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

Adenovirus infections after allogeneic hematopoietic cell transplantation in children and adults: a study from the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

The objective of the study was the analysis of clinical types, outcomes, and risk factors associated with the outcome of adenovirus (ADV) infection, in children and adults after allo-HCT. A total number of 2529 patients (43.9% children; 56.1% adults) transplanted between 2000 and 2022 reported to the EBMT database with diagnosis of ADV infection were analyzed. ADV infection manifested mainly as viremia (62.6%) or gastrointestinal infection (17.9%). The risk of 1-year mortality was higher in adults (p = 0.0001), and in patients with ADV infection developing before day +100 (p < 0.0001). The 100-day overall survival after diagnosis of ADV infections was 79.2% in children and 71.9% in adults (p < 0.0001). Factors contributing to increased risk of death by day +100 in multivariate analysis, in children: CMV seropositivity of donor and/or recipient (p = 0.02), and Lansky/Karnofsky score <90 (p < 0.0001), while in adults: type of ADV infection (viremia or pneumonia vs gastrointestinal infection) (p = 0.0004), second or higher HCT (p = 0.0003), and shorter time from allo-HCT to ADV infection (p = 0.003). In conclusion, we have shown that in patients infected with ADV, short-term survival is better in children than adults. Factors directly related to ADV infection (time, clinical type) contribute to mortality in adults, while pre-transplant factors (CMV serostatus, Lansky/Karnofsky score) contribute to mortality in children.

Retrospective Evaluation of Cystatin C as a Measure of Renal Function in Pediatric Hematopoietic Stem Cell Transplant Patients Receiving Foscarnet for Cytomegalovirus Reactivation

BACKGROUND

Cytomegalovirus (CMV) infection following allogeneic hematopoietic cell transplantation has considerable morbidity and mortality, and foscarnet is a treatment option that requires renal dose adjustment. Serum creatinine (SCr)-based estimated glomerular filtration rate (eGFR) equations are used to estimate renal function for patients receiving foscarnet, but cystatin C (cysC) has been shown as a possible alternative. Data examining cysC-based eGFR in this population is sparse. Our primary objective was to evaluate outcomes of patients treated with foscarnet dosed utilizing cysC-based eGFR versus SCr-based eGFR.

METHODS

We analyzed patients on the transplantation and cellular therapies service at Memorial Sloan Kettering Kids from January 2011 to September 2021 who received allogeneic hematopoietic cell transplantation and ≥14 days of foscarnet for CMV infection. Patients with cysC-based eGFR were compared to a historical cohort of patients who only had SCr-based eGFR. Outcomes included time to CMV clearance, death or change in anti-CMV therapy. Cumulative incidence curves and cause-specific hazards model were used for analysis.

RESULTS

In 61 analyzed patients, no differences were found between the cohorts in cumulative incidence of change in anti-CMV therapy ( P = 0.17) or death ( P = 0.69). After adjustment for multiple confounders, patients in the SCr cohort seemed to have a higher chance of CMV clearance compared with the cysC cohort, but the difference was not statistically significant (hazard ratio = 2.42, P = 0.089). Patients who received corticosteroids appeared to have lower incidence of CMV clearance ( P = 0.056).

CONCLUSIONS

We did not find differences in outcomes when dosing foscarnet using cysC versus SCr for treatment of CMV infection.

Adenovirus infection in adult patients undergoing allogeneic hematopoietic stem cell transplant: Incidence, clinical management, and outcome

BACKGROUND

Adenovirus infection (ADVi) is an emergent complication in adult patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is associated with poor outcome. Available data on risk factors and optimal management of ADVi in adult allo-HSCT recipients are limited, and recommendations on monitoring and pre-emptive therapy are mainly based on pediatric data.

METHODS

In this single-center, retrospective study, we reported all cases of positive ADV-DNA from adult patients undergoing allo-HSCT in the period 2014-2019. The study aimed to describe the incidence of ADVi at day +180 post-transplant. Secondly to describe timing, clinical presentation, risk factors, and outcome of ADVi and to analyze the application of a screening strategy in our cohort.

