Management of CMV, HHV-6, HHV-7 and Kaposi-sarcoma herpesvirus (HHV-8) infections in patients with hematological malignancies and after SCT. Bone Marrow Transplant. 2008;42:227-240. [PMID: 18587440 DOI: 10.1038/bmt.2008.162]

Human herpesvirus-6, HHV-8 and parvovirus B19 after allogeneic hematopoietic cell transplant: the lesser-known viral complications

PURPOSE OF REVIEW

Viral infections continue to burden allogeneic hematopoietic cell transplant (HCT) recipients. We review the epidemiology, diagnosis, and management of human herpesvirus (HHV)-6, HHV-8 and parvovirus B19 following HCT.

RECENT FINDINGS

Advances in HCT practices significantly improved outcomes but impact viral epidemiology: post-transplant cyclophosphamide for graft-versus-host disease prevention increases HHV-6 reactivation risk while the impact of letermovir for CMV prophylaxis - and resulting decrease in broad-spectrum antivirals - is more complex. Beyond the well established HHV-6 encephalitis, recent evidence implicates HHV-6 in pneumonitis. Novel less toxic therapeutic approaches (brincidofovir, virus-specific T-cells) may enable preventive strategies in the future. HHV-8 is the causal agent of Kaposi's sarcoma, which is only sporadically reported after HCT, but other manifestations are possible and not well elucidated. Parvovirus B19 can cause severe disease post-HCT, frequently manifesting with anemia, but can also be easily overlooked due to lack of routine screening and ambiguity of manifestations.

SUMMARY

Studies should establish the contemporary epidemiology of HHV-6, and other more insidious viruses, such as HHV-8 and parvovirus B19 following HCT and should encompass novel cellular therapies. Standardized and readily available diagnostic methods are key to elucidate epidemiology and optimize preventive and therapeutic strategies to mitigate the burden of infection.

Human Herpes Virus-6 (HHV-6) Reactivation after Hematopoietic Cell Transplant and Chimeric Antigen Receptor (CAR)- T Cell Therapy: A Shifting Landscape

HHV-6B reactivation affects approximately half of all allogeneic hematopoietic cell transplant (HCT) recipients. HHV-6B is the most frequent infectious cause of encephalitis following HCT and is associated with pleiotropic manifestations in this setting, including graft-versus-host disease, myelosuppression, pneumonitis, and CMV reactivation, although the causal link is not always clear. When the virus inserts its genome in chromosomes of germ cells, the chromosomally integrated form (ciHHV6) is inherited by offspring. The condition of ciHHV6 is characterized by the persistent detection of HHV-6 DNA, often confounding diagnosis of reactivation and disease-this has also been associated with adverse outcomes. Recent changes in clinical practice in the field of cellular therapies, including a wider use of post-HCT cyclophosphamide, the advent of letermovir for CMV prophylaxis, and the rapid expansion of novel cellular therapies require contemporary epidemiological studies to determine the pathogenic role and spectrum of disease of HHV-6B in the current era. Research into the epidemiology and clinical significance of HHV-6B in chimeric antigen receptor T cell (CAR-T cell) therapy recipients is in its infancy. No controlled trials have determined the optimal treatment for HHV-6B. Treatment is reserved for end-organ disease, and the choice of antiviral agent is influenced by expected toxicities. Virus-specific T cells may provide a novel, less toxic therapeutic modality but is more logistically challenging. Preventive strategies are hindered by the high toxicity of current antivirals. Ongoing study is needed to keep up with the evolving epidemiology and impact of HHV-6 in diverse and expanding immunocompromised patient populations.

Advances and Challenges in Cytomegalovirus Detection Methods for Liver Transplant Donors

Cytomegalovirus (CMV) infection is a highly prevalent opportunistic infection among liver transplant recipients. When the liver donor is infected with CMV, there is a risk of transmission to the recipient, leading to CMV infection. To improve the postoperative outcome of liver transplantation, it is crucial to shift the focus of CMV detection to the donor and achieve early diagnosis, as well as implement effective preventative and therapeutic measures. However, the commonly used CMV detection methods in the past had limitations that prevented their early and accurate diagnosis in liver transplant donors. This review focuses on the latest advancements in CMV detection methods that can potentially be applied to liver transplant donors. The objective is to compare and evaluate their clinical utility, thereby providing guidance and support for rapid and accurate diagnosis of CMV infection in the clinic. The clustered regularly interspaced short palindromic repeats-associated proteins (CRISPR-Cas) system-based assay emerges as a promising method for detecting the virus, offering great prospects for early and expedient CMV infection diagnosis in clinical settings.

Recent Updates on Viral Oncogenesis: Available Preventive and Therapeutic Entities

Human viral oncogenesis is a complex phenomenon and a major contributor to the global cancer burden. Several recent findings revealed cellular and molecular pathways that promote the development and initiation of malignancy when viruses cause an infection. Even, antiviral treatment has become an approach to eliminate the viral infections and prevent the activation of oncogenesis. Therefore, for a better understanding, the molecular pathogenesis of various oncogenic viruses like, hepatitis virus, human immunodeficiency viral (HIV), human papillomavirus (HPV), herpes simplex virus (HSV), and Epstein-Barr virus (EBV), could be explored, especially, to expand many potent antivirals that may escalate the apoptosis of infected malignant cells while sparing normal and healthy ones. Moreover, contemporary therapies, such as engineered antibodies antiviral agents targeting signaling pathways and cell biomarkers, could inhibit viral oncogenesis. This review elaborates the recent advancements in both natural and synthetic antivirals to control viral oncogenesis. The study also highlights the challenges and future perspectives of using antivirals in viral oncogenesis.

Cytomegalovirus enteritis resistant to antiviral drugs improved following total colectomy

BACKGROUND

Cytomegalovirus (CMV) infection, often subclinical in childhood, is reactivated during a state of cell-mediated immunodeficiency. In cases of organ damage, patients can require medical treatment for an infectious disease, generally through the use of antiviral drugs. There are no reports of surgical treatment in cases, where infection was found, and medical treatment was difficult. We encountered a case of CMV enteritis that was difficult to treat because of resistance to antivirals but improved after total colectomy.

CASE PRESENTATION

A previously healthy, 74-year-old woman visited a doctor with a chief complaint of watery diarrhea persisting for 2 weeks; she was transferred to our hospital because of hypoxemia and hypovolemic shock. Computed tomography scan indicated wall thickening over the entire colon and the patient was diagnosed with infectious colitis. Conservative and antibacterial therapies were started with fasting fluid replacement. Subsequently, bloody stools were observed 11 days after admission. Colonoscopy was then performed, which showed mucosal edema and longitudinal ulcer, while a histopathological examination of the colon mucosa revealed C7HRP positive on 22 days after admission. CMV enteritis was diagnosed, and the antiviral medication, ganciclovir, was started. Diseases causing immunosuppression and other possible causes of enteritis were also closely examined; however, all were negative. Furthermore, the patient's symptoms and her endoscopic findings did not improve with ganciclovir administration; therefore, the antiviral drug was changed to foscarnet. Unfortunately, the patient did not improve despite the additional administration of gamma globulin and methylprednisolone, and she was determined to have enteritis resistant to medical therapy. A total colon resection was performed 88 days after the admission. Her condition gradually stabilized postoperatively, and oral intake was initiated and tolerated. The patient was transferred to another hospital for rehabilitation for home discharge. She is now at home and has had no recurrences.

CONCLUSIONS

In previous reports of surgical treatment for CMV enteritis, many cases were initially undiagnosed, emergency surgery was performed after perforation or stenosis was recognized, and then CMV was diagnosed and treated. In CMV enteritis without immunodeficiency, surgical treatment may be an option if medical treatment is ineffective.

Poor graft function after haploidentical stem cell transplantation with post-transplant cyclophosphamide

This is a retrospective cohort study of consecutive adult patients who received a haploidentical-SCT (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) in a single centre. Poor graft function (PGF) was defined as the occurrence of either persistent neutropenia (ANC < 0.5 × 10⁹/µL) with poor response to granulocyte colony-stimulating factors (G-CSF) and/or thrombocytopenia (platelets < 20 × 10⁹/L) with transfusion dependence, with complete donor chimerism and without concurrent severe GVHD or underlying disease relapse, during the first 12 months after transplantation. Forty-four (27.5%) out of 161 patients were diagnosed with PGF. Previous CMV reactivation was significantly more frequent in patients with PGF (88.6% versus 73.5%, p = 0.04) and the number of reactivations was also higher in these patients. Besides, early CMV reactivations in the first 6 months post-SCT were also significantly more frequent among patients with PGF (88.6% versus 71.8% p = 0.025). Thirty-two percent of patients with PGF were treated with increasing doses of thrombopoietin-receptor agonists (TRA) and 7 patients were treated with a donor CD34 + selected boost. In total, 93.2% of patients reached adequate peripheral blood counts in a median time of 101 days (range 11-475) after diagnosis. PGF is a frequent complication after haplo-SCT with PT-Cy. CMV reactivation might be the most relevant factor associated to its development. Even when most patients recover peripheral counts with support therapy, there is a group of patients with persistent cytopenias who can effectively be treated with TRA and/or a boost of CD34 + selective cells.

