Childhood obesity and outcomes after bone marrow transplantation for patients with severe aplastic anemia.

The prevalence of obesity in the pediatric population has increased in the last 2 decades and represents a serious health concern, with potential impact on outcomes of hematopoietic cell transplantation (HCT). We studied the effect of weight by age-adjusted body mass index (BMI) percentile in 1,281 pediatric patients (age 2-19 years) with severe aplastic anemia who underwent HCT between 1990 and 2005. The study population was divided into 5 weight groups-underweight, risk of underweight, normal BMI range, risk of overweight, and overweight-according to age-adjusted BMI percentiles. Cox proportional hazards regression models for survival and acute graft-versus-host disease (aGVHD), performed using weight groups as the main effect and the normal BMI range (26th-75th percentile) as the baseline comparison, found higher mortality among overweight children (>95th percentile adjusted for age). Weight at transplantation did not increase the adjusted risk of grade III-IV aGVHD. The 1-year and 2-year overall survival rates were 60% and 59% for overweight children, compared with >70% in children with lower BMI at both time points (P < .001). Other significant factors associated with survival included race and region, donor type, conditioning regimens in related donor transplants, performance score, and year of transplantation. In conclusion, overweight children with aplastic anemia have worse outcomes after HCT. The impact of obesity on survival outcomes in children should be discussed during pretransplantation counseling.

Obesity does not preclude safe and effective myeloablative hematopoietic cell transplantation (HCT) for acute myelogenous leukemia (AML) in adults.

The incidence of excessive adiposity is increasing worldwide, and is associated with numerous adverse health outcomes. We compared outcomes by body mass index (BMI) for adult patients with acute myelogenous leukemia (AML) who underwent autologous (auto, n = 373), related donor (RD, n = 2041), or unrelated donor (URD, n = 1801) allogeneic myeloablative hematopoietic cell transplantation (HCT) using bone marrow or peripheral blood stem cells reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) from 1995 to 2004. Four weight groups by BMI (kg/m(2)) were defined: underweight <18 kg/m(2); normal 18-25 kg/m(2); overweight >25-30 kg/m(2); and obese >30 kg/m(2). Multivariable analysis referenced to the normal weight group showed an increased risk of death for underweight patients in the RD group (relative risk [RR], 1.92; 95% confidence interval [CI], 1.28-2.89; P = .002), but not in the URD group. There were no other differences in outcomes among the other weight groups within the other HCT groups. Overweight and obese patients enjoyed a modest decrease in relapse incidence, although this did not translate into a survival benefit. Small numbers of patients limit the ability to better characterize the adverse outcomes seen in the underweight RD but not the underweight URD allogeneic HCT patients. Obesity alone should not be considered a barrier to HCT.

Second unrelated donor hematopoietic cell transplantation for primary graft failure.

Failure to engraft donor cells is a devastating complication after allogeneic hematopoietic cell transplantation (HCT). We describe the results of 122 patients reported to the National Marrow Donor Program between 1990 and 2005, who received a second unrelated donor HCT after failing to achieve an absolute neutrophil count of >or=500/microL without recurrent disease. Patients were transplanted for leukemia (n = 83), myelodysplastic disorders (n = 16), severe aplastic anemia (n = 20), and other diseases (n = 3). The median age was 29 years. Twenty-four patients received second grafts from a different unrelated donor. Among 98 patients who received a second graft from the same donor, 28 received products that were previously collected and cryopreserved for the first transplantation. One-year overall survival (OS) after second transplant was 11%, with 10 patients alive at last follow-up. We observed no differences between patients who received grafts from the same or different donors, or in those who received fresh or cryopreserved product. The outcomes after a second allogeneic HCT for primary graft failure are dismal. Identifying risk factors for primary graft failure can decrease the incidence of this complication. Further studies are needed to test whether early recognition and hastened procurement of alternative grafts can improve transplant outcomes for primary graft failure.

Donor and recipient chemokine receptor CCR5 genotype is associated with survival after bone marrow transplantation.

