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Biomedical subjects

G Souillet

Publications and source records attributed to G Souillet.

At least 73 records · Page 4Linked to original sources
PubMed1993

Busulfan disposition below the age of three: alteration in children with lysosomal storage disease.

Busulfan disposition is age-dependent with a higher clearance and a larger volume of distribution in children than in adults. The optimal dosage of busulfan needed to achieve bone marrow (BM) displacement in young children with malignant or nonmalignant disease remains to be defined. Using a gas chromatography-mass spectrometry assay, we evaluated plasma pharmacokinetics of busulfan in 33 children (median age, 9 months; range, 2 months to 2.75 years) with immune deficiencies, lysosomal storage diseases, acute leukemias, and malignant lymphohistiocytosis after an oral dose ranging from 0.9 to 2.6 mg/kg. The busulfan clearance (assuming a bioavailability of 1) ranged from 2.1 to 13.4 mL/min/kg with a mean of 6.8 mL/min/kg, which is higher than that reported in older children (4.5 mL/min/kg) and adults (2.9 mL/min/kg). Six children with lysosomal storage disease (5 with Hurler's disease, 1 with San Filippo's disease) had a prolonged elimination half-life (4.9 v 2.4 hours), a larger volume of distribution (3.4 v 1.2 L/kg) and a faster clearance (8.7 v 6.3 mL/min/kg) than the other 27 children. This suggests that a higher dose of busulfan will be required to achieve BM displacement in children with lysosomal storage disease. Over the dose range of 0.9 to 2.6 mg/kg, busulfan pharmacokinetics were linear. However, only 46% of the interpatient variation in systemic exposure could be ascribed to the dose. Given the wide interpatient variability in busulfan disposition, dose adjustment and drug monitoring will be needed to achieve the optimal dosage of busulfan in young children. The plasma busulfan levels required to achieve BM displacement need to be defined, especially in lysosomal storage diseases.

Age Factors↗
PubMed1993

[Langerhans cell histiocytosis associated with myasthenia in an infant].

The pathogenesis of Langerhans cell histiocytosis (LCH) is unclear, but there is increasing evidence that an immunological dysfunction is present. We describe an infant who presented a LCH associated with myasthenia gravis. The thymus is known to play an important role in the pathophysiology of myasthenia gravis and is often involved in LCH. Infancy and signs of organ dysfunction are predictive of poor prognosis: immunotherapy is to be investigated (thymic hormone, cyclosporin, alpha interferon), as well as allogeneic bone marrow transplantation.

Female↗
PubMed1993

[Treatment of severe forms of sickle cell anemia with bone marrow allograft: French experience (15 cases). SFGM].

Fifteen S/S children with severe SCD were transplanted with marrow from HLA identical siblings. All developed frequent (> 3/y) vaso-occlusive crises (VOC) associated with recurrent acute chest syndrome episodes (n = 10), osteitis (n = 3), osteonecrosis (n = 3), strokes (n = 3) or frequent massive deglobulisation (n = 2). Two children undergone splenectomy, two were chelated and two had an erythroid allo-immunization. Ethnic origins were from various countries in Africa (n = 11), North-Africa (n = 3) or West Indies (n = 1). At BMT, they were 2y 3m to 14y 9m old (mean: 8y 7m). Donors were AS (n = 11) or AA (n = 4). At first, various conditioning regimens were used consisting of busulfan (BU) plus Cyclophosphamide (CY) at different doses: CY:200 mg/kg (n = 13) or 260 mg/kg (n = 2); BU: 14 mg/kg (n = 1), 16 mg/kg (n = 9), > 16 mg/kg (n = 5); one patient received also TLI and the last two anti-thymoglobulin (ATG): 20 mg/kg. GVHD prophylaxis was CSA alone (n = 4) or CSA plus short-term MTX (n = 11). Median follow-up is 28 months (5 m to 53 m). All patients had an engraftment (d12 to d32) with a stable total chimerism in 10/14 patients. In the 4 others, partial chimerism was observed: one patient had a early and progressive rejection of his graft but is doing very well (35 m follow-up) without any manifestation of SCD, with a high stable 22% Hb F level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Bone marrow transplantation (BMT) in 14 children with severe sickle cell disease (SCD): the French experience. GEGMO.

