Hulya Ozsahin

Defibrotide for prophylaxis of hepatic veno-occlusive disease in paediatric haemopoietic stem-cell transplantation: an open-label, phase 3, randomised controlled trial

BACKGROUND Hepatic veno-occlusive disease is a leading cause of morbidity and mortality after haemopoietic stem-cell transplantation (HSCT). We aimed to assess whether defibrotide can reduce the incidence of veno-occlusive disease in this setting. METHODS In our phase 3 open-label, randomised controlled trial, we enrolled patients at 28 European university hospitals or academic medical centres. Eligible patients were younger than 18 years, had undergone myeloablative conditioning before allogeneic or autologous HSCT, and had one or more risk factor for veno-occlusive disease based on modified Seattle criteria. We centrally assigned eligible participants on the basis of a computer-generated randomisation sequence (1:1), stratified by centre and presence of osteopetrosis, to receive intravenous defibrotide prophylaxis (treatment group) or not (control group). The primary endpoint was incidence of veno-occlusive disease by 30 days after HSCT, adjudicated by a masked, independent review committee, in eligible patients who consented to randomisation (intention-to-treat population), and was assessed with a competing risk approach. Patients in either group who developed veno-occlusive disease received defibrotide for treatment. We assessed adverse events to 180 days after HSCT in all patients who received allocated prophylaxis. This trial is registered with ClinicalTrials.gov, number NCT00272948. FINDINGS Between Jan 25, 2006, and Jan 29, 2009, we enrolled 356 eligible patients to the intention-to-treat population. 22 (12%) of 180 patients randomly allocated to the defibrotide group had veno-occlusive disease by 30 days after HSCT compared with 35 (20%) of 176 controls (risk difference -7·7%, 95% CI -15·3 to -0·1; Z test for competing risk analysis p=0·0488; log-rank test p=0·0507). 154 (87%) of 177 patients in the defibrotide group had adverse events by day 180 compared with 155 (88%) of 176 controls. INTERPRETATION Defibrotide prophylaxis seems to reduce incidence of veno-occlusive disease and is well tolerated. Thus, such prophylaxis could present a useful clinical option for this serious complication of HSCT. FUNDING Gentium SpA, European Group for Blood and Marrow Transplantation.

Rapid assay of intrinsic radiosensitivity based on apoptosis in human CD4 and CD8 T-lymphocytes☆

PURPOSE An assay for radiosensitivity has numerous applications in the clinic. Avoidance of acute responses, prediction of normal tissue toxicity, and individualization of patient radiotherapy are included among these. We have developed a rapid assay (about 24 h) able to predict intrinsic radiosensitivity of CD4 and CD8 T-lymphocytes based on radiation-induced apoptosis. METHODS AND MATERIALS Fresh blood samples (1-2 ml in heparinized tubes) were irradiated with 0-, 2-, and 8-Gy X rays at a dose rate of approximately 3 Gy/min. Following irradiation, the cells were collected and prepared for flow-cytometric analysis and cell sorting. In conjunction with the CellQuest software available with the FACSVantage cell sorter (Becton-Dickinson), two T-lymphocyte types were analyzed on the basis of their cell-specific antigens (CD4 and CD8), and DNA was stained with DAPI. Following the separation of these cell types, radiation-induced cell death was assessed. Cytotoxicity was characterized by gradual degradation of internucleosomal DNA which results in a sub-G1 peak on the DNA histogram, and by the associated loss of surface antigens causing an intermediate positive peak in the antibody histogram. Using the assay, we investigated the interdonor variation in a cohort of 45 healthy adult blood donors and 5 children [one had immunodeficiency, centromeric instability, and facial anomalies syndrome (ICF), and one had ataxia telangiectasia (AT)]. Intradonor variation was assessed with 10 different experiments from a single donor. RESULTS CD4 and CD8 T-lymphocyte radiosensitivities were correlated (r = 0.63 and 0.65 for 2 and 8 Gy, respectively) in 45 adult donors. Both for CD4 and CD8 cells, 2 and 8 Gy irradiation responses showed a good correlation (r = 0.77 for both). Interdonor variation was significantly higher than intradonor variation (p < 0.0005) for all CD4 and CD8 data. We observed a decrease in the antigen fluorescence of dying cells, a phenomenon referred to as antigen-ebb. Antigen-ebb was clearly observed in both cell types, and correlated significantly with cytotoxicity. A trend was observed between radiosensitivity and donor age, but there was no correlation for gender. Blood from a 4-year-old girl presenting with ICF demonstrated compromised radiation-induced cytotoxicity in her CD4 T-lymphocytes, and an 11-year-old boy presenting with AT demonstrated compromised radiation-induced cytotoxicity in both his CD4 and CD8 T-lymphocytes. CONCLUSION We conclude that the assay provides a rapid means of determining radiosensitivity, can discriminate differences in radiation-induced cytotoxicity between individuals, and can be used as a rapid screen for genetically hypersensitive patients. Antigen-ebb offers interesting possibilities for molecular biological investigations, permitting characterization and isolation of abnormal but vital cells in the absence of clastogenic agents.

