Recommendations on hematopoietic stem cell transplantation for inherited bone marrow failure syndromes.

Allogeneic hematopoietic stem cell transplantation (HSCT) offers the potential to cure patients with an inherited bone marrow failure syndrome (IBMFS). However, the procedure involves the risk of treatment-related mortality and may be associated with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks. IBMFS are rare, whereas case reports and small series in the literature illustrate highly heterogeneous practices in terms of indications for HSCT, timing, stem cell source and conditioning regimens. A consensus meeting was therefore held in Vienna in September 2012 on behalf of the European Group for Blood and Marrow Transplantation to discuss HSCT in the setting of IBMFS. This report summarizes the recommendations from this expert panel, including indications for HSCT, timing, stem cell source and conditioning regimen.

Impact of pretransplant minimal residual disease after cord blood transplantation for childhood acute lymphoblastic leukemia in remission: an Eurocord, PDWP-EBMT analysis.

To address the prognostic value of minimal residual disease (MRD) before unrelated cord blood transplantation (UCBT) in children with acute lymphoblastic leukemia (ALL), we analyzed 170 ALL children transplanted in complete remission (CR) after myeloablative conditioning regimen. In all, 72 (43%) were in first CR (CR1), 77 (45%) in second CR (CR2) and 21 (12%) in third CR (CR3). The median interval from MRD quantification to UCBT was 18 days. All patients received single-unit UCBT. Median follow-up was 4 years. Cumulative incidence (CI) of day-60 neutrophil engraftment was 85%. CI of 4 years relapse was 30%, incidence being lower in patients with negative MRD before UCBT (hazard ratio (HR)=0.4, P=0.01) and for those transplanted in CR1 and CR2 (HR=0.3, P=0.002). Probability of 4 years leukemia-free survival (LFS) was 44%, (56, 44 and 14% for patients transplanted in CR1, CR2 and CR3, respectively (P=0.0001)). Patients with negative MRD before UCBT had better LFS after UCBT compared with those with positive MRD (54% vs 29%; HR=2, P=0.003). MRD assessment before UCBT for children with ALL in remission allows identifying patients at higher risk of relapse after transplantation. Approaches that may decrease relapse incidence in children given UCBT with positive MRD should be investigated to improve final outcomes.

Single-unit umbilical cord blood transplantation from unrelated donors in patients with hematological malignancy using busulfan, thiotepa, fludarabine and ATG as myeloablative conditioning regimen.

Attempts to optimize outcomes in cord blood transplantation (CBT) by using new conditioning regimens and standardization of cord blood unit selection are warranted. In all, 88 patients (18 children and 70 adults) with hematological malignancy from nine Spanish institutions underwent a single-unit CBT after an i.v. BU-based myeloablative conditioning regimen. All evaluable patients except one engrafted. The overall cumulative incidence (CI) of myeloid engraftment was 94% at a median time of 19 days. In multivariate analysis, nonadvanced disease stage was the only factor with a favorable impact on myeloid engraftment. The CI of acute GVHD grades II-IV and chronic extensive GVHD were 24% each. The CI of nonrelapse mortality at 100 days, 180 days and 5 years was 14, 23 and 44%, respectively. The 5-year CI of relapse was 18%, whereas disease-free survival (DFS) was 46%, 39% and 11% for patients transplanted in early, intermediate and advanced stages of the disease, respectively. Our study shows high rates of engraftment with fast neutrophil recovery in patients undergoing single-unit CBT using a BU-based conditioning regimen. Long-term DFS can be achieved in a substantial number of patients with high-risk hematological malignancies, particularly when transplanted in an early stage of the disease.

Hematopoietic stem cell transplantation for advanced myelodysplastic syndrome in children: results of the EWOG-MDS 98 study.

