Adenovirus infection among pediatric patients with cancer and in pediatric recipients of hematopoietic stem cell: A multicenter nationwide study.

The aim was to evaluate the incidence, clinical course, and outcome of adenoviral infection (AdVI) in pediatric patients diagnosed and treated due to cancer and in pediatric recipients of hematopoietic stem cell. Over a 72-month period, all-in 5599 children with cancer: 2441 patients with hematological malignancy (HM) and 3158 with solid tumors (ST), and 971 patients after transplantation: 741 after allogeneic (allo-HSCT) and 230 after autologous (auto-HSCT) were enrolled into the study. Among cancer patients, 67 episodes of AdVI appeared in 63 (1.1%) children, including 45 (1.8%) with HM and 18 (0.6%; P < .001) with ST. Within transplanted patients, AdVIs were responsible for 88 episodes in 81 (8.3%) children (P < .001), including 78 (10.5%) patients after allo-HSCT and 3 (1.3%) after auto-HSCT. Time to develop AdVI was short, especially after allo-HSCT. The most common clinical manifestation in cancer patients was enteritis diagnosed in 63 (94.0%) cases, while among HSCT recipient asymptomatic adenoviremia was found in 36 (40.9%) cases and the most common clinical manifestation was urinary tract infection. Cancer patients with disseminated disease, as well as HSCT recipients with either asymptomatic viremia or disseminated disease, received antiviral treatment. The most commonly used first-line therapy was cidofovir. None of the cancer patients died due to AdVI, while within HSCT recipients three patients developed disseminated adenoviral disease and died despite antiviral treatment. In cancer patients, AdVIs are rare and associated with very good prognosis even without specific treatment. However, in allo-HSCT recipients, disseminated disease with fatal outcome is more likely to occur.

Multidrug-resistant bacterial infections in children undergoing haematopoietic stem cell transplantation over a 6-year period: analysis of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation.

AIMS: Multidrug-resistant (MDR) bacteria are an emerging cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT). The aim of the study was to analyse the incidence, clinical characteristics and survival from bacterial infections (BI) caused by MDR pathogens in paediatric HSCT recipients. METHODS AND RESULTS: Among 971 transplanted patients, BI were found in 416 children between the years 2012 and 2017. Overall, there were 883 bacterial episodes, which includes 85·8% after allo-HSCT and 14·2% after auto-HSCT. MDR strains were responsible for half of the total number of bacterial episodes. Over 50% of MDR pathogens were Enterobacteriaceae causing mainly gut infections or urinary tract infections. CONCLUSIONS: Regarding HSCT type, we did not find differences in the profile of MDR BI between allo- and auto-HSCT recipients. However, survival in MDR and non-MDR infections was comparable. SIGNIFICANCE AND IMPACT OF THE STUDY: The large sample size enables unique analysis and makes our data more applicable to other paediatric HSCT centres. In the absence of local epidemiological data, presented clinical characteristics of MDR-caused infections may be used to optimize the prophylactic strategies, early identification of infectious complications of MDR aetiology and thus promptly initiate adequate antibiotic therapy and further improve patients' outcome.

Incidence, course, and outcome of Clostridium difficile infection in children with hematological malignancies or undergoing hematopoietic stem cell transplantation.

Clostridium difficile infection (CDI) is one of the most common causes of nosocomial infectious diarrhea in children during anticancer therapy or undergoing hematopoietic stem cell transplantation (HSCT) in Europe. Immunosuppression in these patients is a risk factor for CDI. Malignant diseases, age, acute graft-versus-host disease (aGVHD), HLA mismatch, or use of total body irradiation may play an important role in CDI course. The aim of this study was to evaluate the incidence, course, and outcome of CDI in children treated for malignancy or undergoing HSCT. Between 2012 and 2015, a total number of 1846 patients were treated for malignancy in Polish pediatric oncological centers (PHO group) and 342 underwent transplantation (HSCT group). In PHO group, episodes of CDI occurred in 210 patients (14%). The incidence of CDI was higher in patients with hematological malignancies in comparison to that with solid tumors. Patients with acute myeloblastic leukemia had shorter time to episode of CDI than those with acute lymphoblastic leukemia. Patients over 5 years and treated for acute leukemia had more severe clinical course of disease in PHO group. In HSCT group, CDI occurred in 29 (8%) patients. The incidence of CDI was higher in patients transplanted for acute leukemia. The recurrence rate was 14.7% in PHO and 20.7% in HSCT patients. CDI incidence was highest in patients with hematological malignancies. Most of patients experienced mild CDI. Age < 5 years and diagnosis other than acute leukemia were the positive prognostic factors influencing clinical CDI course.

Incidence of Infectious Complications in Children With Acute Lymphoblastic Leukemia Treated With Hematopoietic Stem Cell Transplantation.

