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E Vilmer

Publications and source records attributed to E Vilmer.

At least 19 recordsLinked to original sources
PubMed2001

Quantification of busulfan in plasma by liquid chromatography-ion spray mass spectrometry. Application to pharmacokinetic studies in children.

Optimisation of busulfan dosage in patients undergoing bone marrow transplantation is recommended in order to reduce toxic effects associated with high drug exposure. A new method was developed coupling liquid chromatography with mass spectrometry (LC-MS) and was validated for the determination of busulfan concentrations in plasma. Recovery was 86.7%, the limit of detection was 2.5 ng/ml and linearity ranged from 5 to 2500 ng/ml. The correlation between the busulfan concentrations measured by our previously published HPLC-UV method and the new HPLC-MS method was highly significant (P<0.0001). Sample volume was reduced and the method was rapid, sensitive and less expensive than the methods previously used in our laboratory. This method was used to determine the pharmacokinetic parameters of busulfan after the first administration of 1 mg/kg orally, in 13 children receiving the drug as part of the preparative regimen for bone marrow transplantation. Our results were similar to previously reported data. They showed that the apparent oral clearance of busulfan was 0.299+/-0.08 l/h/kg, and that it was significantly higher (P=0.02) in patients below the age of 5 years than in older children.

Administration, Oral↗
PubMed2001

Value of high-dose cytarabine during interval therapy of a Berlin-Frankfurt-Munster-based protocol in increased-risk children with acute lymphoblastic leukemia and lymphoblastic lymphoma: results of the European Organization for Research and Treatment of Cancer 58881 randomized phase III trial.

PURPOSE: The European Organization for Research and Treatment of Cancer 58881 study was designed to test in a prospective multicentric randomized trial the value of high-dose (HD) intravenous (IV) cytarabine (Ara-C) added to HD IV methotrexate (MTX) to reduce the incidence of CNS and systemic relapses in children with increased-risk acute lymphoblastic leukemia (ALL) or stage III and IV lymphoblastic lymphoma treated with a Berlin-Frankfurt-Munster (BFM)-based regimen. PATIENTS AND METHODS: After completion of induction-consolidation phase, children with increased-risk (risk factor > 0.8 or T-lineage) ALL or stage III and IV lymphoblastic lymphoma were randomized to receive four courses of HD MTX (5 g/m(2) over 24 hours every 2 weeks) and four intrathecal administrations of MTX (Arm A) or the same treatment schedule with additional HD IV Ara-C (1 g/m(2) in bolus injection 12 and 24 hours after the start of each MTX infusion) (Arm B). RESULTS: Between January 1990 and January 1996, 653 patients with ALL (593 patients) or lymphoblastic lymphoma (60 patients) were randomized: 323 were assigned to Arm A (without Ara-C) and 330 to Arm B (with Ara-C). A total of 190 events (177 relapses and 13 deaths without relapse) were reported, and the median follow up was 6.5 years (range, 2 to 10 years). The incidence rates of CNS relapse were similar in both arms whether isolated (5.6% and 3.3%, respectively) or combined (5.3% and 4.6%, respectively). The estimated 6-year disease-free survival (DFS) rate was similar (log-rank P =.67) in the two treatment groups: 70.4% (SE = 2.6%) in Arm A and 71.0% (SE = 2.5%) in Arm B. The 6-year DFS rate was similar for ALL and LL patients: 70.2% (SE = 1.9%) versus 76.3% (SE = 5.6%). CONCLUSION: Prevention of CNS relapse was satisfactorily achieved with HD IV MTX and intrathecal injections of MTX in children with increased-risk ALL or stage III and IV lymphoblastic lymphoma treated with our BFM-based treatment protocol in which cranial irradiation was omitted. Disappointingly, with the dose schedule used in this protocol, HD Ara-C added to HD MTX, although well tolerated, failed to further decrease the incidence of CNS relapse or to improve the overall DFS.

