Wiskott-Aldrich Syndrome: A study on 577 patients defining the genotype as a predictive biomarker for disease severity.

WAS is a multifaceted monogenic disorder with a broad disease spectrum and variable disease severity and a variety of treatment options including allogeneic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT). No reliable biomarker exists to predict disease course and outcome for individual patients. A total of 577 patients with a WAS variant from 26 countries and a median follow-up of 8.9 years (0.3-71.1), totaling 6118 patient-years, were included in this international retrospective study. Overall survival (OS) of the cohort (censored at HSCT or GT) was 82% (95% CI 78-87) at 15 years and 70% (61-80) at 30 years of age. The type of variant was predictive of outcome: patients with a missense variant in exons 1 or 2 or with the intronic hotspot variant c.559+5G>A (class I variants) had a 15-year OS of 93% (89-98) and a 30-year OS of 91% (86-97), compared to 71% (62-81) and 48% (34-68) in patients with any other variant (class II; p<0.0001). The cumulative incidence rates of disease-related complications such as severe bleeding (p=0.007), life-threatening infection (p<0.0001), and autoimmunity (p=0.004) occurred significantly later in patients with a class I variant. The cumulative incidence of malignancy (p=0.6) was not different between classes I and II. This study represents the largest cohort of WAS patients studied so far. It confirms the spectrum of disease severity and quantifies the risk for specific disease-related complications. The class of variant is a biomarker to predict the outcome for WAS patients.

Incidence of bacterial and fungal infections in Polish pediatric patients with acute lymphoblastic leukemia during the pandemic.

The most common complications related to the treatment of childhood acute lymphoblastic leukemia (ALL) are infections. The aim of the study was to analyze the incidence and mortality rates among pediatric patients with ALL who were treated in 17 Polish pediatric hematology centers in 2020-2021 during the pandemic. Additionally, we compared these results with those of our previous study, which we conducted in the years 2012-2017. The retrospective analysis included 460 patients aged 1-18 years with newly diagnosed ALL. In our study, 361/460 (78.5%) children were reported to have microbiologically documented bacterial infections during chemotherapy. Ten patients (2.8%) died due to sepsis. Fungal infections were reported in 99 children (21.5%), of whom five (5.1%) died due to the infection. We especially observed an increase in bacterial infections during the pandemic period compared to the previous study. The directions of our actions should be to consider antibiotic prophylaxis, shorten the duration of hospitalization, and educate parents and medical staff about complications (mainly infections) during anticancer therapy. It is necessary to continue clinical studies evaluating infection prophylaxis to improve outcomes in childhood ALL patients.

Characteristics and Outcome of FLT3-ITD-Positive Pediatric Acute Myeloid Leukemia-Experience of Polish Pediatric Leukemia and Lymphoma Study Group from 2005 to 2022.

BACKGROUND: The FMS-like tyrosine kinase 3 (FLT3) gene mutated in 10-15% of pediatric acute myeloid leukemia (AML) is associated with an inferior outcome. The aim of the study was to analyze the outcome and characteristics of FLT3-ITD-positive pediatric AML. METHODS: We retrospectively analyzed the nationwide pediatric AML database from between 2005 and 2022. FLT3-ITD was found in 54/497 (10.7%) patients with available analysis. Three consecutive treatment protocols were used (AML-BFM 2004 Interim, AML-BFM 2012 Registry, AML-BFM 2019 recommendations). RESULTS: Probabilities of 5-year overall (OS), event-free (EFS) and relapse-free survival were significantly lower in the FLT3-ITD-positive patients compared to FLT3-ITD-negative (0.54 vs. 0.71, p = 0.041; 0.36 vs. 0.59, p = 0.0004; 0.47 vs. 0.70, p = 0.0029, accordingly). An improvement in the outcome was found in the analyzed period of time, with a trend of better survival in patients treated under the AML-BFM 2012 and AML-BFM 2019 protocols compared to the AML-BFM 2004 protocol (5-year EFS 0.52 vs. 0.27, p = 0.069). There was a trend of improved outcomes in patients treated with FLT3 inhibitors (n = 9, 2-year EFS 0.67 vs. 0.33, p = 0.053) and those who received stem cell transplantation (SCT) (n = 26; 5-year EFS 0.70 vs. 0.27, p = 0.059). The co-occurrence of the WT1 mutation had a dismal impact on the prognosis (5-year EFS 0.23 vs. 0.69, p = 0.002), while the NPM1 mutation improved survival (5-year OS 1.0 vs. 0.44, p = 0.036). CONCLUSIONS: It seems that SCT and FLT3 inhibitors have a beneficial impact on the prognosis. Additional genetic alterations, like the WT1 and NPM1 mutations, significantly influence the outcome.

