Using EasyMatch® to anticipate the identification of an HLA identical unrelated donor: A validated efficient time and cost saving method.

In the absence of an HLA matched familial donor, a search for an unrelated donor or cord blood unit is initiated through worldwide registries. Although a first look-up on available HLA information of donors in the "book" at BMDW (Bone Marrow Donor Worldwide) can provide a good estimation of the number of compatible donors, the variety of resolution typing levels requires confirmatory typing (CT) which are expensive and time consuming. In order to help recipient centers in their work. The French donor registry (France Greffe de Moelle/Agence de la Biomedecine) has recently developed a software program called "EasyMatch®" that uses haplotype frequencies to compute the likelihood of phenotypic match in donors according to various typing resolution levels. The goal of our study is to report a single monocentric user-experience with EasyMatch®, demonstrating that its routine use reduced the cost and the delay of the donor search in our center, allowing the definition of a new strategy to search compatible unrelated donors. The strategy was first established on a retrospective cohort of 217 recipients (185 adults and 32 children=before score) and then validated on a prospective cohort of 171 recipients (160 adults and 11 children=after score). For all patients, we calculated the delay between the registration day and the donor identification day, and the number of CT requested to the donor centre. Considering both groups, we could observe a significant decrease of the number of CT from 8 to 2 (p<0,001), and a significant decrease of the median delay to identify a suitable donor from 43 to 31days (p<0.0001). EasyMatch® estimates the number of potentially identical donors, but doesn't foresee availability of the donors. It provides us an easy tracking of mismatches, an estimation of the number of potential donors, the selection of population following ethnic origin of patients and a high prediction when probability is high or low. It affords a new approach of donor search in our daily work and improves the efficiency in the great challenge of the compatible donor identification.

Impact of anti-HLA antibodies on allogeneic hematopoietic stem cell transplantation outcomes after reduced-intensity conditioning regimens.

Anti-human leukocyte antigen (HLA) antibodies are associated with several complications in solid organ transplantations, but their impact after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is not yet well defined. To evaluate the relevance of anti-HLA antibodies, we have retrospectively analyzed 107 peripheral blood allo-HSCTs after reduced-intensity conditioning regimen between 2005 and 2010. Acute myeloid leukemia and multiple myeloma were the most frequent malignancies in the cohort. The detection of anti-HLA antibodies was systematically performed in all patients before transplantation. Anti-HLA antibodies were present in 24 patients (22%). There was no significant impact of anti-HLA antibodies on engraftment, incidence of relapse, and incidence of acute graft-vs-host disease. The presence of anti-HLA antibodies was associated with significantly worse overall survival (p = 0.006) and event-free survival (p = 0.024) after stratification on sex. The 3-year probability of overall survival was 34% without anti-HLA antibodies and 16% in their presence. Patients with anti-HLA antibodies had a higher transplant-related mortality associated with life-threatening vascular complications. Our study supports that anti-HLA antibodies should be tested and considered as an important impacting factor for transplantation outcomes after reduced-intensity conditioning allo-HSCT. We recommend its consideration before allo-HSCT in the donor-recipient selection parameters.

Phase II prospective study of treosulfan-based reduced-intensity conditioning in allogeneic HSCT for hematological malignancies from 10/10 HLA-identical unrelated donor.

Different RIC regimens were evaluated prior to allo-HSCT in different hematological malignancies. We conducted this prospective study in adult patients with various hematological malignancies in order to evaluate the toxicity and efficacy of treosulfan-based conditioning, followed by allo-HSCT from 10/10 HLA-identical unrelated donors. Conditioning included treosulfan 12 g/m(2)/day i.v. (day -6 to day -4), fludarabine 30 mg/m(2)/day i.v. (day -6 to day -2), and ATG 2.5 mg/kg/day (day -2 to day -1). PBSC were used as HSC source. We included 56 patients (29 AML, 9 MM, 8 MDS, 6 CLL, 3 ALL, and 1 CML) with a median age of 57 years (18-65.5). Fifty-four (96%) patients engrafted; the cumulative incidence of aGVHD grade ≥II at 3 months reached 31%. The cumulative incidence of cGVHD at 18 months was 34% limited and 8% extensive. The median overall survival (OS) was not reached with a 3-year probability of 52%. The cumulative incidence of relapse at 3 years was 25%, and the cumulative incidence of transplant-related mortality (TRM) at 12 and 24 months was 20% and 23%, respectively. Treosulfan appears to be a good alternative for conditioning of MUD transplant patients with promising results in terms of OS, relapse, and TRM.