Pre-emptive antiviral therapy for active CMV infection in adult allo-SCT patients guided by plasma CMV DNAemia quantitation using a real-time PCR assay: clinical experience at a single center

Epidemiology, clinical outcomes, and treatment patterns of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation in China: a scoping review and meta-analysis

Introduction

Cytomegalovirus (CMV) infection poses a significant threat to individuals undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), potentially resulting in substantial morbidity and mortality. This review summarized the epidemiology, clinical outcomes, and treatment patterns of CMV infection among allo-HSCT recipients in China.

Methods

PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang and Chinese Biomedical Literature Database (CBM) were systematically searched from 2013 to March 2023. All analyses were performed using R 4.1.1 software with a random effects model.

Results

Fifty-six studies, which included 13,882 patients, were reviewed. The pooled overall incidence of CMV infection was 49.99% [95% confidence interval (CI) 43.72-56.26%]. Among post allo-HSCT recipients with CMV infection, 32.03% (95% CI 22.93-41.12%) developed refractory CMV infection. The overall incidence of CMV disease was 13.30% (95% CI 8.99-19.66%). The pooled all-cause mortality rate was 29.25% (95% CI 17.96-40.55%) and the CMV-related mortality rate was 3.46% (95% CI 1.19-5.73%). Results demonstrate that management of CMV has mainly focused on pre-emptive therapy due to the treatment-limiting toxicity of anti-CMV agents. Additionally, CMV infection is continuing to occur after the discontinuation of prophylaxis, highlighting the unmet need for a more effective treatment without treatment-limiting toxicities.

Conclusion

This review underscores the urgent need for improved therapeutic strategies to effectively manage cytomegalovirus infection in allo-HSCT recipients, particularly in light of the high incidence and associated morbidity, as well as the limitations of current treatment options.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024513908, identifier: CRD42024513908.

Predicting cytomegalovirus infection and graft-versus-host disease using QuantiFERON-CMV and Monitor in pediatric transplants: a proof-of-concept study

Background

Cytomegalovirus (CMV) infection can lead to significant morbidity and mortality in pediatric hematopoietic stem cell transplant recipients. Early detection of CMV infection is crucial for managing its impact.

Aim

This study aims to evaluate the effectiveness of QuantiFERON-CMV® (QF-CMV) and QuantiFERON-Monitor® (QFM) tests in predicting CMV infection and graft-versus-host disease (GvHD) in pediatric hematopoietic stem cell transplant recipients to enhance patient outcomes and support personalized prevention strategies.

Methods

The QF-CMV and QFM tests were used to predict CMV pp65 antigen and GvHD in 24 pediatric hematopoietic stem cell transplant recipients.

Results

Data showed that positive CMV antigenemia (CMV-Ag) increased the risk of GvHD by 21.2%. QF-CMV and QFM were associated with CMV-Ag, with QF-CMV inversely predicting GvHD. Lymphocyte and neutrophil counts were positively linked to both tests.

Conclusion

The findings suggest that QF-CMV and QFM tests could predict GvHD and CMV infection risk and help identify high-risk patients, contributing to personalized prevention strategies and improving CMV treatment. Despite the small sample size, this study is an essential proof of concept due to the unique patient population of pediatric bone marrow stem cell transplant recipients. Further multicenter studies are needed to validate these results.

The Ten Most Common Questions on Cytomegalovirus Infection in Hematopoietic Stem Cell Transplant Patients

With the rising number of patients undergoing hematopoietic stem cell transplantation (HSCT), clinicians are more likely to encounter infectious complications in immunocompromised hosts, particularly cytomegalovirus (CMV) infection. Besides the high mortality of CMV end-organ disease, patients with detectable CMV viremia may have worse outcomes and decreased survival even in the absence of end-organ disease. In view of the implications on morbidity and mortality, clinicians should maintain a high index of suspicion and initiate antiviral drugs promptly when CMV infection is confirmed. High-risk patients should be identified in order to provide optimal management. Additionally, novel antiviral agents with a good safety profile and minor adverse events are now available for prophylaxis in high-risk patients and for treatment of resistant or refractory CMV infection. The following review provides concise, yet comprehensive, guidance on the burden and risk factors of CMV in this population, as well as an update on the latest evidence for the management of CMV infection.

