The impact of cytomegalovirus serostatus of donor and recipient before hematopoietic stem cell transplantation in the era of antiviral prophylaxis and preemptive therapy

Association of the areas over and under the lymphocyte curve with cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation

BACKGROUND

We retrospectively compared the impact of the areas over and under the lymphocyte curve (L_AOC vs L_AUC) on cytomegalovirus (CMV) reactivation after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Among 394 consecutive patients who underwent their first allogeneic HSCT at our center between 2007 and 2018, 301 patients met the inclusion criteria. L_AOC was calculated as the area over the lymphocyte curve during lymphopenia (absolute lymphocyte count [ALC] <700/μL). We calculated L_AOC and L_AUC from day 0 to day 15 (L_AOC15, L_AUC15) and from day 0 to day 30 (L_AOC30, L_AUC30).

RESULTS

CMV antigenemia was defined as more than 3 cells/2 slides by the C10/11 method and detected in 204 cases (CMV reactivation) at a median of 39 days after HSCT. Although there were significant differences in L_AOC15, L_AOC30, L_AUC15, and L_AUC30 between patients with and without CMV reactivation, there was no difference in accuracy for predicting CMV reactivation between L_AOC and L_AUC. In a multivariate analysis, L_AOC15 and L_AUC15 were each identified as independent predictive factors for CMV reactivation, along with advanced age and CMV serostatus. However, ALC at day 14 or day 21 was as accurate as area-based indexes such as L_AOC15 and L_AUC15. L_AOC15 and L_AUC15 were significantly associated with longer duration of anti-CMV antiviral therapy while ALC was not.

CONCLUSIONS

L_AOC15 and L_AUC15 had similar impacts on CMV reactivation. Although these area-based indexes were not superior to ALC for predicting CMV reactivation, they might predict patients who need longer duration of antiviral therapy more accurately.

Hematopoietic cell transplant outcomes after myeloablative conditioning with fludarabine, busulfan, low-dose total body irradiation, and rabbit antithymocyte globulin

Optimal conditioning and graft-vs-host disease (GVHD) prophylaxis for hematopoietic cell transplantation (HCT) are unknown. Here, we report on outcomes after low toxicity, myeloablative conditioning consisting of fludarabine, busulfan, and 4 Gy total body irradiation, in combination with thymoglobulin and post-transplant methotrexate and cyclosporine. We retrospectively studied 700 patients with hematologic malignancies who received blood stem cells from 7 to 8/8 HLA-matched unrelated or related donors. Median follow-up of surviving patients was 5 years. At 5 years, overall survival (OS), relapse-free survival (RFS), and chronic GVHD/relapse-free survival (cGRFS) were 58%, 55%, and 40%. Risk factors for poor OS, RFS, and cGRFS were (1). high to very high disease risk index (DRI), (2). high recipient age, and (3). cytomegalovirus (CMV)-seropositive recipient with seronegative donor (D-R+). The latter risk factor applied particularly to patients with lymphoid malignancies. Neither donor other than HLA-matched sibling (7-8/8 unrelated) nor one HLA allele mismatch was risk factors for poor OS, RFS, or cGRFS. In conclusion, the above regimen results in excellent long-term outcomes. The outcomes are negatively impacted by older age, high or very high DRI, and CMV D-R+ serostatus, but not by donor unrelatedness or one HLA allele mismatch.

Cytomegalovirus Latency and Reactivation: An Intricate Interplay With the Host Immune Response

CMV is an ancient herpesvirus that has co-evolved with its host over millions of years. The 236 kbp genome encodes at least 165 genes, four non-coding RNAs and 14 miRNAs. Of the protein-coding genes, 43-44 are core replication genes common to all herpesviruses, while ~30 are unique to betaherpesviruses. Many CMV genes are involved in evading detection by the host immune response, and others have roles in cell tropism. CMV replicates systemically, and thus, has adapted to various biological niches within the host. Different biological niches may place competing demands on the virus, such that genes that are favorable in some contexts are unfavorable in others. The outcome of infection is dependent on the cell type. In fibroblasts, the virus replicates lytically to produce infectious virus. In other cell types, such as myeloid progenitor cells, there is an initial burst of lytic gene expression, which is subsequently silenced through epigenetic repression, leading to establishment of latency. Latently infected monocytes disseminate the virus to various organs. Latency is established through cell type specific mechanisms of transcriptional silencing. In contrast, reactivation is triggered through pathways activated by inflammation, infection, and injury that are common to many cell types, as well as differentiation of myeloid cells to dendritic cells. Thus, CMV has evolved a complex relationship with the host immune response, in which it exploits cell type specific mechanisms of gene regulation to establish latency and to disseminate infection systemically, and also uses the inflammatory response to infection as an early warning system which allows the virus to escape from situations in which its survival is threatened, either by cellular damage or infection of the host with another pathogen. Spontaneous reactivation induced by cellular aging/damage may explain why extensive expression of lytic genes has been observed in recent studies using highly sensitive transcriptome analyses of cells from latently infected individuals. Recent studies with animal models highlight the potential for harnessing the host immune response to blunt cellular injury induced by organ transplantation, and thus, prevent reactivation of CMV and its sequelae.

The direct and indirect consequences of cytomegalovirus infection and potential benefits of vaccination

Active infection with cytomegalovirus (CMV) occurs in patients who are immunocompromised and may produce the high viral loads required to cause end-organ disease. Such patients have complex medical histories and many experienced physicians have speculated that CMV may, additionally, contribute to adverse clinical outcomes. In 1989, Dr Bob Rubin coined the term "indirect effects" to describe this potential relationship between virus and patient. Examples include accelerated atherosclerosis in patients after heart transplant or with underlying HIV infection, the number of days patients require ventilation after admission to intensive care units, the development of immunosenescence in the elderly and mortality in many groups of patients, including the general population. It is difficult to distinguish between CMV acting as causal contributor to such diverse pathology or simply having a benign bystander effect. However, recruitment of patients into placebo-controlled randomised trials of antiviral drugs with activity against CMV offers such a potential. This article describes the studies that have been conducted to date and emphasises that mortality after stem cell transplant (not attributed to CMV end-organ disease) has recently become the first proven indirect effect of CMV now that letermovir has significantly reduced non-relapse deaths. The implications for CMV vaccines are then discussed. Vaccines are already predicted to be highly cost-effective if they can reduce CMV end-organ disease. Health planners should now consider that cost effectiveness is likely to be enhanced further through reduction of the indirect effects of CMV. A prototype scheme for assessing this possibility is provided in order to stimulate discussion within the field. This article forms part of an online symposium on the prevention and therapy of DNA virus infections, dedicated to the memory of Mark Prichard.

