Cytomegalovirus infection in patients who underwent allogeneic hematopoietic stem cell transplantation in Portugal: a five-year retrospective review

Impact of Primary Letermovir Prophylaxis Versus Preemptive Antiviral Therapy for Cytomegalovirus on Economic and Clinical Outcomes after Hematopoietic Cell Transplantation

Preemptive therapy (PET) historically has been the primary strategy to reduce early-onset cytomegalovirus (CMV) reactivation after allogeneic hematopoietic cell transplantation (HCT) but is associated with antiviral-associated toxicities and increases in healthcare resource utilization and cost. Despite its high cost, letermovir (LTV) prophylaxis has largely supplanted PET due to its effectiveness and tolerability. Direct comparisons between LTV and PET approaches on economic and clinical outcomes after allogeneic HCT remain limited. Objective: To compare total cost of care (inpatient and outpatient) between LTV prophylaxis and PET through day+180 after allogeneic HCT. Adult allogeneic CMV seropositive (R+) HCT recipients who initiated LTV <30 days after HCT between 01/01/18 and 12/31/18 were matched 1:1 to allogeneic CMV R+ HCT recipients between 01/01/15 and 12/31/17 (PET cohort). Patients were grouped into high-risk (HR) or standard-risk (SR) for CMV to compare the LTV and PET cohorts. Direct costs for each patient's index HCT admission and all subsequent inpatient and outpatient care through day+180 after HCT were determined and converted into 2021 US dollars and then to Medicare proportional dollars (MPD). A secondary analysis using 2019 average wholesale price was conducted to specifically evaluate anti-CMV medication costs. There were a total of 176 patients with 54 HR CMV pairs and 34 SR CMV pairs. No differences in survival between LTV and PET for both HR and SR CMV groups were observed. The rate of clinically significant CMV infection decreased for both HR CMV (11/54, 20.4% versus 38/54, 70.4%, P < .001) and SR CMV (1/34, 2.9% versus 12/34, 35.3%, P < .001) patients who were given LTV prophylaxis with corresponding reductions in val(ganciclovir) and foscarnet (HR CMV only) use. Among HR CMV patients, LTV prophylaxis was associated with reductions in CMV-related readmissions (3/54, 5.6% versus 18/54, 33.3%, P < .001) and outpatient visits within the first 100 days after HCT (20 versus 25, P = .002), and a decreased median total cost of care ($36,018 versus $75,525, P < .001) in MPD was observed. For SR CMV patients on LTV, a significant reduction in the median inpatient cost ($15,668 versus $27,818, P < .001) was found, but this finding was offset by a higher median outpatient cost ($26,145 versus $20,307, P = .030) that was not CMV-driven. LTV prophylaxis is highly effective in reducing clinically significant CMV reactivations for both HR and SR HCT recipients. In this study, LTV prophylaxis was associated with a decreased total cost of care for HR CMV patients through day+180. Specifically, reductions in CMV-related readmissions, exposure to CMV-directed antiviral agents, and outpatient visits in the first 100 days after HCT were observed. SR CMV patients receiving LTV prophylaxis benefited by having a reduced inpatient cost of care due to lowered room and pharmacy costs.

[Management of Cytomegalovirus Infection in Allogeneic Hematopoietic Stem Cell Transplant Recipients]

Cytomegalovirus (CMV) is a type of double-stranded deoxyribonucleic acid virus belonging to the herpesviridae family. Following a primary infection, the virus becomes latent in various types of white blood cells. Cytomegalovirus infection can remain latent or become active, especially in immunocompromised individuals, such as those undergoing hematopoietic stem cell transplantation (HSCT), where CMV reactivation can occur. In this context, CMV infection is common and associated with high rates of morbidity and mortality. Pneumonia is one of the most serious complications, with mortality rates exceeding 50%. Additionally, even in the absence of organ-specific disease, CMV infection is related to increased mortality unrelated to hematologic neoplasm recurrence. Given the frequency and severity of this infection in HSCT patients, it is crucial to implement effective strategies for monitoring, prevention, and treatment. This guideline was developed to identify patient groups that benefit from a systematic approach to CMV infection and to define the most appropriate strategy for each group. Monitoring CMV viral load in peripheral blood is crucial, especially in patients at moderate to high risk of active infection. Primary prophylaxis with letermovir (an antiviral drug) is recommended to reduce the incidence of active infection, especially in high-risk patients. Secondary prophylaxis with valganciclovir (antiviral drug) is recommended after an episode of active infection, while preemptive and disease treatment is based on monitoring viral load and clinical response. The aim of this guideline is to improve the approach to CMV infection in HSCT patients, ensuring an effective and safe preventive and therapeutic approach.

Impact of cytomegalovirus (CMV) seroconversion pre-allogeneic hematopoietic cell transplantation on posttransplant outcomes

Cytomegalovirus (CMV) reactivation post-allogeneic hematopoietic cell transplantation (post-alloHCT) increases morbidity and mortality. We sought to determine the frequency of CMV seroconversion in patients pre-alloHCT and to investigate the impact on posttransplant outcomes. We retrospectively investigated 752 adult patients who underwent alloHCT at our center from January 2015 to February 2020 before the adoption of letermovir prophylaxis. CMV serology was assessed at consult and pretransplant. The cohort was divided into four groups based on pretransplant CMV seroconversion: negative to positive (Group 1), positive to negative (Group 2), consistently negative (Group 3), and consistently positive (Group 4). Eighty-nine patients (12%) had seroconverted from negative to positive, 17 (2%) from positive to negative, 151 (20%) were consistently seronegative, and 495 (66%) were consistently seropositive pretransplant. For the four CMV serostatus groups, cumulative incidence of CMV reactivation at 6 months posttransplant was 4.5%, 47.1%, 6.6%, and 76.6% for Groups 1, 2, 3, and 4, respectively (p < .0001). No differences between groups were seen regarding Grade III-IV acute graft-versus-host disease (GVHD) (p = .91), moderate/severe chronic GVHD (p = .41), or graft failure (p = .28). On multivariable analysis, there was no impact of CMV serostatus group on overall survival (p = .67), cumulative incidence of relapse (p = .83) or non-relapse mortality. alloHCT patients who demonstrate CMV seroconversion pretransplant from negative to positive have a very low risk of CMV reactivation posttransplant. The observed seroconversion may be due to passive CMV immunity acquired through blood products. Quantitative CMV immunoglobulin G/immunoglobulin M pretransplant may help differentiate between true seroconversion and passively transmitted CMV immunoglobulin.

