G-CSF given after haematopoietic stem cell transplantation using HLA-identical sibling donors is associated to a higher incidence of acute GVHD II-IV

Clinical effects of granulocyte colony-stimulating factor administration and the timing of its initiation on allogeneic hematopoietic cell transplantation outcomes for myelodysplastic syndrome

Granulocyte colony-stimulating factor (G-CSF) accelerates neutrophil recovery after allogeneic hematopoietic cell transplantation (HCT). However, the optimal use of G-CSF and the timing of its initiation after allogeneic HCT for myelodysplastic syndrome (MDS) according to graft type have not been determined. This retrospective study aimed to investigate the effects of using G-CSF administration and the timing of its initiation on transplant outcomes in adult patients with MDS undergoing allogeneic HCT. Using Japanese registry data, we retrospectively investigated the effects of G-CSF administration and the timing of its initiation on transplant outcomes among 4140 adults with MDS after bone marrow transplantation (BMT), peripheral blood stem cell transplantation (PBSCT), or single-unit cord blood transplantation (CBT) between 2013 and 2022. Multivariate analysis showed that early (days 0 to 4) and late (days 5 to 10) G-CSF administration significantly accelerated neutrophil recovery compared with no G-CSF administration following BMT, PBSCT, and CBT, but there was no benefit of early G-CSF initiation for early neutrophilic recovery regardless of graft type. Late G-CSF initiation was significantly associated with a higher risk of overall chronic GVHD following PBSCT (hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.18 to 2.24; P = .002) and CBT (HR, 2.09; 95% CI, 1.21 to 3.60; P = .007) compared with no G-CSF administration. Late G-CSF initiation significantly improved OS compared with no G-CSF administration only following PBSCT (HR, 0.74; 95% CI, 0.58 to 0.94; P = .015). However, G-CSF administration and the timing of its initiation did not affect acute GVHD, relapse, or non-relapse mortality, irrespective of graft type. These results suggest that G-CSF administration significantly accelerated neutrophil recovery after BMT, PBSCT, and CBT, but increased risk of overall chronic GVHD after PBSCT and CBT. However, the effect of early and late G-CSF initiation on transplant outcomes needs further study in adult patients with MDS.

Impact of Granulocyte Colony-Stimulating Factor (G-CSF) on Clinical Outcomes in Allogeneic Hematopoietic Cell Transplantation: Does Speeding Up Neutrophil Engraftment Make a Difference?

Background

Despite decades of post-allogeneic hematopoietic cell transplantation (HCT) growth factor utilization, its role remains undefined, leading to ongoing debates and research. The theoretical impacts of growth factors have been challenged in numerous studies.

Methods

In this retrospective cohort study conducted at the Princess Margaret Cancer Centre, we analyzed the clinical outcomes of 509 patients who underwent allogeneic HCT between May 1, 2019, and May 31, 2022. This study aimed to assess the impact of granulocyte colony-stimulating factor (G-CSF) administration posttransplantation on neutrophil and platelet engraftment, incidence of bloodstream infections (BSIs), graft-versus-host disease, engraftment syndrome (ES), and survival metrics including overall survival, nonrelapse mortality, and graft-versus-host disease-free/relapse-free survival.

Results

Our findings indicate that G-CSF administration expedited neutrophil engraftment (16 versus 18 d, P = 0.009) and was associated with a decreased incidence of BSI (9.4% versus 31.3%, P = 0.014). However, this benefit was counterbalanced by a significant delay in platelet engraftment (21 versus 17 d, P < 0.001). Multivariate logistic regression analysis identified mismatched donors (odds ratio, 1.72; 95% confidence interval, 1.03-2.88; P = 0.038) and the duration of G-CSF therapy (odds ratio, 1.04; 95% confidence interval, 1.00-1.09; P = 0.038) as independent predictors for the development of ES. Despite these hematological impacts, there was no observed advantage in overall survival, nonrelapse mortality, or graft-versus-host disease-free/relapse-free survival among patients who received G-CSF compared with those who did not.

Conclusions

Although G-CSF post-HCT expedited neutrophil engraftment and reduced BSI risk, it did not result in a survival advantage. The association with ES necessitates careful consideration.

Post-transplant G-CSF impedes engraftment of gene-edited human hematopoietic stem cells by exacerbating p53-mediated DNA damage response

Granulocyte-colony-stimulating factor (G-CSF) is commonly used to accelerate recovery from neutropenia following chemotherapy and autologous transplantation of hematopoietic stem and progenitor cells (HSPCs) for malignant disorders. However, its utility after ex vivo gene therapy in human HSPCs remains unexplored. We show that administering G-CSF from day 1 to 14 post-transplant impedes engraftment of CRISPR-Cas9 gene-edited human HSPCs in murine xenograft models. G-CSF affects gene-edited HSPCs through a cell-intrinsic mechanism, causing proliferative stress and amplifying the early p53-mediated DNA damage response triggered by Cas9-mediated DNA double-strand breaks. This underscores a threshold mechanism where p53 activation must reach a critical level to impair cellular function. Transiently inhibiting p53 or delaying the initiation of G-CSF treatment to day 5 post-transplant attenuates its negative impact on gene-edited HSPCs. The potential for increased HSPC toxicity associated with post-transplant G-CSF administration in CRISPR-Cas9 autologous HSPC gene therapy warrants consideration in clinical trials.

Different impacts of granulocyte colony-stimulating factor administration on allogeneic hematopoietic cell transplant outcomes for adult acute myeloid leukemia according to graft type

We retrospectively evaluated the impacts of using granulocyte colony-stimulating factor (G-CSF) and its timing on posttransplant outcomes for 9766 adults with acute myeloid leukemia (AML) between 2013 and 2022 using a Japanese database. We separately evaluated three distinct cohorts based on graft type: 3248 received bone marrow transplantation (BMT), 3066 received peripheral blood stem cell transplantation (PBSCT), and 3452 received single-unit cord blood transplantation (CBT). Multivariate analysis showed that G-CSF administration significantly accelerated neutrophil recovery after BMT, PBSCT, and CBT. However, it was associated with a higher risk of grades II-IV acute graft-versus-host disease (GVHD) across all graft types. Moreover, an increased incidence of overall chronic GVHD was observed with G-CSF administration in BMT and CBT patients, but not in PBSCT patients. G-CSF administration significantly improved overall survival (OS) and leukemia-free survival (LFS) only following CBT. Regarding the timing of G-CSF, in comparison with late initiation of G-CSF (Days 5-10), early initiation (Days 0-4) did not provide benefits for hematopoietic recovery regardless of graft type. In contrast, late initiation was significantly associated with a lower risk of grades II-IV acute GVHD and better OS and LFS in CBT patients. These data demonstrated that G-CSF administration accelerated neutrophil recovery and increased the risk of grades II-IV acute GVHD across all graft types, but significantly improved survival outcomes but only following CBT. Therefore, routine use of G-CSF should be considered for CBT in adult patients with AML.