The Ability of a Cytomegalovirus ELISPOT Assay to Predict Outcome of Low-Level CMV Reactivation in Hematopoietic Cell Transplant Recipients

BACKGROUND

Cytomegalovirus (CMV) infections in hematopoietic cell transplant (HCT) recipients cause substantial morbidity and mortality. CMV cell-mediated immunity (CMV-CMI) can be determined by levels of interferon gamma (IFN-γ) production using an enzyme-linked immunospot (ELISPOT) CMV assay (T-SPOT.CMV assay). In this study, we evaluated the ability of this assay to predict the outcome of low-level CMV reactivation in HCT recipients.

METHODS

We followed 55 HCT recipients with low-level CMV reactivation up to 8 weeks from enrollment. Progression to clinically significant CMV infection (CS-CMVi) was defined as a CMV load >1000 IU/mL or > 500 IU/mL in patients receiving matched related/autologous or matched unrelated transplants, respectively, and initiation of antiviral treatment.

RESULTS

Progression to CS-CMVi occurred in 31 (56%) of the HCT recipients. Spot counts of CMV-specific pp65 and IE1 antigens were significantly lower in patients who had CS-CMVi than in patients who did not. On multivariate analysis, the ELISPOT CMV responses and steroids use were the only predictors of progression to CS-CMVi.

CONCLUSIONS

A strong association between low CMV-CMI and progression to CS-CMVi was observed in HCT recipients. The implementation of serial monitoring of CMV-CMI may identify patients at risk of progression to CS-CMVi that require antiviral therapy.

Human cytomegalovirus seropositivity is associated with decreased survival in glioblastoma patients

Background

Human cytomegalovirus (HCMV) is an oncomodulatory human herpesvirus that has been detected in glioblastoma (GBM) and is associated with worse prognosis in patients with the disease. The effects of HCMV systemic infection on survival in GBM patients, however, are largely unknown. We aimed to determine the association between HCMV serostatus at diagnosis and survival via a retrospective cohort study of GBM patients.

Methods

Plasma from 188 GBM patients treated at the Ben and Catherine Ivy Center (Seattle, WA) was tested for HCMV serostatus via enzyme-linked immunosorbent assays of anti-HCMV immunoglobulin (Ig)G. HCMV IgG serostatus was analyzed with respect to each patient’s progression-free and overall survival (OS) via log-rank and multivariable Cox regression analysis.

Results

Ninety-seven of 188 (52%) patients were anti-HCMV IgG seropositive. Median OS was decreased in the IgG+ cohort (404 days) compared to IgG− patients (530 days; P = .0271). Among O⁶-methylguanine-DNA methyltransferase (MGMT) unmethylated patients (n = 96), median OS was significantly decreased in IgG+ patients (336 days) compared to IgG− patients (510 days; P = .0094). MGMT methylation was associated with improved OS in IgG+ patients versus those who were unmethylated (680 vs 336 days; P = .0096), whereas no such association was observed among IgG− patients.

Conclusions

In this study, HCMV seropositivity was significantly associated with poorer OS in GBM patients. This finding suggests prior infection with HCMV may play an important role in GBM patient outcomes, and anti-HCMV antibodies may, therefore, prove a valuable prognostic tool in the management of GBM patients.

An update on the treatment of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Introduction: Human Cytomegalovirus (CMV) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Standard treatment options have for long been limited to a small number of effective drugs with significant toxicities.Areas covered: In this manuscript, the authors update a previous review summarizing recent developments in the virology lab and their possible implications for treatment strategies at bedside. In particular, the authors focused on new antiviral drugs already available and under investigation in clinical trials and innovative immunotherapeutic approaches, including adoptive T-cell therapy and vaccines.Expert opinion: Broader knowledge of CMV biology and its relationship with the host immune system is greatly contributing to the development of novel therapeutic approaches. The availability of new drugs, the improved techniques for virological testing and the more accurate patient risk stratification allow to better individualize treatment, limiting toxicity while sparing antiviral effects. The role of immunotherapy is clearly emerging and will further expand our treatment armamentarium.

Clinical significance of post-treatment viral load of cytomegalovirus in patients with hematologic malignancies

OBJECTIVES

Patients with hematologic diseases were at high risk for cytomegalovirus (CMV) diseases. In the present study, we compare various prognostic factors during CMV viremia, with specific emphasis on the relationship between viremia eradication and the long-term prognosis of patients after each episode.

METHODS

Adult patients with hematologic diseases who had a detectable CMV viral load (VL) (equal to or above 150 copies/mL) were included in the study. Medical records were reviewed for demographic data including age, sex, hematologic and other underlying diseases, status of stem cell transplantation, antiviral medication, serum CMV viral load before and after antiviral treatment.

RESULTS

A total of 101 episodes of CMV viremia occurred in patients with hematologic diseases. Comparison of various prognostic factors revealed non-survivors more frequently suffered from pneumonia and concomitant bacterial or fungal infections, had less frequently undergone hematopoietic stem cell transplantation (HSCT), and had higher peak VLs during viremic episodes. After antiviral therapy, eradication of viremia was much less frequently achieved in non-survivors. The Kaplan-Meier curves revealed that patients with detectable end-treatment VL had lower survival rates even if the antivirals were administered for more than 21 days. In a multivariate Cox proportional-hazard model, a detectable VL at the end of antiviral therapy independently predicted mortality within 180 days.

CONCLUSIONS

In patients with hematologic diseases suffering CMV viremia, failure to eradicate viremia after antiviral therapy indicates a higher chance of mortality and can be regarded as a useful indicator in evaluating the patient's long-term prognosis.

Battle between Host Immune Cellular Responses and HCMV Immune Evasion

Human cytomegalovirus (HCMV) is ubiquitously prevalent. HCMV infection is typically asymptomatic and controlled by the immune system in healthy individuals, yet HCMV can be severely pathogenic for the fetus during pregnancy and in immunocompromised persons, such as transplant recipients or HIV infected patients. HCMV has co-evolved with the hosts, developed strategies to hide from immune effector cells and to successfully survive in the human organism. One strategy for evading or delaying the immune response is maintenance of the viral genome to establish the phase of latency. Furthermore, HCMV immune evasion involves the downregulation of human leukocyte antigens (HLA)-Ia molecules to hide infected cells from T-cell recognition. HCMV expresses several proteins that are described for downregulation of the HLA class I pathway via various mechanisms. Here, we review the wide range of immune evasion mechanisms of HCMV. Understanding the mechanisms of HCMV immune evasion will contribute to the development of new customized therapeutic strategies against the virus.

