Successful second cord blood transplantation using fludarabine and cyclophosphamide as a preparative regimen for graft rejection following reduced-intensity cord blood transplantation

Alemtuzumab, Fludarabine, Low-Dose TBI, and Double Umbilical Cord Transplant for Primary Graft Failure in a Patient with Recurrent HLH

Graft failure occurs at relatively low frequency, but commonly in hemophagocytic lymphohistiocytosis (HLH), especially with umbilical cord blood transplant (UCBT). No standard approaches to management of graft failure exist. We present a challenging case of relapsed HLH following first UCBT with primary graft failure following second UCBT. We report a novel reduced intensity conditioning regimen of alemtuzumab, 4 Gy total body irradiation and fludarabine for salvage of primary graft failure followed by double UCBT. The reported patient successfully engrafted with 100% donor chimerism following salvage UCBT with no occurrence of acute or chronic graft-versus-host disease.

Successful early unmanipulated haploidentical transplantation with reduced-intensity conditioning for primary graft failure after cord blood transplantation in hematologic malignancy patients

Primary graft failure (pGF) is a frequent complication following cord blood transplantation (CBT). For those patients who will not experience autologous recovery, salvage transplantation should be performed as early as possible. However, standardized treatment protocols for pGF, such as the optimal stem cell source, preparative regimen and the ideal time for salvage transplantation, have yet to be determined. Therefore, we analyzed 17 hematologic malignancy patients who received unmanipulated haploidentical peripheral blood (PB) and BM transplantation with reduced-intensity conditioning (RIC) as a salvage therapy for pGF after CBT. The median interval between the two transplantations was 38 days. The RIC regimen for salvage transplantation consisted of fludarabine, antithymocyte globulin, CY and low-dose TBI. The neutrophil and plt engraftments were achieved in 14 (82.4%) and 13 (76.4%) patients, respectively. The cumulative incidences of grades II-IV and grades III-IV aGVHD were 35.3% and 17.6%, respectively. The cumulative incidence of chronic GVHD was 29.4%. After a median follow-up of 43 months, 10 of 17 patients remained alive in CR. The cumulative incidence of TRM at 180 days was 29.4%. The probability of 3-year OS and leukemia-free survival was 57.5%. Our results show that unmanipulated haploidentical PB and BM transplantation under a RIC regimen is an effective treatment for pGF after CBT.

Intravenous apoptotic cell infusion as a cell-based therapy toward improving hematopoietic cell transplantation outcome

Allogeneic hematopoietic cell transplantation (AHCT) is an efficient therapy for different malignant and nonmalignant hematological diseases. However, the use of this therapeutic approach is still limited by some severe toxic side effects, mainly graft-versus-host disease (GvHD). Today, the risk of fatal GvHD restrains the wider application of AHCT to many patients in need of an effective therapy for their high-risk hematologic malignancies. Thus, new strategies, including cell-based therapy approaches, are required. We propose to use intravenous donor apoptotic leukocyte infusion to improve AHCT outcome. In experimental AHCT models, we demonstrated that intravenous apoptotic leukocyte infusion, simultaneously with allogeneic bone marrow grafts, favors hematopoietic engraftment, prevents allo-immunization, and delays acute GvHD onset. Here, we review the different mechanisms and the potential beneficial effects associated with the immunomodulatory properties of apoptotic cells in the AHCT setting.

Unrelated cord blood transplantation in pediatric patients: a report from Saudi Arabia

In unrelated cord blood (UCB) transplantation, survival has been shown to correlate with the degree of HLA matching. Thus, to extend transplant access to different ethnic backgrounds, many western UCB transplantation banks now encourage donation from non-Caucasians. Until recently, Saudi Arabia did not have a national UCB bank. In this study we report our experience in UCB transplantation in children using units procured from western cord blood banks. A total of 97 children underwent unrelated UCB transplantation at King Faisal Specialist Hospital and Research Center (KFSHRC), of which 95 were of Arab ethnicity. A total of 30 patients had malignant disorders, 25 patients had non-malignant hematological disorders and 42 patients had inborn errors. Conditioning was according to disease, with six patients receiving reduced-intensity regimens. In all, 46 patients received one-Ag-mismatched units and 51 received two-Ag-mismatched units. Engraftment occurred in 93% of patients, the 100-TRM was 15%, acute GVHD developed in 20% of patients and chronic GVHD occurred in 9% of patients. The 5-year OS and EFS estimates were 52 and 43%, respectively. The search for UCB transplantation units for Saudi patients in western banks yielded reasonably compatible units for our patients; the results are consistent with published data. Our data are encouraging for UCB transplant programs in countries in which there are no national UCB transplantation banks.

Primary graft failure after umbilical cord blood transplant rescued by parental haplocompatible stem cell transplantation

AB Graft failure and aplasia are known complications of umbilical cord blood (UCB) hematopoietic stem cell transplantation (HSCT). In the absence of a second HSCT, graft failure is generally a fatal complication due to overwhelming infection. We describe 2 children with primary graft failure and life-threatening infections after UCB HSCT who were rescued by the use of related haplocompatible T-cell-depleted peripheral blood stem cell transplants. The rapid availability of haplocompatible donors and the brisk neutrophil recovery after haplocompatible peripheral blood stem cell transplant with high numbers of CD34+ cells make this an attractive rescue strategy for patients with graft failure after UCB HSCT.

Cord blood transplantation using minimum conditioning regimens for patients with hematologic malignancies complicated by severe infections

Patients with severe infections are thought to be ineligible for cord blood stem cell transplantation (CBT) because the conventional 5-6 day-conditioning regimens potentially makes them susceptible to fatal infections by the time neutrophil engraftment occurs. Two patients were treated with minimum conditioning regimens consisting of 30 mg/m(2) fludarabin (Flu) and 2 g/m(2) cyclophosphamide (CY) on day-1 and total body irradiation (TBI) of 2 or 4 Gy on day -1 or 0 followed by single unit CBT. The reasons for adopting such weak regimen were febrile neutropenia due to the rejection of the first cord blood (CB) graft given to a patient with follicular lymphoma resistant to chemotherapy and pulmonary aspergillosis in another patient with AML who relapsed after CBT. The AML patient received 40 mg/m(2) of melphalan on day-2 to reduce the leukemia burden. Both patients achieved 100% donor chimerism by day 19 and day 20 after CBT without an apparent exacerbation of the infections and remained in remission at 23 and 18 months after the CBT. These findings suggest that the 1-2 day regimens excluding antihuman thymocyte globulin may be sufficiently potent to ensure engraftment of CB in immunocompromised patients and safely administered even when patients are complicated by active infections.