Hematopoietic stem cell transplantation for high-risk adult patients with severe aplastic anemia; reduction of graft failure by enhancing stem cell dose

BACKGROUND AND OBJECTIVES: The main causes of failure after allogeneic hematopoietic stem cell transplantation (HSCT) in patients with severe aplastic anemia (SAA) are graft-versus-host disease (GVHD), infection and graft failure, often exacerbated by large numbers of transfusions and prolonged disease duration before transplant. This study retrospectively analyzes the outcome and factors related to survival or graft failure in high-risk patients with SAA receiving HSCT in our institution. DESIGN AND METHODS: Between January 1995 and December 1999, 40 consecutive adult patients who were multi-transfused (more than 40 units of red blood cells +/- platelets) and/or had a 3 years or longer period prior to transplant were enrolled. Their median age was 27.5 years (range, 16 to 43) and 21 (52.5%) were women. All donors were human leukocyte antigen (HLA)-matched siblings. Before transplant, 29 patients (72.5%) received a course of antithymocyte globulin (ATG) and cyclosporin A (CsA). The median interval from diagnosis to transplant was 59 months (range, 2 to 216). The median number of transfusions was 115 units (range, 10 to 480). All patients received a conditioning regimen of cyclophosphamide, ATG, and procarbazine. Our patients received either bone marrow (BM) alone (n=20) or BM+peripheral blood stem cells (PBSC) (n=20) as a stem cell source. T-cells of PBSC were depleted using the CD34 enrichment method. GVHD prophylaxis consisted of CsA and short-term methotrexate. RESULTS: In the BM+PBSC group, neutrophil recovery to 0.5 x 10(9)/L and platelet recovery to 20 x 10(9)/L were achieved more rapidly than in the BM group (p=0.005 and 0.039, respectively). The incidences of graft failure, grade II to IV acute GVHD, and chronic GVHD were 22.5%, 12.8% and 23.1%, respectively. Graft failure occurred in 2 of 20 patients (10%) receiving BM+PBSC and in 7 of 20 (35%) receiving BM alone (p=0.069). Seven of 9 patients who had graft failure received a booster treatment and recovered normal marrow function. GVHD incidence was comparable between the BM+PBSC and BM groups. Six patients (15%) died from graft failure (n=2), interstitial pneumonia (n=2), cyclophosphamide-induced heart failure (n=1), and chronic GVHD followed by pneumonia (n=1). The Kaplan-Meier estimate of survival was 83.7% with a median follow-up duration of 40.5 months (range 8-67). In multivariate analysis only chronic GVHD adversely influenced survival (p=0.042). INTERPRETATION AND CONCLUSIONS: These results suggest that HSCT is an effective treatment for multi-transfused SAA patients with prolonged disease duration. It is highly possible that the infusion of a large number of stem cells leads to a reduction of graft failure and a faster speed of engraftment. Booster treatment is successful in achieving engraftment in patients with graft failure.     

Difference in kinetics of hematopoietic reconstitution between ALL and ANLL after autologous bone marrow transplantation with marrow treated in vitro with mafosfamide (ASTA Z 7557)

The kinetics of hematopoietic recovery after autologous bone marrow transplantation (ABMT) reflect the hematopoietic capacity of the infused marrow. In vitro treatment of marrow with high doses of mafosfamide (ASTA Z 7557) alters the hematopoietic regenerative capacity of the graft. Thirty-two patients with acute leukemia (12 acute lymphoblastic leukemia (ALL) and 20 acute non-lymphoblastic leukemia (ANLL] with 27 in complete remission and five in partial remission were consolidated with cyclophosphamide (60 mg/kg x 2) and total body irradiation (10 Gy), followed by reinfusion of autologous marrow treated in vitro with mafosfamide. The marrow of each patient had been incubated with the highest tolerable dose of mafosfamide, individually predetermined from a preincubation test. We report here that the kinetics of engraftment are strikingly different in ANLL and ALL patients. In the ANLL group recovery to 0.1% reticulocytes took a median of 20.5 days (range 14-32) versus 15 (11-28) in the ALL group; 33.5 days (18-45) versus 19 (15-30) for leukocytes to reach 1.0 x 10(9)/l; 35 (19-60) versus 20.5 (15-30) for neutrophils to reach 0.5 x 10(9)/l; 110+ (45-480+) versus 50 (23-90) for platelets to reach 50 x 10(9)/l (p less than 0.01 and p less than 0.05). Detection of granulocyte-macrophage progenitors (CFU-GM) regeneration in marrow aspirates post-ABMT was delayed in ANLL (p less than 0.05). Neither the nature of the previous induction therapy, nor the status of the blood or bone marrow at the time of collection (CFU-GM and erythroid burst-forming units/ml) nor the stem cell sensitivity to mafosfamide, nor the doses of progenitor cells infused could explain these differences. We interpreted these observations as suggesting that the engraftment potential has been more severely altered in ANLL than in ALL, which may reflect both the intensity of the in vitro treatment and the intrinsic fragility of the stem cell pool in ANLL.     