Letermovir for the prevention of cytomegalovirus infection and disease in transplant recipients: an evidence-based review

Cytomegalovirus (CMV) is a leading opportunistic infection in immune compromised patients, including allogeneic hematopoietic stem cell (HSCT) or solid organ transplant (SOT) recipients, where primary infection or reactivation is associated with increased morbidity and mortality. Antiviral drugs are the mainstay for the prevention of CMV infection and disease, most commonly with valganciclovir. However, valganciclovir use is often associated with adverse drug reactions, most notably leukopenia and neutropenia, and its widespread use has led to emergence of antiviral resistance. Foscarnet and cidofovir, however, are associated with nephrotoxicity. Letermovir, a novel CMV viral terminase inhibitor drug, was recently approved for CMV prophylaxis in allogeneic HSCT recipients. It has a favorable pharmacokinetic and tolerability profile. The aim of this paper is to review the evidence supporting the use of letermovir in allogeneic HSCT recipients, and how the drug impacts our contemporary clinical practice. In addition, we discuss the ongoing clinical trial of letermovir for the prevention of CMV in SOT recipients. The use of letermovir for treatment of CMV infection and disease is not yet approved. However, because of a unique mechanism of activity, we provide our perspective on the potential role of letermovir in the treatment of ganciclovir-resistant CMV infection and disease. Furthermore, drug-resistant CMV has emerged during use of letermovir for prophylaxis and treatment. Caution is advised on its use in order to preserve its therapeutic lifespan.

Guidelines for the management of cytomegalovirus infection in patients with haematological malignancies and after stem cell transplantation from the 2017 European Conference on Infections in Leukaemia (ECIL 7)

Cytomegalovirus is one of the most important infections to occur after allogeneic haematopoietic stem cell transplantation (HSCT), and an increasing number of reports indicate that cytomegalovirus is also a potentially important pathogen in patients treated with recently introduced drugs for hematological malignancies. Expert recommendations have been produced by the 2017 European Conference on Infections in Leukaemia (ECIL 7) after a review of the literature on the diagnosis and management of cytomegalovirus in patients after HSCT and in patients receiving other types of therapy for haematological malignancies. These recommendations cover diagnosis, preventive strategies such as prophylaxis and pre-emptive therapy, and management of cytomegalovirus disease. Antiviral drugs including maribavir and letermovir are in development and prospective clinical trials have recently been completed. However, management of patients with resistant or refractory cytomegalovirus infection or cytomegalovirus disease is a challenge. In this Review we summarise the reviewed literature and the recommendations of the ECIL 7 for management of cytomegalovirus in patients with haematological malignancies.

Human Cytomegalovirus Latency and Reactivation in Allogeneic Hematopoietic Stem Cell Transplant Recipients

Human cytomegalovirus (HCMV) reactivation is a major infectious cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). HCMV is a ubiquitous beta-herpesvirus which asymptomatically infects immunocompetent individuals but establishes lifelong latency, with the potential to reactivate to a life-threatening productive infection when the host immune system is suppressed or compromised. Opportunistic HCMV reactivation is the most common viral complication following engraftment after HSCT and is associated with a marked increase in non-relapse mortality, which appears to be linked to complex effects on post-transplant immune recovery. This minireview explores the cellular sites of HCMV latency and reactivation in HSCT recipients and provides an overview of the risk factors for HCMV reactivation post-HSCT. The impact of HCMV in shaping post-transplant immune reconstitution and its relationship with patient outcomes such as relapse and graft-versus-host disease will be discussed. Finally, we survey current and emerging strategies to prevent and control HCMV reactivation in HSCT recipients, with recent developments including adoptive T cell therapies to accelerate HCMV-specific T cell reconstitution and new anti-HCMV drug therapy for HCMV reactivation after HSCT.

The prognostic impact of the cytomegalovirus serostatus in patients with chronic hematological malignancies after allogeneic hematopoietic stem cell transplantation: a report from the Infectious Diseases Working Party of EBMT

It has been shown recently that donor and/or recipient cytomegalovirus (CMV) seropositivity is associated with a significant overall survival (OS) decline in acute leukemia patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). We now analyzed the prognostic impact of the donor/recipient CMV serostatus in 6968 patients with chronic hematological malignancies who underwent allo-HSCT. Donor and/or recipient CMV seropositivity was associated with a significantly reduced 2-year progression-free survival (PFS, 50% vs. 52%, p = 0.03) and OS (62% vs. 65%, p = 0.01). Multivariate Cox regression analyses showed an independent negative prognostic impact of donor and/or recipient CMV seropositivity on PFS (HR, 1.1; 95% CI, 1.0-1.2; p = 0.03), OS (HR, 1.1; 95% CI, 1.0-1.2; p = 0.003), and non-relapse mortality (HR, 1.2; 95% CI, 1.0-1.3; p = 0.02). OS decline was strongest for CMV-seropositive recipients with a CMV-seronegative donor (HR, 1.2; 95% CI, 1.1-1.3), followed by CMV-seropositive patients with a CMV-seropositive donor (HR, 1.1; 95% CI, 1.0-1.2). Conversely, OS did not differ significantly between CMV-seronegative recipients allografted from a CMV-seropositive donor (HR, 1.0; 95% CI, 0.9-1.2) and patients with donor/recipient CMV seronegativity (p = 0.001 for the four groups together). Non-relapse mortality was also significantly (p = 0.01) higher for CMV-seropositive patients with a CMV-seronegative graft (HR, 1.2; 95% CI, 1.1-1.4) than for CMV-seropositive patients with a CMV-seropositive graft (HR, 1.1; 95% CI, 0.9-1.2) or CMV-seronegative recipients with a CMV-seropositive graft (HR, 1.0; 95% CI, 0.8-1.2). Donor and/or recipient CMV seropositivity still results in an OS decline in patients with chronic hematological malignancies who have undergone allo-HSCT. However, this OS decline seems to be lower than that described for acute leukemia patients previously.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

Estimation of the worldwide seroprevalence of cytomegalovirus: A systematic review and meta-analysis

Cytomegalovirus (CMV) infection does not usually produce symptoms when it causes primary infection, reinfection, or reactivation because these three types of infection are all controlled by the normal immune system. However, CMV becomes an important pathogen in individuals whose immune system is immature or compromised, such as the unborn child. Several vaccines against CMV are currently in clinical trials that aim to induce immunity in seronegative individuals and/or to boost the immunity of those with prior natural infection (seropositives). To facilitate estimation of the burden of disease and the need for vaccines that induce de novo immune responses or that boost pre-existing immunity to CMV, we conducted a systematic survey of the published literature to describe the global seroprevalence of CMV IgG antibodies. We estimated a global CMV seroprevalence of 83% (95%UI: 78-88) in the general population, 86% (95%UI: 83-89) in women of childbearing age, and 86% (95%UI: 82-89) in donors of blood or organs. For each of these three groups, the highest seroprevalence was seen in the World Health Organisation (WHO) Eastern Mediterranean region 90% (95%UI: 85-94) and the lowest in WHO European region 66% (95%UI: 56-74). These estimates of the worldwide CMV distribution will help develop national and regional burden of disease models and inform future vaccine development efforts.

