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Biomedical subjects

G Andreu

Publications and source records attributed to G Andreu.

At least 37 records · Page 2Linked to original sources
PubMed1998

Autologous stem-cell transplantation for non-Hodgkin's lymphomas: the role of graft purging and radiotherapy posttransplantation--results of a retrospective analysis on 120 patients autografted in a single institution.

PURPOSE: To analyze retrospectively survival and prognostic factors of patients with non-Hodgkin's lymphoma (NHL) autografted from 1979 to 1995 in a single institution. PATIENTS AND METHODS: A total of 120 patients, 64 with aggressive and 56 with low-grade NHL, were autografted. The carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) regimen was used in 104. The autograft was marrow in 101 patients. Marrow was purged in vitro by mafosfamide for 63 patients (adjusted dose [AD] in 32; unique dose [UD] in 31); 27 patients received a CD34+-selected graft. Following intensification, 45 patients received additional radiotherapy on previous sites of involvement. RESULTS: Outcome at 5 years for patients transplanted with low-grade NHL in first complete remission (CR1), in first partial remission (PR1), and in second complete remission (CR2) or beyond showed an event-free survival (EFS) of 75% +/- 12%, 46% +/- 18%, and 57% +/- 24%, a relapse incidence (RI) of 21% +/- 12%, 49% +/- 19%, and 43% +/- 25%, and a transplant-related mortality (TRM) of 5% +/- 5%, 10% +/- 7%, and 0%, respectively. For patients with aggressive NHL transplanted in CR1, in PR1, in CR2 or beyond, and in resistant relapse or in primary refractory disease, the EFS was of 73% +/- 9%, 58% +/- 19%, 29% +/- 16%, and 10% +/- 9%, the RI 22% +/- 9%, 14% +/- 9%, 77% +/- 18%, and 66% +/- 20%, and the TRM 6% +/- 6%, 32% +/- 21%, 11% +/- 10%, and 71% +/- 22%, respectively. In patients autografted upfront in first remission, additional radiotherapy was associated with a higher EFS, in univariate (P = .03) and multivariate analysis (P = .02, relative risk [RR] = .021). The role of graft purging with mafosfamide on the outcome reflected by the dose of colony-forming unit-granulocyte-macrophage (CFU-GM) per kilogram infused postpurging was assessed by univariate analysis: patients in first remission who received lower doses of CFU-GM had a lower RI and a higher EFS. CONCLUSION: This retrospective analysis suggests that marrow purging and posttransplant radiotherapy improve the outcome of patients with NHL autografted in first remission.

Adult↗
PubMed1997

Extracorporeal photochemotherapy: a treatment for organ graft rejection.

Extracorporeal photochemotherapy (ECPC) has been investigated experimentally and in clinical conditions in transplant rejection treatment and prevention. Repeated injections of photochemically modified syngeneic alloreactive T cells prior to transplant significantly delay rejection in a mouse skin graft model as well as in a heterotopic heart transplant model in rats. In the latter, we found this effect to be dependent on 3 main parameters, i.e., treatment intensity (number of injections), schedule (injections before and after transplant), and associated immunosuppression (because there is no detectable effect in animals without immunosuppression). In human beings, ECPC was first used for the treatment of acute rejection episode after heart transplantation. At least 2 studies provided evidence that ECPC is as effective as high dose corticosteroids in controlling moderate acute rejections, and several case reports showed that ECPC could be effective in recurrent and/or steroid resistant rejections. ECPC has also been investigated in an open trial to prevent rejection episodes after heart transplantation in patients at high risk of acute rejection because of human leukocyte antigen (HLA) immunization and/or a second or third transplant and found to be successful. In heart transplant recipients at standard risk of rejection episodes, a small scale randomized trial showed a reduction in both rejection episodes and infections in the ECPC treated vs. the standard group. Beyond these studies and other isolated case reports, several large scale randomized trials in heart, lung, and even kidney transplantations (some of them already ongoing), will enable us to define the role of ECPC in the management of transplant recipients.