OBJECTIVE: We analyzed incidence and profile of infections in children with acute lymphoblastic leukemia (ALL) treated with hematopoietic stem cell transplantation (HSCT) in Polish pediatric HSCT departments, over a 2-year period. PATIENTS AND METHODS: Hospital records of 67 patients, who underwent allogeneic HSCT for ALL, were analyzed retrospectively for microbiologically documented infection: bacterial infection (BI), viral infection (VI), and fungal infection (FI). The majority of patients (40/67; 59.7%) underwent HSCT from matched unrelated donors (MUD). RESULTS: In total, 84 BI in 31 patients, 93 VI in 50 patients, and 27 FI in 22 patients were diagnosed. No differences were found in the frequency of occurrence of BI according to the type of transplant (P = .16); the occurrence of VI was statistically more frequent in MUD transplant recipients as compared with matched sibling donors (MSD) and mismatched related donors (MMFD; P = .001) and there was a trend in MUD patients for the higher occurrence of FI in comparison with MSD and MMFD transplants (P = .08). Regarding disease status, the occurrence of BI, VI, and FI was statistically more frequent in children who underwent transplantation in their first complete remission (CR1), rather than those who underwent transplantation in ≥CR2 (P < .05). In conclusion, infectious complications are an important cause of morbidity in children with ALL treated with allogeneic HSCT and the incidence of infections is high in this group of patients.

Bacterial infections in pediatric hematopoietic stem cell transplantation recipients: incidence, epidemiology, and spectrum of pathogens: report of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation.

BACKGROUND: Infectious complications are a significant cause of hematopoietic stem cell transplantation (HSCT) failure, especially allogeneic HSCT (allo-HSCT) because of delayed immune reconstitution and graft-versus-host disease (GVHD) occurrence. Identifying the factors responsible for bacterial infections (BI) in patients undergoing HSCT will provide much more effective empirical antimicrobial treatment in this group of patients. OBJECTIVE: The aim of this study was to evaluate the epidemiology and profile of BI in patients after HSCT in 5 centers of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation in 2012-2013. PATIENTS AND METHODS: In 308 HSCT recipients, we retrospectively analyzed 273 episodes of BI in 113 (36.7%) children aged 0.02-22 years (median age: 7 years), 92 after allo-HSCT and 22 after autologous HSCT (auto-HSCT). We assessed incidence of BI in different HSCT types by calculating the Index of Bacterial Infection (IBI) as a ratio of patients with at least 1 BI to all patients who underwent this type of HSCT in the analyzed period. We assessed the profile of BI with particular emphasis on multidrug-resistant organisms, and impact of underlying disease and of graft-versus-host disease on BI episodes. RESULTS: In the studied group, 273 episodes of BI were diagnosed, including 237 episodes after allo-HSCT and 36 after auto-HSCT. Among allo-HSCT recipients diagnosed with at least 1 BI, the IBI was 0.4 (matched sibling donor-HSCT 0.3; matched donor-HSCT 0.4; mismatched unrelated donor [MMUD]-HSCT 0.8; P = 0.027) and after auto-HSCT 0.3 per 1 transplanted patient. In patient after allo-HSCT because of myelo- or lymphoproliferative diseases and bone marrow failures, the major cause of infections was Enterobacteriaceae, while gram-positive bacteria predominated in the group with primary immunodeficiencies. In all patients after auto-HSCT, the dominant pathogen of BI were Enterobacteriaceae (P = 0.011). Time from each type of HSCT to infection caused by different pathogens did not differ significantly. CONCLUSIONS: The risk of BI does not depend on the underlying disease, but only on HSCT donor type and is the highest after MMUD-HSCT procedure. The profile of BI depends on the underlying disease and HSCT donor type, but does not depend on the occurrence of acute GVHD. Gram-negative bacteria predominated in patients with myelo- and lymphoproliferative diseases, while in patients with primary immunodeficiencies gram-positive strains were predominant.

Increased risk of infections and infection-related mortality in children undergoing haematopoietic stem cell transplantation compared to conventional anticancer therapy: a multicentre nationwide study.

This nationwide multicentre study analysed the epidemiology of bacterial, viral and fungal infections in paediatric haematopoietic stem cell transplantation (HSCT) and paediatric haematology and oncology (PHO) patients over a period of 24 consecutive months, including incidence, hazard risk and outcome of infections as well as occurrence of multidrug-resistant bacteria. During this period, 308 HSCTs were performed and 1768 children were newly diagnosed for malignancy. Compared to PHO, the risk in HSCT patients was significantly higher for all infections (hazard ratio (HR) 2.7), bacterial (HR 1.4), fungal (HR 3.5) and viral (HR 15.7) infections. The risk was higher in allo- than auto-HSCT for bacterial (HR 1.4), fungal (HR 3.2) and viral (HR 17.7) infections. The incidence of resistant bacteria was higher in HSCT than in PHO patients for both G-negative (72.5% vs. 59.2%) and G-positive (41.4% vs. 20.5%) strains. Cumulative incidence of bacterial, fungal and viral infections in HSCT patients was 33.9, 22.8 and 38.3%, respectively. Cumulative incidence of viral infections in allo-HSCT was 28.0% for cytomegalovirus, 18.5% for BK virus, 15.5% for Epstein-Barr virus, 9.5% for adenovirus, 2.6% for varicella zoster virus, 0.9% for influenza, 0.9% for human herpesvirus 6 and 0.3% for hepatitis B virus. Survival rates from infections were lower in HSCT than in PHO patients in bacterial (96.0 vs. 98.2%), fungal (75.5 vs. 94.6%) and most viral infections. In conclusion, the risk of any infections and the occurrence of resistant bacterial strains in allo-HSCT patients were higher than in auto-HSCT and PHO patients, while the outcome of infections was better in the PHO setting.