Safety and efficacy of G-CSF after allogeneic hematopoietic cell transplantation using post-transplant cyclophosphamide: clinical and in vitro examination of endothelial activation

Since 2021 the use of G-CSF was implemented in allo-HCT with PTCY-based prophylaxis with the aim of shortening the aplastic phase and reducing infectious complications. This study investigates the effectiveness of this change in protocol performed at our institution. One-hundred forty-six adults undergoing allo-HCT with PTCY-based prophylaxis were included, and among them, 58 (40%) received G-CSF. The median of days to neutrophil engraftment was shorter in the G-CSF group (15 vs. 20 days, p < 0.001). Patients receiving G-CSF had a lower incidence of day +30 bacterial bloodstream infections (BSI) than the rest (20.7% vs. 47.7%, p < 0.001). GVHD, SOS, and TA-TMA incidences were comparable between groups, and using G-CSF did not impact on survival. Endothelial activation was investigated using EASIX and by the measurement of soluble biomarkers in cryopreserved plasma samples obtained on days 0, +7, +14 and +21 of 39 consecutive patients (10 received G-CSF) included in the study. EASIX, VWF:Ag, sVCAM-1, sTNFRI, ST2, REG3α, TM and NETs medians values were comparable in patients receiving G-CSF and those who did not. Compared with allo-HCT performed without G-CSF, the addition of G-CSF to PTCY-based allo-HCT accelerated neutrophil engraftment contributing on decreasing BSI incidence, and without inducing additional endothelial activation.

The Effect of Granulocyte Colony-Stimulating Factor (G-CSF) on Early Complications and Graft-Versus-Host Disease (GVHD) in Allogeneic Stem Cell Transplantation (ASCT) Recipients

Objectives Granulocyte colony-stimulating factor (G-CSF) is commonly used to accelerate neutrophil recovery after allogeneic stem cell transplantation (ASCT) in most transplant centers. There was no consensus on the optimal use of G-CSF after ASCT. Although we use G-CSF to minimize morbidity and mortality, G-CSF can increase the risk of graft-versus-host disease (GVHD). In our study, we want to show the effect of prophylactic G-CSF on infection frequency, neutrophil and platelet engraftment, the duration of neutropenia, the development of GVHD, hospitalization time, and transplant-related mortality (TRM) after ASCT. Materials and methods One hundred (71 males and 29 females) patients who did not receive G-CSF and 100 (58 males and 42 females) patients who received prophylactic G-CSF were included in the study. Results Age, diagnosis, the time between diagnosis and transplantation, preparation regimen, donor type, and the number of infused cluster of differentiation (CD) 34+ cells were not different in both groups (p>0.05). The frequency of female patients was higher in the group receiving G-CSF. Febrile neutropenia was more frequent in patients who did not receive G-CSF. Neutrophil engraftment and platelet engraftment were detected longer in patients not receiving G-CSF. The frequency of veno-occlusive disease (VOD) and hyperacute, chronic, and acute GVHD was not different in both groups (p>0.05). One hundred-day TRM and five-year overall survival (OS) were similar in the two groups (p>0.05). Conclusions Our study supports that G-CSF usage does not cause an increase in the frequency of GVHD and has a positive effect on the process by accelerating myeloid engraftment. In light of the data in our study, we can say that the use of G-CSF should be investigated in a randomized controlled clinical trial.

Post-Transplant Administration of G-CSF Impedes Engraftment of Gene Edited Human Hematopoietic Stem Cells by Exacerbating the p53-Mediated DNA Damage Response

Granulocyte colony stimulating factor (G-CSF) is commonly used as adjunct treatment to hasten recovery from neutropenia following chemotherapy and autologous transplantation of hematopoietic stem and progenitor cells (HSPCs) for malignant disorders. However, the utility of G-CSF administration after ex vivo gene therapy procedures targeting human HSPCs has not been thoroughly evaluated. Here, we provide evidence that post-transplant administration of G-CSF impedes engraftment of CRISPR-Cas9 gene edited human HSPCs in xenograft models. G-CSF acts by exacerbating the p53-mediated DNA damage response triggered by Cas9- mediated DNA double-stranded breaks. Transient p53 inhibition in culture attenuates the negative impact of G-CSF on gene edited HSPC function. In contrast, post-transplant administration of G-CSF does not impair the repopulating properties of unmanipulated human HSPCs or HSPCs genetically engineered by transduction with lentiviral vectors. The potential for post-transplant G-CSF administration to aggravate HSPC toxicity associated with CRISPR-Cas9 gene editing should be considered in the design of ex vivo autologous HSPC gene editing clinical trials.

Day 4 vs. day 12 G-CSF administration following reduced intensity peripheral blood allogeneic stem cell transplant

INTRODUCTION

Granulocyte colony-stimulating factor (G-CSF) hastens neutrophil engraftment and reduces infections after allogeneic hematopoietic cell transplant (alloHCT), yet the optimal start date is unknown. Additionally, concurrent G-CSF and methotrexate for graft-vs-host disease (GVHD) prophylaxis may potentiate myelosuppression, and prolonged G-CSF is costly. Our institution changed from day + 4 to day + 12 G-CSF initiation following reduced intensity (RIC) alloHCT with methotrexate GVHD prophylaxis.

METHODS

We retrospectively compared day + 4 and day + 12 G-CSF initiation after RIC alloHCT from 2017-2021. The primary endpoint was the time to neutrophil engraftment. Secondary endpoints included length of stay (LOS) and the time to platelet engraftment as well as the incidence of infectious events, acute GVHD (aGVHD), and mucositis.

RESULTS

Thirty-two patients were included in each group with similar baseline characteristics. We observed faster neutrophil engraftment (median 12 vs. 15 days, p = 0.01) and platelet engraftment (median 13 vs. 15 days, p = 0.026) with day + 4 vs. day + 12 G-CSF initiation. Median LOS was 23 days (range, 19-32) with day + 4 initiation vs. 24 days (21-30) with day + 12 (p = 0.046). The incidence of culture-negative febrile neutropenia (p = 0.12), any grade aGVHD (p = 0.58), and grade 2-4 mucositis (p = 0.8) were similar between groups.

CONCLUSION

Compared to day + 4, day + 12 G-CSF initiation following RIC alloHCT had a longer time to neutrophil and platelet engraftment. Day + 12 initiation also resulted in longer LOS, which while statistically significant, was potentially of limited clinical significance. These findings are hypothesis generating.