CMV-Specific Immune Response-New Patients, New Insight: Central Role of Specific IgG during Infancy and Long-Lasting Immune Deficiency after Allogenic Stem Cell Transplantation

Although the existing paradigm states that cytomegalovirus (CMV) reactivation is under the control of the cellular immune response, the role of humoral and innate counterparts are underestimated. The study analyzed the host–virus interaction i.e., CMV-immune response evolution during infection in three different clinical situations: (1) immunodeficient CMV-positive human leukocyte antigen (HLA)-matched bone marrow recipients after immunoablative conditioning as well as immunocompetent, (2) adult, and (3) infant with primary immune response. In the first situation, a fast and significant decrease of specific immunity was observed but reconstitution of marrow-derived B and natural killer (NK) cells was observed prior to thymic origin of T cells. The lowest CMV-IgG (93.2 RU/mL) was found just before CMV viremia. It is noteworthy that the sole and exclusive factor of CMV-specific immune response is a residual recipient antibody class IgG. The CMV-quantiferon increase was detected later, but in the first phase, phytohemagglutinin (PHA)-induced IFN-γ release was significantly lower than that of CMV-induced (“indeterminate” results). It corresponds with the increase of NK cells at the top of lymphocyte reconstitution and undetected CMV-specific CD8 cells using a pentamer technique. In immunocompetent adult (CMV-negative donor), the cellular and humoral immune response increased in a parallel manner, but symptoms of CMV mononucleosis persisted until the increase of specific IgG. During infancy, the decrease of the maternal CMV-IgG level to 89.08 RU/mL followed by clinical sequel, i.e., CMV replication, were described. My observations shed light on a unique host-CMV interaction and CMV-IgG role: they indicate that its significant decrease predicts CMV replication. Before primary cellular immune response development, the high level of residual CMV-IgG (about >100 R/mL) from mother or recipient prevents virus reactivation. The innate immune response and NK-dependent IFN-secretion should be further investigated.

Virotherapy as Potential Adjunct Therapy for Graft-Vs-Host Disease

PURPOSE OF REVIEW

This review discusses the pathophysiology, risk factors, and the advances in the prevention or treatment of graft-vs-host disease (GvHD) by exploiting adjunct virotherapy. In addition, nonviral adjunct therapeutic options for the prevention of GvHD in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are discussed. The role of oncolytic viruses to treat different HSCT-eligible hematological cancers is also considered and correlated with the issue of GvHD in the context of allo-HSCT.

RECENT FINDINGS

Emerging therapies focused on the prevention or treatment of GvHD include the use of regulatory T cells (Tregs), mesenchymal stem cells (MSCs), microbiome manipulation, B cell inhibitors, among others. Our lab and others have reported that an oncolytic DNA virus from the Poxviridae family, called myxoma virus (MYXV), not only exhibits oncolytic activity against various hematologic malignancies like multiple myeloma (MM) or acute myeloid leukemia (AML) but also, in addition, ex vivo MYXV treatment of human allogeneic-bone marrow transplants (allo-BMT), or allo-peripheral blood mononuclear cell (allo-PBMC) transplants can abrogate GvHD in xenografted mice without impairing graft-vs-tumor (GvT) effects against residual cancer. To date, this is the first and the only oncolytic virus with a dual potential of mediating oncolysis against a residual cancer target and also inhibiting or preventing GvHD following allo-HSCT.

SUMMARY

This review discusses how oncolytic virotherapy can be applied as a potential adjunct therapy for the potential treatment of GvHD. In addition, we highlight major emerging nonviral therapies currently studied for the treatment or prevention of GvHD. We also review the emerging oncolytic virotherapies against different hematological cancers currently eligible for allo-HSCT and highlight the potential role of the oncolytic virus MYXV to decrease GvHD while maintaining or enhancing the positive benefits of GvT.

A Low Incidence of Cytomegalo Virus Infection Following Allogeneic Hematopoietic Stem Cell Transplantation Despite a High Seroprevalence

Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality following allogeneic stem cell transplantation (SCT). We wanted to study if the high sero-prevalence seen in our population translated into a high incidence of CMV infection following SCT. This is a retrospective analysis of patients who underwent allogeneic SCT between January 2008 and December 2012 at our centre. 475 patients underwent allogeneic SCT for malignant (46.5%) and non-malignant (53.5%) haematological disorders. 463 (97.4%) SCT recipients and 403 (84.8%) SCT donors were IgG seropositive for CMV. CMV reactivation within 100 days post SCT was seen in 174 (36.6%) at a median of 41 days (range 10-100) post SCT. Ganciclovir was used in 166 patients (95.4%) for a mean duration of 16 days (range 5-32). 157 patients (90%) responded to therapy. Sixty-six patients (42.3%) had secondary reactivation of the virus. Use of a male donor (p = 0.000), donor and recipient age > 15 (p = 0.005 and 0.000), unrelated donor (p = 0.000), degree of HLA mismatch (p = 0.000), occurrence of acute GVHD (p = 0.000) and steroid refractory acute GVHD (p = 0.026) were identified as risk factors for CMV reactivation while early neutrophil recovery (< 15 days) was found to be protective (p = 0.004). On multivariate analysis, male donor (p = 0.042), degree of HLA mismatch (p = 0.006), the occurrence of acute GVHD (p = 0.000) and steroid refractory acute GVHD (p = 0.031) continued to remain significant. 5-year overall survival was significantly better in patients without CMV reactivation compared to those who developed reactivation of CMV (68.9 ± 3.7 vs 58.2 ± 4.9% p = 0.004). The incidence of CMV infection does not seem to be higher despite a high sero-prevalence of CMV. However, patients who developed CMV infection post SCT had inferior outcomes.

