Cytomegalovirus infection in pediatric allogenic hematopoietic stem cell transplantation. A single center experience

Time-dependent analysis of the impact on early cytomegalovirus reactivation of HLA mismatch and acute graft-versus-host disease after allogeneic hematopoietic cell transplantation from related donors in acquired aplastic anemia

Cytomegalovirus (CMV) reactivation is an important issue in allogeneic hematopoietic cell transplantation (HCT). The incidence of early CMV reactivation is notably high in HLA-mismatched HCT. However, the interactions between HLA mismatch and acute graft-versus-host disease (aGvHD), a time-dependent event, make it methodologically challenging to evaluate the independent impact on CMV reactivation of the two variables. We retrospectively analyzed 355 patients with acquired aplastic anemia who received related donor transplants using a unified antithymocyte globulin-based platform. Patients were divided into group 1 (6/6 HLA match), group 2 (1-2/6 HLA allelic mismatch), and group 3 (3/6 HLA allelic mismatch). The impact of covariates was analyzed through two models: (1) time-dependent Cox and (2) dynamic landmarking analysis. The time-dependent Cox model showed that the HLA mismatch of 3/6 alleles (hazard ratio (HR) =1.852, P = .004) and aGvHD (HR = 1.009, P = .019) were independent risk factors for CMV reactivation. With the dynamic landmarking analysis, a higher HLA disparity correlated to increased early CMV reactivation (HR = 1.606, P = .001) at all time points. Developing aGvHD following HCT was generally associated with a higher incidence of CMV reactivation (HR = 1.623, P = .013), though its impact decreased with successive later landmark time points. In conclusion, our data suggest that the higher HLA disparity and aGvHD increases susceptibility to early CMV reactivation. In particular, the dynamic landmarking analysis demonstrated the time-varying effect of aGvHD on CMV reactivation, and HLA mismatch showed a profound impact over time following HCT.

The Impact of High CMV Viral Load and Refractory CMV Infection on Pediatric HSCT Recipients with Underlying Non-Malignant Disorder

Hematopoietic stem cell transplantation (HSCT) is a curative therapy for an increasing number of nonmalignant indications. Its use is restricted by severe transplant-related complications, including CMV infection; despite various prophylactic and therapeutic strategies, CMV reactivation has remarkable morbidity and mortality. The analysis included 94 children with nonmalignant disorder who underwent allogeneic HSCT in the Department of Pediatric Hematology, Oncology, and Bone Marrow Transplantation in Wrocław during years 2016–2020. Twenty-seven (29%) children presented with CMV infection, including ten (10/27; 37%) with high level CMV viremia (10,000 copies/mL). Six patients experienced subsequent CMV reactivation. The first-line ganciclovir-based (GCV) treatment was insufficient in 40% (11/27) of children. Overall survival (OS) was significantly lower in children with high CMV viremia compared to those with low levels/no CMV [1yrOS High CMV = 0.80 (95% CI 0.41–0.95) vs. 1yrOS others = 0.96 (95% CI 0.89–0.99)]. Similarly, patients with resistant and recurrent infections had greater risk of death. CMV reactivation at any level relevantly prolonged the hospital stay. CMV reactivation with high viremia load and resistant/recurrent CMV infections lead to a significant decrease in OS in children with nonmalignant disorders treated with HSCT. Our data proves there is an urgent need to introduce an effective anti-CMV prophylaxis in this cohort of patients.

Risk factors and incidence of cytomegalovirus viremia and disease in pediatric patients with allogeneic hematopoietic stem cell transplantation: An 8-year single-center experience in Latin America

BACKGROUND

Cytomegalovirus infection represents a significant cause of morbidity and mortality after hematopoietic stem cell transplantation. This study aimed to evaluate the incidence of viremia and disease due to cytomegalovirus and the risk factors in pediatric patients with hematopoietic stem cell transplantation in our institution.

METHODS

This was a retrospective cohort of patients under 19 years of age who underwent allogeneic hematopoietic stem cell transplantation due to any indication between 2012 and 2019. The analysis included the diagnosis of cytomegalovirus viremia or disease during post-transplant follow-up, evaluation of risk factors, and outcomes. The statistical analysis included univariate and multivariate analyses, and the cumulative incidence of cytomegalovirus viremia was determined by the Kaplan-Meier method using STATA 14 statistical software.