Factors affecting neutrophil and platelet reconstitution following T cell-depleted bone marrow transplantation: differential effects of growth factor type and role of CD34(+) cell dose

We have performed univariate and multivariate analysis to determine the factors that affect the kinetics of neutrophil and platelet recovery in 546 recipients of T cell-depleted (TCD) marrow allografts. All patients received marrow depleted of mature CD3(+) T cells by complement-mediated lysis using T(10)B(9)-1A3 (n = 489) or Muromonab-Orthoclone OKT3 (n = 57) monoclonal antibodies. Neutrophil engraftment to 0.5 x 10(9)/1 and platelet engraftment to 20 x 10(9)/l were assessed as endpoints. Factors significantly affecting neutrophil or platelet engraftment in the univariate analysis included patient age, T cell dose, anti-thymocyte globulin use, gender, diagnosis at transplant, CMV serostatus, HLA mismatch, CD34 cell dose (n = 249), and growth factor use and type. These variables were included in the multivariate Cox proportional hazards regression model. The results showed that a faster rate of neutrophil engraftment was independently associated with CD34(+) cell dose > or = 5 x 10(6)/kg and most strongly with growth factor administration. Faster platelet engraftment was associated with transplantation for chronic leukemia, CD34(+) cell dose > or = 2 x 10(6)/kg, an HLA matched related donor, and the absence of growth factor use. G-CSF had a higher relative risk (RR) of enhancing neutrophil engraftment than GM-CSF and significantly delayed platelet engraftment. The combined use of G-CSF + GM-CSF was similar to G-CSF alone. The enhancing effect of G-CSF for neutrophil recovery was most striking for patients who engrafted to 0.5 x 10(9)/1 at or before day 12 (RR = 9.5, P < 0.0001) compared to patients who received no growth factor. Conversely, the delaying effect of G-CSF on platelet engraftment was strongest for patients engrafting on or before day 25 (RR = 0.4, P = 0.0004). Of the independent variables affecting engraftment kinetics in recipients of TCD marrow allografts only growth factor, and to a limited extent, CD34(+) cell dose can be controlled by the clinician. A higher CD34(+) cell dose enhances the rate of both neutrophil and platelet engraftment whereas for G-CSF the benefits of myeloid growth factor use in enhancing neutrophil recovery may be partly offset by a delay in platelet engraftment.     

Supplemental peripheral blood stem cells to decrease marrow rejection in adult patients with severe aplastic anemia

Twenty-two multi-transfused patients with a long duration of severe aplastic anemia (SAA) received a transplant from an HLA-matched donor after cyclophosphamide (CY) plus antithymocyte globulin plus procarbazine using CD34(+) enriched blood stem cells + fresh marrow. Peripheral blood stem cells (PBSC) were collected on days 5 and 6 of G-CSF (10 microg/kg/day), and T cells were depleted using an immunoadsorption column (n = 15) or magnetic cell sorting (n = 7). Marrow harvesting was performed 48 hr after the last leukapheresis. Two patients (9.1%) that developed graft failure had a successful engraftment again using unpurged PBSC. Median time to neutrophils > or = 0.5 x 10(9)/l and platelets > or = 20 x 10(9)/l without platelet transfusions were 12 days and 17 days, respectively. Acute graft-versus-host disease (GVHD) grade II occurred in four of 22 patients. No patient developed grade III or IV acute GVHD. Four of the evaluable 21 patients had chronic GVHD. One patient developed extensive disease. Three patients (13.6%) died from CY-induced heart failure, extensive-type chronic GVHD, and sepsis of unknown cause. The Kaplan-Meier estimate of survival was 83.9% (95% CI, 70.1-95.2%) with a median follow-up duration of 33.5 (6-44) months. CD34(+)-enriched PBSC in combination with unmanipulated marrow seem to play a role in overcoming the sensitization to histocompatibility antigens without an apparent increase in GVHD. The stem cell component therapy may be feasible for the high-risk SAA adult patients.     