Distinct Immune Reconstitution Profiles Captured by Immune Functional Assays at 6 Months Post Allogeneic Hematopoietic Stem Cell Transplantation

Immune reconstitution after allogeneic-hematopoietic-stem-cell transplantation (allo-HSCT) is a complex and individual process. In this cross-sectional study, whole-blood (WB) immune functional assay (IFA) was used to characterize immune function by assessing immune-related gene/pathway alterations. The usefulness of this tool in the context of infection, 6 months after transplantation, was evaluated. Sixty allo-HSCT recipients at 6 months after transplantation and 10 healthy volunteers (HV) were included. WB was stimulated in standardized TruCulture tubes using lipopolysaccharides and Staphylococcal enterotoxin B. Gene expression was quantified using a custom 144-gene panel using NanoString nCounter technology and analyzed using Ingenuity Pathway Analysis. The relationships between immune function and clinical characteristics, immune cell counts, and post-transplantation infections were assessed. Allo-HSCT recipients were able to activate similar networks of the innate and adaptive immune response compared to HV, with, nevertheless, a lower intensity. A reduced number and a lower expression of genes associated with immunoregulatory and inflammatory processes were observed in allo-HSCT recipients. The use of immunosuppressive treatments was associated with a protracted immune reconstitution revealed by transcriptomic immunoprofiling. No difference in immune cell counts was observed among patients receiving or not receiving immunosuppressive treatments using a large immunophenotyping panel. Moreover, the expression of a set of genes, including CCL3/CCL4, was significantly lower in patients with Herpesviridae reactivation (32%, 19/60), which once again was not identified using classical immune cell counts. Transcriptional IFA revealed the heterogeneity among allo-HSCT recipients with a reduced immune function, a result that could not be captured by circulating immune cell counts. This highlights the potential added value of this tool for the personalized care of immunocompromised patients.

How to improve the outcomes of elderly acute myeloid leukemia patients through allogeneic hematopoietic stem cell transplantation

In recent years, with the gradual advancement of haploidentical transplantation technology, the availability of donors has increased significantly, along with the widespread use of reduced-intensity conditioning and the improvement of nursing techniques, giving more elderly acute myeloid leukemia (AML) patients the chance to receive allogeneic hematopoietic stem cell transplantation. We have summarized the classic and recently proposed pre-transplant assessment methods and assessed the various sources of donors, conditioning regimens, and post-transplant complication management based on the outcomes of large-scale clinical studies for elderly AML patients.

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

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

Cytomegalovirus lymphadenitis mimicking a relapsed diffuse large B-cell lymphoma

Cytomegalovirus (CMV) reactivation is frequent after autologous stem cell transplantation (ASCT), but generalized CMV lymphadenitis is rare. We report a CMV lymphadenitis after an ASCT mimicking a relapse of a diffuse large B-cell lymphoma. After histopathological documentation, CMV lymphadenitis should be treated to avoid systemic progression.

Human seminal virome: a panel based on recent literature

Background

The seminal virome and its implications for fertility remain poorly understood. To date, there are no defined panels for the detection of viruses of clinical interest in seminal samples.

Results

In this study, we characterized the human seminal virome based on more than 1,000 studies published over the last five years.

Conclusions

The number of studies investigating viruses that occur in human semen has increased, and to date, these studies have been mostly prospective or related to specific clinical findings. Through the joint analysis of all these studies, we have listed the viruses related to the worsening of seminal parameters and propose a new panel with the main viruses already described that possibly affect male fertility and health. This panel can assist in evaluating semen quality and serve as a tool for investigation in cases of infertility.

Effect of sorafenib maintenance on Epstein-Barr virus and cytomegalovirus infections in patients with FLT3-ITD AML undergoing allogeneic hematopoietic stem cell transplantation: a secondary analysis of a randomized clinical trial

BACKGROUND

Use of kinase inhibitors such as dasatinib and imatinib might increase the risk of opportunistic infections, especially Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections. However, the effect of sorafenib on EBV and CMV infections remains unclear. The aim of this study was to investigate the effect of sorafenib maintenance post-transplantation on the incidence and mortality of EBV and CMV infections in patients with FLT3-ITD acute myeloid leukemia.

METHODS

This was a follow-up of our randomized controlled trial undertaken at seven hospitals in China. The primary endpoint was EBV and CMV infections within 3 years post-transplantation. Secondary endpoints included the cumulative incidences of relapse, non-relapse mortality (NRM), overall survival (OS), leukemia-free survival (LFS), and graft-versus-host disease (GVHD)-free/relapse-free survival (GRFS) at 3 years.

RESULTS

Two hundred two patients were assigned to sorafenib maintenance (n=100) or non-maintenance (control, n=102). Median extended follow-up post-transplantation was 36.8 (range, 2.5-67.1) months. The 3-year cumulative incidences of EBV-DNAemia and EBV-associated diseases were 24.0% (95% CI: 16.1-32.8%) and 5.0% (1.8-10.6%) in the sorafenib group, and 24.5% (16.6-33.2%) and 5.9% (2.4-11.6%) in the control group (P=0.937; P=0.771). The 3-year cumulative incidences of CMV-DNAemia and CMV-associated diseases were 56.0% (45.6-65.1%) and 8.0% (3.7-14.4%) in the sorafenib group, and 52.9% (42.7-62.1%) and 8.8% (4.3-15.3%) in the control group (P=0.997; P=0.826). The 3-year cumulative mortality of EBV- and CMV-associated diseases was 0.0% (0.0-0.0%) and 2.0% (0.4-6.4%) in the sorafenib group, and 1.0% (0.1-4.8%) and 2.0% (0.4-6.3%) in the control group (P=0.322, P=0.980). The 3-year cumulative incidences of relapse, NRM, OS, LFS, and GRFS were 13.0%, 11.1%, 79.0%, 75.9%, and 65.8% in the sorafenib group and 34.8%, 12.7%, 61.4%, 52.5%, and 46.6% in the control group, respectively (P<0.001, P=0.656, P=0.005, P<0.001, P=0.003). The reconstitution of T lymphocyte subsets, B lymphocytes, and natural killer cells was similar between the two groups (all P>0.05).

CONCLUSIONS

Sorafenib maintenance post-transplantation does not increase the incidence and mortality of EBV and CMV infections, demonstrating a favorable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02474290 . Registered on June 14, 2015.

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

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

Long-term use of foscarnet is associated with an increased incidence of acute kidney injury in hematopoietic stem cell transplant patients: A retrospective observational study

BACKGROUND

Foscarnet is an important drug for the treatment of cytomegalovirus infection in patients undergoing hematopoietic stem cell transplantation (HSCT). Foscarnet is often discontinued because of the development of acute kidney injury (AKI). Thus, the identification of factors leading to the development of AKI is beneficial. This study aimed to investigate the incidence of AKI and the factors influencing AKI development in HSCT patients treated with foscarnet.

METHODS

This was a retrospective observational study. Patients who underwent HSCT and received foscarnet at the Department of Hematology, Osaka City University Hospital, were identified from medical records. The patients were classified into AKI and non-AKI groups, and the risk factors associated with AKI were evaluated. For continuous variables, receiver-operating characteristic (ROC) curve analysis was used to calculate the optimal cutoff value.

RESULTS

Thirty-five patients (47 cases) were assigned to the AKI (51.1%, 24/47) and non-AKI groups (48.9%, 23/47). The AKI group had a significantly longer foscarnet administration period than the non-AKI group (p = 0.049). The appropriate cutoff value for the foscarnet administration period using ROC curve was 27 days. The incidence of AKI was significantly higher in cases who received foscarnet for more than 27 days (11/14, 78.6%) compared to those who received less than 27 days (13/33, 39.4%) (odds ratio: 5.64, 95% confidence interval 1.32-24.2, p = 0.024).