Despite continual improvement, morbidity and mortality after hematopoietic stem cell transplantation (HSCT) remain high. The importance of chemokines in HSCT lies in their regulation of immune responses that determine transplantation outcomes. We investigated the role of recipient and donor chemokine system gene polymorphisms by using a candidate gene approach on the incidence of graft-versus-host disease and posttransplantation outcomes in 1370 extensively human leukocyte antigen-matched, unrelated donor-recipient pairs by using multivariate Cox regression models. Our analysis identified that recipients homozygous for a common CCR5 haplotype (H1/H1) had better disease-free survival (DFS; P = .005) and overall survival (P = .021). When the same genotype of both the donor and recipient were considered in the models, a highly significant association with DFS and overall survival was noted (P < .001 and P = .007, respectively) with absolute differences in survival of up to 20% seen between the groups at 3 years after transplantation (50% DFS for pairs with recipient CCR5 H1/H1 vs 30% for pairs with donor CCR5 H1/H1). This finding suggests that donor and/or recipient CCR5 genotypes may be associated with HSCT outcome and suggests new diagnostic and therapeutic strategies for optimizing therapy.

High-dose chemotherapy with blood or bone marrow transplants for rhabdomyosarcoma.

Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in children, is cured with conventional therapy in 70%. However, the 5-year survival for those who relapse is about 30%, and drops to about 15% for those with unfavorable histologies (alveolar/undifferentiated subtypes). We describe outcomes of 62 subjects receiving autologous blood/bone marrow (BM) transplants for RMS between 1989 and 2003, and reported to the Center for International Blood and Marrow Transplantation Research (CIBMTR). Histologic subtype was confirmed by reviewing pathology reports. Treatment-related mortality (TRM), progression-free survival (PFS), and overall survival (OS) were evaluated. Overall, 73% of subjects were <20 years; 39% had cancer bulk >5 cm, 63% had metastasis at diagnosis, 55% had unfavorable histologies, 92% had cancer responsive to chemotherapy pretransplant, and 67% were in first remission. The 1-year TRM was 5% (95% confidence interval [CI], 1%-12%) and the 5-year PFS and OS were 29% (95% CI, 18%-41%) and 32% (95% CI, 21%-44%), respectively. There was only a 4% relapse rate after the first year. There were no differences in 5-year PFS or survival based on histological subtype, transplant in first remission versus relapse (36% versus 29%; P = .5), or transplantation for poor-risk histologies in first remission versus relapse (34% versus 33%; P = .9). Our data indicate that autotransplants for RMS disease are typically done in patients with disease responsive to chemotherapy pretransplant, with approximately one-third long-term survivors. Despite high-risk factors, we also found a low TRM, perhaps reflecting the migration from marrow to blood stem cells as the graft source. Even when performed after relapse for alveolar/undifferentiated histologies, long-term survivals were seen seemingly better than results with conventional therapies.

Outcomes following HSCT using fludarabine, busulfan, and thymoglobulin: a matched comparison to allogeneic transplants conditioned with busulfan and cyclophosphamide.

We have reported a lower incidence of acute graft-versus-host disease (aGVHD) with a novel conditioning regimen using low-dose rabbit antithymocyte globulin (ATG; Thymoglobulin [TG]) with fludarabine and intravenous busulfan (FluBuTG). To assess further this single-center experience, we performed a retrospective matched-pair analysis comparing outcomes of adult patients transplanted using the FluBuTG conditioning regimen with matched controls from patients reported to the CIBMTR receiving a first allogeneic hematopoietic stem cell transplant (HCT) after standard oral busulfan and cyclophosphamide (BuCy). One hundred twenty cases and 215 matched controls were available for comparison. Patients receiving FluBuTG had significantly less treatment related mortality (TRM; 12% versus 34%, P < .001) and grades II-IV aGVHD (15% versus 34%, P < .001) compared to BuCy patients. The risk of relapse was higher in the FluBuTG patients (42% versus 20%, P < .001). The risks of chronic GVHD (cGVHD) and disease free survival (DFS) were similar in the cases and controls. These results suggest that the novel regimen FluBuTG decreases the risk of aGVHD and TRM after HLA-identical sibling HSCT, but is associated with an increased risk of relapse, resulting in similar DFS. Whether these conditioning regimens may be more suitable for specific patient populations based on relapse risk requires testing in prospective randomized trials.