Fourteen S/S children with severe SCD were transplanted with marrow from HLA identical siblings. All developed frequent (> 4/y) vasoocclusive crises (VOC) and recurrent acute chest syndrome episodes (n:10), osteitis (n:3), osteonecrosis (n:3), strokes (n:3) or frequent massive deglobulisation (n:2). Two children undergone splenectomy, 2 were chelated and 2 had erythroid allo-immunization. Ethnic origins were from various countries in Africa (n:10), North-Africa (n:3) or West Indies (n:1). At BMT, they were 2y 3m to 14y 9m old (mean:8y 7m). Donors were AS (n:11) or AA (n:3). At first, various conditioning regimens were used consisting of busulfan (BU) plus Cyclophosphamide (CY) at different doses: CY:200 mg/kg (n:12) or 260 mg/kg (n:2); BU:14 mg/kg (n:1), 16 mg/kg (n:9), > 16 mg/kg (n:4); 1 patient received also TLI and one other antithymoglobulin (ATG): 20 mg/kg. GVHD prophylaxis was CSA alone (n:4) or CSA plus short-term MTX (n:10). Median follow-up was 23 months (8 m. to 48 m.). All patients had an engraftment (d13 to d32) with a stable total chimerism in 10/14 patients who are cured. In the 4 others, partial chimerism was observed: one patient had a early and progressive rejection of his graft but is doing very well (28 m. follow-up) without any manifestation of SCD, with a high stable 22% Hb F level. One patient developed an aplastic anaemia 15 m after BMT: a second BMT was achieved 21 m after the first one with engraftment and total chimerism. Two patients have a relatively stable partial chimerism with still undergoing CSA therapy (11 m. and 23 m. follow-up).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Psychological aspects of bone marrow donation in donor brothers and sisters in bone marrow transplantation].

It appears to be necessary to consider, during a bone marrow transplantation, brothers and sisters who are donors. These children face psychological difficulties, which are not always understood by medical staff and families who are mainly concerned with the health of the sick children. Systematic meetings with a hundred donors point out the distress experienced in these situations.

Bone Marrow Transplantation↗
PubMed1993

Use of an anti-interleukin-2 receptor monoclonal antibody for GVHD prophylaxis in unrelated donor BMT.

Severe acute GVHD remains the main complication in unrelated donor BMT (UD-BMT). The previous encouraging reports on the use of anti-IL-2 receptor monoclonal Ab (33B31) for GVHD prophylaxis in genoidentical BMT led us to add this Ab to the standard GVHD prophylaxis regimen (MTX plus CsA). Sixty-four consecutive patients received 33B31, 20 mg on days 1 and 2, then 10 mg per day from day 3 to day 28 in association with CsA and MTX. They were compared with a historical control group of 89 patients who received conventional GVHD prophylaxis. The 33B31 was well tolerated. We did not find any statistical difference in terms of incidence and time of onset of severe GVHD, occurrence of chronic GVHD, engraftment, relapse or survival among the two groups. Immunization occurred but did not influence serum levels of 33B31. No correlation was found between the severity of GVHD and serum Ab levels. We conclude that other approaches for reducing acute GVHD should be developed to improve UD-BMT results.

Actuarial Analysis↗
PubMed1992

[Results and complications of induction treatment of acute leukemia in children. A personal series of 79 cases (1988-1989)].

In 1988 and 1989, 79 children have been treated for induction of acute leukemia. 68 presented an acute lymphoblastic leukemia (ALL) and 11 an acute non-lymphoblastic leukemia (ANLL). The complete remission rate was 92% (96% in ALL, 73% in ANLL). Fever occurred in 50% of the children, with positive blood cultures in 11 of them. One child died from streptococcal sepsis. No metabolic disorder was noted. Four patients were transferred into the intensive care unit. After 8 days, the treatment of ALL was continued in the outpatient clinic in more than 50% of the cases. The treatment of ANLL is frequently complicated by hemorrhages and sepsis and needs adapted supportive care in a specialized unit.

Adolescent↗
PubMed1992

The bare lymphocyte syndrome.

The bare lymphocyte syndrome is a combined immunodeficiency resulting from the lack of expression of either class I or class II HLA antigens at the cell surface. The main clinical manifestations are infections of the respiratory or the digestive tract. The immunodeficiency involves the absence of antibody formation and the absence of cell-mediated response, to specific antigen, contrasting with virtually normal transplant immunity to allogeneic determinants. The responsible gene(s) is not born by chromosome 6. The best treatment appears, at the present time, to be in utero stem cell transplantation into the sick fetus, and it may, in the future, be gene therapy.

Child, Preschool↗
PubMed1991

Shifts in interleukin-4 and interferon-gamma production by T cells of patients with elevated serum IgE levels and the modulatory effects of these lymphokines on spontaneous IgE synthesis.

