CMV viral load kinetics predict CMV end-organ disease and mortality after hematopoietic cell transplant (HCT)

Comparison of valganciclovir versus foscarnet for the treatment of cytomegalovirus viremia in adult acute leukemia patients after allogeneic hematopoietic cell transplantation

Cytomegalovirus (CMV) reactivation increases treatment-related mortality (TRM) after allogeneic hematopoietic cell transplantation (allo-HCT). We analyzed 141 adult acute leukemia (AL) patients suffered allo-HCT between 2017 and 2021, who developed CMV viremia post-HCT and treated with valganciclovir or foscarnet, to evaluate effectiveness and safety of both drugs. Viremia clearance rates (14 and 21 d post treatment) and toxicities were similar in two groups. However, valganciclovir was associated with a lower cumulative incidence of CMV recurrence within 180 days (16.7% vs. 35.7%, p=0.029) post CMV clearance. Finally, 2-year TRM was lower in valganciclovir group (9.7% ± 0.2% vs. 26.2% ± 0.3%, p = 0.026), result a superior 2-year overall survival (OS; 88.1% ± 5.2% vs. 64.4% ± 5.5%, p = 0.005) and leukemia-free survival (LFS; 82.0% ± 5.9% vs. 58.9% ± 5.6%, p = 0.009). Valganciclovir might decrease CMV viremia recurrence and led to better long-term outcome than foscarnet in adult AL patients developed CMV viremia post-HCT. Considering the inherent biases of retrospective study, well-designed trials are warranted to validate our conclusion.

Viral load kinetics and the clinical consequences of cytomegalovirus in kidney transplantation

Background

Despite advances in clinical management, cytomegalovirus (CMV) infection remains a serious complication and an important cause of morbidity and mortality following kidney transplantation. Here, we explore the importance of viral load kinetics as predictors of risk and potential guides to therapy to reduce transplant failure in a large longitudinal Genome Canada Transplant Consortium (GCTC) kidney transplant cohort.

Methods

We examined the relationship between CMV infection rates and clinical characteristics, CMV viral load kinetics, and graft and patient outcomes in 2510 sequential kidney transplant recipients in the British Columbia Transplant Program. Transplants were performed between January 1, 2008, and December 31, 2018, were managed according to a standard protocol, and were followed until December 31, 2019, representing over 3.4 million days of care.

Results

Longitudinal CMV testing was performed in 2464 patients, of whom 434 (17.6%) developed a first episode of CMV viremia at a median of 120 (range: 9-3906) days post-transplant. Of these patients, 93 (21.4%) had CMV viremia only and 341 (78.6%) had CMV viremia with clinical complications, of whom 21 (4.8%) had resulting hospitalization. A total of 279 (11.3%) patients died and 177 (7.2%) patients lost their graft during the 12 years of follow-up. Patients with CMV infection were at significantly greater risk of graft loss (p=0.0041) and death (p=0.0056) than those without. Peak viral load ranged from 2.9 to 7.0 (median: 3.5) log10 IU/mL, the duration of viremia from 2 to 100 (15) days, and the viral load area under the curve from 9.4 to 579.8 (59.7) log10 IU/mL × days. All three parameters were closely inter-related and were significantly increased in patients with more severe clinical disease or with graft loss (p=0.001). Duration of the first CMV viremic episode greater than 15 days or a peak viral load ≥4.0 log10 IU/mL offered simple predictors of clinical risk with a 3-fold risk of transplant failure.

Conclusion

Viral load kinetics are closely related to CMV severity and to graft loss following kidney transplantation and provide a simple index of risk which may be valuable in guiding trials and treatment to prevent transplant failure.