Bone Marrow Harbors a Unique Population of Dendritic Cells with the Potential to Boost Neutrophil Formation upon Exposure to Fungal Antigen

Apart from controlling hematopoiesis, the bone marrow (BM) also serves as a secondary lymphoid organ, as it can induce naïve T cell priming by resident dendritic cells (DC). When analyzing DCs in murine BM, we uncovered that they are localized around sinusoids, can (cross)-present antigens, become activated upon intravenous LPS-injection, and for the most part belong to the cDC2 subtype which is associated with Th2/Th17 immunity. Gene-expression profiling revealed that BM-resident DCs are enriched for several c-type lectins, including Dectin-1, which can bind beta-glucans expressed on fungi and yeast. Indeed, DCs in BM were much more efficient in phagocytosis of both yeast-derived zymosan-particles and Aspergillus conidiae than their splenic counterparts, which was highly dependent on Dectin-1. DCs in human BM could also phagocytose zymosan, which was dependent on β1-integrins. Moreover, zymosan-stimulated BM-resident DCs enhanced the differentiation of hematopoietic stem and progenitor cells towards neutrophils, while also boosting the maintenance of these progenitors. Our findings signify an important role for BM DCs as translators between infection and hematopoiesis, particularly in anti-fungal immunity. The ability of BM-resident DCs to boost neutrophil formation is relevant from a clinical perspective and contributes to our understanding of the increased susceptibility for fungal infections following BM damage.

G-CSF use post peripheral blood stem cell transplant is associated with faster neutrophil engraftment, shorter hospital stay and increased incidence of chronic GVHD

The use of G-CSF post allogeneic transplant has become a common practice to accelerate neutrophil engraftment. There is some controversy in its use. To further evaluate the effectiveness, we compared outcomes in patients who underwent PBSCT, either with or without the planned use of G-CSF post SCT. Among consecutive 162 patients from October 2012 to October 2014, 65 patients received G-CSF post-PBSCT, and 97 did not. More patients in G-CSF group received MAC (78% vs. 55%). Patients who received G-CSF had earlier neutrophil engraftment (median days 11 vs. 14) and shorter post-transplant hospital stay (median days 16 vs. 20, p = 0.001). G-CSF use was associated with a higher rate of extensive chronic GVHD (44.3% vs.61.5%, p = 0.027). G-CSF cost the equivalent of 0.25 hospital days but shortened the initial transplant admission by 4 days. Early cost-benefit may be later offset by the economic burden of chronic GVHD and associated complications.

The Effect of Granulocyte Colony-Stimulating Factor Use on Hospital Length of Stay after Allogeneic Hematopoietic Cell Transplantation: A Retrospective Multicenter Cohort Study

Granulocyte colony-stimulating factor (G-CSF) is administered after allogeneic hematopoietic cell transplantation (HCT) to aid neutrophil recovery. We compared the effect of empiric G-CSF administration on the duration of index inpatient hospitalization stay after HCT for patients aged ≥18 years with a hematologic malignancy. G-CSF was considered empiric if administered between day -3 and day +6 in relation to graft infusion. We studied 3562 HCTs (1487 HLA-matched sibling donor HCTs and 2075 HLA-matched unrelated donor HCTs) between 2007 and 2016. Three hundred and thirteen (21%) recipients of HLA-matched sibling donor HCT and 417 (20%) recipients of HLA-matched unrelated donor HCT received empiric G-CSF therapy. The effect of G-CSF therapy on the index hospitalization stay was examined in generalized linear models (GLMs) with adjustment for other patient, disease, and transplantation characteristics and acute graft-versus-host disease and infection post-transplantation. The duration of index hospitalization by treatment group did not differ for HLA-matched sibling donor HCT but was shorter with G-CSF for HLA-matched unrelated donor HCT (15 days versus 19 days; P < .001). Our GLMs confirmed shorter hospitalization with the use of G-CSF therapy for HLA-matched unrelated donor HCT (P = .01). G-CSF therapy was not associated with early survival for either donor type, and there was no benefit or disadvantage of giving G-CSF to promote neutrophil recovery.

Filgrastim following HLA-Identical Allogeneic Bone Marrow Transplantation: Long-Term Outcomes of a Randomized Trial

Human recombinant granulocyte colony stimulating factor reduces the duration of neutropenia following HLA-identical allogeneic bone marrow transplantation. However, its use remains controversial due to the risk of increasing the incidence of acute graft-versus-host disease (GVHD) and slower platelet recovery. To clarify these risks, we conducted a prospective randomized placebo-controlled trial of filgrastim 5 µg/kg/day i.v. from day 7 post-transplant until neutrophil recovery in 145 consecutive adults undergoing HLA-identical allogeneic bone marrow transplantation, with cyclosporine and methotrexate as GVHD prophylaxis. The primary endpoint was the incidence of acute GVHD; hematological recovery, nonrelapse mortality, and post-transplant complications were secondary endpoints. Filgrastim had no significant effect on the incidence of acute GVHD, platelet recovery, platelet transfusion requirements, chronic GVHD, or survival. Filgrastim accelerated granulocyte recovery significantly (with absolute neutrophil counts >.5 × 10⁹/L achieved after a median of 16 days versus 23 days for placebo; P < .0001), and reduced both early nonrelapse mortality (2.9% versus 10.5%; P = .042) and the duration of i.v. antibiotic therapy (18 days versus 26 days; P = .001) and hospitalization (27 versus 34 days; P = .017). In conclusion, in this setting, filgrastim reduced significantly the duration of neutropenia, i.v. antibiotic therapy, hospitalization, and early nonrelapse mortality, without increasing the risk of acute and chronic GVHD or relapse, or delaying platelet recovery.

Impact of fluoroquinolone prophylaxis on infectious-related outcomes after hematopoietic cell transplantation

BACKGROUND

Patients immediately post-hematopoietic cell transplantation are at high risk for bacteremia. Judicious prophylactic antimicrobial utilization must balance anticipated benefits (reduction infections) versus risk (bacterial resistance, Clostridium difficile) .

OBJECTIVE

To compare infectious outcomes (primary: incidence bacteremia; secondary: febrile neutropenia, C. difficile, susceptibility of bacteremia, time to discharge and 30-day mortality) between hematopoietic cell transplantation who received fluoroquinolone prophylaxis to those who did not.

METHODS

A local institutional review board-approved retrospective study was conducted on all hematopoietic cell transplantation patients ( n = 171) comparing those who received fluoroquinolone prophylaxis ( n = 105) to those who did not ( n = 66). Data included infectious outcomes and mortality for the first 30 days post-hematopoietic cell transplantation. Chi-squared was performed for categorical variables (GraphPad Software Inc., 2015). Secondary analysis compared outcomes within autologous and allogeneic sub-groups.

RESULTS

Bacteremia was significantly lower for the overall cohort receiving fluoroquinolone (median duration eight days) versus those without fluoroquinolone (15.2% vs. 31.8%; P < 0.01). No difference was seen in C. difficile infection ( P = 0.81) or 30-day mortality (2.9% vs. 4.5%; P = 0.67). In the autologous sub-group ( n = 115), bacteremia was significantly lower in the fluoroquinolone cohort (8.5% vs. 27.3%; P = 0.0069), while no differences were seen in C. difficile infection ( P = 1) or 30-day mortality ( P = 1). In the allogeneic sub-group ( n = 56), there was no difference between those with and without fluoroquinolone in bacteremia (29.4% vs. 40.9%; P = 0.4) or C. difficile ( P = 0.72); however, there was a trend toward improved 30-day mortality (2.9% vs. 9.1%; P = 0.55).

