Observational prospective study of viral infections in children undergoing allogeneic hematopoietic cell transplantation: a 3-year GETMON experience

Antiviral cellular therapy for enhancing T-cell reconstitution before or after hematopoietic stem cell transplantation (ACES): a two-arm, open label phase II interventional trial of pediatric patients with risk factor assessment

Viral infections remain a major risk in immunocompromised pediatric patients, and virus-specific T cell (VST) therapy has been successful for treatment of refractory viral infections in prior studies. We performed a phase II multicenter study (NCT03475212) for the treatment of pediatric patients with inborn errors of immunity and/or post allogeneic hematopoietic stem cell transplant with refractory viral infections using partially-HLA matched VSTs targeting cytomegalovirus, Epstein-Barr virus, or adenovirus. Primary endpoints were feasibility, safety, and clinical responses (>1 log reduction in viremia at 28 days). Secondary endpoints were reconstitution of antiviral immunity and persistence of the infused VSTs. Suitable VST products were identified for 75 of 77 clinical queries. Clinical responses were achieved in 29 of 47 (62%) of patients post-HSCT including 73% of patients evaluable at 1-month post-infusion, meeting the primary efficacy endpoint (>52%). Secondary graft rejection occurred in one child following VST infusion as described in a companion article. Corticosteroids, graft-versus-host disease, transplant-associated thrombotic microangiopathy, and eculizumab treatment correlated with poor response, while uptrending absolute lymphocyte and CD8 T cell counts correlated with good response. This study highlights key clinical factors that impact response to VSTs and demonstrates the feasibility and efficacy of this therapy in pediatric HSCT.

Generation of good manufacturing practice grade virus-specific T cells for the management of post-transplant CMV infections

Adoptive transfer of antigen-specific T cells has recently emerged as a successful strategy to treat viral infections following hematopoietic cell transplantation (HCT). Ex-vivo expanded donor-derived virus-specific T cells (VSTs) can be safe and effective, devoid of all the drug-related adverse effects. The study aimed to manufacture cGMP grade VSTs from healthy donors, characterize the VST product and demonstrate its safety and efficacy. Peripheral blood mononuclear cells (PBMCs) collected from six healthy donors were stimulated with pepmix that mimics the pp65 antigenic epitope of CMV and cultured for 14 days in G-Rex culture tubes. Post pepmix exposure and expansion the median CD3% was 98.8% (range:95.5% to 99.9%) while the median CD4% and CD8% were 49.1% (range:21.3% to 86.6%) and 43.9% (range:12.7% to 75.5%) respectively. The percentage of IFNγ+ cells was much higher among the CD8+ T cells (median - 18.47%; range 6.50% - 45.82%) when compared to CD4+ T cells (median - 2.74%; range 0.47% - 18.58%) and there was a switch from the CD45RA+ naive phenotype to CD45RA- effector memory phenotype in the 4 samples that achieved a >5 fold expansion. The VSTs were cytotoxic to the pepmix pulsed lymphoblasts (efficacy) while they did not induce cytolysis in the lymphoblasts that were not exposed to the pepmix (safety). This feasibility exercise helped us optimize the starting cell dose for the culture and clinical grade culture strategies, subset characterization and cytotoxicity assays. The approach could be applied to the clinical practice where virus-specific T cell infusions could be given for post-transplant viral infections.

Management of Chronic Graft-vs.-Host Disease in Children and Adolescents With ALL: Present Status and Model for a Personalised Management Plan

Herein we review current practice regarding the management of chronic graft-vs.-host disease (cGvHD) in paediatric patients after allogeneic haematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukaemia (ALL). Topics covered include: (i) the epidemiology of cGvHD; (ii) an overview of advances in our understanding cGvHD pathogenesis; (iii) current knowledge regarding risk factors for cGvHD and prevention strategies complemented by biomarkers; (iii) the paediatric aspects of the 2014 National Institutes for Health-defined diagnosis and grading of cGvHD; and (iv) current options for cGvHD treatment. We cover topical therapy and newly approved tyrosine kinase inhibitors, emphasising the use of immunomodulatory approaches in the context of the delicate counterbalance between immunosuppression and immune reconstitution as well as risks of relapse and infectious complications. We examine real-world approaches of response assessment and tapering schedules of treatment. Furthermore, we report on the optimal timepoints for therapeutic interventions and changes in relation to immune reconstitution and risk of relapse/infection. Additionally, we review the different options for anti-infectious prophylaxis. Finally, we put forth a theory of a holistic view of paediatric cGvHD and its associated manifestations and propose a checklist for individualised risk evaluation with aggregated considerations including site-specific cGvHD evaluation with attention to each individual's GvHD history, previous medical history, comorbidities, and personal tolerance and psychosocial circumstances. To complement this checklist, we present a treatment algorithm using representative patients to inform the personalised management plans for patients with cGvHD after HSCT for ALL who are at high risk of relapse.

