[Hyperbaric oxygen and radiotherapy: From myth to reality]. / Oxygénothérapie hyperbare et radiothérapie : entre mythe et réalité.

Worldwide, more than a million people receive each year a curative radiotherapy. While local control and overall survival are steadily increasing, 5 to 15% of patients still develop above grade 2 late toxicities. Late toxicities treatments are complex. Hyperbaric oxygenation was shown to induce revascularization and healing of injured tissues, but indications are still debated. Through a literature review, we summarized the hyperbaric oxygenation indications in radiation-induced late toxicities. We also studied the knowledge and practice of French local radiation therapists. It seems that hyperbaric oxygen therapy can be a conservative treatment of haemorrhagic cystitis and radiation-induced pain, in case of drug therapies failure. Often associated with a significant morbidity and mortality, surgery could be avoided. The risk of complications in case of tooth extraction in irradiated tissues is also reduced. However, the role of hyperbaric oxygenation for mandibular osteoradionecrosis, radiation-induced proctitis, enteritis, lymphoedema, brachial plexopathy, skin and neurological sequelae seems more questionable since studies results are conflicting. Future outcomes of phase III studies are expected to clarify the role of hyperbaric oxygenation in the management of radio-induced toxicities, including for head and necks complications.

Collaboration between hematopoietic stem cell donor registry and cord blood banks.

Despite the huge number of volunteer donors registered worldwide, only a mean of 50% of patients not having a family donor are transplanted with an unrelated donor. Since 1990, a network has been implemented among some European registries. With the help of the European Community, a more sophisticated network has been developed, the European Marrow Donor Information System (EMDIS). A new project underwent development by registries and the Bone Marrow Donor Worldwide: the EMDIS Cord Blood Registry. It will in the future permit to obtain after a search request, one report containing all of the best donors worldwide and best umbilic cord blood for each patient, taking into account possible double cord blood transplantations and other factors, such as number of nucleated cells, number of CD34+ cells, and methods of reduction. Only a strong collaboration between all hematopoietic stem cell registries and cord blood banks would allow a Registry to propose the best donor/cord blood unit for each patient in each country. Progress in the field of hematopoietic stem cell transplantation may be obtained by the parallel development of cord blood banks worldwide and bone marrow donor registries among countries that include minorities.

Antithymocyte globulins and chronic graft-vs-host disease after myeloablative allogeneic stem cell transplantation from HLA-matched unrelated donors: a report from the Sociéte Française de Greffe de Moelle et de Thérapie Cellulaire.

This retrospective report assessed the impact of rabbit antithymocyte globulins (ATG), incorporated within a standard myeloablative conditioning regimen prior to allogeneic stem cell transplantation (allo-SCT) using human leukocyte antigen-matched unrelated donors (HLA-MUD), on the incidence of acute and chronic graft-vs-host disease (GVHD). In this series of leukemia patients, 120 patients (70%) did not receive ATG ('no-ATG' group), whereas 51 patients received ATG ('ATG' group). With a median follow-up of 30.3 months, the cumulative incidence of grade 3-4 acute GVHD was 36% in the no-ATG group and 20% in the ATG group (P = 0.11). The cumulative incidence of extensive chronic GVHD was significantly lower in the ATG group as compared to the no-ATG group (4 vs 32%, respectively; P = 0.0017). In multivariate analysis, the absence of use of ATG was the strongest parameter associated with an increased risk of extensive chronic GVHD (relative risk) = 7.14, 95% CI: 1.7-33.3, P = 0.008). At 2 years, the probability of nonrelapse mortality, relapse, overall and leukemia-free survivals was not significantly different between the no-ATG and ATG groups. We conclude that the addition of ATG to GVHD prophylaxis resulted in decreased incidence of extensive chronic GVHD without an increase in relapse or nonrelapse mortality, and without compromising survival after myeloablative allo-SCT from HLA-MUD.

Haematopoietic stem cell donor registries: World Marrow Donor Association recommendations for evaluation of donor health.

The ability to identify unrelated haematopoietic stem cell donors in one country for recipients in another country requires cooperation and standardization in many areas. The donor assessment and testing are very important issues affecting quality and safety of donation. This special report details the World Marrow Donor Association's recommended procedures regarding the medical evaluation of donors, with the intent to protect the volunteer from the risk to damage his health and to offer the recipient the appropriate quality of stem cells. This document describes criteria for permanent or temporary deferral, guidelines for risk evaluation of infectious disease, examples of conditions requiring assessment and questionnaires designed to elicit relevant information about a donor's medical history and general health.

