMV envelope glycoproteins are key in viral pathogenesis; the glycoprotein B (gB) encoded by the UL55 gene might be an important determinant of viral virulence and disease severity marker in patients treated with allogeneic HSCT. Our aim was to investigate the molecular diversity of CMV gB and inquire into the associations between UL55 gene variations and clinical manifestations in adult patients treated with allogeneic HSCT.

RESULTS

The most prevalent genotypes were gB1 and gB4 (11/27, 40.7%). Patients with genotype gB1 infection had earlier platelet engraftment (p < 0.033) and less frequent minimal/measurable residual disease post HSCT than those without this genotype. Patients with gB4 glycoprotein infection had a significantly lower CD4+/CD8+ ratio at D90 (p < 0.026). Interestingly, patients with gB5 glycoprotein infection had shorter overall survival from base condition diagnosis (p < 0.042), as well as shorter overall survival after HSCT (p < 0.036). Acute GvHD was noted more frequently in those with mixed-genotype infection (p = 0.047).

MATERIAL AND METHODS

The study included fifty-nine adult patients treated with allogeneic HSCT. Peripheral venous blood was sampled typically per week, with detection of CMV performed by quantitative real-time PCR. Multiplex nested PCR was used to determine specific gB genotypes, which were then statistically compared vis-à-vis specific clinical variables.

CONCLUSIONS

Our study points to variations in the viral UL55 locus imparting both beneficial (earlier platelet engraftment, less frequent MRD post HSCT) and adverse effects (shorter overall survival, more frequent acute GvHD, less frequent 100% chimerism at day 90) to the transplanted host. Comprehensive molecular investigations are necessary to validate this apparent duality, as the potential benefits of CMV could perhaps be utilized for the benefit of the patient in the future.

Development of a highly cytotoxic, clinical-grade virus-specific T cell product for adoptive T cell therapy

At present, recipients of allogeneic hematopoietic stem-cells are still suffering from recurrent infections after transplantation. Infusion of virus-specific T cells (VST) post-transplant reportedly fights several viruses without increasing the risk of de novo graft-versus-host disease. This study targeted cytomegalovirus (CMV) for the development of an innovative approach for generating a very specific VST product following Good Manufacturing Practices (GMP) guidelines. We used a sterile disposable compartment named the Leukoreduction System Chamber (LRS-chamber) from the apheresis platelet donation kit as the starting material, which has demonstrated high levels of T cells. Using a combination of IL-2 and IL-7 we could improve expansion of CMV-specific T cells. Moreover, by developing and establishing a new product protocol, we were able to stimulate VST proliferation and favors T cell effector memory profile. The expanded VST were enriched in a closed automated system, creating a highly pure anti-CMV product, which was pre-clinically tested for specificity in vitro and for persistence, biodistribution, and toxicity in vivo using NOD scid mice. Our results demonstrated very specific VST, able to secrete high amounts of interferon only in the presence of cells infected by the human CMV strain (AD169), and innocuous to cells partially HLA compatible without viral infection.

Cytomegalovirus drug resistance mutations in transplant recipients with suspected resistance

Resistant CMV infections are challenging complications after SOT and HSCT. Prompt recognition of ARMs is imperative for appropriate therapy. 108 plasma samples from 96 CMV + transplant recipients with suspected resistance were analysed in CNM in a retrospective nationwide study from January 2018 to July 2022 for resistance genotyping. ARMs in UL97 and UL54 were found in 26.87% (18/67) and 10.60% (7/66) of patients, respectively. Patients' ARM distribution in UL97 was as follows: L595S n = 3; L595S/M460I n = 1; L595S/N510S n = 1; L595W n = 1; C603W n = 4; A594V n = 3; A594E n = 1; C607Y n = 1; L397R/T409M/H411L/M460I n = 1; L397I n = 1; H520Q n = 1; four patients showed ARMs in UL54 as well (F412C n = 1; T503I n = 2; P522S n = 1), whereas three patients exhibited ARMs in UL54 only (L501I/T503I/L516R/A834P n = 1; A987G n = 2). L516R in UL54 and L397R/I and H411L in UL97 have been found for the first time in a clinical sample. L595S/W was the most prevalent ARM found to lend resistance to GCV. In UL54 all ARMs lent resistance to GCV and CDV. In addition, A834P, found in one patient, also lent resistance to FOS. CMV load did not differ significantly in patients with or without ARMs, and no differences were found either between patients with ARMs in UL97 or in UL97 and UL54. Despite extensive use of classical antivirals for the treatment of CMV infection after HSCT and SOT, ARMs occurred mainly in viral UL97 kinase, which suggests that CDV and mostly FOS continue to be useful alternatives to nucleoside analogues after genotypic detection of ARMs.

Diagnostic stewardship to limit repeat plasma cytomegalovirus viral load testing

BACKGROUND

Frequent serial monitoring of plasma cytomegalovirus (CMV) viral load caused unnecessary budgets for laboratory testing without changes in treatment. We aimed to implement diagnostic stewardship to limit CMV viral load testing at appropriate intervals.

METHODS

A quasi-experimental study was performed. To avoid unnecessary plasma CMV viral load testing, the inpatient electronic pop-up reminder was launched in 2021. In cases with plasma CMV viral load testing was ordered in intervals of less than five days, telephone interview and feedback were performed. Pre-post intervention data was compared in terms of clinical and monetary outcomes. The rate of plasma CMV viral load testing performed in intervals of less than five days was compared between 2021 and 2019 using the Poisson regression model.

RESULTS

After the protocol implementation, there was a significant decrease in the rate of plasma CMV viral load test orders in intervals of less than five days from 17.5% to 8.0% [incidence rate ratio 0.40, p < 0.001]. There was no statistically significant difference in the incidence of CMV DNAemia and CMV disease (p = 0.407 and 0.602, respectively). As a result, the hospital could save the costs of plasma CMV viral load testing per 1,000 patients performed with intervals of less than five days from 2,646,048.11 to 1,360,062.89 Thai Baht.

CONCLUSIONS

The diagnostic stewardship program is safe and helpful in reducing unnecessary plasma CMV viral load testing and costs.

Analysis of Clinical Characteristics of Patients with Recurrent Cytomegalovirus Retinitis after Hematopoietic Stem Cell Transplantation

OBJECTIVE

To analyze and summarize the clinical and imaging characteristics of patients with cytomegalovirus retinitis (CMVR) relapse after hematopoietic stem cell transplantation (HSCT).

METHODS

This retrospective case series study recruited patients with CMVR after HSCT. The study compared the patients with stable lesions and CMV-negative aqueous humor after treatment with those with relapse lesions and a CMV DNA load in aqueous humor which had increased again after treatment. The observation indexes were basic clinical information, best-corrected visual acuity, wide-angle fundus photography, optical coherence tomography (OCT), blood CD4⁺ T lymphocyte count, and aqueous humor CMV load of the patients. We summarized the data and statistically analyzed the differences between the relapse and non-relapse groups, as well as the correlations of the observed indicators.