Association between Antiviral Prophylaxis and Cytomegalovirus and Epstein-Barr Virus DNAemia in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplant

Background: Epstein–Barr virus (EBV) and cytomegalovirus (CMV) infections can have serious consequences during the period of aplasia and lymphopenia following hematopoietic stem cell transplantation (HSCT). Large pediatric cohort studies examining the effect of antiviral prophylaxis against these viruses are scarce. The present study aimed to analyse the potential effect of antiviral prophylaxis (acyclovir and famciclovir) on active post-transplant EBV and CMV infection in a pediatric cohort of allogeneic HSCT recipients. Methods: We used data from the TREASuRE cohort, consisting of 156 patients who had a first allogeneic HSCT, enrolled in four pediatric centers in Canada between July 2013 and March 2017. Follow-up was performed from the time of transplant up to 100 days post-transplant. Adjusted hazard ratio (HR) with 95% confidence intervals (CI) for the association between antiviral prophylaxis with acyclovir and/or famciclovir and EBV and CMV DNAemia was estimated using multivariate Cox regression models. Results: The post-transplant cumulative incidence of EBV and CMV DNAemia at 100 days of follow-up were, respectively, 34.5% (95% CI: 27.6–42.6) and 19.9% (95% CI: 14.5–27.1). For acyclovir, the adjusted hazard ratio (HR) for CMV and EBV DNAemia was 0.55 (95% CI: 0.24–1.26) and 1.41 (95% CI: 0.63–3.14), respectively. For famciclovir, the adjusted HR were 0.82 (95% CI: 0.30–2.29) and 0.79 (95% CI: 0.36–1.72) for CMV and EBV DNAemia, respectively. Conclusion: The antivirals famciclovir and acyclovir did not reduce the risk of post-transplant CMV and EBV DNAemia among HSCT recipients in our pediatric population.

Follow-up of human adenovirus viral load in pediatric hematopoietic stem cell transplant recipients

BACKGROUND

The spectrum of human adenovirus (HAdV)-related disease is broad, and the virus acts on many organs and systems in hematopoietic stem cell transplantation (HSCT) recipients. We aimed to evaluate the effect of HAdV-DNA positivity with clinical and laboratory findings 4 months after HSCT.

METHODS AND RESULTS

We retrospectively investigated HAdV-DNA in 153 HSCT recipients (≤18 years) by quantitative real-time polymerase chain reaction (RealStar; Altona Diagnostics). The results of samples from January 2014 to December 2017 are included. HAdV-DNA was positive for at least one sample type in 50 (32.67%) patients. HAdV-DNA positivity rate was 8.92% (N: 145/1625), 40.25% (N: 64/159), and 25% (N: 2/8) for plasma, stool, and urine samples, respectively. HAdV-DNA was positive in the plasma of 38 (24.83%) patients at a median 16 (range: 1-58 days) days after HSCT. The mortality rate was 23.68% and 6.95% in plasma HAdV-positive and HAdV-negative patients (p = .014). Moreover, HAdV-DNA positivity had an impact on overall survival for allogeneic-HSCT (p = .013), with the cumulative effect including graft-versus-host disease state in multivariate analysis (p = .014).

CONCLUSIONS

Plasma HAdV-DNA positivity is a potential influencer that decreases survival in the early post-transplant period. Due to the high mortality rates, close monitoring is required of HAdV infections after HSCT with sensitive methods, especially at the early stage.

Epidemiology and clinical characteristics of viral infections in hospitalized children and adolescents with cancer in Lebanon

Background

Viral infections in children and adolescents with malignancy are commonly encountered and have a significant impact on morbidity and mortality. Studies and epidemiological data regarding viral infections in children with cancer in developing countries are lacking. This retrospective cohort study aims to assess the burden of viral infections in children and adolescents with cancer, by assessing prevalence, risk factors, as well as morbidity and mortality of common viruses over a period of 8 years.

Methods and findings

Medical records of cancer patients treated at the Children Cancer Center of Lebanon were reviewed and 155 participants under the age of 21 were identified with at least one documented viral infection during the period from July 2009 to November 2017. This subset included 136 participants with active malignancy and 19 participants with a history of cancer who underwent hematopoietic stem cell transplantation [HSCT] and were in remission; the latter group was analyzed separately. Information regarding participant characteristics, hospital course, and complications were obtained. Associations between viral infections and certain factors were assessed. In the cohort, 64% were male, 81% were Lebanese. In participants with active malignancy, 90% received chemotherapy in the 6 months preceding the viral infection episode, 11% received radiotherapy. 51% of participants were neutropenic at the time of viral detection, and 77% were lymphopenic. 17% experienced a bacterial co-infection, and 3 experienced a viral co-infection. Among 162 viral infection episodes, clinically diagnosed skin infections, mainly herpes simplex virus type 1 and varicella-zoster virus, were the most common [44% of cases]. These were followed by laboratory-proven systemic herpes infections: cytomegalovirus [14%] and Epstein-Barr virus [6%]. Respiratory viruses: influenza and respiratory syncytial virus, accounted for 9% and 4%, respectively, whereas rotavirus represented 11% and BK virus represented 3% of cases. Acute lymphocytic leukemia was the most prevalent neoplasia [57%]. Fever was the most common presenting symptom [55%] and febrile neutropenia was the reason for admission in 24% of cases. The mean length of stay was significantly longer in participants with cytomegalovirus infections and significantly lower in rotavirus infection. Admission to the ICU occurred in 9%, complications in 8%, and mortality in 5%. Participants with viral infections post-HSCT were noted to have a significantly longer length of hospital stay compared to non-HSCT participants, with no other significant differences in clinical course and outcome. The study was limited by its retrospective nature and by the late introduction and underuse of multiplex PCR panels, which may have led to underdiagnosis of viral infections.