Adoptive therapy with donor lymphocyte infusion after allogenic hematopoietic SCT in pediatric patients.

The aim of this study was to analyse the experience of Polish Pediatric Group for Hematopoietic Stem Cell Transplantation in respect to donor lymphocyte infusion procedure. The study included 51 pediatric patients with malignant (45) and non-malignant (6) diseases treated with DLI in the period 1993-2012. The indications for DLI were as follows: (1) increasing recipient chimerism after non-ablative hematopoietic SCT (18 patients); (2) immunomodulation after a reduced intensity conditioning regimen (2 patients); (3) increase in minimal residual disease detection (3 patients); and (4) relapse (28 patients). DLI was carried out at a median of 6 (0.5-79) months after SCT. DLI was administered as either a single-dose (in 19 cases) or in escalating-dose regimens (in 32 cases). The median total dose of CD3-positive T cells was 28.0 (0.1-730.0) × 10(6)/kg body weight. The time for assessment of DLI efficacy ranged from 0 to 70 (median 3) months. At evaluation, 18 patients experienced CR, 3 achieved PR, 19 showed relapse and 11 rejected the graft. DLI was found to be effective in 39% of cases. Complications of the procedure occurred in 18 patients; of these, 2 died. To sum up DLI shows efficacy in a significant percentage of children. Mortality related to the therapy adverse effects is low. However, this method requires standardization.

Consolidation of first-line therapy with busulphan and melphalan, and autologous stem cell rescue in children with Ewing's sarcoma.

According to the published report on current practice of hematopoietic SCT in Europe, high-dose therapy (HDT) with autologous stem cell support is a standard of care in paediatric patients with high risk (HR) or relapsed Ewing's sarcoma (ES). Randomized trials, however, have not confirmed the value of this procedure yet. In this retrospective analysis we intended to evaluate the role of HDT as a consolidation therapy in first remission of ES. A total of 102 patients were included in the analysis and divided according to the following risk factors: metastatic disease at presentation, feasibility of surgery and histological response after induction. Forty-one patients were classified as standard risk (SR) patients, while the remaining 61 children, with at least one risk factor, were classified as HR patients. HR group patients were non-randomized and qualified according to the decision of the local clinician to give a conventional consolidation (CC) or to perform high-dose chemotherapy and radiotherapy in selected patients. Twenty-six children were given CC while 35 patients were treated with HDT. The HDT consisted of oral BU 4 mg/kg p.o. in divided doses daily for 4 days (total dose 16 mg/kg) followed by melphalan 140 mg/m(2) i.v. on day -2. Probability of relapse-free survival (RFS) in median observation time was significantly worse in HR patients who were given CC therapy as compared with children with HR features receiving high-dose chemotherapy (0.27 vs 0.66 (P = 0.008); OS 0.31 vs 0.71 (P = 0.007), respectively). Patients from the SR group had a probability of RFS of 0.72 and OS of 0.75, and the difference between SR and HR patients after HDT was NS (P = 0.37). Our observation confirms that the consolidation of the first-line treatment with BU and melphalan improves the outcome in ES patients with HR features.

Neurologic complications in children after hemaopoietic stem cell transplantation: a single-center experience.

UNLABELLED: Neurologic complications may occur in patients undergoing haematopoietic stem cell transplantation (HSCT). The aim of the study was to evaluate the frequency and type of neurologic complications in children after HSCT. We performed a retrospective analysis of the incidence and outcome of neurologic complications among 171 consecutive children transplanted in one center. RESULTS: Among 84 autologous and 87 allogeneic (47 matched sibling donors, 31 matched unrelated donors, 8 mismatched family donors, and 1 cord blood) transplants, 7 patients (4%) developed neurologic complications, all of whom had undergone allogeneic transplantation (7/87 = 8%). These patients had relapses of acute leukemia (n = 3; acute myeloblastic in two and acute lymphoblastic in one), chronic leukemia, (n = 1), myelodysplastic syndrome (n = 2), and adrenoleudystrophy X (n = 1). Neurologic complications occurred after a median follow-up of 1 month (range, 14 days to 19 months). Of seven patients, four died. Neurologic complications were the cause in two patients. CONCLUSIONS: Among the analyzed material the risk of neurologic complications was lower than in other studies and these events were observed only in children undergoing allogeneic transplantation.