Animals↗
PubMed1996

[Why remove leukocytes from labile blood products in 1995?].

During the last 15 years, the techniques to prepare leukocyte-poor cellular blood components greatly improved, as well as our knowledge about the role of leukocytes in many adverse effects of transfusion. These two facts favor the extension of indication of leukocyte-poor blood components. Leukocytes in blood components may be detrimental to their storage, due to their metabolic needs and to their progressive lysis, leading to the release of cytokines. Leukocytes are the exclusive vector in blood of CMV and HTLV viruses. Leukocytes are a key element of the immune modifications induced by transfusion. HLA alloimmunization is favored by the transfusion of large quantities of leukocytes HLA different from the recipient whose immune functions are intact. Conversely, the risk of transfusion associated graft versus host disease is dependent of the transfusion of mature T lymphocytes sharing a partial identity with the recipient, and/or an immune deficient status of the recipient. Between these two extremes, many other effects related to the presence of leukocytes in cellular blood components, as are the transfusion effect observed in transplant recipients, the increased risk for bacterial infection after transfusion, the increased risk for tumor recurrence or the reactivation of virus infections, remain to be fully understood. Despite recent significant improvements, further studies, experimental as well as clinical, will be needed to expand the indications of leukocyte-poor blood components.

Bacterial Infections↗
PubMed1996

[Viral attenuation of labile blood products].

Viral inactivation is one of the possibilities to reduce the residual risk of blood products. It is now applied to all plasma derived products (PDP). Application of such techniques to labile blood products (LBP) is difficult for two main reasons: any method should inactivate cell-associated viruses and should avoid any injury of the cells constituting the active ingredient. Physical techniques may reduce the viral content of cellular BPL (leucodepletion, washing, gamma irradiation), but none of them is active enough to comply with the present requirements for efficacy. An important work has been dedicated to the development of virus photoinactivation techniques. They consist of the addition of a photoreagent followed by illumination at an appropriate wavelength which results in a photochemical reaction responsible for the viral inactivation. Treatment of platelet concentrates by psoralen derivatives and UV-A illumination significantly inactivate in vitro enveloped and naked viruses, free and cell-associated viruses and also sequences integrated in the viral genome. Recent progresses have led to these results without detectable functional alteration of platelets and mutagenicity. Viral inactivation of red blood cells yet did not reach the same level because hemoglobin does not allow the use of the photoreagent compounds applicable to platelet concentrates. Viral decontamination of fresh frozen plasma by solvent and detergent, active on enveloped viruses, has been used in France since 1992. Other techniques of comparable efficacy, have received an agreement in other countries. The research on viral inactivation of LBP could prove to be of great importance in the near future in bringing additional safety to patients not only for the residual viral risk but maybe also for the residual bacterial risk of LBP.

Antiviral Agents↗
PubMed1996

[Difference in costs of autologous transplantation of peripheral and bone marrow hematopoietic stem cells. A retrospective analysis over 1 year of transplantation in lymphoma, Hodgkin's disease and myeloma in a Center].

The study analysed the financial benefits of transplantation with peripheral blood stem-cells primed after chemotherapy and growth factor in comparison with bone marrow transplantation. Twenty-three consecutive transplantations were performed during one year: 14 peripheral blood stem-cell (CSC group) and 9 bone marrow transplantations (MO group). No differences in patients characteristics were seen between the two groups except for higher number of "BEAM" conditioning in CSC group. Were analyzed delay in neutrophil and platelet recovery, numbers of days in hospital, with fever, under antibiotics, costs of supportive therapy, stem-cell collection and cryopreservation. Difference was significant for duration of neutropenia with advantages in CSC group, but the number on days in hospital, with fever or under antibiotics were similar. Number of platelet transfusions was reduced in CFC group: this economical advantage was lost with the cost of growth factor used for priming stem-cells stem-cell collections and cryopreservations. In our retrospective study, financial advantages associated to peripheral blood stem-cell transplantation was not verified.