Conclusions

Viral infections were prevalent in our sample of cancer patients and may have contributed to morbidity and mortality. Newly available viral diagnostics are likely to vastly increase the number and scope of detectable viral infections in this population. Prospective studies using multiplex PCR technology with systematic testing of patients will be more helpful in defining the burden of viral infections. Furthermore, efforts at antimicrobial stewardship would benefit from the identification of viral causes of infection and limit the unnecessary use of antibiotics in the pediatric cancer population.

Delaying haematopoietic stem cell transplantation in children with viral respiratory infections reduces transplant-related mortality

Viral respiratory infections (VRIs) contribute to the morbidity and transplant‐related mortality (TRM) after allogeneic haematopoietic stem cell transplantation (HSCT) and strategies to prevent and treat VRIs are warranted. We monitored VRIs before and after transplant in children undergoing allogeneic HSCT with nasopharyngeal aspirates (NPA) and assessed the impact on clinical outcome. Between 2007 and 2017, 585 children underwent 620 allogeneic HSCT procedures. Out of 75 patients with a positive NPA screen (12%), transplant was delayed in 25 cases (33%), while 53 children started conditioning with a VRI. Patients undergoing HSCT with a positive NPA screen had a significantly lower overall survival (54% vs. 79%) and increased TRM (26% vs. 7%) compared to patients with a negative NPA. Patients with a positive NPA who delayed transplant and cleared the virus before conditioning had improved overall survival (90%) and lower TRM (5%). Pre‐HSCT positive NPA was the only significant risk factor for progression to a lower respiratory tract infection and was a major risk factor for TRM. Transplant delay, whenever feasible, in case of a positive NPA screen for VRIs can positively impact on survival of children undergoing HSCT.

Outcomes of Human Adenovirus Infection and Disease in a Retrospective Cohort of Pediatric Hematopoietic Cell Transplant Recipients

BACKGROUND

Human adenoviruses (HAdVs) are associated with significant morbidity and death after hematopoietic cell transplantation (HCT). In this study, we sought to determine the incidence of HAdV infection among pediatric HCT recipients in the polymerase chain reaction (PCR) testing era, identify risk factors for viremia among patients undergoing HAdV surveillance, and assess the effectiveness of preemptive cidofovir.

METHODS

A single-center retrospective cohort of patients who underwent a transplant within a 10-year period was assembled. The incidence of and outcomes of patients with HAdV infection and disease were determined by PCR results and chart review. A Cox regression model was used for surveilled allogeneic HCT recipients to identify factors associated with viremia. We also used a discrete-time failure model with inverse probability treatment weights to assess the effectiveness of preemptive cidofovir for infection.

RESULTS

Among 572 HCT recipients, 76 (13.3%) had ≥1 sample that was HAdV PCR positive (3.5% of autologous HCT recipients and 19.7% of allogeneic HCT recipients). Among 191 allogeneic HCT recipients under surveillance, 58 (30.4%) had HAdV detected from any source, and 50 (26.2%) specifically had viremia. The mortality rate was higher in allogeneic HCT recipients with HAdV infection versus those without infection (25.9% vs 11.3%; P = .01). Factors associated with infection included an age of 6 to 12 years, an absolute lymphocyte count of <200 cells/μL, recent prednisone exposure, and recent bacteremia. Preemptive cidofovir was not associated with a reduced risk of infection progression (odds ratio, 0.96 [95% confidence interval, 0.30-3.05]).

CONCLUSIONS

HAdV infection is common and associated with an increased rate of death after allogeneic HCT. Using prediction models that incorporate factors associated with HAdV might help target surveillance. Preemptive cidofovir therapy was not protective in a subset of HAdV-positive patients. Larger observational or randomized investigations are necessary, because the utility of surveillance requires effective preemptive therapies.

Viral infections and immune reconstitution interaction after pediatric allogenic hematopoietic stem cell transplantation

Background: Viral infections are a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Although immune suppression plays a central role, the literature shows conflicting results on interplay between post-transplant immune reconstitution (IR) and viral infections. Methods: We prospectively studied viral infections and IR in 30 pediatric patients undergoing allogenic HSCT, with a follow-up time of 24 months. In total, 1337 blood (CMV, EBV, HHV-6, ADV and BKV) and urine (BKV and JCV) virus samples were analyzed. IR including B-cells (CD19+), T cells (CD3+, CD4+, CD8+) and NK-cells were measured. Clinical outcomes included overall survival (OS), non-relapse mortality (NRM), graft-versus-host disease (GVHD) and occurrence of blood culture positive bacterial infections. Results: We found BKV reactivation to be most frequent, 47% of the children had viremia and 77% viruria. The frequencies of CMV, HHV-6 and adeno viremia were 37%, 37% and 6%, respectively. Viremias beyond 3 months post-HSCT were uncommon. Factors such as GVHD, use of steroids, EBV and CMV infections and pre-transplant irradiation affected IR. No specific viral infection or IR related factor was associated to OS or NRM. Conclusions: Viral infections and IR interact in a bi-directional manner. Accordingly, close follow-up of both IR and viral loads is warranted.