Bone marrow transplantation in 26 patients with Wiskott-Aldrich syndrome from a single center

We retrospectively analyzed the outcome of bone marrow transplantation (BMT) performed in 26 patients with Wiskott-Aldrich syndrome (WAS) in one center. Twenty-eight transplantation procedures were performed. Ten unselected patients received unmanipulated marrow from a donor with genetically identical human leukocyte antigen (HLA). Eight patients were cured and survive 1.5 to 16.5 years after BMT. One patient successfully received a T-cell-depleted marrow from a matched unrelated donor. Sixteen patients were selected to receive a related HLA partially incompatible BMT because of the occurrence of life-threatening complications from the WAS (i.e., refractory thrombocytopenia, autoimmunity including vasculitis and sepsis). All but one received T-cell-depleted marrow after a conditioning regimen of busulfan and cyclophosphamide. One patient had two BMTs. Engraftment occurred in 12 of 17 attempts. The addition of monoclonal antibodies to lymphocyte function-associated antigen-1 and CD2 molecules appeared to improve engraftment. Six patients were long-term survivors, whereas others died of viral infections (n = 7), among which Epstein-Barr virus-induced B-lymphocyte proliferative disorder was predominant. Delay in development of full T- and B-cell functions accounted for severe infectious complications. These results confirm the excellent outcome of HLA genetically identical BMT in WAS, whereas BMT from HLA partially incompatible donors should be strictly restricted to patients with severe complications of WAS.

Predicting Adverse Events in Children With Fever and Chemotherapy-Induced Neutropenia: The Prospective Multicenter SPOG 2003 FN Study

PURPOSE To develop a score predicting the risk of adverse events (AEs) in pediatric patients with cancer who experience fever and neutropenia (FN) and to evaluate its performance. PATIENTS AND METHODS Pediatric patients with cancer presenting with FN induced by nonmyeloablative chemotherapy were observed in a prospective multicenter study. A score predicting the risk of future AEs (ie, serious medical complication, microbiologically defined infection, radiologically confirmed pneumonia) was developed from a multivariate mixed logistic regression model. Its cross-validated predictive performance was compared with that of published risk prediction rules. Results An AE was reported in 122 (29%) of 423 FN episodes. In 57 episodes (13%), the first AE was known only after reassessment after 8 to 24 hours of inpatient management. Predicting AE at reassessment was better than prediction at presentation with FN. A differential leukocyte count did not increase the predictive performance. The score predicting future AE in 358 episodes without known AE at reassessment used the following four variables: preceding chemotherapy more intensive than acute lymphoblastic leukemia maintenance (weight = 4), hemoglobin > or = 90 g/L (weight = 5), leukocyte count less than 0.3 G/L (weight = 3), and platelet count less than 50 G/L (weight = 3). A score (sum of weights) > or = 9 predicted future AEs. The cross-validated performance of this score exceeded the performance of published risk prediction rules. At an overall sensitivity of 92%, 35% of the episodes were classified as low risk, with a specificity of 45% and a negative predictive value of 93%. CONCLUSION This score, based on four routinely accessible characteristics, accurately identifies pediatric patients with cancer with FN at risk for AEs after reassessment.