CONCLUSIONS

Fluoroquinolone prophylaxis reduces incidence of bacteremia in autologous hematopoietic cell transplantation without increasing C. difficile after hematopoietic cell transplantation.

Immunotherapy for infectious diseases in haematological immunocompromise

Opportunistic infections remain a major problem across a broad spectrum of immunocompromised haematological patient groups, with viruses, bacteria, fungi and protozoa all presenting significant challenges. Given the major difficulties in treating many of these infections with the currently available antimicrobial chemotherapeutic arsenal, and the rapid emergence of antimicrobial resistance amongst all of the microbial kingdoms, novel strategies that enable host control or elimination of infection are urgently required. Recently, major progress has been made in our understanding of host immunocompromise in the haematological patient. In addition, a wide range of novel immunomodulatory strategies for infectious diseases have been developed. Here we discuss the major and wide-ranging areas of progress that have been made for host-directed immunotherapies in the context of infectious diseases, with relevance to haematological immunocompromise.

Administration of G-CSF from day +6 post-allogeneic hematopoietic stem cell transplantation in children and adolescents accelerates neutrophil engraftment but does not appear to have an impact on cost savings

G-CSF post-allogeneic HSCT accelerates neutrophil engraftment, but evidence that it impacts on cost-related outcomes is lacking. We performed a retrospective child and adolescent single-center cohort study examining G-CSF administration from Day +6 of allogeneic HSCT vs. ad hoc G-CSF use where clinically indicated. Forty consecutive children and adolescents undergoing allogeneic HSCT were included. End-points were as follows: time to engraftment; incidence of acute and chronic GvHD; number of patients alive at Day +100; 180-day TRM; post-transplant days in hospital; and cost of antimicrobials, TPN, and G-CSF usage. Neutrophil engraftment occurred earlier in the group that received G-CSF from Day +6. There was no difference between groups in any of the other end-points with the following exception: the cost of GCSF was significantly higher in the D + 6 G-CSF group. However, median G-CSF cost in this group amounted to only €280. There was a trend towards reduced cost of antimicrobials in the D + 6 G-CSF group, although this did not reach significance (p = 0.13). The median cost per patient of antimicrobial agents between groups differed by €1116. This study demonstrated the administration of G-CSF on Day +6 in pediatric HSCT to be safe. A further study using a larger cohort of patients is warranted to ascertain its true clinico-economic value.

Recommendations for the Use of WBC Growth Factors: American Society of Clinical Oncology Clinical Practice Guideline Update

PURPOSE

To update the 2006 American Society of Clinical Oncology guideline on the use of hematopoietic colony-stimulating factors (CSFs).

METHODS

The American Society of Clinical Oncology convened an Update Committee and conducted a systematic review of randomized clinical trials, meta-analyses, and systematic reviews from October 2005 through September 2014. Guideline recommendations were based on the review of the evidence by the Update Committee.

RESULTS

Changes to previous recommendations include the addition of tbo-filgrastim and filgrastim-sndz, moderation of the recommendation regarding routine use of CSFs in older patients with diffuse aggressive lymphoma, and addition of recommendations against routine dose-dense chemotherapy in lymphoma and in favor of high-dose-intensity chemotherapy in urothelial cancer. The Update Committee did not address recommendations regarding use of CSFs in acute myeloid leukemia or myelodysplastic syndromes in adults.

RECOMMENDATIONS

Prophylactic use of CSFs to reduce the risk of febrile neutropenia is warranted when the risk of febrile neutropenia is approximately 20% or higher and no other equally effective and safe regimen that does not require CSFs is available. Primary prophylaxis is recommended for the prevention of febrile neutropenia in patients who are at high risk on the basis of age, medical history, disease characteristics, and myelotoxicity of the chemotherapy regimen. Dose-dense regimens that require CSFs should only be used within an appropriately designed clinical trial or if supported by convincing efficacy data. Current recommendations for the management of patients exposed to lethal doses of total-body radiotherapy, but not doses high enough to lead to certain death as a result of injury to other organs, include the prompt administration of CSFs.

Advances in haplo-identical stem cell transplantation in adults with high-risk hematological malignancies

Allogeneic bone marrow transplant is a life-saving procedure for adults and children that have high-risk or relapsed hematological malignancies. Incremental advances in the procedure, as well as expanded sources of donor hematopoietic cell grafts have significantly improved overall rates of success. Yet, the outcomes for patients for whom suitable donors cannot be found remain a significant limitation. These patients may benefit from a hematopoietic cell transplant wherein a relative donor is fully haplotype mismatched. Previously this procedure was limited by graft rejection, lethal graft-versus-host disease, and increased treatment-related toxicity. Recent approaches in haplo-identical transplantation have demonstrated significantly improved outcomes. Based on years of incremental pre-clinical research into this unique form of bone marrow transplant, a range of approaches have now been studied in patients in relatively large phase II trials that will be summarized in this review.

Recent advances on cellular therapies and immune modulators for graft-versus-host disease

The efficacy of allogeneic hematopoietic stem cell transplantation is counterbalanced by the occurrence of life-threatening immune-mediated complications, such as graft-versus-host disease (GVHD), a multistep disease which is reportedly fatal to approximately 15% of transplant recipients. It is now established that T-cell-dendritic cell interactions, T-cell activation, release of proinflammatory cytokines and T-cell trafficking partake in GVHD pathogenesis. This article will focus on the most recent strategies aimed at preventing/treating GVHD by manipulating components of the innate and adaptive immune response from both the donor and the host.

High incidence of severe acute graft-versus-host disease with tacrolimus and mycophenolate mofetil in a large cohort of related and unrelated allogeneic transplantation patients

Both acute and chronic graft-versus-host disease (GVHD) are major causes of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (AHSCT). The optimal pharmacological regimen for GVHD prophylaxis is unclear, but combinations of a calcineurin inhibitor (cyclosporin or tacrolimus [Tac]) and an antimetabolite (methotrexate or mycophenolate mofetil [MMF]) are typically used. We retrospectively evaluated the clinical outcomes of 414 consecutive patients who underwent AHSCT from sibling (SD) or unrelated donors (UD) with Tac/MMF combination, between January 2005 and August 2010. The median follow-up was 60 months. Less than one third of the patients received a reduced-intensity chemoregimen. The incidence of grades III and IV acute GVHD was 22.3% and 36.5% in SD and UD groups, respectively (P = .0007). The incidence of chronic GVHD was 47.1% and 52.7% in the SD and UD groups, respectively. Nonrelapse mortality (NRM) at 60 months was 33.3% and 46.5% in the SD and UD groups, respectively (P = .0016). The incidence of relapse was 22.4% for UD and 28.8% for SD. Five-year overall survival was 43% and 34% in the SD and UD groups, respectively (P = .0183). GVHD was the leading cause of death for the entire cohort. Multivariable analysis showed that 8/8 HLA match, patient's age < 60, and low-risk disease were associated with better survival. The use of Tac/MMF for GVHD prophylaxis was associated with a relatively high incidence of severe acute GVHD and NRM in AHSCT from sibling and unrelated donors.

