Vancomycin in Pediatric Patients with Solid or Hematological Malignant Disease: Predictive Performance of a Population Pharmacokinetic Model and New Optimized Dosing Regimens.

BACKGROUND: The application of population pharmacokinetic models and Bayesian methods offers the potential to develop individualized therapeutic approaches. OBJECTIVES: The current study presents an external evaluation of a vancomycin pharmacokinetic model in a pediatric cancer population and proposes an easy-to-use chart for clinicians for a priori vancomycin schedule adaptation to achieve target concentration. METHODS: External evaluation of a population pharmacokinetic model of vancomycin administered via continuous infusion was realized in a new retrospective dataset of pediatric patients with cancer. The published population pharmacokinetic model was implemented in NONMEM 7.3 with the structural and variance parameter values set equal to estimates previously reported. Predictive performance was assessed by quantifying bias and accuracy of model prediction. Normalized prediction distribution errors were also evaluated. Dosage simulations were performed according to the target concentration. RESULTS: A total of 77 patients were included in this study, representing 146 vancomycin courses and 289 concentrations. The model adequately predicted vancomycin concentrations (median prediction error % of - 9.4%, median |PE|% of 24.1%). Based on simulation results, vancomycin dosage (mg/kg) should be adapted for each child on the basis of body weight and cyclosporine coadministration. CONCLUSION: The model previously proposed by Guilhaumou et al. in pediatric patients with solid or hematological malignant disease was externally validated. Simulations have enabled the description of new dosage schedules and creation of a chart to help clinicians adapt vancomycin dosage.

Outcome after failure of allogeneic hematopoietic stem cell transplantation in children with acute leukemia: a study by the société Francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Allogeneic hematopoietic stem cell transplantation (SCT) contributes to improved outcome in childhood acute leukemia (AL). However, therapeutic options are poorly defined in the case of post-transplantation relapse. We aimed to compare treatment strategies in 334 consecutive children with acute leukemia relapse or progression after SCT in a recent 10-year period. Data could be analyzed in 288 patients (157 ALL, 123 AML and 8 biphenotypic AL) with a median age of 8.16 years at transplantation. The median delay from first SCT to relapse or progression was 182 days. The treatment consisted of chemotherapy alone (n=108), chemotherapy followed by second SCT (n=70), supportive/palliative care (n=67), combination of chemotherapy and donor lymphocyte infusion (DLI; n=30), or isolated reinfusion of donor lymphocytes (DLI; n=13). The median OS duration after relapse was 164 days and differed according to therapy: DLI after chemotherapy=385 days, second allograft=391 days, chemotherapy=174 days, DLI alone=140 days, palliative care=43 days. A second SCT or a combination of chemotherapy and DLI yielded similar outcome (hazard ratio (HR)=0.85, P=0.53) unlike chemotherapy alone (HR=1.43 P=0.04), palliative care (HR=4.24, P<0.0001) or isolated DLI (HR=1,94, P<0.04). Despite limitations in this retrospective setting, strategies including immunointervention appear superior to other approaches, mostly in AML.

Cytogenetics and outcome of allogeneic transplantation in first remission of acute myeloid leukemia: the French pediatric experience.

We analyzed the impact of cytogenetics on 193 children enrolled in two successive French trials (LAME89/91 and ELAM02), who received hematopoietic stem cell transplantation during CR1. Detailed karyotype was available for 66/74 (89%) in LAME89/91 and 118/119 (99%) in ELAM02. Several karyotype and transplant characteristics differed according to therapeutic protocol: unfavorable karyotypes were more frequent in ELAM02 (36% vs 18%), pretransplant chemotherapy included high-dose cytarabine in ELAM02 and not in LAME89/91, IV replaced oral busulfan in the conditioning regimen, methotrexate was removed from post-transplant immunosuppression, and matched unrelated donor and cord blood transplantation were introduced. Five-year overall survival (OS) was 78.2% in LAME89 and 81.4% in ELAM02. OS was significantly lower for the unfavorable cytogenetic risk group in LAME89/91 when compared with intermediate and favorable groups (50% vs 90.6 and 86.4%, P=0.001). This difference was no longer apparent in ELAM02 (80.9% vs 71.3% and 5/5, respectively). Survival improvement for children with unfavorable karyotype was statistically significant (P=0.026) and was due to decrease in relapse risk. Five-year transplantation-related mortality was 6.75% in LAME89/91. In ELAM02, it was 3.2% for patients with a sibling donor and 10.9% with an unrelated donor or cord blood. We conclude that the outcome of children with unfavorable karyotype transplanted in CR1 has improved.