Importance of marrow dose on posttransplant outcome in acute leukemia: models derived from patients autografted with mafosfamide-purged marrow at a single institution

Several prospective randomized trials in acute myelocytic leukemia (AML) documented a lower relapse rate with autologous bone marrow transplantation (ABMT) than with conventional chemotherapy. However, they also identified some transplant difficulties, such as failure to collect sufficient numbers of stem cells, slow kinetics of engraftment, and a high transplant-related mortality that diminished or negated positive impact on overall survival. Data for ABMT are inconclusive in acute lymphocytic leukemia (ALL) in adults. We retrospectively analyzed patients with acute leukemia autografted with marrow purged with mafosfamide after January 1983 in our institution. The population comprised 229 consecutive patients; 165 with AML [123 in first remission (CR1), 32 in second remission (CR2)]; 61 with ALL (46 in CR1, 4 in CR2); and 3 with undifferentiated acute leukemia. All patients were autografted with marrow purged with mafosfamide. Mafosfamide was given at a constant dose of 50 microg/mL in 103 and adjusted individually to produce a CFU-GM LD 95 (5% residual CFU-GM post purging) in 126. The outcome was analyzed for correlation with patient characteristics, the disease including cytogenetics, and the graft itself. Prognostic factors identified by multivariate analysis were used to derive a prognostic classification. Patients receiving higher doses of marrow submitted to purging (>5.46 x 10(4) CFU-GM/kg) experienced a lower treatment-related mortality (RR = 0.11, p = 0.005) and a higher leukemia-free (RR = 0.5, p = 0.005) and overall survival (RR = 0.4, p = 0.001). Patients receiving <0.004% CFU-GM of marrow actually infused post purging had a lower relapse rate (RR = 0.51, p = 0.003). Modeling of prognostic groups identified good-, intermediate-, and poor-risk categories. Patients receiving a stem cell dose evaluated before purging of >5.46 x 10(4) CFU-GM/kg and doses actually infused post purging of < or =0.02 x 10(4)/kg had a treatment-related mortality of only 2+/-2%, a leukemia-free survival of 70%, and an overall survival of 77+/-7% at 10 years. In this study of autotransplantation for acute leukemia using mafosfamide-purged marrow, the stem cell dose used for purging and the intensity of purging were the most important factors predicting outcome.     

Bone marrow transplantation in Fanconi anemia using matched sibling donors

Eighteen patients with Fanconi anemia (FA) with evidence of bone marrow (BM) aplasia underwent allogenic BM transplants (BMT) from matched sibling donors (MSD). Median age at BMT was 7.6 years. Conditioning consisted of low-dose cyclophosphamide (CY; 5 mg/kg x 4 days) and thoracoabdominal irradiation (TAI; 400 cGy). Graft-versus-host disease (GVHD) prophylaxis included cyclosporin A and prednisone. In addition antithymocyte globulin (ATG) was administered in the pretransplant period to promote engraftment and in the posttransplant period for additional GVHD prophylaxis. Engraftment occurred rapidly (median, 12 days for an absolute neutrophil count > or = 0.5 x 10(9)/L; median, 22 days for platelet count > or = 50 x 10(9)/L). Seventeen patients have sustained engraftment and are transfusion-independent, with Lansky scores of 100% at median follow-up of 27 months. One patient developed graft failure 4 months after initial engraftment and required a second BM infusion. None of the patients developed acute GVHD; 3 patients (16%) developed chronic GVHD. BMT is a feasible option for FA patients having an MSD and should be performed at a young age and early in the course of the disease, before the development of complications. We believe the addition of ATG to the transplant regimen of low-dose CY, TAI, and cyclosporin was responsible for improvement in the survival of FA patients undergoing BMT. The regimen was well tolerated and was associated with a low incidence of complications including GVHD.     