RESULTS

The study recruited 52 patients with CMVR (82 eyes) after HSCT, of whom 11 patients (15 eyes) had recurrence after treatment (21.2%). The recurrence interval was 6.4 ± 4.9 months. The final best-corrected visual acuity of recurrent patients was 0.3 ± 0.3. The number of CD4⁺ T lymphocytes in recurrence patients at the time of onset was 126.7 ± 80.2/mm³. The median CMV DNA load detected in aqueous humor at the time of recurrence was 8.63 × 10³ copies/mL. There was a significant difference in the CD4⁺ T lymphocyte count between the recurrence and the non-recurrence groups at onset. The onset of visual acuity in recurrence patients was significantly correlated with final visual acuity and recurrence lesion area. The fundus of recurred CMVR showed increased marginal activity of the original stable lesion. Concurrently, yellow-white new lesions appeared around the stable, atrophic, and necrotic lesions. OCT showed new diffuse hyperreflexic lesions in the retinal neuroepithelial layer near the old lesions. Inflammatory punctate hyperreflexes were observed in the vitreous, with vitreous liquefaction and contraction.

CONCLUSION

This study suggests that the clinical features, fundus manifestations, and imaging features of CMVR recurrence after HSCT are different from those at the initial onset. Patients should be closely followed up after their condition is stable to be alert for CMVR recurrence.

Population Pharmacokinetics of Ganciclovir in Allogeneic Hematopoietic Stem Cell Transplant Patients

Treatment of cytomegalovirus (CMV) infection in allogeneic hematopoietic stem cell transplantation (alloHCT) patients with ganciclovir is complicated by toxicity and resistance. This study aimed to develop an intravenous ganciclovir population pharmacokinetic model for post-alloHCT patients and to determine dosing regimens likely to achieve suggested therapeutic exposure targets. We performed a prospective observational single-center pharmacokinetic study in adult alloHCT patients requiring treatment with intravenous ganciclovir for CMV viremia or disease. Samples were analyzed using a validated ultraperformance liquid chromatography method. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using Pmetrics for R. Twenty patients aged 18 to 69 years were included in the study. A 2-compartment model with linear elimination from the central compartment and between occasion variability best described the data. Incorporating creatinine clearance (CLCR) estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and presence of continuous renal replacement therapy as covariates for ganciclovir clearance improved the model. Compared to current dosing recommendations, simulations demonstrated loading doses were required to achieve a target AUC24 of 80 to 120 mg.h/L on day 1 of induction therapy. Increased individualization of post-loading induction and maintenance doses based on CLCR is required to achieve the suggested exposures for efficacy (AUC24 >80/>40 mg.h/L for induction/maintenance) while remaining below the exposure thresholds for toxicity (AUC24 <120/<60 mg.h/L for induction/maintenance). Intravenous ganciclovir dosing in alloHCT patients can be guided by CLCR estimated by CKD-EPI. Incorporation of loading doses into induction dosing regimens should be considered for timely achievement of currently suggested exposures.

Effective CMV prophylaxis with high-dose valaciclovir in allogeneic hematopoietic stem-cell recipients at a high risk of CMV infection

BACKGROUND

Cytomegalovirus (CMV) infection increases mortality and morbidity following allogeneic hematopoietic stem-cell transplantation (alloHSCT). Universal antiviral prophylaxis with letermovir is effective but unsubsidized in Australia. Valaciclovir demonstrates anti-CMV activity in high doses, but few current real-world studies explore its use as primary prophylaxis in high-risk patients post-alloHSCT.

METHODS

We performed a retrospective analysis of alloHSCT recipients at high risk of clinically significant CMV infection (cs-CMVi), defined as a plasma CMV DNA viral load of >400 IU/ml requiring preemptive therapy, or CMV disease. High-risk recipients were CMV seropositive and underwent T-cell depleted, haploidentical or umbilical cord stem-cell transplants. Consecutive patients transplanted from July 2018 to January 2020, treated with valaciclovir 2 g TDS from day +7 to +100 (HD-VALA), were compared to a historical cohort (July 2017-June 2018) who only received preemptive CMV therapy, and standard valaciclovir (SD-VALA) for varicella/herpes prophylaxis. We compared incidence of and time to cs-CMVi.

RESULTS

In the SD-VALA cohort (n = 27, median CMV follow-up duration 259 days), 23/27 (85%) developed cs-CMVi at a median of 39 days. For the HD-VALA cohort (n = 35, median CMV follow-up duration 216 days), 19/35 (54%) developed cs-CMVi, at a median of 68 days. Time to cs-CMVi was significantly longer in HD-VALA cohort (p < .0001). On multivariate analysis, HD VALA reduced the risk of cs-CMVi (HR 0.32, p = .0005).

CONCLUSIONS

In alloHSCT recipients at high risk for cs-CMVi, HD-VALA resulted in lower cumulative reactivation, and delayed reactivation, reducing requirement for preemptive CMV therapy in the early post-engraftment period.

Molecular modelling of the HCMV IL-10 protein isoforms and analysis of their interaction with the human IL-10 receptor

The human cytomegalovirus (HCMV) UL111A gene encodes several homologs of the cellular interleukin 10 (cIL-10). Alternative splicing in the UL111A region produces two relatively well-characterized transcripts designated cmvIL-10 (isoform A) and LAcmvIL-10 (isoform B). The cmvIL-10 protein is the best characterized, both structurally and functionally, and has many immunosuppressive activities similar to cIL-10, while LAcmvIL-10 has more restricted biological activities. Alternative splicing also results in five less studied UL111A transcripts encoding additional proteins homologous to cIL-10 (isoforms C to G). These transcripts were identified during productive HCMV infection of MRC-5 cells with the high passage laboratory adapted AD169 strain, and the structure and properties of the corresponding proteins are largely unknown. Moreover, it is unclear whether these protein isoforms are able to bind the cellular IL-10 receptor and induce signalling. In the present study, we investigated the expression spectrum of UL111A transcripts in fully permissive MRC-5 cells and semi permissive U251 cells infected with the low passage HCMV strain TB40E. We identified a new spliced transcript (H) expressed during productive infection. Using computational methods, we carried out molecular modelling studies on the three-dimensional structures of the HCMV IL-10 proteins encoded by the transcripts detected in our work (cmvIL-10 (A), LAcmvIL-10 (B), E, F and H) and on their interaction with the human IL-10 receptor (IL-10R1). The modelling predicts clear differences between the isoform structures. Furthermore, the in silico simulations (molecular dynamics simulation and normal-mode analyses) allowed us to evaluate regions that contain potential receptor binding sites in each isoform. The analyses demonstrate that the complexes between the isoforms and IL-10R1 present different types of molecular interactions and consequently different affinities and stabilities. The knowledge about structure and expression of specific viral IL-10 isoforms has implications for understanding of their properties and role in HCMV immune evasion and pathogenesis.

Diagnosis and treatment for the early stage of cytomegalovirus infection during hematopoietic stem cell transplantation

Cytomegalovirus (CMV) infection remains a frequent complication after hematopoietic stem cell transplantation (HSCT) and causes significant morbidity and mortality in transplantation recipients. In this review, we highlight the role of major risk factors that are associated with the incidence of CMV infection. Advances in immunosurveillance may predict CMV infection, allowing early interventions to prevent severe infection. Furthermore, numerous therapeutic strategies against CMV infection after HSCT are summarized. A comprehensive understanding of the current situation of CMV treatment may provide a hint for clinical practice and even promote the development of novel strategies for precision medicine.