[Impact of anti-HLA antibodies on outcomes of allogeneic stem cell transplantation: a report by the SFGM-TC]. / Impact des anticorps anti-HLA sur le devenir de l'allogreffe de cellules souches hématopoïétiques : un rapport par la SFGM-TC.

The role of anti-HLA antibodies in allogeneic stem cell transplantation setting is still unclear. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. This article offers the recommendations of the group that considered the impact that have anti-HLA antibodies on outcomes in allogeneic stem cell transplantation.

Health status of childhood leukemia survivors who received hematopoietic cell transplantation after BU or TBI: an LEA study.

The purpose of this multicenter study was to compare the long-term impact of a preparative regimen with either BUBU or TBI on health status and quality of life (QoL) in childhood acute leukemia survivors treated with hematopoietic SCT (HSCT). Two-hundred and forty patients were included. Sixty-six had received BU, while 174 had received TBI. Median follow-up from HSCT was 10.1 years. Multivariate analyses were performed to assess the occurrence of late effects according to treatment. QoL was assessed in 130 adults using SF-36 questionnaires. Patients developed fewer late complications after BU (2.35 vs 3.01, P=0.03) while the risk to present with at least one complication was equivalent in both groups (87.9% after BU and 93.1% after TBI, P=0.66). Detailed multivariate analyses revealed a lower risk of height growth failure (OR=0.2), cataract (OR=0.1) and iron overload (OR=0.2) after BU, and an increased risk of overweight (OR=3.9) and alopecia (OR=11.2). SF-36 mental and physical composite scores were similar in both treatment groups and proved significantly lower than French norms. Late effects induced by BU might differ from those experienced after TBI. Although less frequent, they are still of considerable importance and may affect patients' QoL.

Impact on long-term OS of conditioning regimen in allogeneic BMT for children with AML in first CR: TBI+CY versus BU+CY: a report from the Société Française de Greffe de Moelle et de Thérapie Cellulaire.

Allogeneic hematopoietic SCT (HSCT) appears to be an efficient tool to cure high-risk AML in first CR but the choice between BU-based or TBI-based conditioning regimens still remains controversial. In order to analyze the impact of conditioning regimen on long-term survival, we conducted a retrospective analysis from French registry data including all consecutive patients under 18 years old (n=226) from 1980 to 2004 transplanted for AML in CR1 from sibling (n=142) or matched unrelated donors and given either TBI-1200 cGy and CY 120 mg/kg (TBI-Cy, n=84) or BU 16 mg/kg and CY 200 mg/kg (BuCy200, n=142). Patient subgroups were comparable for all criteria except for median age at diagnosis and HSCT and for donor type. Both 5-year OS and disease-free survival (DFS) were significantly better in BuCy200 group (P=0.02 and 0.005, respectively). In multivariate analysis, both HLA matching and BuCy200 appeared as good prognostic factors for treatment-related mortality and DFS. Grade 2-4 acute GvHD and chronic GvHD rates were statistically higher in TBI-Cy group than in Bu-Cy200 one with a RR at 2 (P=0.002). In total, Bu-Cy200 conditioning regimen gives better outcome compared with TBI-Cy irrespective of the stem cell source and the donor type.

Double reduced-intensity allogeneic hematopoietic stem cell transplantation: a retrospective study from the SFGM-TC.

The purpose of this paper is to describe the outcome of patients who underwent double allogeneic hematopoietic stem cell transplantation (AHSCT) with reduced-intensity conditioning regimens (RIC). Forty-five patients who received double RIC-AHSCT between 1997 and 2006 were retrospectively studied. The predominant diagnosis was acute myeloid leukemia (AML) (n = 17). Other diagnoses were aplasic anemia (AA) (n = 5), myelodysplasic disorder (n = 5), acute lymphoblastic leukemia (ALL) (n = 4), chronic myelomonocytic leukemia (CML) (n = 3), myeloma (n = 3), non-Hodgkin lymphoma (NHL) (n = 3), chronic lymphocytic leukemia (CLL) (n = 2), Hodgkin's disease (HD) (n = 2), and chronic myelomonocytic leukemia (n = 1). Main indications for RIC-AHSCT 2 were relapse (n = 25, 56%) and early (n = 8, 18%) or late (n = 12, 26%) graft failure. Median delays to reach a neutrophil count of 0.5 × 10(9)/L and platelet counts of 50 × 10(9)/L were significantly smaller after the second AHSCT. Among 25 patients who relapsed after RIC-AHSCT 1, 14 patients (56%) presented a response improvement after RIC-AHSCT 2. In this group, 9 patients sustained a complete response and 5 patients a partial response. Moreover, among the 20 patients who had early or late graft failure following RIC-AHSCT 1, 9 (45%) finally reached an engraftment. Disease-free survival (DFS) was significantly improved after RIC-AHSCT 2. Thirteen patients (28%) died of transplant-related mortality (TRM) at a median delay of 69 days (range: 0-451) after RIC-AHSCT 2. Double RIC-AHSCT is a feasible procedure that allows a response or engraftment not observed after RIC-AHSCT 1. The main indication is relapse. However, TRM remains high.