Actuarial Analysis↗
PubMed2001

[Neonatal screening for sickle cell anemia: evaluation of a five-year experience in an area of northern Paris].

UNLABELLED: We report a five-year experience of targeted neonatal screening for sickle cell disease in the northern part of the Paris area as well as the follow-up procedure of screened patients. POPULATION: This geographic area in France is characterized by a high frequency of populations at risk for sickle cell disease. RESULTS: Among 115,480 tested newborns, 250 patients were diagnosed (frequency: 1/462). The quality of the screening was attested by the high frequency (5.34%) of newborn carriers for a hemoglobin abnormality (n = 6168). We developed an optimized strategy which avoids the majority of pitfalls (false positive and false negative responses), except for S/HPFH. More than 95% of sickle cell disease was followed, the majority by medical sickle cell disease experts from hospitals. Only two deaths were recorded during this time period. CONCLUSION: We demonstrate the efficiency of targeting the proposed methodological strategy and the follow-up of affected newborns, a major argument demonstrating the importance of newborn screening.

Anemia, Sickle Cell↗
PubMed2001

Characterization of the B*5002-Cw*0602-DRB1*0406-DQB1*0402 Haplotype: impact on the unrelated-bone marrow donor search strategy.

Improvements in HLA-typing by DNA-based methods now allow accurate genotyping of unrelated bone marrow (UBM) donors and recipients and also definition of haplotypes. In this regard, B*5002 has been predicted in linkage disequilibrium with Cw*0602, DRB1*0406 and DQB1*0402 based on the frequency of allele coexistence. Here, we confirm this assumption by HLA genotyping of four informative families and three unrelated individuals. In the four families, the extended haplotype HLA-B*5002, -Cw*0602, -DRB1*0406, DQB1*0402 can be definitely assigned by the mode of heritance. Furthermore, this association of alleles was also found in the three B*5002 unrelated individuals. Knowledge of the frequent linkage disequilibrium of these rare alleles can improve UBM donor search strategies.

Bone Marrow Transplantation↗
PubMed2001

Early diagnosis of adenovirus infection and treatment with cidofovir after bone marrow transplantation in children.

Adenovirus infection remains an important cause of mortality after bone marrow transplantation (BMT). Currently no efficient antiviral treatment is known. Thus, testing new modalities of early diagnosis and treatment is a crucial objective. Adenovirus infection is defined by the combination of symptoms and the isolation of virus from the source of clinical symptoms. The involvement of two or more organs and the presence of virus in blood cultures define disseminated disease. Seven children with a median age of 7 years received bone marrow transplantation for leukemia. All received an unrelated graft without T cell depletion. Adenovirus was sought in blood, urine and biopsy specimens using PCR and culture. Analysis of biopsy specimens included systematic immunohistochemistry. Cidofovir treatment was initiated as soon as biopsy revealed the histopathological signs of adenovirus. Cidofovir was given at 5 mg/kg once weekly for 3 weeks then every 2 weeks. Six patients had diarrhoea and one patient had cystitis. Adenovirus infection and disseminated disease were diagnosed in four cases and three cases, respectively. In six cases, serotype A31 was isolated from gastrointestinal biopsy and in two cases serotypes B2 and C6 were detected in blood and urine. Cidofovir treatment was associated with clinical improvement of diarrhoea, cystitis and fever in five patients, in whom the virus became undetectable in cultures and PCR analyses despite the persistence of immunodeficiency. The median follow-up was 360 days after BMT (240-570). One child died of invasive aspergillosis and another of disseminated adenovirus after interruption of cidofovir therapy. Further studies in immunocompromised patients will be needed to extend these promising results concerning the role of cidofovir in adenovirus infection.

Adenovirus Infections, Human↗
PubMed2001

Deletion of chromosomal region 13q14.3 in childhood acute lymphoblastic leukemia.