Risk factors and incidence of cytomegalovirus viremia and disease in pediatric patients with allogeneic hematopoietic stem cell transplantation: An 8-year single-center experience in Latin America

BACKGROUND

Cytomegalovirus infection represents a significant cause of morbidity and mortality after hematopoietic stem cell transplantation. This study aimed to evaluate the incidence of viremia and disease due to cytomegalovirus and the risk factors in pediatric patients with hematopoietic stem cell transplantation in our institution.

METHODS

This was a retrospective cohort of patients under 19 years of age who underwent allogeneic hematopoietic stem cell transplantation due to any indication between 2012 and 2019. The analysis included the diagnosis of cytomegalovirus viremia or disease during post-transplant follow-up, evaluation of risk factors, and outcomes. The statistical analysis included univariate and multivariate analyses, and the cumulative incidence of cytomegalovirus viremia was determined by the Kaplan-Meier method using STATA 14 statistical software.

RESULTS

A total of 182 transplants were included. At 100 days, the cumulative incidence of cytomegalovirus viremia was 70.5%, and that of cytomegalovirus disease was 4.7%. Overall survival at 2 years was 74%, and event-free survival was 64%. The remaining demographic characteristics were not predictors of infection. There was no association between viremia and relapse or survival of the patients. Higher mortality was noted in cytomegalovirus disease.

CONCLUSIONS

During the study period, the incidence of cytomegalovirus disease was similar to that of other pediatric reports, but the incidence of viremia was higher. Pre-emptive therapy has diminished disease rates and death due to infection. Viral load cutoff points should be standardized to guide treatment and avoid myelotoxicity.

Revisit of the Association between Cytomegalovirus Infection and Invasive Fungal Infection after Allogeneic Hematopoietic Stem Cell Transplantation: A Real-World Analysis from a High CMV Seroprevalence Area

Infection is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) especially cytomegalovirus (CMV) infection and invasive fungal infection (IFI). Taiwan is a high CMV seroprevalence area. Our study aimed to evaluate the incidence, risk factors, the impact on survival of CMV infection (including reactivation and disease) and the association of CMV infection and IFI in recipients after allo-HSCT during the first 100 days after transplantation. This was a retrospective study including 180 recipients of allo-HSCT. A total of 99 patients had CMV reactivation, and nine patients had CMV diseases. There were more mismatched donors, more ATG usage and more transplantation from CMV IgG-negative donor in patients with CMV reactivation. There was no survival difference in patients with or without CMV reactivation. A total of 34 patients had IFIs, and IFI after allo-HSCT was associated with significantly inferior survival. Patients with CMV reactivation did not increase the incidence of overall IFI, but they did result in more late-onset (>40 days) IFI (p = 0.056). In this study, we demonstrated real-world data of CMV infection and IFI from a high CMV seroprevalence area.

Acute Neurological Involvement after Donor Lymphocyte Infusion for Post-Transplant Viral Infection: The Same Pattern of Novel Cancer Immunotherapy-Related CNS Toxicity?

Early post-transplant is the critical phase for the success of hematopoietic stem cell transplantation (HSCT). New viral infections and the reactivations associated with complete ablation of the recipient's T-cell immunity and inefficient reconstitution of the donor-derived system represent the main risks of HSCT. To date, the pharmacological treatments for post-HSCT viral infection-related complications have many limitations. Adoptive cell therapy (ACT) represents a new pharmacological strategy, allowing us to reconstitute the immune response to infectious agents in the post-HSC period. To demonstrate the potential advantage of this novel immunotherapy strategy, we report three cases of pediatric patients and the respective central nervous system complications after donor lymphocyte infusion.

QuantiFERON-CMV to predict clinically significant CMV infection after allogeneic haematopoietic stem cell transplantation

BACKGROUND

Controlling CMV infection through prophylaxis or pre-emptive therapy remains an important contributor to outcomes after allogeneic haematopoetic stem cell transplant (alloHCT). Predicting clinically significant CMV infection (csCMVi) after day 100 remains a challenge.

METHODS

We examined the abilty of the QuantiFERON-CMV^® assay (QFN-CMV) at day 100 (d100) and day 150 (d150) after alloHCT to predict csCMVi after these time points, with median follow-up of 3.1 years (range 1.3 to 4.3 years).

RESULTS

In 46 transplants (D+R- = 12, D+R+ = 25, D-R+ = 9; matched related = 13, unrelated donor = 32, haploidentical = 1), for the prediction of freedom from csCMVi>d100, QFN-CMVd100 (positive compared to negative/indeterminate) had sensitivity 62% (23/37), specificity 100% (9/9), positive predictive value 100% (23/23), and negative predictive value 39% (9/23). For the prediction of freedom from csCMVi>d150, QFN-CMVd150 (positive compared to negative/indeterminate) had sensitivity 62% (18/29), specificity 83% (5/6), positive predictive value 95% (18/19), and negative predictive value 31% (5/16).

CONCLUSION

Positive QFN-CMV at d100 and d150 strongly predicted freedom from csCMVi after these time points. QFN-CMV could be utilised to predict the need for pre-emptive therapy and CMV viral load monitoring after day 100 post alloHCT. This article is protected by copyright. All rights reserved.

Association between the kinetics of cytomegalovirus reactivation in terms of the area under the curve of cytomegalovirus antigenemia and non-relapse mortality after allogeneic hematopoietic stem cell transplantation

BACKGROUND

We assessed the kinetics of cytomegalovirus (CMV) reactivation using the area under the curve (AUC), which simultaneously reflects both the viral load at each time point and the duration of CMV antigenemia (CMV-AG).

METHODS

We performed a single-institute retrospective analysis in patients who received allogeneic hematopoietic stem cell transplantation (HSCT) between 2007 and 2017 and survived more than 100 days after HSCT. The AUC of CMV-AG (CMV-AUC) was calculated by a trapezoidal method using the number of CMV-AG tested by the C10/C11 method after logarithmic transformation, and plotted weekly up to day 100.

RESULTS

CMV reactivation was observed in 195 cases and the median CMV-AUC for CMV-reactivated patients was 8.7 (range 0.5-30.7). Older age, corticosteroid administration, CMV-seropositive transplant recipients, HSCT from an unrelated donor, and underlying diseases were independent predictive factors for higher CMV-AUC. Higher CMV-AUC was associated with poor overall survival (OS) with borderline significance in a univariate analysis (p = .07), but was not significant in a multivariate analysis. Older age, high-risk disease status, and female gender were identified as significant factors associated with poor OS in this study. On the other hand, CMV-AUC (hazard ratio: no reactivation reference, low 0.98, high 2.49, p < .01), older age, HCT-CI ≥3, and corticosteroid administration were identified as significant factors associated with increased incidence of non-relapse mortality (NRM).

CONCLUSIONS

The kinetics of CMV reactivation in terms of CMV-AUC reflect both the severity and duration of CMV reactivation. High CMV-AUC was associated with an increased incidence of NRM in survivors over 100 days.

Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines-e.g., live-attenuated, chimeric, viral-based-and non-living ones-subunit, RNA-based, virus-like particles, plasmid-based DNA-have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV's capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

High dose valaciclovir to prevent cytomegalovirus infection in allogeneic haematopoietic stem cell transplant recipients

Cytomegalovirus (CMV) infection causes morbidity and mortality after allogeneic haematopoietic stem cell transplantation (HSCT). We investigated whether prophylaxis with high dose valaciclovir is effective at reducing the incidence of clinically significant CMV infection (csCMVi) within six months of allogeneic HSCT. Consecutive allogeneic HSCT recipients who received 2g valaciclovir orally four times daily from transplant until day 100 (prophylaxis group) were compared to subsequent patients who received no CMV prophylaxis (control group). Forty-nine patients in the prophylaxis group and 59 in the control group were included. The cumulative incidence of csCMVi at 6 months was 20% (95% confidence interval (CI): 9%-27%) in the prophylaxis group and 39% (95% CI: 26%-47%) in the control group (P = .009). There was no CMV disease in the prophylaxis group and three cases in the control group. There was no difference in time to neutrophil or platelet recovery nor graft failure between groups. On multivariable analysis, lack of high dose valaciclovir prophylaxis, positive recipient CMV IgG and age were associated with greater likelihood of csCMVi. There was no significant difference in acute graft versus host disease, non-relapse mortality or overall survival between groups. In this retrospective cohort study, high dose valaciclovir prophylaxis resulted in a lower incidence of csCMVi within six months of HSCT.

Prediction of Cytomegalovirus Reactivation by Recipient Cytomegalovirus-IgG Titer before Allogeneic Hematopoietic Stem Cell Transplantation

Recipient cytomegalovirus (CMV) seropositivity is known to be a risk factor for CMV reactivation after allogeneic hematopoietic stem cell transplantation (allo-HCT). We explored the association of CMV-IgG titer of recipients with CMV reactivation after allo-HCT and developed a model for predicting CMV reactivation for the purpose of identifying a high-risk group. In addition, we evaluated the impact of CMV-IgG titer on survival outcomes and acute graft-versus-host disease (GVHD). We retrospectively analyzed 309 patients who achieved neutrophil engraftment after allo-HCT and evaluated whether pretransplantation recipient CMV-IgG titer was associated with transplantation outcomes, including CMV reactivation. Using the best cutoff value determined by a receiver operating characteristic curve analysis, we divided the study cohort into 3 groups: high-titer, low-titer, and negative. CMV reactivation occurred most frequently in the high-titer group, followed by the low-titer and negative groups (81%, 37%, and 16%, respectively, at 180 days after allo-HCT; P < .01). In a multivariate analysis, recipient CMV-IgG titer was significantly associated with subsequent CMV reactivation (hazard ratio [HR], 9.31 in the high-titer group [P < .01] and 2.91 in the low-titer group [P = .023]). CMV diseases were observed exclusively in the high-titer group. Overall survival (OS) was lower in the high-titer group compared with the other 2 groups (2-year OS, 56%, 60%, and 80%, respectively; P = .075), whereas the cumulative incidences of grade II-IV acute GVHD, nonrelapse mortality (NRM), and relapse were not significantly different among the 3 groups. In multivariate analyses, CMV-IgG titer was not associated with increased risks of these outcomes, although CMV reactivation itself was identified as a risk factor for NRM (HR, 3.05; P = .002). Our data demonstrate that a higher titer of recipient CMV-IgG is predictive of CMV reactivation after allo-HCT. Further investigation is needed to determine how to apply these results to prophylactic or preemptive strategies against CMV, considering recipient CMV-IgG titer for effective risk stratification.

Is It Feasible to Use CMV-Specific T-Cell Adoptive Transfer as Treatment Against Infection in SOT Recipients?

During the last decade, many studies have demonstrated the role of CMV specific T-cell immune response on controlling CMV replication and dissemination. In fact, it is well established that transplanted patients lacking CMV-specific T-cell immunity have an increased occurrence of CMV replication episodes and CMV-related complications. In this context, the use of adoptive transfer of CMV-specific T-cells has been widely investigated and applied to Hematopoietic Stem Cell Transplant patients and may be useful as a therapeutic alternative, to reconstitute the CMV specific T-cell response and to control CMV viremia in patients receiving a transplantation. However, only few authors have explored the use of T-cell adoptive transfer in SOT recipients. We propose a novel review in which we provide an overview of the impact of using CMV-specific T-cell adoptive transfer on the control of CMV infection in SOT recipients, the different approaches to stimulate, isolate and expand CMV-specific T-cells developed over the years and a discussion of the possible use of CMV adoptive cellular therapy in this SOT population. Given the timeliness and importance of this topic, we believe that such an analysis will provide important insights into CMV infection and its treatment/prevention.

[Pediatric expert consensus on the application of intravenous immunoglobulin in children with hematological/neoplastic diseases]

Intravenous immunoglobulin (IVIG) has been widely used in chemotherapy for hematological malignancies, targeted therapy, and hematopoietic stem cell transplantation; however, there are still no available guidelines or consensus statements on the application of IVIG in pediatric hematological/neoplastic diseases at present in China and overseas. This consensus is developed based on the research advances in the application of IVIG in pediatric hematological/neoplastic diseases across the world and provides detailed recommendations for the clinical application of IVIG in pediatric hematological/neoplastic diseases and the prevention and treatment of related adverse reactions.

Preventing Infection by Human Cytomegalovirus

The way to a successful vaccine against human cytomegalovirus is hampered by the peculiar biology of this infection. However, some candidate vaccines have been shown to protect seronegative women and transplant recipients, and we should know soon whether they can prevent congenital infection.

A Systematic Review of the Clinical Pharmacokinetics, Pharmacodynamics and Toxicodynamics of Ganciclovir/Valganciclovir in Allogeneic Haematopoietic Stem Cell Transplant Patients

BACKGROUND

Ganciclovir (GCV) and valganciclovir (VGCV) are the first-line agents used to prevent and treat cytomegalovirus (CMV) infection in allogeneic haematopoietic stem cell transplant (alloHCT) patients.

OBJECTIVE

The aim of this work was to describe available data for the clinical pharmacokinetics, pharmacodynamics and toxicodynamics of GCV and VGCV and the potential of a therapeutic drug monitoring strategy to improve outcomes in the alloHCT population.

METHODS

We systematically reviewed the pharmacokinetics (dose-exposure), pharmacodynamics (exposure-efficacy) and toxicodynamics (exposure-toxicity) of GCV and VGCV in alloHCT patients with CMV infection. Studies including alloHCT patients treated for CMV infection reporting the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV or VGCV were searched for using the PUBMED and EMBASE databases from 1946 to 2019. Only studies involving participants > 12 years of age and available in the English language were included.

RESULTS

A total of 179 patients were included in the 14 studies that met the inclusion criteria, of which 6 examined GCV pharmacokinetics only, while 8 also examined GCV pharmacodynamics and toxicodynamics. Reported pharmacokinetic parameters showed considerable interpatient variability and were different from other populations, such as solid organ transplant and human immunodeficiency virus-infected patients. Only one study found a correlation between neutropenia and elevated peak and trough GCV concentrations, with no other significant pharmacodynamic and toxicodynamic relationships identified. While therapeutic drug monitoring of GCV is performed in some institutions, no association between GCV therapeutic drug monitoring and clinical outcomes was identified.

CONCLUSION

Further studies of the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV/VGCV in alloHCT patients are required to identify a more robust therapeutic range and to subsequently quantify the potential value of therapeutic drug monitoring of GCV/VGCV in the alloHCT population.

