Different Kinetics and Risk Factors for Isolated Extramedullary Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Acute Leukemia.

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most frequent cause of post-transplantation mortality. Isolated extramedullary (EM) relapse (iEMR) after HSCT is relatively rare and not well characterized, particularly in pediatric patients. We retrospectively analyzed 1527 consecutive pediatric patients with acute leukemia after allo-HSCT to study the incidence, risk factors, and outcome of iEMR compared with systemic relapse. The 5-year cumulative incidence of systemic relapse (either bone marrow [BM] only or BM combined with EMR) was 24.8%, and that of iEMR was 5.5%. The onset of relapse after allo-HSCT was significantly longer in EM sites than in BM sites (7.19 and 5.58 months, respectively; P = .013). Complete response (CR) 2+/active disease at transplantation (hazard ratio [HR], 3.1; P < .001) and prior EM disease (HR, 2.3; P = .007) were independent risk factors for iEMR. Chronic graft-versus-host disease reduced the risk of systemic relapse (HR, 0.5; P = .043) but did not protect against iEMR. The prognosis of patients who developed iEMR remained poor but was slightly better than that of patients who developed systemic relapse (3-year overall survival, 16.5% versus 15.3%; P = .089). Patients experiencing their first systemic relapse continued to have further systemic relapse, but only a minority progressed to iEMR, whereas those experiencing their iEMR at first relapse developed further systemic relapse and iEMR at approximately similar frequencies. A second iEMR was more common after a first iEMR than after a first systemic relapse (58.8% versus 13.0%; P = .001) and was associated with poor outcome. iEMR has a poor prognosis, particularly after a second relapse, and effective strategies are needed to improve outcomes.

Comparison of Total Body Irradiation-based Versus Chemotherapy-based Conditionings for Early Complications of Allogeneic Hematopoietic Stem Cell Transplantation in Children With ALL.

BACKGROUND: Total body irradiation (TBI) is the cornerstone of conditioning regimens in pediatric hematopoietic stem cell transplantation for acute lymphoblastic leukemia. As the late effects and survival comparison between TBI and chemotherapy were well analyzed before, in this study, we aim to focus on the first 100 days and early complications of transplantation. METHODS: This retrospective study involves 72 pediatric patients (0 to 18 y) underwent first hematopoietic stem cell transplantation for acute lymphoblastic leukemia between October 2015 and May 2019. Patients are divided into 2 groups regarding conditioning regimens. Conditionings includes either TBI 1200 cGy/6 fractions/3 days and etoposide phosphate or busulfan, fludarabine, and thiotepa. Busulfan was administered IV and according to body weight. RESULTS: The incidences of acute graft versus host disease grade 2 to 4, veno-occlusive disease, capillary leakage syndrome, thrombotic microangiopathy, blood stream infection, hemorrhagic cystitis and posterior reversible encephalopathy syndrome before day 100 were similar for both conditioning regimens; however, patients received TBI-based conditioning had significantly longer neutrophil engraftment time (17.5 vs. 13 d, P=0.001) and tended to have more engraftment syndrome (ES) (45.5% for TBI vs. 24.0% for chemotherapy, P=0.069). Multivariate analysis showed that TBI-based conditioning was associated with a longer neutrophil engraftment time (hazard ratio [HR]=1.20, P=0.006), more cytomegalovirus (CMV) reactivation (HR=3.65, P=0.038) and more ES (HR=3.18, P=0.078). CONCLUSIONS: Our findings support chemotherapy-based regimens with early neutrophil engraftment, less ES and CMV reactivation compared with TBI. Although there is no impact on survival rates, increased incidence of ES and CMV reactivation should be considered in TBI-based regimens.

Hematopoietic stem cell transplantation in CD40 ligand deficiency: A single-center experience.

Deficiency of the CD40L, expressed on the surface of T lymphocytes, is caused by mutations in the glycoprotein CD40L (CD154) gene. Resulting defective humoral and cellular responses cause a clinical presentation that includes recurrent sinopulmonary bacterial infections, opportunistic infections, sclerosing cholangitis, neutropenia, and autoimmune manifestations. HSCT represents the only curative treatment modality. However, the therapeutic decision to use HSCT proves challenging in many cases, mainly due to the lack of a phenotype-genotype correlation. We retrospectively reviewed patients with CD40L deficiency who were transplanted in Antalya and Göztepe MedicalPark Pediatric HSCT units from 2014 to 2019 and followed by Akdeniz University School of Medicine Department of Pediatric Immunology. The records of eight male cases, including one set of twins, were evaluated retrospectively. As two transplants each were performed on the twins, a total of ten transplants were evaluated. Conditioning regimens were predominantly based on myeloablative protocols, except for the twins, who received a non-myeloablative regimen for their first transplantation. Median neutrophil and platelet engraftment days were 13 (range 10-19) and 14 (range 10-42) days, respectively. In seven of ten transplants, a CMV reactivation was developed without morbidity. None of the patients developed GVHD, except for one mild case of acute GVHD. All patients survived, and the median follow-up was 852 days. Our data show that HSCT for patients with CD40 ligand deficiency is a potentially effective treatment for long-term disease control.