CONCLUSION

The incidence of AKI was 51.1% in HSCT patients treated with foscarnet, and foscarnet administration for more than 27 days may be associated with the incidence of AKI. This article is protected by copyright. All rights reserved.

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.

Human herpesvirus 8 and Kaposi sarcoma: how should we screen and manage the transplant recipient?

PURPOSE OF REVIEW

HHV-8-associated diseases are rare but potentially fatal in transplant recipients. Important differences exist in the distribution of HHV-8 seroprevalence, which might contribute to the lack of uniform approach to HHV-8. The aim of this review was to discuss recent updates in screening and management of HHV-8 after transplant.

RECENT FINDINGS

Increasing attention has been given to the nonmalignant but potentially fatal inflammatory syndrome caused by HHV-8 in solid organ transplant (SOT) recipients. At-risk groups include HHV-8-IgG D+/R- transplant and HHV-8-positive recipients. Severe cases of donor-derived HHV-8 disease, mainly Kaposi sarcoma, frequently without skin involvement and some diagnosed at autopsy, highlight the need to increase clinicians' awareness, to implement effective preemptive strategies and to perform rapid diagnosis. In HSCT setting, HHV-8-associated disorders are very rare.

SUMMARY

Identification of SOT recipients at risk through reliable serology is warranted and the utility of preemptive management and HHV-8-DNA monitoring should be studied. Clinicians should be aware of severe nonmalignant disorders and of early post-SOT Kaposi sarcoma cases with lymph node or transplanted organ involvement in order to provide prompt diagnosis and treatment. No screening for HHV-8 is warranted after HSCT but rapid diagnosis and reduction of immunosuppression remain fundamental.

Infection risk and prophylaxis in patients with lymphoid cancer

Infections are a common cause of morbidity and mortality in patients with lymphoid cancer. With evolving cancer therapeutics, including new targeted and immunotherapies, clinicians need to be aware of additional risk factors and infections that may arise in patients treated with these agents. This "How I Treat" article will highlight fundamental issues including risk factors for infection, infectious diseases screenings and antimicrobial prophylaxis recommendations in patients with lymphoid cancers. We present 4 scenarios of patients with lymphoid cancers with varied infections and describe a treatment approach based on a combination of evidence-based data and experience, as there are limitations in objective infection data especially with newer agents. The goal of this discussion is to provide a framework for institutions and health care providers to develop their own approach in preventing and treating infections in patients with lymphoid cancer.

Incidence of refractory cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation

Post-transplant cytomegalovirus (CMV) disease can be almost completely avoided by current infection control procedures. However, CMV reactivation occurs in more than half of patients, and some patients can develop clinically resistant CMV infections. Whether resistance is due to the host's immune status or a viral resistance mutation is challenging to confirm. Therefore, a prospective observational analysis of refractory CMV infection was conducted in 199 consecutive patients who received allogeneic hematopoietic stem cell transplantation at a single institution. Among them, 143 (72%) patients received anti-CMV drugs due to CMV reactivation, and only 17 (8.5%) exhibited refractory CMV infection. These patients had clinically refractory infection. However, viral genome analysis revealed that only one patient exhibited a mutation associated with the anti-CMV drug resistance. Clinical resistance was mainly correlated with host immune factors, and the incidence of resistance caused by gene mutations was low at the early stage after a transplantation.

Cytomegalovirus DNAemia and disease: current-era epidemiology, clinical characteristics and outcomes in cancer patients other than allogeneic hematopoietic transplantation

BACKGROUND AND OBJECTIVES

High-intensity chemotherapy and advances in novel immunotherapies have seen the emergence of cytomegalovirus (CMV) infections in cancer patients other than allogeneic haematopoietic cell transplantation (HCT). We therefore aimed to evaluate the epidemiology, clinical characteristics, and outcomes of CMV infection in this population.

METHOD

A retrospective review of cancer patients other than allogeneic HCT who had CMV DNAemia and/or disease from July 2013 till May 2020 at a quaternary cancer center was performed.

RESULTS

Of 11,485 cancer patients who underwent treatment during this period, 953 patients had CMV DNA testing performed and 238 of them had CMV DNAemia. After excluding patients with allogeneic HCT, 62 patients with CMV DNAemia were identified of which 10 had concurrent CMV disease. The most frequent underlying malignancies were B-cell lymphoproliferative disease (LPD) (31%, 19/62), T-cell LPD (21%, 13/62), chronic lymphocytic leukemia (11%, 7/62), and multiple myeloma (10%, 6/62). Most patients had lymphopenia (77%, 48/62), multiple cancer therapies (63%, 39/62 received ≥2 previous therapies), co-infection (56%, 35/62 had ≥1 co-infection) and corticosteroid therapy (48%, 30/62) within one month before CMV diagnosis. CMV DNAemia and disease were observed in patients receiving novel immunotherapies including bispecific antibody therapy, chimeric-antigen receptor T-cell therapy and immune checkpoint inhibitors.

CONCLUSION

Patients with haematological malignancy, particularly B-cell LPD, T-cell LPD, chronic lymphocytic leukemia and multiple myeloma were frequently identified to have CMV DNAemia and disease. Lymphopenia, multiple cancer therapies, co-infection, and recent receipt of systemic corticosteroids were also commonly observed. Future studies are necessary to determine optimal identification and management of CMV in these patients. This article is protected by copyright. All rights reserved.

Relationship between renal dysfunction and electrolyte abnormalities in hematopoietic stem cell transplant patients treated with foscarnet

This study aimed to investigate the relationship between renal dysfunction and electrolyte abnormalities, which are adverse events of foscarnet used for cytomegalovirus infection. Of the Ninety hematopoietic stem cell transplantation patients, 32 who met the selection criteria were enrolled in this retrospective study. The study patients were divided into two groups according to whether they developed renal dysfunction. The incidences of hypocalcemia, hypokalemia, and hypomagnesemia with an increase of grade 2 or higher in the renal dysfunction group were 45.5%, 18.2%, and 27.3%, respectively. Additionally, in the renal dysfunction group, a significant correlation was observed between creatinine and calcium (r = -0.458, p = 0.0244) and between creatinine and potassium (r = -0.520, p = 0.0092). This study shows that renal dysfunction and electrolyte abnormalities may be closely related in HSCT patients receiving foscarnet; thus, it is a report that may contribute to the safety of continuous foscarnet treatment.

Standardized monitoring of cytomegalovirus-specific immunity can improve risk stratification of recurrent cytomegalovirus reactivation after hematopoietic stem cell transplantation

Recurrence of cytomegalovirus reactivation remains a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation. Monitoring cytomegalovirus-specific cellular immunity using a standardized assay might improve the risk stratification of patients. A prospective multicenter study was conducted in 175 intermediate- and high-risk allogeneic hematopoietic stem cell transplant recipients under preemptive antiviral therapy. Cytomegalovirus-specific cellular immunity was measured using a standardized IFN-γ ELISpot assay (T-Track® CMV). Primary aim was to evaluate the suitability of measuring cytomegalovirus-specific immunity after end of treatment for a first cytomegalovirus reactivation to predict recurrent reactivation. 40/101 (39.6%) patients with a first cytomegalovirus reactivation experienced recurrent reactivations, mainly in the high-risk group (cytomegalovirus-seronegative donor/cytomegalovirus-seropositive recipient). The positive predictive value of T-Track® CMV (patients with a negative test after the first reactivation experienced at least one recurrent reactivation) was 84.2% in high-risk patients. Kaplan-Meier analysis revealed a higher probability of recurrent cytomegalovirus reactivation in high-risk patients with a negative test after the first reactivation (hazard ratio 2.73; p=0.007). Interestingly, a post-hoc analysis considering T-Track® CMV measurements at day 100 post-transplantation, a time point highly relevant for outpatient care, showed a positive predictive value of 90.0% in high-risk patients. Our results indicate that standardized cytomegalovirus-specific cellular immunity monitoring may allow improved risk stratification and management of recurrent cytomegalovirus reactivation after hematopoietic stem cell transplantation. This study was registered at www.clinicaltrials.gov as #NCT02156479.