Epstein-Barr virus reactivation correlates with worse outcomes for patients exposed to hepatitis B virus after haploidentical hematopoietic stem cell transplantation

Hepatitis B virus (HBV)has a high, chronic infection rate in Asian populations, but only few studies have analyzed the effect of Epstein-Barr virus (EBV) or Cytomegalovirus (CMV) reactivation in patients exposed to HBV after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). This study aimed to assess the clinical outcomes of these patients. We conducted a retrospective research including 61 patients exposed to HBV after undergoing haplo-HSCT. The patients were classified into two groups: the CMV reactivation group and no CMV reactivation group. The results were compared between the two groups using the K-W test for continuous variables, Pearson's chi-square test for categorical variables, Kaplan-Meier curves to estimate overall survival (OS) and leukemia-free survival (LFS), and a Cox proportional hazards model to analyze multivariable influences. The 3-year cumulative HBV reactivation rate was 8.2%. The median duration of HBV reactivation was 16 months (16-22 months) after haplo-HSCT. The CMV reactivation group had a higher cumulative incidence of HBV reactivation than the group without CMV reactivation. The EBV reactivation was substantially higher in the CMV reactivation group compared to that in the no CMV reactivation group (37.0% vs.5.9% respectively; P = 0.002). Furthermore, EBV reactivation was a risk factor for 1-year LFS and 1-year OS. Based on our data, EBV reactivation was related to worse outcomes in patients exposed to HBV after haplo-HSCT, whereas CMV reactivation was not.

How I prevent viral reactivation in high-risk patients

Preventing viral infections at an early stage is a key strategy for successfully improving transplant outcomes. Preemptive therapy and prophylaxis with antiviral agents have been successfully used to prevent clinically significant viral infections in hematopoietic cell transplant recipients. Major progress has been made over the past decades in preventing viral infections through a better understanding of the biology and risk factors, as well as the introduction of novel antiviral agents and advances in immunotherapy. High-quality evidence exists for the effective prevention of herpes simplex virus, varicella-zoster virus, and cytomegalovirus infection and disease. Few data are available on the effective prevention of human herpesvirus 6, Epstein-Barr virus, adenovirus, and BK virus infections. To highlight the spectrum of clinical practice, here we review high-risk situations that we handle with a high degree of uniformity and cases that feature differences in approaches, reflecting distinct hematopoietic cell transplant practices, such as ex vivo T-cell depletion.

Viral infection in hematopoietic stem cell transplantation: an International Society for Cell & Gene Therapy Stem Cell Engineering Committee review on the role of cellular therapy in prevention and treatment

Despite recent advances in the field of HSCT, viral infections remain a frequent causeof morbidity and mortality among HSCT recipients. Adoptive transfer of viral specific T cells has been successfully used both as prophylaxis and treatment of viral infections in immunocompromised HSCT recipients. Increasingly, precise risk stratification of HSCT recipients with infectious complications should incorporate not only pretransplant clinical criteria, but milestones of immune reconstitution as well. These factors can better identify those at highest risk of morbidity and mortality and identify a population of HSCT recipients in whom adoptive therapy with viral specific T cells should be considered for either prophylaxis or second line treatment early after inadequate response to first line antiviral therapy. Broadening these approaches to improve outcomes for transplant recipients in countries with limited resources is a major challenge. While the principles of risk stratification can be applied, early detection of viral reactivation as well as treatment is challenging in regions where commercial PCR assays and antiviral agents are not readily available.

Time to initiation of pre-emptive therapy for cytomegalovirus impacts overall survival in pediatric hematopoietic stem cell transplant recipients

BACKGROUND AIMS

Cytomegalovirus (CMV) reactivation is a significant complication following allogeneic hematopoietic stem cell transplant (HSCT) and affects upwards of 40% of pediatric HSCT patients. Pre-emptive therapy remains the only effective treatment strategy available for pediatric patients following CMV reactivation. Little is known about how the timing of induction treatment following CMV reactivation impacts outcomes in pediatric patients, especially following ex vivo T-cell-depleted (TCD) HSCT.

METHODS

The authors evaluated how the timing of induction treatment after CMV reactivation impacts overall survival (OS) and CMV disease in pediatric patients undergoing TCD HSCT at a single institution. The authors retrospectively analyzed patients treated on the pediatric service who received an initial ex vivo TCD HSCT at Memorial Sloan Kettering Cancer Center (MSKCC) from January 2010 to June 2018. CMV reactivation was defined as ≥1 CMV polymerase chain reaction >500 copies/mL in whole blood or >137 IU/mL in plasma within the first 180 days after allogeneic HSCT. To analyze the impact of the timing of induction treatment, the authors' primary study outcome was OS and secondary outcome was CMV disease.