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.

The indirect effects of CMV reactivation on patients following allogeneic hematopoietic stem cell transplantation: an evidence mapping

Cytomegalovirus (CMV) reactivation following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a challenging problem, and the impact on the risk of overall mortality (OM) and non-relapse mortality (NRM) in patients following allo-HSCT is still controversial. Utilizing the evidence mapping method, we aimed to assess the effect of CMV infection on outcomes of patients post-transplantation and identify research gaps through systematic reviews (SRs) and clinical studies. PubMed, EMBASE, Web of Science, and Cochrane library databases were searched from inception until 5 July 2022 to identify relevant literature. After systematic literature screening and data extraction, evidence mapping of the effects of CMV reactivation on patients post-allo-HSCT was conducted. Three SRs and 22 clinical studies were included. In one SR, CMV reactivation was associated with an increased risk of mortality (HR 1.46; 95% CI, 1.24-1.72; P ≤ 0.001). In two SRs, CMV reactivation was associated with NRM. One SR reported CMV reactivation was potentially associated with significant protection against relapse in patients with acute myelocytic leukemia (AML), but no significant correlation with graft-versus-host disease (GVHD) was found. Lastly, in one SR CMV reactivation significantly increased the risk of invasive fungal disease (IFD). Most clinical articles reported that CMV reactivation increased the risk of renal dysfunction, poor graft function, re-hospitalization, and bacterial infections. CMV reactivation following allo-HSCT is associated with an increased risk of OM, NRM, IFD, and renal dysfunction, as well as a reduced risk of relapse in patients with AML.

Letermovir prophylaxis for cytomegalovirus reactivation in allogeneic hematopoietic cell transplant recipients: Single center Canadian data

BACKGROUND

Cytomegalovirus (CMV) is associated with morbidity and mortality following allogeneic hematopoietic cell transplantation (alloHCT). Letermovir is a novel antiviral agent that prevents CMV reactivation in alloHCT patients, with limited data regarding influence on post-alloHCT outcomes.

METHODS

We retrospectively examined 273 alloHCT recipients, 158 in the non-letermovir cohort (NLC), and 115 in the cohort using letermovir prophylaxis (LC). Patients that received letermovir were CMV-seropositive and met criteria for high risk of CMV reactivation.

RESULTS

Median start of letermovir was 21 days post-alloHCT, median duration of prophylaxis was 86 days. Letermovir prophylaxis demonstrated a statistically significant reduction in first CMV reactivation (at 200 days post 63.9% in the NLC vs. 35.7% in the LC; p < .001). On univariate analysis at 1 year, overall survival (OS) for NLC was 79.6% and 79.5% for LC (p = .54). Non relapse mortality (NRM) at 1 year for NLC was 12% and 12.3% for LC (p = .69). Cumulative incidence of relapse (CIR) at 1 year was 13.9% for NLC versus 17.1 for the LC (p = .27). On multivariable analysis, there was no significant difference between the two cohorts for OS, NRM, and CIR.

CONCLUSIONS

Letermovir prophylaxis started at day +21 post-alloHCT reduced CMV reactivation, with no impact on posttransplant outcomes.

Cytomegalovirus Reactivation as a Risk Factor for All-Cause Mortality in Children Undergoing Hematopoietic Stem Cell Transplantation: Experience Over Two Decades from a Tertiary Referral Center in India

The aim of the study was to analyse the burden of cytomegalovirus (CMV) disease in children undergoing hematopoietic stem cell transplantation (HSCT) and its correlation with all-cause mortality. We performed a retrospective study in children up to 18 years of age who underwent allogeneic HSCT between February 2002 to December 2021 in the pediatric blood and marrow transplantation unit. A total of 1035 patients were included where five hundred forty-three (52.4%) patients underwent matched family donor (MFD) HSCT, 213 (20.5%) underwent matched unrelated donor (MUD) HSCT; 279 (26.9%) underwent haploidentical HSCT (T cell replete in 213 and T cell depleted in 66 patients). CMV reactivation was documented in 258 (24.9% patients). CMV was seen in 39 (7.2%) MFD, 77 (36.1%) MUD, 106 T cell replete (49.7%) and 36 T cell depleted (54.5%) transplants. CMV reactivation was predominantly documented in those where donor and recipient were positive (D + /R +) for CMV serostatus (77%)) prior to HSCT. Overall mortality rate was significantly higher in the CMV positive group (103/258, 39.9%), as compared to the CMV negative group (152/777, 19.6%) (p value = 0.0001). CMV was the direct cause of death in 13/1035 children (1.2%). GvHD as a cause of death was found to be significantly higher among those with CMV (n = 32) as compared to those without CMV (n = 14) (35.6 versus 9%, p value = 0.0001). The incidence of CMV reactivation was noted in 25% of HSCT recipients, and predominantly in haploidentical HSCTs. CMV reactivation was shown to significantly impact all-cause mortality and there was a significantly increased risk of mortality due to GvHD among those with CMV reactivation.

Torque teno virus-DNA load as individual cytomegalovirus risk assessment parameter upon allogeneic hematopoietic stem cell transplantation

BACKGROUND

Immune recovery following allogeneic hematopoietic stem cell transplantation (allo-HSCT) decisively influences the occurrence of opportunistic infections, one of the leading causes of death among this group of patients. Yet, today, there are no laboratory parameters mirroring immune function sufficiently. Torque teno virus (TTV) has already proven itself as a functional immune marker in other settings.