Management of Herpesvirus Infections in Hematopoietic Cell Transplant Recipients

Following primary infection, herpesviruses establish latency in infected individuals in the host cells and may reactivate upon external stimuli and during periods of immunosuppression. The objective of this paper was to the present current strategies on preventive and therapeutic management of infections with herpesviruses in recipients of hematopoietic cell transplantation. Strategies of antiviral management include prophylaxis, pre-emptive treatment and targeted treatment. Empirical therapy is not used in antiviral strategies. Prophylaxis can be done at universal (preventive strategy) and specific level. Universal prophylaxis includes non-pharmacologic methods of prevention of infection or reactivation. Risk-adapted specific prophylaxis includes use of specific antivirals or cellular therapy or other specific methods in order to prevent specific infection, in high-risk groups. Pre-emptive therapy means use of therapeutic approaches in asymptomatic infection, detected by a screening assay. Targeted therapy is used in established specific viral end-organ infections. The following sections of the paper refer to prophylaxis and treatment strategies, respectively, against CMV, EBV, HSV, VZV, HHV-6, HHV-7, and HHV-8 after allogeneic hematopoietic cell transplantation.

Recent Approaches and Strategies in the Generation of Anti-human Cytomegalovirus Vaccines

Human cytomegalovirus is the largest human herpesvirus and shares many core features of other herpesviruses such as tightly regulated gene expression during genome replication and latency as well as the establishment of lifelong persistence following infection. In contrast to stereotypic clinical syndromes associated with alpha-herpesvirus infections, almost all primary HCMV infections are asymptomatic and acquired early in life in most populations in the world. Although asymptomatic in most individuals, HCMV is a major cause of disease in hosts with deficits in adaptive and innate immunity such as infants who are infected in utero and allograft recipients following transplantation. Congenital HCMV is a commonly acquired infection in the developing fetus that can result in a number of neurodevelopmental abnormalities. Similarly, HCMV is a major cause of disease in allograft recipients in the immediate and late posttransplant period and is thought to be a major contributor to chronic allograft rejection. Even though HCMV induces robust innate and adaptive immune responses, it also encodes a vast array of immune evasion functions that are thought aid in its persistence. Immune correlates of protective immunity that prevent or modify intrauterine HCMV infection remain incompletely defined but are thought to consist primarily of adaptive responses in the pregnant mother, thus making congenital HCMV a potentially vaccine modifiable disease. Similarly, HCMV infection in allograft recipients is often more severe in recipients without preexisting adaptive immunity to HCMV. Thus, there has been a considerable effort to modify HCMV specific immunity in transplant recipient either through active immunization or passive transfer of adaptive effector functions. Although efforts to develop an efficacious vaccine and/or passive immunotherapy to limit HCMV disease have been underway for nearly six decades, most have met with limited success at best. In contrast to previous efforts, current HCMV vaccine development has relied on observations of unique properties of HCMV in hopes of reproducing immune responses that at a minimum will be similar to that following natural infection. However, more recent findings have suggested that immunity following naturally acquired HCMV infection may have limited protective activity and almost certainly, is not sterilizing. Such observations suggest that either the induction of natural immunity must be specifically tailored to generate protective activity or alternatively, that providing targeted passive immunity to susceptible populations could be prove to be more efficacious.

Kaposi sarcoma in a child after hematopoietic stem cell transplantation: Should pre-transplant HHV-8 screening be considered in recipients from high prevalence areas?

Kaposi sarcoma (KS) is an angioproliferative disease associated with human herpesvirus 8 (HHV-8). We report the case of a 10-year-old male from a high HHV-8 prevalence area, diagnosed with severe aplastic anemia who underwent an upfront hematopoietic stem cell transplantation (HSCT). Five months after transplant, the patient was diagnosed with KS with skin, mucosae, lymph nodes and lung involvement. After withdrawal of immunosuppression the patient achieved complete remission without requiring further treatments. KS may occur after HSCT in patients from high HHV-8 prevalence areas. Considering that, we propose that screening of HHV-8 by antibody testing could be considered in HSCT donors/recipients from these areas.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Negative Impact of Cytomegalovirus Reactivation on Survival in Adult Patients with Aplastic Anemia after an Allogeneic Hematopoietic Stem Cell Transplantation: A Report from Transplantation-Related Complication and Adult Aplastic Anemia Working Groups of the Japan Society for Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) infection is a major infectious complication following an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Recent large-scale retrospective studies reported that CMV reactivation is an independent risk factor for poor post-transplant outcomes, although the development of CMV end-organ disease is suppressed by the CMV antiviral preemptive therapy, which has been mainly analyzed for hematopoietic malignancies, such as acute leukemia. However, it remains unclear whether CMV reactivation also has a negative effect on post-transplant outcomes in aplastic anemia (AA). Therefore, we evaluated the clinical relevance of CMV reactivation in patients with AA using the registry database of the Japan Society for Hematopoietic Cell Transplantation. Adult patients with AA who underwent their first allo-HSCT between 2005 and 2017 and who survived with neutrophil engraftment until 100 days post-transplantation were analyzed (n = 672). Patients were monitored using pp65 antigenemia since the time of engraftment, and CMV reactivation in the analysis of this study was defined as the beginning of CMV preemptive or definitive therapy within 100 days post-transplantation. CMV reactivation occurred in 372 (55%) patients, including 19 with CMV end-organ disease. In time-dependent multivariate analysis, patients aged ≥40 years (hazard ratio [HR], 1.89; P = .003) who underwent transplantation from HLA-matched related peripheral blood stem cells (HR, 2.85; P = .008), HLA-matched unrelated bone marrow (BM) (HR, 2.01; P = .036), and other stem cell sources (HR, 2.32; P = .007) compared to HLA-matched related BM, CMV reactivation (HR 1.65; P = .042), grade II to IV acute graft-versus-host disease (HR 1.73; P = .013), and secondary graft failure (HR 7.09; P < .001) had independent risk factors that significantly decreased overall survival, indicating that CMV reactivation, one of the early events at post-transplantation, had a significant negative impact on the long-term prognosis at post-transplantation. This effect was more pronounced in patients aged ≥40 years who received a graft from other than HLA-matched related BM. Comparing the causes of death with and without CMV reactivation, no significant difference in the frequency of each cause of death was observed between the 2 groups (P = .453). Improvement of post-transplant CMV management that effectively suppresses CMV reactivation in the early stage at post-transplantation will be required to improve post-transplant outcomes, especially in high-risk patients.

Reactivation of human herpesvirus 6 in pediatric allogeneic hematopoietic stem cell transplant recipients

BACKGROUND

Reactivation of human herpesvirus 6 (HHV-6) occurs in 30%-50% of patients (pts) who receive allogeneic (allo) hematopoietic stem cell transplant (HCT). However, the recommendation for post-transplant HHV-6 monitoring and treatment in pediatric pts is not well established.

METHODS

HHV-6 incidence rates and the clinical outcomes were reported for 139 pediatric pts (≤18 years) undergoing first allo-HCT at City of Hope from July 2011 to July 2017, for whom HHV-6 was monitored weekly throughout HCT hospitalization. For 57 pediatric pts, who underwent first HCT from January 2009 to July 2011, HHV-6 was tested as clinically indicated and only rates of HHV-6 viremia were collected.

RESULTS

From July 2011 to July 2017, HHV-6 was detected in 88/139 pts (63%). The frequency of HHV-6 viremia was associated with malignant diagnoses, myeloablative conditioning, and cord blood HCT. Treatment with antiviral agents was offered to symptomatic pts with a higher viral load (VL), for whom the time to VL clearance was longer and the frequency of subsequent recurrences was higher. Pts with a lower VL cleared HHV-6 without treatment. HHV-6 viremia was associated with a higher frequency of grade II-IV acute graft-versus-host disease (GVHD) (P = .022), but did not affect overall survival (OS), disease-free survival (DFS), non-relapsed mortality (NRM), myeloid, or platelet (Plt) engraftment.

CONCLUSIONS

HHV-6 weekly screening is not necessary for all HCT pts but may be considered for high-risk pts with malignant diagnoses undergoing cord blood HCT; otherwise, HHV-6 should be tested as clinically indicated. Only symptomatic pts (especially with a high VL > 25 000) could benefit from treatment. HHV-6 viremia at the time of initiation and administration of the conditioning regimen cleared promptly without the need to augment the transplant process.

Presence of Parvovirus B19 but Not Herpesvirus Genome in Acute Skin Rash after Allogeneic Stem Cell Transplantation Correlates with Outcome

INTRODUCTION

Skin rash is a first symptom of acute graft-versus-host disease (GvHD) after allogeneic stem cell transplantation (ASCT) but can also be caused by viruses. The relevance of virus DNA analyses in skin rash for diagnosis and clinical outcome is unknown.