Soluble human leukocyte antigen G molecule expression in allogeneic hematopoietic stem cell transplantation: good predictor of acute graft-versus-host disease

BACKGROUND

Graft-versus-host disease (GVHD) remains a main complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Human leukocyte antigen G (HLA-G) is a non-classical class I molecule exerting multiple immunoregulatory functions. The aim of this study was to explore the relationship between soluble HLA-G (sHLA-G) and GVHD after allo-HSCT.

METHODS

The sHLA-G levels were examined using enzyme-linked immunosorbent assay in patients with hematological malignancies (n = 106) before transplantation, on days +15 and +30 after transplantation, as well as healthy volunteers (n = 10).

RESULTS

The levels of sHLA-G5, sHLA-G6 and sHLA-G7 in patients on days +15 and +30 after transplantation were all significantly higher than those before transplantation (all p ≤ 0.001). The increased levels of sHLA-G5 on days +15 and +30 after transplantation were both significantly higher in patients with grade 0-I acute GVHD (aGVHD) compared to those with grade II-IV aGVHD (both p < 0.001). The increased levels of sHLA-G5 on days +15 and +30 after transplantation were both negatively correlated with the severity of aGVHD (both p < 0.001).

CONCLUSION

sHLA-G5 might be a predictor of the occurrence and severity of aGVHD, which may help to establish individual prophylaxis against aGVHD and improve the survival for patients after allo-HSCT.

Graft failure in the modern era of allogeneic hematopoietic SCT

Graft failure may contribute to increased morbidity and mortality after allogeneic hematopoietic SCT (allo-HSCT). Here, we present risk factors for graft failure in all first allo-HSCTs performed at our center from 1995 to mid-2010 (n=967). Graft failure was defined as >95% recipient cells any time after engraftment with no signs of relapse, or re-transplantation because of primary or secondary neutropenia (<0.5 × 10(9)/L) and/or thrombocytopenia (<30 × 10(9)/L). Fifty-four patients (5.6%) experienced graft failure. The majority were because of autologous reconstitution (n=43), and only a few patients underwent re-transplantation because of primary (n=6) or secondary (n=5) graft failures. In non-malignant disorders, graft failure had no effect on survival, whereas in malignant disease graft failure was associated with reduced 5-year survival (22 vs 53%, P<0.01). In multivariate analysis, ex vivo T-cell depletion (relative risk (RR) 8.82, P<0.001), HLA-mismatched grafts (RR 7.64, P<0.001), non-malignant disorders (RR 3.32, P<0.01) and reduced-intensity conditioning (RR 2.58, P<0.01) increased the risk for graft failure, whereas graft failures were prevented by total nucleated cell doses of ≥ 2.5 × 10(8)/kg (RR 0.36, P<0.01). In conclusion, graft failure was only associated with inferior survival in malignant disease. Non-malignant disorders, HLA match, conditioning intensity, immunosuppression regimen and cell dose all influenced graft failure risk.

A novel conditioning regimen improves outcomes in β-thalassemia major patients using unrelated donor peripheral blood stem cell transplantation

We used a novel NF-08-TM transplant protocol based on intravenous busulfan, cyclophosphamide, fludarabine, and thiotepa in 82 consecutive patients with β-thalassemia major (TM), including 52 with allogeneic peripheral blood stem cell transplantation (PBSCT) from unrelated donors (UDs) with well-matched human leukocyte antigens and 30 with hematopoietic stem cell transplantation (HSCT) from matched sibling donors (MSDs). The median age at transplantation was 6.0 years (range, 0.6-15.0 years), and the ratio of male-to-female patients was 56:26. The median follow-up time was 24 months (range, 12-39 months). The estimated 3-year overall survival and TM-free survival were 92.3% and 90.4% in the UD-PBSCT group and 90.0% and 83.3% in the MSD-HSCT group. The cumulative incidences of graft rejection and grades III-IV acute graft-versus-host disease were 1.9% and 9.6%, respectively, in the UD-PBSCT group and 6.9% and 3.6%, respectively, in the MSD-HSCT group. The cumulative incidence of transplant-related mortality was 7.7% in the UD-PBSCT group and 10.0% in the MSD-HSCT group. In conclusion, UD-PBSCTs using the well-tolerated NF-08-TM protocol show similar results to MSD-HSCTs and can be used to treat β-thalassemia patients in the absence of MSDs.

Growth factor-associated graft-versus-host disease and mortality 10 years after allogeneic bone marrow transplantation

This study analysed the effects of growth factor on outcome after haematopoietic stem-cell transplantation (HSCT) with >9 years follow-up. Of 1887 adult patients with acute leukaemia who received bone marrow from human leucocyte antigen (HLA)-identical siblings and were treated with myeloablative conditioning, 459 (24%) were treated with growth factor. Growth factor hastened engraftment of neutrophils (P < 0·0001), but reduced platelet counts (P = 0·0002). Graft-versus-host disease (GVHD)-free survival (no acute GVHD grade II-IV or chronic GVHD) at 10 years was 12 ± 2% (±SE) in the growth factor group, as opposed to 17 ± 2% in the controls [hazard ratio (HR) 0·81, P = 0·001]. Similar differences in GVHD-free survival were seen in patients with or without conditioning with total body irradiation (TBI). Non-relapse mortality (NRM) was higher in the growth factor group irrespective of whether or not TBI conditioning was included [HR = 1·48; 95% confidence interval (CI): 1·15-1·9; P = 0·002; HR = 1·59; 95% CI: 1·07-2·37; P = 0·02, respectively]. Both groups had similar probabilities of leukaemic relapse (HR = 0·96; 95% CI: 0·78-1·18; P = 0·71). Leukaemia-free survival (LFS) at 10 years was 35 ± 2% in those receiving growth factor prophylaxis, as opposed to 44 ± 1% in the controls (HR = 0·70; 95% CI: 0·60-0·82; P = 0·00001). Prophylaxis with growth factor increases the risk of GVHD, does not affect relapse, increases NRM and reduces LFS > 10 years after HSCT, regardless of conditioning with TBI.