AIMS

In this analysis, we investigated whether monitoring of TTV-DNA load in whole blood is able to provide additional information on the capacity of the immune system to control cytomegalovirus (CMV) replication in allo-HSCT recipients.

METHODS

Whole blood samples from 59 patients were collected upon allo-HSCT (between Day -7 and +10), on Day +14, +21, +28, +56, +90, and +365 post-transplant. TTV-DNA loads and other relevant clinical information were correlated with the risk of CMV infections or reactivations, defined by evidence of viral replication in blood.

RESULTS

CMV serostatus of the recipient and a TTV load below 1000 copies/mL upon allo-HSCT were significantly associated with an increased incidence of CMV infection or reactivation.

CONCLUSIONS

Quantification of TTV load in the early phase of allo-HSCT procedure could provide additional information in order to identify patients at risk for CMV infection or reactivation.

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.

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.

Relationship between certain HLA alleles and the risk of cytomegalovirus reactivation following allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Evidence is emerging to support an association between certain HLA alleles and the risk of cytomegalovirus (CMV) reactivation following allogeneic HSCT (allo-HSCT). The primary aim of this study was to identify HLA alleles associated with resistance or susceptibility to CMV reactivation.

METHODS

We studied 586 adults who underwent allo-HSCT for high-risk hematological malignancies. High resolution HLA typing data was available for recipient and donor. HLA Class I and II alleles observed at a frequency of > 5% in our population, were included in the analysis. A CMV viremia level of more than 200 IU/ml on weekly monitoring was considered to be indicative of CMV reactivation.

RESULTS

The median follow-up time in surviving patients was 21 months (range 4-74 months). The cumulative incidence of CMV reactivation at 6 months in the entire cohort was 55% (95% CI 50.8%-59.2%). Mismatched donor, increasing recipient age, occurrence of AGVHD and recipient CMV seropositivity were associated with increased risk of CMV reactivation. HLA B*07:02 (HR 0.59, 95% CI 0.40-0.83) was associated with decreased risk of CMV reactivation. Patients who developed CMV reactivation had a lower incidence of relapse, higher transplant related mortality (TRM) and lower overall survival (OS) compared to those without CMV reactivation. There was an adverse correlation of OS and TRM with increasing numbers of CMV reactivations.

CONCLUSION

We observed that HLA B*07:02 was associated with decreased risk of CMV reactivation. CMV reactivation was associated with lower relapse post-transplant, but this did not translate into a survival benefit due to higher transplant related mortality. This article is protected by copyright. All rights reserved.

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.

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.

Cytomegalovirus and other herpesviruses after hematopoietic cell and solid organ transplantation: From antiviral drugs to virus-specific T cells

Herpesviruses can either cause primary infection or may get reactivated after both hematopoietic cell and solid organ transplantations. In general, viral infections increase post-transplant morbidity and mortality. Prophylactic, preemptive, or therapeutically administered antiviral drugs may be associated with serious side effects and may induce viral resistance. Virus-specific T cells represent a valuable addition to antiviral treatment, with high rates of response and minimal side effects. Even low numbers of virus-specific T cells manufactured by direct selection methods can reconstitute virus-specific immunity after transplantation and control viral replication. Virus-specific T cells belong to the advanced therapy medicinal products, and their production is regulated by appropriate legislation; also, strict safety regulations are required to minimize their side effects.

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.

Severe allo-immune antibody-associated peripheral and central nervous system diseases after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a curative treatment for hematologic malignancies. Acute and chronic graft-versus-host disease (GvHD) are the major immune-mediated complications after alloHSCT. However, there is controversy whether neurologic complications after alloHSCT might represent manifestations of GvHD. We report three patients who acquired distinct, severe immune-mediated peripheral or central nervous system diseases after alloHSCT without other, concomitant GvHD manifestations. One patient had been diagnosed with B-cell chronic lymphocytic leukemia and two patients with high risk myelodysplastic syndrome. Patient #1 presented as LGI1- and GAD-IgG positive immune-mediated encephalitis, patient #2 was diagnosed with MOG-IgG positive encephalomyelitis, and patient #3 had chronic inflammatory polyneuropathy associated with SSA(Ro)-IgG positive Sjögren's syndrome. 100% donor chimerism was detectable in the peripheral blood in all three. The specific antibodies were undetectable in donors' and patients' blood before alloHSCT suggesting that the antibodies had arisen from the transplanted donor immune system. Early intensive immunotherapy led to improvement of clinical symptoms and stability of the neurological disease, however, at the cost of losing the graft-versus-malignancy effect in one patient. In conclusion, we provide evidence of isolated, severe allo-immune diseases of the peripheral and central nervous system as complications of alloHSCT ("neuro-GvHD"). Interdisciplinary surveillance and thorough diagnostic work-up are needed for early diagnosis and treatment of neuro-immunologic complications after alloHSCT to improve the otherwise poor outcome.

Off-Label Use of Letermovir as Preemptive Anti-Cytomegalovirus Therapy in a Pediatric Allogeneic Peripheral Blood Stem Cell Transplant

Despite the effectiveness of the currently available antiviral drugs in treating cytomegalovirus (CMV) infection, high rates of adverse effects are associated with their use. Moreover, a problem of increasing importance is the emergence of drug-resistant CMV infection. Here, we describe the first case of off-label use of letermovir (LMV) as preemptive antiviral therapy, in a pediatric allogeneic peripheral blood stem cell transplant recipient with ganciclovir-resistant CMV infection who was intolerant to foscarnet and unable to achieve viral clearance after seven doses of cidofovir. After the administration of LMV, a gradual reduction in viral load was observed and within 6 weeks of LMV treatment, after more than 6 months of positive CMV-DNAemia, the patient cleared the infection. No adverse effects associated with LMV were observed during treatment. In this pediatric study case, the off-label use of LMV for the treatment of CMV infection has been well tolerated and proved to be effective in leading to the suppression of viral replication.

