WorldCat Identities

Dumas, Pierre-Yves (1981-....; Auteur d'une thèse d'exercice en Médecine)

Works: 2 works in 3 publications in 1 language and 4 library holdings
Roles: Opponent, Other, Author
Publication Timeline
Most widely held works by Pierre-Yves Dumas
Epstein Barr virus et allogreffe de cellules souches hématopoïétiques : incidence et facteurs de risque dans les greffes de sang de cordon placentaire by Pierre-Yves Dumas( )

1 edition published in 2011 in French and held by 2 WorldCat member libraries worldwide

Epstein Barr Virus (EBV) viremia and post transplantation lymphoptoliferative disorders (PTLD) are usually associated with risk factors that lead ultimately to an impaired adaptative T cell mediated immunity. We performed a retrospective study in 175 patients transplanted with unrelated cord blood (UCB) for hematologic malignancies and aplastic anemia with the aim to analyze the incidence and risk factors for EBV reactivation. Patients received the UCB transplantation at the University of Bordeaux, Lyon and Clermont-Ferrand Hospital and Saint-Louis Hospital, between October 2003 and December 2009. Real-time quantitative polymerase chain reaction was used to monitore, at least once a week during the first three months, the EBV load. The median age was 23 years, 74.2 % had acute leukemia or myeloid malignancies. Grafts have been performed with double UCB in 44 %. The median number of nucleated cells infused in recipients of UCB was 3.1 x 10^7/kg of the recipient's body (range 1 x 107 to 17.8 x 10^7/kg. The median number of CD34 cells was 1.7 x 10^5/kg (range 0.13 x 10^5 to 22.4 x 10^5/kg). Conditioning varied with 54 % myeloablative and 46 % reduced intensity (RIC). All patients, except 2, received a cyclosporine A containing prophylaxis for GVHD, associated with MMF in 50.3 %, and prednisone in 30.2 patients. Grafts were 4 to 6/6 HLA matched to the recipient except for 15 patients with < or = 3 of 6 HLA matched grafts. Individuals were EBV seropositive prior to allograft in 88 %. At 100 days the cumulative incidence for EBV related complications was about 8 ± 2 % with 4 EBV diseases. The median time to development of EBV event was 83 days (range 14 days-2.7 years. In univariate analysis, the increased risk is mainly associated with RIC + ATG (p = 0.03) and previous history of autologous HSCT (p = 0.01). Multivariate analysis did not find any independant risk factor for EBV reactivation, but RIC + ATG conditioning seems increasingly to emerge in studies
Atteintes médullaires et extramédullaires des leucémies aigues myéloïdes : rôle de CD36 by Thomas Farge( Book )

2 editions published in 2021 in French and held by 2 WorldCat member libraries worldwide

Acute myeloid leukemia (AML) is a malignant disease of hematopoietic stem and progenitor cells with an annual incidence of 4/100,000. AML is characterized by the accumulation of immature blast cells in the bone marrow and blood. Induction chemotherapy leads to a complete remission of patients in 90% of cases. Despite this high rate, the prognosis remains poor due to resistance to chemotherapy, which leads to relapse. Previously, we have shown in preclinical in vivo models (xenografts of patient cells or cells lines) that AML cells that are resistant to chemotherapy display a high oxidative mitochondrial metabolism that contributes to chemoresistance. Transcriptomic analyses and flow cytometry experiments shown that CD36, a membrane protein with multiple functions, was enriched in chemoresistant cells. The aim of my thesis was to characterize the role of CD36 in medullary and extramedullary disease progression, and in the response of leukemic blasts to chemotherapeutic treatment. One of the well described functions of CD36 is its ability to transport lipids. We therefore hypothesized that this function could support fatty acid oxidation and mitochondrial metabolism, but our experiments showed that this function is minor in leukemic blasts. In solid cancers, CD36 fosters cell migration and metastatic spread. As an extramedullary disease is present in about a quarter of AML patients, we hypothesized that CD36 might contribute to the dissemination of leukemic blasts, and that extramedullary disease is comparable to a chemotherapy-resistant metastatic state. Using shRNA invalidation and blocking antibodies in cell lines and primary patient cells, we showed that CD36 increases leukemic cell migration toward different types of stroma cells in vitro. In vivo, CD36 increases the localization of leukemic blasts in various extramedullary tissues, in particular in adipose tissues, liver and lung. In three different preclinical models, we have shown that the inhibition of CD36 increases the life span of chemotherapy-treated mice. In humans, CD36 protein expression is positively correlated with extramedullary localization of blasts, and with a reduced survival in patients of the Toulouse University Cancer Institute cohort. This work allowed us to propose a new role for CD36 in the extramedullary localization of blasts and in the progression of the disease after chemotherapy. The research core on AML is focused on leukemic cells present in the bone marrow. Considering AML as a metastatic disease in which extramedullary niches are involved in disease's development and treatment resistance could provide a more holistic view of AML, opening new therapeutic strategies through CD36 inhibition and targeting of extramedullary disease
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French (3)