Germline mutations of the CBL gene define a new genetic syndrome with predisposition to juvenile myelomonocytic leukaemia.

BACKGROUND: CBL missense mutations have recently been associated with juvenile myelomonocytic leukaemia (JMML), an aggressive myeloproliferative and myelodysplastic neoplasm of early childhood characterised by excessive macrophage/monocyte proliferation. CBL, an E3 ubiquitin ligase and a multi-adaptor protein, controls proliferative signalling networks by downregulating the growth factor receptor signalling cascades in various cell types. METHODS AND RESULTS: CBL mutations were screened in 65 patients with JMML. A homozygous mutation of CBL was found in leukaemic cells of 4/65 (6%) patients. In all cases, copy neutral loss of heterozygosity of the 11q23 chromosomal region, encompassing the CBL locus, was demonstrated. Three of these four patients displayed additional features suggestive of an underlying developmental condition. A heterozygous germline CBL p.Y371H substitution was found in each of them and was inherited from the father in one patient. The germline mutation represents the first hit, with somatic loss of heterozygosity being the second hit positively selected in JMML cells. The three patients display a variable combination of dysmorphic features, hyperpigmented skin lesions and microcephaly that enable a 'CBL syndrome' to be tentatively delineated. Learning difficulties and postnatal growth retardation may be part of the phenotype. CONCLUSION: A report of germline mutations of CBL in three patients with JMML is presented here, confirming the existence of an unreported inheritable condition associated with a predisposition to JMML.

Invasive aspergillosis and allogeneic hematopoietic stem cell transplantation in children: a 15-year experience.

Despite progress in diagnosis and treatment, invasive aspergillosis (IA) remains a principal cause of mortality due to infection after allogeneic hematopoietic stem cell transplantation (AHSCT). In order to clarify the course of IA among children receiving an AHSCT before the advent of new drugs such as voriconazole or caspofungin, we retrospectively reviewed the medical records of all proven and probable IA between January 1986 and December 2000. 1) Ten children developed IA after AHSCT, mostly long after transplantation. Overall incidence was 2.7%. Seven of those children experienced 1 or more complications after AHSCT and before IA. Mortality was 90% with a median survival of 23 days (2-90). 2) Five children underwent AHSCT after a previous episode of IA. All patients were treated with systemic antifungal therapy combined with surgery. Median time between IA and AHSCT was 110 days (73-370). Two children were diagnosed with IA relapse after transplantation. One child was cured while the other died of IA and AHSCT complications. AHSCT could be considered even in the setting of previous IA, but established strategies implementing newer less toxic antifungal agents as treatment or prophylaxis in high-risk patients are needed.

Prospective validation of a novel IV busulfan fixed dosing for paediatric patients to improve therapeutic AUC targeting without drug monitoring.

INTRODUCTION: Oral busulfan clearance is age-dependent and children experience a wide variability in plasma exposure. BSA- or age-based dosing is used with therapeutic drug monitoring (TDM) to reduce this variability. PURPOSE: A new intravenous (IV) dosing of busulfan (Bu) based on body weight, designed to improve AUC targeting without TDM and dose-adjustment, was prospectively evaluated. METHOD: Bu was administered as a 2 h IV infusion every 6 h over 4 days (16 administrations). Five dose levels were defined on body weight as follows: 1.0 mg/kg for <9 kg; 1.2 mg/kg for 9 to <16 kg; 1.1 mg/kg for 16-23 kg; 0.95 mg/kg for >23-34 kg; 0.80 mg/kg for >34 kg. Bu treatment was followed by Cyclophosphamide or Melphalan prior to allogeneic or autologous transplantation in 55 children aged 0.3-17.2 years (median 5.6 years). RESULTS: No difference in AUC values was observed between weight strata (mean +/- SD 1248 +/- 205 micromol.min), whereas a significant difference in Bu clearance was demonstrated. This new dosing enabled to achieve a mean exposure comparable to that in adults. At dose 1, 91% of patients achieved the targeted AUC range (900-1500 micromol.min) while no patients were underexposed. At doses 9 and 13, over 75% of patients remained within that target whilst most of the others were slightly above. Successful engraftment was achieved in all patients. In conclusion, from infants to adults this new dosing enabled, without TDM and dose adjustment, to successfully target a therapeutic AUC window.