Sirolimus versus cyclosporine in haploidentical stem cell transplantation with posttransplant cyclophosphamide and mycophenolate mofetil as graft-versus-host disease prophylaxis

Sirolimus has emerged as an alternative to calcineurin inhibitors-based (CNI) graft-versus-host disease (GVHD) prophylaxis. This retrospective study compares the outcome of 133 consecutive adult patients with haematological malignancies undergoing haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCy) and mycophenolate mofetil (MMF), combined with cyclosporine A (PTCy-CsA-MMF, n = 67) or sirolimus (PTCy-Sir-MMF, n = 66) as GVHD prophylaxis strategy. The median follow-up was 48 (range 22-83) and 13 (range 3-33) months, respectively. PTCy-CsA-MMF was associated in multivariate analyses with a higher risk of acute kidney injury (HR 2.1, 95% CI, 1.21-3.57, p = .008) and thrombotic microangiopathy (HR 12.5, 95% CI, 1.66-93.5, p = .014), whereas PTCy-Sir-MMF was associated with a higher risk of hepatic sinusoidal obstruction syndrome (SOS) (HR 10.8, 95% CI, 1.52-77, p = .018), especially late-onset forms, which totally resolved and none of the patients needed discontinuation of sirolimus. Two SOS-related deaths were detected, both in the PTCy-CsA-MMF subgroup. Both GVHD prophylaxis strategies were otherwise comparable in terms of engraftment, GVHD incidence and survival.

Features of Cytomegalovirus DNAemia Blips in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Implications for Optimization of Preemptive Antiviral Therapy Strategies

Cytomegalovirus (CMV) DNAemia occurs frequently in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). There is limited information about the incidence, features, and clinical impact of CMV DNAemia blips (episodes defined by an isolated positive PCR result) in this setting. In this retrospective study, 225 consecutive adult patients undergoing any modality of allo-HSCT at our center between May 2012 and July 2019 were included. Plasma CMV DNA load was monitored using a highly sensitive real-time PCR assay. In all, 187 of 225 patients had CMV DNAemia through day 365 after allo-HSCT (total number of episodes, n = 379). Eighty-three of the 187 patients had 1 or more blips (n = 104). Blips occurred as a first episode of CMV DNAemia as opposed to prolonged CMV DNAemia (≥2 consecutive positive PCR results) in 47 patients; in 20 of these patients, blips represented the only documented episode throughout the study period, and in 27 patients, blips preceded a prolonged CMV DNAemia episode. In the remaining 36 patients, blips developed as recurrences. Blips presenting as initial episodes occurred more frequently (P < .001) in patients receiving an allograft from a CMV-seropositive donor. The cumulative incidence of recurrent CMV DNAemia following initial blips, self-resolving prolonged CMV DNAemia episodes, or CMV DNAemia episodes treated preemptively with antivirals was not significantly different (P = .34). Receiver operating characteristic curve analysis indicated that a CMV DNA load cutoff of 48 IU/mL yielded the highest combined sensitivity (66%) and specificity (70.2%) for predicting a prolonged CMV DNAemia episode. The practical implications of our data in the optimization of preemptive antiviral therapy strategies are discussed.

Pulmonary cytomegalovirus (CMV) DNA shedding in allogeneic hematopoietic stem cell transplant recipients: Implications for the diagnosis of CMV pneumonia

OBJECTIVES

To date no definitive cut-off value for cytomegalovirus (CMV) DNA load in bronchoalveolar lavage (BAL) fluid specimens has been established to discriminate between CMV pneumonia and pulmonary CMV DNA shedding in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients.

METHODS

The current retrospective study is aimed at assessing the range of CMV DNA loads quantified in BAL fluid specimens from allo-HSCT patients with pneumonia in which different microorganisms were causally involved.