A Randomized, Double-Blind, Placebo-Controlled Phase 3 Trial of Oral Brincidofovir for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) infection is a common complication of allogeneic hematopoietic cell transplantation (HCT). In this trial, we randomized adult CMV-seropositive HCT recipients without CMV viremia at screening 2:1 to receive brincidofovir or placebo until week 14 post-HCT. Randomization was stratified by center and risk of CMV infection. Patients were assessed weekly through week 15 and every third week thereafter through week 24 post-HCT. Patients who developed clinically significant CMV infection (CS-CMVi; CMV viremia requiring preemptive therapy or CMV disease) discontinued the study drug and began anti-CMV treatment. The primary endpoint was the proportion of patients with CS-CMVi through week 24 post-HCT; patients who discontinued the trial or with missing data were imputed as primary endpoint events. Between August 2013 and June 2015, 452 patients were randomized at a median of 15 days after HCT and received study drug. The proportion of patients who developed CS-CMVi or were imputed as having a primary endpoint event through week 24 was similar between brincidofovir-treated patients and placebo recipients (155 of 303 [51.2%] versus 78 of 149 [52.3%]; odds ratio, .95 [95% confidence interval, .64 to 1.41]; P = .805); fewer brincidofovir recipients developed CMV viremia through week 14 compared with placebo recipients (41.6%; P < .001). Serious adverse events were more frequent among brincidofovir recipients (57.1% versus 37.6%), driven by acute graft-versus-host disease (32.3% versus 6.0%) and diarrhea (6.9% versus 2.7%). Week 24 all-cause mortality was 15.5% among brincidofovir recipients and 10.1% among placebo recipients. Brincidofovir did not reduce CS-CMVi by week 24 post-HCT and was associated with gastrointestinal toxicity.

Diagnostic efficacy of real-time PCR for ocular cytomegalovirus infections

PURPOSE

The aim of this study is to determine the efficacy of quantitative real-time PCR (qPCR) and clinical characteristics to diagnose ocular cytomegalovirus (CMV) infections.

METHODS

The technical factors were assessed by the outcomes of the qPCR assay at five institutions in Japan using the WHO International Standard of cytomegalovirus. The clinical factors were assessed by examining the aqueous humor samples of 197 eyes of 197 consecutive patients suspected of CMV using the receiver operating characteristics (ROCs).

RESULTS

All of the institutions had excellent detection efficacy, although the copy number ranged from 0.82 to 4.66 copies/IU. In the clinical samples, CMV was detected in 51 eyes, and the amount of CMV DNA was significantly higher for CMV retinitis. In corneal diseases, the amount of CMV DNA was significantly associated with frequency of recurrences and IOP elevations. The sensitivity and specificity of qPCR for the diagnosis was 90.0 and 98.7%, respectively. For the corneal and anterior uveitis types of CMV diseases, the area under the curve (AUC) of qPCR was 0.95 and 0.96, followed by frequency of recurrences with AUC of 0.89 and 0.82, and IOP elevations with AUC of 0.78 and 0.76. Unclassified cytomegalovirus detection, which did not meet diagnostic criteria of CMV corneal endotheliitis, anterior uveitis, or retinitis, was 4.6%, and it was significantly associated with corneal diseases and history of corneal transplantation.

CONCLUSIONS

qPCR with standardization is specific and accurate; however, the inclusion and knowledge of the clinical characteristics improve the diagnostic efficacy.

Cytomegalovirus reactivation and disease amongst patients with allogeneic haematopoietic stem cell transplantation in Eastern India: Epidemiology, outcome and healthcare cost

Purpose

Data from developing countries about incidence, prognosis and healthcare cost of cytomegalovirus (CMV) reactivation amongst patients with allogeneic hematopoietic stem cell transplantation (AHSCT) remain scarce. The purpose of the study was to describe the epidemiology, outcome and cost implications of CMV reactivation and CMV disease amongst patients with AHSCT in cancer hospital in Eastern India.

Materials and Methods

The study design was a retrospective audit of clinical records.

Results

Ninety-nine per cent of patients and 94% of the donors were found to be CMV seropositive. CMV reactivation rate was 43.8% amongst patients with AHSCT (n = 130 patients). CMV reactivation occurred 118 days after AHSCT (median; range: 28-943 days). Patients with any grade of graft-versus-host disease (GVHD) had higher CMV reactivation rate than patients without GVHD. Patients with CMV reactivation had more frequent GVHD than patients without CMV reactivation. Use of steroids was associated with CMV reactivation. We found no differences in overall survival of patients with or without CMV reactivation. The cost of in-house CMV-polymerase chain reaction at our centre was USD $57 (Rs. 3650), cost for intravenous ganciclovir was USD $26 (Rs. 1665) per infusion and oral valganciclovir USD $8 (Rs. 512)/900 mg tablet. The median duration of anti-CMV therapy was 14 days (interquartile range: 14-28 days) and the average cost per patient per month directed towards CMV management ranged between USD $800 and USD $1,300 (Rs. 51,238-Rs. 83,264). Three patients (2.3%) in this series had CMV disease, all of whom died.

Conclusion

In an increasingly globalised world, where medical tourism is common, data from developing countries regarding cost and outcome of CMV infections in AHSCT patients are of relevance.

In-patient outcomes of Hematopoietic Stem Cell Transplantation in Patients with Immune Mediated Inflammatory Diseases: A Nationwide Study

The impact of underlying immune-mediated inflammatory diseases (IMID) in patients undergoing hematopoietic stem cell transplant (HSCT) is unclear. Hematopoietic cell transplantation co-morbidity index (HCT-CI) is gaining acceptance as a reliable clinical method to score pre-transplant co-morbidities. Higher HCT-CI from a co-morbid IMID implies higher NRM. However, HCT-CI integrates many IMIDs with different pathogenesis and treatment together which may lead to spurious results. We performed a cross-sectional study using Nationwide Inpatient Sample dataset from 1998 to 2011 to compare the outcomes of HSCT in patients with different co-morbid IMIDs with patients without any co-morbid IMIDs. In both our multivariate and stringent matched-pair analysis, ulcerative colitis (UC) was associated with increased mortality while rheumatoid arthritis and psoriasis were associated with lower mortality as compared to no IMID group. Furthermore, in allogeneic HSCT subgroup, UC was associated with higher mortality and psoriasis was associated with lower mortality. In conclusion, we found that depending on the type of HSCT, each IMID has a different impact on outcomes of HSCT. Furthermore, UC patients had increased mortality if they had primary sclerosing cholangitis and had a higher risk of opportunistic infections like tuberculosis and cytomegalovirus suggesting the need for increased vigilance in this cohort.

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.