Deletion of the 13q14 chromosomal region is frequent in B cell chronic lymphocytic leukemia (B-CLL) and is believed to inactivate a tumor supressor gene (TSG) next to RB1. We studied microsatellite markers spanning the 13q14 chromosomal region in 138 children with acute lymphoblastic leukemia (ALL). Allelic loss was demonstrated in six cases (4.3%). Deletion did not include RB1 in two cases. In five patients, the deleted region overlapped that described in B-CLL. A sixth patient harbored a smaller deletion, slightly more telomeric than minimal deleted regions reported in B-CLL. Apparent differences in the delineation of the minimal deleted region could be due to the fact that the putative TSG is a very large gene, with some deletions affecting only a part of it. Our present findings suggest that at least some of its exons lie within a region of less than 100 kb more telomeric that previously thought.

Adolescent↗
PubMed2001

Possible implication of thiopurine S-methyltransferase in occurrence of infectious episodes during maintenance therapy for childhood lymphoblastic leukemia with mercaptopurine.

6-Mercaptopurine (6-MP) is metabolized by thiopurine S-methyltransferase (TPMT), an enzyme subject to genetic polymorphism. We investigated the relationships between the TPMT locus (TPMT activity and genotype) and the pharmacological response to 6-MP during maintenance therapy of 78 children with acute lymphoblastic leukemia (ALL). For each patient, 6-MP dosage, leukocyte counts and occurrence of infectious episodes were monitored on an 8 week basis. Higher 6-MP dosage was associated with higher TPMT activity (P = 0.03) and higher average leukocyte counts (P < 0.01). Eight patients (10%) carrying a TPMT mutant genotype (one homozygous and seven heterozygous) received lower 6-MP doses (average: 48 vs 65 mg/m2/day; P = 0.02) and had on average lower leukocyte counts (2834 vs 3398 cells/mm3; P = 0.003) than patients carrying the wild-type TPMT genotype. Higher occurrence of infectious episodes graded 2 or 3 was correlated with higher 6-MP dosage (P < 0.01) but no difference was observed between TPMT mutants and TPMT wild-type patients. Patients who received 6-MP dosage above the group median (62 mg/m2/day) or having a TPMT activity above the group median (21.5 nmol/h/ml) had a higher percentage of 8 week periods with infectious episodes requiring treatment (34% vs 17% and 33% vs 19%, respectively) than those with 6-MP dose or TPMT activity below the group median (P < 0.01). In the last 25 patients enrolled in the study, steady-state erythrocyte thioguanine nucleotide (TGN) concentrations were associated with lower leukocyte counts (P= 0.01) but not with a higher occurrence of infectious episodes. In contrast, higher steady-state erythrocyte methylmercaptopurine nucleotide (MeMPN) concentrations were associated with higher 6-MP dosage (P< 0.01) and higher occurrence of infectious episodes (P < 0.001). In conclusion, during maintenance therapy of ALL, children with higher TPMT activity receive a higher 6-MP dosage and may have infectious episodes caused by metabolism of 6-MP into methylmercaptopurine nucleotides.

Adolescent↗
PubMed2001

Quantification of TEL-AML1 transcript for minimal residual disease assessment in childhood acute lymphoblastic leukaemia.

Strategies currently used for residual disease detection in acute lymphoblastic leukaemia (ALL) rely on polymerase chain reaction (PCR) detection of immunoglobulin and T-cell receptor rearrangements. The TEL-AML1 fusion transcript, which is associated with t(12;21) (p13;q22), is found in 25% of childhood B-cell precursor ALL, and represents an interesting alternative target. We compared two methods for quantitating TEL-AML1 fusion transcripts: competitive PCR and real-time PCR. These techniques showed similar sensitivity (5 x 10(-5)) and reproducibility. Giving highly correlated results, both techniques can be conveniently used for TEL-AML1 transcript quantification. The constancy of TEL-AML1 expression was evaluated by measuring TEL-AML1 transcripts at different steps of the cell cycle, and in 21 cases of ALL at diagnosis. No major variation in TEL-AML1 expression was observed during the cell cycle or in 20/21 of the ALL patients. Residual disease was then determined after completion of induction therapy in 20 patients with a TEL-AML1-positive ALL. Seven patients out of 20 (35%) were still positive, including two patients with high level of residual blasts (close to or beyond 10(-2)). When comparison was possible, results obtained using TEL-AML1 quantification were in accordance with those obtained using T-cell receptor rearrangements analysis.

