Excellent outcome of allogeneic bone marrow transplantation for Fanconi anemia using fludarabine-based reduced-intensity conditioning regimen

Fanconi anemia (FA) is a disorder characterized by developmental anomalies, bone marrow failure and a predisposition to malignancy. It has recently been shown that hematopoietic stem cell transplantation using fludarabine (FLU)-based reduced-intensity conditioning is an efficient and quite safe therapeutic modality. We retrospectively analyzed the outcome of bone marrow transplantation (BMT) in eight patients with FA performed in two institutes between 2001 and 2011. There were seven females and one male with a median age at diagnosis = 4.5 years (range 2-12 years). The constitutional characteristics associated with FA, such as developmental anomalies, short stature and skin pigmentation, were absent in three of the patients. One patient showed myelodysplastic features at the time of BMT. All patients received BMT using FLU, cyclophosphamide (CY) and rabbit anti-thymocyte globulin (ATG) either from a related donor (n = 4) or an unrelated donor (n = 4). Acute graft-versus-host disease (GVHD) of grade I developed in one patient, while chronic GVHD was not observed in any patient. All patients are alive and achieved hematopoietic recovery at a median follow-up of 72 months (range 4-117 months). BMT using FLU/low-dose CY/ATG -based regimens regardless to the donor is a beneficial therapeutic approach for FA patients.     

Fludarabine, cyclophosphamide and horse antithymocyte globulin conditioning regimen for allogeneic peripheral blood stem cell transplantation performed in non-HEPA filter rooms for multiply transfused patients with severe aplastic anemia

Multiply transfused patients of severe aplastic anemia are at increased risk of graft rejection. Five such patients underwent peripheral blood stem cell transplantation from HLA-identical siblings with a fludarabine-based protocol. The conditioning consisted of fludarabine 30 mg/m(2)/day x 6 days, cyclophosphamide 60 mg/kg/day x 2 days and horse antithymocyte globulin (ATG) x 4 days. Two different ATG preparations were used: ATGAM (dose 30 mg/kg/day x 4 days) or Thymogam (dose 40 mg/kg/day x 4 days). Engraftment: median time to absolute neutrophil count (ANC) >0.5 x 10(9)/l was 11 days (range: 8-17) and median time to platelet count >20 x 10(9)/l was 11 days (range: 9-17). At a median follow-up of 171 days (range: 47-389), there has been no graft rejection and all patients are in complete remission. Acute GVHD (grade 1) occurred in one patient only. Chronic GVHD developed in two patients (extensive in one and limited in another). The transplants were performed in non-HEPA filter rooms. In only one patient, systemic antifungal therapy (voriconazole) was used. The use of Thymogam brand of ATG for conditioning is being reported for the first time. Our experience suggests that this fludarabine-based protocol allows rapid sustained engraftment in high-risk patients without significant immediate toxicity.     

A novel reduced-intensity stem cell transplant regimen for nonmalignant disorders

Bone marrow transplantation (BMT) benefits nonmalignant diseases but is limited by regimen-related toxicity, graft-versus-host disease (GVHD), donor availability, and graft rejection (GR). To overcome some of these barriers, we developed a new conditioning strategy for these patients. In total, 16 patients received Campath-1H (33/48 mg; days -21 to -19), fludarabine (150 mg/m(2); days -8 to -4), melphalan (140/70 mg/m(2); day -3), and transplant using related/unrelated stem cells. GVHD prophylaxis included cyclosporine/methylprednisolone for cord cells. Other recipients also received methotrexate. Risk factors for GR included multiple transfusions (6), low stem cell numbers (1), and immunologic/metabolic disorders (3). Donor engraftment was present in 14/16 recipients. Neutrophils (ANC>0.5 x 10(9)/l) and platelets (>50 x 10(9)/l) engrafted at a median of 13 and 24 days. Two patients died of Pseudomonas sepsis prior to engraftment, one of CMV disease, and another of intracranial hemorrhage. With median follow-up of 281 days (78-907), 12/16 are stable/improved, or cured. Acute GVHD was absent (n=10) or mild and transient (grade1-2 skin) (n=4). There was no chronic GVHD. Toxicities were predominantly early infections within 100 days, and correlated with lymphopenia (CD4+ T and B cells). Stable engraftment and low incidence of significant GVHD, irrespective of age or stem cell source, make this reduced-intensity regimen attractive for nonmalignant disorders.     