Interleukin-4 (IL-4) has been demonstrated to induce IgE synthesis by peripheral blood mononuclear cells (PBMNCs) of healthy donors. In this study, we demonstrated that IL-4 also can enhance spontaneous IgE synthesis by PBMNCs of allergic/atopic patients and patients with Buckley's or hyper-IgE syndrome. Spontaneous IgE production by PBMNCs of these patients was suppressed by interferon (IFN)gamma or IFN-alpha in a dose-dependent fashion. Despite high serum IgE levels, no IL-4 could be detected in the serum of the patients, but indirect evidence was obtained indicating that enhanced IL-4 production in vivo may be associated with the high serum-IgE levels in these patients. Spontaneous IL-4 production was measured in PBMNC cultures of 4/21 patients tested. Furthermore, spontaneous IgE synthesis by PBMNCs of three other patients of seven tested in vitro was partly blocked by anti-IL-4 antiserum. In addition, levels of soluble CD23 (which is specifically induced by IL-4) were strongly elevated in sera of patients. Finally, activation of PBMNCs of the patients resulted in levels of IL-4 and of IFN-gamma synthesis that were higher and lower, respectively, than levels produced by PBMNCs of healthy control donors tested in parallel. Collectively, our data indicate that spontaneous IgE synthesis in vitro can be modulated by IL-4, IL-5, IFN-gamma, and IFN-alpha. In addition, our data suggest that enhanced IL-4 and reduced IFN-gamma production is associated with the elevated serum IgE levels observed in these patients.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1991

Improved survival at 2 and 5 years in the LMCE1 unselected group of 72 children with stage IV neuroblastoma older than 1 year of age at diagnosis: is cure possible in a small subgroup?

The objectives of this study were to determine (1) the role of selection before bone marrow transplantation (BMT), (2) the role of vincristine, melphalan, and total body irradiation (TBI) as consolidation of induction therapy for stage IV over 12 months at diagnosis, and (3) the role of immunomagnetic purging in metastatic neuroblastoma. Among 72 consecutive unselected patients, 10 were not grafted (four died at induction: two in complete remission [CR], two in partial remission [PR]); three had bone marrow progression before harvest; one had uncontrolled progression; and two had parental refusal). Sixty-two patients were grafted (23 in CR/very good PR [VGPR] and 39 in PR). Among the 62, 33 were consolidated with at least 90% excision of their initial tumor excised (53.2%), 15 with catecholamine secretions (24.2%), 22 with minor bone marrow involvement (35.5%), and 31 with positive bone scan (50%). Median observation time is 59 months. Progression-free survival (PFS) for the 10 excluded patients was 20% at 2 years and 0% at 4 years. PFS for the grafted population (n = 62) is 40% at 2 years, 20% at 4 years, and 13% at 7 years. No difference was observed between patients grafted in CR/VGPR or in PR. However, a group of 19 children was grafted resulting in complete normalization of metastasis (regardless of primary-site tumor status). In this group, PFS at 59 months was 38% with no relapses up to 7 years post-BMT. A group of 31 patients with no bone involvement at BMT was also identified. PFS at 5 years is 30% compared with 12% for bone-positive patients at BMT. Moreover, the 11 children presenting at diagnosis with no bone involvement (Evans stage IVS or stage C Memphis) and consolidated with BMT had PFS at 5 years of 50% with no late relapses. A subgroup of stage IV neuroblastoma patients older than 1 year of age at diagnosis may be curable with this therapeutic approach, and the use of multivariate analyses to search for prognostic factors is warranted in currently existing international registries.

Age Factors↗
PubMed1991

The TAM regimen prior to allogeneic and autologous bone marrow transplantation for high-risk acute lymphoblastic leukemias: a cooperative study of 62 patients.

A total of 62 patients with high-risk acute lymphoblastic leukemia (ALL) were treated with fractionated total body irradiation, high-dose cytosine arabinoside and melphalan followed by bone marrow transplantation (BMT). Thirty-six patients received allogeneic and 26 autologous BMT. Eight patients were treated in CR1, 36 in CR2 (first relapse occurring on therapy for 32), seven in further CR, 10 in relapse (five early first relapse, four second relapse and one fourth relapse) and one with refractory ALL. Severe toxicity occurred in 26 of the 62 patients (42%) and 14 died (22.5%) from non-leukemic causes. The actuarial event-free survival at 3.6 years was 28% after autologous BMT and 52% after allogeneic BMT with actuarial relapse rates of 62% and 35%, respectively. The results of this pilot study seem promising for this group of poor risk ALL, but the relapse rate remains high after autologous BMT and needs to be improved.

Adolescent↗