[Application of multiplex PCR assay to study early multiple herpesviruses infection during HSCT]

目的

采用多重PCR方法分析造血干细胞移植（HSCT）患者多种疱疹病毒的感染状况，并探讨HSCT患者多种疱疹病毒感染与临床特征的相关性及其对移植并发症和预后的影响。

方法

以苏州大学附属第一医院血液科2017年2月至2017年8月行HSCT的90例患者为研究对象，收集预处理至移植后90 d内不同时间点的外周血标本共734份，Lab-Aid824核酸提取Mini试剂抽提DNA，应用多重PCR方法同时扩增8种人类疱疹病毒，分析多种疱疹病毒感染发生率及其与临床特征的相关性及对移植后并发症和预后的影响。

结果

至随访终点，中位随访时间为192（35~308）d。移植前疱疹病毒感染发生率为35.6%（32/90），其中1种疱疹病毒感染发生率为12.2%（11/90），多种病毒感染的发生率为23.3%（21/90）。移植后疱疹病毒感染发生率为77.8%（70/90），其中1种疱疹病毒感染发生率为20.0%（18/90），多种疱疹病毒感染的发生率为57.8%（52/90）。在多种疱疹病毒感染的患者中，2种病毒感染30例（57.7%），3种疱疹病毒感染18例（34.6%），不同时间点样本检测的4种疱疹病毒感染4例（7.7%）。移植后多种疱疹病毒感染中，HHV-6和HHV-7感染存在相关性（OR=13.880，Q=0.026），EBV和HHV-7感染也存在相关性（OR=0.093，Q=0.044）。25例患者移植后出现疱疹病毒感染相关临床表现，主要为出血性膀胱炎、间质性肺炎、肠炎、病毒性脑炎和不明原因发热。移植前HHV-1感染与年龄、HHV-2感染与发病时间、CMV感染与原发病为淋巴瘤具有一定的相关性。移植后EBV感染与HLA不全相合、供受者ABO血型不一致及Ⅱ~Ⅳ度急性GVHD呈正相关；多种疱疹病毒感染与HLA不全相合、非血缘供者及Ⅱ~Ⅳ度急性GVHD呈正相关。

结论

HSCT前后存在多种疱疹病毒感染，HLA不全相合、非血缘供者和Ⅱ~Ⅳ度急性GVHD与移植后多种疱疹病毒感染存在一定的相关性。

The impact of alternative donor types on viral infections in pediatric hematopoietic stem cell transplantation

Viral infections remain one of the most important complications following allogeneic HSCT. Few reports compare virus infection between different donor types in pediatric patients. We retrospectively analyzed viral infections and the outcome of one hundred and seventy-one pediatric patients (median 7.38 years) who underwent allogeneic HSCT from matched related donor (MRD, n = 71), 10 of 10 HLA allele-matched unrelated donors (MUD1; n = 29), 9 of 10 HLA allele-matched unrelated donors (MUD2; n = 40), and haploidentical donors (n = 31). PCR screening for BK virus, adenovirus, Epstein-Barr virus, parvovirus B19, human herpesvirus 6, and CMV were performed routinely weekly. Infections between 0-30, 31-100, and 101 days-2 years were identified separately. BK virus and CMV reactivations were significantly low in MRD transplant patients (P = .046 and P < .0001, respectively), but incidences of all virus infections between MUD1, MUD2, and haplo-HSCT were found statistically not different. The OS was found to be affected by having one or multiple virus infection (P = .04 and P = .0008). Despite antiviral prophylaxis and treatments, post-transplant viral infections are associated with reduced overall survival. Haplo-HSCT is comparable with MUD transplantation in the setting of viral infections. A larger study group and prospective studies are needed to confirm this observation.

Neurological complications of hematopoietic cell transplantation in children and adults

Hematopoietic cell transplantation (HCT) is widely performed for neoplastic and non-neoplastic diseases. HCT involves intravenous infusion of hematopoietic progenitor cells from human leukocyte antigen (HLA)-matched donor (allogeneic) or from the patient (autologous). Before HCT, the patient is prepared with high dose chemotherapy and/or radiotherapy to destroy residual malignant cells and to reduce immunologic resistance. After HCT, chemotherapy is used to prevent graft rejection and graft versus host disease (GvHD). Neurological complications are related to the type of HCT, underlying disease, toxicity of the conditioning regimens, immunosuppression caused by conditioning regimens, vascular complications generated by thrombocytopenia and/or coagulopathy, GvHD and inappropriate immune response. In this review, neurological complications are presented according to time of onset after HCT: (1) early complications (in the first month) - related to harvesting of stem cells, during conditioning (drug toxicity, posterior reversible encephalopathy syndrome), related to pancytopenia, (2) intermediate phase complications (second to sixth month) - central nervous system infections caused by prolonged neutropenia and progressive multifocal leukoencephalopathy due to JC virus, (3) late phase complications (after sixth month) - neurological complications of GvHD, second neoplasms and relapses of the original disease.