Early T cell reconstitution and cytokine profile may help to guide a personalized management of human cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Human cytomegalovirus (HCMV) infection is one of the major causes of mortality and morbidity after allo-hematopoietic stem cell transplantation (HSCT). Antiviral therapies are associated with toxicity and high economic burden. The aim of this retrospective study was to identify allo-HSCT HCMV-seropositive recipients at low risk of clinically significant HCMV infection who could avoid antiviral therapies. Sixty adult patients who underwent allo-HSCT were clustered in two groups: i) 22 (37%) spontaneously controlling HCMV reactivation (Controllers); ii) 38 (63%) developing clinically significant HCMV infection and receiving pre-emptive therapy (Non-Controllers). We analyzed several patient baseline characteristics, total/HCMV-specific CD4⁺ and CD8⁺ T-cell counts and their cytokine production (IFNγ, TNFα, IL2). Controllers presented a higher number of total/HCMV-specific CD4⁺ and CD8⁺ T-cells (P=0.001 and P=0.017 for total CD4⁺ and CD8⁺ T-cells respectively; P<0.001 for HCMV-specific T-cells) and a lower percentage of mono-functional IFNγ-producing HCMV-specific CD8⁺ T-cells (P=0.002). In bi-variable models, the prognostic impact of the percentage of mono-functional HCMV-specific CD8⁺ T-cells on treatment-free survival, adjusted for total/HCMVspecific CD4⁺ and CD8⁺ T-cells, was confirmed. An HCMV-seronegative donor was the only baseline characteristic associated with a clinically significant infection. These data, when confirmed by a larger prospective study, may provide information for guiding the personalized management of HCMV infection in allo-HSCT recipients.

How I treat CMV reactivation after allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) reactivation remains one of the most common and life-threatening infectious complications following allogeneic hematopoietic stem cell transplantation, despite novel diagnostic technologies, several novel prophylactic agents, and further improvements in preemptive therapy and treatment of established CMV disease. Treatment decisions for CMV reactivation are becoming increasingly difficult and must take into account whether the patient has received antiviral prophylaxis, the patient's individual risk profile for CMV disease, CMV-specific T-cell reconstitution, CMV viral load, and the potential drug resistance detected at the time of initiation of antiviral therapy. Thus, we increasingly use personalized treatment strategies for the recipient of an allograft with CMV reactivation based on prior use of anti-CMV prophylaxis, viral load, the assessment of CMV-specific T-cell immunity, and the molecular assessment of resistance to antiviral drugs.

Cost-effectiveness of letermovir as cytomegalovirus prophylaxis in adult recipients of allogeneic hematopoietic stem cell transplantation in Hong Kong

BACKGROUND

The cost-effectiveness of letermovir as cytomegalovirus (CMV) prophylaxis in adult seropositive patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT), compared with the conventional strategy of preemptive treatment, has not been evaluated in Asia.

METHODS

A decision analytical model, simulating the clinical progression of CMV infection on a lifetime horizon, was developed to compare prophylactic strategy with letermovir with preemptive therapy alone as anti-CMV strategies. Prophylaxis comprised administering letermovir for 14 weeks, with clinical outcomes measured at 24 weeks, followed by preemptive therapy if CMV infection occurred. This approach was modeled on outcomes of the letermovir phase 3 clinical study. The model enumerated the cost of letermovir prophylaxis, quality-adjusted life years (QALYs), and incremental cost per QALYs gained with prophylaxis. The opposite arm involved regular monitoring and preemptive therapy for CMV reactivation. Real-world costs from the adult HSCT center at Queen Mary Hospital, Hong Kong, were adopted for analysis. Costs and clinical benefits, expressed as QALYs, were discounted at 3% per year.

RESULTS

Letermovir prophylaxis compared with preemptive therapy only would lead to an increase of life-year and QALYs at increased costs. Incremental cost-effectiveness analysis showed that letermovir prophylaxis had an associated cost of HKD 193,580 for each life-year gained, and HKD 234,675 for each QALY gained. Probabilistic sensitivity analysis showed that the majority of incremental cost-effectiveness ratio fell below the cost-effectiveness threshold of HKD 382,046 (one gross domestic product per capita) per QALY gained.

CONCLUSIONS

Letermovir prophylaxis would be cost-effective for preventing CMV infection in adult seropositive allogeneic HSCT recipients in Hong Kong.

"Mini" bank of only 8 donors supplies CMV-directed T cells to diverse recipients

Cytomegalovirus (CMV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT), and standard antiviral therapies are associated with significant side effects and development of drug-resistant mutants. Adoptively transferred donor-derived CMV-specific T cells (CMVSTs) can provide an alternative treatment modality with few side effects but are not widely available due to their patient-specific nature. Here we report the establishment and use of a bank of CMVSTs derived from just 8 CMV-seropositive donors, with HLA types representing the diverse US population, as an "off-the-shelf" therapy to treat drug-refractory infections. To date, we have screened 29 patients for study participation and identified a suitable line, with ≥2 of 8 shared HLA antigens, for 28 (96.6%) patients with a median of 4 shared HLA antigens. Of these, 10 patients with persistent/refractory CMV infections or disease were eligible for treatment; a single infusion of cells produced 3 partial responses and 7 complete responses, for a cumulative response rate of 100% (95% confidence interval, 69.2-100) with no graft-versus-host disease, graft failure, or cytokine release syndrome. Potential wider use of the tested CMVSTs across transplant centers is made more feasible by our ability to produce sufficient material to generate cells for >2000 infusions from a single donor collection. Our data indicate that a "mini" bank of CMVSTs prepared from just 8 well-chosen third-party donors can supply the majority of patients with an appropriately matched line that produces safe and effective anti-CMV activity post-HSCT.

Optimal pre-emptive cytomegalovirus therapy threshold in a patient population with high prevalence of seropositive status

INTRODUCTION

Preemptive therapy (PET) for cytomegalovirus (CMV) reactivation post allogeneic hematopoietic stem cell transplantation (SCT) was shown to decrease the incidence of CMV disease. However, the optimal PET threshold is elusive.

PURPOSE OF THE STUDY

To examine the efficacy of PET initiation at a viral threshold of 1000 copies/mL (1560 IU/mL) in a patient population with high prevalence of CMV seropositive status.

PATIENTS AND METHODS

A single center retrospective review of patients that underwent allogeneic SCT was done.

RESULTS

A total of 195 allogeneic SCT recipients were included with median follow up of 18.1 (0.7-95.6) months. A total of 178 (91 %) of patients had a positive CMV PCR with median days to initial reactivation post SCT of 17 (1-1187); 129 patients had peak CMV titer < 1000 copies/mL (low titer) whereas the remaining 49 patients had a peak titer ≥ 1000 copies/mL (high titer). 120 (93 %) of patients with low titers cleared spontaneously with median time to clearance of 40 days (4-188). One patient in the high titer group developed CMV disease. At multivariable analysis; age at SCT HR 1.02 (1.004-1.04; 0.017), malignant vs. benign condition HR 9.4 (2.47-61; 0.0005) and cGVHD HR 0.37 (0.2-0.65; 0.0005) were significant for OS.

