Biomedical subjects
Sophie de Guibert
Publications and source records attributed to Sophie de Guibert.
Soluble HLA-G molecules increase during acute leukemia, especially in subtypes affecting monocytic and lymphoid lineages.
Human leukocyte antigen G (HLA-G) molecules exhibit immunomodulatory properties corresponding to nonclassic class I genes of the major histocompatibility complex. They are either membrane-bound or solubly expressed during certain tumoral malignancies. Soluble human leukocyte antigen G (sHLA-G) molecules seem more frequently expressed than membrane-bound isoforms during hematologic malignancies, such as lymphoproliferative disorders. Assay of these molecules by enzyme-linked immunosorbent assay in patients suffering from another hematologic disorder (acute leukemia) highlights increased sHLA-G secretion. This increased secretion seems more marked in acute leukemia subtypes affecting monocytic and lymphoid lineages such as FABM4 and FABM5, as well as both B and T acute lymphoblastic leukemia (ALL). Moreover, this study uses in vitro cytokine stimulations and reveals the respective potential roles of granulocyte-macrophage colony-stimulating factor and interferon-gamma in increasing this secretion in FABM4 and ALL. Correlations between sHLA-G plasma level and clinical biologic features suggest a link between elevated sHLA-G level and 1) the absence of anterior myelodysplasia and 2) high-level leukocytosis. All these findings suggest that sHLA-G molecules could be a factor in tumoral escape from immune survey during acute leukemia.
Rituximab and DHAP followed by intensive therapy with autologous stem-cell transplantation as first-line therapy for mantle cell lymphoma.
We report on a series of 24 patients with newly diagnosed mantle cell lymphoma treated with four to six courses of DHAP-rituximab followed by autologous stem cell transplantation for patients <65 years. Three-year overall survival (OS) and event free survival (EFS) rates were 69% and 65% respectively, for the 24 patients. In intent-to-treat analysis, 3-year OS and EFS were 75% and 76% for the 17 patients < 65 years old. This treatment is quite feasible and compares favourably with other regimens.
New drugs for colorectal cancer (irinotecan, oxaliplatin, raltitrexed) meet expectations in routine practice: a single center's experience before and after their introduction.
BACKGROUND AND AIMS: Treatment of metastatic colorectal cancer with new drugs (NDs) as oxaliplatin and irinotecan had improved response and survival. In order to check whether the promising achievements of the trials are obtained in routine clinical practice, we have reviewed retrospectively our results for two periods, before (period A: 1993-1995, n=63) and after (period B:1998-2000 n=103) the introduction of these NDs. Patients characteristics, treatment modalities, survival, and prognostic factors were compared. PATIENTS: There were 74 women and 92 men, aged 60.8+/-11.6 yr, 7 patients received best supportive care only, 91 had synchronous metastasis. RESULTS: Period B patients were older, with WHO score>1 more often, more adjuvant treatment, more metachronous metastasis, and NDs used more frequently (24% vs 59%). Median survival was similar (16 vs 15 mo). But when looking at the population aged<75 years with WHO score<2, median survival was 13 mo (period A) vs 21 mo (period B); survival at 1, 2, and 3 yr were respectively 59.5+/-8%, 16.2+/-6 %, 13.5+/-6 % vs 69.8+/-6%, 49.6+/-7%, 29.8+/-7%, p<0.01). In multiparametric analysis, factors correlated with survival were the absence of elevated serum alkaline phosphatase, a unique metastatic organ, and administration of NDs. CONCLUSION: In our routine clinical experience the use of NDs for metastatic CRC has allowed a significant improvement in survival among patients with unresectable tumors.
Suppressive properties of human CD4+CD25+ regulatory T cells are dependent on CTLA-4 expression.
It has been demonstrated that T cells with regulatory properties are present within the peripheral blood CD4(+)CD25(+) T cell compartment. Here, we describe an original method to purify human CD4(+)CD25(+)CD152(+) T lymphocytes as living cells by forcing the exportation of CTLA-4 molecules stored in intracellular vesicules at the cell surface. By doing so, we demonstrate that CD4(+)CD25(+) T cells contain a smaller and more homogeneous population enriched in cells with in vitro regulatory activity. Moreover, we show that this enrichment in regulatory T cells is associated with an increased expression of Foxp3 and that CD4(+)CD25(+)CD152(+) T lymphocytes display a much stronger suppressive activity in controlling in vitro proliferation of alloantigen-specific T cells than CD4(+)CD25(+)CD152(-) T lymphocytes purified in parallel. Lastly, by purifying such cells expressing CTLA-4, we demonstrate that indeed CTLA-4 is involved in CD4(+)CD25(+)CD152(+) T cell regulatory activity, while suppressive cytokines are not.