Child↗
PubMed2001

Chimaeric anti-CD20 monoclonal antibody (rituximab) in post-transplant B-lymphoproliferative disorder following stem cell transplantation in children.

Post-transplant lymphoproliferative disorder (PTLD) after haemopoietic stem cell transplantation is a serious complication that occurs in 8-22% of patients with high-risk factors. We retrospectively investigated tolerance and efficacy of humanized anti-CD20 monoclonal antibody (rituximab) as first-line treatment in 12 children with B-cell PTLD. At diagnosis, eight patients had tumoral involvement. The other four patients had fever, associated with raised Epstein-Barr virus (EBV) viral load and monoclonal gammopathy. Rituximab was given at the dose of 375 mg/m2 once a week by intravenous infusion (1-9 infusions). Only 1/48 infusions was associated with a grade 2 clinical adverse event. Eight out of 12 (66%) patients responded to the treatment and were in complete remission. All patients without tumoral involvement responded to the treatment. A rapid decrease in fever within 1 week was observed in all responders. Non-responders did not show any clinical response during the first week. Tumoral involvement and immunodepression seemed to be more marked in non-responders. Rituximab was an effective and well-tolerated treatment of B-cell PTLD. Early treatment before tumoral involvement seemed to be the most effective approach. Lack of rapid response should lead to intensification of PTLD treatment. Pre-emptive treatment should be considered and evaluated in further longitudinal multicentre studies.

Antibodies, Monoclonal↗
PubMed2001

[T-cell-depleted HLA non-identical bone marrow transplantation in the child: prevention of graft-versus-host reaction by administration of donor T lymphocytes alloreactive against the recipient].

The success of HSCT from HLA partially disparate donors depends on the development of new strategies able to efficiently prevent GVHD and to protect patients from infections and relapse. Using an immunotoxin (IT) directed against the alpha-chain (p55) of the human IL-2r (RFT5-SMPT-dgA), we have previously shown that it is possible to kill mature T cells activated towards a specific HLA complex by a one-way MLR. We designed a clinical trial assessing the effect of infusing increasing doses of T lymphocytes in the setting of children recipients of non HLA genetically identical HSCT. Thirteen patients have been enrolled from September 1998 to April 2000 and fourteen HSCT have been realized in 13 patients (pts). Donors were MUD in 3 cases and familial HLA partially disparate in the remaining cases. Allodepleted donor T cells were injected between day +14 and day +30 provided that ATG was undetectable in the serum and blood PMN counts was > 500/microliter. The mean age of these patients was 17 months (range 1 to 42). Diagnosis included immune deficient and malignant hemopathies. Three patients received 1 x 10(5) allodepleted T cell/kg, 7 patients received 4 x 10(5)/kg and 4 patients received 6 x 10(5)/kg allodepleted T cells. Full inhibition of MLR was achieved in 12 out of 14 cases. In two cases, a residual T cell reactivity to the recipient was observed (4 to 5%) and patients developed grade II aGVHD. aGVHD occurred in 4 out of 11 grafted patients (all grade II). No chronic GVHD has developed, so far. Three patients died from severe VOD or PHT at day +34, day 51 and day +166, while one infected patient by VZV, CMV and EBV before HSCT died 6 months after transplantation from meningoencephalitis and another patient died from relapse at day +291. The patient for which there was no engraftment died at day +48 from staphylococcus infection. Overall survival is 54%, with a median follow up of 8 months; the mean time to reach a blood lymphocyte count > 500 was 41 days, to reach a CD3 count > 300 microliters 63 days (20-111), CD4 > 200 microliters 97 days and positive mitogen-induced proliferation 90 days. In three patients, a tetanus-toxoid positive proliferation was detected before immunization. From this intermediate analysis, we conclude that 1) specific allodepletion is an effective approach to prevent aGVHD in a haploincompatible setting, 2) data on immunological reconstitution suggest that infused T cells do survive and expand. A higher number of patients must be enrolled to determine the optimal number of T cells to infuse.