RESULTS

In 445 allo-HSCT recipients, the day +180 incidence was: 9% (39/445) for ADVi, 5% (24/445) for ADV viremia (ADVv), and 3% (15/445) for localized ADVi. The median time to ADVi was 65 (IQR 19; 94) days after HSCT. ADVv-related mortality was 13% (3/24), all cases occurring with blood max-ADV-DNA > 10^3 cp/mL. Independent risk factors for ADVi were diagnosis of lymphoproliferative disease (p = .011) and acute graft-versus-host-disease (p = .021).

CONCLUSIONS

In our cohort, ADVi and ADVv were more frequent than previously reported. ADVv with max-ADV-DNA > 10^3 cp/mL was associated with ADV-related mortality, thus careful monitoring and early initiation of treatment are advisable.

Acute Myeloid Leukemia Post Cytotoxic Therapy in Breast Cancer Survivors-Over 23 Years of Single Center Analysis

Background: Acute myeloid leukemia post cytotoxic therapy (AML-pCT) among breast cancer (BC) survivors represents a life-threatening complication. This study aims to assess the clinical outcomes of AML-pCT post BC. Methods: An analysis of all AML patients treated at a single hematology center (2000-2023) was performed to select patients with AML-pCT post BC. We applied the 2022 ELN criteria to define the genetic risk. Results: Among 847 AML patients, 28 were diagnosed with AML-pCT following BC. Complex karyotype (CK) occurred in 23.8% of patients. The median overall survival (OS) was 40 months. The survival outcomes were better after allogenic hematopoietic stem cell transplantation (alloHCT) treatment compared to chemotherapy alone (median OS: 47 versus 7 months, p = 0.008). Patients demonstrating CK showed lower survival compared to those without CK (2-year OS: 25.0% versus 66.2%, p = 0.0048). The multivariable Cox proportional hazards regression model indicated that treatment with alloHCT emerged as a significant factor associated with improved OS. The treatment was associated with superior OS (HR = 0.07, 95% CI = 0.01-0.86, p = 0.04). Conclusions: Patients with AML-pCT following BC were characterized with the highest frequency of adverse genetic risk profiles and demonstrated worse survival rates. AlloHCT should be performed as early as possible in such patients. The growing need for studies on inherited cancer susceptibility underscores the importance of close AML-pCT development monitoring in BC survivors.

Infection With Saprochaete Clavata in Children After Hematopoietic Cell Transplantation

Septic shock is a very rare manifestation of invasive fungal disease (IFD) in children after allogeneic hematopoietic cell transplantation (allo-HCT). The objective of this paper is analysis of two cases of pediatric patients with IFD caused by Saprochaete clavata after allo-HCT. Literature data on this infection in children and its outcome were also summarized. Infection with Saprochaete clavate presenting with symptoms of septic shock was being reported in 4 children, and 2 of them survived the infection. In conclusion, with quick diagnosis and quick treatment, the outcome of therapy of infection with Saprochaete clavata was successful.

Infections and risk factors for infection-related mortality after pediatric allogeneic hematopoietic stem cell transplantation in Mexico: A single center retrospective study

OBJECTIVE

To identify the type of infections and risk factors for infection-related mortality (IRM) after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Retrospective cohort study of patients <16 years of age treated in 2010-2019 was conducted. Unadjusted hazard ratios (HR) and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CIs) were estimated using Cox regression. Cumulative incidence was calculated.

RESULTS

Data for 99 pediatric patients were analyzed. The myeloablative conditioning was the most used regimen (78.8%) and the hematopoietic stem cell source was predominantly peripheral blood (80.8%). Primary graft failure occurred in 19.2% of patients. Frequency of acute graft-versus-host disease was 46.5%. Total of 136 infectious events was recorded, the most common of which were bacterial (76.4%) followed by viral infection (15.5%) and then fungal infection (8.1%). The best predictors for infection subtypes where the following: a) for bacterial infection (the age groups of 10.1-15 years: aHR = 3.33; 95% CI: 1.62-6.85 and. >15 years: aHR = 3.34; 95% CI: 1.18-9.45); b) for viral infection (graft versus host disease: aHR = 5.36; 95% CI: 1.62-17.68), however, for fungal infection statistically significant predictors were not identified. Related mortality was 30% (n = 12). Increased risk for infection-related mortality was observed in patients with unrelated donor and umbilical cord stem cells recipients (HR = 3.12; 95% CI: 1.00-9.85).

CONCLUSIONS

Frequencies of infections and infection-related mortality appear to be similar to those reported. Unrelated donors and stem cells from umbilical cord recipients were associated with a high risk of mortality.