Improved survival after allogeneic hematopoietic stem cell transplantation in recent years. A single-center study

We analyzed the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) over the past 2 decades. Between 1992 and 2009, 953 patients were treated with HSCT, mainly for a hematologic malignancy. They were divided according to 4 different time periods of treatment: 1992 to 1995, 1996 to 2000, 2001 to 2005, and 2006 to 2009. Over the years, many factors have changed considerably regarding patient age, diagnosis, disease stage, type of donor, stem cell source, genomic HLA typing, cell dose, type of conditioning, treatment of infections, use of granulocyte-colony stimulating factor (G-CSF), use of mesenchymal stem cells, use of cytotoxic T cells, and home care. When we compared the last period (2006-2009) with earlier periods, we found slower neutrophil engraftment, a higher incidence of acute graft-versus-host disease (aGVHD) of grades II-IV, and less chronic GVHD (cGHVD). The incidence of relapse was unchanged over the 4 periods (22%-25%). Overall survival (OS) and transplant-related mortality (TRM) improved significantly in the more recent periods, with the best results during the last period (2006-2009) and a 100-day TRM of 5.5%. This improvement was also apparent in a multivariate analysis. When correcting for differences between the 4 groups, the hazard ratio for mortality in the last period was 0.59 (95% confidence interval [CI]: 0.44-0.79; P < .001) and for TRM it was 0.63 (CI: 0.43-0.92; P = .02). This study shows that the combined efforts to improve outcome after HSCT have been very effective. Even though we now treat older patients with more advanced disease and use more alternative HLA nonidentical donors, OS and TRM have improved. The problem of relapse still has to be remedied. Thus, several different developments together have resulted in significantly lower TRM and improved survival after HSCT over the last few years.

HLA-matched sibling transplantation with G-CSF mobilized PBSCs and BM decreases GVHD in adult patients with severe aplastic anemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for severe aplastic anemia (SAA). However, graft failure and graft-versus-host disease (GVHD) are major causes of the early morbidity in Allo-HSCT.

METHODS

To reduce graft failure and GVHD, we treated fifteen patients with SAA using high- dose of HSCT with both G-CSF mobilized PB and BMSCs from HLA-identical siblings to treat patients with SAA.

RESULTS

All patients had successful bone marrow engraftment. Only one patient had late rejection. Median time to ANC greater than 0.5 × 10(9)/L and platelet counts greater than 20 × 10(9)/L was 12 and 16.5 days, respectively. No acute GVHD was observed. The incidence of chronic GVHD was 6.67%. The total three-year probability of disease-free survival was 79.8%.

CONCLUSION

HSCT with both G-CSF mobilized PB and BMSCs is a promising approach for heavily transfused and/or allo-immunized patients with SAA.

Granulocyte colony-stimulating factor induced acute and chronic graft-versus-host disease

BACKGROUND

A recent experimental study in mice shed new light on the controversy as to whether granulocyte colony-stimulating factor (G-CSF) increases graft-versus-host disease (GVHD). Total body irradiation and bone marrow were found to be prerequisites for acute GVHD. This study encouraged us to perform a retrospective clinical study.

METHODS

We compared 260 patients given G-CSF prophylaxis after allogeneic hematopoietic stem-cell transplantation with 205 controls transplanted between 1993 and 2003.

RESULTS

G-CSF hastened the engraftment of neutrophils, but that of platelets was delayed (P<0.0001). The proportion of acute GVHD of grades II to IV was 29% in the G-CSF group and 19% in the controls (P<0.01) and that of chronic GVHD was 54% and 43%, respectively (P=0.019). G-CSF increased acute and chronic GVHD in patients preferentially conditioned with chemotherapy. Unexpectedly, it exacerbated acute GVHD in recipients of peripheral blood stem cells and enhanced chronic GVHD in bone marrow recipients. A multivariable analysis showed that acute GVHD (hazards ratio=1.52, P=0.03) and chronic GVHD (hazards ratio=1.51, P=0.004) were associated with G-CSF. There was no significant difference between study groups regarding nonrelapse mortality, relapse, or survival.

CONCLUSION

G-CSF increased acute and chronic GVHD in patients treated with chemotherapy but did not affect relapse or survival.

Increased adenosine triphosphate production by peripheral blood CD4+ cells in patients with hematologic malignancies treated with stem cell mobilization agents

Hematopoietic stem cell (HSC) transplantation is an important therapeutic option for patients with hematologic malignancies. To explore the immunomodulatory effects of HSC mobilization agents, we studied the function and phenotype of CD4(+) T cells from 16 adult patients with hematologic malignancies undergoing HSC mobilization treatment for autologous transplantation. Immune cell function was determined using the Immuknow (Cylex) assay by measuring the amount of adenosine triphosphate (ATP) produced by CD4(+) cells from whole blood. ATP activity measured in G-CSF-treated patients was significantly higher than that measured in healthy individuals or "nonmobilized" patients. In patients treated with G-CSF, CD4(+) T cells were predominantly CD25(low)FOXP3(low), consistent with an activated phenotype. However, T-cell depletion did not abrogate ATP production in blood samples from G-CSF-treated patients, indicating that CD4(+) myeloid cells contributed to the increased ATP levels observed in these patients. There was a significant correlation between ATP activity and patient survival, suggesting that efficient activation of CD4(+) cells during mobilization treatment predicts a low risk of disease relapse. Monitoring immune cell reactivity using the Immuknow assay may assist in the clinical management of patients with hematologic malignancies and optimization of HSC mobilization protocols.

Immunotherapy by allogeneic stem cell transplantation

During the past three decades, allogeneic stem cell transplantation (ASCT) has developed from being an experimental therapy in patients with endstage leukemia into a well-established therapy in patients with a range of disorders of the immunohematopoietic system. Graft-versus-host disease (GVHD), acute or chronic, attacking host tissue is a major threat. However, donor immunocompetent T cells have a potent graft-versus-leukemia effect. A combination of calcineurin inhibitors and methotrexate is the standard therapy to prevent GVHD. Modulation of the immunosuppressive regimen may induce mild acute and mild chronic GVHD, reduce the risk of relapse, and improve long-term survival. Natural killer cells also play a role in this context. Killer cell immunoglobulin-like receptor incompatibility between recipient and donor may reduce the risk of relapse in patients with myeloid leukemia. Relapse of leukemia is a major cause of death after ASCT. Minimal residual disease and recipient leukemia lineage-specific chimerism are sensitive techniques for early detection of leukemic relapse. Donor lymphocyte infusions can enhance the antitumor effect, especially for patients with molecular relapse. The allogeneic graft-versus-cancer effect has been demonstrated in patients with metastatic breast, renal, colorectal, ovarian, prostatic, and pancreatic carcinoma. Mesenchymal stem cells have immunomodulatory properties and may be used for immunomodulation of GVHD and tissue repair. All things considered, the future looks promising for ASCT.