Viral surveillance using PCR during treatment of AML and ALL

BACKGROUND

While viral surveillance of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus using PCR is routine in patients undergoing hematopoetic stem cell transplant and solid organ transplant, the utility in the nontransplant pediatric leukemia population is unknown. Our institution screens patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) for viral DNAemia by PCR as part of clinical care.

PROCEDURE

This retrospective chart review included patients treated for newly diagnosed or relapsed AML or ALL between April 2010 and September 2014. We retrieved data for viral PCR screening, detection and quantification, duration of positivity, and prophylaxis or treatment.

RESULTS

One hundred eleven patients were included in analyses. Forty (36.0%) had at least one blood PCR positive for EBV, CMV, or adenovirus. Patients with ALL had significantly higher rates of persistent viral detection and treatment than those with AML (P < 0.02, P < 0.01, respectively). International patients had significantly higher rates of viral detection (P < 0.01), persistence (P < 0.01), any treatment (P < 0.03), and antiviral treatment (P < 0.01); 16.9% of patients who received intravenous immunoglobulin (IVIG) prophylactically had viral detection compared to 63% of patients who did not receive prophylactic IVIG (P = 0.0008).

CONCLUSIONS

Patients with ALL were more susceptible than those with AML to viral reactivation that was persistent or resulted in treatment. Patients with relapsed ALL, refractory ALL, or infantile ALL are most likely to benefit from asymptomatic screening for CMV and adenovirus. International patients are at higher risk for reactivation and may merit screening. EBV reactivation was not significant and does not warrant screening.

The cumulative burden of double-stranded DNA virus detection after allogeneic HCT is associated with increased mortality

Strategies to prevent active infection with certain double-stranded DNA (dsDNA) viruses after allogeneic hematopoietic cell transplantation (HCT) are limited by incomplete understanding of their epidemiology and clinical impact. We retrospectively tested weekly plasma samples from allogeneic HCT recipients at our center from 2007 to 2014. We used quantitative PCR to test for cytomegalovirus, BK polyomavirus, human herpesvirus 6B, HHV-6A, adenovirus, and Epstein-Barr virus between days 0 and 100 post-HCT. We evaluated risk factors for detection of multiple viruses and association of viruses with mortality through day 365 post-HCT with Cox models. Among 404 allogeneic HCT recipients, including 125 cord blood, 125 HLA-mismatched, and 154 HLA-matched HCTs, detection of multiple viruses was common through day 100: 90% had ≥1, 62% had ≥2, 28% had ≥3, and 5% had 4 or 5 viruses. Risk factors for detection of multiple viruses included cord blood or HLA-mismatched HCT, myeloablative conditioning, and acute graft-versus-host disease (P values < .01). Absolute lymphocyte count of <200 cells/mm³ was associated with greater virus exposure on the basis of the maximum cumulative viral load area under the curve (AUC) (P = .054). The maximum cumulative viral load AUC was the best predictor of early (days 0-100) and late (days 101-365) overall mortality (adjusted hazard ratio [aHR] = 1.36, 95% confidence interval [CI] [1.25, 1.49], and aHR = 1.04, 95% CI [1.0, 1.08], respectively) after accounting for immune reconstitution and graft-versus-host disease. In conclusion, detection of multiple dsDNA viruses was frequent after allogeneic HCT and had a dose-dependent association with increased mortality. These data suggest opportunities to improve outcomes with better antiviral strategies.

Antiviral prophylaxis for preventing herpes zoster in hematopoietic stem cell transplant recipients: A systematic review and meta-analysis

The optimal duration of prophylaxis for the varicella-zoster virus following hematopoietic stem cell transplantation (HSCT) remains unclear. The purpose of this study was to systematically review the available literature to determine the optimal duration of antiviral prophylaxis for preventing herpes zoster (HZ) in allogeneic and autologous HSCT recipients. The MEDLINE and EMBASE databases were searched to identify relevant studies. The relative risk (RR) of HZ was calculated using fixed effects or random effects models depending on heterogeneity across the included studies. We analyzed six observational studies comprising a total of 3420 patients. In all HSCT recipients, the overall incidence of HZ in the prophylaxis group and the control group was 7.8% and 25.6%, respectively, with a pooled RR of 0.31 (95% CI, 0.26-0.37). The incidence of HZ in the subgroup wherein prophylaxis was given for at least 1 year and in the subgroup wherein prophylaxis was given for less than 1 year was 2.1% and 15.4%, respectively, with a pooled RR of 0.23 (95% CI, 0.04-1.39). Taken together, our results demonstrate that antiviral prophylaxis can significantly reduce HZ in HSCT recipients, and suggests that long-term prophylaxis given for at least 1 year may be recommended for better preventive effects.