CONCLUSIONS

CMV reactivation post SCT was very common in patients with high prevalence of seropositive status. A PET threshold of 1000 copies/mL (1560 IU/mL) appears desirable as it was associated with spontaneous clearance in over 90 % of patients while minimizing treatment related toxicity. Validation of these observations is warranted.

Favorable Effect of Cytomegalovirus Reactivation on Outcomes in Cord Blood Transplant and Its Differences Among Disease Risk or Type

The effects of cytomegalovirus (CMV) reactivation on cord blood transplant (CBT) are unclear. We assessed the effect of CMV reactivation in adult single-unit CBT without in vivo T cell depletion. Of 3147 eligible cases, 2052 were acute myeloid leukemia (AML), 643 acute lymphoblastic leukemia (ALL), and 452 myelodysplastic syndrome (MDS). CMV reactivation up to 100 days after CBT was associated with better overall survival (OS) compared with no reactivation cases (57.3% versus 52.6% at 3 years after CBT), whereas nonrelapse mortality (NRM) was increased in ALL (16.2% versus 8.9%) and standard disease risk (17.1% versus 10.6%, P = .014) by CMV reactivation. On multivariate analysis, CMV reactivation had favorable effects on relapse in MDS (hazard ratio [HR], .55; P = .044) and high disease risk (HR, .77; P = .047). In NRM, only standard-risk cases showed adverse effects of CMV reactivation (HR, 1.56; P = .026). OS was significantly improved with CMV reactivation in a subgroup of patients with AML (HR, .84; P = .044), MDS (HR, .68; P = .048), and high disease risk (HR, .81; P = .013). This favorable effect of CMV reactivation on OS in AML and high disease risk cases was maintained even after considering the effect of grades II to IV acute graft-versus-host disease. Thus, CMV reactivation might have beneficial or adverse effects on relapse, NRM, and OS, depending on the disease type or disease risk.

Interferon-Responsive Genes Are Targeted during the Establishment of Human Cytomegalovirus Latency

Human cytomegalovirus (HCMV) latency is an active process which remodels the latently infected cell to optimize latent carriage and reactivation. This is achieved, in part, through the expression of viral genes, including the G-protein-coupled receptor US28. Here, we use an unbiased proteomic screen to assess changes in host proteins induced by US28, revealing that interferon-inducible genes are downregulated by US28. We validate that major histocompatibility complex (MHC) class II and two pyrin and HIN domain (PYHIN) proteins, myeloid cell nuclear differentiation antigen (MNDA) and IFI16, are downregulated during experimental latency in primary human CD14+ monocytes. We find that IFI16 is targeted rapidly during the establishment of latency in a US28-dependent manner but only in undifferentiated myeloid cells, a natural site of latent carriage. Finally, by overexpressing IFI16, we show that IFI16 can activate the viral major immediate early promoter and immediate early gene expression during latency via NF-κB, a function which explains why downregulation of IFI16 during latency is advantageous for the virus.IMPORTANCE Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus which infects 50 to 100% of humans worldwide. HCMV causes a lifelong subclinical infection in immunocompetent individuals but is a serious cause of mortality and morbidity in the immunocompromised and neonates. In particular, reactivation of HCMV in the transplant setting is a major cause of transplant failure and related disease. Therefore, a molecular understanding of HCMV latency and reactivation could provide insights into potential ways to target the latent viral reservoir in at-risk patient populations.

CMV Prevention and Treatment in Transplantation: What's New in 2019

PURPOSE OF REVIEW

Transplant recipients are at risk for cytomegalovirus (CMV) infection and associated morbidity and mortality. We summarize recently introduced or currently investigated modalities for prevention and treatment of CMV infection in hematopoietic cell (HCT) and solid organ transplant (SOT) recipients.

RECENT FINDINGS

Letermovir was recently approved for CMV prevention in HCT recipients. Data from real world studies support its role to improve outcomes in this population. Letermovir is currently under investigation for broader patient populations and indications. Maribavir is in late stages of development for CMV treatment and may provide a safer alternative to currently available anti-CMV drugs. Promising CMV vaccine candidates and adoptive cell therapy approaches are under evaluation. CMV immune monitoring assays are predicted to play a more central role in our clinical decision making. In recent years, major advances have been made in CMV prevention and treatment in transplant recipients. Rigorous research is ongoing and is anticipated to further impact our ability to improve outcomes in this population.

The Humoral Immune Response Against the gB Vaccine: Lessons Learnt from Protection in Solid Organ Transplantation

Human cytomegalovirus (hCMV) is considered to be the highest priority for vaccine development. This view is underscored by the significant morbidity associated with congenital hCMV infection and viraemia in transplant patients. Although a number of vaccines have been trialed, none have been licensed. The hCMV vaccine candidate that has performed best in clinical trials to date is the recombinant glycoprotein B (gB) vaccine that has demonstrated protection, ranging from a 43% to 50% efficacy in three independent phase II trials. In this review, we focus on data from the phase II trial performed in solid organ transplant patients and the outcomes of follow-up studies attempting to identify immunological and mechanistic correlates of protection associated with this vaccine strategy. We relate this to other vaccine studies of gB as well as other vaccine strategies to determine areas of commonality and divergence. Finally, through the review, we discuss the unique challenges and opportunities presented with vaccine studies in transplant populations with recommendations that could empower subsequent trials.

Antiviral prophylaxis for cytomegalovirus infection in allogeneic hematopoietic cell transplantation

Patients treated with allogeneic hematopoietic cell transplantation (HCT) are at risk of cytomegalovirus (CMV) reactivation and disease, which results in increased morbidity and mortality. Although universal antiviral prophylaxis against CMV improves outcomes in solid organ transplant recipients, data have been conflicting regarding such prophylaxis in patients undergoing allogeneic HCT. We conducted a systematic review of randomized trials of prophylactic antivirals against CMV after allogeneic HCT to summarize the evolution of the field over the last 35 years and evaluate the prophylactic potential of antiviral agents against CMV after allogeneic HCT. Electronic databases were queried from database inception through 31 December 2017. For included studies, incidence of CMV infection and all-cause mortality were collected as primary outcomes; CMV disease incidence, use of preemptive therapy, and drug toxicities were collected as secondary outcomes. Nineteen clinical trials conducted between 1981 and 2017 involving a total of 4173 patients were included for review. Prophylactic strategies included use of acyclovir, valacyclovir, ganciclovir, maribavir, brincidofovir, and letermovir compared with placebo or a comparator antiviral. Fourteen trials that compared antiviral prophylaxis with placebo demonstrated overall effectiveness in reducing incidence of CMV infection (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.42-0.58), CMV disease (OR, 0.56; 95% CI, 0.40-0.80), and use of preemptive therapy (OR, 0.51; 95% CI, 0.42-0.62; 6 trials); however, none demonstrated reduction in all-cause mortality (OR, 0.96; 95% CI, 0.78-1.18) except the phase 3 trial of letermovir (week-24 OR, 0.59; 95% CI, 0.38-0.98). Additional research is warranted to determine patient groups most likely to benefit from antiviral prophylaxis and its optimal deployment after allogeneic HCT.