Co-Reactivation of Cytomegalovirus and Epstein-Barr Virus Was Associated With Poor Prognosis After Allogeneic Stem Cell Transplantation

Reactivation of cytomegalovirus (CMV) or Epstein-Barr virus (EBV) is common after hematopoietic stem cell transplantation (HSCT). Previous researches have demonstrated that either CMV or EBV reactivation is associated with poor outcomes of HSCT. However, few studies investigate the impact of CMV and EBV co-reactivation after HSCT. In this study, we described the clinical characteristics of HSCT recipients with CMV and EBV co-reactivation (defined as CMV and EBV viremia occur at the same period of time). We conducted a longitudinal study of 247 patients who underwent HSCT in our center. A total of 24 (9.7%) patients had CMV and EBV co-reactivation. These patients showed higher incidence of viral pneumonitis (P=0.005). Patients with CMV and EBV co-reactivation had significant lower 1-year overall survival (OS) (P=0.004) and lower 1-year leukemia free survival (LFS) (P=0.016). Our further analysis suggested that duration of CMV (P=0.014), EBV (P<0.001), and CD4+CD25+ T cell counts at day 30 post-transplantation (P=0.05) are independent risk factors of virus co-reactivation. In conclusion, patients who developed co-reactivation of CMV and EBV had poor prognosis in terms of lower 1-year OS and LFS, and the CMV and EBV co-reactivation was associated with prolonged CMV or EBV duration and poor CD4+CD25+ T cell reconstitution at day 30 post-transplantation.

Cytomegalovirus DNAemia and risk of mortality in allogeneic hematopoietic stem cell transplantation: Analysis from the Spanish Hematopoietic Transplantation and Cell Therapy Group

The net impact of cytomegalovirus (CMV) DNAemia on overall mortality (OM) and nonrelapse mortality (NRM) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a matter of debate. This was a retrospective, multicenter, noninterventional study finally including 749 patients. CMV DNA monitoring was conducted by real-time polymerase chain reaction (PCR) assays. Clinical outcomes of interest were OM and NRM through day 365 after allo-HSCT. The cumulative incidence of CMV DNAemia in this cohort was 52.6%. A total of 306 out of 382 patients with CMV DNAemia received preemptive antiviral therapy (PET). PET use for CMV DNAemia, but not the occurrence of CMV DNAemia, taken as a qualitative variable, was associated with increased OM and NRM in univariate but not in adjusted models. A subcohort analysis including patients monitored by the COBAS Ampliprep/COBAS Taqman CMV Test showed that OM and NRM were comparable in patients in whom either low or high plasma CMV DNA threshold (<500 vs ≥500 IU/mL) was used for PET initiation. In conclusion, CMV DNAemia was not associated with increased OM and NRM in allo-HSCT recipients. The potential impact of PET use on mortality was not proven but merits further research.

Clinical and economic impact of treated CMV infection in adult CMV-seropositive patients after allogeneic hematopoietic cell transplantation

OBJECTIVE

Recipients of allogeneic hematopoietic stem cell transplantation (allo-HCT) with positive cytomegalovirus (CMV) serology are at increased risk of morbidity and mortality. The primary objective of this study was to assess the association between treated CMV infection and overall mortality within 1 year after allo-HCT in adult CMV-seropositive Recipients (R+). Secondary objectives included overall 5-year mortality after allo-HCT, risk factors for treated CMV infection, associations between treated CMV infection and allo-HCT complications and medical costs.

METHODS

A multicenter retrospective cohort study was conducted in adult CMV-seropositive recipients (R+) who underwent to allo-HCT between 1st January 2010 and 31st December 2014.

RESULTS

Five hundred seventy two CMV-seropositive patients (mean age, 50.2 years) undergoing allo-HCT between 2010 and 2014 were included; 55.9% of donors were CMV seropositive. CMV infection treated with antiviral therapy was reported in 227 patients (39.7%) after transplantation. One-year overall mortality was significantly increased in patients with treated CMV infections (hazard ratio, 1.86; 95% CI, 1.16-3.00; P = .011). Mean medical costs during the first post-HCT year were higher in patients with CMV infection (€46 853 vs €31 318; P < .0001).

CONCLUSION

In this large cohort of CMV-seropositive patients undergoing allo-HCT, treated CMV infection was significantly associated with an increased 1-year risk of overall mortality, with increased length of stay and with hospitalization cost. The burden of CMV disease in allo-HCT could be reduced in the future by appropriate prophylactic strategies.

The impact of donor full-length KIR2DS4 in the development of acute and chronic GVHD after unrelated allogeneic HSCT

BACKGROUND

Killer Ig-like receptor 2DS4 (KIR2DS4) is the most prevalent activating killer Ig-like receptor gene. It is divergent and encodes either full-length or deleted allele variants. The studies of donor killer KIR2DS4 in unrelated allogeneic hematopoietic stem cell transplantations were limited.

METHODS

KIR and HLA genotyping were determined in 75 pairs of Chinese pediatric hematologic malignancy patients.

RESULTS

Among the 75 donor-recipient pairs, 77.3% (58/75) of the donors were positive for full-length KIR2DS4 and 22.7% (17/75) were negative. Patients who had donors positive for full-length KIR2DS4 had higher cumulative incidence of aGVHD than patients whose donor negative for full-length KIR2DS4 (86.2% versus 76.5%, P = .038). Multivariate analysis showed full-length KIR2DS4 was the significant factor for I-IV aGVHD (HR = 2.166, 95% CI: 1.01-4.26, P = .025). Subgroup analysis showed that AML and CML patients who received donors negative for full-length KIR2DS4 have a higher cumulative incidences of cGVHD (75% vs 62%, P = .008). There were no significant effects of full-length KIR2DS4 on overall survival (P = .13), relapse-free survival (P = .14), CMV reactivation (P = .52), and relapse (HR = 0.38, 95% CI: 0.09-1.6, P = .1875).