High-dose melphalan and allogeneic peripheral blood stem cell transplantation for treatment of early relapse after allogeneic transplant

Patients with acute leukemias relapsing within 1 year of an allogeneic BMT have a poor prognosis. We studied the use of melphalan 180 mg/m2 followed by allogeneic peripheral blood stem cells (PBSC) as salvage treatment for patients relapsing after related (n = 7) or matched unrelated transplants (n = 3). Diagnoses were AML (n = 4), ALL (n = 3), biphenotypic acute leukemia (n = 2) and CML in blast crisis (n = 1). Eight patients were beyond first relapse and none were in remission. The median time from previous transplant to relapse was 146 days (range 66-206). The melphalan dose was 90 mg/m2 intravenously on days -4 and -3 with PBSC infusion on day 0. GVHD prophylaxis consisted of cyclosporine and methylprednisolone. The median time to an absolute neutrophil count >0.5 x 10(9)/l and to a platelet count >20 x 10(9)/l was 11 and 13 days, respectively. All engrafting patients (n = 8) had 100% donor cells. Two patients died before day 30, but no other grade 3 or 4 toxicity occurred. Acute GVHD grades II-III occurred in two subjects, and chronic GVHD in four. Seven patients achieved CR, but relapsed at a median of 116 days (range 56-614). Leukemia was the cause of death in eight patients. Median survival was 149 days (range 6-614). This treatment produced responses in the majority of this poor prognosis group. However, durable remissions were not observed, and new treatments to consolidate the responses achieved in this setting are needed. This regimen could be considered for short-term disease control to facilitate donor lymphocyte infusion-based immunotherapy or other measures to prevent disease recurrence.     

Related and unrelated nonmyeloablative hematopoietic stem cell transplantation for malignant diseases

Patients with advanced hematological malignancies ineligible for conventional myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) due to advanced age or medical contraindications were enrolled in multi-center study to investigate the safety and efficacy of nonmyeloablative HSCT using a 2 Gy total body irradi ation (TBI)-based regimen. A total of 192 patients (median age 55) were treated with HLA-matched sibling peripheral blood stem cell (PBSC) grafts, and 63 patients (median age 53) received a 10 of 10 HLA-antigen matched unrelated donor (URD) HSCT (PBSC graft, n = 48; marrow graft, n = 15). Diagnoses included multiple myeloma (n = 61), myelodysplastic syndrome (n = 55), chronic myeloid leukemia (n = 31), non-Hodgkin lymphoma (n = 31), acute myeloid leukemia (n = 28), chronic lymphocytic leukemia (n = 24), Hodgkin Disease (n = 14). The conditioning regimen was fludarabine 30 mg/m2/d x 3 days and 2 Gy TBI. Ninety-five related HSCT patients received 2 Gy TBI without fludarabine. Postgrafting immunosuppression was combined mycophenolate mofetil an cyclosporine. Transplants were well tolerated with a median of 0 days of hospitalization in the first 60 days for eligible patients. For related HSCT recipients, median follow-up was 289 (100-1,188) days. Nonfatal graft rejection occurred in 6.8%. Of those with sustained engraftment, graft-versus-host disease (GVHD) occurred in 49% (33% grade II, 11% grade III, 5% grade IV). Day-100 non-relapse mortality was 6%. Overall, 59% (114/192) of patients were alive. The relapse/disease progression mortality was 18%, and non-relapse mortality was 22%. The projecte 2-year survival and progression-free survival were 50% and 40%. For the URD HSCT recipients, median follow-up was 190 (100-468) days. Graft rejection occurred in 27% (17/63) of patients, mostly in recipients of marrow grafts (9/15). Acute GVHD occurred in 63% (50% grade II, 13% grade III) of 46 engrafted patients. Chronic GVHD requiring therapy occurred in 50% of patients. Of the 63 URD HSCT patients, 54% were alive, 37% in CR, 3% PR, and 14% with disease progression or relapse. Related and unrelated nonmyeloablative HSCT is feasible and potentially curative in patients with advanced hematological malignancies who have no other treatment options.     