New 4-Acyl-1-phenylaminocarbonyl-2-phenylpiperazine Derivatives as Potential Inhibitors of Adenovirus Infection. Synthesis, Biological Evaluation, and Structure-activity Relationships

The search for human adenovirus (HAdV)-specific antiviral drugs for the treatment of HAdV infections in immunocompromised patients continues to be a challenging goal for medicinal chemistry. Here, we report the synthesis, biological evaluation, and structure-activity relationships of a small molecules library. We have identified six phenylpiperazine derivatives that significantly inhibited HAdV infection. These six compounds showed the capacity to block HAdV and, in addition, human cytomegalovirus (HCMV) replications at low micromolar concentration, with little or no cytotoxicity. On the basis of our biological studies, these molecules block HAdV and HCMV infections in different phases of their life cycle, providing potential candidates for the development of a new family of antiviral drugs for the treatment of infections by DNA viruses.

Unrelated donor hematopoietic stem cell transplantation for the treatment of non-malignant genetic diseases: An alemtuzumab based regimen is associated with cure of clinical disease; earlier clearance of alemtuzumab may be associated with graft rejection

Hematopoietic stem cell transplantation (HSCT) with matched unrelated donors (MUD), offers potentially curative therapy for patients with non-malignant genetic diseases. In this pilot study conducted from 2006 to 2014, we report the outcomes of 15 patients with non-malignant genetic diseases who received a myeloablative regimen with a reduced cyclophosphamide dose, adjunctive serotherapy and MUD HSCT [intravenous alemtuzumab (52 mg/m(2) ), busulfan (16 mg/kg), fludarabine (140mg/m(2) ), and cyclophosphamide (105 mg/kg)]. Graft-versus-host-disease (GVHD) prophylaxis consisted of tacrolimus/cyclosporine and methylprednisolone. Median (range) time to neutrophil engraftment (>500 cells/µL) and platelet engraftment (>20,000/mm(3) ) were 15 (12-28) and 25 (17-30) days, respectively. At a median follow-up of 2 (0.2-5.4) years, the overall survival (OS) was 93.3% (95% CI: 0.61-0.99) and disease-free survival (DFS) was 73.3% (95% CI: 0.44-0.89). Among this small sample, earlier alemtuzumab clearance was significantly associated with graft rejection (P = 0.047), earlier PHA response (P = 0.009) and a trend toward earlier recovery of recent thymic emigrants (RTE) (P = 0.06). This regimen was associated with durable donor engraftment and relatively low rates of regimen related toxicity (RRT); future alemtuzumab pharmacokinetic studies may improve outcomes, by allowing targeted alemtuzumab clearance to reduce graft rejection and promote more rapid immune reconstitution.

Fulminant adenovirus hepatitis after hematopoietic stem cell transplant: Retrospective real-time PCR analysis for adenovirus DNA in two cases

BACKGROUND

Viral infection is one of the major causes of mortality in patients undergoing hematopoietic stem cell transplant (HSCT). Systemic infection of adenovirus (AdV) has emerged as a not uncommon viral infection with significant morbidity and mortality as with cytomegalovirus and Epstein-Barr virus infection. Routine surveillance for these viruses has become a clinical practice and subsequent preemptive therapy improves patients' outcomes; however, the effectiveness of preemptive therapy for AdV has not been fully investigated in patients with a lethal form of AdV infection.

METHODS

Sequential AdV loads were retrospectively analyzed in children with fulminant AdV hepatitis after HSCT.

RESULTS

The AdV DNA became detectable (1 × 10(4) copies/mL) as early as 2 weeks after HSCT. These levels reached >1 × 10(8) copies/mL at the onset of fulminant hepatitis. However, we determined that γ-glutamyltransferase levels were elevated to >100 IU/L at least 2 weeks before the diagnosis of hepatitis.

CONCLUSIONS

Our observation raises the possibility that elevated γ-glutamyltransferase could be a sentinel marker for AdV hepatitis, which prompts elaborated monitoring of AdV load and targeted treatment.

Activity of broad-spectrum T cells as treatment for AdV, EBV, CMV, BKV, and HHV6 infections after HSCT

It remains difficult to treat the multiplicity of distinct viral infections that afflict immunocompromised patients. Adoptive transfer of virus-specific T cells (VSTs) can be safe and effective, but such cells have been complex to prepare and limited in antiviral range. We now demonstrate the feasibility and clinical utility of rapidly generated single-culture VSTs that recognize 12 immunogenic antigens from five viruses (Epstein-Barr virus, adenovirus, cytomegalovirus, BK virus, and human herpesvirus 6) that frequently cause disease in immunocompromised patients. When administered to 11 recipients of allogeneic transplants, 8 of whom had up to four active infections with the targeted viruses, these VSTs proved safe in all subjects and produced an overall 94% virological and clinical response rate that was sustained long-term.