Influence of underlying disease on busulfan disposition in pediatric bone marrow transplant recipients: a nonparametric population pharmacokinetic study.

Busulfan is an alkylating agent used in a conditioning regimen prior to bone marrow transplantation. Busulfan has a narrow therapeutic index, giving rise to major liver toxicity (veno-occlusive disease), and a wide interpatient and intrapatient pharmacokinetic variability. This report presents the results of a population pharmacokinetic analysis leading to models based on underlying diseases requiring bone marrow transplantation. One hundred children received oral busulfan-based conditioning regimens between March 1998 and February 2006. Busulfan pharmacokinetic parameter estimates (Ka, first order absorption rate constant; Vs, volume of distribution related to the body weight; and Cl/F, apparent clearance) were estimated by using the nonparametric adaptative grid (NPAG) algorithm in patients divided into four groups according to initial diagnosis: metabolic diseases, hemoglobinopathies, hematological malignancies, and immune deficiencies. Ka and Vs did no differ significantly in the four subgroups. Cl/F and areas under the plasma concentration curve were significantly different in the four groups. Cl/F was significantly higher in the hemoglobinopathies group (P = 0.002), with a mean value of 7.78 L . h, whereas the immune deficiencies group was characterized by the lowest Cl/F (3.59 L . h). Interindividual variability was shown by high interindividual parameter percent coefficients of variation (CV%) but, nevertheless, with less diversity in the population parameter distributions for Vs in the three subgroups-metabolic diseases, hemoglobinopathies, and malignant diseases-and in Cl/F for patients with hemoglobinopathies. The fit was good for busulfan concentration predictions based on Bayesian individual posterior values, with little bias and good precision. In comparison with the overall population, the only model of subgroup presenting a greater precision was patients with hemoglobinopathies (P = 0.002). Use of these more specific models of a given disease may well result in more accurate individualization of busulfan dose regimens, especially in very sparse blood sampling situations.

Overexpression of the antiapoptotic gene Bfl-1 in B cells from patients with familial systemic lupus erythematosus.

Genetic determinants taking part in the development of systemic lupus erythematosus (SLE) are complex and not fully characterized. Dysregulated expression of genes involved in the control of apoptosis has been previously suggested. We report here a consanguineous family with SLE manifestations in three siblings associated in one of them with severe lymphoproliferative features. Laboratory studies showed no defect in CD95-mediated cell death. Screening expression of Bcl-2 family genes that regulate mitochondrial apoptosis pathway showed an overexpression of the antiapoptotic Bfl-1 gene. Real time RT-PCR analysis indicated that overexpression of Bfl-1 was restricted to B-cells, with normal expression in T-cells. Those results suggest that overexpression of Bfl-1 could result in impaired B-lymphocyte homeostasis and inappropriate immune response leading to autoimmune manifestations.

Impact of cumulative anthracycline dose, preparative regimen and chronic graft-versus-host disease on pulmonary and cardiac function in children 5 years after allogeneic hematopoietic stem cell transplantation: a prospective evaluation on behalf of the EBMT Pediatric Diseases and Late Effects Working Parties.

This prospective study focused on risk factors and clinical outcome of pulmonary and cardiac late effects after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We prospectively evaluated 162 children by pulmonary function tests (PFTs) and cardiac shortening fraction (SF) before allo-HSCT and yearly up to the 5th year of follow-up. The 5-year cumulative incidence of lung and cardiac impairment was 35 (hazard rate=0.03) and 26% (hazard rate=0.06), respectively. Patients presenting abnormal PFTs and SF at last follow-up were 19 and 13%, respectively, with a median Lansky performance status of 90% (70-100). Chronic graft-versus-host disease (c-GVHD) was the major risk factor for reduced lung function in univariate (P=0.02) and multivariate analysis (P=0.02). Total body irradiation (TBI) alone and TBI together with pre-transplant anthracycline administration were significant risk factors for reduced cardiac function in univariate analysis, only (P=0.04 and 0.004, respectively). In conclusion, our prospective study demonstrates an asymptomatic post-allo-HSCT deterioration of pulmonary and cardiac function in some long-term survivors, who had been transplanted in childhood, and thus emphasizes the need for lifelong cardiopulmonary monitoring and the development of new strategies both to reduce pre-transplant cardiotoxic regimens and to treat more efficiently c-GVHD.