Pediatric Acute Myeloid Leukemia Post Cytotoxic Therapy-Retrospective Analysis of the Patients Treated in Poland from 2005 to 2022.

Acute P./myeloid leukemia post cytotoxic therapy (AML-pCT) is rare complication of cancer treatment in childhood. The objective of the study was to identify clinical characteristics and provide an analysis of the outcomes in pediatric AML-pCT. We retrospectively analyzed the data of 40 children with AML-pCT, treated from 2005 to 2020 within the Polish Pediatric Leukemia and Lymphoma Study Group. The most common primary malignancies were acute lymphoblastic leukemia (32.5%) and brain tumors (20%). The median latency period was 2.9 years (range: 0.7-12.9). Probabilities of overall (OS), event-free (EFS), and relapse-free survival (RFS) in the whole cohort were 0.49 ± 0.08, 0.43 ± 0.08, and 0.64 ± 0.10, respectively. Significant improvements in outcomes were observed in patients treated from 2015-2022 (two induction cycles followed by stem cell transplantation-SCT in 69% of patients) compared to 2005-2014 (four induction cycles followed by SCT in 49% of patients). The probability of EFS increased from 0.30 ± 0.10 to 0.67 ± 0.12 (p = 0.07) and RFS increased from 0.46 ± 0.11 to 1.0 (p = 0.01). The poorest outcome (OS and EFS 0.25 ± 0.20) was in AML post brain tumor, mainly due to deaths from toxicities. To conclude, treatment results achieved in patients with AML-pCT treated from 2015-2022, with two induction cycles followed by immediate SCT, were better than those reported by other authors, and comparable to the results in de novo AML.

Viral Infection Profile in Children Treated for Acute Lymphoblastic Leukemia-Results of Nationwide Study.

Viral infections can be a serious complication of therapy in children with acute lymphoblastic leukemia (ALL). In this study, we focused on the incidence and the profile of viral infection in children with ALL treated in 17 pediatric oncology centers in Poland in the two-year periods of 2018-2019 and 2020-2021. We also compared the frequency of viral infections in 2018-2019 to that in 2020-2021. In 2020-2021, a total of 192 children with ALL had a viral infection during intensive chemotherapy. A total number of 312 episodes of viral infections were diagnosed. The most common infections detected in the samples were: COVID-19 (23%), rhinovirus (18%), and respiratory syncytial virus (14%). COVID-19 and BK virus infections were the reason for the death 1% of all patients. In 2018-2019, a total of 53 ALL patients who had a viral infection were reported and 72 viral events were observed, mainly adenovirus (48.6%), rotavirus (31.9%), and herpes zoster (8.3%). No deaths were reported during this period. The cumulative incidence of viral infections in 2018-2019 was 10.4%, while for 2020-2021, it was 36.7%. In conclusion, a high incidence of COVID-19 infection was observed among pediatric patients with ALL in Poland. The mortality rate in our material was low. The viral profile in ALL children undergoing chemotherapy can be useful for clinicians to improve prophylactic and therapeutic strategies.

Epidemiology of Fungal Colonization in Children Treated at the Department of Oncology and Hematology: Single-Center Experience.

Oncological patients are especially predisposed to fungal infections due to multiple risk factors and immunocompromising treatment. Epidemiological research regarding pediatric oncologic patients is still insufficient, and existing data are difficult to generalize on different populations. Therefore, we aimed to analyze fungal infections and fungal epidemiology in the Department of Oncology and Hematology of the University Children's Hospital in Krakow with help from the Clinical Microbiology Department. During the chosen period of 2005 and 2015-2020, 2342 tests were performed in our ward on 847 patients. Analyzed samples were divided into five source groups. The amount of patients with positive test results was 62.5%. The year with the highest detection level was 2005. The most frequent pathogen was Candida albicans, with a significant decrease in tendency. An increase in non-albicans species was observed. Candida parapsilosis was not frequently observed compared to similar studies. We noticed an increase in positive results from the urinary tract material. Our results confirmed that fungal infections are still an issue, and they may indicate the efficacy of prophylaxis. The majority of our results are consistent with the literature, yet we managed to emphasize data unique to our patients' population. Our findings are helpful in clinical work and for further studies in our center.