Viral infections in acute graft-versus-host disease: a review of diagnostic and therapeutic approaches

BACKGROUND

While immunosuppressive therapy for acute graft-versus-host disease (aGVHD) advances, viral reactivation has been found to be an increasingly common complication in these patients. Dermatologists may often be consulted on inpatient services for evaluation.

OBJECTIVE

We investigated the literature for the role of viral infections in aGVHD and review the current evidence regarding management.

METHODS

Articles in the public domain regarding aGVHD, cytomegalovirus, Epstein-Barr virus, varicella zoster virus, hepatitis viruses, parvovirus B19, and respiratory viruses were included.

RESULTS

Dermatologic findings vary between different viral antigens, and some infections may be a marker for the development of aGVHD or worsen prognosis.

LIMITATIONS

The heterogeneous cohorts of the studies reviewed often preclude direct comparison between results.

CONCLUSION

The relationship between viral reactivation and aGVHD may be bidirectional and is worthy of further exploration. Additional studies are needed to determine appropriate prophylaxis and treatment.

Inhibition of adenovirus replication by a trisubstituted piperazin-2-one derivative

The number of disseminated adenovirus (Ad) infections continues to increase mostly due to the growing use of immunosuppressive treatments. Recipients of solid organ or hematopoietic stem cell transplants, mainly in pediatric units, exhibit a high morbidity and mortality due to these infections. Unfortunately, there are no Ad-specific antiviral drugs currently approved for medical use. To address this situation, we used high-throughput screening (HTS) of synthetic small molecule libraries to identify compounds that restrict Ad infection. Among the more than 25,000 compounds screened, we identified a hit compound that significantly inhibited Ad infection. The compound (15D8) is a trisubstituted piperazin-2-one derivative that showed substantial antiviral activity with little or no cytotoxicity at low micromolar concentrations. Compound 15D8 selectively inhibits Ad DNA replication in the nucleus, providing a potential candidate for the development of a new class of antiviral compounds to treat Ad infections.

Prospective, comprehensive, and effective viral monitoring in Cuban children undergoing solid organ transplantation

PURPOSE

In Cuba, viral monitoring in the post-transplant period was not routinely performed. The aim of this research is to identify the most frequent viruses that affect transplanted Cuban children, by implementing a viral follow-up during the post-transplant period.

METHODS

The study population included all Cuban pediatric patients who underwent solid organ transplantation (SOT) between November 2009 and December 2012. A total of 34 transplanted pediatric patients of kidney (n = 11) and liver (n = 23) were prospectively monitored during a 34-week period for viral DNAemia and DNAuria by simultaneous detection of cytomegalovirus (CMV), Epstein-Barr virus, herpes simplex virus type 1 and 2, varicella zoster virus, human herpesvirus 6, human adenovirus, and polyomaviruses (BKV and JCV) using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Viral genome of at least one virus was detected in 21 of 34 recipients, 18 patients excreted virus in urine while 12 presented DNAemia. CMV (41.2%) and BKV (35.3%) were the most frequent viruses detected during the follow-up. CMV was the virus mainly associated with clinical symptoms and DNAemia. Its excretion in urine (with cut off value of 219 copies/mL) was associated with detection in plasma (p < 0.001); furthermore, CMV viruria was predictive of CMV viremia (OR:8.4, CI:2.4-29.1, p = 0.001). There was no association between high viral load and clinical complications, due to the prompt initiation of preemptive ganciclovir.

CONCLUSION

This comprehensive viral monitoring program effectively prevents the development of critical viral disease, thus urge the implementation of qRT-PCR as routine for viral monitoring of transplanted Cuban organ recipients.

Safety and clinical efficacy of rapidly-generated trivirus-directed T cells as treatment for adenovirus, EBV, and CMV infections after allogeneic hematopoietic stem cell transplant

Adoptive transfer of virus-specific T cells can prevent and treat serious infections with Epstein-Barr virus (EBV), cytomegalovirus (CMV), and adenovirus (Adv) after allogeneic hematopoietic stem cell transplant. It has, however, proved difficult to make this approach widely available since infectious virus and viral vectors are required for T cell activation, followed by an intensive and prolonged culture period extending over several months. We now show that T cells targeting a range of viral antigens derived from EBV, CMV, and Adv can be reproducibly generated in a single culture over a 2-3-week period, using methods that exclude all viral components and employ a much-simplified culture technology. When administered to recipients of haploidentical (n = 5), matched unrelated (n = 3), mismatched unrelated (n = 1) or matched related (n = 1) transplants with active CMV (n = 3), Adv (n = 1), EBV (n = 2), EBV+Adv (n = 2) or CMV+Adv (n = 2) infections, the cells produced complete virological responses in 80%, including all patients with dual infections. In each case, a decrease in viral load correlated with an increase in the frequency of T cells directed against the infecting virus(es); both immediate and delayed toxicities were absent. This approach should increase both the feasibility and applicability of T cell therapy. The trial was registered at www.clinicaltrials.gov as NCT01070797.