Sources of variation in patient response to radiation treatment

PURPOSE To investigate sources of variation in radiosensitivity displayed by cancer patients and blood donors using the leukocyte apoptosis assay. METHODS AND MATERIALS Probes were obtained from 105 healthy blood donors, 48 cancer patients displaying normal sensitivity to radiotherapy, 12 cancer patients displaying hypersensitivity to radiotherapy, 12 Ataxia telangiectasia blood donors, and 4 additional individuals with genetic diseases of potentially modified radiosensitivity; 2 neurofibromatosis (NF) donors, a Nijmegen breakage syndrome (NBS) donor, and an Immunodeficiency, Chromosome fragility, Facial anomaly syndrome (ICF) donor. Heparinized blood was diluted in medium, irradiated, and left to incubate for 48 h. CD4 and CD8 T-lymphocyte DNA was stained with propidium iodide and the cells were analyzed by flow cytometry. RESULTS Radiation-induced apoptosis depended on age and cell type. Cohorts of hypersensitive cancer patients, NBS and AT donors displayed compromised apoptotic response. An asymmetric apoptotic response of T-lymphocytes was observed in an ICF donor and a cryptic hypersensitivity donor. Two NF donors displayed no abnormal sensitivity to radiotherapy but compromised apoptotic T-cell response to X-rays. CONCLUSION Our studies reveal 4 physiologic sources of variation in radiation response-2 are genetic: cryptic hypersensitivity and hereditary disease, and 2 are epigenetic: cell type and donor age. They emphasize the important role of proteins involved in the recognition and repair of DNA double-strand breaks in determining the response of individuals to radiotherapy.

Anti-protein S antibodies following a varicella infection: detection, characterization and influence on thrombin generation

Summary.  Postinfectious purpura fulminans is a rare disease. Varicella is one of the precipitating conditions and we recently observed such a case. The 4‐year‐old child was found to have a severe transient protein S deficiency. By enzyme‐linked immunosorbent assay and surface plasmon resonance we first demonstrated that anti‐protein S antibodies were present and also transient. Next we characterized the epitopes against which these antibodies were directed and found that they predominantly recognized the N‐terminal part of protein S. Finally we showed by thrombography a transient dramatic hypercoagulable state as a result of thrombin being unregulated by the dynamic protein C inhibitory system: in vitro thrombin generation, in response to a low concentration of tissue factor, was almost insensitive to activated protein C up to 25 nmol L−1 on day 4 while it was normally sensitive on day 42. For the first time, we demonstrated a temporal relationship between protein S deficiency, antibodies to protein S and hypercoagulability, thus supporting the pathogenic role of these antibodies.

Obesity in long-term survivors of childhood acute lymphoblastic leukemia.

Childhood acute lymphoblastic leukemia (ALL) with current cure rates reaching 80% emphasizes the necessity to determine treatment related long‐term effects. The present study examines the prevalence of and the risk factors for overweight and obesity in a cohort of ALL survivors treated and living in the French speaking part of Switzerland.

Predicting bacteremia in children with cancer and fever in chemotherapy-induced neutropenia : results of the prospective multicenter SPOG 2003 FN study