Fungal Infection Testing in Pediatric Intensive Care Units-A Single Center Experience.

Mycoses are diseases caused by fungi that involve different parts of the body and can generate dangerous treatment complications. This study aims to analyze fungal infection epidemiology in intensive care units (Pediatric and Cardiac Surgery Intensive Care Units-PCICU) and the Neonatal Intensive Care Unit (NICU) in one large pediatric center in the period 2015-2020 compared with 2005. The year 2005 was randomly selected as a historical time reference to notice possible changes. In 2005 and 2015-2020, 23,334 mycological tests were performed in intensive care units. A total of 4628 tests (19.8%) were performed in the intensive care units. Microbiological diagnostics involved mycological and serological testing. Of the 458 children hospitalized in the NICU, positive results in the mycological tests in the studied years were found in 21-27% of the children and out of 1056 PCICU patients, positive results were noticed in 18-29%. In both departments, the main detected pathogen was Candida albicans which is comparable with data published in other centers. Our experience indicates that blood cultures as well as the detection of antifungal antibodies do not add important information to mycological diagnostics. For the years of observation, only a few positive results were detected, even in patients with invasive fungal diseases. To our knowledge, this is one of a few similar studies over recent years and it provides contemporary reports of mycoses in pediatric ICU patients.

Monitoring of treatment with L-asparaginase in children with acute lymphoblastic leukaemia, with a focus on silent inactivation and its influence on the treatment outcome.

Introduction: The aim of the study was to analyse the frequency of silent inactivation and allergic reaction to asparaginase (ASP) and its impact on treatment results in patients with lymphoblastic leukaemia. Material and methods: Seventy patients with acute lymphoblastic leukaemia treated with ASP were enrolled in the study. Asparaginase activity was monitored. The patients were switched to another ASP formulation after allergy or inactivation. The treatment results were analysed. Results: Silent inactivation of native E. coli ASP was diagnosed in 5 patients (7%) and allergy in 34 patients (49%), and these patients were switched to pegylated ASP (PEG-ASP). Silent inactivation of PEG-ASP occurred in 8 patients (23%) and allergy in 6 patients (17%). Eight children continued therapy with Erwinase, and 4 did not switch to Erwinase after inactivation of PEG-ASP. Allergy to Erwinase occurred in 2 patients (22%); there was no inactivation. No significant differences in outcome were found between the groups of patients with and without allergy or silent inactivation of ASP. Due to regular monitoring and switching to other ASP preparations after allergy or silent inactivation, therapeutic activity was ensured in almost all patients. Conclusions: Monitoring of ASP activity is crucial to recognize silent inactivation and to guarantee treatment effectiveness by switching to other ASP preparations.

Concentrations of Insulin-like Growth Factors and Insulin-like Growth Factor-Binding Proteins and Respective Gene Expressions in Children before and after Hematopoietic Stem Cell Transplantation.

Insulin-like growth factors (IGF-1 and IGF-2) and insulin-like growth factor-binding proteins (IGFBP-1 to -7) are involved in the regulation of cell proliferation and differentiation and may be associated with various metabolic parameters. The aim of our study was to compare levels of IGFs and IGFBPs and the expressions of their genes in children before and after hematopoietic stem cell transplantation (HSCT) to assess their potential as markers of late metabolic complications of HSCT. We also conducted additional comparisons with healthy controls and of correlations of IGF and IGFBP levels with anthropometric and biochemical parameters. We analyzed 19 children treated with HSCT and 21 healthy controls. We found no significant differences in the levels of IGFs and IGFBPs and expressions of their genes before and after HSCT, while IGF and IGFBP levels were significantly lower in children treated with HSCT compared with controls. We conclude that our results did not reveal significant differences between the levels of IGFs and IGFBPs before and after HSCT, which would make them obvious candidates for markers of late complications of the procedure in children. However, due to the very low number of patients this conclusion must be taken with caution and may be altered by further research.