Graft failure following bone marrow transplantation for severe aplastic anemia: risk factors and treatment results

Graft failure was analyzed in 625 patients receiving allogeneic bone marrow transplants from HLA-identical sibling donors as treatment for severe aplastic anemia. Sixty-eight (11%) had no or only transient engraftment. Second bone marrow transplants were successful in achieving extended survival in 16 of 27 patients with transient initial engraftment but in none of ten patients with no sign of engraftment after the first transplant. The major factors associated with a reduced risk of graft failure were use of radiation for pretransplant immunosuppression and use of cyclosporine rather than methotrexate or T- cell depletion of the donor bone marrow for prophylaxis against graft-v- host disease (GVHD). Among 266 patients prepared for transplantation with cyclophosphamide alone, the risk of graft failure was increased in patients who received previous transfusions and reduced in those who received corticosteroids for previous therapy. Neither cell dose nor administration of donor buffy coat cells affected the probability of engraftment. Although use of radiation in conditioning reduced graft failure, survival was not improved. Posttransplant treatment with cyclosporine and avoidance of pretransplant blood transfusions were associated with improved survival.     

Use of recombinant human granulocyte-macrophage colony-stimulating factor in graft failure after bone marrow transplantation

The effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was evaluated in 37 patients with marrow graft failure after allogeneic (n = 15), autologous (n = 21), or syngeneic (n = 1) bone marrow transplantation. rhGM-CSF was administered by 2-hour infusion at doses between 60 and 1,000 micrograms/m2/d for 14 or 21 days. At doses of less than 500 micrograms/m2, rhGM-CSF was well-tolerated and did not exacerbate graft-versus-host disease in allogeneic transplant recipients. No patient with myelogenous leukemia relapsed while receiving rhGM-CSF. Twenty-one patients reached an absolute neutrophil count (ANC) greater than or equal to 0.5 x 10(9)/L within 2 weeks of starting therapy while 16 did not. None of seven patients who received chemically purged autologous marrow grafts responded to rhGM-CSF. The survival rates of GM-CSF-treated patients were significantly better than those of a historical control group.     

Engraftment and survival after unrelated-donor bone marrow transplantation: a report from the national marrow donor program

We analyzed engraftment of unrelated-donor (URD) bone marrow in 5246 patients who received transplants facilitated by the National Marrow Donor Program between August 1991 and June 1999. Among patients surviving at least 28 days, 4% had primary graft failure (failure to achieve an absolute neutrophil count > 5 x 10(8)/L before death or second stem-cell infusion). Multivariate logistic regression analysis showed that engraftment was associated with marrow matched at HLA-A, HLA-B, and DRB1; higher cell dose; younger recipient; male recipient; and recipient from a non-African American ethnic group. More rapid myeloid engraftment was associated with marrow serologically matched at HLA-A and HLA-B, DRB1 match, higher cell dose (in non-T-cell-depleted cases), younger recipient, recipient seronegativity for cytomegalovirus (CMV), male donor, no methotrexate for graft-versus-host disease prophylaxis, and transplantation done in more recent years. A platelet count higher than 50 x 10(9)/L was achieved by 47% of patients by day 100. Conditional on survival to day 100, survival at 3 years was 61% in those with platelet engraftment at day 30, 58% in those with engraftment between day 30 and day 100, and 33% in those without engraftment at day 100 (P <.0001). Factors favoring platelet engraftment were higher cell dose, DRB1 allele match, recipient seronegativity for CMV, HLA-A and HLA-B serologically matched donor, and male donor. Secondary graft failure occurred in 10% of patients achieving initial engraftment, and 18% of those patients are alive. These data demonstrate that quality of engraftment is an important predictor of survival after URD bone marrow transplantation.     

Supernatant cell counts from long-term bone marrow culture correlate with the speed of engraftment following autologous bone marrow transplantation.