[Economic evaluation of the organization of a registry of haematopoietic stem cell donors]. / Evaluation économique de l'organisation d'un registre de donneurs de cellules souches hématopoïétiques.

BACKGROUND: Availability of a healthy, human-leukocyte-antigen-matched hematopoietic stem cell source is a prerequisite for successful allogenic hematopoietic stem cell transplantation. In 70% of cases, the search of hematopoietic stem cells shifts from siblings to unrelated donor registries. Given that the Human Leucocytes Antigens (HLA) system is highly polymorphic and that the cost of HLA typing remains high, the adequacy between registry content and patient needs must be assessed. Registries should be optimally organized to increase the probability for any given patient to find a donor. METHODS: A welfare function associated with the existence of an HLA registry was defined as was a measure of the advantage for laboratories having performed HLA typing. We hypothesized a way to formalize registry efficiency and applied it to the French Hematopoietic Stem Cell donors Registry. RESULTS: The model determined an implicit value for the stem cell graft and showed that efficiency increased very slowly with increasing number of potential donors in registries. The optimal size of a registry was found to be sensitive to model parameters. CONCLUSION: Increased registry size, in terms of number of donors foreseeable in the French registry, would have a limited impact on registry efficiency and thus social effectiveness. Nevertheless, the calibration of the model justifies the goal of recruiting 100000 new volunteer donors over the next 10 years as proposed by the French government in the "Graft Plan". The policy of the regulatory agency should be oriented towards improving the probability a compatible potential donor identified during a preliminary search would become an actual fully compatible donor and towards reducing the cost of typing.

World Marrow Donor Association guidelines for use of HLA nomenclature and its validation in the data exchange among hematopoietic stem cell donor registries and cord blood banks.

Since the advent of the European Marrow Donor Information System in the first half of the last decade, fully automated data exchange between registry computer systems has been playing an ever-increasing role in the international search for unrelated donors of blood progenitor cells. This exchange, however, was hampered by different local conventions used to present HLA data and complicated by the need to extend the official WHO nomenclature to accommodate the registries' information systems and to cross-validate HLA data obtained with different methods and/or at different loci. The guidelines presented here have been developed by the World Marrow Donor Association to standardize the nomenclature to be used and the validation checks to be applied in the international electronic exchange of HLA-typing data among unrelated volunteer hematopoietic stem cell donor registries and umbilical cord blood banks. Two reference web sites have been designated to maintain and update the approved HLA nomenclature and all the ancillary information needed by the conventions described here.

Strategies for new donor typing based on donor HLA type or donor characteristics.

Registries of volunteer unrelated haematopoietic stem cell donors must make decisions on the procedures used to human leukocyte antigen type new donors based on various factors including available finances and donor diversity. This manuscript describes a comparison of new donor typing strategies for three European registries which was presented for discussion at the 14th International Histocompatibility Workshop.

Relevance of KIR gene matching in unrelated hematopoietic stem cell transplantations.

The aim of this collaborative study was to evaluate the impact of killer cell immunoglobulin-like receptor (KIR) gene disparities on unrelated hematopoietic stem cell transplantations (HSCT) outcome. To address this question, we have determined the presence or absence of 14 functional KIR genes in HLA-matched (n= 164) or HLA-mismatched (n= 100) donor/recipient pairs and investigated whether KIR gene disparities had an impact on both the occurrence of acute graft-vs-host-disease incidence and overall survival. In a univariate analysis, our preliminary results suggest a detrimental effect of a few KIR gene disparities on patient survival that should be avoided in unrelated HSCT.

World Marrow Donor Association: international standards for unrelated hematopoietic stem cell donor registries.

World Marrow Donor Association standards are aimed at enhancing the quality of unrelated volunteer donor hematopoietic stem cell registries assisting transplant physicians in the international search for unrelated donors for their patients. The standards cover: (1) general organization of registries; (2) donor recruitment; (3) donor characterization; (4) information technology; (5) facilitation of search requests; (6) second/subsequent donations; (7) collection/processing/transport of stem cells; (8) follow-up of patient/donor; and (9) financial/legal responsibilities.

A special report: suggested procedures for international unrelated donor search from the donor registries and quality assurance working groups of the World Marrow Donor Association (WMDA).

This special report details the World Marrow Donor Association's recommended procedures regarding the international search for an unrelated donor for hematopoietic stem cell transplantation. The responsibilities of the national hubs, transplant center and donor registry staff are outlined for all actions associated with the preliminary search, formal search, donor confirmatory typing and final donor selection.