Role of a second transplantation for children with acute leukemia following posttransplantation relapse: a study by the Turkish Bone Marrow Transplantation Study Group.

We examined outcomes of 51 pediatric patients with relapsed acute leukemia (AL) who underwent a second allogeneic hematopoietic stem cell transplantation (alloHSCT). After a median follow-up of 941 days (range, 69-2842 days), leukemia-free survival (LFS) and overall survival (OS) at 3 years were 26.6% and 25.6%, respectively. The nonrelapse mortality rate (NMR) and cumulative incidence of relapse (CIR) were 36.4% and 42.4%, respectively. The Cox regression analysis demonstrated that the risk factors at second transplantation for predicting limited LFS were active disease (hazard ratio (HR) = 5.1), reduced intensity conditioning (RIC) (HR = 5.0), matched unrelated donor (MUD) (HR = 3.4) and performance score <80 (HR = 3.2). Pediatric patients with AL who relapsed after their first alloHSCT may survive with a second alloHSCT. Disease status, conditioning intensity, donor type, and performance score at the second transplantation are the relevant risk factors. A score based on these factors may predict the results of the second transplantation.

Heterozygous activating mutation in RAC2 causes infantile-onset combined immunodeficiency with susceptibility to viral infections.

Here we describe a 10-year-old girl with combined immunodeficiency presenting as recurring chest infections, lung disease and herpetic skin infections. The patient experienced two hematopoietic stem cell transplantations and despite full chimerism, she developed bone marrow aplasia due to adenovirus infection and died at post-transplant day 86. Immunologic investigation revealed low numbers of TRECs/KRECs, a severe reduction of memory B cells, absence of isohemagglutinins, and low IgG levels. Whole exome sequencing (WES) identified a novel heterozygous mutation in RAC2(c.275A > C, p.N92 T). Flow cytometric investigation of neutrophil migration demonstrated an absence of chemotaxis to fMLP. Cell lines transfected with RAC2 [N92 T] displayed characteristics of active GTP-bound RAC2 including enhanced NADPH oxidase-derived superoxide production both at rest and in response to PMA. Our findings broaden the clinical picture of RAC2 dysfunction, showing that some individuals can present with a combined immunodeficiency later in childhood rather than a congenital neutrophil disease.

Risks and outcomes of invasive fungal infections in pediatric allogeneic hematopoietic stem cell transplant recipients receiving fluconazole prophylaxis: a multicenter cohort study by the Turkish Pediatric Bone Marrow Transplantation Study Group.

Invasive fungal infections (IFIs) are a major cause of infection-related morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Data from pediatric settings are scarce. To determine the incidence, risk factors and outcomes of IFIs in a 180-day period post-transplantation, 408 pediatric patients who underwent allogeneic HSCT were retrospectively analyzed. The study included only proven and probable IFIs. The cumulative incidences of IFI were 2.7%, 5.0%, and 6.5% at 30, 100, and 180 days post-transplantation, respectively. According to the multivariate analysis, the factors associated with increased IFI risk in the 180-day period post-HSCT were previous HSCT history (hazard ratio [HR], 4.57; 95% confidence interval [CI] 1.42-14.71; P = .011), use of anti-thymocyte globulin (ATG) (HR, 2.94; 95% CI 1.27-6.80; P = .012), grade III-IV acute graft-versus-host-disease (GVHD) (HR, 2.91; 95% CI 1.24-6.80; P = .014) and late or no lymphocyte engraftment (HR, 2.71; 95% CI 1.30-5.62; P = .007). CMV reactivation was marginally associated with an increased risk of IFI development (HR, 1.91; 95% CI 0.97-3.74; P = .063). IFI-related mortality was 1.5%, and case fatality rate was 27.0%.The close monitoring of IFIs in pediatric patients with severe acute GVHD who receive ATG during conditioning is critical to reduce morbidity and mortality after allogeneic HSCT, particularly among those with prior HSCT and no or late lymphocyte engraftment.