FTO and PLAG1 Genes Expression and FTO Methylation Predict Changes in Circulating Levels of Adipokines and Gastrointestinal Peptides in Children.

Adipokines and gastrointestinal tract hormones are important metabolic parameters, and both epigenetic factors and differential gene expression patterns may be associated with the alterations in their concentrations in children. The function of the FTO gene (FTO alpha-ketoglutarate dependent dioxygenase) in the regulation of the global metabolic rate is well described, whereas the influence of protooncogene PLAG1 (PLAG1 zinc finger) is still not fully understood. A cross-sectional study on a group of 26 children with various BMI values (15.3-41.7; median 28) was carried out. The aim was to evaluate the dependencies between the level of methylation and expression of aforementioned genes with the concentration of selected gastrointestinal tract hormones and adipokines in children. Expression and methylation were measured in peripheral blood mononuclear DNA by a microarray technique and a restriction enzyme method, respectively. All peptide concentrations were determined using the enzyme immunoassay method. The expression level of both FTO and PLAG1 genes was statistically significantly related to the concentration of adipokines: negatively for apelin and leptin receptor, and positively for leptin. Furthermore, both FTO methylation and expression negatively correlated with the concentration of resistin and visfatin. Cholecystokinin was negatively correlated, whereas fibroblast growth factor 21 positively correlated with methylation and expression of the FTO gene, while FTO and PLAG1 expression was negatively associated with the level of cholecystokinin and glucagon-like peptide-1. The PLAG1 gene expression predicts an increase in leptin and decrease in ghrelin levels. Our results indicate that the FTO gene correlates with the concentration of hormones produced by the adipose tissue and gastrointestinal tract, and PLAG1 gene may be involved in adiposity pathogenesis. However, the exact molecular mechanisms still need to be clarified.

Advances in the First Line Treatment of Pediatric Acute Myeloid Leukemia in the Polish Pediatric Leukemia and Lymphoma Study Group from 1983 to 2019.

BACKGROUND: From 1983, standardized therapeutic protocols for pediatric acute myeloid leukemia (AML) based on the BFM group experience were introduced in Poland. We retrospectively analyzed the results of pediatric AML treatment in Poland from 1983 to 2019 (excluding promyelocytic, therapy-related, biphenotypic, and Down syndrome AML). METHODS: The study included 899 children suffering from AML treated with the following: AML-PPPLBC 83 (1983-1993, n = 187), AML-PPGLBC 94 (1994-1997, n = 74), AML-PPGLBC 98 (1998-2004, n = 151), AML-BFM 2004 Interim (2004-2015, n = 356), and AML-BFM 2012 (2015-2019, n = 131). RESULTS: The probability of three-year overall survival was 0.34 ± 0.03, 0.37 ± 0.05, 0.54 ± 0.04, 0.67 ± 0.03, and 0.75 ± 0.05; event-free survival was 0.31 ± 0.03, 0.34 ± 0.05, 0.44 ± 0.04, 0.53 ± 0.03, and 0.67 ± 0.05; and relapse-free survival was 0.52 ± 0.03, 0.65 ± 0.05, 0.58 ± 0.04, 0.66 ± 0.03, and 0.78 ± 0.05, respectively, in the subsequent periods. A systematic reduction of early deaths and deaths in remission was achieved, while the percentage of relapses decreased only in the last therapeutic period. Surprisingly good results were obtained in the group of patients treated with AML-BFM 2012 with unfavorable genetic abnormalities like KMT2A-MLLT10/t(10;11)(p12;q23) and DEK-NUP214/t(6;9)(p23;q24), while unsatisfactory outcomes were found in the patients with FLT3-ITD. CONCLUSIONS: The use of standardized, systematically modified therapeutic protocols, with the successive consideration of genetic prognostic factors, and advances in supportive care led to a significant improvement in AML treatment outcomes over the last 40 years.

The Insight into Insulin-Like Growth Factors and Insulin-Like Growth-Factor-Binding Proteins and Metabolic Profile in Pediatric Obesity.