Systemic Virus Infections Differentially Modulate Cell Cycle State and Functionality of Long-Term Hematopoietic Stem Cells In Vivo

Quiescent long-term hematopoietic stem cells (LT-HSCs) are efficiently activated by type I interferon (IFN-I). However, this effect remains poorly investigated in the context of IFN-I-inducing virus infections. Here we report that both vesicular stomatitis virus (VSV) and murine cytomegalovirus (MCMV) infection induce LT-HSC activation that substantially differs from the effects triggered upon injection of synthetic IFN-I-inducing agents. In both infections, inflammatory responses had to exceed local thresholds within the bone marrow to confer LT-HSC cell cycle entry, and IFN-I receptor triggering was not critical for this activation. After resolution of acute MCMV infection, LT-HSCs returned to phenotypic quiescence. However, non-acute MCMV infection induced a sustained inflammatory milieu within the bone marrow that was associated with long-lasting impairment of LT-HSC function. In conclusion, our results show that systemic virus infections fundamentally affect LT-HSCs and that also non-acute inflammatory stimuli in bone marrow donors can affect the reconstitution potential of bone marrow transplants.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

Background

Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome.

Objective

To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center.

Results

Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality.

Conclusions

In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Cytomegalovirus Infection of Endocrine System in a Patient with Diffuse Large B-cell Lymphoma. Report of a Case

Cytomegalovirus (CMV) is an opportunistic pathogen causing different diseases in immunocompromised patients and leading to death in a high percentage of cases. CMV infection is also relatively frequent among patients with hematological malignancies, especially when treated with immunosuppressive agents. We describe the clinical history of a patient with stage IV diffuse large B-cell lymphoma (DLBCL) treated with eight courses of R-CHOP every two weeks, who presented clinical remission of the disease at the end of therapy. However, two months later he developed neurological symptoms due to cerebellar involvement and a subcutaneous dorsal lymphomatous infiltration. He had a partial response after chemotherapy and brain radiotherapy, but his clinical course was complicated by fever and hypotension. Although the fever resolved with broad-spectrum antibiotics, he presented progressive endocrine failure and died three weeks later. Autopsy confirmed disseminated multiorgan involvement by DLBCL associated with an unexpected CMV infection of the lungs and several endocrine organs including the pituitary gland, pancreatic islets and adrenals, a clinical association not previously reported in the English literature.

The potential association of CMV-specific CD8+ T lymphocyte reconstitution with the risk of CMV reactivation and persistency in post allogeneic stem cell transplant patients

OBJECTIVES

development of cytomegalovirus (CMV)-specific CD8+ T cell response is crucial in preventing symptomatic CMV infection specially, in stem cell transplant (SCT) patients. The aim of this study was to evaluate CMV-specific CD8+ T cell reconstitution in allogeneic SCT recipients and to study the possible association between CMV-specific CD8+ T cell recovery with protection from CMV reactivation and persistency.

METHODS

Human leuKocyte antigen (HLA)-tetramers were used for CMV-specific CD8+ cell quantitation by Flow cytometry in twenty post-allogeneic SCT patients.

RESULTS

Nine patients (45%) developed rapid recovery of CMV-specific CD8+ cells, among them; 7 patients (78%) had no CMV reactivation in the first 95 days post-transplant. Five patients had developed persistent CMV viremia; all of them had not developed CMV-specific CD8+ recovery till day 95 post-transplant. Patients with persistent CMV viremia had a statistically significant lower means of CMV-specific CD8+ percent and absolute count compared to those without persistent viremia (p = .001, .015), respectively.

DISCUSSION

The incidence of CMV reactivation and persistency was higher among patients with delayed CMV-specific CD8+ reconstitution in the first 95 days post-transplant.

CONCLUSION

CMV-specific CD8+ cells can help in categorizing patients into risk groups: (early recovery/low risk) and (delayed recovery/increased risk), this tool may guide clinicians in the selection of patients who may profit from prophylactic antiviral therapy and frequent viral monitoring.

Economic burden of preemptive treatment of CMV infection after allogeneic stem cell transplantation: a retrospective study of 208 consecutive patients

BACKGROUND

Cytomegalovirus (CMV) infection and disease (CMV episodes) are global concerns after allogeneic hematopoietic stem cell transplantation (HSCT). They affect survival, both by direct and indirect effects. Due to safety issues of current anti-CMV antivirals, long-term CMV prophylaxis is poorly tolerated and the most common strategy to decrease the incidence of CMV disease is preemptive. New, less toxic, molecules are currently being assessed for CMV prophylaxis which should replace or considerably decrease the preemptive approach. The aim of this study was to assess the economic burden of CMV episodes after HSCT with a preemptive approach.

METHODS

We analyzed data from 208 consecutive adults transplanted in our institution, between 2008 and 2013. Hospital resource utilization was retrieved via the linked hospital admissions and Diagnostic Related Groups for the period of conditioning to 12 months after transplant.

RESULTS

CMV episodes occurred in 70 patients (34%) over the first 12 months following HSCT, after a mean of 75 days (median: 46 (7-334)). The mean total length of stay was significantly associated with the occurrence of a CMV episode (113.9 vs. 87.5 days, p = 0.0002) but was associated neither with the pre-transplant CMV serology of donors/recipients nor with survival. The mean cost of transplant was €104,016 (SD = €37,281) after 12 months. Bivariate and multivariate analyses indicated that the occurrence of >1 CMV episode increased the costs of allogeneic HSCT by 25-30% (p < 0.0001).

CONCLUSION

Our study, which is the largest, single-institution cost study of allogeneic HSCT in Europe, shows that two or more CMV episodes significantly increased the transplant cost. New prophylactic strategies to prevent CMV infection and disease should decrease transplant costs.

Prevention of Cytomegalovirus Reactivation in Haploidentical Stem Cell Transplantation

Cytomegalovirus (CMV) infection can increase the morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Because of a higher degree of immunosuppression, haploidentical transplant recipients may be at an increased risk of viral infections, particularly CMV. We retrospectively analyzed 86 haploidentical HCT recipients at our institution to determine whether a more intensified antiviral strategy would reduce the incidence of CMV reactivation compared with a traditional antiviral prophylaxis regimen. According to practice changes over time in antiviral prophylaxis at our institution, patients were divided into the following 3 groups: hybrid (n = 15), traditional (n = 26), and intermediate dose (n = 45). The hybrid group received valganciclovir from admission to day -2 followed by standard-dose valacyclovir. The traditional group received standard-dose valacyclovir starting on day -1. The intermediate-dose group received ganciclovir from admission through day -2, followed by intermediate-dose valacyclovir. The hybrid and intermediate-dose groups were combined into an intensified group for further analysis. We found the cumulative incidence (CI) of CMV reactivation within 100 days post-HCT was higher for patients receiving the traditional strategy compared with the hybrid and intermediate-dose strategy groups (81% versus 53% versus 71%, respectively; P = .08) and was significantly higher when the traditional group was compared against the intensified group (81% versus 67%, respectively; P = .032). Median time to CMV reactivation was also shorter in the traditional group versus the intensified group (31 versus 41 days, respectively). Moreover, the CI of CMV disease by day 100 was significantly worse for patients receiving the traditional prophylaxis strategy among the 3 groups (8% traditional versus 0% hybrid versus 0% intermediate dose; P = .032). Renal toxicity did not differ between the traditional and intensified group. In conclusion, an intensified approach to prevention of CMV reactivation was associated with lower incidence of CMV reactivation and less CMV disease without increased toxicity. Because the most benefit was observed in the intensified group, further studies are needed to assess which antiviral intervention is the most beneficial on lowering the rates of CMV viremia and disease.

