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Yves Beguin

Publications and source records attributed to Yves Beguin.

At least 19 recordsLinked to original sources
PubMed2006

Despite inhibition of hematopoietic progenitor cell growth in vitro, the tyrosine kinase inhibitor imatinib does not impair engraftment of human CD133+ cells into NOD/SCIDbeta2mNull mice.

There is potential interest for combining allogeneic hematopoietic cell transplantation (HCT), and particularly allogeneic HCT with a nonmyeloablative regimen, to the tyrosine kinase inhibitor imatinib (Glivec; Novartis, Basel, Switzerland, http://www.novartis.com) in order to maximize anti-leukemic activity against Philadelphia chromosome-positive leukemias. However, because imatinib inhibits c-kit, the stem cell factor receptor, it could interfere with bone marrow engraftment. In this study, we examined the impact of imatinib on normal progenitor cell function. Imatinib decreased the colony-forming capacity of mobilized peripheral blood human CD133(+) cells but not that of long-term culture-initiating cells. Imatinib also decreased the proliferation of cytokine-stimulated CD133(+) cells but did not induce apoptosis of these cells. Expression of very late antigen (VLA)-4, VLA-5, and CXCR4 of CD133(+) cells was not modified by imatinib, but imatinib decreased the ability of CD133(+) cells to migrate. Finally, imatinib did not decrease engraftment of CD133(+) cells into irradiated nonobese diabetic/severe combined immunodeficient/beta2m(null) mice conditioned with 3 or 1 Gy total body irradiation. In summary, our results suggest that, despite inhibition of hematopoietic progenitor cell growth in vitro, imatinib does not interfere with hematopoietic stem cell engraftment.

AC133 Antigen↗
PubMed2006

Role of stromal-derived factor-1 in the hematopoietic-supporting activity of human mesenchymal stem cells.

Mesenchymal stem cells (MSC) have the ability to support and maintain hematopoiesis in vitro. However, mechanisms implicated in this support are not fully characterized. In the present study, the role of stromal-derived factor-1 (SDF-1)/CXCR4 axis in the interactions between MSC and hematopoietic stem/progenitor cells (HSPC) was studied. Human bone marrow MSC were plated as feeder layers in Dexter-type long-term cultures (LTC) with human cord blood CD34(+) HSPC. Cultures were supplemented weekly with neutralizing antibodies against CXCR4 or SDF-1 for 5 wk. LTC-initiating cell (IC) activity was strongly dependent on the SDF-1/CXCR4 axis, as both antibodies significantly decreased secondary colony-forming cell production. To assess the effect of SDF-1/CXCR4 axis on progenitor cell proliferation, LTC-IC killing assays were carried out: in LTC of CD34(+) cells in contact with MSC, treatment with anti-CXCR4 antibody significantly reduced the number of cycling progenitors. These results indicate that the SDF-1/CXCR4 axis promotes HSPC proliferation in contact with MSC. Interestingly, when HSPC were separated from MSC by a semipermeable membrane, LTC-IC activity became CXCR4 independent. Multiplex analysis of MSC-conditioned medium revealed that in addition to SDF-1, MSC produced stimulatory and inhibitory factors, such as interleukin (IL)-6, IL-11, granulocyte macrophage-colony stimulating factor as well as monocyte-chemoattractant protein-1. Altogether, human MSC support hematopoiesis in Dexter-type cultures through the activation of the SDF-1/CXCR4 axis. Our data further suggest that SDF-1 stimulates retention of HSPC in MSC niches which expose them to stimulatory and inhibitory factors in a paracrine manner.

Antibodies↗
PubMed2006

Pegfilgrastim compared with Filgrastim after autologous hematopoietic peripheral blood stem cell transplantation.

