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 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.

Usefulness of Post-Transplant Hematopoietic Chimera Monitoring by Use of the Quantitative Fluorescence Polymerase Chain Reaction Method.

BACKGROUND: In the light of an increasing number of hematopoietic stem cell transplantations and more frequent use of reduced-intensity conditioning as preparative regimens for hematopoietic stem cell transplantation, post-transplant cell chimera monitoring is considered a necessity. METHODS: The quantitative fluorescence polymerase chain reaction method, along with the commercial AmpFSTR SGMPlus kit, was applied in research on hematopoietic chimeras. RESULTS: The total of 102 patients who had undergone allogenic transplantations were investigated. Chimerism monitoring was commenced on the seventh day after transplantation and lasted up to 12 years in some cases, according to the instituted schedule. CONCLUSIONS: The kit has been shown to be fully sufficient for determining genetic profiles of recipients and donors and selecting informative markers. The method has been proven effective and satisfactory for assessing quantitative chimeras.

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.

Teenagers and young adults with cancer in Europe: from national programmes to a European integrated coordinated project.

Over 14 000 patients aged 15-24 are estimated to be diagnosed with cancer in the European Union (EU) each year. Teenagers and young adults (TYA) often fall down gaps between children's and adults cancer services. The specific challenges of providing optimal care to them are described, but we present a summary of recent progress. Progress to overcome these challenges is happening at different rates across Europe. We summarise the European national projects in this field but more recently we have seen the beginnings of European coordination. Within the EU 7th Funding Programme (FP7) European Network for Cancer Research in Children and Adolescents programme (ENCCA), a specific European Network for Teenagers and Young Adults with Cancer has held a series of scientific meetings, including professionals, patients and caregivers. This group has proposed unanswered research questions and agreed key features of a high-quality service that can improve outcomes for TYA with cancer, including the primacy of collaboration between adult and paediatric services to eliminate the gap in the management of TYA with cancer.

The immunophenotypes of blast cells in B-cell precursor acute lymphoblastic leukemia: how different are they from their normal counterparts?

BACKGROUND: Currently, there are three major maturational stages of CD19 antigen expressing B-cell precursors (hematogones). In B-cell precursor acute lymphoblastic leukemia (BCP-ALL), the malignant counterpart of hematogones, the leukemic blasts share common phenotypic features. The aim of the study was to enumerate the actual differences between the leukemic blasts in the CD10+ and CD10- subgroups of BCP-ALL and hematogones by assessing the expression of the antigens: TdT, CD34, CD45, CD10, CD38, CD20 and CD22. METHODS: To enable quantitative assessment of antigen expression on the different cell types, an objective scale of antigen expression was developed, the basis of which was direct fluorescence measurement using multicolor flow cytometry. RESULTS: All cases of CD10+ BCP-ALL clustered with type 1 hematogones. Among CD10-- BCP-ALL subgroup, 54.5%, 27.3% and 18.2% of cases clustered with type 1, 2 and 3 hematogones, respectively. In contrast to the CD10- blasts, the CD10+ blasts exhibited significantly higher levels of TdT, CD22, CD34 and CD20 expression. Conversely, CD10- blasts showed significantly higher expression of CD45 than CD10+ blasts, and a higher rate of CD45 antigen overexpression than CD10+ blasts (54.5% vs. 14.9% of cases, respectively). CONCLUSIONS: Multiparameter flow cytometry combined with the use of absolute antigen expression scale based on direct fluorescence measurement, has enabled a clear distinction between blasts in BCP-ALL cases and their normal counterparts. This novel and previously undescribed method has allowed the comparative analysis of antigen expression between leukemic blasts and different types of their normal counterparts.

Clinical experience with Optivate®, high-purity factor VIII (FVIII) product with von Willebrand factor (VWF) in young children with haemophilia A.

Optivate® is a high-purity FVIII/VWF product. Its safety, tolerability and efficacy in subjects ≥ 12 years have been demonstrated. This study was undertaken to assess Optivate® in children with haemophilia A. Twenty-five children, including one PUP (previously untreated patient), aged 1-6 years (mean 4.67 years) were treated with Optivate® for 26 weeks. Inhibitors were assessed every 3 months and viral status at the study start and end. Prophylaxis was used by five boys and on demand by twenty. The mean number of bleeds in the study was lower compared to the same period pre-study (12.0/child vs. 16.2/child), with fewer bleeds (P < 0.05) in the prophylactic subgroup (8.0/child) compared with the on-demand sub-group (13.4/child). Fourteen major bleeds were reported, all by the on-demand sub-group. Children on prophylaxis were administered a mean of 59.4 infusions; on-demand group 35.1 infusions. A total of 998 infusions were used with a mean dose of 29.1 IU kg⁻¹, and a mean of 38.6 exposure days (ED). Children < 4 years used higher doses, and reported fewer bleeds than older children. Children's Parents/Guardians rated Optivate® as helpful or very helpful in controlling 97.5% of bleeds by the prophylactic group, and in 98.5% of the bleeds in the on-demand group. Only 5 of 101 ADRs were treatment-related events (5%), all were mild and non-serious. There were no clinically significant changes in vital signs, viral transmissions or inhibitors. In young children Optivate® was well tolerated, safe and efficacious.