RESULTS

A total of 144 BAL specimens from 123 patients were included. CMV DNA was detected in 56 out of 144 BAL fluid specimens and the median CMV DNA load from patients in whom CMV pneumonia was unlikely or could be tentatively ruled out was 1210 (31-68, 920) IU/ml. The frequency of CMV DNA detection and median CMV DNA loads were comparable, irrespective of the attributable cause of pneumonia. Detection of CMV DNA loads in BAL fluid specimens >500 IU/ml was independently associated with pneumonia-attributable mortality.

CONCLUSIONS

The current study highlights the difficulty in establishing universal CMV DNA load thresholds in BAL fluid specimens for distinguishing between CMV pneumonia and pulmonary CMV DNA shedding, and suggests that the presence of CMV DNA in BAL fluid specimens beyond a certain level may have a deleterious impact on patient outcome.

Community-acquired respiratory virus lower respiratory tract disease in allogeneic stem cell transplantation recipient: Risk factors and mortality from pulmonary virus-bacterial mixed infections

Risk factors (RFs) and mortality data of community‐acquired respiratory virus (CARVs) lower respiratory tract disease (LRTD) with concurrent pulmonary co‐infections in the setting of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is scarce. From January 2011 to December 2017, we retrospectively compared the outcome of allo‐HSCT recipients diagnosed of CARVs LRTD mono‐infection (n = 52, group 1), to those with viral, bacterial, or fungal pulmonary CARVs LRTD co‐infections (n = 15, group 2; n = 20, group 3, and n = 11, group 4, respectively), and with those having bacterial pneumonia mono‐infection (n = 19, group 5). Overall survival (OS) at day 60 after bronchoalveolar lavage (BAL) was significantly higher in group 1, 2, and 4 compared to group 3 (77%, 67%, and 73% vs 35%, respectively, P = .012). Recipients of group 5 showed a trend to better OS compared to those of group 3 (62% vs 35%, P = .1). Multivariate analyses showed bacterial co‐infection as a RF for mortality (hazard ratio[HR] 2.65, 95% C.I. 1.2‐6.9, P = .017). We identified other 3 RFs for mortality: lymphocyte count <0.5 × 10⁹/L (HR 2.6, 95% 1.1‐6.2, P = .026), the occurrence of and CMV DNAemia requiring antiviral therapy (CMV‐DNAemia‐RAT) at the time of BAL (HR 2.32, 95% C.I. 1.1‐4.9, P = .03), and the need of oxygen support (HR 8.3, 95% C.I. 2.9‐35.3, P = .004). CARV LRTD co‐infections are frequent and may have a negative effect in the outcome, in particular in the context of bacterial co‐infections.

Impact of Cytomegalovirus Viral Load on Probability of Spontaneous Clearance and Response to Preemptive Therapy in Allogeneic Stem Cell Transplantation Recipients

The optimal viral load threshold at which to initiate preemptive cytomegalovirus (CMV) therapy in hematopoietic cell transplantation (HCT) recipients remains to be defined. In an effort to address this question, we conducted a retrospective study of 174 allogeneic HCT recipients who underwent transplantation at a single center between August 2012 and April 2016. During this period, preemptive therapy was initiated at the discretion of the treating clinician. A total of 109 patients (63%) developed CMV viremia. The median time to reactivation was 17 days (interquartile range, IQR, 7-30 days) post-HCT. A peak viremia ≥150 IU/mL was strongly associated with a reduced probability of spontaneous clearance (relative risk, .16; 95% confidence interval, .1-.27), independent of established clinical risk factors, including CMV donor serostatus, exposure to antithymocyte globulin, and underlying lymphoid malignancy. The median time to clearance of viremia was significantly shorter in those who started therapy at CMV <350 IU/mL (19 days; IQR, 11-35 days) compared with those who started antiviral therapy at higher viremia thresholds (33 days; IQR, 21-42 days; P = .02). The occurrence of treatment-associated cytopenias was frequent but similar in patients who started preemptive therapy at CMV <350 IU/mL and those who started at CMV >350 IU/mL (44% versus 57%; P = .42). Unresolved CMV viremia by treatment day 35 was associated with increased risk of therapeutic failure (32% versus 0%; P = .001). Achieving eradication of CMV viremia by treatment day 35 was associated with a 74% reduction in 1-year nonrelapse mortality (NRM) (adjusted hazard ratio [HR], .26; 95% confidence interval [CI], .1-.8; P = .02), whereas therapeutic failure was associated with a significant increase in the probability of 1-year NRM (adjusted HR, 26; 95% CI, 8-87; P <.0001). We conclude that among allogeneic HCT patients, a peak CMV viremia ≥150 IU/mL is associated with a >80% reduction in the probability of spontaneous clearance independent of ATG administration, CMV donor serostatus, and lymphoid malignancy, and is a reasonable cutoff for preemptive therapy. Delaying initiation of therapy until a CMV value ≥350 IU/mL is associated with more protracted CMV viremia, and unresolved viremia by treatment day 35 is associated with a significant increase in NRM.