Allogeneic transplantation using CD34+ selected peripheral blood progenitor cells combined with non‐mobilized donor T cells for refractory severe aplastic anaemia

Allogeneic haematopoietic stem cell transplantation is curative for severe aplastic anaemia (SAA ) unresponsive to immunosuppressive therapy. To reduce chronic graft‐versus‐host disease (GVHD ), which occurs more frequently after peripheral blood stem cell (PBSC ) transplantation compared to bone‐marrow transplantation (BMT ), and to prevent graft rejection, we developed a novel partial T‐cell depleted transplant that infuses high numbers of granulocyte colony‐stimulating factor‐mobilized CD 34⁺ selected PBSC s combined with a BMT ‐equivalent dose of non‐mobilized donor T‐cells. Fifteen patients with refractory SAA received cyclophosphamide, anti‐thymocyte globulin and fludarabine conditioning, and were transplanted with a median 8 × 10⁶ CD 34⁺ cells/kg and 2 × 10⁷ non‐mobilized CD 3⁺ T‐cells/kg from human leucocyte antigen‐matched sibling donors. All achieved sustained engraftment with only two developing acute and two developing chronic GVHD . With a 3·5‐year median follow‐up, 86% of patients survived and were transfusion‐independent. When compared to a retrospective cohort of 56 bone‐marrow failure patients that received the identical transplant preparative regimen and GVHD prophylaxis with the exception that the allograft contained unmanipulated PBSC s, partial T‐cell depleted transplant recipients had delayed donor T‐cell chimerism and relative reduction of 75% in the incidence of acute grade II ‐IV GVHD (13% vs. 52%; P  =  0·010) and of 82% in chronic GVHD (13% vs. 72%; P  =  0·0004). In multivariate analysis, partial T‐cell depleted transplants remained significantly associated with a reduced risk of GVHD . In conclusion, for patients with refractory SAA , this novel transplant strategy achieves excellent engraftment and survival when compared to unmanipulated PBSC transplants and dramatically reduces the incidence of both acute and chronic GVHD .     

Fludarabine, cyclophosphamide plus thymoglobulin conditioning regimen for unrelated bone marrow transplantation in severe aplastic anemia

Antithymocyte globulin (ATG) has been used in severe aplastic anemia (SAA) as a part of the conditioning regimen. Among the many kinds of ATG preparations, thymoglobulin had been found to be more effective in preventing GVHD and rejection of organ transplants. As the fludarabine-based conditioning regimens without total body irradiation have been reported to be promising for bone marrow transplantation (BMT) from alternative donors in SAA, thymoglobulin was added to fludarabine and cyclophosphamide conditioning to reduce GVHD and to allow good engraftment in unrelated BMT. Five patients underwent BMT with cyclophosphamide (50 mg/kg once daily i.v. on days -9, -8, -7 and -6), fludarabine (30 mg/m2 once daily i.v. on days -5, -4, -3 and -2) and thymoglobulin (2.5 mg/kg once daily i.v. on days -3, -2 and -1) from HLA-matched unrelated donors. Complete donor type hematologic recovery was achieved in all patients. No serious complication occurred during BMT. Only one patient developed grade I acute GVHD resolved spontaneously. Except for one who had rupture of hepatic adenoma 78 days after BMT, all the other four patients are still alive with median 566 days. Fludarabine, cyclophosphamide plus thymoglobulin conditioning allows for the promising results of good engraftment, tolerable toxicity and minimal GVHD.     

Non-total body irradiation containing preparative regimen in alternative donor bone marrow transplantation for severe aplastic anemia

Using non-total body irradiation (TBI) containing preparative regimens, 13 patients with severe aplastic anemia (SAA) were transplanted from an alternative donor in a single institute. In total, 12 donors were unrelated volunteers and one was an HLA one-locus mismatched sibling. Median time from diagnosis of SAA to bone marrow transplantation (BMT) was 10.1 months (range, 1.6-180.1). Nine patients had received immunosuppressive treatment with ATG before BMT, while four had not. Preparative regimens consisted of cyclophosphamide plus ATG in nine patients, cyclophosphamide plus fludarabine in two patients, and cyclophosphamide plus fludarabine plus ATG in two patients. All patients received non-T-cell depleted bone marrow from the donor. Cyclosporine plus methotrexate were given for GVHD prophylaxis. All patients engrafted on a median of day 21 (range, 15-27). Grade III-IV acute GVHD developed in three (23%) of 13 patients and extensive chronic GVHD in four (31%) of 12 evaluable patients. With a median follow-up duration of 1138 days (range, 118-1553), 10 patients are alive with durable engraftment showing 74.6% (95% confidence interval, 49.5-99.7%) of survival rate. Cause of the deaths was CNS bleeding in one and chronic GVHD in two. In conclusion, non-TBI containing preparative regimen could ensure durable engraftment in alternative donor BMT for SAA and showed promising results.     

Reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells from the same donor for relapsed leukemia after bone marrow transplantation

We report the clinical courses of two cases with relapsed acute lymphoblastic leukemia (ALL) after allogeneic bone marrow transplantation (BMT). After reinduction chemotherapy, the patients received reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells harvested from their previous BMT donors. The conditioning regimen used consisted of fludarabine and melphalan. Graft-versus-host disease (GVHD) prophylaxis was performed with low dose cyclosporin A (CsA, 1 mg/kg/day d.i.v.) on its own. The regimen related toxicity was minimal, and stable engraftment was achieved. Since acute GVHD had not developed by day 30, CsA was stopped abruptly in both cases. After CsA withdrawal, acute GVHD developed, and subsequent chronic GVHD. One of two cases is alive without any relapse of the leukemia 40 months after the peripheral blood stem cell transplantation (PBSCT). In the other case, ALL relapsed 15 months after the PBSCT, however, complete remission was again induced concomitantly with reactivated GVHD. In both these cases, the results suggest that using PBSC as a stem cell source and abrupt cessation of GVHD prophylaxis provided a potent graft-versus-leukemia effect.     

Dose-reduced conditioning for allogeneic blood stem cell transplantation: durable engraftment without antithymocyte globulin

Between February 1998 and October 1999, 24 patients with advanced leukemia, lymphoma or solid tumors received G-CSF mobilized peripheral blood stem cells (PBSC) from HLA-matched sibling donors after dose-reduced conditioning therapy. Only patients with reduced performance status or major infectious complications, not eligible for standard transplant procedures, were included. The 5-day conditioning therapy consisted of 3.3 mg/kg intravenous busulphan x 2 days and 30 mg/m2 fludarabine x 5 days. GVHD prophylaxis was performed with either CsA alone (n = 5), CsA combined with short course methotrexate (n = 5) or mycophenolate mofetil (n = 14). The day 100 survival was 95.2% for the whole group. All patients engrafted after a median of 15 days (range, 11-19) and 12.5 days (range, 10-19) for neutrophils and platelets, respectively. The median time to a neutrophil count of <0.5 x 109/l was 7 days (range, 2 to 12). Acute GVHD >I was observed in six patients, whereas eight patients have signs of chronic GVHD. The prospective 12 month overall survival with a median follow-up of 7 months is 63%. Relapse of disease and toxicity associated with chronic GVHD were the main causes of death. The treatment-related mortality was 12.5%. Dose-reduced conditioning using intravenous busulphan and fludarabine allows stable engraftment without ATG in related transplants and leads to a reduction of transplant-related mortality.     

Additional stem cell therapy for graft failure after allogeneic bone marrow transplantation

In this study we retrospectively evaluated the effect and outcome of a boost dose of donor stem cells without additional chemotherapy or total body irradiation. Between March 1983 and August 1999, 20 of 788 (2.5%) patients receiving allogeneic bone marrow transplantation (BMT) were treated with an additional boost dose of donor cells. The reasons for the use of the boost treatment were primary graft failure (early rejection; n = 7), secondary graft failure including late rejection (n = 10), refractory pure red cell aplasia caused by the remaining recipient cells producing anti-erythrocyte antibodies (n = 2), and donor lymphocyte infusion induced pancytopenia (n = 1). The patients were aged from 17 to 48 years (median age 31 years). The underlying diseases of the patients were severe aplastic anemia in 12 patients, acute myelogenous leukemia in 3, acute lymphocytic leukemia in 3, and chronic myelogenous leukemia in 2. The donors were human leukocyte antigen-identical siblings in 18 cases, 1 mismatched related donor, and 1 unrelated donor. The cell source was bone marrow in 6 cases and peripheral blood progenitor cells in 14. The median interval between BMT and the boost treatment was 7 weeks (range 1-124). No conditioning regimen was given prior to the boost treatment for 11 patients, while 4 received total nodal irradiation (TNI) plus antithymocyte globulin (ATG), 3 ATG alone, and 2 TNI plus steroid. The median infused booster mononuclear cell dose was 2.55 x 10(8)/kg (range 0.28-37.0). Fifteen (75%) patients achieved a hematological recovery. After the boost treatment, 6 of 20 (30%) patients developed acute graft-versus-host disease (GVHD) > or = grade II, 3 of whom had had prior GVHD. Five (31.3%) of the evaluable 16 patients developed chronic GVHD. The GVHDs were easily controlled using immunosuppressive agents except in the case of 1 patient. Five patients died after the boost treatment; 2 within 30 days, 2 within 60 days, and 1 after 32 months. The causes of death were: 3 engraftment failures, 1 late rejection, and 1 infection following GVHD. With a median follow-up of 31.5 months (range 6-92), the Kaplan-Meier method estimated that the overall survival rate 1 and 3 years after the boost treatment was 80 and 71%, respectively. The survival of patients with primary graft failure was determined to be significantly lower compared to that of patients with secondary graft failure, using the log rank test (p = 0.0176). Disease category, stem cell source, conditioning prior to a boost treatment, and year of boost treatment did not have an influence on survival. We conclude that the reinfusion of donor stem cells is frequently successful in achieving engraftment with rare occurrence of fatal GVHD. Furthermore, relatively good long-term survival was demonstrated.     