CONCLUSIONS

Our findings indicated a significant correlation of donor full-length KIR2DS4 on aGVHD and cGVHD. These results suggested that combining KIR and HLA genotyping may help make a better sense of transplants in these patients.

Compatibility at amino acid position 98 of MICB reduces the incidence of graft-versus-host disease in conjunction with the CMV status

Graft-versus-host disease (GVHD) and cytomegalovirus (CMV)-related complications are leading causes of mortality after unrelated-donor hematopoietic cell transplantation (UD-HCT). The non-conventional MHC class I gene MICB, alike MICA, encodes a stress-induced polymorphic NKG2D ligand. However, unlike MICA, MICB interacts with the CMV-encoded UL16, which sequestrates MICB intracellularly, leading to immune evasion. Here, we retrospectively analyzed the impact of mismatches in MICB amino acid position 98 (MICB98), a key polymorphic residue involved in UL16 binding, in 943 UD-HCT pairs who were allele-matched at HLA-A, -B, -C, -DRB1, -DQB1 and MICA loci. HLA-DP typing was further available. MICB98 mismatches were significantly associated with an increased incidence of acute (grade II-IV: HR, 1.20; 95% CI, 1.15 to 1.24; P < 0.001; grade III-IV: HR, 2.28; 95% CI, 1.56 to 3.34; P < 0.001) and chronic GVHD (HR, 1.21; 95% CI, 1.10 to 1.33; P < 0.001). MICB98 matching significantly reduced the effect of CMV status on overall mortality from a hazard ratio of 1.77 to 1.16. MICB98 mismatches showed a GVHD-independent association with a higher incidence of CMV infection/reactivation (HR, 1.84; 95% CI, 1.34 to 2.51; P < 0.001). Hence selecting a MICB98-matched donor significantly reduces the GVHD incidence and lowers the impact of CMV status on overall survival.

Murine cytomegalovirus dissemination but not reactivation in donor-positive/recipient-negative allogeneic kidney transplantation can be effectively prevented by transplant immune tolerance

Cytomegalovirus (CMV) reactivation from latently infected donor organs post-transplantation and its dissemination cause significant comorbidities in transplant recipients. Transplant-induced inflammation combined with chronic immunosuppression has been thought to provoke CMV reactivation and dissemination, although sequential events in this process have not been studied. Here, we investigated this process in a high-risk donor CMV-positive to recipient CMV-negative allogeneic murine kidney transplantation model. Recipients were either treated with indefinite immunosuppression or tolerized in a donor-specific manner. Untreated recipients served as controls. Kidney allografts from both immunosuppressed and tolerized recipients showed minimal alloimmunity-mediated graft inflammation and normal function for up to day 60 post-transplantation. However, despite the absence of such inflammation in the immunosuppressed and tolerized groups, CMV reactivation in the donor positive kidney allograft was readily observed. Interestingly, subsequent CMV replication and dissemination to distant organs only occurred in immunosuppressed recipients in which CMV-specific CD8 T cells were functionally impaired; whereas in tolerized recipients, host anti-viral immunity was well-preserved and CMV dissemination was effectively prevented. Thus, our studies uncoupled CMV reactivation from its dissemination, and underscore the potential role of robust transplantation tolerance in preventing CMV diseases following allogeneic kidney transplantation.

The Current Status of Cytomegalovirus (CMV) Prevalence in the MENA Region: A Systematic Review

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus worldwide. According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), CMV infects people of all ages, and by the age of five, approximately one-third of children in the United States are infected. Although the infection is generally asymptomatic, it can cause severe disease in immunocompromised patients, transplant and transfusion recipients, as well as newborn neonates. The objective of this study is to systematically review published literature on CMV in the MENA region to estimate its incidence in the region and describe its epidemiological and clinical significance. The literature was searched through four scientific databases: PubMed, Scopus, Science Direct, and Web of Science. A total of 72 studies from 11 countries satisfied the inclusion criteria, covering a period from 1988-2019. The CMV IgG seroprevalence ranged from 8.7%-99.2% (SD = 38.95%). CMV incidence in these countries ranged between 1.22% and 77% in transplant and transfusion recipients, with an increase in incidence with advanced age. However, the incidence rate was unclear for congenital CMV due to the variability of the reporting. This review highlights the need for more robust and well-designed studies to better estimate CMV incidence in the MENA region, standardize diagnostic criteria, and consider prophylactic and pre-emptive treatments to limit the morbidity and mortality of the disease.

Cytomegalovirus (CMV) infection and risk of mortality in allogeneic hematopoietic stem cell transplantation (Allo-HSCT): A systematic review, meta-analysis, and meta-regression analysis

Controversy surrounds the potential association between cytomegalovirus (CMV) infection and increased risk of mortality after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). A systematic literature search was conducted using the PubMed, EMBASE, and Web of Science databases, assessing the association between CMV infection, as documented by the pp65 antigenemia assay or by polymerase chain reaction (PCR) using blood specimens, and overall mortality (OM) and nonrelapse mortality (NRM) in the allo-HSCT setting. Pooled effects were estimated using the generic inverse variance random effects model. Heterogeneity was evaluated by Cochrane's Q test and I² statistics. The source of heterogeneity was investigated by meta-regression and subgroup analyses. Twenty-six of 1367 studies fulfilled eligibility criteria. CMV infection identified by PCR monitoring was significantly associated with an increased risk of OM and NRM (hazard ratio 1.47, 95% confidence interval [1.20-1.81], P ≤ .001; hazard ratio 1.68, 95% confidence interval [1.14-2.49], P = .05, respectively). In this setting, the use of preemptive antiviral therapy (PET) resulted in a twofold increased risk of OM and NRM. The estimated effect sizes were associated with allo-HSCT modalities. Although our analyses point to an association between CMV infection and an increased risk of OM and NRM in allo-HSCT recipients, the high heterogeneity across studies prevented drawing of robust conclusions on this matter.