Sequential administration of sargramostim and filgrastim in pediatric allogeneic stem cell transplantation recipients undergoing myeloablative conditioning

G-CSF and GM-CSF both hasten myeloid engraftment post-MA-alloSCT; however, GM-CSF is earlier acting and less expensive. The objective was to evaluate efficacy/safety of sequential administration of GM-CSF followed by G-CSF in children post-MA-alloSCT. From January 2001 to June 2005, 31 children received 32 MA-alloSCT: mean age 6.65 yr; MRD BM or PBSC vs. related or unrelated UCB 11:21; malignant vs. non-malignant disorders 22:10. GM-CSF (250 microg/m(2) IV QD) began on day of stem cell infusion. GM-CSF was switched to G-CSF (10 microg/kg IV QD) when WBC >or= 300/mm(3) x 2 days. G-CSF continued until ANC >or= 2500/mm(3) x 2 days, then tapered to maintain ANC >or= 1000/mm(3). Median time to myeloid engraftment (ANC >or= 500/mm(3) x 3 days) was 17 days [13 days vs. 24 days, MRD BM/PBSC vs. UCB (p < 0.0001)], occurring at a median time of two days after switch to G-CSF. Clinically relevant adverse events were bone pain (n = 8) and large pleural effusion (n = 1). It was estimated that sequential GM-CSF/G-CSF was cost-effective compared with G-CSF alone [cost-savings of $1311/patient ($41,952/study), 2007 Red Book Average Wholesale Price]. In summary, it was demonstrated that sequential administration of GM-CSF/G-CSF post-MA-alloSCT was safe, cost-effective and resulted in prompt myeloid engraftment.

Optimal use of G-CSF administration after hematopoietic SCT

After hematopoietic SCT (HSCT), G-CSF is commonly used to enhance stem cell engraftment to minimize the morbidity and mortality associated with prolonged neutropenia. However, there is no consensus on the optimal use of G-CSF after high-dose chemotherapy followed by HSCT. This review was performed to evaluate the evidence regarding the use of G-CSF after autologous and allogeneic HSCT. Studies investigating the use of G-CSF in comparison to control (observation or placebo), early vs delayed initiation of G-CSF, and other approaches driven by patient-specific parameters to identify optimal use of G-CSF have been reviewed. Various outcomes such as neutrophil and platelet engraftment, post-transplant length of hospital stay, post-transplant complications such as infection and GVHD, and survival have been assessed. Finally, we provide the level of evidence for each of the outcomes analyzed while evaluating strategies for using G-CSF in patients undergoing autologous or allogeneic HSCT.

A Phase 3, Randomized, Placebo-controlled Trial of Filgrastim in Patients with Haematological Malignancies Undergoing Matched-related Allogeneic Bone Marrow Transplantation

Introduction

Recombinant granulocyte colony-stimulating factor (G-CSF) may aid engraftment post high-dose chemo-/radiotherapy in patients with haematological malignancies undergoing allogeneic bone marrow transplantation (BMT); however, the effects of G-CSF on graft-versus-host disease (GvHD), relapse, and survival are not well defined.

Methods

In this double-blind, randomized, placebo-controlled, multicentre, phase 3 study, the effects of the G-CSF Filgrastim on neutrophil and platelet recovery, and on clinical outcomes were evaluated. Patients (12–55 years) receiving an allogeneic BMT for a haematological malignancy were randomized to receive Filgrastim 5 µg/kg or placebo. Study treatment was continued until patients achieved an absolute neutrophil count (ANC) ≥0.5 × 10⁹/L, or until day 42.

Results

Fifty-one patients (Filgrastim, N = 25; placebo, N = 26) were evaluable. Patients treated with Filgrastim had significantly faster engraftment with ANC ≥0.5 × 10⁹/L being achieved after a median (range) of 15.0 (1.0–22.0) days vs. 19.0 (15.0–28.0) days for placebo (P< 0.0001). The incidence of GvHD was comparable for both groups. During the limited follow-up (2 years), Filgrastim had no adverse effect on mortality and possibly reduced the rate of relapse.

Allogeneic stem cell transplantation: low immunoglobulin levels associated with decreased survival

The aim of this study was to evaluate the effects and kinetics of IgG levels after allogeneic stem cell transplantation (SCT). This study retrospectively examines 179 consecutive patients undergoing SCT between 1995 and 2002. Diagnoses included acute and chronic leukemia (n=136), solid tumors (n=11), other malignancies (n=16) and non-malignant diseases (n=16). Standard myeloablative conditioning was given to 146 patients, and 33 patients received reduced intensity conditioning. Serum samples for measurement of IgG levels were collected 3, 6 and 12 months after SCT, and then yearly. IgG levels increased after SCT throughout the study period. Factors that were associated with low IgG levels after SCT were acute graft-versus-host disease (GVHD), patient age < or =30 years, female donor-to-male recipient, not receiving anti-thymocyte globulin and type of GVHD prophylaxis. Compared to patients with moderately low or normal levels as measured twice during the first year after transplantation, patients with low IgG levels (<4 g/l) showed a decreased survival rate (54 vs 71%, P=0.04) and an increased incidence of transplant-related mortality (27 vs 9%, P<0.01). IgG levels generally increase after SCT. Persistent low levels of IgG are a risk factor for death after SCT.

Risk factors for acute graft-versus-host disease grades II-IV after reduced intensity conditioning allogeneic stem cell transplantation with unrelated donors: a single centre study

We analysed factors associated with moderate to severe acute GVHD in 111 patients treated with fludarabin-based reduced intensity conditioning (RIC) and allogeneic haematopoietic stem cell transplantation (HSCT). Most patients had a haematological malignancy. Donors were 97 HLA-A, -B and -DRbeta1 identical unrelated and 14 HLA-A, -B or -DRbeta1 allele mismatched unrelated donors. In the univariate analysis, we found ten factors associated with acute GVHD. These were diagnosis (P=0.06), GVHD prophylaxis with combinations other than CsA+MTX (P=0.006), graft nucleated (P<0.001) and CD34 (P<0.001) cell-dose, bidirectional ABO mismatch (P=0.001), conditioning (P=0.002), hospital vs home-care (P=0.06), ATG dose (P<0.001), donor herpes virus serology (P=0.07) and an immunized female donor to male recipient (P=0.05). In the multivariate analysis, three factors remained significant: a high CD34 cell dose (P<0.001), low dose (4 mg/kg) ATG (P<0.001), and an immunized female donor to male recipient (P<0.01). Patients receiving a CD34 cell dose > or =17.0 x 10(6) per kg had a higher incidence of GVHD, 53.7%, compared to 22.3% in patients receiving a lower dose (P=0.002). In patients without any of these risk factors (n=70), the incidence of acute GVHD was 14.1%, while it was 38.0 and 85.0% in patients with one (n=29) or two (n=10) risk factors (P<0.001). We concluded that risk factors for acute GVHD using RIC are similar as using myeloablative conditioning.

Granulocyte and erythropoietic stimulating proteins after high-dose chemotherapy for myeloma

High-dose chemotherapy is an established treatment for patients with myeloma. In randomized trials it has been shown to prolong disease-free survival by around 1 year compared to patients receiving chemotherapy alone. Physically and psychologically high-dose therapy takes its toll on the patient who may be in hospital for around 3 weeks and take some weeks or months to convalesce after discharge. Granulocyte colony stimulating factors and erythropoietic stimulating agents will speed neutrophil and red cell recovery, respectively, when used at an appropriate time after the high-dose chemotherapy. The clinical value of these laboratory findings is uncertain and the role of these agents after high-dose chemotherapy remains a subject for debate.