Study Aim: To develop a score predicting the risk of bacteremia in cancer patients with fever and neutropenia (FN), and to evaluate its performance. Methods: Pediatric patients with cancer presenting with FN induced by nonmyeloablative chemotherapy were observed in a prospective multicenter study. A score predicting the risk of bacteremia was developed from a multivariate mixed logistic regression model. Its cross-validated predictive performance was compared with that of published risk prediction rules. Results: Bacteremia was reported in 67 (16%) of 423 FN episodes. In 34 episodes (8%), bacteremia became known only after reassessment after 8 to 24 hours of inpatient management. Predicting bacteremia at reassessment was better than prediction at presentation with FN. A differential leukocyte count did not increase the predictive performance. The reassessment score predicting future bacteremia in 390 episodes without known bacteremia used the following 4 variables: hemoglobin ≥90 g/L at presentation (weight 3), platelet count <50 G/L (3), shaking chills (5), and other need for inpatient treatment or observation according to the treating physician (3). Applying a threshold ≥3, the score—simplified into a low-risk checklist—predicted bacteremia with 100% sensitivity, with 54 episodes (13%) classified as low-risk, and a specificity of 15%. Conclusions: This reassessment score, simplified into a low-risk checklist of 4 routinely accessible characteristics, identifies pediatric patients with FN at risk for bacteremia. It has the potential to contribute to the reduction of use of antimicrobials in, and to shorten the length of hospital stays of pediatric patients with cancer and FN.

Bone marrow transplantation in cartilage-hair hypoplasia: Correction of the immunodeficiency but not of the chondrodysplasia

AbstractWe diagnosed cartilagehair hypoplasia (CHH) in a female child with prenatal-onset short stature, metaphyseal chondrodysplasia, and severe combined immunodeficiency leading to recurrent, severe respiratory tract infections. The patient required several hospital admissions during her 1st year of life and failed to thrive in spite of antimicrobial therapy and hypercaloric nutrition. Bone marrow transplantation (BMT) from an HLA-identical sister was performed at age 16 months after conditioning with busulphan and cyclophosphamide, using 9×108 nucleated bone marrow cells/kg body weight. Graft-versus-host disase prophylaxis consisted of cyclosporine and methotrexate. The post-transplantation period was uneventful. She developed full and sustained chimerism as demonstrated by DNA analysis of granulocytes and mononucleated cells on days 44, 69 and 455 post BMT. Cellular immunity was completely reconstituted at 4 months, humoral immunity at 15 months post BMT. The patient is alive and well 24 months post BMT without medication, but the radiological osseous changes persist, and longitudinal growth remains markedly below the 10th percentile for CHH standards; her height at age 3 years 4 months is 66 cm.ConslusionsIn this patient with unusually severe CHH, bone-marrow transplantation has fully corected the immune deficiency but has had no influence on the course of the chondrodysplasia.

Natural history of Barth syndrome: a national cohort study of 22 patients

BackgroundThis study describes the natural history of Barth syndrome (BTHS).MethodsThe medical records of all patients with BTHS living in France were identified in multiple sources and reviewed.ResultsWe identified 16 BTHS pedigrees that included 22 patients. TAZ mutations were observed in 15 pedigrees. The estimated incidence of BTHS was 1.5 cases per million births (95%CI: 0.2–2.3). The median age at presentation was 3.1 weeks (range, 0–1.4 years), and the median age at last follow-up was 4.75 years (range, 3–15 years). Eleven patients died at a median age of 5.1 months; 9 deaths were related to cardiomyopathy and 2 to sepsis. The 5-year survival rate was 51%, and no deaths were observed in patients ≥3 years. Fourteen patients presented with cardiomyopathy, and cardiomyopathy was documented in 20 during follow-up. Left ventricular systolic function was very poor during the first year of life and tended to normalize over time. Nineteen patients had neutropenia. Metabolic investigations revealed inconstant moderate 3-methylglutaconic aciduria and plasma arginine levels that were reduced or in the low-normal range. Survival correlated with two prognostic factors: severe neutropenia at diagnosis (<0.5 × 109/L) and birth year. Specifically, the survival rate was 70% for patients born after 2000 and 20% for those born before 2000.ConclusionsThis survey found that BTHS outcome was affected by cardiac events and by a risk of infection that was related to neutropenia. Modern management of heart failure and prevention of infection in infancy may improve the survival of patients with BTHS without the need for heart transplantation.