This study evaluates the relationship between bone marrow growth in a long-term bone marrow culture (LTBMC) system and speed of engraftment of the same marrow following autologous bone marrow transplantation (ABMT). Bone marrow from 21 patients transplanted with unmanipulated, non-cryopreserved autologous marrow was cultured. Samples from 21 normal donors were cultured to establish the normal supernatant cell count range. Supernatant counts from LTBMCs established from marrow taken from patients at the time of bone marrow harvest were compared with the time to neutrophil and platelet engraftment. Supernatant counts, particularly after 1 week in culture, showed close correlation with time to neutrophil and platelet engraftment following ABMT (r = 0.733, p less than 0.01; r = 0.735, p less than 0.01 respectively). Where supernatant cell counts were within the normal range rapid engraftment was predicted (neutrophils greater than 0.5 x 10(9)/l within 21 days, platelets greater than 50 x 10(9)/l within 28 days) and if supernatant counts were below this range, engraftment was predicted to be delayed. After 1 week in culture, the speed of neutrophil and platelet engraftment were correctly predicted in 19 and 18 cases respectively. Preliminary data suggest that LTBMC of marrow obtained 2-6 weeks before harvesting provides similar data, thus allowing the opportunity to intervene, for example with growth factors, in selected patients.     

Related umbilical cord blood transplantation in patients with thalassemia and sickle cell disease

Allogeneic bone marrow transplantation (BMT) from HLA-identical siblings is an accepted treatment for both thalassemia and sickle cell disease (SCD). However, it is associated with decided risk of both transplant-related mortality (TRM) and chronic graft-versus-host disease (GVHD). We analyzed 44 patients (median age, 5 years; range, 1-20 years) given an allogeneic related cord blood transplant for either thalassemia (n = 33) or SCD (n = 11). Thirty children were given cyclosporin A (CsA) alone as GVHD prophylaxis, 10 received CsA and methotrexate (MTX), and 4 patients received other combinations of immunosuppressive drugs. The median number of nucleated cells infused was 4.0 x 10(7)/kg (range, 1.2-10 x 10(7)/kg). No patient died and 36 of 44 children remain free of disease, with a median follow-up of 24 months (range, 4-76 months). Only one patient with SCD did not have sustained donor engraftment as compared with 7 of the 33 patients with thalassemia. Three of these 8 patients had sustained donor engraftment after BMT from the same donor. Four patients experienced grade 2 acute GVHD; only 2 of the 36 patients at risk developed limited chronic GVHD. The 2-year probability of event-free survival is 79% and 90% for patients with thalassemia and SCD, respectively. Use of MTX for GVHD prophylaxis was associated with a greater risk of treatment failure. Related CBT for hemoglobinopathies offers a good probability of success and is associated with a low risk of GVHD. Optimization of transplantation strategies could further improve these results.     

Reassessing the definition of myeloid engraftment after autotransplantation: it is not necessary to see 0.5 x 10(9)/l neutrophils on 3 consecutive days to define myeloid recovery

The time to myeloid recovery after autologous hematopoietic stem cell transplantation (HSCT) is usually defined as the first of 3 consecutive days with an absolute neutrophil count (ANC) of >or=0.5 x 10(9)/l (ANC500). Universal documentation of ANC500 for 3 consecutive days, historically required to ensure robust myeloid recovery, has become difficult with a trend towards early discharge and outpatient HSCT. We studied 90 autografted patients to see how frequently ANC declined after having reached >or=0.5 x 10(9)/l. ANC500 was documented on 2 and 3 consecutive days in 14 and 63 patients, respectively. ANC increased by a median of 213% from the 1st to the 2nd day (rise in 75 and unchanged in two), and by a median of 142% from the 2nd day to the 3rd (rise in 60, unchanged in one, and decline in two; higher than the 1st day in the latter three). The increase from the 1st to the 3rd day was 13-3433% (median, 557%). Thus, in all 63 patients, no decline below ANC500 was seen, and the first day with ANC500 was also the first of 3 consecutive days with ANC500. The remaining 13 patients had repeat counts 2-7 days after the 1st day with ANC500 documenting further increase in ANC with no evidence of failed engraftment. These data show that the first day with ANC500 is also consistently the first of 3 consecutive days with ANC500 in autografted patients. Therefore, the traditional definition of myeloid engraftment should be changed to consider the first day with ANC500 as the day of engraftment without necessarily documenting ANC500 on the subsequent 1-2 days. This simple change in definition has significant implications for how data are reported to transplant registries and how peer-review organizations such as the Foundation for the Accreditation of Hematopoietic Cell Therapy (FAHCT) define completeness of data.     