The impact of virus population diversity on the dynamics of cytomegalovirus DNAemia in allogeneic stem cell transplant recipients

Mixed cytomegalovirus (CMV) infections are associated with delayed viral clearance in solid organ transplant recipients. We investigated whether this could be extrapolated to allogeneic stem cell transplant (allo-SCT) recipients. A total of 48 plasma specimens, obtained during 29 episodes of active CMV infection in 25 non-consecutive allo-SCT patients, were analysed. Baseline blood specimens, drawn shortly prior to the inception of pre-emptive antiviral therapy (pre-treatment specimen; n=29), as well as follow-up samples obtained either after the initiation of antiviral therapy (post-treatment specimen; n=15) or during recurrent episodes (n=4) were analysed. Plasma CMV DNA loads were quantified by real-time PCR and the CMV genotyping was performed by ultra-deep sequencing of hypervariable regions in the genes coding for glycoproteins N (gN) and O (gO). A trend towards higher CMV DNA peak loads, longer CMV DNAemia episode durations and slower CMV DNAemia decay rates was observed for episodes with mixed CMV genotype populations compared to those caused by single CMV variants, although the differences did not reach statistical significance. The length of the treatment course required to clear DNAemia was significantly longer in these mixed episodes (P=0.002). Significant changes in the number or frequency of CMV gN or gO genetic variants were documented following the initiation of antiviral therapy or in recurrent episodes. CMV diversity may have a major impact on the kinetics of CMV DNAemia clearance during the treatment of active CMV infection episodes in allo-SCT recipients.

Emerging concepts in cytomegalovirus infection following hematopoietic stem cell transplantation

Despite the refinements in molecular methods for the detection of cytomegalovirus (CMV) and the advent of highly effective preemptive strategies, CMV remains a leading cause of morbidity and mortality in hematopoietic cell transplant (HCT) recipients. CMV can cause tissue-invasive disease including pneumonia, hepatitis, colitis, retinitis, and encephalitis. Mortality in HCT recipients with CMV disease can be as high as 60%. CMV infection has been associated with increased risk of secondary bacterial and fungal infections, increased risk of graft-versus-host disease, and high rates of non-relapse mortality following HCT. The risk of CMV is highly dependent on the donor (D) and the recipient (R) serostatus (D^-/R⁺>D⁺/R⁺>D⁺/R^->D^-/R^-). Among allogeneic HCT recipients, high-dose corticosteroids, T-cell depletion, graft-versus-host disease, and mismatched or unrelated donors constitute the main predisposing factors. However, not all seropositive individuals with these risk factors develop CMV, which strongly suggests that host factors, such as those regulating CMV-specific T-cell responses, play a major role in predisposition to CMV in HCT recipients. Here, we discuss emerging concepts in CMV infection in HCT with emphasis on immunological factors that govern CMV reactivation and the applicability of immune monitoring to understand correlates of pathogenesis and its potential to guide clinical decision making.