Adolescent↗
PubMed1995

[Platelet collection by apheresis with reduced use of citrate: quantitative and qualitative evaluation of three protocols].

Three protocols of platelet collection by apheresis on Cobe Spectra with different citrate concentrations were compared. First we determined until what level we could diminish the ratio anticoagulant/whole blood flow to enhance the efficiency without clotting in the cell separator by platelet aggregates. We found that protocol 2 had a better platelet collection efficiency than the standard protocol 1: respectively 59% versus 52%. Protocol 3 had even a better efficiency but, due to the risk of clotting (5% of the procedures) we rejected it for routine use. We compared in vitro platelet functions of protocols 1 and 2 by aggregometry in vitro. The results with the different aggregating agents indicated that the less citrated environment kept the platelets more functional in vitro. A disadvantage of protocol 2 compared to the standard protocol is the more important number of platelet concentrates that contain more than 10(6) leucocytes.

Adult↗
PubMed1994

Extracorporeal photochemotherapy: evaluation of two techniques and use in connective tissue disorders.

Extracorporeal photochemotherapy (ECP) consists of collection of mononuclear cells, their irradiation with UV-A light in the presence of a photoactivable molecule--8-methoxy-psoralen (8-MOP) being the most widely used--and their reinjection into a patient. Two technical approaches have been developed. The photopheresis procedure involves four steps: (i) 8-MOP is given to the patient orally, 2 h before collection of white blood cells; (ii) a discontinuous flow cell separator (UVAR, Therakos, West Chester, PA, U.S.A.) is used for cell collection. The final product (740 mL) has a hematocrit of 4.5 +/- 1.7%); (iii) irradiation, performed with the same UVAR apparatus, begins before all the cells are collected, and lasts for 180 min after collection; and (iv) after irradiation, the buffy-coat is reinjected into the patient. We developed a technique summarized as follows: (i) mononuclear cell collection is performed using the Spectra (Cobe, Denver, CO, U.S.A.) cell separator, which provides a highly enriched mononuclear cell concentrate (always > 90% purity), in a small volume < 150 mL, subsequently adjusted to 300 mL for irradiation. Hematocrit of the final product is always < 2%. (ii) Soluble 8-MOP is added to the mononuclear cell concentrate at a final concentration of 200 ng/mL. (iii) Mononuclear cell concentrate is transferred in an EVA plastic bag (Macopharma, Tourcoing, France) to ensure an efficient irradiation with a UV irradiator (Vilber Lourmat, Marne-la-Vallée, France). (iv) After irradiation at 2 J/cm2 (time < 20 min), the cells are reinfused into the patient. Experimental and clinical data suggest that ECP has potential applications in the treatment of connective tissue disorders, such as systemic sclerosis and rheumatoid arthritis. Although encouraging data have been obtained, further clinical trials are warranted to establish the role of this therapy in these indications.

Animals↗
PubMed1993

[Treatment of refractory rheumatoid polyarthritis by extracorporeal photochemotherapy].

Extracorporeal photochemotherapy (EPC) has been used to treat cutaneous T-cell lymphomas as well as a number of immune-mediated disorders. Seven patients above 50 years of age with refractory rheumatoid arthritis (RA) were treated by EPC. Mononuclear cells were harvested, exposed to ultraviolet A light in the presence of 8-methoxypsoralen, then reinfused into the patient. This procedure was repeated eight times over a three-week period. Improvements in clinical parameters were seen in every case as early as the second week and persisted throughout the duration of EPC. Improvements for more than three months were observed in two patients. C-reactive protein levels declined during the treatment period. No adverse reactions were recorded. The mechanism of action of EPC in RA requires elucidation and a controlled study is needed to confirm the efficacy of this technique.

Aged↗