A Comparison Between the Perioperative Outcomes of Female Adolescent Idiopathic Scoliosis (AIS) Versus Adult Idiopathic Scoliosis (AdIS) Following Posterior Spinal Fusion: A Propensity Score Matching Analysis Involving 425 Patients

STUDY DESIGN

Retrospective propensity score matching (PSM) study.

OBJECTIVE

To investigate the perioperative outcomes comparing adolescent idiopathic scoliosis (AIS) and adult idiopathic scoliosis (AdIS) patients following posterior spinal fusion (PSF).

METHODS

425 female AIS and AdIS patients who were operated (between January 2015 to March 2020) using a dual attending surgeon strategy were stratified into G1 (AIS aged 10-16 years old) and G2 (AdIS > 20 years old). PSM analysis with one-to-one, nearest neighbor matching technique with match tolerance of 0.001 was used to matched 357 AIS patients to 68 AdIS patients. Operation duration, intraoperative blood loss (IBL), blood loss percentage, hemoglobin drift, blood salvaged, postoperative wound length, allogenic blood transfusion requirement, postoperative hospital stay, postoperative Cobb, correction rate and postoperative complications were documented and reported.

RESULTS

Following PSM, G1 and G2 each had 50 patients with comparable and balanced covariates. As anticipated, G2 patients were heavier, taller and had higher body mass index compared to G1 patients (P < 0.05). We could not find any significant differences in the perioperative outcome comparing this 2 groups. AIS and AdIS patients had similar operation duration (125.9 ± 27.2 min vs 127.3 ± 37.8 min), IBL (749.8 ± 315.7 ml vs 723.8 ± 342.1 ml) and length of hospital stay (3.3 ± 0.4 days vs 3.5 ± 0.8 days) (P > 0.05). Hemoglobin drift and amount of blood salvaged were comparable (P > 0.05). G2 had stiffer curves. There was a trend toward a lower correction rate in G2 in the immediate postoperative period, however it did not reach statistical significance (61.8 ± 11.2% vs. 66.3 ± 11.6%, P = 0.051). No patients required blood transfusion and none had any postoperative complications.

CONCLUSION

Adolescent and adult female scoliosis patients had comparable perioperative outcome following PSF surgery that was carried out using a dual attending surgeon strategy.

Complications of Autologous Stem Cell Transplantation in Multiple Myeloma: Results from the CALM Study

Background: The main goal of this post hoc analysis of the Collaboration to Collect Autologous Transplant Outcomes in Lymphoma and Myeloma (CALM) study was to evaluate the rate of short- and long-term infectious and non-infectious complications occurring after ASCT in patients with multiple myeloma (MM). Methods: The analysis included all patients with MM from the CALM study who underwent ≥1 ASCT. The primary endpoint of the analysis was to determine the rate of infectious and non-infectious complications after ASCT and to compare them in three time periods: 0−100 days, 101 days−1 year, and >1 year after the first transplant. Results: The analysis included a total of 3552 patients followed up for a median of 56.7 months (range 0.4−108.1). Complication rates decreased with the time from ASCT with 24.85 cases per 100 patient-years from day 0 to 100 days after the transplant, and <2.31 cases per 100 patient-years from the 101st day. At 100 days after ASC T, 45.7% of patients had complications, with infectious events being twice as frequent as non-infectious complications. Bacterial infections (6.5 cases per 100 patient-years, 95% CI: 6.1−7.0) and gastrointestinal complications (4.7 cases per 100 patient-years, 95% CI: 4.3−5.1) were the most common early events. The pattern of complications changed with time from ASCT. The presence of complications after ASCT was not associated with overall survival. Conclusions: Our data provide a solid basis for comparing ASCT-related complications to those caused by emerging treatments in multiple myeloma, such as CAR T-cell therapy and other immunotherapies.

Time to initiation of pre-emptive therapy for cytomegalovirus impacts overall survival in pediatric hematopoietic stem cell transplant recipients

BACKGROUND AIMS

Cytomegalovirus (CMV) reactivation is a significant complication following allogeneic hematopoietic stem cell transplant (HSCT) and affects upwards of 40% of pediatric HSCT patients. Pre-emptive therapy remains the only effective treatment strategy available for pediatric patients following CMV reactivation. Little is known about how the timing of induction treatment following CMV reactivation impacts outcomes in pediatric patients, especially following ex vivo T-cell-depleted (TCD) HSCT.