Risk factors predicting the survival of pediatric patients with relapsed/refractory non-Hodgkin lymphoma who underwent hematopoietic stem cell transplantation: a retrospective study from the Turkish pediatric bone marrow transplantation registry.

We examined outcomes of 62 pediatric patients with relapsed or refractory non-Hodgkin lymphoma (rr-NHL) who underwent hematopoietic stem cell transplantation (HSCT). The overall survival (OS) and event-free survival (EFS) rates were 65% and 48%, respectively. Survival rates for patients with chemosensitive disease at the time of HSCT were significantly higher than those of patients with chemoresistant disease (69% vs. 37%, p = .019 for OS; 54% vs. 12%, p < .001 for EFS; respectively). A chemoresistant disease at transplantation was the only factor that predicted a limited OS (hazard ratio = 10.00) and EFS (hazard ratio = 16.39) rates. Intensive chemotherapy followed by HSCT could be an effective strategy for treating children with rr-NHL and may offer improved survival for a significant group of pediatric patients, particularly those with chemosensitive disease at transplantation.

Outcome of autologous hematopoietic stem cell transplantation in children and adolescents with relapsed or refractory Hodgkin's lymphoma.

This study evaluates the outcome of 66 pediatric patients with rrHL who underwent autoHSCT. Twenty-nine patients experienced early relapse, and 19 patients experienced late relapse. Of 18 newly diagnosed with HL, 13 were primary refractory disease and five had late responsive disease. At the time of transplantation, only 68% of the patients were chemosensitive. The majority of patients received BCNU + etoposide + ara-C + melphalan for conditioning (45/66), and peripheral blood (56/66) was used as a source of stem cells. After a median follow-up period of 39 months, 46 patients were alive. At five yr, the probabilities of OS, EFS, the relapse rate, and the non-relapse mortality rate were 63.1%, 54.3%, 36.4%, and 9.1%, respectively. The probability of EFS in chemosensitive and chemoresistant patients at five yr was 72.3% and 19%, respectively (p < 0.001). Multivariate analysis showed that chemoresistant disease at the time of transplantation was the only factor predicting limited both OS (hazard ratio = 4.073) and EFS (hazard ratio = 4.599). AutoHSCT plays an important role for the treatment of rrHL in children and adolescents, and survival rates are better for patients with chemosensitive disease at the time of transplantation.

Clinical heterogeneity of immunodysregulation, polyendocrinopathy, enteropathy, X-linked: pulmonary involvement as a non-classical disease manifestation.

PURPOSE: IPEX (Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked) is a rare X-linked recessive life-threatening disorder characterized by autoimmunity and early death. Pulmonary complication related with IPEX has not been elucidated exactly. Here, we report 4 IPEX patients, 3 of which died from severe pulmonary disease. METHODS: Clinical data and laboratory findings including autoantibodies, immunoglobulin levels as well as number of T, B and NK cells were evaluated. FOXP3 expression and T reg activity were analyzed. The FOXP3 gene was sequenced and RNA analysis was performed. RESULTS: Patient I (PI) presented with nephrotic syndrome at 3 years of age and then developed autoimmune hepatitis without eczema, enteropathy or high IgE and died at 9 years of age due to acute respiratory distress syndrome (ARDS). Two cousins of PI had the same hypomorphic splice site mutation leading to a deletion of 27 amino acids, but normal FOXP3 protein expression and normal suppressive capacity of T reg in a proliferation inhibition assay. However, they exhibited typical symptoms such as eczema, diabetes and enteropathy with eosinophilia at early age (PII, PIII) and were transplanted in infancy. One of them had severe respiratory distress right after birth (PIII). Patient IV from another family presented with chronic diarrhea without autoimmune manifestations and died due to ARDS. CONCLUSION: Lung disease related to IPEX syndrome has not been reported before and this entity could be a critical factor in disease outcome.

Quality of life assessment in hematopoietic stem cell transplantation performed on thalassemia major patients.