Umbilical cord blood transplantation: review of factors affecting the hospitalized patient

The use of umbilical cord blood (UCB) as a stem cell donor source has dramatically increased over the last 2 decades. Patients undergoing UCB transplantation share medical management issues with patients receiving a hematopoietic stem cell transplantion using adult donor sources (peripheral blood stem cells or bone marrow stem cells) and may also have more complex medical issues that appear to be related to delayed immune recovery from UCB-derived stem cells. The interface with critical care providers is likely to occur in the transplant and posttransplant setting. Patients may experience UCB infusion reactions that range from mild to rarely severe. Following transplant, patients are transfusion dependent for long periods due to the prolonged engraftment of UCB cells. They are at high risk of infection, particularly viral. Once engrafted, UCB transplant patients have a lower rate of graft versus host disease compared to other donor sources. Some of the other complications that are seen in patients undergoing UCB transplant are posttransplant lymphoproliferative disease, diffuse alveolar hemorrhage, and posterior reversible encephalopathy will also be discussed.

Respiratory viral infections in pediatric solid organ and hematopoietic stem cell transplantation

Respiratory viruses are common in children, including pediatric recipients of both solid organ transplantation and hematopoietic stem cell transplantation. The prevalence and risk factors in each of these groups are reviewed. Furthermore, associated morbidity and mortality in pediatric transplant recipients with respiratory viral infections are addressed. The literature on specific prevention and treatment options for respiratory syncytial virus, adenovirus, influenza, and other respiratory viruses in pediatric solid organ and hematopoietic stem cell transplant recipients is reported.

Molecular diagnosis and management of viral infections in hematopoietic stem cell transplant recipients

Viral infections after allogeneic hematopoietic stem cell transplantation (HSCT) are important complications associated with high morbidity and mortality. In this setting, reactivations of persisting latent viral pathogens from donor and/or recipient cells play a central role whereas the sterile environment of transplant units renders new infections less likely. The viruses currently regarded as most relevant in the HSCT setting include particularly the herpes virus family--specifically cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6)--as well as human adenoviruses (AdVs) and the polyoma virus BK (BKV). Timely detection and monitoring of virus copy numbers are prerequisites for successful preemptive treatment approaches. Pre- and post-transplant surveillance by sensitive and quantitative molecular methods has therefore become an essential part of the diagnostic routine. In this review, we discuss diagnostic aspects and the clinical management of the most important viral infections in HSCT recipients, with a focus on pediatric patients.

Rapidly generated multivirus-specific cytotoxic T lymphocytes for the prophylaxis and treatment of viral infections

Severe and fatal viral infections remain common after hematopoietic stem cell transplantation. Adoptive transfer of cytotoxic T lymphocytes (CTLs) specific for Epstein–Barr virus (EBV), cytomegalovirus (CMV), and adenoviral antigens can treat infections that are impervious to conventional therapies, but broader implementation and extension to additional viruses is limited by competition between virus-derived antigens and time-consuming and laborious manufacturing procedures. We now describe a system that rapidly generates a single preparation of polyclonal (CD4⁺ and CD8⁺) CTLs that is consistently specific for 15 immunodominant and subdominant antigens derived from 7 viruses (EBV, CMV, Adenovirus (Adv), BK, human herpes virus (HHV)-6, respiratory syncytial virus (RSV), and Influenza) that commonly cause post-transplant morbidity and mortality. CTLs can be rapidly produced (10 days) by a single stimulation of donor peripheral blood mononuclear cells (PBMCs) with a peptide mixture spanning the target antigens in the presence of the potent prosurvival cytokines interleukin-4 (IL4) and IL7. This approach reduces the impact of antigenic competition with a consequent increase in the antigenic repertoire and frequency of virus-specific T cells. Our approach can be readily introduced into clinical practice and should be a cost-effective alternative to common antiviral prophylactic agents for allogeneic hematopoietic stem cell transplant (HSCT) recipients.

Overview of the diagnosis of cytomegalovirus infection

Cytomegalovirus (CMV) is recognized as the most common congenital viral infection in humans and an important cause of morbidity and mortality in immunocompromised hosts. This recognition of the clinical importance of invasive CMV disease in the setting of immunodeficiency and in children with congenital CMV infection has led to the development of new diagnostic procedures for the rapid identification of CMV. Diagnosis of acute maternal CMV infection by the presence of immunoglobulin (Ig)M and low-avidity IgG requires confirmation of fetal infection, which is typically performed using polymerase chain reaction (PCR) assays for CMV on amniotic fluid. Viral culture of the urine and saliva obtained within the first two weeks of life continues to be the gold standard for diagnosis of congenitally-infected infants. PCR assays of dried blood spots from newborns have been shown to lack sufficient sensitivity for the identification of most neonates with congenital CMV infection for universal screening purposes. However, saliva PCR assays are currently being assessed as a useful screening method for congenital CMV infection. In the immunocompromised host, newer rapid diagnostic assays, such as phosphoprotein 65 antigenemia and CMV real-time PCR of blood or plasma have allowed for preemptive treatment, reducing morbidity and mortality. However, lack of standardized real-time PCR protocols hinders the comparison of data from different centers and the development of uniform guidelines for the management of invasive CMV infections in immunocompromised individuals.