Acute Disease↗
PubMed2000

Clinical and metabolic presentation of the lipodystrophic syndrome in HIV-infected children.

OBJECTIVE: To investigate body fat distribution and glucose and lipid metabolism in HIV-infected children with the aim of describing the lipodystrophic syndrome in children. DESIGN: Cross-sectional study including 39 HIV-infected children aged 3-18 years. MAIN OUTCOME MEASURES: Clinical lipodystrophy was defined as peripheral fat wasting (facial and/or buttock and/or limb atrophy with arm skinfold thickness lower than the third percentile of the reference values for sex and age) and/or truncal adiposity (breast enlargement and/or buffalo neck and/or relative abdominal obesity with trunk : arm skinfold ratio > 2 standard deviations). Fasting serum lipid concentrations were measured and an oral glucose tolerance test was performed. RESULTS: Of 39 HIV-infected children, lipodystrophy was observed in 13 children (33.3%): eight with truncal lipohypertrophy, three with peripheral lipoatrophy and two with combined lipodystrophy. Combined lipodystrophies were observed only in adolescents with a more severe presentation than in prepubertal children. Lipodystrophic children had higher fasting insulinaemia (7.0+/-8.5 versus 3.0+/-2.3 microU/ml; P = 0.07), suggesting a certain degree of insulin-resistance. Hypercholesterolaemia (23% versus 15%; P = 0.59 ) and hypertriglyceridaemia (15% versus 11%; P = 0.76) were observed with the same proportion in the lipodystrophic as in the non-lipodystrophic groups; 23% of the non-lipodystrophic children had dyslipidaemia. CONCLUSION: The lipodystrophic syndrome prevails in HIV-infected children in the three clinical forms initially described in adults but appears less severe before the initiation of puberty. Insulin-resistance occurs in lipodystrophic children only, whereas dyslipidaemia exists in non-lipodystrophic children as well, suggesting that dyslipidaemia could reflect subclinical alteration of the adipose tissue.

Adolescent↗
PubMed2000

Protein truncation test of LYST reveals heterogenous mutations in patients with Chediak-Higashi syndrome.

Chediak-Higashi syndrome (CHS) is a rare autosomal recessive disorder in which an immune deficiency occurs in association with pigmentation abnormalities. Most patients who do not undergo bone marrow transplantation die of a lymphoproliferative syndrome, though some patients with CHS have a relatively milder clinical course of the disease. The large size of the LYST gene, defective in CHS, has made it difficult to screen for mutations in a large number of patients. Only 8 mutations have been identified so far, and all lead to a truncated LYST protein. We conducted protein truncation tests on this gene in 8 patients with CHS. Different LYST mutations were identified in all subjects through this approach, strengthening the observation of a high frequency of truncated LYST proteins as the genetic cause of CHS.

Adolescent↗
PubMed2000

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Journal Article↗
PubMed2000

[Development of care activities for children with sickle cell disease at the Robert-Debré Hospital (Paris), between 1992 and 1996].