We report on the outcome of children with advanced primary myelodysplastic syndrome (MDS) transplanted from an HLA-matched sibling (MSD) or an unrelated donor (UD) following a preparative regimen with busulfan, cyclophosphamide and melphalan. Ninety-seven patients with refractory anemia with excess blasts (RAEB, n=53), RAEB in transformation (RAEB-T, n=29) and myelodysplasia-related acute myeloid leukemia (MDR-AML, n=15) enrolled in the European Working Group of MDS in Childhood (EWOG-MDS) 98 study and given hematopoietic stem cell transplantation (HSCT) were analyzed. Median age at HSCT was 11.1 years (range 1.4-19.0). Thirty-nine children were transplanted from an MSD, whereas 58 were given the allograft from a UD (n=57) or alternative family donor (n=1). Stem cell source was bone marrow (n=69) or peripheral blood (n=28). With a median follow-up of 3.9 years (range 0.1-10.9), the 5-year probability of overall survival is 63%, while the 5-year cumulative incidence of transplantation-related mortality (TRM) and relapse is 21% each. Age at HSCT greater than 12 years, interval between diagnosis and HSCT longer than 4 months, and occurrence of acute or extensive chronic graft-versus-host disease were associated with increased TRM. The risk of relapse increased with more advanced disease. This study indicates that HSCT following a myeloablative preparative regimen offers a high probability of survival for children with advanced MDS.

Observational prospective study of viral infections in children undergoing allogeneic hematopoietic cell transplantation: a 3-year GETMON experience.

We studied surveillance, incidence and outcome of viral infections in children undergoing allogeneic hematopoietic cell transplantation (HCT) in the main pediatric transplant units in Spain. We prospectively collected data from first year post-HCT in every consecutive allogeneic HCT performed during 3 years (N = 215): first HCT = 188 and second HCT = 27; median age = 6.6 years (0.1-20.7). Most patients had acute leukemia (N = 137) and 135 recipients (63%) were CMV seropositive. A total of 46 patients underwent cord blood transplant, 133 patients underwent HCT from alternative donors (62%) and 101 patients received anti-thymocyte globulin. Observational time was completed in 137 patients, whereas the remaining 78 died after a median survival time of 99 days (3-352). CMV was monitored in all patients; adenovirus (ADV) and human herpesvirus 6 (HHV-6) were monitored in 101 and 33 patients, respectively. We found 145 viral infections in 103 patients: CMV (n = 42), ADV (n = 32), HHV-6 (n = 7), polyomavirus (n = 20), EBV (n = 6), VZV (n=17) and others (n = 8). CMV infection was significantly higher in seropositive patients (25 vs 7%) (P = 0.02). Extensive chronic GVHD (cGVHD) was significantly associated with an increased rate of viral infections (12 of 16 patients with cGVHD had infections vs 91 of 199 without GVHD) (P = 0.035). In total, 10 patients (4.6%) died of viral infections (CMV = 5, ADV = 3, respiratory = 2). We found a high incidence of viral infection, but mortality was low.

Secondary malignancies and quality of life after stem cell transplantation.

Malignant diseases (MD) occurring after stem cell transplantation (SCT) are of particular concern as increasing number of patients survive and remain free of their original disease. The cumulative incidence at 15 years is 10-12%. The B-cell proliferative disorders (BCLP) are the most common MD in the first year after SCT; the incidence probability is 1% in allogeneic transplants but is much higher (until 14%) after HLA-identical, T-cell-depleted SCT in which Campath 1G or ATG are given. BCLP develop because of reactivation of the EBV and a depressed cellular immunity. Prediction of risk of BCLP can be made by frequent monitoring of EBV load in patients with risk factors. The most effective therapies are the early administration of anti-CD20 monoclonal antibody and adoptive immunotherapy with in vitro generated EBV-specific cytotoxic T cells. Myelodysplasia and acute myeloid leukemia with very poor prognosis have been described in 4-18% of patients with non-Hodgkin lymphoma and Hodgkin disease, 12-24 months after autologous SCT. The risk of development of solid tumors increases over time and the cumulative incidence among children who underwent an SCT at less than 10 years of age is 6-11% at 15 years. There are few studies evaluating quality of life (QOL) in children and adolescents who had received an SCT. The findings of these studies can be summarized as follows: (a) The majority of long survivors enjoy good QOL and return successfully to school or work. (b) A minority (10-15%) complain of physical problems or present moderate cognitive or psychological dysfunctions. (c) The importance of family, other social support and psychological adjustments is generally recognized. More extensive, longitudinal and comparative studies with other alternative therapies are required.