Insulin-like growth factors (IGFs) and insulin-like growth-factor-binding proteins (IGFBPs) regulate cell proliferation and differentiation and may be of importance in obesity development. The aim of the study was to analyze the expression of chosen IGF-axis genes and the concentration of their protein products in 28 obese children (OB) and 34 healthy control (HC), and their correlation with essential parameters associated with childhood obesity. The gene expression of IGFBP7 was higher, and the expression of IGF2 and IGFBP1 genes was lower in the OB. The expression of IGFBP6 tended to be lower in OB. IGFBP4 concentration was significantly higher, and IGFBP3 tended to be higher in the OB compared to the HC, while IGFBP1, IGFBP2, and IGFBP6 were significantly lower, and IGFBP7 tended to be lower in OB. We found numerous correlations between IGFs and IGFBP concentration and obesity metabolic parameters. IGFBP6 correlated positively with apelin, cholecystokinin, glucagone-like peptide-1, and leptin receptor. These peptides were also significantly lower in obese children in our study. The biological role of decreased levels of IGFBP6 in obese children needs further investigation.

The Expression of Genes Related to Lipid Metabolism and Metabolic Disorders in Children before and after Hematopoietic Stem Cell Transplantation-A Prospective Observational Study.

Metabolic disorders in children after hematopoietic stem cell transplantation (HSCT) are poorly characterized. However, it is known that dyslipidemia and insulin resistance are particularly common in these patients. We conducted a prospective study of 27 patients treated with HSCT to assess the possibility of predicting these abnormalities. We measured gene expressions using a microarray technique to identify differences in expression of genes associated with lipid metabolism before and after HSCT. In patients treated with HSCT, total cholesterol levels were significantly higher after the procedure compared with the values before HSCT. Microarray analysis revealed statistically significant differences in expressions of three genes, DPP4, PLAG1, and SCD, after applying the Benjamini-Hochberg procedure (pBH < 0.05). In multiple logistic regression, the increase of DPP4 gene expression before HCST (as well as its change between pre- and post-HSCT status) was associated with dyslipidemia. In children treated with HSCT, the burden of lipid disorders in short-term follow-up seems to be lower than before the procedure. The expression pattern of DPP4 is linked with dyslipidemia after the transplantation.

Methylation and Expression of FTO and PLAG1 Genes in Childhood Obesity: Insight into Anthropometric Parameters and Glucose-Lipid Metabolism.

The occurrence of childhood obesity is influenced by both genetic and epigenetic factors. FTO (FTO alpha-ketoglutarate dependent dioxygenase) is a gene of well-established connection with adiposity, while a protooncogene PLAG1 (PLAG1 zinc finger) has been only recently linked to this condition. We performed a cross-sectional study on a cohort of 16 obese (aged 6.6-17.7) and 10 healthy (aged 11.4-16.9) children. The aim was to evaluate the relationship between methylation and expression of the aforementioned genes and the presence of obesity as well as alterations in anthropometric measurements (including waist circumference (WC), body fat (BF_kg) and body fat percent (BF_%)), metabolic parameters (lipid profile, blood glucose and insulin levels, presence of insulin resistance) and blood pressure. Expression and methylation were measured in peripheral blood mononuclear cells using a microarray technique and a method based on restriction enzymes, respectively. Multiple regression models were constructed to adjust for the possible influence of age and sex on the investigated associations. We showed significantly increased expression of the FTO gene in obese children and in patients with documented insulin resistance. Higher FTO expression was also associated with an increase in WC, BF_kg, and BF_% as well as higher fasting concentration of free fatty acids (FFA). FTO methylation correlated positively with WC and BF_kg. Increase in PLAG1 expression was associated with higher BF%. Our results indicate that the FTO gene is likely to play an important role in the development of childhood adiposity together with coexisting impairment of glucose-lipid metabolism.

Hematopoietic stem cell transplantation for CD40 ligand deficiency: Results from an EBMT/ESID-IEWP-SCETIDE-PIDTC study.