OBJECTIVES

To record the frequencies of detection of herpes and parvovirus B19 (ParvoB19) DNA in skin rash within 100 days after ASCT and to analyze their relevance for diagnosis, clinical course, and non-relapse mortality (NRM).

METHODS

We retrospectively identified 55 patients with virus DNA analysis for CMV, EBV, HHV6, HHV8, HSV, VZV, or ParvoB19. We assessed the rate of virus DNA detection and studied associations with histological diagnosis, virus DNA from concomitantly analyzed blood, clinical presentation, exanthema treatment, and NRM.

RESULTS

CMV, EBV, HHV6, HHV8, HSV, VZV and ParvoB19 DNA were detected in 12.5, 11.8, 10, 0, 0, 2.9, and 26.7% of exanthemas. Histopathological diagnosis was not associated with virus polymerase chain reaction (PCR) results. Detection of CMV, EBV, or HHV6 DNA but not ParvoB19 in skin and blood was associated with PCR results (p = 0.016; p < 0.001; p = 0.067; p = n.a.). Detection of CMV, EBV, HHV6, or ParvoB19 DNA in the skin was not significantly associated with patient, ASCT, or GvHD characteristics. Detection of ParvoB19 but not herpes virus DNA was associated with less immunosuppressive treatment (p = 0.015) and lower NRM (p = 0.041). In multivariate analyses, detection of ParvoB19 was associated with a lower NRM.

CONCLUSIONS

Detection of ParvoB19 DNA in exanthema after ASCT might be associated with lower NRM.

Characterization of an HLA-restricted and human cytomegalovirus-specific antibody repertoire with therapeutic potential

With an infection rate of 60-90%, the human cytomegalovirus (HCMV) is very common among adults but normally causes no symptoms. When T cell-mediated immunity is compromised, HCMV reactivation can lead to increased morbidity and mortality. HCMV antigens are processed and presented as peptides on the cell surface via HLA I complexes to the T cell receptor (TCR) of T cells. The generation of antibodies against HCMV peptides presented on HLA complexes (TCR-like antibodies) has been described, but is without therapeutic applications to date due to the polygenic and polymorphic nature of HLA genes. We set out to obtain antibodies specific for HLA/HCMV-peptides, covering the majority of HLA alleles present in European populations. Using phage display technology, we selected 10 Fabs, able to bind to HCMV-peptides presented in the 6 different HLA class I alleles A*0101, A*0201, A*2402, B*0702, B*0801 and B*3501. We demonstrate specific binding of all selected Fabs to HLA-typed lymphoblastoid cell lines (EBV-transformed B cells) and lymphocytes loaded with HCMV-peptides. After infection with HCMV, 4/10 tetramerized Fabs restricted to the alleles HLA-A*0101, HLA-A*0201 and HLA-B*0702 showed binding to infected primary fibroblasts. When linked to the pseudomonas exotoxin A, these Fab antibodies induce highly specific cytotoxicity in HLA matched cell lines loaded with HCMV peptides. TCR-like antibody repertoires therefore represent a promising new treatment modality for viral infections and may also have applications in the treatment of cancers.

Study of cytomegalovirus resistance in allogeneic hematopoietic cell transplant recipients

INTRODUCTION

Cytomegalovirus (CMV) is the most important opportunistic pathogen associated with transplant. The objective of this study was the characterization of CMV resistance mutations in allogeneic haematopoietic cell transplant recipients (allo-TPH) and the study of associated factors.

METHODS

A retrospective study of a cohort of allo-TPH recipients with post-transplant CMV reactivations with stable or increasing viral loads (CV), despite adequate antiviral treatment for at least 2weeks. The study of resistance mutations of the UL97 and UL54 genes was carried out by Sanger sequencing.

RESULTS

Refractory CMV infection in our group of allo-TPH patients corresponded with a 21.43% rate of resistant virus infection (3 of 14 patients). All patients with resistance mutations had multiple reactivation episodes (P-value .01). The mutations found were A594V and H520Q in the UL97 gene that confers high-grade resistance to ganciclovir (GCV). One of the 3 cases with antiviral resistance was documented with a low VL (< 1000 copies/ml) and short accumulated GCV treatment (41 days).

CONCLUSION

Most of the failures in the treatment of CMV were possibly due to clinical resistance; the lack of satisfactory response to antiviral treatment is not always accompanied by virological resistance. However, the appearance of resistances can occur early after the start of the treatment and with VL below 1000 copies / ml. The number of episodes of reactivation was higher among patients with virological resistance than those who did not.

Impact of Preemptive Therapy for Cytomegalovirus on Toxicities after Allogeneic Hematopoietic Cell Transplantation in Clinical Practice: A Retrospective Single-Center Cohort Study

(Val)ganciclovir (vGCV) or foscarnet (FCN) as preemptive therapy (PET) for cytomegalovirus (CMV) after allogeneic hematopoietic cell transplantation (HCT) is associated with myelosuppression and nephrotoxicity, respectively. We analyzed a cohort of CMV-seropositive (R⁺) HCT recipients managed preemptively at a single center. The objectives of our study were to (1) quantify the frequencies of neutropenia and acute kidney injury (AKI) through day +100 (D100) post-HCT and at PET discontinuation and (2) assess the impact of PET on neutropenia and AKI in multivariate models. This was a retrospective cohort study of adult CMV R⁺ recipients who underwent allo-HCT at Memorial Sloan Kettering Cancer Center from March 18, 2013, through December 31, 2017, and were managed with PET. Patients were grouped by receipt of PET (PET and no PET). Neutropenia and AKI were defined by Common Terminology Criteria for Adverse Events version 4. Frequencies of toxicities by D100 were compared between relevant groups. The impact of PET on toxicities was examined in univariate and multivariate Poisson/negative binomial regression models. Of 368 CMV R⁺ HCT recipients, 208 (56.5%) received PET. Neutropenia by D100 occurred in 41.8% and 28.6% patients in PET and no PET, respectively (P = .0009). PET increased the risk of neutropenia (adjusted relative risk = 1.81; 95% confidence interval [CI], 1.48 to 2.21; P < .0001) in multivariate analyses. AKI by D100 occurred in 12.0% and 7.8% patients in PET and no PET, respectively (P = .19). PET increased the risk of AKI by 2.75-fold (95% CI, 1.71 to 4.42; P < .0001). When PET recipients were grouped by first antiviral, neutropenia by D100 occurred in 34.8% and 48.9% of vGCV and FCN recipients, respectively, (P = .08), and AKI occurred in 13.0% and 34.0% of vGCV and FCN recipients, respectively (P = .001). At discontinuation of vGCV or FCN, neutropenia was present in 11.2% versus 2.1% patients, respectively (P = .08), and AKI was present in 1.9% of versus 12.8% patients respectively (P = .005). Preemptive therapy for CMV increased the risk of neutropenia and AKI in the first 100 days post-HCT by 1.8-fold and 2.8-fold, respectively. Our results underscore the need for safer antivirals for CMV management in HCT recipients.

The QuantiFERON Monitor® assay is predictive of infection post allogeneic hematopoietic cell transplantation

INTRODUCTION

Following allogeneic hematopoietic stem cell transplantation (alloHCT), excessive immunosuppression can be complicated by infection, while inadequate immunosuppression can result in graft-vs-host disease (GVHD). An accurate method to assess overall immune status post HCT is lacking. The QuantiFERON Monitor^® (QFM) assay measures interferon gamma (IFN-γ) release from whole blood following incubation with both innate (Toll-like receptor 7, TLR7) and adaptive (CD3 antibody) stimulants and may result in a more complete assessment of the immune system.

METHODS

Whole blood samples were prospectively collected from alloHCT recipients at conditioning followed by days 10, 30, 60, 90, 120, and 180 post-transplant and assayed by the QFM test. IFN-γ levels were correlated to time post HCT and episodes of infection and GVHD.

RESULTS

Forty patients were enrolled in the study (68% male; median age 47 years; 58% matched related donors, 42% unrelated; 33% myeloablative). Post-stimulation IFN-γ levels rose steadily over the first 180 days post transplantation. IFN-γ levels were significantly lower in those with active infection compared to those without during the neutropenic period (P < .001). The assay was predictive of CMV reactivation (VL > 1000 copies/mL) post alloHCT (P = .001).

CONCLUSION

This is a promising assay to demonstrate immune recovery and predict risk of infection after alloHCT and may allow tailoring of immunosuppression, antimicrobial treatment, and prophylaxis.