Current and future options for cytomegalovirus reactivation in hematopoietic cell transplantation patients

Report from the 43rd Annual Meeting of the European Society for Blood & Marrow Transplantation 2017, 26-29 March 2017, Marseille, France Cytomegalovirus (CMV) reactivation is a potentially life-threatening complication in immunocompromised recipients of hematopoietic cell transplantation (HCT). Its management was therefore a key topic for over 5000 delegates from 85 countries attending the 43rd Annual Meeting of the European Society for Blood & Marrow Transplantation 2017. The currently available anti-CMV armamentarium is seldom used to prevent CMV reactivation due to the associated myelosuppression and renal toxicity. Following HCT, CMV reactivation is generally managed pre-emptively using sensitive assays for early detection of viral DNA (and to a lesser extent antigenemia) and, where necessary, treatment with antiviral drugs with the aim of preventing CMV disease. However, any degree of CMV reactivation increases the risk of mortality, and novel antiviral therapies may offer the possibility of prophylaxis to prevent CMV reactivation and improve survival after HCT.

Strategies to control human cytomegalovirus infection in adult hematopoietic stem cell transplant recipients

Human cytomegalovirus (HCMV) represents the major viral complication after hematopoietic stem cell transplantation. HCMV infection may be controlled by the reconstituting immune system and remain subclinical or can lead to severe systemic and/or organ disease (mainly pneumonia and gastroenteritis) when immune reconstitution is delayed or impaired. In order to prevent the occurrence of HCMV disease, a prompt diagnosis of HCMV infection is mandatory. The adoption of pre-emptive therapy strategies guided by virological monitoring dramatically reduced the occurrence of HCMV disease. However, late-onset end-organ disease may occur in some patients with apparent immune reconstitution. In the near future, introduction of immunological monitoring and immunotherapies could markedly improve management of HCMV infection.

Cytomegalovirus

Cytomegalovirus (CMV), the largest of the herpesviruses, causes a wide range of clinical syndromes, from asymptomatic infection to severe disease in immunocompromised hosts. Laboratory methods for diagnosis include molecular testing, antigenemia, culture, serology, and histopathology. Treatment of CMV infection and disease is indicated in selected immunocompromised hosts, and preventive approaches are indicated in high-risk groups. This chapter reviews the epidemiology, clinical aspects, and the laboratory diagnosis and management of CMV in immunocompromised hosts.

Cytomegalovirus Treatment in Pediatric Hematopoietic Stem Cell Transplant Patients

Cytomegalovirus (CMV) is a frequent complication of hematopoietic stem cell transplant in pediatric patients, with significant morbidity and mortality. Antiviral drugs are used as prophylactic, preemptive or therapeutic medicines; however, no uniform guidelines exist for the best strategy to prevent CMV disease. Resistance to standard antiviral therapies can lead to further difficulty in managing CMV disease. Studies for investigational therapies are underway and could provide options for treatment of resistant CMV, while limiting toxicities associated with currently used antiviral therapies.

Targeting the latent cytomegalovirus reservoir with an antiviral fusion toxin protein

Reactivation of human cytomegalovirus (HCMV) in transplant recipients can cause life-threatening disease. Consequently, for transplant recipients, killing latently infected cells could have far-reaching clinical benefits. In vivo, myeloid cells and their progenitors are an important site of HCMV latency, and one viral gene expressed by latently infected myeloid cells is US28. This viral gene encodes a cell surface G protein-coupled receptor (GPCR) that binds chemokines, triggering its endocytosis. We show that the expression of US28 on the surface of latently infected cells allows monocytes and their progenitor CD34+ cells to be targeted and killed by F49A-FTP, a highly specific fusion toxin protein that binds this viral GPCR. As expected, this specific targeting of latently infected cells by F49A-FTP also robustly reduces virus reactivation in vitro. Consequently, such specific fusion toxin proteins could form the basis of a therapeutic strategy for eliminating latently infected cells before haematopoietic stem cell transplantation.

Safety of ASP0113, a cytomegalovirus DNA vaccine, in recipients undergoing allogeneic hematopoietic cell transplantation: an open-label phase 2 trial

Cytomegalovirus (CMV) infection/reactivation is a serious complication after hematopoietic cell transplantation (HCT). The DNA vaccine ASP0113 contains two plasmids encoding CMV antigens (glycoprotein B and tegument phosphoprotein 65) that stimulate humoral and cellular immunity. Between June 2013 and February 2014, Astellas conducted a phase 2, open-label, uncontrolled, three-center trial to investigate the safety and tolerability of ASP0113 in Japanese patients undergoing HCT for hematologic disorders. Ten patients aged 22-61 years were enrolled; nine received at least one dose of ASP0113. Six patients received all five doses of ASP0113 5 mg at intervals before and after HCT. Pre-emptive antiviral therapy was allowed. One patient died following relapse of primary disease. All patients had serious adverse events deemed unrelated to ASP0113. CMV viremia (assessed by CMV antigenemia) occurred in seven patients, who then received anti-CMV therapy. No patients developed CMV end-organ disease. Adverse events associated with ASP0113 injection included pyrexia (three patients), skin reactions [injection site pain, injection site tenderness, and erythema (two patients each); and rash, injection site erythema, injection site induration, and injection site swelling (one patient each)], and hyperuricemia (one patient). ASP0113 was well tolerated in Japanese HCT recipients. Further studies should evaluate its efficacy and safety. ClinicalTrials.gov Identifier: NCT01903928.

Comparative Analysis of Clinical-Scale IFN-γ-Positive T-Cell Enrichment Using Partially and Fully Integrated Platforms

Background and aims

The infusion of enriched CMV-specific donor T-cells appears to be a suitable alternative for the treatment of drug-resistant CMV reactivation or de novo infection after both solid organ and hematopoietic stem cell transplantation. Antiviral lymphocytes can be selected from apheresis products using the CliniMACS Cytokine-Capture-System^® either with the well-established CliniMACS^® Plus (Plus) device or with its more versatile successor CliniMACS Prodigy^® (Prodigy).