Although successful hematopoietic stem cell transplantation (HSCT) can offer a cure in thalassemia major, there are only a few and noncomprehensive studies of its effect on the quality of life (QoL), as it is expected to increase the QoL by ending transfusion-related issues. Our objective was to compare the health-related quality of life (HRQoL) of transplanted and nontransplanted thalassemia major patients in a developing country. We have studied the QoL effect of HSCT in consecutively invited 50 nontransplanted and 49 transplanted patients who had received transplants from HLA matched related donors at least two years ago. PedsQL questionnaire was used for the patients under 18 years of age and World Health Organization's WHOQoL-BREF questionnaire for above 18 years of age. Higher QoL was determined in HSCT performed group surveyed in 5-18 years' age group. Detailed analysis marked the profound difference in 8-12 year subgroup, particularly in physical activity questionnaires. QoL scores in HSCT performed adult group are higher than the transfusion-dependent group, especially in physical activity domain. Transplanted adult patients rated their overall health significantly better than patients on conventional therapy. The patients who still have chronic graft versus host disease rated worse compared to those without it. In conclusion, thalassemia major patients who have undergone HSCT at least two years before assessment are not inferior to the transfusion-dependent group with regard to the QoL and have a better QoL than transfusion-dependent patients in some areas. The QoL score is better for school children and adolescents; therefore, we suggest HSCT before primary school. GVHD reduces the QoL significantly and it is obvious that GVHD prevention should be one of the primary goals of post-HSCT follow-up.

A rare cause of a relatively common neonatal emergency.

Malignant infantile osteopetrosis (MIOP) is a rare cause in the list of etiological factors of neonatal hypocalcemia in several textbooks. The most severe complication of MIOP is bone marrow suppression. The abnormal expansion of bone interferes with medullary haematopoiesis. Most children with this disease die within the first decade of life of secondary consequence of bone marrow failure. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for MIOP, an otherwise fatal disease. We present a neonate with MIOP that was further complicated with vitamin D deficiency.

The value of donor lymphocyte infusions in thalassemia patients at imminent risk of graft rejection following stem cell transplantation.

BACKGROUND: The aim was to evaluate the feasibility of donor lymphocyte infusion (DLI) in transplanted patients with thalassemia who were at imminent risk of graft rejection (GR). PROCEDURE: We retrospectively evaluated outcomes in a cohort of 19 patients with thalassemia who received DLI following 21 transplantations. Patients were divided into three groups depending on indication and time of DLI: group I, mixed chimerism-level-3 (MC-level-3) within 2 months and subsequently receiving DLI; group II, MC-level-3 within 2 months and receiving deferred DLI beyond post-transplant 2.5 months; group III, receiving DLI because of a gradual decrease in both donor cells and hemoglobin levels without MC-level-3 within 2 months. RESULTS: Three patients evolved to compete chimerism (16%), 9 patients had MC with transfusion independency (47%) and 7 had GR (37%). Three of 7 patients in group I, 1 of 4 patients in group II and 8 of 10 patients in group III preserved the graft. Although significant increases in the percentage of donor cells were not detected in group III, hemoglobin levels improved (median, 6.8-8.8 g/dl, P = 0.002). CONCLUSION: The risk of GR is high in patients with thalassemia who have MC-level-3 within 2 months after transplantation. DLI is a feasible method for converting unstable MC towards stable MC or full donor chimerism, but its efficacy is partially related to the percentage of residual host cells at the time of infusion. Serial chimerism studies can identify unstable MC earlier and may guide the proper timing of intervention.

Childhood acute lymphoblastic leukemia in Turkey: factors influencing treatment and outcome: a single center experience.

There is limited data about the long-term treatment outcome and prognosis of childhood acute lymphoblastic leukemia (ALL) in developing countries. Our study was designed to assess survival data and identify risk factors. Data of 142 children with ALL who were treated with a modified BFM 95 protocol between 1997 and 2007 were evaluated. The median age was 4.3 years. Complete remission (CR) rate after induction phase was 93.5%; with 2.1% induction-related mortality and 0.7% having resistance disease. Of complete responders, 67.1% are in continuous CR with a median follow-up of 63 months (range: 24 to 153 mo). Treatment-related mortality was 17.7% and the total rate of treatment abandonment was 3.5%. The probability of event-free survival was 67.3% (95% confidence interval 59.3-75.3) at 4 years and 63.2% (95% confidence interval 54.4-72.0) at 8 years. This report examines children with ALL treated with a modified ALL-BFM 95 protocol in a tertiary care center in Turkey with adequate follow up and demonstrates the need for improvements especially for patients with unfavorable risk group and strategies to reduce deaths from infection in CR to keep pace with cure rates in developed countries.

Prognostic factors in pediatric cancer patients admitted to the pediatric intensive care unit.