Epidemiology and outcome of invasive fungal disease in children after hematopoietic cell transplantation or treated for malignancy: Impact of national programme of antifungal prophylaxis

The objective of the study was the analysis of incidence and outcome of invasive fungal disease (IFD) in children treated for malignancy (PHO, paediatric hematology-oncology) or undergoing hematopoietic cell transplantation (HCT) over a period of six consecutive years in nationwide study. A total number of 5628 patients with newly diagnosed malignancies and 971 patients after HCT (741 allo-HCT and 230 auto-HCT) were screened for infectious complications in biennial reports. IFD incidence was lower among PHO patients: 8.8% vs 21.2% (P < .0001) and survival from IFD was better: 94.2% vs 84.1% (P < .0001). Auto-HCT patients had lower incidence (10.9% vs 24.4%) and lower mortality than allo-HCT patients. Introduction of national antifungal prophylaxis programme in HCT and acute leukaemia patients decreased incidence of IFD in HCT (from 23.1% to 13.4%) and AML on conventional chemotherapy (from 36% to 23%) but not in ALL patients during chemotherapy. In multivariate analysis, the incidence of IFD was higher in patients after HCT, diagnosed for ALL, AML or NHL, and in patients > 10 years old. Factors contributing to death with infection were as follows: undergoing HCT, diagnosis of acute leukaemia (ALL or AML) and duration of treatment of infection > 21 days. In conclusion, the incidence of IFD in allo-HCT and in AML patients on chemotherapy has decreased after introduction of national programme of antifungal prophylaxis, while the incidence of IFD in ALL patients on chemotherapy did not change significantly. The outcome of IFD both in PHO and HCT patients has largely improved in comparison with historical international data.

Modeling Human Cytomegalovirus in Humanized Mice for Vaccine Testing

Human cytomegalovirus (HCMV or HHV-5) is a globally spread pathogen with strictly human tropism that establishes a life-long persistence. After primary infection, high levels of long-term T and B cell responses are elicited, but the virus is not cleared. HCMV persists mainly in hematopoietic reservoirs, whereby occasional viral reactivation and spread are well controlled in immunocompetent hosts. However, when the immune system cannot control viral infections or reactivations, such as with newborns, patients with immune deficiencies, or immune-compromised patients after transplantations, the lytic outbursts can be severely debilitating or lethal. The development of vaccines for immunization of immune-compromised hosts has been challenging. Several vaccine candidates did not reach the potency expected in clinical trials and were not approved. Before anti-HCMV vaccines can be tested pre-clinically in immune-compromised hosts, reliable in vivo models recapitulating HCMV infection might accelerate their clinical translation. Therefore, immune-deficient mouse strains implanted with human cells and tissues and developing a human immune system (HIS) are being explored to test anti-HCMV vaccines. HIS-mice resemble immune-compromised hosts as they are equipped with antiviral human T and B cells, but the immune reactivity is overall low. Several groups have independently shown that HCMV infections and reactivations can be mirrored in HIS mice. However, these models and the analyses employed varied widely. The path forward is to improve human immune reconstitution and standardize the analyses of adaptive responses so that HIS models can be forthrightly used for testing novel generations of anti-HCMV vaccines in the preclinical pipeline.

Viral reactivations following hematopoietic stem cell transplantation in pediatric patients - A single center 11-year analysis

Viral reactivation occurs frequently in the context of immunodeficiency and immunosuppression after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and can cause severe complications. The aim of this single-center retrospective analysis was to characterize viral infections in the first year after HSCT, to investigate risk factors and to study the impact of viral infections on transplantation outcome. This will facilitate the identification of at-risk patients and the development of new preventive strategies. 107 pediatric allo-HSCT from January 2005 through December 2015 were analyzed for infections with Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), adenovirus (ADV), herpes simplex virus (HSV) and varicella zoster virus (VZV). Viral infections were detected after 68.2% of transplantations. The viruses most commonly encountered were HHV-6 (36/107) and EBV (30/107). Severe viral disease was rare (7/107) and none of the patients died as result of viral reactivation. Important risk factors for viral infections were higher age at HSCT, donor type and occurrence of acute graft-versus-host disease (aGvHD). Especially for EBV, transplant from an unrelated donor and in-vivo T-cell depletion (TCD) had a significant effect on infection rates, whereas for CMV the strongest effect was seen by donor and recipient serostatus with recipient seropositivity most predictive for reactivation. The occurrence of severe aGvHD was associated with EBV and ADV infections. For HSV, the recipient serostatus was identified as prognostic factor for HSV infections, while we found higher age at time of HSCT as risk factor for VZV infections. The overall survival of patients with or without viral infections did not differ significantly. Interestingly, when looking at the 85 patients in our cohort who had received an HSCT for a malignant disease, a tendency towards lower relapse rates was seen in patients affected by viral infections (HR 0.51, 95% CI 0.25 - 1.06, p = 0.072). Viral reactivations are common after pediatric allo-HSCT, though severe complications were rare in our collective. Determining risk factors for viral reactivations may help to identify patients in need of intensified monitoring and to individualize preventive strategies.

Infections after Allogenic Transplant with Post-Transplant Cyclophosphamide: Impact of Donor HLA Matching

Incidence and outcome of infections after allogeneic hematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PT-Cy) as graft-versus-host disease (GVHD) prophylaxis are largely unknown. Study aims were to estimate the incidence of pre-engraftment bloodstream infections (PE-BSIs) and viral infections (VIs; cytomegalovirus [CMV], adenovirus [ADV], human herpes virus 6 [HHV6], and BK-polyomavirus hemorrhagic-cystitis [BKPyV-HC]), their predictive factors, and infection-related mortality (IRM) after HSCT with PT-Cy. We analyzed 235 patients: 62%, 21%, and 17% received haploidentical (haplo), matched-unrelated donor (MUD), and matched-related donor, respectively. Overall, 72 patients had 77 PE-BSI episodes at a median time of 13 days after HSCT: cumulative incidence function (CIF) at 28 days was 32%, without differences among donor types (P = .988). By multivariate analysis, CIF of PE-BSI was higher in patients with severe neutropenia before HSCT (adjusted hazard ratio [AHR] = 2.90) and in multidrug-resistant Gram-negative bacteria rectal carriers (AHR = 2.68). IRM at 30 days was 5%, without differences by donor type (P = .106). Overall, 208 patients experienced ≥1 VIs (first occurrence among CMV, HHV6, ADV, BKPyV-HC) at a median time of 20 days after HSCT: CIF at 90 days was 91%, significantly higher in MUD and haplo (P = .0089). By multivariate analysis, also acute GVHD grade ≥2 (AHR = 1.32) and host/donor CMV-serology mismatch (positive/positive versus negative/negative: AHR = 2.95, positive/negative versus negative/negative: AHR = 2.41, negative/positive versus negative/negative: AHR = 2.35) affected VIs occurrence. IRM at 180 days was 8%, without differences among donor types (P = .106). In conclusion, study results did not show a significant impact of donor type on PE-BSI incidence; conversely, MUD and haploidentical transplants retained a higher occurrence of VIs in the early phase after HSCT.

Cytomegalovirus reactivation after bortezomib treatment for multiple myeloma and light chain amyloidosis

OBJECTIVE

Cytomegalovirus (CMV) is an opportunistic herpesvirus, and reactivation of infection is possible in immunocompromised patients. Historically, the risk for haematology patients is restricted to those treated with an allogeneic transplant or T-cell depleting agents. Bortezomib is a highly efficacious proteasome inhibitor widely used to treat multiple myeloma and light chain (AL) amyloidosis patients. The objective of this small prospective study was to quantify the risk of CMV reactivation associated with bortezomib treatment.

METHODS

Fifty-seven consecutive multiple myeloma or AL amyloidosis patients commencing bortezomib-based therapy were included. Viral copy numbers were established at baseline and then at fortnightly intervals during treatment. Pre-emptive anti-viral treatment was initiated in patients with a viral load >7500 copies/mL.

RESULTS

Reactivation of CMV was detected in 39% (n = 12/31) of seropositive bortezomib treated patients compared with 0% of CMV seronegative patients. Detectable DNAemia developed during the first two cycles of treatment in 83% (n = 10/12) patients. Anti-viral treatment was initiated in 42% (n = 5/12), but no cases of active CMV disease were seen.

CONCLUSION

This study suggests that there is a substantial risk of CMV reactivation in CMV-seropositive plasma cell dyscrasia patients treated with bortezomib.