CMV in Hematopoietic Stem Cell Transplantation

Due to its negative impact on the outcome of stem cell transplant (SCT) and solid organ transplant patients (SOT) CMV has been called “the troll of transplantation”. One of the greatest advances in the management of SCT has been the introduction of the preemptive strategy. Since its introduction, the incidence of the viremia, as expected, remains unchanged but there has been a marked decline in the incidence of early CMV disease. However, in spite of the advances in prevention of CMV disease, CMV is still today an important cause of morbidity and mortality. Late CMV disease is still occurring in a significant proportion of patients and the so-called indirect effects of CMV are causing significant morbidity and mortality. Fortunately there have been several advances in the development of new antivirals, adoptive immunotherapy and DNA-CMV vaccines that might transform the management of CMV in the near future.

Efficacy and Safety of a Preemptive Antiviral Therapy Strategy Based on Combined Virological and Immunological Monitoring for Active Cytomegalovirus Infection in Allogeneic Stem Cell Transplant Recipients

Preemptive antiviral therapy for active CMV infection in allogeneic stem cell transplant recipients guided by immunological and virological parameters minimizes the risk of recurrent viremia in a subset of patients.

Background. Preemptive antiviral therapy for active cytomegalovirus (CMV) infection in allogeneic stem cell transplant recipients (Allo-SCT) results in overtreatment and a high rate of recurrences. Monitoring of CMV-specific T-cell immunity may help to individualize treatments and minimize these problems.

Methods. We conducted a prospective, multicenter, matched comparison-group study to evaluate the efficacy and safety of a novel strategy that consisted of interrupting anti-CMV therapy upon CMV DNAemia clearance and concurrent detection of phosphoprotein 65/immediate-early-1-specific interferon-γ-producing CD8⁺ T cells at levels of >1 cell/µL (within 30 days after the initiation of therapy). Immunological monitoring was performed on days +7, +14, +21, and +28 after treatment initiation. The primary endpoint was the cumulative incidence of recurrent DNAemia within 2 months after treatment cessation. Secondary endpoints were the length of antiviral treatment courses and the incidence of hematological toxicity.

Results. Sixty-one patients were enrolled in the study group. Fifty-six patients were included in the matched-control group. Eleven patients (18%) fulfilled the criteria for antiviral treatment interruption. The cumulative incidence of recurrent CMV DNAemia was significantly lower (P = .02) in these patients than in patients in the comparative groups. Likewise, the length of antiviral treatment courses was significantly shorter in these patients than that in patients in the matched-control group (P = .003). No significant differences in the incidence of hematological toxicity was observed between the comparative groups.

Conclusions. Our data support the clinical utility of combining immunological and virological monitoring for the management of CMV infection in a subset of Allo-SCT recipients.

An update on the management and prevention of cytomegalovirus infection following allogeneic hematopoietic stem cell transplantation

ABSTRACT 

A significant progress has been made in deciphering critical aspects of the biology and immunology of CMV infection in the allogeneic stem cell transplantation setting. Genetic traits predisposing to active CMV infection and CMV end-organ disease have begun to be delineated. Reliable molecular assays for CMV DNA load quantitation in body fluids have been developed. Elucidation of immune mechanisms affording control of CMV infection will help to improve the management of active CMV infection. Finally, the advent of new CMV-specific antivirals and promising vaccine prototypes as well as the development of fine procedures for large-scale ex vivo generation of functional CMV-specific T cells for adoptive T cell transfer therapies will certainly minimize the negative impact of CMV on survival in these patients.

Early kinetics of plasma cytomegalovirus DNA load in allogeneic stem cell transplant recipients in the era of highly sensitive real-time PCR assays: does it have any clinical value?

We report that in a population of allogeneic stem cell transplant recipients, determination of the viral doubling time (dt) of the cytomegalovirus (CMV) DNA plasma load predicted the eventual need for inception of preemptive antiviral therapy, whereas the level of the initial plasma CMV DNA load did not. The data thus indicated that determination of the dt of CMV DNA may be useful in the therapeutic management of CMV infection in this clinical setting.