Comprehensive viromewide antibody responses by systematic epitope scanning after hematopoietic cell transplantation

Further insight into humoral viral immunity after hematopoietic cell transplantation (HCT) could have potential impact on donor selection or monitoring of patients. Currently, estimation of humoral immune recovery is inferred from lymphocyte counts or immunoglobulin levels and does not address vulnerability to specific viral infections. We interrogated the viral antibody repertoire before and after HCT using a novel serosurvey (VirScan) that detects immunoglobulin G responses to 206 viruses. We performed VirScan on cryopreserved serum from pre-HCT and 30, 100, and 365 days after myeloablative HCT from 37 donor-recipient pairs. We applied ecologic metrics (α- and β-diversity) and evaluated predictors of metrics and changes over time. Donor age and donor/recipient cytomegalovirus (CMV) serostatus and receipt systemic glucocorticoids were most strongly associated with VirScan metrics at day 100. Other clinical characteristics, including pre-HCT treatment and conditioning, did not affect antiviral repertoire metrics. The recipient repertoire was most similar (pairwise β-diversity) to that of donor at day 100, but more similar to pre-HCT self by day 365. Gain or loss of epitopes to common viruses over the year post-HCT differed by donor and recipient pre-HCT serostatus, with highest gains in naive donors to seropositive recipients for several human herpesviruses and adenoviruses. We used VirScan to highlight contributions of donor and recipient to antiviral humoral immunity and evaluate longitudinal changes. This work builds a foundation to test whether such systematic profiling could serve as a biomarker of immune reconstitution, predict clinical events after HCT, or help refine selection of optimal donors.

PTX3 Polymorphisms Influence Cytomegalovirus Reactivation After Stem-Cell Transplantation

Background: Reactivation of latent human cytomegalovirus (CMV) in patients undergoing allogeneic stem-cell transplantation (HSCT) predisposes to several clinical complications and is therefore a major cause of morbidity and mortality. Although pentraxin-3 (PTX3) has been previously described to bind both human and murine CMV and mediate several host antiviral mechanisms, whether genetic variation in the PTX3 locus influences the risk of CMV infection is currently unknown.

Methods: To dissect the contribution of genetic variation within PTX3 to the development of CMV infection, we analyzed described loss-of-function variants at the PTX3 locus in 394 recipients of HSCT and their corresponding donors and assessed the associated risk of CMV reactivation.

Results: We report that the donor, but not recipient, h2/h2 haplotype in PTX3 increased the risk of CMV reactivation after 24 months following transplantation, with a significant effect on survival. Among recipients with h2/h2 donors, CMV seropositive patients as well as those receiving grafts from unrelated donors, regardless of the CMV serostatus, were more prone to develop viral reactivation after transplantation. Most importantly, the h2/h2 haplotype was demonstrated to display an influence toward risk of CMV reactivation comparable to that conferred by the unrelated status of the donor alone.

Conclusions: Our findings demonstrate the important contribution of genetic variation in donor PTX3 to the risk of CMV reactivation in patients undergoing HSCT, highlighting a promising prognostic value of donor PTX3 to predict risk of CMV reactivation in this clinical setting.

Association of Epstein‑Barr virus infection with allogeneic hematopoietic stem cell transplantation in patients in Portugal

The identification of patients at higher risk of developing Epstein-Barr virus (EBV) infection in hematopoietic stem cell transplants (HSCT) is useful for the prevention of EBV-associated diseases A prospective observational study was developed that included 40 patients (27 male and 13 females, with mean age of 32.2±1.5 years old) undergoing allogeneic-HSCT between January and December 2015. EBV was examined in whole blood samples collected during routine procedures at day (D)+30, D +60, +90, D+120, D+150 and D+180 post-transplant. EBV was detected, at least once during the follow-up period in 70.0% of our patients. Results indicated that patients with unrelated donors had increased risk of developing EBV infection at D+60 and D+150 (OR=3.9, P=0.058; OR=8.0, P=0.043; respectively). Moreover, myeloablative conditioning (OR=4.3, P=0.052), anti-thymocyte globulin use (OR=12.0, P=0.030) and graft-vs.-host disease (OR=6.7, P=0.032) were associated with EBV infection at D+60, D+150 and D+90, respectively. In our series, none of these patients developed post-transplant lymphoproliferative disease. To the best of our knowledge, the present study is the first study to report EBV infection in patients undergoing aHSCT from Portugal. The study revealed that EBV infection is associated with different factors. These findings provide evidence towards the identification of high-risk patients for EBV-infection and associated disease.

Safety analysis in patients with autoimmune disease receiving allogeneic mesenchymal stem cells infusion: a long-term retrospective study

Objective

The aim of this study was to evaluate the safety of mesenchymal stem cell infusion in patients with autoimmune diseases.

Methods

A total of 404 patients with autoimmune diseases who received mesenchymal stem cell infusion between 2007 and 2016 were included in this study. Adverse events in these patients were collected, mainly including infections and malignancies. Sources of information included hospitalization records and data from outpatient visits and each follow-up.

Results

The mean follow-up period of all patients was 43.4 ± 25.9 months (range 1–109). Majority of stem cells were from the umbilical cord. The most common indications for mesenchymal stem cell infusion were systemic lupus erythematosus, Sjögren’s syndrome, and systemic sclerosis. The median age at infusion was 38.7 ± 15.7 years. The 5-year and 8-year survival rates were 90.4% and 88.9%, respectively. Median follow-up of survivors was 45.1 ± 25.7 months. The incidence rate of infections was 29.5% (119/404), and that of serious infections was 12.9% (52/404). Five patients (1.2%) experienced malignancies. Deaths occurred in 45 patients, and transplantation-related mortality was 0.2%. The most common causes of deaths in our study were disease relapse and complications associated with the underlying disease.