RESULTS

A total of 169 patients who underwent an initial allogeneic TCD HSCT on the pediatric service at MSKCC from January 2010 to June 2018 were included in the analysis. Thirty-seven (22%) patients reactivated CMV during the first 180 days following HSCT. Of those patients who reactivated CMV, CMV donor/recipient (D/R) serostatus was as follows: D+/R+ n = 28 (76%) and D-/R+ n = 9 (24%). There was no CMV reactivation observed among recipients who were CMV-seronegative irrespective of donor serostatus. In those patients who reactivated CMV, the median time from HSCT to CMV reactivation was 24 days (interquartile range, 20-31). Eleven patients ultimately developed CMV disease in addition to CMV viremia, whereas the remaining patients had only CMV viremia. The cumulative incidence of CMV reactivation at 60 days was 45.2% (95% confidence interval [CI], 32.8-57.5) in the D+/R+ subgroup and 31% (95% CI, 14.2-47.9) in the D-/R+ subgroup. For those patients who reactivated CMV, 30 (81%) received induction treatment with ganciclovir or foscarnet. To analyze the impact of the timing of induction treatment on clinical outcomes, the authors restricted the analysis to those patients who reactivated CMV and received induction treatment (n = 30). The timing of induction treatment was significantly associated with OS, with optimal timing of initiation within a week of CMV reactivation (P = 0.02). There was no significant impact on the timing of induction treatment and risk of CMV disease (P = 0.30).

CONCLUSIONS

In ex vivo TCD HSCT in pediatric patients, early initiation of induction treatment after CMV reactivation is associated with improved OS.

Association Between Cytomegalovirus and Epstein-Barr Virus Co-Reactivation and Hematopoietic Stem Cell Transplantation

The co-reactivation of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in patients undergoing hematopoietic stem cell transplantation (HSCT) has been found. Research has shown that the reactivation of CMV or EBV is closely related to poor HSCT outcomes. In this study, we describe the clinical characteristics of HSCT patients with co-reactivation of CMV and EBV. We retrospectively reviewed the medical records of 327 patients who underwent HSCT at the Peking University People’s Hospital Institute of Hematology. Co-reactivation of CMV and EBV was observed in a total of 75 patients (22.9%) who also had a higher incidence of hemorrhagic cystitis (P=0.000). HSCT patients with CMV and co-reactivation of CMV and EBV had a significantly lower 1-year overall survival (OS; P=0.050). Further, COX regression analysis showed that viral infection was a risk factor for 1-year OS (HR, 12.625 for co-reactivation vs. no reactivation, p=0.021, and HR 13.580 for CMV reactivation vs. no reactivation, P=0.013). In conclusion, the patients with CMV reactivation had poorer outcome after HSCT regardless of EBV reactivation.

Use of a sample-to-result shotgun metagenomics platform for the detection and quantification of viral pathogens in paediatric immunocompromised patients

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The Galileo Viral Panel metagenomic sequencing platform was compared to singleplex qPCR for the detection and quantification of DNA viruses in immunocompromised paediatric patients.

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Galileo had high qualitative and quantitative agreement with qPCR.

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Galileo was able to detect additional viruses not targeted in routine testing.

Background

Infections by several DNA viruses can severely impact outcomes in paediatric immunocompromised patients. Current testing, which is generally limited to singleplex qPCR assays, can miss both common and rarer viruses if they are not targeted.

Objectives

To evaluate the performance of the Galileo Viral Panel (Galileo), a sample-to-result shotgun metagenomics platform for the detection and quantification of 12 DNA viruses, compared to standard of care qPCR assays.

Study design

A clinical performance evaluation was carried out using 43 prospectively collected EDTA plasma samples positive for one or more DNA viruses. Agreement between assays was assessed by overall, positive, and negative percent agreement, as well as quantitative agreement by linear regression and Bland-Altman analysis.