METHODS

The authors evaluated how the timing of induction treatment after CMV reactivation impacts overall survival (OS) and CMV disease in pediatric patients undergoing TCD HSCT at a single institution. The authors retrospectively analyzed patients treated on the pediatric service who received an initial ex vivo TCD HSCT at Memorial Sloan Kettering Cancer Center (MSKCC) from January 2010 to June 2018. CMV reactivation was defined as ≥1 CMV polymerase chain reaction >500 copies/mL in whole blood or >137 IU/mL in plasma within the first 180 days after allogeneic HSCT. To analyze the impact of the timing of induction treatment, the authors' primary study outcome was OS and secondary outcome was CMV disease.

RESULTS

A total of 169 patients who underwent an initial allogeneic TCD HSCT on the pediatric service at MSKCC from January 2010 to June 2018 were included in the analysis. Thirty-seven (22%) patients reactivated CMV during the first 180 days following HSCT. Of those patients who reactivated CMV, CMV donor/recipient (D/R) serostatus was as follows: D+/R+ n = 28 (76%) and D-/R+ n = 9 (24%). There was no CMV reactivation observed among recipients who were CMV-seronegative irrespective of donor serostatus. In those patients who reactivated CMV, the median time from HSCT to CMV reactivation was 24 days (interquartile range, 20-31). Eleven patients ultimately developed CMV disease in addition to CMV viremia, whereas the remaining patients had only CMV viremia. The cumulative incidence of CMV reactivation at 60 days was 45.2% (95% confidence interval [CI], 32.8-57.5) in the D+/R+ subgroup and 31% (95% CI, 14.2-47.9) in the D-/R+ subgroup. For those patients who reactivated CMV, 30 (81%) received induction treatment with ganciclovir or foscarnet. To analyze the impact of the timing of induction treatment on clinical outcomes, the authors restricted the analysis to those patients who reactivated CMV and received induction treatment (n = 30). The timing of induction treatment was significantly associated with OS, with optimal timing of initiation within a week of CMV reactivation (P = 0.02). There was no significant impact on the timing of induction treatment and risk of CMV disease (P = 0.30).

CONCLUSIONS

In ex vivo TCD HSCT in pediatric patients, early initiation of induction treatment after CMV reactivation is associated with improved OS.

Prophylaxis for invasive fungal infection in pediatric patients with allogeneic hematopoietic stem cell transplantation

Background

Antifungal prophylaxis is recommended for hematopoietic stem cell transplantation (HSCT) to decrease the incidence of invasive fungal infections (IFI). This study aimed to compare the two groups of antifungal prophylaxis in pediatric patients undergoing allogeneic HSCT.

Methods

This observational, analytic, retrospective cohort study compared the incidence of IFI with antifungal prophylaxis with voriconazole vs. other antifungals in the first 100 days after allogeneic HSCT in patients aged <18 years between 2012 and 2018. The statistical analysis included univariate and multivariate analyses and determination of the cumulative incidence of invasive fungal infection by the Kaplan‒Meier method using STATA 14 statistical software.

Results

A total of 139 allogeneic HSCT were performed. The principal diagnosis was acute leukemia (63%). The 75% had haploidentical donors, and 50% used an antifungal in the month before transplantation. Voriconazole (69%) was the most frequently administered antifungal prophylaxis. The cumulative incidence of IFI was 5% (7 cases). Of the patients with IFIs, four began prophylaxis with voriconazole, one with caspofungin, and one with fluconazole. Additionally, six were possible cases, one was proven (Candida parapsilosis), and 1/7 died.

Conclusion

There were no differences in the incidence of IFI between patients who received prophylaxis with voriconazole and other antifungal agents.