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.

Safety profile of the concomitant use of foscarnet and aerosolized pentamidine in allogeneic hematopoietic stem cell transplantation recipients

BACKGROUND

Concomitant use of foscarnet and intravenous pentamidine can very frequently cause severe hypocalcemia. However, it is unknown whether aerosolized pentamidine has a similar adverse interaction with foscarnet. The present study was aimed at examining the safety profile of concomitantly used foscarnet and aerosolized pentamidine in patients receiving allogeneic hematopoietic stem cell transplantation.

METHODS

Data from allogeneic hematopoietic stem cell recipients who had been administered foscarnet therapy for over 7 days were analyzed. We compared electrolyte abnormalities and serum creatinine level between patients who received aerosolized pentamidine concomitantly and those who did not.

RESULTS

A total of 84 consecutive patients and 135 episodes of foscarnet therapy between May 2011 and April 2016 were evaluable. Of these 135 episodes, 25 episodes of therapy included concurrent therapy with 300 mg dose of aerosolized pentamidine once a month (pentamidine group) and 110 episodes did not (non-pentamidine group). The incident rates of grade 3/4 hypocalcemia did not significantly differ between the pentamidine and non-pentamidine groups (P = .207; 0/25 [0%] vs 10/110 [9.1%], respectively). In addition, we observed no significant difference in the incident rates of grade 3/4 serum creatinine increase between the two groups (P = 1.00; 0/25 [0%] vs 4/110 [3.6%], respectively).

CONCLUSION

Our results suggest that the drug interactions between foscarnet and aerosolized pentamidine may not be clinically significant.

Epidemiology, Outcome and Risk Factors Analysis of Viral Infections in Children and Adolescents Undergoing Hematopoietic Cell Transplantation: Antiviral Drugs Do Not Prevent Epstein-Barr Virus Reactivation

Objective

The analysis of epidemiology, risk factors and outcome of viral infections in children and adolescents after hematopoietic cell transplantation (HCT).

Methods

In this multicenter nationwide study a total of 971 HCT procedures (741 allo-HCT; 230 auto-HCT) over a period of 6 years were analyzed.

Results

During this period 801 episodes of viral infections were diagnosed in 442 patients. The incidence of viral infections was 57.9% in allo-HCT and 4.8% in auto-HCT patients. The most frequent infections after allo-HCT were caused by cytomegalovirus (CMV), polyoma BK virus (BKV) and Epstein-Barr virus (EBV). The majority of infections occurred within the first 4 months after allo-HCT and over 80% required pharmacotherapy or symptomatic therapy. The median time of treatment of specific viral infection ranged from 7 (for EBV) to 24 (for CMV) days. The highest mortality was observed in case of CMV infection. The risk factors for viral infections were allo-HCT, acute leukemia, acute and chronic graft versus host disease (a/cGVHD), and matched unrelated donor (MUD)/mismatched unrelated donor (MMUD)-HCT. The risk factor for death from viral infection were CMV-IgG seropositivity in acute lymphoblastic leukemia recipient, and MUD/MMUD-HCT. The incidence of EBV infection requiring pre-emptive treatment with rituximab in allo-HCT children was 19.3%. In 30.8% cases of EBV infection, these episodes were preceded by other viral infection and treated with antivirals, which did not prevent development of EBV-DNA-emia with need of rituximab treatment in 81.5% cases. In 47.7% of these cases, GVHD was a factor enabling development of significant EBV-DNA-emia during antiviral therapy of other infection.

Conclusion

We have shown that antiviral drugs do not prevent EBV reactivation in allo-HCT pediatric patients.

Infection profile in children and adolescents with bone marrow failures treated with allogeneic hematopoietic stem cell transplantation

BACKGROUND

The objective of the study was to analyze the profile of infections in children with BMF following alloHCT.

METHODS

Data of 169 consecutive children with inherited and acquired BMF treated with alloHCT between 2012 and 2017 in Polish pediatric transplant departments were analyzed in registry-based retrospective study, with respect to the type of infection, and clinical outcome.

RESULTS

At least 1 infection was diagnosed in 107/169 patients (60.4%). In total, 182 infections were diagnosed. The most common were VI (96; 52.7%), followed by BI (71; 39.0%), and FI (15; 8.2%), P < .001. The most common etiological factors of VI were as follows: CMV (38.5%), EBV (22.9%), and BK virus (24%); while of BI were as follows: Staphylococcus spp. (17; 23.9%), Enterococcus faecium (10; 14.1%), and Klebsiella pneumoniae (9; 12.7%). No difference was found between the occurrence of infections with respect to donor type, graft source, and conditioning type. GvHD had no impact on the incidence of VI, BI, and FI. Fifteen FI were diagnosed in 12 patients, of which 14 FI were diagnosed in children transplanted for FA. Of total 107 children, 9 died (8.4%), of which 4 (3.7%) due to infections: bacterial sepsis (2) and invasive FI (2).

CONCLUSION

Infections in children with BMF following alloHCT remain an important cause of morbidity. Children with FA had high incidence of FI. In our analysis, aGvHD had no impact on the occurrence on infections, although the study was not strong enough to prove such a difference.

A Replication-Defective Human Cytomegalovirus Vaccine Elicits Humoral Immune Responses Analogous to Those with Natural Infection

Human cytomegalovirus (HCMV) can cause congenital infections, which are a leading cause of childhood disabilities. Since the rate of maternal-fetal transmission is much lower in naturally infected (HCMV-seropositive) women, we hypothesize that a vaccine candidate capable of eliciting immune responses analogous to those of HCMV-seropositive subjects may confer protection against congenital HCMV. We have previously described a replication-defective virus vaccine based on strain AD169 (D. Wang, D. C. Freed, X. He, F. Li, et al., Sci Transl Med 8:362ra145, 2016, https://doi.org/10.1126/scitranslmed.aaf9387). The vaccine, named V160, has been shown to be safe and immunogenic in HCMV-seronegative human subjects, eliciting both humoral and cellular immune responses (S. P. Adler, S. E. Starr, S. A. Plotkin, S. H. Hempfling, et al., J Infect Dis 220:411-419, 2019, https://doi.org/10.1093/infdis/171.1.26). Here, we further showed that sera from V160-immunized HCMV-seronegative subjects have attributes similar in quality to those from seropositive subjects, including high-avidity antibodies to viral antigens, coverage against a panel of genetically distinct clinical isolates, and protection against viral infection in diverse types of human cells in culture. More importantly, vaccination appeared efficient in priming the human immune system, inducing memory B cells in six V160 recipients at frequencies comparable to those of three HCMV-seropositive subjects. Our results demonstrate the ability of V160 to induce robust and durable humoral memory responses to HCMV, justifying further clinical evaluation of the vaccine against congenital HCMV.IMPORTANCE In utero HCMV infection can lead to miscarriage or childhood disabilities, and an effective vaccine is urgently needed. Since children born to women who are seropositive prior to pregnancy are less likely to be affected by congenital HCMV infection, it has been hypothesized that a vaccine capable of inducing an immune response resembling the responses in HCMV-seropositive women may be effective. We previously described a replication-defective virus vaccine that has been demonstrated safe and immunogenic in HCMV-seronegative subjects. Here, we conducted additional analyses to show that the vaccine can induce antibodies with functional attributes similar to those from HCMV-seropositive subjects. Importantly, vaccination can induce long-lived memory B cells at frequencies comparable to those seen in HCMV-seropositive subjects. We conclude that this vaccine is a promising candidate that warrants further clinical evaluation for prevention of congenital HCMV.

Anti-herpesvirus prophylaxis, pre-emptive treatment or no treatment in adults undergoing allogeneic transplant for haematological disease: systematic review and meta-analysis

BACKGROUND

Herpesviridae infections incur significant morbidity and indirect effects on mortality among allogeneic haematopoietic cell transplant (allo-HCT) recipients.

OBJECTIVES

To study the effects of antiviral prevention strategies among haemato-oncological individuals undergoing allo-HCT.

DATA SOURCES

Cochrane Central Register of Controlled Trials, MEDLINE, Embase and LILACS. We further searched for conference proceedings and trial registries.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs).

PARTICIPANTS

Adults with haematological malignancy undergoing allo-HCT.

INTERVENTIONS

Antiviral prophylaxis versus no treatment/placebo or pre-emptive treatment and pre-emptive treatment versus prophylaxis with the same agent.

METHODS

Random-effects meta-analysis was conducted computing pooled risk ratios (RR) with 95% CI and the inconsistency measure (I²). The certainty of the evidence was appraised by GRADE.