Partial CD8+ T-cell depletion of allogeneic peripheral blood stem cell transplantation is insufficient to prevent graft-versus-host disease

Prior studies suggest that depletion of CD8+ T cells from donor bone marrow or donor lymphocyte infusions can reduce graft-versus-host disease (GVHD) without compromising graft-versus-leukemia. We explored CD8 depletion in patients undergoing matched related donor (MRD, n=25) and unrelated donor (URD, n=16) peripheral blood stem cell transplantation following myeloablative conditioning with cyclophosphamide (60 mg/kg/day i.v. x 2) and total body irradiation (200 cGy x 7 fractions). Ex vivo incubation of mobilized donor peripheral blood cells with anti-CD8 antibody coated high-density microparticles removed 99% of CD8+ cells. The median number of CD8+ cells infused was 3.9 x 10(5) cells/kg (2.2 x 10(5) in MRD, and 8.1 x 10(5) in URD patients). Post transplant immune suppression included tacrolimus in the MRD cohort, and tacrolimus plus mini-methotrexate (5 mg/m2 days +1, 3, 6, 11) in the URD cohort. All 41 patients engrafted. Grade 2-4 acute GVHD incidence was 61% (44% MRD, 88% URD). Chronic GVHD incidence was 50% (48% MRD, 55% URD). Relapse incidence was 4.9%. Estimated event-free and overall survival rates were 65 and 63%, respectively, at 1 year and 56 and 57%, respectively, at 2 years. There was no correlation between CD8+ number and GVHD or survival. A 2-log depletion of CD8+ cells from PBSC is insufficient to prevent GVHD.     

Successful HSCT using nonradiotherapy-based conditioning regimens and alternative donors in patients with Fanconi anaemia--experience in a single UK centre

Seven children with Fanconi anaemia (FA) (five female, two male), who had not undergone transformation, received nine haemopoietic stem cell transplantation (HSCT) between 2000 and 2004. Conditioning regimen was: fludarabine 25-30 mg/m2/day for 5 days, antilymphocyte globulin 12.5 mg/kg/day for 3 days and cyclophosphamide 5-7.5 mg/kg/day for 4 days. Radiation was not used. One male patient who had multiple HSCT and one female who was retransplanted, received slightly different conditioning regimens. Four patients received fully matched unrelated umbilical cord blood (UCB), two matched unrelated peripheral blood stem cell (PBSC) grafts, and three haploidentical T-cell-depleted (TCD) PBSC grafts. None of the patients had any significant conditioning-related toxicity or severe infections. All engrafted within 2-3 weeks. One patient rejected her first HSCT after 10 weeks and had a second successful transplant from the same donor. One male patient rejected his TCD haploidentical HSCT from his mother, and subsequently had a successful fully matched unrelated UCB transplant. Rejection rate was 22%. Acute and chronic graft-versus-host disease (GVHD) was seen in 77 and 22% patients. In all, 57% patients developed autoimmune complications, all of which have resolved. All patients are well with stable or full donor chimerism after a median follow-up of 37 months (range 13-54).     