Oral mucositis in patients with acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation in relation to the conditioning used prior to transplantation

This study was designed to investigate the frequency and severity of oral mucositis in patients with acute myeloid leukemia after allogeneic hematopoietic cell transplantation, in relation to the type of conditioning used. Eighty patients diagnosed with acute myeloid leukemia were assigned to two groups based on the conditioning regimen used before transplantation. The intensity of oral inflammatory lesions induced by chemotherapy (oral mucositis) was evaluated according to a 5-point scale recommended by World Health Organization. Oral mucosa was investigated in all patients before the transplantation and during two subsequent stages of the post-transplantation procedure in relation to the conditioning regimen used. Mucositis in the oral cavity was observed in the majority of patients (66%) in the first week after transplantation, whereas the largest percentage of patients suffering oral lesions (74%) occurred in the second week after transplantation. A significantly higher percentage of patients with mucositis was observed in the group which underwent myeloablation therapy (74% of MAC and 50% of RIC patients in the first week; 83% of MAC and 53% of RIC patients in the second examination).The severity of mucositis after transplantation was higher in the MAC patients compared to the RIC patients. The highest mean value of the mucositis index was recorded in the second week in the MAC group (1.59). In AML sufferers receiving allo-HSCT, oral mucositis is a significant complication of the transplantation. This condition is more frequent and more severe in patients after treatment with myeloablation therapy.

Cytomegalovirus Infection and the Implications of Drug-Resistant Mutations in Pediatric Allogeneic Hematopoietic Stem Cell Transplant Recipients: A Retrospective Study from a Tertiary Hospital in China

INTRODUCTION

Drug-resistant cytomegalovirus (CMV) infection remains a challenge in the management of pediatric recipients of hematopoietic stem cell transplantation (HSCT). In this study, we retrospectively reviewed the clinical data on pediatric recipients of HSCT and identified known and unknown drug-resistant CMV variants.

METHODS

A total of 221 children underwent allogeneic HSCT between October 2017 and November 2019 at Shenzhen Children's Hospital; of these, 35 patients were suspected of having drug-resistant CMV infections and were tested for drug-resistant mutations in the UL97 and UL54 genes by Sanger sequencing.

RESULTS

Mutations in UL97 or UL54, or in both, were detected in 11 patients. Most of these mutations have not been previously reported. The UL97 mutation (A582V) was detected in only one patient who also harbored two UL54 mutations (T760X and R876W). One patient with both the G604S and T691A mutations in the UL54 gene died of CMV pneumonia. We investigated the risk factors associated with the development of drug-resistant CMV infection. Patients in whom both the donor and recipient had positive CMV serostatuses were less likely to have drug-resistant mutations (Fisher's exact test, p < 0.05).

CONCLUSION

Newly and previously detected CMV mutations in UL97 and UL54 may be associated with the development of drug-resistant CMV infection. The detection of these mutations may provide guidance for the management of post-transplant CMV infections.

Potential Risk Factors Associated With Graft Failure of Haploidentical Hematopoietic Stem Cell Transplantation in Children With Sickle Cell Disease

Nonmyeloablative (NMA) haploidentical hematopoietic stem cell transplantation for sickle cell disease has significantly increased donor availability for transplant and is increasingly used as curative treatment. The authors describe 3 pediatric patients who rejected grafts after an NMA regimen, previously reported to result in good engraftment rates in the mainly adult population. In this manuscript, potential factors contributing to rejection are described and discussed. The authors emphasize the need to further optimize the NMA regimens in pediatric patients and perform haploidentical transplants for sickle cell disease on clinical trials.

Factors Associated with Post-Transplant Active Epstein-Barr Virus Infection and Lymphoproliferative Disease in Hematopoietic Stem Cell Transplant Recipients: A Systematic Review and Meta-Analysis

This systematic review was undertaken to identify risk factors associated with post-transplant Epstein-Barr virus (EBV) active infection and post-transplant lymphoproliferative disease (PTLD) in pediatric and adult recipients of hematopoietic stem cell transplants (HSCT). A literature search was conducted in PubMed and EMBASE to identify studies published until 30 June 2020. Descriptive information was extracted for each individual study, and data were compiled for individual risk factors, including, when possible, relative risks with 95% confidence intervals and/or p-values. Meta-analyses were planned when possible. The methodological quality and potential for bias of included studies were also evaluated. Of the 3362 titles retrieved, 77 were included (62 for EBV infection and 22 for PTLD). The overall quality of the studies was strong. Several risk factors were explored in these studies, but few statistically significant associations were identified. The use of anti-thymocyte globulin (ATG) was identified as the most important risk factor positively associated with post-transplant active EBV infection and with PTLD. The pooled relative risks obtained using the random-effect model were 5.26 (95% CI: 2.92-9.45) and 4.17 (95% CI: 2.61-6.68) for the association between ATG and post-transplant EBV infection and PTLD, respectively. Other risk factors for EBV and PTLD were found in the included studies, such as graft-versus-host disease, type of conditioning regimen or type of donor, but results are conflicting. In conclusion, the results of this systematic review indicate that ATG increases the risk of EBV infection and PTLD, but the link with all other factors is either nonexistent or much less convincing.