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.     

Functional dendritic cells are required for transfusion-induced sensitization in canine marrow graft recipients

Untransfused dogs given 9.2 Gy total-body irradiation and hematopoietic grafts from DLA-identical littermate donors uniformly achieve sustained engraftment, whereas dogs given three transfusions (Tx) of whole blood from the intended marrow donor 24, 17 and 10 days pretransplant uniformly reject their graft. Sensitization appears to be mediated by peripheral blood mononuclear cells and can be prevented by prior irradiation of the Tx product with UV light, known to inactivate leukocytes, in particular, cells with accessory function. In the present study we investigated which leukocyte population was responsible for Tx-induced sensitization and subsequent marrow graft rejection. Surprisingly, neither monocytes nor macrophages or dendritic cells induced sensitization, and all dogs so treated achieved engraftment; however, all four evaluable dogs transfused with UV- exposed blood to which small numbers of normal dendritic cells (12.5 x 10(3)/kg) were added rejected their marrow graft. Among five dogs given UV-exposed blood and normal monocytes (12.5 x 10(3)/kg) only one rejected its graft, and four achieved sustained engraftment. We conclude that donor dendritic cells are necessary, albeit not sufficient for in vivo sensitization. Sensitization is prevented by elimination or inactivation of dendritic cell.     

Individually determined dosing of filgrastim after autologous peripheral stem cell transplantation in patients with malignant lymphoma--results of a prospective multicentre controlled trial

OBJECTIVES: To explore the safety and effectiveness of the individually determined application granulocyte-colony stimulating factor (G-CSF) after autologous peripheral blood stem cell transplantation (ASCT). METHODS: The administration of G-CSF from day +5 (arm A) was compared in a randomised, controlled trial with delayed, individually determined administration (G-CSF started when WBC >or= 0.5 x 10(9)/L and ANC >or= 0.1 x 10(9)/L or at day +10; arm B), and with placebo (arm C). RESULTS: One hundred and six patients, median age 45 (range 21-64), all with malignant lymphoma treated with BEAM chemotherapy were analysed. A significant difference in the time to neutrophil engraftment and in the duration of neutropenia <0.5 x 10(9)/L and <1.0 x 10(9)/L was observed between the arms (P = 0.04-<0.0001) with a 1-d prolongation of the median durations in arm B in comparison with arm A but a 2-4-d prolongation in the placebo arm C in comparison with arm B. The median number and range of days to neutrophil engraftment >0.5 x 10(9)/L after graft re-infusion was 10 (9-14) in arm A; 11 (9-19) in arm B; and 14 (10-30) in arm C (P < 0.0001). Engraftment of platelets to >20 x 10(9)/L and >50 x 10(9)/L was significantly delayed in the arms using G-CSF in comparison with placebo (P = 0.04-0.002) without any increase in bleeding or in transfusion requirement. There was no difference in the incidence and duration of transplant-related complications and their treatment between the arms. CONCLUSIONS: Our study has confirmed the safety of individually determined administration of G-CSF. The optimal timing of G-CSF application after ASCT in patients with good-quality grafts is shortly before expected spontaneous engraftment.     