In order to assess the effect of Pegfilgrastim on the duration of neutropenia and clinical outcome of patients after autologous peripheral blood stem cell (PBSC) transplantation, we compared 20 consecutive patients with lymphoma or multiple myeloma receiving a single 6-mg dose of Pegfilgrastim on day 1 posttransplant to an historical control group of 60 patients receiving daily Filgrastim 5 microg/kg starting on day 1 posttransplant. The duration of neutropenia was similar in the Pegfilgrastim group compared with the control group. There were no differences in time to neutrophil, erythroid, or platelet engraftment nor in the incidence of fever and infections. The duration of antibiotic therapy, transfusion support, and time to hospital discharge were similar in the two groups. However, after initial hematopoietic reconstitution, we observed significantly higher values of lymphocytes (e.g., 1,660+/-1,000 versus 970+/-460 on day 80, p=0.0002), neutrophils (e.g., 3,880+/-2,030 versus 2,420+/-1,500 on day 25, p=0.0004), reticulocytes (e.g., 148,160+/-90,590 versus 87,140+/-65,920 on day 25, p<0.0001), and platelets (e.g., 210,700+/-116,090 versus 150,240+/-58,230 on day 55, p=0.0052) up to day 100 in the Pegfilgrastim group compared with the Filgrastim group. These observations had no impact on clinical outcome of the patients after day 30 due to the low incidence of infectious events after engraftment in autologous PBSC transplantation. We conclude that the effect of Pegfilgrastim administrated on day 1 posttransplant is comparable to that of daily Filgrastim on initial hematopoietic reconstitution. The possibly superior effect of Pegfilgrastim on cell counts we observed after initial engraftment should be further tested in a prospective randomized trial.

Antineoplastic Agents↗
PubMed2006

Recombinant human erythropoietin therapy after allogeneic hematopoietic cell transplantation with a nonmyeloablative conditioning regimen: low donor chimerism predicts for poor response.

PURPOSE: After allogeneic hematopoietic stem cell transplantation with nonmyeloablative conditioning (NMHCT), many patients experience prolonged anemia and require red blood cell (RBC) transfusions. We enrolled 60 consecutive patients undergoing NMHCT in a phase II trial to determine the optimal utilization of recombinant human erythropoietin (rHuEPO) therapy in this setting. PATIENTS AND METHODS: The first 14 NMHCT recipients did not receive rHuEPO (control group). Nineteen patients were scheduled to start rHuEPO on day 0 (EPO group 2) and 27 patients on day 28 after the transplant (EPO group 1). RHuEPO was administered subcutaneously once weekly at a dose of 500 U/kg/wk with the aim of achieving hemoglobin (Hb) levels of 13 g/dL. The 3 groups were well balanced for major characteristics. RESULTS: During the first month (p < 0.0001) as well as days 30 to 100 (p < 0.0001) and days 100 to 180 (p < 0.0001), Hb values were higher in patients receiving rHuEPO compared to those not receiving it. However, transfusion requirements were significantly decreased only in the first month in EPO group 2 (p = 0.0169). T-cell chimerism above 60% on day 42 was the best predictor of Hb response (p < 0.0001) or Hb correction (p = 0.0217), but myeloid chimerism above 90% also predicted for Hb response (p = 0.0069). Hb response was also decreased in patients receiving CD8-depleted grafts and increased in the few patients not receiving TBI, but only in univariate analysis. CONCLUSIONS: Anemia after NMHCT is sensitive to rHuEPO therapy, but less so than after conventional allogeneic HCT. RHuEPO decreases transfusion requirements only in the first 30 days posttransplant. T-cell chimerism below 60% on day 42 impaired Hb response, suggesting possible inhibition of donor erythropoiesis by residual recipient lymphocytes. A prospective randomized trial should be performed with rHuEPO starting on the day of transplantation to assess its clinical benefit in terms of transfusion requirements and quality of life.

Adult↗
PubMed2006

Increased iron absorption during autologous blood donation supported by recombinant human erythropoietin therapy.

BACKGROUND: Recombinant human erythropoietin (rHuEPO) therapy improves the success of autologous blood (AB) donation programs before elective surgery. The aim of this study was to evaluate iron absorption during an AB donation program with or without rHuEPO. STUDY DESIGN AND METHODS: Thirty-two patients were randomly assigned among placebo (Group 1) or 300 (Group 2) or 600 UI per kg rHuEPO (Group 3) on the first, second, and third donation visits. All patients also received daily oral iron (200 mg Fe(+)). RESULTS: The number of units collected in Group 3 was higher than in Group 1 (4.6 +/- 0.5 vs. 3.6 +/- 0.8 units; p < 0.01). Red blood cell (RBC) production increased in a rHuEPO dose-dependent manner. With rHuEPO, the RBC volume collected per unit presented a lower decrease with number of donated units than with placebo and was similar to that of homologous blood units. Storage iron did not influence the number of units collected, whereas circulating mobilizable iron was the limiting factor. Oral iron absorption increased in a rHuEPO dose-dependent manner (12-fold with 600 UI/kg rHuEPO) and was proportional to erythropoietic activity. CONCLUSION: rHuEPO does not only improve the number of AB units collected but also their quality. Storage iron cannot meet marrow iron requirements, but rHuEPO strongly increased oral iron absorption in a dose-dependent fashion through stimulation of erythropoietic activity.