RESULTS

A total of 182 transplants were included. At 100 days, the cumulative incidence of cytomegalovirus viremia was 70.5%, and that of cytomegalovirus disease was 4.7%. Overall survival at 2 years was 74%, and event-free survival was 64%. The remaining demographic characteristics were not predictors of infection. There was no association between viremia and relapse or survival of the patients. Higher mortality was noted in cytomegalovirus disease.

CONCLUSIONS

During the study period, the incidence of cytomegalovirus disease was similar to that of other pediatric reports, but the incidence of viremia was higher. Pre-emptive therapy has diminished disease rates and death due to infection. Viral load cutoff points should be standardized to guide treatment and avoid myelotoxicity.

Incidence of CMV Infection and Disease and Adverse Events Associated with Antiviral Therapy in a Retrospective Cohort of Allogeneic Hematopoietic Cell Transplant Recipients at an Academic Children's Hospital

BACKGROUND

Cytomegalovirus (CMV) is a significant source of morbidity and mortality among transplant recipients; the epidemiology is less understood in pediatric hematopoietic cell transplantation (HCT) cohorts. Furthermore, there is a paucity of data related to CMV prophylactic and preemptive strategies.

METHODS

A single-center retrospective observational cohort of allogeneic HCT recipients at the Children's Hospital of Philadelphia January 1, 2004-December 31, 2017 was constructed. Subjects were followed for 180 days after transplant to determine whether they had CMV infection or disease. Data on antiviral therapy were collected as were outcomes of CMV disease and adverse events (AEs) related to the antiviral therapy.

RESULTS

Between January 2004 and March 2017, 345 allogeneic HCTs in 333 patients undergoing CMV surveillance testing were identified. CMV DNAemia was detected during the 180-day follow-up in 89 (25.8%) HCTs. CMV recipient-positive transplants were most likely to have CMV infection (47%). Infection rates were high for those receiving a CMV-specific prophylaxis regimen (50%). CMV DNAemia progressed to CMV disease 11.2% of the time. Of 224 subjects receiving CMV-specific prophylaxis, 19.2% experienced ≥1 AE. Of 53 receiving preemptive therapy during any CMV DNAemia episode, 32.1% experienced ≥1 AE.

CONCLUSIONS

CMV infection is common in pediatric allogeneic HCT recipients. The CMV-specific prophylaxis regimen employed in this cohort did not effectively prevent DNAemia, progression to CMV disease was uncommon, and AEs from prophylaxis and preemptive therapy were frequent. Novel approaches that reduce the impact of CMV on pediatric allogeneic HCT recipients are needed.

Infectious complications in pediatric allogeneic hematopoietic stem cell transplantation recipients-A retrospective clinical and epidemiological cohort study

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is an important therapeutic strategy for several hematologic diseases. In the absence of a matched related donor, allogeneic HSCT has been associated with increased risk of infectious complications. Here, we present the clinical and epidemiological characteristics of early infectious complications in children undergoing HSCT from Southern Brazil.

METHODS

This is a retrospective unicentric cohort study of infections in all children receiving their first HSCT during the period between 2010 and 2017.

RESULTS

Data from 292 patients were analyzed; bone marrow failures (52.7%) comprised most of the baseline diagnosis. Bone marrow (BM) was the stem cell source in 254 (87%), followed by cord blood (CB) in 34 (11.6%) children. The use of alternative donors (77.8%) and presence of acute graft-vs-host disease (GVHD) (23.6%) were associated with an increased risk of viral and fungal infection. Bacterial infection was observed in 79 patients (27%); 220 patients (75.3%) were diagnosed with viral infection, and 35 patients (12%) developed fungal infection. The presence of fungal disease together with the presence of multiple infections during follow-up was associated with an increased risk of death (P < .001).

CONCLUSIONS

The clinical profile of HSCT-related infections in this cohort suggests that prognosis in allogeneic HSCT is influenced by the source of stem cells (CB having worse prognosis), presence of acute GVHD and complications arising from fungal infections. The appropriate management of these factors has the potential to improve the overall prognosis rates in pediatric allogeneic HSCT recipients.