Transplantation of allogeneic CD34+ peripheral blood stem cells in patients with advanced hematologic malignancy

Sixteen patients with advanced hematologic malignancies were transplanted with HLA-identical allogeneic peripheral blood stem cells (PBSCs) that were selected for CD34+ cells by an avidin-biotin immunoadsorption technique. The median age of patients was 48 years (range, 37 to 67). Patients received 12.0 or 13.2 Gy of total body irradiation followed by 120 mg/kg of cyclophosphamide. Normal donors received 16 mg/kg of granulocyte-colony stimulating factor on days 1 to 6 followed by PBSC harvests on days 4 to 7. PBSC harvests were processed each day on a single avidin-blotin column containing an antibody to the CD34 antigen and processed cells were infused without cryopreservation daily for 4 consecutive days. Prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine alone for 5 patients and CSA plus methotrexate for 11 patients. A median of 18.64 (6.74 to 34.97) x 10(8) CD34+ cells/kg patient body weight were collected from each donor. A median of 8.96 (2.62 to 17.34) x 10(8) CD34+ cells/kg patient body weight were recovered after avidin-biotin adsorption which represented a median CD34+ cell yield of 53% (18% to 77%) with a median purity of 62% (34% to 82%). There was a reduction in CD3+ cells from a median of 557.26 (227.73 to 677.77) x 106/kg to 0.73 x 10(4)/kg (0.40 to 3.65), in CD4+ cells from 351.72 (194.47 to 520.11) x 10(6)/kg to 0.40 (0.15 to 1.03) x 10(4)/kg and in CD8+ cells from 169.74 (53.34 to 325.83) x 10(6)/ kg to 0.32 (0.12 to 2.71) x 10(4)/kg representing a median 2.8 (2.19 to 3.14) log reduction in T cells. One patient died of infection on day 3 posttransplant and was unevaluable for recovery of neutrophils. The median day to recovery of 500 neutrophils/mL was 15 (8 to 26) in the remaining 15 patients. Six of 16 patients falled to achieve a platelet count of 20,000/mL before death on days 3 to 97 of transplant-related complications. The median day to achieving platelets of 20,000 mL in the remaining 10 patients was 11 (7 to 31). Eight of 16 patients (50%) died between 3 and 97 days posttransplant, 7 of transplant-related causes, and 1 of progressive disease. Grade 2-4 acute GVHD occurred in 12 out of 14 (86%) and grades 3-4 in 6 out of 14 (43%) evaluable patients. Six of 8 evaluable patients developed clinical chronic GVHD and 1 developed subclinical chronic GVHD. Bone marrow and/or peripheral blood chimerism studies in 12 evaluable patients showed 97% to 100% donor type in 11 patients with 1 patient in relapse showing 40% donor cells 60 to 90 days posttransplant. Four of 16 patients (25%) are alive and disease-free 312 to 576 days after transplant. There were no episodes of graft failure or rejection. This study shows that allogeneic transplantation using CD34+ selected PBSC results in prompt and sustained engraftment. CD34+ selection, as employed in this preliminary study, however, resulted in an apparently higher rate of acute and chronic GVHD. However, The sample size is quite small and precludes a more definitive conclusion regarding GVHD.     

Feasibility and safety of peripheral blood stem cell transplantation from unrelated donors: results of a single-center study

We compared the outcomes in patients receiving unrelated peripheral blood stem cell transplants (PBSCT) with those receiving bone marrow transplants (BMT) in a matched pair analysis. Seventy-four patients with hematological malignancies with HLA-matched (77%) and mismatched (23%) donors were analyzed in this study. Thirty-four patients (45%) were considered as high risk patients. Sixty-eight patients received standard conditioning regimens with Bu/Cy or TBI/Cy. Six patients received an intensified conditioning regimen with the addition of etoposide, thiotepa or melphalan. GVHD prophylaxis consisted of prednisolone, cyclosporine and methotrexate. Groups were matched for patient, donor, transplant characteristics and HLA compatibility. Peripheral blood stem cell collection led to the collection of a higher number of CD34+ and CD3+ cells in comparison to bone marrow collection. Leukocyte engraftment in the PBSCT group occurred in 14 days (median; range 6-26 days) and in the BMT group in 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly. The incidence of grades II-lV acute GVHD in the group of HLA-identical patients was 35% in the PBSCT group and 25% in the BMT group (P < 0.33, log-rank). However, there was a significant difference (P < 0.05, log-rank) in incidence and time to onset of acute GVHD II-IV comparing all patients, including the 17 mismatched transplants. Disease-free survival was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days for PBSC and BMT transplants, respectively. In conclusion, our results indicate that allogeneic PBSCT led to significantly faster leukocyte engraftment but is associated with a higher incidence and more rapid onset of severe acute GVHD comparing all patients, including the 17 mismatched transplants. However, the incidence of severe acute GVHD in HLA-identical patients was not different between the PBSCT and BMT groups.     