Analysis of factors predicting speed of hematologic recovery after transplantation with 4-hydroperoxycyclophosphamide-purged autologous bone marrow grafts

We previously described the predictive value of graft colony-forming units granulocyte macrophage (CFU-GM) content after 4-hydroperoxycyclophosphamide (4-HC) purging for the duration of aplasia after autologous bone marrow transplantation. Despite the uniform 4-HC concentration, we observed heterogeneity in CFU-GM survival and the kinetics of engraftment. We have now analysed patient and graft characteristics for 154 patients undergoing autologous transplantation with 4-HC purged grafts to further define this heterogeneity. Patients transplanted for the treatment of malignant lymphoma reached a peripheral blood granulocyte count of greater than 0.5 x 10(9)/l (median, 20 versus 40 days; p less than 0.001) and platelet transfusion independence (median, 30 versus 70 days; p less than 0.001) significantly faster than patients transplanted for acute non-lymphoblastic leukemia. Other diagnostic groups were intermediate. These differences were independent of graft CFU-GM content. Multiple other patient and graft factors including patient age, peripheral blood counts on day of harvest, and amounts of other hematopoietic progenitors also predicted the kinetics of engraftment in univariate and multivariate analysis. Cytomegalovirus infection during the aplastic period predicted a delay in granulocyte (p = 0.024) but not platelet recovery (p = 0.174). This analysis demonstrates that multiple patient, graft, and post-transplant factors predict the engraftment capacity of autografts, and the kinetics of engraftment with 4-HC purged grafts. The multiple predictive factors explain a significant portion of the variability in engraftment kinetics observed after transplantation with 4-HC purged autografts.     

Low-dose lenograstim is as effective as standard dose in shortening neutrophil engraftment time following myeloablative chemotherapy and peripheral blood progenitor cell rescue

Granulocyte colony-stimulating factor (G-CSF) is widely used following myeloablative chemotherapy (high-dose therapy; HDT) and peripheral blood progenitor cell rescue (PBPCR) to reduce neutrophil engraftment time. The dose and duration required to gain maximum clinical and economic benefit has not been fully investigated. This double blind placebo-controlled randomised trial was performed to determine whether short course low-dose or standard-dose Lenograstim (L) would influence recovery of haematopoiesis following HDT and PBPCR. Sixty-one patients were randomised between May 1999 and November 2004, to receive standard-dose lenograstim (263 microg/d), low-dose lenograstim (105 microg/d) or placebo injections. These commenced on day +5 following PBPCR and continued until neutrophil engraftment [absolute neutrophil count (ANC)] > or = 0.5 x 10(9)/l. Patients received standard supportive care until haemopoietic recovery. Both standard- and low-dose lenograstim resulted in a significantly shorter median time to neutrophil recovery (ANC > or = 0.1 x 10(9)/l:10.0 vs. 11.0 d, P = 0.025; ANC > or = 0.5 x 10(9)/l:11.0 vs. 14.0 d, P = 0.0002) compared with placebo. There was no significant difference in blood product support, antibiotic usage, documented infection, overall survival or relapse-free survival between the groups. Short course low-dose lenograstim is as effective as standard-dose in reducing neutrophil engraftment time following HDT and PBPCR.     

Influence of human leucocyte antigen disparity and graft lymphocytes on allogeneic engraftment and survival after umbilical cord blood transplant in adults

The dose of graft-nucleated cells and CD34(+) haematopoietic progenitor cells are predictors of allogeneic engraftment and survival in umbilical cord blood (UCB) recipients. In this single institution prospective phase II trial, flow cytometric analyses of CD34(+) progenitor and lymphocyte populations in unmodified single unit human leucocyte antigen (HLA)-disparate UCB grafts infused into 31 consecutive adults (median age 41 years, range 20-64) receiving myeloablative conditioning were compared with clinical outcomes. Median infused UCB graft-nucleated cells and CD34(+) dose was 2.2 x 10(7)/kg and 1.2 x 10(5)/kg respectively. Day to absolute neutrophil count >/=0.5 x 10(9)/l with full donor chimerism averaged 27 d (range 12-41). Univariate analyses demonstrated that UCB graft-infused cell doses of CD34(+) (P = 0.015), CD3(+) (P = 0.024) and CD34(+)HLADR(+)CD38(+) progenitors (P = 0.043) correlated with neutrophil engraftment. This same analysis did not demonstrate a correlation between CD34(+) (P = 0.11), CD3(+) (P = 0.28) or CD34(+)HLADR(+)CD38(+) (P = 0.108) cell dose and event-free survival (EFS). High-resolution matching for HLA-class II (DRB1) resulted in improved EFS (P = 0.02) and decreased risk for acute graft-versus-host disease (GVHD) (P = 0.004). Early mortality (prior to post-transplant day +28) occurred in three patients, while 26 patients achieved myeloid engraftment. These results suggest that UCB graft matching at DRB1 is an important risk factor for acute GVHD and survival, while higher UCB graft cell doses of CD34(+), committed CD34(+) progenitors and CD3(+) T cells favourably influence UCB allogeneic engraftment.     