AIM: In recent years, physicians at the Robert-Debré pediatric hospital in Paris perceived an increase in activity linked to sickle cell disease care. Our study had two objectives: first, to describe the evolution of care for children with sickle cell disease in the hospital, then, if a heavier intensity of care was shown, to try to investigate its causes. METHODS AND PATIENTS: We conducted a retrospective study using two strategies. On one hand, we compared the group of children followed up in 1992 with the group of children followed up in 1996 for their phenotype and hospitalizations (frequency, length of stay and type of complications), on the other hand, we described the course of complications and hospitalizations in the cohort of children followed from 1992 to 1996. Children were spotted through lists established by the 'Center for sickle cell disease', which coordinates the follow-up of all sickle cell patients in the hospital. Data came from the hospital's information system, and from all (medical, nursing, and social) individual records. RESULTS: The major result of this study shows an increasing activity linked to sickle cell disease care in this hospital: multiplication of hospitalizations and increasing work load for the healthcare teams. This situation is due to a larger recruitment, a higher emergency hospitalization rate, and an increasing rate of complications among the sickle cell children. The children's ageing is part of the explanation. The work load for the healthcare team linked to each hospitalization has also grown, as shown by an increasing rate of morphine prescription.

Anemia, Sickle Cell↗
PubMed2000

[Patient-controlled analgesia for prolonged pain in the child. An open-label feasibility study of a standardized method].

BACKGROUND: Patient-controlled analgesia (PCA) has been shown to be superior to a continuous morphine infusion for the treatment of ongoing pain in children over five years of age. Nevertheless, prescription parameters such as the bolus dosage and the possible association of a continuous background infusion have not yet been standardized. PATIENTS AND METHODS: Thirty-three children, aged four to 17, hospitalized in a pediatric hematology ward, benefited from PCA with a standardized prescription: a bolus dosage of at least 25 mg/kg, without a background infusion. Morphine consumption, side effects and efficacy on pain relief were followed. RESULTS: Median of mean morphine consumption was 0.32 mg.kg-1.d-1. Median of maximal consumption was 0.58 mg.kg-1.d-1. Mean duration was nine days. No important side effects were noted, except in two patients. They presented prolonged constipation and a poor quality of nocturnal sleep, but they also had a major depressive syndrome persisting after resolution of pain. Efficacy was comparable to a continuous intravenous infusion, and nocturnal sleep was of good quality for 31 children. CONCLUSION: This standardized technique of PCA can be used extensively in children over five years of age. It can be used as a reference for further studies.

Adolescent↗
PubMed2000

Long-term results of three randomized trials (58831, 58832, 58881) in childhood acute lymphoblastic leukemia: a CLCG-EORTC report. Children Leukemia Cooperative Group.

We present here the long-term results of three randomized clinical trials conducted on children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1983 and 1998 by the Children Leukemia Cooperative Group (CLCG) from EORTC. In study 58831/32, the overall event-free survival (EFS) rates (+/- s.e.) at 6 and 10 years were 66% +/- 1.8% and 65% +/- 1.8%, respectively, and the risk of isolated central nervous system (CNS) relapse was 6% +/- 1% and 7% +/- 1%, respectively. In patients with a standard risk of relapse the omission of cyclophosphamide had no adverse effect on disease-free survival rates at 10 years (trial 58831). In medium- and high-risk patients the omission of radiotherapy did not increase the risk of CNS or systemic relapse (trial 58832). In study 58881 (1989-1998) the overall EFS rate at 8 years was 68.4% +/- 1.2% and the risk of isolated CNS relapse was 4.2%+/-0.5%. In this trial which adressed three randomized questions, the following results were obtained: the combination of cytarabine at high doses with methotrexate at high doses during interval therapy did not improve prognosis. The addition of 6-mercaptopurine iv during maintenance increased the risk of late relapse. E. coli asparaginase was more toxic and has a higher efficacy than Erwinia asparaginase. Leukocyte counts >100 x 10(9)/l, specific genetic abnormalities, a poor initial response to steroids or a high level of minimal residual disease at early time points were consistently associated with an adverse prognosis in the 58881 trial.

Antineoplastic Combined Chemotherapy Protocols↗