Related and unrelated nonmyeloablative hematopoietic stem cell transplantation for malignant diseases

Patients with advanced hematological malignancies ineligible for conventional myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) due to advanced age or medical contraindications were enrolled in a multi-center study to investigate the safety and efficacy of nonmyeloablative HSCT using a 2 Gy total body irradiation (TBI)-based regimen. A total of 192 patients (median age 55) were treated with HLA-matched sibling peripheral blood stem cell (PBSC) grafts, and 63 patients (median age 53) received a 10 of 10 HLA-antigen matched unrelated donor (URD) HSCT (PBSC graft, n=48; marrow graft, n=15). Diagnoses included multiple myeloma (n=61), myelodysplastic syndrome (n=55), chronic myeloid leukemia (n=31), non-Hodgkin lymphoma (n=31), acute myeloid leukemia (n=28), chronic lymphocytic leukemia (n=24), Hodgkin Disease (n=14). The conditioning regimen was fludarabine 30 mg/m²/d × 3 days and 2 Gy TBI. Ninety-five related HSCT patients received 2 Gy TBI without fludarabine. Postgrafting immunosuppression was combined mycophenolate mofetil and cyclosporine. Transplants were well tolerated with a median of 0 days of hospitalization in the first 60 days for eligible patients. For related HSCT recipients, median follow-up was 289 (100–1188) days. Nonfatal graft rejection occurred in 6.8%. Of those with sustained engraftment, graft-versus-host disease (GVHD) occurred in 49% (33% grade II, 11% grade III, 5% grade IV). Day-100 non-relapse mortality was 6%. Overall, 59% (114/192) of patients were alive. The relapse/disease progression mortality was 18%, and non-relapse mortality was 22%. The projected 2-year survival and progression-free survival were 50% and 40%. For the URD HSCT recipients, median follow-up was 190 (100–468) days. Graft rejection occurred in 27% (17/63) of patients, mostly in recipients of marrow grafts (9/15). Acute GVHD occurred in 63% (50% grade II, 13% grade III) of 46 engrafted patients. Chronic GVHD requiring therapy occurred in 50% of patients. Of the 63 URD HSCT patients, 54% were alive, 37% in CR, 3% PR, and 14% with disease progression or relapse. Related and unrelated nonmyeloablative HSCT is feasible and potentially curative in patients with advanced hematological malignancies who have no other treatment options.     

Complete substitution of cyclophosphamide by fludarabine and ATG in a busulfan-based preparative regimen for children and adolescents with beta-thalassemia

Children and adolescents with homozygous beta-thalassemia can be cured by transplantation of normal stem cells after eradication of the thalassemic hematopoietic system. In an attempt to achieve durable engraftment and to minimize regimen-related toxicity (RRT), we have initiated a fludarabine-based pilot protocol not containing cyclophosphamide. Between 1999 and 2004, five children with beta-thalassemia major were enrolled. Median age at transplantation was 11.5 years (range 4-14 years). Three patients received conditioning with fludarabine (30 mg/m2/day x 6), oral busulfan (3.5 mg/kg/day x 4), and ATG rabbit Fresenius (10 mg/kg/day x 4). Two children received intravenous busulfan instead of oral busulfan at a dose of 2 x 1.4 mg/kg/day x 4 days. All children were transplanted with a fresh bone marrow graft from an HLA-identical sibling. Mean cell doses given were 3.7 x 10(8) nucleated cells/kg BW (range 2.4-6.2 x 10(8)/kg). Overall, 5/5 patients achieved donor engraftment and are alive and well. No GVHD exceeding grade I was observed, and 2/5 children maintained donor chimerism at 100%. One patient maintains mixed hematopoietic donor chimerism being between 94 and 97% nearly 5 years after transplant.     

The role of thiotepa in allogeneic bone marrow transplantation for genetic diseases.