Risk factors for cytomegalovirus disease in systemic lupus erythematosus (SLE): a systematic review

BACKGROUND

Cytomegalovirus (CMV) is an opportunistic pathogen causing reactivation and disease in Systemic Lupus Erythematosus (SLE) patients. This study aims to systematically review the literature for risk factors associated with CMV disease in SLE patients, in order to identify those more susceptible to CMV infection during their treatment.

METHODS

A systematic review was conducted on 4 different search engines and via hand search until May 2017. Studies were included after quality assessment via the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields (HTA KMET).

RESULTS

Two studies on CMV disease were included. Elevated CMV viral load, higher steroid doses, use of immunosuppressants and disease duration were the most commonly associated risk factors for CMV disease.

CONCLUSION

High CMV viral loads, longer SLE disease duration and higher steroid doses were associated with CMV disease. Further studies studying the risk of treatment drugs and role of interventions in the development of CMV infection are needed.

Evaluation of four commercial extraction-quantification systems to monitor EBV or CMV viral load in whole blood

BACKGROUND

Measurement of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) viral loads is commonly used to monitor posttransplant patients. Two new systems (eMAG/eSTREAM and Versant/kPCR) have been recently commercialized.

OBJECTIVES

To evaluate the performance of four systems to quantify CMV and EBV in whole blood.

STUDY DESIGN

Three extraction and real-time PCR amplification systems: m2000SP/RT (M2000), eMAG/eSTREAM (EMAG), and Versant/kPCR (KPCR) were compared with our routine system Qiasymphony/RGQ (QS/RGQ). The 4 systems were tested using 3 dilutions in triplicate according to the WHO international standard (WHO-IS) for intra-assay reproducibility; 56 whole blood samples (24 patients, 4 follow-ups) for CMV and 45 samples (27 patients, 3 follow-ups) for EBV.

RESULTS

For CMV, the mean of the WHO-IS (expected value: 4.7 Log IU/ml) was: QS/RGQ=4.84, M2000=4.61, EMAG=4.33, and KPCR=4.79. One patient (10 samples) presented a major underquantification by QS/RGQ. Of the 46 remaining samples, 41 were quantified with QS/RGQ, 43 with M2000, 33 with EMAG and 24 with KPCR. For EBV, the mean of the WHO-IS was: QS/RGQ=4.70, M2000=4.61, EMAG=4.62, and KPCR=4.57. Among the 45 samples, 43 were quantified with QS/RGQ, 39 with M2000, 40 with EMAG and 32 with KPCR.

CONCLUSION

The results obtained with the WHO-IS were very good. The results of patients' samples were well correlated with the announced sensitivity of each system. The elevated threshold of the KPCR CMV assay may be problematic for the follow-up of highly immunocompromised patients who require early introduction of treatment.

Cytomegalovirus disease in patients with hematopoietic stem cell transplantation, experience over 8 years

Objective

Cytomegalovirus infection and disease are significant causes of morbidity and mortality among patients with hematopoietic stem cell transplantation. The aim of this study was to assess the frequency of cytomegalovirus infection and characterize the patients who developed the disease.

Methods

A retrospective cohort study was performed among adult patients, recipients of allogeneic HSTC between 2008 and 2015. Taking into account the institutional protocol of prophylaxis infections in hematopoietic stem cell transplantation, patients received either preemptive therapy or prophylaxis with valganciclovir. Infection was defined as a positive pp65 antigenemia assay or PCR higher than 500 copies/mL. Disease was defined as viremia with evidence of end organ damage.

Results

Seventy patients were included, the median age was 36 years old (IQR 17–62). A total of 93% of the recipients had a positive serology. The Cytomegalovirus infection occurred in 59% of the patients. Eleven patients developed disease (16%), the most frequent manifestation being colitis, followed by pneumonitis and a single case of retinitis. There were no differences between the preemptive therapy or prophylaxis groups. The mean time of onset of the disease was day 94 post-transplant. Three patients developed disease with a viral load lower than 1000 copies/mL.

Conclusion

The incidence of cytomegalovirus infection after transplantation at our institution is high. It was found that the disease can occur with any level of viral load and is associated with high mortality.

Cytomegalovirus pneumonia in a patient with T-lymphoblastic leukemia/lymphoma after allogeneic hematopoietic stem cell transplantation: A case report

RATIONALE

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important treatment for hematological malignancies. Common complications are opportunistic infections and graft-versus-host disease (GVHD). Cytomegalovirus (CMV) is one of the most common causes of opportunistic infections.

PATIENT CONCERNS

A 30-year-old male was diagnosed with T-cell lymphoma after persistent cough and lymphadenopathy. Fever, abdominal pain, diarrhea, rash, and dyspnea occurred after HSCT.

DIAGNOSIS

The young man developed severe CMV infection with CMV detected in the bronchoalveolar lavage fluid and gastrointestinal tract.

INTERVENTIONS

Intravenous ganciclovir and high-dose glucocorticoids were administered after the patient was diagnosed with CMV pneumonia and enteritis.

OUTCOMES

After 3 weeks, the young man died from respiratory failure and infectious toxic shock caused by severe CMV infection.

LESSONS

Patients after HSCT should be closely monitored CMV-DNA in blood and other specimen, and treated first if necessary, so as to avoid the occurrence of severe infections such as CMV gastroenteritis and pneumonia.

Update on prevention of cytomegalovirus in hematopoietic cell transplantation

PURPOSE OF REVIEW

Cytomegalovirus infection (CMVi) has been the troll of allogeneic hematopoietic cell transplantation (allo-HCT). Over the last 4 decades various approaches have been adopted to minimize the burden from CMVi. There has been major advancement in the management of CMVi in HCT within the last few years that is poised to change the approaches employed in preventing and managing CMVi. This review will summarize recent advances and potential future development in the management of CMV in HCT.

RECENT FINDING

The major development has been the approval of letermovir for the prevention of CMVi in allo-HCT recipients. Also, with the potential availability of tests that can determine host CMV immunity a risk adapted approach to CMV prevention may become a possibility.

SUMMARY

The landscape of CMV prevention is about to change with the approval of a new anti-CMV antiviral that is safe and effective. However, the prophylaxis may lead to late onset CMVi in the context of ongoing risk factors after stopping prophylaxis and measures to counter this shifting epidemiology will need further research; such as extending the prophylaxis in high-risk patients vs. immunotherapy with vaccination and T-cell therapy.

A Native Human Monoclonal Antibody Targeting HCMV gB (AD-2 Site I)

Hyperimmune globulin (HIG) has shown efficacy against human cytomegalovirus (HCMV) for both transplant and congenital transmission indications. Replicating that activity with a monoclonal antibody (mAb) offers the potential for improved consistency in manufacturing, lower infusion volume, and improved pharmacokinetics, as well as reduced risk of off-target reactivity leading to toxicity. HCMV pathology is linked to its broad cell tropism. The glycoprotein B (gB) envelope protein is important for infections in all cell types. Within gB, the antigenic determinant (AD)-2 Site I is qualitatively more highly-conserved than any other region of the virus. TRL345, a high affinity (Kd = 50 pM) native human mAb to this site, has shown efficacy in neutralizing the infection of fibroblasts, endothelial and epithelial cells, as well as specialized placental cells including trophoblast progenitor cells. It has also been shown to block the infection of placental fragments grown ex vivo, and to reduce syncytial spread in fibroblasts in vitro. Manufacturing and toxicology preparation for filing an IND (investigational new drug) application with the US Food and Drug Administration (FDA) are expected to be completed in mid-2019.