Bone marrow transplantation from matched siblings in patients with fanconi anemia utilizing low-dose cyclophosphamide, thoracoabdominal radiation and antithymocyte globulin

Nineteen patients with Fanconi anemia (FA) and bone marrow failure underwent bone marrow transplantation (BMT) from matched siblings. Median age at BMT was 8.7 years. Conditioning consisted of low-dose cyclophosphamide (CY 5 mg/kg x 4 days) and thoracoabdominal irradiation (TAI 400 cGy). Graft-versus-host disease (GVHD) prophylaxis was cyclosporin A (CsA) in 13 patients and CsA plus methotrexate in 6 patients. Antithymocyte globulin (ATG) was added in the pretransplant as well as the post-transplant period. All patients received high-dose acyclovir from day 2 pre-BMT to day 28 post BMT, and intravenous immunoglobulins (IVIG), 500 mg/kg weekly from day 7 pre-BMT to day 90 post BMT. No fungal prophylaxis was given. All patients engrafted, (median, 14 days for an absolute neutrophil count > or =0.5 x 10(9)/l; median, 37 days for platelet count > or =20 x 10(9)/l). Fourteen (74%) patients are alive with sustained engraftment and are transfusion independent. Three (16.6%) patients developed acute GVHD; none developed chronic GVHD. Five (26%) patients developed invasive fungal infections, and two (10%) developed fatal CMV disease. We believe the addition of ATG may have contributed to the increased incidence of severe life-threatening fungal and viral infections in our series.     

Bone marrow graft engineering by counterflow centrifugal elutriation: results of a phase I-II clinical trial

In an attempt to reduce the incidence and severity of acute graft-versus-host disease (GVHD), we have decreased the number of bone marrow (BM) lymphocytes in the donor marrow graft before bone marrow transplantation (BMT) using counterflow centrifugal elutriation (CCE). In a phase I-II clinical trial, 23 patients received lymphocyte-depleted BM allografts from their HLA-identical, mixed lymphocyte culture (MLC)-nonreactive sibling donors. The patients entered in the study were deemed to be at high risk for treatment failure on the basis of age (greater than 30 years; median, 39 years) and the result of our skin explant assay predictive of acute GVHD. Patients predicted not to develop acute GVHD by this assay were excluded from this study. All patients received a standard lymphocyte dose of 0.5 x 10(6) morphologic lymphocytes per kilogram ideal body weight (IBW) in the marrow graft and were maintained on cyclosporine A (CsA) immunosuppression for 170 days after BMT. Prompt hematopoietic recovery occurred in 22 of 23 patients with a median time to an absolute neutrophil count (ANC) greater than or equal to 500/microL of 21 days. Donor cell engraftment was subsequently verified by cytogenetic and/or DNA analysis in all of 21 evaluable patients. No patient developed systemic acute GVHD. Only five (22%) developed cutaneous GVHD (clinical stage 1) that required steroid treatment, including one patient who failed to engraft. The median follow-up of the patients enrolled in this study is 14 months (range, 5 to 20 months). Actuarial survival 1 year after BMT is 83%. Thus, in two consecutive clinical trials using CCE to deplete donor BM of alloreactive lymphocytes (1.0 x 10(6) versus 0.5 x 10(6) lymphocytes/kg), we have demonstrated that the procedure does not interfere with BM engraftment and is effective in decreasing the incidence and severity of acute GVHD. Furthermore, comparison of these studies has revealed a differential dose response relationship between the number of graft lymphocytes, protection of engraftment, and induction of acute GVHD. Although there appears to be a modest relationship between lymphocyte dose and time to hematopoietic recovery, the 50% reduction in lymphocyte dose from that used in our previous trial resulted in a marked decrease in acute GVHD without compromising engraftment.