Cytomegalovirus viremia and resistance patterns in immunocompromised children: An 11-year experience

We noted a recent increase in number of immunocompromised children with CMV viremia at our institution. The purpose of this study was to determine the frequency of CMV viremia in this population and evaluate factors associated with drug-resistant mutations. A retrospective review of immunocompromised hosts, 0-21 years of age, who had CMV viremia during 2007-2017. CMV viremia was detected using PCR assays. Genetic mutation assays were performed using PCR sequencing of the phosophotransferase UL 97 gene and the polymerase UL54 gene of CMV using Quest Diagnostics (San Juan Capistrano, CA, USA) or ARUP Labs (Salt Lake City, UT, USA). Thirty-one patients were identified, including 10 (32%) during the last 2 years. Of the 31 patients, 18 had hematopoietic stem cell transplantation (HSCT), 5 had primary immunodeficiency, 4 had malignancies, 3 had heart transplantation and 1 had new Human Immunodeficiency virus (HIV) infection. Antiviral resistance testing was performed on isolates from seven patients: five with persistent viremia (>1 mo), and two prior to starting antiviral therapy. Resistance was identified in three patients' isolates: two with common variable immunodeficiency (CVID) and one with recurrent Hodgkin's lymphoma who had undergone autologous HSCT. The two patients with CVID had chronic diarrhea and malabsorption and had received prolonged oral valganciclovir courses prior to emergence of resistance. The patient with Hodgkin's lymphoma had received a prolonged IV ganciclovir course. All three tested positive for UL97 mutation and two had both UL97 and UL54 gene mutations. Majority of our patients (21/31) with CMV viremia were transplant recipients and ganciclovir resistance developed in 10%. Two had intestinal malabsorption. Treatment with oral valganciclovir should be avoided in patients with poor gut absorption as that may increase the risk of resistance.

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

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

Maternal and child human leukocyte antigens in congenital cytomegalovirus infection

Congenital Cytomegalovirus infection (cCMV) is the most common cause of congenital infections worldwide causing permanent long-term impairment (LTI). cCMV immunopathogenesis remains largely unknown due to the complex interplay between viral, maternal, placental and child factors. The aim of this study was to determine the possible role of particular HLA antigens, of the number of HLA mismatches (mm) and non-inherited maternal antigens (NIMAs) in a large retrospective nation-wide cohort of children with cCMV and their mothers. HLA Class I (HLA-A, HLA-B and HLA-C) and HLA Class II (HLA-DR and HLA-DQ) were assessed in 96 mother-child pairs in relation to a control group of 5604 Dutch blood donors, but no significant differences were observed. Next, although these HLA antigens could not be assessed in relation to symptoms at birth, nor to LTI, due to the low number of cases, they could be evaluated in relation to CMV viral load. HLA-DRB1*04, and potentially HLA-B*51, was shown to have a protective role in the children as its frequency was increased in the low viral load group compared to the high viral load group, and this remained significant after correction. The number of HLA mm and of NIMAs were not associated to symptoms at birth nor to LTI or viral load. In conclusion, although none of the HLA alleles could be put forward as prognostic marker for long-term outcome, our findings give useful insights into cCMV pathogenesis, and identify potential HLAs that correlate with a better viral control.

Effect of FOXP3 polymorphism on the clinical outcomes after allogeneic hematopoietic stem cell transplantation in pediatric acute leukemia patients

Forkhead BOX P3 (FOXP3) polymorphisms have recently been investigated as candidate risk factors in several tumors and autoimmune diseases. This study aims to evaluate the potential influence of FOXP3 rs3761548 polymorphism in the donor on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 171 patients were enrolled for this study and genotyped using direct sequencing. Patients with rs3761548 CC genotype had higher incidence of hepatic veno-occlusive disease (HVOD) and cytomegalovirus (CMV) infection than that of the individuals with AA or AC genotype (P=0.011, P=0.023). Treatment-related mortality (TRM) rate of patients with AA or AC genotype was lower than that of the patients with CC genotype (P=0.044) resulting in a difference in overall survival (OS). However, there was no difference in graft-versus-host disease (GVHD) relapse or blood stream infection (BSI), depending on the genotype at rs3761548 locus. In multivariate analysis, CC genotype showed as a risk factor in the development of HVOD and CMV infection, with low OS. In conclusion, this is the first report on FOXP3 rs3761548 SNP in allo-HSCT and we suggest that this SNP be considered a candidate marker for predicting the development of HVOD and CMV infection after allo-HSCT.

Characterization of multiple cytomegalovirus drug resistance mutations detected in a hematopoietic stem cell transplant recipient by recombinant phenotyping

Cytomegalovirus resistance to antivirals is a major problem in transplant recipients. We evaluated the impact of five mutations (A594V, L595F, and E655K in the UL97 gene and V526L and E756K in the UL54 gene), detected in a blood sample from a stem cell transplant recipient, on drug susceptibilities and replicative capacities of recombinant viruses.