Adult↗
PubMed2006

Infections after CD34-selected or unmanipulated autologous hematopoietic stem cell transplantation.

Immune reconstitution may be delayed after CD34-selected compared with unmanipulated autologous peripheral blood stem cell transplantation (PBSCT), resulting in a theoretically increased risk of infections. In a case-control matched study we compared the incidence of infection in 25 recipients of CD34-selected PBSC (CD34 group) and 75 recipients of unmanipulated PBSC (PBSC group) transplants. The population included 52 males and 48 females suffering from non-Hodgkin's lymphoma (n = 32), Hodgkin's disease (n = 8), multiple myeloma (n = 40) or breast cancer (n = 20). Neutrophil engraftment was comparable in the two groups. The actuarial incidence of infection was similar in the two groups (56% vs. 49% at day 30, and 70% vs. 64% at 1 yr respectively). The proportion of patients with 1, 2 or 3 infections, the number of infectious event per patient (1.32 vs. 1.04; NS), the number of infections before day 15 or 30, between days 31 and 100 or after day 100, the risk of varicella-zoster virus or cytomegalovirus infection or disease, or the use of antibiotic or antifungal therapy, were not increased in the CD34 compared with the PBSC group. The main agents responsible for infection were bacteria, particularly gram-positive cocci, in both groups. Bacteremia accounted for 33% of all infectious events in the CD34 group vs. 16% in the PBSC group (P < 0.05). Fungal infections were rare. In conclusion, our results do not support the notion that CD34-selection of the graft is associated with an increased rate of infection after autologous PBSC transplantation. The role of extended infection prophylaxis should be evaluated.

Adult↗
PubMed2006

Iron and the anaemia of chronic disease: a review and strategic recommendations.

BACKGROUND: The incidence of anaemia is high in many chronic conditions, yet it often receives little attention. SCOPE/METHODS: A panel of international experts with experience in haematology, nephrology, oncology, rheumatology and pharmacy was convened to prepare strategic guidelines. A focused literature search was conducted after key issues had been identified. A series of recommendations was agreed, backed, wherever possible, by published evidence which is included in the annotations. RECOMMENDATIONS: Anaemia is a critical issue for patients with chronic diseases. Healthcare professionals need to recognise that anaemia is a frequent companion of cancer and chronic conditions such as rheumatoid arthritis and heart failure. It reduces patients' quality of life and can increase morbidity and mortality. Anaemia should be considered as a disordered process in which the rate of red cell production fails to match the rate of destruction which leads eventually to a reduction in haemoglobin concentration; this process is common to all chronic anaemias. The aim of anaemia management should be to restore patient functionality and quality of life by restoring effective red cell production. Blood transfusion can elevate haemoglobin concentration in the short term but does nothing to address the underlying disorder; red cell transfusion is, therefore, not an appropriate treatment for chronic anaemia. Patients with anaemia of chronic disease may benefit from iron therapy and/or erythropoiesis stimulating agents (ESAs). Intravenous iron should be considered since this can be given safely to patients with chronic diseases while intramuscular iron causes unacceptable adverse effects and oral iron has limited efficacy in chronic anaemia. CONCLUSION: The management of anaemia calls for the development of a specialist service together with education of all healthcare professionals and transfer of skills from areas of good practice. Improvement in the management of anaemia requires a fundamental change of attitude from healthcare professionals.

Anemia, Iron-Deficiency↗
PubMed2005

Evaluation of therapy for lymphoma.