Treosulfan-based preparative regimens for allo-HSCT in childhood hematological malignancies: a retrospective study on behalf of the EBMT pediatric diseases working party.

This retrospective analysis evaluated 51 children (0.7-17 years; median eight) with high-risk or advanced hematological malignancies, including 18 (35%) patients undergoing second/third hematopoietic SCT (allo-HSCT), not eligible for standard myeloablative regimens and transplanted from matched sibling (MSD) (n=24) or matched unrelated (MUD) (n=27) donors. Preparative regimens were based on treosulfan (TREO) i.v., a structural analog of BU, given at total dose of 30 g/m(2) (n=21) or 36-42 g/m(2) (n=30) in combination with, fludarabine, cyclophosphamide, melphalan and/or VP-16 according to diagnosis, and risk factors. Deaths due to early regimen-related toxicity (RRT) did not occur. Nonrelapse mortality was 8% at 1 year and 16% after 4 years. Myeloid engraftment was achieved in 94%, complete donor chimerism in 90% of patients. A 4-year incidence of relapse was 24%, and was significantly lower after MUD-HSCT (8%) than after MSD-HSCT (39%), but similar in children undergoing first (28%) or second/third HSCT (17%). A 4-year disease-free survival was 61%, but it was significantly better in myeloid (73%), than in lymphoid malignancies (41%). Thus, children with high-risk and advanced hematological malignancies and high-risk of life-threatening RRT can be transplanted effectively and safely using TREO-based regimens. Particularly favorable results were achieved in myeloid malignancies and in children undergoing second HSCT.

The state of research into children with cancer across Europe: new policies for a new decade.

Overcoming childhood cancers is critically dependent on the state of research. Understanding how, with whom and what the research community is doing with childhood cancers is essential for ensuring the evidence-based policies at national and European level to support children, their families and researchers. As part of the European Union funded EUROCANCERCOMS project to study and integrate cancer communications across Europe, we have carried out new research into the state of research in childhood cancers. We are very grateful for all the support we have received from colleagues in the European paediatric oncology community, and in particular from Edel Fitzgerald and Samira Essiaf from the SIOP Europe office. This report and the evidence-based policies that arise from it come at a important junction for Europe and its Member States. They provide a timely reminder that research into childhood cancers is critical and needs sustainable long-term support.

Haematopoietic stem cell transplantation in children in eastern European countries 1985-2004: development, recent activity and role of the EBMT/ESH Outreach Programme.

The paediatric population of 19 eastern European countries amounts to approximately 80 million children. Between 1985 and 2004, the number of centres performing haematopoietic stem cell transplantation (HSCT) in children increased from 1 in 1985 to 24 in 2004 and the yearly number of paediatric HSCTs rose from 1 in 1985 to 291 in 2004. Altogether, 2342 transplants were reported to the EBMT Registry during this time (Poland 953, Czech Republic 501, Hungary 269, Russia 217, Croatia 129, Slovakia 71, Bulgaria 45, Serbia and Montenegro 36, Slovenia 35, Belarus 33, Estonia 26, Lithuania 19 and Romania 8). Out of the 2342 transplants, 1487 (63.5%) transplants were performed in paediatric centres, 453 (19.3%) in centres for adults and 402 (17.2%) in combined centres. The number of children who underwent autologous HSCT (auto-HSCT) was 1053 (45%), whereas 1289 (55%) underwent allogeneic HSCT (allo-HSCT). Peripheral blood (PB) was the source of HSC in 751 (71.3%) out of 1053 auto-transplants, BM in 246 (23.4%) and PB+BM in 52 (4.9%) (missing data in 4, that is, 0.4%). Among the 1289 allo-transplants, BM was the source of HSC in 827 (64.3%), PB in 416 (32.3%), CB in 23 (1.8%) and BM+PB in 14 (1.1%) (missing data in 9, that is, 0.7%). Among them, 728 (57.4%) obtained HSC from MSD, 322 (25.4%) from UD, 195 (15.4%) from MMFD, 14 (1.1%) from CB family donor and 9 (0.7%) from CB unrelated donor (missing data in 21, that is, 1.6%). The number of children who underwent allo-HSCT for malignant diseases was 945 (73.4%), including ALL 376 (29.2%), AML 234 (18.2%), CML 177 (13.8%), MDS 97 (7.5%), NHL 35 (2.7%) and other malignancy 31 (2.4%), while 339 (26.9%) for non-malignant disorders, including SAA 202 (15.7%), immunodeficiencies 61 (4.7%), inborn errors of metabolism 40 (3.1%), Fanconi anaemia 19 (1.5%) and others 17 (1.3%). Out of 1053 recipients of auto-HSCT, 168 (16%) were transplanted for neuroblastoma, 129 (12.2%) for NHL, 124 (11.7%) for AML, 114 (10.8%) for ALL, 109 (10.4%) for Hodgkin's disease, 62 (5.9%) for Ewing's sarcoma, 16 (1.5%) for CNS tumour, 15 (1.4%) for Wilms tumour and 316 (30%) for other tumours. In 2001, the EBMT in collaboration with the European School of Haematology (ESH) developed the Outreach Programme, that is a programme supporting emerging HSCT projects and transplant centres in countries with limited resources and/or experience.