RESULTS

We included 22 RCTs. Antiviral prophylaxis reduced all-cause mortality (RR 0.83, 95% CI 0.7-0.99; 15 trials, I² = 0%), cytomegalovirus (CMV) disease (RR 0.54, 95% CI 0.34-0.85; n = 15, I² = 20%) and herpes simplex virus (HSV) disease (RR 0.29, 95% CI 0.2-0.43; n = 13, I² = 18%) compared with no treatment/placebo or pre-emptive treatment, all with high-certainty evidence. Furthermore, antivirals reduced HSV infection, CMV pneumonitis, CMV infection and varicella zoster virus disease. Anti-CMV prophylaxis (+/- pre-emptive treatment) compared with pre-emptive treatment alone reduced non-significantly all-cause mortality (RR 0.78, 95% CI 0.6-1.02; n = 8, I² = 0%), CMV disease (RR 0.47, 95% CI 0.23-0.97; n = 9, I² = 30%) and HSV disease (RR 0.41, 95% CI 0.24-0.67; n = 4, I² = 0%) with high-certainty evidence, as well as CMV and HSV infections. Antiviral prophylaxis did not result in increased adverse event rates overall or more discontinuation due to adverse events.

CONCLUSIONS

Antiviral prophylaxis directed against herpesviruses is highly effective and safe, reducing mortality, HSV and CMV disease, as well as herpesvirus reactivations among allo-HCT recipients. Anti-CMV prophylaxis is more effective than pre-emptive treatment alone with respect to HSV and CMV disease and infection.

Early Experience With CliniMACS Prodigy CCS (IFN-gamma) System in Selection of Virus-specific T Cells From Third-party Donors for Pediatric Patients With Severe Viral Infections After Hematopoietic Stem Cell Transplantation

Viral reactivation is a frequent complication of allogeneic hematopoietic stem cell transplantation especially in children. For refractory cases, rapid virus-specific T-cell therapy would be ideally implemented within a few days. Over the course of a year in our pediatric cohort of 43 allogeneic transplantation, 9 patients fulfilled criteria for virus-specific T-cell therapy. Viral infections were due to cytomegalovirus (CMV) in 3, Epstein-Barr virus (EBV) in 2, and adenovirus (AdV) in 1 case, whereas >1 virus was detected in 3 cases. Viral diseases necessitating a T-cell therapy were CMV pneumonitis and colitis, AdV enteritis and cystitis, and EBV-induced posttransplantation lymphoproliferative disease. Cells were produced by the CliniMACS Prodigy CCS (IFN-gamma) System within 24 hours after mononuclear leukapheresis. Eight patients became completely asymptomatic, whereas 7 also cleared the virus. Six patients are alive without viral illness or sequelae demonstrating viral DNA clearance in peripheral blood with a median follow-up of 535 (350-786) days. One patient with CMV pneumonitis died of respiratory insufficiency. In 2 cases the viral illness improved or cleared, however, the patients died of invasive aspergillosis. No cases of graft-versus-host disease, rejection, organ toxicity, or recurrent infection were noticed. Virus-specific T-cell therapy implemented by the CliniMACS Prodigy CCS (IFN-gamma) System is an automated, fast, safe, and probably effective way to control resistant viral diseases after pediatric hematopoietic stem cell transplantation.

CMV Management with Specific Immunoglobulins: A Multicentric Retrospective Analysis on 92 Allotransplanted Patients

CMV represents one of the most severe life-threatening complications of allogeneic stem cell transplantation (allo-SCT). Pre-emptive treatment is highly effective, but toxicity and repetitive reactivation of CMV represent a significant challenge in the clinical practice. The use of anti-CMV specific immunoglobulins (Megalotect) is controversial. We retrospectively collected data on 92 patients submitted to allo-SCT for hematological malignancies, in whom Megalotect was used either for prophylaxis (n=14) or with pre-emptive therapy, together with an anti-CMV specific drug (n=78). All the patients were considered at high-risk, due to the presence of at least one risk factor for CMV reactivation. The treatment was well tolerated, with no reported infusion reactions, nor other adverse events, none of the 14 cases treated with Megalotect as prophylaxis developed CMV reactivation. 51/78 (65%) patients who received Megalotect during pre-emptive treatment achieved complete clearance of CMV viremia, and 14/51 patients (29%) developed a breakthrough CMV infection. 7/78 patients (9%) developed CMV disease. The projected 1-year OS, 1-year TRM, and 1-year RR is 74%, 15%, and 19%, respectively. No differences were observed in terms of OS, TRM, and RR by comparing patients who achieved a complete response after treatment versus those who did not. These retrospective data suggest that Megalotect is safe and well-tolerated. When used as prophylaxis, no CMV reactivation was recorded. Further prospective trials are warranted to identify the best set of patients who can benefit from Megalotect alone or in addition to anti-CMV specific drugs.

Age-dependent determinants of infectious complications profile in children and adults after hematopoietic cell transplantation: lesson from the nationwide study

Incidence and outcome of microbiologically documented bacterial/viral infections and invasive fungal disease (IFD) in children and adults after hematopoietic cell transplantation (HCT) were compared in 650 children and 3200 adults in multicenter cross-sectional nationwide study. Infections were diagnosed in 60.8% children and 35.0% adults, including respectively 69.1% and 63.5% allo-HCT, and 33.1% and 20.8% auto-HCT patients. The incidence of bacterial infections was higher in children (36.0% vs 27.6%; p < 0.0001). Infections with Gram-negative bacteria were more frequent than Gram-positives in adults (64.6% vs 44.8%; p < 0.0001). Outcome of bacterial infections was better in children (95.5% vs 91.4%; p = 0.0011). The IFD incidence (25.3% vs 6.3%; p < 0.0001) and outcome (88.0% vs 74.9%; p < 0.0001) were higher in children. The incidence of viral infections was higher in children after allo-HCT (56.3% vs 29.3%; p < 0.0001), and auto-HCT (6.6% vs 0.8%; p < 0.0001). Outcome of viral infections was better in children (98.6% vs 92.3%; p = 0.0096). Infection-related mortality was 7.8% in children and 18.4% in adults (p < 0.0001). No child after auto-HCT died of infection. Adult age, mismatched transplants, acute leukemia, chronic GVHD, CMV reactivation, infection with Gram-negatives, and duration of infection > 21 days were risk factors for death from infection. In conclusion, pediatric patients have 2.9-fold higher incidence and 2.5-fold better outcome of infections than adults after HCT.

Guidelines from the 2017 European Conference on Infections in Leukaemia for management of HHV-6 infection in patients with hematologic malignancies and after hematopoietic stem cell transplantation

Of the two human herpesvirus 6 (HHV-6) species, human herpesvirus 6B (HHV-6B) encephalitis is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplant. Guidelines for the management of HHV-6 infections in patients with hematologic malignancies or post-transplant were prepared a decade ago but there have been no other guidelines since then despite significant advances in the understanding of HHV-6 encephalitis, its therapy, and other aspects of HHV-6 disease in this patient population. Revised guidelines prepared at the 2017 European Conference on Infections in Leukaemia covering diagnosis, preventative strategies and management of HHV-6 disease are now presented.

Death after hematopoietic stem cell transplantation: changes over calendar year time, infections and associated factors

Information on incidence, and factors associated with mortality is a prerequisite to improve outcome after hematopoietic stem cell transplantation (HSCT). Therefore, 55'668 deaths in 114'491 patients with HSCT (83.7% allogeneic) for leukemia were investigated in a landmark analysis for causes of death at day 30 (very early), day 100 (early), at 1 year (intermediate) and at 5 years (late). Mortality from all causes decreased from cohort 1 (1980-2001) to cohort 2 (2002-2015) in all post-transplant phases after autologous HSCT. After allogeneic HSCT, mortality from infections, GVHD, and toxicity decreased up to 1 year, increased at 5 years; deaths from relapse increased in all post-transplant phases. Infections of unknown origin were the main cause of infectious deaths. Lethal bacterial and fungal infections decreased from cohort 1 to cohort 2, not unknown or mixed infections. Infectious deaths were associated with patient-, disease-, donor type, stem cell source, center, and country- related factors. Their impact varied over the post-transplant phases. Transplant centres have successfully managed to reduce death after HSCT in the early and intermediate post-transplant phases, and have identified risk factors. Late post-transplant care could be improved by focus on groups at risk and better identification of infections of "unknown origin".