Positron emission tomography (PET) using (18)F-fluorodeoxyglucose ((18)F-FDG) is the best noninvasive imaging technique for to assess response in patients suffering from lymphoma. Early response evaluation ("interim PET") after one, a few cycles, or at midtreatment can predict response, progression-free survival, and overall survival. We calculated from data of 7 studies an overall sensitivity to predict treatment failure of 79%, a specificity of 92%, a positive predictive value (PPV) of 90%, a negative predictive value (NPV) of 81%, and an accuracy of 85%. Although it is not yet indicated to change patient management based on residual (18)F-FDG uptake on interim scan in chemotherapy-sensitive patients, prospective studies evaluating the role of an interim PET in patient management clearly are warranted. (18)F-FDG PET also has an important prognostic role in relapsing patients after reinduction chemotherapy before high-dose chemotherapy (HCT) followed by autologous stem cell transplantation (ASCT). However, all chemotherapy-sensitive patients remain candidates for HCT followed by ASCT, even if (18)F-FDG PET showed residual (18)F-FDG uptake. We calculated from data of 3 studies an overestimated risk of relapse in 16% of all PET-positive patients. Some patients with residual (18)F-FDG uptake will have a good outcome after HCT followed by ASCT. (18)F-FDG PET is the imaging technique of choice for end-of-treatment evaluation. However, (18)F-FDG is not specific for tumoral tissue. Active inflammatory lesions and infectious processes can be falsely interpreted as malignant residual cells. However, a negative (18)F-FDG PET cannot exclude minimal residual disease. Consequently, it is always indicated to correlate PET findings with clinical data, other imaging modalities, and/or a biopsy. We calculated, from data of 17 studies in end-of-treatment evaluation, a sensitivity of 76%, a specificity of 94%, a PPV of 82%, a NPV 92%, and an accuracy of 89%.

Antineoplastic Agents↗
PubMed2005

Positron emission tomography imaging for lymphoma.

PURPOSE OF REVIEW: To review the current role and the limitations of F-fluorodeoxygenase positron emission tomography in the management of lymphoma, with a particular focus on studies published since January 2004. RECENT FINDINGS: F-fluorodeoxygenase positron emission tomography should be routinely performed at the initial diagnosis of patients with suffering from Hodgkin's disease because it adds useful informations to conventional staging techniques. Residual F-fluorodeoxygenase uptake is an important prognostic factor after one or a few cycles of chemotherapy, but it is clearly too early to change patient treatment on the basis of F-fluorodeoxygenase positron emission tomography results. F-fluorodeoxygenase positron emission tomography is the best noninvasive imaging technique after treatment; however, it is always indicated to correlate positron emission tomography findings with clinical data, other imaging modalities, a biopsy, or all three to reduce the risk of false positive results. There are some concerns about the positive predictive value of positron emission tomography after treatment, especially in childhood lymphoma. Clinicians should be aware of positron emission tomography findings in specific clinical conditions in this patient population. F-fluorodeoxygenase positron emission tomography combined with computed tomography offers advantages over the two used separately and read side by side. It may be particularly useful for the planning of radiation therapy or for the planning of a surgical biopsy. Several studies have shown that F-fluorodeoxygenase positron emission tomography is definitively superior to Ga scintigraphy. New radiotracers such as F-fluorothymidine may be useful for the noninvasive assessment of proliferation in vivo. SUMMARY: F-fluorodeoxygenase positron emission tomography has become the most important nuclear medicine imaging modality in the field of lymphoma. It should be routinely used in the treatment of lymphoma patients.

False Positive Reactions↗
PubMed2005

Anaemia management strategies: optimising treatment using epoetin beta (NeoRecormon).

Anaemia has a detrimental impact on quality of life and it is important that this condition is recognised and treated in patients with cancer. Epoetin beta is an effective and well-tolerated treatment of anaemia in patients with a wide range of solid and haematological malignancies. A study in patients with lymphoid malignancies confirms that epoetin beta is equally effective at the same overall weekly dose (30,000 IU weekly) when given once-weekly or three-times weekly. This once-weekly regimen has also proved effective in patients with solid tumours. Once-weekly treatment is more convenient for the patient, potentially improving compliance and is associated with reduced hospital administration costs. The majority of patients with cancer will respond to epoetin therapy with an increase in haemoglobin levels. However, it is of value to identify those patients who are likely to respond, so that cost-effectiveness can be improved. Despite much research into potential predictive factors, follow-up studies are required and clinical judgement remains key to managing the anaemia of cancer. In addition, studies suggest that intravenous iron supplementation can improve response to epoetin therapy in patients with functional iron deficiency. Epoetin beta offers an effective, safe and convenient therapy for the management of anaemia in patients with cancer. Ongoing studies are expected to lead to a greater understanding of the optimal use of epoetins in cancer-related anaemia.

Anemia, Iron-Deficiency↗
PubMed2005

Influence of exogenous oestrogen or (anti-) androgen administration on soluble transferrin receptor in human plasma.

