Allogeneic stem-cell transplantation for patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) has been performed primarily with an HLA matched donor. Outcomes of haploidentical transplantation have recently improved, and a comparison between these donor sources in a uniform cohort of patients has not been performed. We evaluated outcomes of 227 patients with AML/MDS treated with melphalan-based conditioning. Donors were matched related (MRD) (N=87, 38%), matched unrelated (MUD) (N=108, 48%), or haploidentical (N=32, 14%). No significant differences were found between haploidentical and MUD transplant outcomes; however, there was a trend for improved outcomes in the MRD group with a 3-year progression-free survival for patients in remission of 57%, 45% and 41% for MRD, MUD and haploidentical, respectively (P=0.417). Recovery of T-cell subsets was similar for all groups. These results suggest that haploidentical donors can safely extend transplantation for AML/MDS patients without an HLA matched donor. Prospective studies comparing haploidentical and MUD transplants are warranted.

For patients with acute lymphoblastic leukemia (ALL) who relapse after allogeneic hematopoietic stem cell transplantation (HSCT), treatment options are limited, and the clinical course and prognostic factors affecting outcome have not been well characterized. We retrospectively analyzed outcomes of 123 adult patients with ALL who relapsed after a first HSCT performed at our center between 1993 and 2011. First-line salvage included second HSCT (n = 19), donor lymphocyte infusion with or without prior chemotherapy (n = 11), radiation therapy (n = 6), cytoreductive chemotherapy (n = 30), mild chemotherapy (n = 27), or palliative care (n = 23), with median postrelapse overall survival (OS) of 10 months, 6.5 months, 3 months, 4 months, 4 months, and 1 month, respectively. Despite a complete remission rate of 38% after first-line salvage in the treated patients, the OS rate remained limited with 1- and 2- year OS rates of 17% (95% confidence interval, 13 to 29) and 10% (95% confidence interval, 6 to 20), respectively. On univariate analysis, adverse factors for OS included active disease at the time of first HSCT and short time to progression from first HSCT (<6 months). There was no difference in the 6-month survival postrelapse in patients with isolated extramedullary relapse (44%) compared with combined extramedullary and bone marrow relapse (29%) or those with isolated bone marrow relapse (34%) (P = .8). Our data provide more insight into the disease behavior and treatment outcomes of ALL at relapse after HSCT against which future trials may be compared.

Cord blood transplantation (CBT) is curative for many patients with hematologic malignancies but is associated with delayed immune recovery and an increased risk of viral infections compared to human leukocyte antigen (HLA) matched bone marrow or peripheral blood progenitor cell transplantation. In this study we evaluated the significance of lymphocyte recovery in 125 consecutive patients with hematologic malignancies who underwent double-unit CBT (DUCBT) with an anti-thymocyte globulin-containing regimen at our institution. A subset of 65 patients were prospectively evaluated for recovery of T, natural killer (NK) and B cells and in 46 patients we also examined viral-specific T cell recovery against Adenovirus, Epstein-Barr virus, cytomegalovirus, BK virus, respiratory syncytial virus and Influenza antigen. Our results indicate that in recipients of DUCBT, the day 30 absolute lymphocyte count is highly predictive of non-relapse mortality (NRM) and overall survival (OS). Immune recovery post-DUCBT was characterized by prolonged CD8+ and CD4+ T lymphopenia associated with preferential expansion of B and NK cells. We also observed profound delays in quantitative and functional recovery of viral-specific CD4+ and CD8+ T-cell responses for the first year post-CBT. Taken together, our data support efforts aimed at optimizing viral-specific T cell recovery to improve outcomes post-CBT.

Nephropathy due to BK virus infection is an evolving challenge in patients undergoing hematopoietic stem cell transplantation. We hypothesized that BKV infection was a marker of Kidney Function Decline and a poor prognostic factor in HSCT recipients who experience this complication. In this retrospective study, we analyzed all patients who underwent their first allogeneic hematopoietic stem cell transplantation at our institution between 2004 and 2012. We evaluated the incidence of persistent kidney function decline, which was defined as a confirmed reduction in estimated glomerular filtration rate of at least 25% from baseline using the CKD-EPI equation. Cox proportional hazard regression was used to model the cause-specific hazard of kidney function decline and Fine and Gray’s method was used to account for the competing risks of death. Among 2477 recipients of a first allogeneic hematopoietic stem cell transplantation, BK viruria was detected in 25% (n=629) and kidney function decline in 944 (38.1%). On multivariate analysis, after adjusting for age, sex, acute graft-versus-host disease, chronic graft versus host disease, preparative conditioning regimen, and graft source, BK viruria remained a significant risk factor for kidney function decline (P <0.001). In addition, patients with BKV infection and kidney function decline experienced worse overall survival. Post-allogeneic hematopoietic stem cell transplantation, BKV infection was strongly and independently associated with subsequent kidney function decline and worse patient survival after HSCT.

For patients with ALL who relapse following allo-SCT, only a second SCT provides a realistic chance for long-term disease remission. We retrospectively analyzed the outcomes of 31 patients with relapsed ALL after a prior allo-SCT, who received a second SCT (SCT2) at our center. With a median follow-up of 3 years, 1-and 3-year PFS was 23 and 11% and 1-and 3 year OS rates were 23 and 11%. Twelve patients (39%) were transplanted with active disease, of whom 75% attained a CR. We found a significant relationship between the time to treatment failure following first allograft (SCT1) and PFS following SCT2 (P ¼ 0.02, hazard ratio ¼ 0.93/month). In summary, a second transplant remains a potential treatment option for achieving response in a highly refractory patient population. While long-term survival is limited, a significant proportion of patients remains disease-free for up to 1 year following SCT2, providing a window of time to administer preventive interventions. Notably, our four long-term survivors received novel therapies with their second transplant underscoring the need for a fundamental change in the methods for SCT2 to improve outcome.