BACKGROUND: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium species infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT). OBJECTIVE: We performed an international collaborative study to improve patients' management, aiming to individualize risk factors and determine optimal HSCT characteristics. METHODS: We retrospectively collected data on 130 patients who underwent HSCT for CD40L deficiency between 1993-2015. We analyzed outcome and variables' relevance with respect to survival and cure. RESULTS: Overall survival (OS), event-free survival (EFS), and disease-free survival (DFS) were 78.2%, 58.1%, and 72.3% 5 years after HSCT. Results were better in transplantations performed in 2000 or later and in children less than 10 years old at the time of HSCT. Pre-existing organ damage negatively influenced outcome. Sclerosing cholangitis was the most important risk factor. After 2000, superior OS was achieved with matched donors. Use of myeloablative regimens and HSCT at 2 years or less from diagnosis associated with higher OS and DFS. EFS was best with matched sibling donors, myeloablative conditioning (MAC), and bone marrow-derived stem cells. Most rejections occurred after reduced-intensity or nonmyeloablative conditioning, which associated with poor donor cell engraftment. Mortality occurred mainly early after HSCT, predominantly from infections. Among survivors who ceased immunoglobulin replacement, T-lymphocyte chimerism was 50% or greater donor in 85.2%. CONCLUSION: HSCT is curative in patients with CD40L deficiency, with improved outcome if performed before organ damage development. MAC is associated with better OS, EFS, and DFS. Prospective studies are required to compare the risks of HSCT with those of lifelong supportive therapy.

Ultrasound imaging as the basis of a clinical diagnosis of systemic bartonellosis in a patient after bone marrow transplantation. A case report.

Infections in immunocompromised patients after hematopoietic stem cell transplantation can have a severe and atypical course. Some opportunistic pathogens are difficult to detect in microbiological tests, and that is why treatment success depends on an accurate clinical diagnosis. This article presents a case of a 7-year-old girl with severe aplastic anemia treated with bone marrow transplantation with post-transplantation period complicated by persistent, hectic fever, with peak episodes of 39-40°C, lasting several weeks. Repeated microbiological tests failed to reveal the etiological agent, and empirical anti-infective treatment was ineffective. In the fourth week of fever, imaging showed multiple foci resembling abscesses in the patient's internal organs and, subsequently, in soft tissues. The characteristics of these changes and data concerning environmental exposure led to the clinical diagnosis of cat scratch disease (bartonellosis) with multi-organ involvement and enabled the targeted treatment to be implemented. Fever subsided and organ lesions regressed. In this case, repeated ultrasound imaging was the basic diagnostic tool that helped arrive at a correct diagnosis and implement effective treatment of this life-threatening complication after hematopoietic stem cell transplantation.

Visfatin concentrations in children with leukemia before and after stem cell transplantation.

Visfatin (VF) is an adipocytokine that performs many functions, including enhancing cell proliferation and biosynthesis of nicotinamide mononucleotides and dinucleotides. It also seems to be involved in the development of glucose metabolism disturbances. The goal of the study was the determination of VF concentrations in children with leukemia who are treated with stem cell transplantation. VF concentrations were measured in plasma before and after oral glucose tolerance test (OGTT; 60 and 120 minutes) in 22 children with leukemia treated with hematopoietic stem cell transplantation (HSCT) and healthy control subjects (n = 24). The HSCT group was studied twice: before HSCT (22 children) and approximately 6 months after HSCT (12 of 22 children). After fasting, concentrations of glucose, insulin, triglycerides, total cholesterol, high-density lipoprotein, and high-sensitivity C-reactive protein (hsCRP) were determined. Significantly lower (p < 0.05) median values of VF concentrations at all time points in the OGTT were found in pre- HSCT children compared with control subjects. The median VF concentration was significantly higher after HSCT compared with before HSCT. The decrease in VF in leukemic children in complete remission may be caused by myelosuppression and immunosuppression after prolong chemotherapy and is beneficial because of the decrease in its antiapoptotic activity. VF can serve as an additional biochemical marker for remission in patients with leukemia. Normalization of plasma VF concentration after HSCT might be caused by a process of immune reconstitution and prolonged inflammation (e.g., infections, graft-versus-host disease), injury to organs (e.g., lungs, gut, liver), and endocrinology deficiencies.

Status of immunity for vaccine--preventable diseases in children after hematopoietic stem cells transplantation.