Conclusion

Autoimmune disease is an emerging indication for mesenchymal stem cell infusion. Our data shows that mesenchymal stem cell infusion is a safe therapy for patients with autoimmune diseases. The incidences of adverse events, whether infections or malignancies, are acceptable in these patients.

Trial registration

ClinaicalTrials.gov, NCT00698191. Registered 17 June 2008—Retrospectively registered

The clinical and economic impact of cytomegalovirus infection in recipients of hematopoietic stem cell transplantation

BACKGROUND

CMV infection (CMV-I) remains an important complication of hematopoietic stem cell transplantation (HSCT).

METHODS

This was a retrospective, single-center cohort study in HSCT recipients. Primary outcomes were adjusted cost and all-cause mortality. Secondary analyses investigated CMV risk factors and the effect of serostatus.

RESULTS

Overall, 690 transplant episodes were included (allogeneic [n = 310]; autologous [n = 380]). All received preemptive CMV antiviral therapy at first detectable DNAemia. CMV-I occurred in 34.8% of allogeneic and 2.1% of autologous transplants; median time to onset was 45 days. In allogeneic HSCT recipients, the primary risk factor for CMV-I was CMV donor/recipient (D/R) serostatus. In a Markov multi-state model for allogeneic HSCT recipients, the hazard ratio for CMV-I and relapse was 1.5 (95% CI 0.8-2.8) and for CMV-I and mortality 2.4 (95% CI 0.9-6.5). In a multivariable model for all patients, CMV-I was associated with increased total cost (coefficient = 0.21, estimated incremental daily cost USD $500; P = 0.02). Cost was attenuated in allogeneic HSCT recipients (coefficient = 0.13, USD $699 vs $613, or $24 892 per transplant episode; P = 0.23). CMV disease (CMV-D) complicated 29.6% of CMV-I events in allogeneic HSCT recipients, but was not associated with an incrementally increased adjusted risk of mortality compared with CMV-I alone. CMV-I (56.4%) and CMV-D (19.8%) were significantly overrepresented in D-/R+ serostatus HSCT recipients, and mortality was higher in R+ HSCT recipients.

CONCLUSIONS

Despite early preemptive antiviral treatment, CMV-I impacts clinical outcomes and cost after HSCT, but the impact on cost is less pronounced in allogeneic HSCT recipients compared with autologous HSCT recipients.

Repurposing Nilotinib for Cytomegalovirus Infection Prophylaxis after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Arm, Phase II Trial

Platelet-derived growth factor receptor-alpha (PDGFRa) is a critical receptor for cytomegalovirus (CMV) entry into cells, leading to subsequent infection. This trial tested whether PDGFRa inhibition by nilotinib could prevent CMV infection in patients after allogeneic stem cell transplantation (allo-HSCT). Nilotinib (200 mg/day) was given continuously after engraftment, and plasma CMV DNA levels were monitored weekly. The primary endpoint was successful prophylaxis of CMV infection, defined as plasma CMV DNA copies less than 10,000 copies/mL, no anti-CMV treatment initiated, and no clinical CMV disease by day 100. All 37 enrolled recipients and their donors were CMV seropositive. Thirty patients received matched sibling transplants, 15 received nonmyeloablative conditioning regimens, and 15 received antithymocyte globulin as a part of graft-versus-host disease prophylaxis. The median interval from transplantation to nilotinib treatment was 23 days, and the median duration of administration was 76 days. None of the 31 assessable patients had nilotinib-associated grade 3/4 adverse events or nilotinib discontinuation. Twenty-five of 31 assessable patients (80.6%) fulfilled the predefined criteria for successful CMV prophylaxis, and none of them had clinical CMV disease. Only 1 of 6 failed patients developed CMV colitis. Nilotinib is well tolerated in allo-HSCT recipients, and its preliminary efficacy results suggest that blocking CMV entry to prevent CMV infection may warrant further exploration. (ClinicalTrials.gov identifier: NCT01252017.).

Early human cytomegalovirus reactivation is associated with lower incidence of relapse of myeloproliferative disorders after allogeneic hematopoietic stem cell transplantation

Conflicting results have been reported regarding the association between early cytomegalovirus (CMV) reactivation and relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This prompted us to evaluate the impact of CMV reactivation on outcomes of 155 consecutive adult patients transplanted in our institution. In our study, CMV reactivation did not affect cumulative incidence (CI) of relapse in patients with lymphoproliferative disorders. However, the CI of relapse in patients with myeloproliferative disorders (AML and MPN) was 37% (95% CI, 21-53) in patients without CMV reactivation as opposed to 17% (95% CI, 9-28) in patients with CMV reactivation (p = 0.03). An important correlation between CMV reactivation and relapse was found in patients with MPN; the CI of relapse was 50% (95% CI, 12-80) in patients without CMV reactivation as opposed to only 7% (95% CI, 0-27) in patients with CMV reactivation (p = 0.02). A substantial reduction of relapse in myeloproliferative disorders associated with CMV reactivation was confirmed by multivariate analysis (HR 2.73; 95% CI, 1.09-6.82, p = 0.03) using time-dependent covariates for high-risk disease, older age, RIC conditioning, ATG, grade II-IV acute, and chronic GVHD. To our knowledge, we are the first to show an association of CMV reactivation with relapse reduction in MPN patients. This putative virus vs myeloproliferation effect warrants further research.