Donor NKG2C Copy Number: An Independent Predictor for CMV Reactivation After Double Cord Blood Transplantation

Cytomegalovirus (CMV) remains a major cause of morbidity following allogeneic hematopoietic stem cell transplant. Natural killer cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. We studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood (CB) grafts (n = 200). In the setting of DUCBT, the combined graft may contain 0-4 functional copies of NKG2C gene. Sixteen patients received a combined graft with 1 or 2 NKG2C copies and 84 patients were recipients of a combined graft with 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 93.7 and 58.4%, respectively (p = 0.0003). In multivariate analysis, low NKG2C copies in the graft was an independent predictor of CMV reactivation (HR = 2.72, CI = 1.59-4.64; p < 0.0001). Our study points to an important role for donor NKG2C for protection against CMV reactivation after DUCBT. These novel findings may help identify patients at a higher risk of CMV reactivation after DUCBT. Donor NKG2C genotype may be used as a potential criterion in the algorithm for graft selection for DUCBT.

A fifty-year odyssey: prospects for a cytomegalovirus vaccine in transplant and congenital infection

INTRODUCTION

It has been almost fifty years since the Towne strain was used by Plotkin and collaborators as the first vaccine candidate for cytomegalovirus (CMV). While that approach showed partial efficacy, there have been a multitude of challenges to improve on the promise of a CMV vaccine. Efforts have been dichotomized into a therapeutic vaccine for patients with CMV-infected allografts, either stem cells or solid organ, and a prophylactic vaccine for congenital infection.

AREAS COVERED

This review will evaluate research prospects for a therapeutic vaccine for transplant recipients that recognizes CMV utilizing primarily T cell responses. Similarly, we will provide an extensive discussion on attempts to develop a vaccine to prevent the manifestations of congenital infection, based on eliciting a humoral anti-CMV protective response. The review will also describe newer developments that have upended the efforts toward such a vaccine through the discovery of a second pathway of CMV infection that utilizes an alternative receptor for entry using a series of antigens that have been determined to be important for prevention of infection.

EXPERT COMMENTARY

There is a concerted effort to unify separate therapeutic and prophylactic vaccine strategies into a single delivery agent that would be effective for both transplant-related and congenital infection.

Antiviral Therapies for Herpesviruses: Current Agents and New Directions

PURPOSE

The objective of this review was to summarize the recent literature describing the current burden of disease due to herpesviruses in the antiviral and transplant era; describe mechanisms of action of antiviral agents and the development of resistance; summarize the literature of recent antiviral agents brought to market as well as agents under development; and to present literature on future strategies for herpesvirus therapeutics.

METHODS

An extensive search of the medical literature related to antiherpesviral therapy was conducted to compose this narrative review. Literature searches were performed via PubMed and ultimately 137 articles were included as most relevant to the scope of this article.

FINDINGS

Herpesviruses are a family of DNA viruses that are ubiquitous throughout human populations and share the feature of establishing lifelong infections in a latent phase with the potential of periodic reactivation. With the exception of herpes simplex virus, varicella zoster virus, and Epstein-Barr virus, which have a significant disease burden in individuals with normal immune function, the morbidity and mortality of the remaining viruses are primarily associated with the immunocompromised host. Over the last half-century, several agents have been tested in large randomized, placebo-controlled trials that have resulted in safe and effective antiviral agents for the treatment of many of these infections.

IMPLICATIONS

With increasing use of antiherpesviral agents for extended periods, particularly in immunocompromised hosts, the emergence of resistant viruses has necessitated the development of newer agents with novel targets and better side-effect profiles.

Cytomegalovirus Serostatus Affects Autoreactive NK Cells and Outcomes of IL2-Based Immunotherapy in Acute Myeloid Leukemia

Human cytomegalovirus (CMV) infection is reported to promote NK cell differentiation and education. The CMV-induced generation of highly differentiated adaptive-like NK cells has been proposed to affect favorably on the maintenance of remission in patients with acute myeloid leukemia (AML) after allogeneic stem cell transplantation (allo-SCT). The impact of CMV infection and adaptive-like NK cells on relapse and survival of patients with AML not receiving allo-SCT remains unknown. We assayed CMV IgG serostatus to determine past CMV infection in 81 nontransplanted AML patients who were receiving relapse-prevention immunotherapy comprising histamine dihydrochloride and low-dose interleukin-2 (HDC/IL2; NCT01347996). CMV seropositivity correlated negatively with leukemia-free and overall survival of patients receiving HDC/IL2, but did not correlate with outcomes in a contemporary control cohort. Analysis of outcome after stratification of patients based on concordant or discordant killer immunoglobulin-like receptor (KIR) and HLA genotypes implied that the negative impact of CMV seropositivity was restricted to patients lacking a ligand to inhibitory KIRs (iKIR). Previous CMV infection was also associated with fewer NK cells expressing only nonself iKIRs (NS-iKIR). We propose that CMV-driven NK cell education depletes the population of NS-iKIR NK cells, which in turn reduces the clinical benefit of relapse-preventive immunotherapy in AML. Cancer Immunol Res; 6(9); 1110-9. ©2018 AACR.

Vaccination against the human cytomegalovirus

The human cytomegalovirus (HCMV) is the most important infectious cause of congenital abnormalities and also of infectious complications of transplantation. The biology of the infection is complex and acquired immunity does not always prevent reinfection. Nevertheless, vaccine development is far advanced, with numerous candidate vaccines being tested, both live and inactivated. This article summarizes the status of the candidate vaccines.

CMV immune evasion and manipulation of the immune system with aging

Human cytomegalovirus (HCMV) encodes numerous proteins and microRNAs that function to evade the immune response and allow the virus to replicate and disseminate in the face of a competent innate and acquired immune system. The establishment of a latent infection by CMV, which if completely quiescent at the level of viral gene expression would represent an ultimate in immune evasion strategies, is not sufficient for lifelong persistence and dissemination of the virus. CMV needs to reactivate and replicate in a lytic cycle of infection in order to disseminate further, which occurs in the face of a fully primed secondary immune response. Without reactivation, latency itself would be redundant for the virus. It is also becoming clear that latency is not a totally quiescent state, but is characterized by limited viral gene expression. Therefore, the virus also needs immune evasion strategies during latency. An effective immune response to CMV is required or viral replication will cause morbidity and ultimately mortality in the host. There is clearly a complex balance between virus immune evasion and host immune recognition over a lifetime. This poses the important question of whether long-term evasion or manipulation of the immune response driven by CMV is detrimental to health. In this meeting report, three groups used the murine model of CMV (MCMV) to examine if the contribution of the virus to immune senescence is set by the (i) initial viral inoculum, (ii) inflation of T cell responses, (iii) or the balance between functionally distinct effector CD4+ T cells. The work of other groups studying the CMV response in humans is discussed. Their work asks whether the ability to make immune responses to new antigens is compromised by (i) age and HCMV carriage, (ii) long-term exposure to HCMV giving rise to an overall immunosuppressive environment and increased levels of latent virus, or (iii) adapted virus mutants (used as potential vaccines) that have the capacity to elicit conventional and unconventional T cell responses.