The objective of this investigation was to study the effects of sex steroids on levels of haemoglobin (Hb) and haematocrit (Hct) and to analyse whether these effects can be related to levels of the soluble transferrin receptor (sTfR), a marker of erythropoietic activity. Nineteen male-to-female transsexuals were randomly assigned to either oral ethinyl oestradiol (EE) (n=12) or transdermal 17beta-oestradiol (E2) (n=7); both treatments included the anti-androgen cyproterone acetate (CA). Six male-to-female transsexuals were treated with CA only. Fifteen female-to-male transsexuals were treated with i.m. testosterone esters. The Hct, and levels of Hb, IGF-I, GH and sTfR were measured before and after 4 months of hormone administration. Androgen administration significantly increased the sTfR concentration by 31.5% (P=0.008) and increased levels of Hct, Hb and IGF-I. Both regimens of CA with oral EE and transdermal E2 reduced plasma testosterone similarly to castrate values and decreased Hb and Hct. The CA+oral EE combination induced a decrease in sTfR of 19.0% (P=0.002) which was not the case with CA+transdermal E2 (P=0.27). This cannot be explained by the profound decline in plasma testosterone which was similar with both regimens, but this difference could be related to the different effects of the two regimens on plasma IGF-I. This assumption is supported by the positive correlation that was found to exist between plasma sTfR and IGF-I after the interventions (P<0.05).

Adult↗
PubMed2005

Modulation of homing properties of primitive progenitor cells generated by ex vivo expansion.

BACKGROUND AND OBJECTIVES: The maintenance of adequate interactions with the bone marrow (BM) microenvironment is critical to ensure efficient homing of ex vivo-expanded hematopoietic cells. This study was intended to assess adhesion and migration properties of long-term culture-initiating cells (LTC-IC) harvested after self-renewal division in ex vivo culture and to determine their susceptibility to growth-inhibitory signals mediated by adhesion to BM stromal ligands. DESIGN AND METHODS: We used cell tracking to isolate primitive LTC-IC that had accomplished 1 or 2 divisions ex vivo. Adhesion, migration and growth inhibition of divided LTC-IC were determined in the presence of purified BM ligands, and compared to the properties of uncultured LTC-IC. RESULTS: As compared to undivided LTC-IC, adhesion and migration mediated by very late antigen (VLA)-4 integrin across both vascular cell adhesion molecule-1 (VCAM-1) and fibronectin (Fn) were downregulated in post-mitotic LTC-IC. Conversely, binding and motility via VLA-5 across Fn were stimulated. No changes occurred in LTC-IC interactions with intercellular adhesion molecule-1 (ICAM-1) or with E- or P-selectin. Proliferation of uncultured LTC-IC was inhibited by VLA-4-mediated binding to VCAM-1 and the CS-1 domain of Fn, as well as binding to P-selectin. Growth of ex vivo-generated LTC-IC became unresponsive to these 3 ligands but was suppressed through VLA-5 engagement by the cell binding domain of Fn. INTERPRETATION AND CONCLUSIONS: The generation of LTC-IC in expansion culture is associated with functional alterations of adhesion receptors, modulating not only binding and migration in the BM but also responsiveness to adhesion-mediated growth inhibitory signals. Such changes may limit homing and engraftment of expanded primitive stem/progenitor cells.

AC133 Antigen↗
PubMed2005

Mature erythrocyte indices: new markers of iron availability.

This study was aimed at evaluating mature erythrocyte indices as new markers of iron status. Contrarily to those in the whole red blood cell (RBC) population, mature erythrocyte parameters are valid markers of iron status that remain independent of erythropoietic activity. When reticulocytosis is low, these parameters are similar to whole RBC parameters.

Adult↗
PubMed2005

Efficacy of recombinant human erythropoietin therapy started one month after autologous peripheral blood stem cell transplantation.

On day 30 after autologous peripheral blood stem cell transplantation (PBSCT), 20 patients were randomized to receive either erythropoietin at a dose of 500 U/kg/week s.c. (Epo group) or no treatment (control group). After 3 weeks, hemoglobin (p<0.0001) and serum transferrin receptor (p<0.0001) concentrations were higher in the Epo group. Hb response (+2 g/dL) was achieved in 100% vs 28% (p<0.0001) and Hb correction (> or =13 g/dL) in 70% vs 10% (p=0.0238) of the patients, respectively. This is the first randomized study showing an efficacy of erythropoietin therapy on Hb levels after autologous PBSCT.

Aged↗