Graft-versus-host disease (GVHD), graft rejection, disease recurrence and long-term toxicity remain significant obstacles to successful allogeneic bone marrow transplantation (BMT) in children with genetic diseases. In an attempt to improve results, we used a preparative regimen consisting of three alkylating agents, busulfan (BU), thiotepa (TTP) and cyclophosphamide (CY), for T cell-depleted allogeneic bone marrow transplantation instead of the conventional BU-CY protocol. The effect of this intensified regimen was investigated in 26 consecutive children with genetic diseases who underwent T cell-depleted BMT from HLA-identical siblings. Sixteen patients were males and 10 females, of median age 5 (0.2-14) years. The diseases included beta-thalassemia major, osteopetrosis, severe combined immunodeficiency, Wiskott-Aldrich syndrome, familial agranulocytosis, congenital idiopathic hemolytic anemia (CIHA), Gaucher's disease, Niemann-Pick disease, Hurler's syndrome, and adrenoleukodystrophy. The conditioning regimen consisted of BU 4 mg/kg x 4 days (-8 to -5), TTP 5 mg/kg x 2 days (-4 and -3), and CY 60 mg/kg x 2 days (-2 and -1). Engraftment was as expected, with WBC >1.0 x 10(9)/l at day +19 (10-33), ANC >0.5 x 10(9)/l at day +22 (10-56) and platelets >25 x 10(9)/l at day +32 (18-131). Transplant-related mortality was 19%. Overall survival and disease-free survival (DFS) at 60 months follow-up were both 77%. Our results with the BU-TTP-CY regimen followed by T cell-depleted BMT in genetic diseases may provide a basis for prospective comparison with the standard conditioning regimen of BU-CY in the management of children suffering from these conditions.     

A prospective study of G-CSF primed bone marrow as a stem-cell source for allogeneic bone marrow transplantation in children: a Pediatric Blood and Marrow Transplant Consortium (PBMTC) study

A prospective multicenter trial was conducted to evaluate the safety and feasibility of granulocyte colony-stimulating factor (G-CSF)-primed bone marrow (G-BM) in children receiving allogeneic bone marrow transplantation (BMT). A total of 42 children with a median age of 9.8 years (range, 0.8-17 years) were enrolled. Donors with median age of 9.2 years (range, 1.1-22 years) received 5 microg/kg per day of subcutaneous G-CSF for 5 consecutive days. BM was harvested on the fifth day. No donor experienced complications related to G-CSF administration or marrow har-vest. Median nucleated (NC) and CD34 cells infused was 6.7 x 10(8)/kg (range, 2.4-18.5 x 10(8)/kg) and 7.4 x 10(6)/kg (range, 2-27.6 x 10(6)/kg), respectively. Neutrophil and platelet engraftment was at a median of 19 days (range, 13-28 days) and 20 days (range, 9-44 days), respectively. A total of 13 (32%) patients developed grade 2 graft-versus-host disease (GVHD), and 5 (13%) of 40 evaluable patients developed chronic GVHD (3 limited and 2 extensive). Higher cell dose was not associated with increased risk of acute or chronic GVHD. Overall survival and event-free survival at 2 years were 81% and 69%, respectively. Collection of G-BM from pediatric donors is safe, and can result in high NC and CD34 cell doses that facilitate engraftment after myeloablative BMT without a discernable increase in the risk of GVHD.     

Comparison of outcomes after transplantation of peripheral blood stem cells versus bone marrow following an identical nonmyeloablative conditioning regimen

This is the first study to examine the outcomes in 54 patients with hematologic malignancies who received an HLA-matched related donor bone marrow (BM, n = 42) or GCSF-mobilized peripheral blood stem cells (PBSC, n = 12) following identical nonmyeloablative conditioning with the intention of induction of mixed chimerism (MC) followed by prophylactic donor leukocyte infusion (pDLI) to convert MC to full donor chimerism (FDC) and capture a graft-versus-tumor effect without clinical graft-versus-host disease (GVHD). Neutrophil and platelet recovery were faster and transfusion requirement was less in PBSC recipients (P < 0.05). A total of 48% of BMT recipients achieved FDC with a median conversion time of 84 days, including 13 following pDLI. In contrast, 83% (P = 0.04) in the PBSC group had spontaneous FDC at a median of 14 days, precluding the administration of pDLI. There was no significant difference in the incidences of acute or chronic GVHD, though the rates of chronic GVHD were considerably higher in PBSC group than in the BM group (6/7, 86% vs 10/24, 42%). CD4 and CD8 T-cell recovery was faster in PBSC recipients. In PBSC recipients, a higher number of CD34+ cells was associated with increased rates of severe, grade III-IV acute GVHD.