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.

Dexrazoxane has no impact on sensitivity of childhood leukemic blasts to daunorubicin.

Dexrazoxane (DEX) prevents the formation of free radical, lipid peroxidation and cardiotoxicity caused by anthracyclines. Due to a concern about its possible interference with anthracyclin cytotoxicity, the in vitro effect of DEX on daunorubicin (DNR) cytotoxicity, cell cycle and induction of apoptosis by annexin-V was investigated. The sensitivity to DEX, DNR and their combination was tested by the MTT assay in human promyelocytic leukemia HL-60, the erythroid blast crisis CML K562 cell lines and in 45 children with ALL and AML. Cell cycle analysis and annexin-V expression were performed by flow cytometry. It has been observed that DEX itself weakly, but significantly caused cytotoxicity in both cell lines and in patient samples, especially in initial ALL samples. DEX sensitized K562 and HL60, but not patient samples, to cytotoxicity of DNR. The percentage of necrotic/apoptotic cells, as detected in cell cycle analysis and annexin V staining, was higher after exposure to DEX +/- DNR, when compared to respective samples not treated with DEX, in both cell lines but not in patient samples. Expression of annexin V induced by DEX in both cell lines was enlarged, regardless of the presence of DNR. This difference was not observed in patient samples, however, the number of cells expressing annexin V was higher after exposure to DEX +/- DNR in comparison to respective samples not treated with DEX. In conclusion, it seems that DEX possibly has no impact on the sensitivity of childhood leukemic blasts to DNR, however, has weak cytotoxic properties itself.

Translocation (Y;2) in childhood acute lymphoblastic leukemia.

A case of ALL in a 2 1/2-year-old boy with fatal outcome is presented. Cytogenetic analysis revealed a hypodiploid karyotype: 45,X-Y,-2,+der (2)t(Y;2),-12,i(17q),+mar. Some metaphases represented a sideline with 44 chromosomes and monosomy 8 was a consistent anomaly. These findings are rather uncommon in ALL. Hypodiploidy and the translocation, however, indicated poor prognosis in this case.

Cytogenetic studies in patients with multiple myeloma.

Fourteen patients diagnosed as having multiple myeloma were studied cytogenetically. In eight patients a sufficient number of metaphases was obtained and four of them showed abnormal karyotypes of bone marrow cells. Hypodiploidy was a consistent finding, as was the involvement of chromosome 9.

Distribution and relation of radiation induced chromosomal aberrations in human lymphocytes as seen in the first and second cell cycles.

Different types of chromosomal damage in the G(o) phase of human lymphocytes have been studied in the first (M1) and second cell lymphocytes (M2). Large populations of cells containing one dicentric chromosome and one acentric (DIC+) were observed in the second cycle. This indicates that these dicentric and acentric fragments have a normal distribution in M2 or, arose through loss of one acentric fragment (AC) from cells containing one dicentric and two acentric fragments (DIC++) in M1. Similarly, a large number of metaphases in M2 have unpaired differentiated ACs. Our data indicates that aberrant metaphases containing single AC or a DIC+ may undergo normal cell division and that these cells may not represent cells in the first cycle only, as was suggested by earlier workers. For radiation experiments to G(o), a desirable time to harvest human lymphocyte cultures appears to be 72 hours and screening of M1 and M2 cells by sister chromatid differentiation.

Use of radiation induced chromosomal damage in human lymphocytes as a biological dosimeter is questionable.

Using dicentric chromosomes and acentric fragments as indicators of radiation sensitivity, a study has been performed on human lymphocyte chromosomes by irradiating peripheral blood cells at G0. Donor-to-donor variation has been noticed regarding radiation sensitivity even when metaphase spreads were scored at the first cell cycle. Thus, it appears that, at the present state, use of chromosomal damage in peripheral blood cell cultures as an effective biological dosimeter for effects of radiation is questionable.