Cytomegalovirus management after allogeneic hematopoietic stem cell transplantation: A mini-review

Because of the high incidence of cytomegalovirus (CMV) seropositivity in the population, CMV infection is a common and severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Taiwan. Here we propose a CMV management strategy for patients undergoing allo-HSCT from the Taiwanese perspective, which focuses on the epidemiology, diagnosis, monitoring, prophylaxis, and treatment of CMV infection after allo-HSCT. In terms of CMV monitoring, weekly CMV monitoring with the COBAS® AmpliPrep system is the standard approach because the pp65 CMV antigenemia assay has a lower sensitivity than CMV monitoring with the COBAS® AmpliPrep system. However, pp65 CMV antigenemia assay has a better correlation with clinical symptoms in immunocompromised patients. A 14-week prophylactic course of letermovir is recommended for allo-HSCT recipients in Taiwan, especially for recipients of hematopoietic stem cells from mismatched unrelated and haploidentical donors. Preemptive ganciclovir therapy should be initiated when the CMV viral load exceeds 1000 copies/mL, and should not be discontinued until CMV DNA is no longer detected in the blood. For allo-HSCT recipients who have CMV-related diseases, ganciclovir with or without CMV-specific intravenous immunoglobulin is the standard of care. The limited availability of foscarnet, an alternative for patients who are not responsive to or cannot tolerate ganciclovir, is a crucial issue in Taiwan. For pediatric allo-HSCT recipients, more data are needed to propose a CMV management recommendation.

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.

Casting a wider protective net: Anti-infective vaccine strategies for patients with hematologic malignancy and blood and marrow transplantation

Patients who have hematologic malignancies are at high risk for infections but vaccinations may be effective prophylaxis. The increased infection risk derives from immune defects secondary to malignancy, the classic example being CLL, and chemotherapies and immunotherapy used to treat the malignancies. Therapy of hematologic malignancies is being revolutionized by introduction of novel targeted agents and immunomodulatory medications, improving the survival of patients. At the same time those agents uniquely change the infection risk and response to immunizations. This review will summarize current vaccine recommendations for patients with hematologic malignancies including patients who undergo hematopoietic cell transplant.

Microbiology and Risk Factors for Hospital-Associated Bloodstream Infections Among Pediatric Hematopoietic Stem Cell Transplant Recipients

Background

Children undergoing hematopoietic stem cell transplantation (HSCT) are at high risk for hospital-associated bloodstream infections (HA-BSIs). This study aimed to describe the incidence, microbiology, and risk factors for HA-BSI in pediatric HSCT recipients.

Methods

We performed a single-center retrospective cohort study of children and adolescents (<18 years of age) who underwent HSCT over a 20-year period (1997–2016). We determined the incidence and case fatality rate of HA-BSI by causative organism. We used multivariable Poisson regression to identify risk factors for HA-BSI.

Results

Of 1294 patients, the majority (86%) received an allogeneic HSCT, most commonly with umbilical cord blood (63%). During the initial HSCT hospitalization, 334 HA-BSIs occurred among 261 (20%) patients. These were classified as gram-positive bacterial (46%), gram-negative bacterial (24%), fungal (12%), mycobacterial (<1%), or polymicrobial (19%). During the study period, there was a decline in the cumulative incidence of HA-BSI (P = .021) and, specifically, fungal HA-BSIs (P = .002). In multivariable analyses, older age (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], 1.01–1.06), umbilical cord blood donor source (vs bone marrow; IRR, 1.69; 95% CI, 1.19–2.40), and nonmyeloablative conditioning (vs myeloablative; IRR, 1.85; 95% CI, 1.21–2.82) were associated with a higher risk of HA-BSIs. The case fatality rate was higher for fungal HA-BSI than other HA-BSI categories (21% vs 6%; P = .002).

Conclusions

Over the past 2 decades, the incidence of HA-BSIs has declined among pediatric HSCT recipients at our institution. Older age, umbilical cord blood donor source, and nonmyeloablative conditioning regimens are independent risk factors for HA-BSI among children undergoing HSCT.