Navigating the Host Cell Response during Entry into Sites of Latent Cytomegalovirus Infection

The host cell represents a hostile environment that viruses must counter in order to establish infection. Human cytomegalovirus (HCMV) is no different and encodes a multitude of functions aimed at disabling, re-directing or hijacking cellular functions to promulgate infection. However, during the very early stages of infection the virus relies on the outcome of interactions between virion components, cell surface receptors and host signalling pathways to promote an environment that supports infection. In the context of latent infection—where the virus establishes an infection in an absence of many gene products specific for lytic infection—these initial interactions are crucial events. In this review, we will discuss key host responses triggered by viral infection and how, in turn, the virus ameliorates the impact on the establishment of non-lytic infections of cells. We will focus on strategies to evade intrinsic antiviral and innate immune responses and consider their impact on viral infection. Finally, we will consider the hypothesis that the very early events upon viral infection are important for dictating the outcome of infection and consider the possibility that events that occur during entry into non-permissive cells are unique and thus contribute to the establishment of latency.

Cytomegalovirus Infection and Treatment in Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Study from a Single Institution in an Endemic Area

Objective:

Although Cytomegalovirus (CMV) infection is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT), the risk factors for CMV reactivation and treatment failure in CMV endemic areas have remained unclear. This study investigated the risk factors for CMV reactivation among allo-HSCT recipients in an area where CMV is highly endemic.

Materials and Methods:

Medical records of 82 allo-HSCT recipients from a CMV endemic area were retrospectively reviewed. The patients were stratified into two groups: those with CMV reactivation (n=32) and those without CMV reactivation (n=50). We investigated possible variables associated with CMV reactivation and treatment failure.

Results:

Univariate analyses showed that non-remission disease status [hazard ratio (HR): 2.15; p=0.032] and ≥grade III acute graft-versus-host disease (GVHD) (HR: 3.07; p=0.002) were associated with CMV reactivation. Multivariate analysis further demonstrated that older age (HR: 1.03; p=0.029) and ≥grade III acute GVHD (HR: 2.98; p=0.012) were associated with CMV reactivation. Overall survival time seemed lower among patients with CMV reactivation than among patients without CMV reactivation, although the difference was not statistically significant (p=0.165). The absence of ≥grade III acute GVHD was associated with successful CMV treatment in the current study (odds ratio: 4.40; p=0.008).

Conclusion:

Prophylactic anti-CMV therapy might need to be considered for allo-HSCT recipients who have ≥grade III GVHD.

Effect of Cytomegalovirus Reactivation on Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Acute Leukemia

Recent studies have demonstrated the protective effect of cytomegalovirus (CMV) reactivation against relapse after allogeneic hematopoietic stem cell transplantation (HSCT) for adult myeloid malignancies. We assessed the association of CMV reactivation, defined as the development of CMV antigenemia (at least 1 pp65 antigen-positive cell per 5.0 × 10(4) WBCs) within 100 days after HSCT, with the risk of relapse in 143 patients with pediatric acute leukemia. The median age at HSCT was 7 years, and underlying diseases included acute lymphoblastic leukemia in 101 patients and acute myeloid leukemia in 42. The cumulative incidence of CMV reactivation at day 100 after HSCT was 45.4%. At a median follow-up of 88 months, patients with CMV reactivation had significantly lower 5-year cumulative incidence of relapse compared with patients without CMV reactivation. In a multivariate analysis, high-level CMV reactivation (≥10 pp65 antigen-positive cells) was an independent factor associated with reduced relapse. However, CMV reactivation was also associated with higher nonrelapse mortality (NRM), mostly caused by opportunistic infection after grades II to IV acute graft-versus-host disease (GVHD), which resulted in decreased probability of survival. High-level CMV reactivation was a risk factor for increased NRM and worse overall survival in multivariate analysis. Although CMV reactivation may reduce the risk of relapse after HSCT for pediatric acute leukemia, effective management of severe acute GVHD and better prophylaxis and treatment of opportunistic infections are required to reduce the incidence of NRM and improve survival. Further studies on pediatric HSCT that include a larger number of patients and more homogenous patient cohorts are desirable.

Risk factors and outcomes of cytomegalovirus viremia in pediatric hematopoietic stem cell transplantation patients

BACKGROUND

Cytomegalovirus (CMV) is a major pathogen causing significant mortality and morbidity in immunocompromised hosts. It is important to find risk factors associated with CMV viremia and its outcome.

METHODS

We investigated the incidence, time of onset, risk factors for CMV viremia, and characteristics of CMV diseases in 57 pediatric patients receiving hematopoietic stem cell transplantation (HSCT). Between August 2011 and March 2014, cases of pediatric HSCT patients at the National Taiwan University Children's Hospital were reviewed. Viremia was identified by plasma CMV real-time polymerase chain reaction (RT-PCR) assay.

RESULTS

Eighteen (32%) of the 57 patients developed CMV viremia at a median of 23 days post-HSCT (range -3 to +721 days). Eighty-nine percent (16/18) of CMV viremia occurred within 100 days posttransplantation. Four patients finally had CMV diseases (1 with CMV colitis and 3 with CMV pneumonitis) and one patient died of CMV pneumonitis complicated with pulmonary hemorrhage and sepsis. Significant risk factors associated with CMV viremia via univariate analysis include older age (p = 0.03), leukemic patients [odds ratio (OR): 5.2, 95% confidence interval (CI): 1.52∼17.7, p = 0.008), allogeneic HSCT (OR: 14.57, 95% CI: 1.76∼120.5, p = 0.002), antithymoglobulin (ATG) use before transplantation (OR: 5.09, 95% CI: 1.52∼16.9, p = 0.007), graft-versus-host disease (GvHD) (OR: 10.1, 95% CI: 2.7∼38.7, p < 0.001), and gastrointestinal GvHD (OR: 10.9, 95% CI: 2.72∼43.9, p = 0.001).

CONCLUSION

In pediatric posttransplantation patients, CMV viremia mostly occurred within 100 days after transplantation. Risk factors associated with CMV viremia include older diagnostic age, leukemic patients, unrelated donor HSCT, pretransplant ATG use, GvHD, and gastrointestinal GvHD.