Methods

Manufacturing of CMV-specific T-cells was carried out with the Prodigy and Plus in parallel starting with 0.8–1 × 10⁹ leukocytes collected by lymphapheresis (n = 3) and using the MACS GMP PepTivator^® HCMVpp65 for antigenic restimulation. Target and non-target cells were quantified by a newly developed single-platform assessment and gating strategy using positive (CD3/CD4/CD8/CD45/IFN-γ), negative (CD14/CD19/CD56), and dead cell (7-AAD) discriminators.

Results

Both devices produced largely similar results for target cell viabilities: 37.2–52.2% (Prodigy) vs. 51.1–62.1% (Plus) CD45⁺/7-AAD⁻ cells. Absolute numbers of isolated target cells were 0.1–3.8 × 10⁶ viable IFN-γ⁺ CD3⁺ T-cells. The corresponding proportions of IFN-γ⁺ CD3⁺ T-cells ranged between 19.2 and 95.1% among total CD3⁺ T-cells and represented recoveries of 41.9–87.6%. Within two parallel processes, predominantly IFN-γ⁺ CD3⁺CD8⁺ cytotoxic T-cells were enriched compared to one process that yielded a higher amount of IFN-γ⁺ CD3⁺CD4⁺ helper T lymphocytes. T-cell purity was higher for the Prodigies products that displayed a lower content of contaminating IFN-γ⁻ T-cells (3.6–20.8%) compared to the Plus products (19.9–80.0%).

Conclusion

The manufacturing process on the Prodigy saved both process and hands-on time due to its higher process integration and ability for unattended operation. Although the usage of both instruments yielded comparable results, the lower content of residual IFN-γ⁻ T-cells in the target fractions produced with the Prodigy may allow for a higher dosage of CMV-specific donor T-cells without increasing the risk for graft-versus-host disease.

Assessment of a cytomegalovirus serology dual-testing strategy in hematopoietic stem cell transplant recipients

BACKGROUND

Accurate determination of recipient cytomegalovirus (CMV) serostatus before allogeneic hematopoietic stem cell transplantation (HSCT) is critical, as it is the most important predictor of post-transplant CMV infection and remains associated with non-relapse mortality. The purpose of this study was to assess a recipient dual-testing strategy before HSCT.

METHODS

CMV serologic testing was performed before allogeneic HSCT using 2 different assays: reference laboratory (RL) and American Red Cross (ARC). In all cases, blood samples were obtained for RL testing either before ARC testing (median 130 days before HSCT [range 12-2594]) or at the same time (median 25 days before HSCT [range 8-129]). The results of serologic testing were correlated with CMV viremia post HSCT.

RESULTS

Of 287 recipients evaluated, 76 (26.5%) had discordant results, of which 74 (97.4%) tested RL-/ARC+. Ten had RL and ARC testing performed on simultaneously obtained samples, 3 of which (30%) were discordant (3 [100%] RL-/ARC+). Acute myeloid leukemia and receipt of blood product transfusion in the interval between testing were associated with RL-/ARC+ discordance. Correlation with viremia after HSCT suggested that RL-/ARC+ discordance was caused by detection of anti-CMV immunoglobulin transferred in transfused blood products and reduced specificity of the ARC assay.

CONCLUSION

CMV-seronegative hematopoietic stem cell transplant recipients may be misclassified as seropositive if testing is performed after receipt of blood products or when using assays optimized for sensitivity at the expense of specificity. This misclassification may negatively affect post-HSCT outcomes for individual patients and studies that rely on accurate CMV serology reporting.

Infectious diseases in allogeneic haematopoietic stem cell transplantation: prevention and prophylaxis strategy guidelines 2016

Infectious complications after allogeneic haematopoietic stem cell transplantation (allo-HCT) remain a clinical challenge. This is a guideline provided by the AGIHO (Infectious Diseases Working Group) of the DGHO (German Society for Hematology and Medical Oncology). A core group of experts prepared a preliminary guideline, which was discussed, reviewed, and approved by the entire working group. The guideline provides clinical recommendations for the preventive management including prophylactic treatment of viral, bacterial, parasitic, and fungal diseases. The guideline focuses on antimicrobial agents but includes recommendations on the use of vaccinations. This is the updated version of the AGHIO guideline in the field of allogeneic haematopoietic stem cell transplantation utilizing methods according to evidence-based medicine criteria.

Early CMV-replication after allogeneic stem cell transplantation is associated with a reduced relapse risk in lymphoma

A preventive effect of early human cytomegalovirus (HCMV) replication was evaluated in 136 non-Hodgkin lymphoma (NHL) patients with mature B-cell NHLs (n = 94), and mature T- and NK-cell NHLs (n = 42) after allogeneic stem cell transplantation (alloSCT). Most study-patients (85%) had received at least 2 cycles of chemotherapy and 60% had also received an autograft prior to alloSCT. First detection of CMV-replication by HCMV antigenemia/viremia was found at a median of day +33 after alloSCT. The cumulative incidence of relapse at 5 years after alloSCT was 38% (95% confidence interval [95%CI]: 26-49) in 82 patients without compared to 22% (95%CI: 8-37) in 54 patients with HCMV antigenemia/viremia (p = .013). A decreased relapse risk of HCMV replication was confirmed by multivariate analysis for HCMV antigenemia/viremia (Hazard ratio [HR]: 0.29, 95%CI: 0.11-0.76, p < .014). This report demonstrated a possible improvement of relapse incidence after replicative HCMV infection in patients with NHL after alloSCT.

CMV-specific immune reconstitution following allogeneic stem cell transplantation

Cytomegalovirus (CMV) remains a major contributor to morbidity and mortality following allogeneic haemopoietic stem cell transplant (HSCT) despite widespread use of viraemia monitoring and pre-emptive antiviral therapy. Uncontrolled viral replication occurs primarily in the first 100 d post transplant but this high risk period can extend to many months if immune recovery is delayed. The re-establishment of a functional population of cellular effectors is essential for control of virus replication and depends on recipient and donor serostatus, the stem cell source, degree of HLA matching and post-transplant factors such as CMV antigen exposure, presence of GVHD and ongoing use of immune suppression. A number of immune monitoring assays exist but have not yet become widely accessible for routine clinical use. Vaccination, adoptive transfer of CMV specific T cells and a number of graft engineering processes are being evaluated to enhance of CMV specific immune recovery post HSCT.