INTRODUCTION: patients treated with hematopoietic stem cell transplantation (HSCT) lose immune memory accumulated through a lifetime. They are at increased risk of developing infections with microorganisms such as Haemophilus influenza, Streptococcus pneumoniae and others for which vaccines are available. Therefore, all patients after HSCT should be routinely revaccinated. Systemic reimmunization after HSCT is a relatively neglected area especially in countries which have not national recommendations and there is lack of systemic regulations in health care system. OBJECTIVE: the rate of immunization before transplantation and the persistence of vaccine-specific antibodies after HSCT was assessed. STUDY DESIGN: a group of38 children after stem cell transplantation (19 autologous, 19 allogeneic) was studied. RESULTS: only a few patients completed standard vaccination protocol before HSCT. At the median time of 29 (range: 6-67) months after autologous and 13 (range: 8-33) months after allogeneic HSCT, when the revaccination was commenced, the majority of children had concentration of antibody lower than the minimum protective thresholds. That was 82% for tetanus, 71% for Hib and varicella, 46% for HBV and 38% for diphtheria. CONCLUSIONS: all HSCT recipients should be routinely revaccinated to stimulate the immunity to the vaccine-preventable diseases.

[Mobilization and collection of hematopoietic stem cells in children with different neoplastic diseases for autotransplantation to support high dose chemotherapy (single centre experience)]. / Mobilizacja i separacja komórek krwiotwórczych u dzieci ze schorzeniami onko-hematologicznymi w celu autotransplantacji po wysokodawkowanej chemioterapii (doswiadczenia wlasne).

Currently, granulocyte colony stimulating factor (G-CSF) alone or in combination with myelosuppresive chemotherapy remain the standards of CD34+ cells mobilization allows the safe and successful collection of adequate peripheral blood stem cells (PBSC) for autologous transplantation. However, in up to 30% of patients mobilization of PBSC is ineffective. This report presents our experience in mobilization and collection of peripheral blood stem cells in 82 children with different proliferative disease. In mobilization G-CSF was administered alone in steady state (56 patients, pts) or in combination with myelosuppresive chemotherapy (26 pts). The CD34+ cell count at least 10 cells/ml was required to start apheresis procedure, which was repeated, if needed, during following 1-4 days until collection of at least 2 (optimally 3) x106 CD34+ cells/kg b.w. of recipient was obtained. Three pts in each group (3/ 56 and 3/26) failed the first course of mobilization. The median number of CD34+ cells mobilized was 4.8 (0.5-15) x106/kg b.w. The minimal and optimal number of CD34+ cells for transplantation was achieved in 85% and 61% of patients in the G-CSF + chemotherapy group and in 84% and 54% in the G-CSF group, respectively. The efficacy of presented mobilization arms in our group was similar. However, the incidence of infection and total hospitalization time during mobilization were higher in chemotherapy + G-CSF group.

Allogeneic haematopoietic stem cell transplantation as therapy for chronic granulomatous disease--single centre experience.

Chronic granulomatous disease (CGD) is phagocytic cell metabolic disorder resulting in recurrent infections and granuloma formation. This paper reports the favourable outcome of allogeneic transplantation in six high-risk CGD patients. The following donors were used: HLA-matched, related (two) and unrelated (three), and HLA-mismatched, unrelated (one). One patient was transplanted twice using the same sibling donor because of graft rejection at 6 months after reduced-intensity conditioning transplant (fludarabine and melphalan). Myeloablative conditioning regimen consisted of busulphan and cyclophosphamide. Stem cell source was unmanipulated bone marrow containing: 5.2 (2.6-6.5) × 10(8) nucleated cells, 3.8 (2.0-8.0) × 10(6) CD34+ cells and 45 (27-64) × 10(6) CD3+ cells per kilogramme. Graft-versus-host disease prophylaxis consisted of cyclosporine A and, for unrelated donors, short course of methotrexate and anti-T-lymphocyte globulin. Mean neutrophile and platelet engraftments were observed at day 22 (20-23) and day 20 (16-29), respectively. Pre-existing infections and inflammatory granulomas resolved. With the follow-up of 4-35 months (mean, 20 months), all patients are alive and well with full donor chimerism and normalized superoxide production.