[Human herpesvirus 6 encephalitis after bone marrow transplantation]. / Un cas d'encéphalite à herpès virus humain de type 6 après transplantation de moelle osseuse.

Human herpesvirus 6 (HHV-6) encephalitis may induce neurological sequelae and death; the diagnosis is difficult because of an initially poor symptomatology and of the absence of specific biochemical, electric and radiological signs. We report on a 7-year-old boy with relapsed acute lymphoblastic leukaemia, who developed HHV-6 encephalitis after bone marrow transplantation; the patient recovered after treatment with ganciclovir.

[Childhood cancer incidence and survival rates in the Rhône-Alpes regional paediatric registry 1987-1999]. / Les cancers de l'enfant de la région Rhône-Alpes: incidence et survie 1987-1999.

UNLABELLED: Cancer is rare in children, and pediatric malignancies represent only 1% of all cancers. OBJECTIVES: The cure rate is high and increasing, and ongoing data collection is therefore warranted. MATERIALS AND METHODS: Here we report the incidence and survival rates of childhood cancers between 1987 and 1999 in the Rhône-Alpes region of France. RESULTS: A total of 1945 cases were recorded during the study period, with an average of 149.6 new cases per year. The approximate incidence rate was 134.1/10(6) per year and the age-standardized incidence rate was 139.2/10(6) per year. The histological distribution and 5-year survival rates were respectively 30.2 and 73% for leukemia, 12.3 and 91.6% for lymphoma, 24.7 and 60.1% for CNS tumors, 9.1 and 71.1% for neuroblastoma, 2.5 and 94.1% for retinoblastoma, 5.8% and 89.9% for renal tumors, 1 and 75% for liver tumors, 6.1 and 60.9% for bone tumors, 4.1 and 58.6% for soft-tissue tumors, 1.1 and 71% for germ cell tumors, and 2.4 and 85.1% for carcinomas. CONCLUSION: The overall survival rate was 75%. Long-term treatment complications warrant further studies of children who survive into adulthood.

Low incidence of sepsis due to viridans streptococci in a ten-year retrospective study of pediatric acute myeloid leukemia.

BACKGROUND: Infections remain an important cause of morbidity and mortality in children with acute myeloid leukemia (AML), and particularly viridans group streptococci (VGS) sepsis. The present study, conducted between 1993 and 2003 in children with AML, sought to assess the frequency and characteristics of infectious complications (ICs), the incidence of VGS sepsis, the interest of preventive decontamination, and a possible cytarabine dose-effect on the occurrence of ICs. METHODS: Medical charts of 78 children treated according to the EORTC 58921 clinical trial were analyzed retrospectively. Patients were isolated in laminar air flow rooms, received non-absorbable gut decontamination, gum decontamination with vancomycin mouthwash, and trimethoprim-sulfamethoxasole. ICs were categorized as microbiologically documented infections (MDI), clinically documented infections (CDI), or fever of unknown origin (FUO). RESULTS: Overall, 268 ICs occurred: 57.5% FUO, 8.5% CDI, and 34% MDI. Bloodstream infections occurred in 58 febrile episodes: Gram-positive bacteria represented 83% of the pathogens including 66.1% Staphylococcus species and 8.5% Streptococcus species (6.8% VGS), Gram-negative bacteria represented 13.5% of the pathogens and yeasts 3.5%. Five patients died of infection (6.4%). None died from bacterial infection and no case of VGS sepsis required intensive care. Invasive fungal infection was proven in four patients. Number of ICs was significantly different according to gum and gut decontamination status, and according to the cytarabine dose during the first intensification. No resistant strains were detected in spite of the use of local antibiotics. CONCLUSION: The low rate of VGS and enterobacteriaceae sepsis was probably due to the effective decontamination. Our supportive care strategy could potentially help enhance overall survival in children with AML.

[Five cases of trichobezoars in children]. / Trichobézoard: à propos de 5 observations.

Trichobezoars are made up of concretions of ingested hair and food. A history of occlusive syndrome in a context of trichotillomania and psychological problems must lead to this diagnosis. Bezoars can be fortuitously recognised by palpation of an epigastric abdominal mass while investigating anemia or esophageal reflux. This deviance is particularly dangerous. The first case of this series illustrates the Rapunzel syndrome with many perforations and necrosis of the small bowel. The 4 others are strict intragastric bezoars, quickly identified by echography. Treatment is exclusively surgical, digestion by papain or endoscopic extraction being impossible. Psychological assistance is mandatory.