Long-term follow-up and factors influencing outcomes after related HLA-identical cord blood transplantation for patients with malignancies: an analysis on behalf of Eurocord-EBMT.

We analyzed risk factors influencing outcomes after related (R) human leukocyte antigen-identical cord blood transplantation (CBT) for 147 patients with malignancies reported to Eurocord-European Group for Blood and Marrow Transplantation. CBT has been performed since 1990; median follow-up was 6.7 years. Median patient age was 5 years. Acute leukemia was the most frequent diagnosis (74%). At CBT, 40 patients had early, 70 intermediate, and 37 advanced disease. CB grafts contained a median of 4.1 × 10(7)/kg total nucleated cells (TNCs) after thawing. The cumulative incidence (CI) of neutrophil recovery was 90% at day +60. CIs of acute and chronic graft-versus-host disease (GVHD) were 12% and 10% at 2 years, respectively. At 5 years, CIs of nonrelapse mortality and relapse were 9% and 47%, respectively; the probability of disease-free survival (DFS) and overall survival were 44% and 55%, respectively. Among other factors, higher TNCs infused was associated with rapid neutrophil recovery and improved DFS. The use of methotrexate as GVHD prophylaxis decreased the CI of engraftment. Patients without advanced disease had improved DFS. These results support banking and use of CB units for RCBT. Cell dose, GVHD prophylaxis not including methotrexate, and disease status are important factors for outcomes after RCBT.

Umbilical cord blood transplantation for children with thalassemia and sickle cell disease.

We examined the efficacy of unrelated cord blood (CB) transplantation in children with thalassemia (n = 35) and sickle cell disease (n = 16), using data reported to 3 registries. Donor-recipient pairs were matched at HLA-A and -B (antigen level) and DRB1 (allele level) in 7 or HLA mismatched at 1 (n = 18), 2 (n = 25), or 3 loci (n = 1). Transplant conditioning was myeloablative (n = 39) or reduced intensity (n = 12). Neutrophil recovery with donor chimerism was documented in 24 patients; 11 patients developed grade II-IV acute graft-versus-host disease (aGVHD) and 10 patients, chronic GVHD (cGVHD). Overall survival (OS) and disease-free survival (DFS) were 62% and 21% for thalassemia and 94% and 50% for sickle cell disease (SCD), respectively. In multivariate analysis, engraftment rate (hazard ratio [HR] 2.2, P = .05) and DFS (HR 0.4, P = .01) were higher with cell dose >5 × 10(7)/kg. The 2-year probability of DFS was 45% in patients who received grafts with cell dose >5 × 10(7)/kg and 13% with lower cell dose. Primary graft failure was the predominant cause of treatment failure occurring in 20 patients with thalassemia and 7 patients with SCD. Primary graft failure was fatal in 5 patients with thalassemia. These results suggest that only CB units containing an expected infused cell dose >5 × 10(7)/kg should be considered for transplantation for hemoglobinopathy.