Higher mortality and morbidity are well established in children with malignancies in whom intensive care admissions are required. A retrospective cohort study was conducted to assess the risk factors for children with cancer in the pediatric intensive care unit (PICU) for short-term outcome (survival vs. nonsurvival when leaving the PICU). The records of 36 children with a median age of 5 years (range: 0.5 to 21) between August 2004 and August 2007 were reviewed. Mortality rate was 55%, higher than the yearly overall PICU mortality rate of 12% (P<0.0001). The mean Pediatric Risk of Mortality Score (PRISM) III score among survivors was lower than that among nonsurvivors (9.4+/-5.7 vs. 16.4+/-5.3, P=0.001). Comparison of observed and predicted mortality derived from the PRISM III score showed that distribution of outcome was not different and the prediction model performed well (goodness of fit test: chi=3.64, df=6, P=0.725). The mortality rates were 66.6% and 33.3% in patients with high (>10 points) and low (< or =10 points) PRISM III score, respectively (P=0.05). Mortality rate was significantly related to presence and number of organ system dysfunction (P=0.031 and P=0.013, respectively), sepsis (P=0.05), mechanical ventilation (P=0.005), and positive inotropic support (P=0.003). By using multiple logistic regressions, the independent risk factor was PRISM III score at the time of admission to PICU (P=0.05). The PRISM III score performed well as a predictor of outcome. For decision to admit such patients to the PICU or to forgo life-sustaining therapies, other factors such as need for mechanical ventilation and positive inotropic support, presence and numbers of organ system dysfunction should be taken into consideration as well.

Better posttransplant outcome with fludarabine based conditioning in multitransfused fanconi anemia patients who underwent peripheral blood stem cell transplantation.

Several investigators have been looking for less toxic conditioning regimen for stem cell transplantation in Fanconi anemia (FA) patients because of sensitivity to DNA cross-linking agents and tendency to malignancy. We report 16 multitransfused FA patients who underwent peripheral stem cell transplantation from 13 related and 3 unrelated donors. Although the first 6 patients received thoraco-abdominal irradiation + cyclophosphamide + antithymocyte globulin (regimen A) for conditioning, fludarabine (FLU) + cyclophosphamide + antithymocyte globulin (regimen B) were used in the last 10 patients in which 3 of them received unrelated graft. Cyclosporin A was given alone for the related allografts but also included mycophenolate mofetil for the unrelated allograft as graft versus host disease prophylaxis. We observed a lower risk of peritransplant morbidity and mortality with fewer and milder graft versus host disease in FLU based group. We lost 3 patients in regimen A group and 1 of them from secondary acute myeloid leukemia. Three patients are alive with transfusion independent. In regimen B group, 9 of 10 patients are alive with normal hematologic parameters and full donor chimerism. The longest follow-up durations are 90 and 60 months in regimen A and B, respectively. In conclusion, FLU based conditioning is more effective and successful with lower toxicity in multitransfused FA patients. However, it needs more experience and longer follow up duration.

Piperacillin/tazobactam versus cefepime for the empirical treatment of pediatric cancer patients with neutropenia and fever: a randomized and open-label study.

OBJECTIVES: This is a prospective, randomized, and open-label clinical trial that examines the efficiency and safety of PIP/TAZO monotherapy in comparison to cefepime (CEF), for the empirical treatment of pediatric cancer patients with neutropenia and fever. METHODS: One hundred thirty-one consecutive febrile episodes in 70 neutropenic pediatric cancer patients received randomized treatment either with piperacillin/tazobactam (PIP/TAZO) 80 mg/kg piperacillin/10 mg/kg tazobactam every 6 hr or CEF 50 mg/kg every 8 hr. Clinical response was determined at completion of therapy. Duration of fever, neutropenia, hospitalization, the need for modification of the therapy, and mortality rates were compared between the two groups. RESULTS: One hundred twenty-seven episodes in 69 patients (35 females, 34 males) with a median age of 4.2 years were assessed for efficiency (65 PIP/TAZO, 62 CEF). The frequency of success without modification of treatment was nearly identical for both PIP/TAZO (60.0%) and CEF (61.3%) (P > 0.05). The overall response rate, with or without modification of assigned treatment, was 96.9% for PIP/TAZO and 98.4% for CEP (P > 0.05). Infection-related mortality at the end of the febrile episode was 2.4%. Duration of fever and hospitalization were not different between the treatment groups. No major side effects were observed in neither of the groups. CONCLUSIONS: PIP/TAZO treatment was as effective and safe as CEF monotherapy as an initial empirical regimen in pediatric cancer patients with fever and neutropenia.