Results

Overall positive percent agreement was 84% (95% CI: 76%-90%), and negative percent agreement was 95% (95% CI: 92%-97%). There was a high correlation between Galileo and qPCR for ADV, CMV, EBV, and VZV (R² = 0.91) and a mean difference by Bland Altman of -0.43 log₁₀ IU or cp/ml (95% limits of agreement, -1.37 to 0.51). In addition, there was a high correlation between Galileo Signal Score and qPCR for TTV (R² = 0.85).

Conclusion

We observed high qualitative and quantitative agreement between qPCR and Galileo. Galileo identified additional viruses that were not tested with routine qPCR and could impact clinical outcomes.

Impact of Letermovir Primary Cytomegalovirus Prophylaxis on 1-Year Mortality After Allogeneic Hematopoietic Cell Transplantation: A Retrospective Cohort Study

BACKGROUND

Cytomegalovirus (CMV)-seropositive (R+) hematopoietic cell transplant (HCT) recipients have a survival disparity compared with CMV-seronegative recipient/donor (R-D-) pairs. We hypothesized that primary letermovir prophylaxis (LET) may abrogate this disparity. We investigated the relationship between LET and mortality at 1 year post-HCT.

METHODS

In this retrospective cohort study, we included adult R-D- or R+ patients who received HCT pre-LET (between 1 January 2013 through 15 December 2017) and post-LET (between 16 December 2017 through December 2019). R+ were categorized by LET receipt as R+/LET or R+/no-LET. Cox proportional hazard models were used to estimate the association of LET with all-cause mortality at 1 year after transplantation.

RESULTS

Of 848 patients analyzed, 305 were R-D-, 364 R+/no-LET, and 160 R+/LET. Because of similar mortality (adjusted hazard ratio [aHR], 1.29 [95% confidence interval {CI}, .76-2.18]; P = .353]) between pre-LET/R-D- and post-LET/R-D-, R-D- were combined into 1 group. Compared with R-D-, the aHR for mortality was 1.40 (95% CI, 1.01-1.93) for R+/no-LET and 0.89 (95% CI, .57-1.41) for R+/LET. Among R+, LET was associated with decreased risk of death (aHR, 0.62 [95% CI, .40-.98]); when conventional HCT and T-cell depleted HCT were analyzed separately, the aHR was 0.86 (95% CI, .51-1.43) and 0.21 (95% CI, .07-.65), respectively.

CONCLUSIONS

At 1 year post-HCT, LET was associated with closing the mortality disparity between R-D- and R+. Among all R+, LET was associated with decreased mortality, driven by 79% reduced incidence of death in T-cell depleted HCT.

Combined Analysis of Early CD4+ T Cell Counts and CMV Serostatus May Improve CMV Risk Assessment after Allogeneic Hematopoietic Cell Transplantation

The incidence and severity of viral complications after cellular therapy are highly variable. Recent publications describe relevant interactions between the human Cytomegalovirus (CMV) and host immunity in recipients of allogeneic hematopoietic cell transplantation (HCT). Although immune monitoring is routinely performed in HCT patients, validated cut-off levels correlating with transplant outcomes such as survival or CMV reactivation are mostly limited to day +100, which is later than the median time for CMV reactivation in the absence of medical prophylaxis. To address this gap in early risk assessment, we applied an unsupervised machine learning technique based on clustering of day +30 CD4⁺ helper T cell count data, and identified relevant cut-off levels within the diverse spectrum of early CD4⁺ reconstitution. These clusters were stratified for CMV recipient serostatus to identify early risk groups that predict clinical HCT outcome. Indeed, the new risk groups predicted subsequent clinical events such as NRM, OS, and high CMV peak titers better than the most established predictor, i.e., the positive CMV recipient serostatus (R+). More specifically, patients from the R+/low CD4⁺ subgroup strongly associated with high CMV peak titers and increased 3-year NRM (subdistribution hazard ratio (SHR) 10.1, 95% CI 1.38–73.8, p = 0.023), while patients from the R-/very high CD4⁺ subgroup showed comparable NRM risks (SHR 9.57, 95% CI 1.12–81.9, p = 0.039) without such an association. In short, our study established novel cut-off levels for early CD4⁺ T cells via unsupervised learning and supports the integration of host cellular immunity into clinical risk-assessment after HCT in the context of CMV reactivation.