Granulocyte colony-stimulating factor for the induction of T-cell tolerance

In recent years, investigators have unraveled a previously unrecognized role for granulocyte colony-stimulating factor (G-CSF) in the regulation of T-cell and dendritic cell functions. The experimental evidence in favor of G-CSF-mediated immune regulation includes the ability to skew T-cell cytokine secretion to T-helper type 2 responses, and to promote regulatory T-cell and tolerogenic dendritic cell differentiation. Accordingly, beneficial effects of G-CSF have been detected in animal models of immune-mediated diseases, including posttransplantation graft-versus-host disease, experimental autoimmune encephalomyelitis, lupus nephritis, inflammatory bowel disease, and diabetes. The growing body of evidence supporting a novel role for G-CSF in the induction of T-cell tolerance is reviewed herein.

Hematopoietic Growth Factors Including Keratinocyte Growth Factor in Allogeneic and Autologous Stem Cell Transplantation

The aim of hematopoietic stem cell transplantation (HSCT) is to cure patients of malignancies, autoimmune diseases, and immunodeficiency disorders by redirecting the immune system: the often described graft-versus-leukemia (GVL) or graft-versus-tumor (GVT) effects. Unfortunately, fulfillment of this goal is often hampered by relapse of the underlying disease, graft-versus-host disease (GVHD), or severe opportunistic infections, which account for the majority of post-transplantation deaths. Moreover, studies of long-term survivors of transplantation indicate an accelerated immune aging due to the transplantation procedure itself, preceding chemo- or radiotherapy, and acute and chronic GVHD. Significant advances have been made towards overcoming these obstacles by enhancing immune reconstitution with hematopoietic growth factors (HGFs) such as granulocyte colony-stimulating factor (G-CSF) or erythropoietin (EPO) or through the application of cytokines. In addition, there are approaches to promote the thymic-dependent development of naive T cells, which are prepared for the interaction with a multitude of pathogens. Examples are the application of keratinocyte growth factor (KGF), neuroendocrine hormones such as growth hormone or prolactin, sex hormone ablation, or the invention of a three-dimensional artificial thymus based on a cytomatrix. Might these measures result in a higher rate of healthy and fully recovered patients? Here we review progress in each of these areas.

Major ABO blood group mismatch increases the risk for graft failure after unrelated donor hematopoietic stem cell transplantation

Two hundred twenty-four patients with leukemia transplanted with an unrelated donor between 1991 and 2003 at the Karolinska University Hospital were analyzed according to association between graft failure and ABO, RhD, MNSs, and Kidd blood group antigen compatibility. Median age was 29 years (range: 0-55). Conditioning consisted of total-body irradiation or busulfan-based myeloablative conditioning. A bone marrow graft was given to 152 patients, and 72 patients received peripheral blood stem cells. Most patients received graft-versus-host disease prophylaxis with cyclosporine and MTX. Graft failure (GF) was seen in 6 (2.7%) patients. In the multivariate analysis major ABO mismatch (odds ratio [OR] 14.9, 95% confidence interval [CI] 2.01-110, P = .008) and HLA-allele mismatch (6.42, 1.19-34.8, P = .03) was significantly associated to GF. In patients with and without major ABO mismatch the incidence of GF was 7.5% and 0.6% (P = .02), respectively. Using an ABO major mismatched graft increases the risk for GF after unrelated donor hematopoietic stem cell transplantation.

Unrelated versus related allogeneic stem cell transplantation after reduced intensity conditioning

BACKGROUND

The use of reduced intensity conditioning (RIC) regimens in allogeneic hematopoietic stem cell transplantation (HSCT) has increased over the past five years.

PATIENTS

In this study, involving 137 patients, we compared the outcome after RIC in patients receiving grafts from matched unrelated donors (MUD; n=74) and sibling donors (n=63). The MUD and sibling groups were comparable regarding diagnosis, including solid tumors and hematological malignancies, and conditioning regimens.

RESULTS

Engraftment was successful in most patients (88%), with no significant difference between MUD and sibling transplants. Cytomegalovirus (CMV) infection was more common in the MUD group (65%) than in the sibling group (46%) (P=0.04). No difference in severe acute graft-versus-host disease (GVHD) was found between the groups. However, the incidence of chronic GVHD was higher after sibling transplants. This was probably due to higher donor age in this group, since this was the only significant risk factor for chronic GVHD in multivariate analysis. The incidence of transplant related mortality (TRM) was significantly higher after MUD transplantation (40%) than after sibling transplantation (16%) (P<0.01). Because relapse/disease progression was more common after sibling transplantation, there was no significant difference in overall survival between the two groups.

CONCLUSION

Using unrelated donors after RIC is feasible, but it resulted in more CMV infection and increased transplant-related mortality. Survival was comparable to that of sibling transplants.

Meta-Analysis of Randomized Controlled Trials of Prophylactic Granulocyte Colony-Stimulating Factor and Granulocyte-Macrophage Colony-Stimulating Factor After Autologous and Allogeneic Stem Cell Transplantation

Purpose

The primary objective of our meta-analysis was to determine whether prophylactic hematopoietic colony-stimulating factors (CSFs) after hematopoietic autologous and allogeneic stem-cell transplantation (SCT) reduced documented infections. Our secondary objectives were to determine whether prophylactic CSFs affected other outcomes including parenteral antibiotic therapy duration, infection-related mortality, graft-versus-host disease (GVHD), or treatment-related mortality.

Methods

We included studies if there was random assignment between CSFs and placebo/no therapy and CSFs were given after SCT and before recovery of neutrophils. From 3,778 reviewed study articles, 34 were included based on predefined inclusion criteria. All analyses were conducted using a random effects model.

Results

CSFs reduced the risk of documented infections (relative risk [RR] 0.87; 95% CI, 0.76 to 1.00; P = .05) and duration of parenteral antibiotics (weighted mean difference, −1.39 days, 95% CI, −2.56 to −0.22; P = .02) but did not reduce infection-related mortality (RR, 0.76; 95% CI, 0.41 to 1.44; P = .4). CSFs did not increase grade 2 to 4 acute GVHD (RR, 1.03; 95% CI, 0.81 to 1.31; P = .8) or treatment-related mortality (RR, 1.00; 95% CI, 0.78 to 1.29; P = .98).

Conclusion

CSFs were associated with a small reduction in the risk of documented infections but did not affect infection or treatment-related mortality.

Costs of allogeneic hematopoietic stem cell transplantation

BACKGROUND

This study aims to determine the total costs after allogeneic hematopoietic stem cell transplantation (ASCT) and factors associated with increases or decreases in costs.

METHODS

We collected all in- and outpatient costs during 5 years in 93 patients who had undergone ASCT in 1998 and 1999 at our unit. The inpatient costs included all those related to a patient from the first day of admission until discharge and then all costs of readmission in the Stockholm area.

RESULTS

The total median cost of five posttransplant years was 139,414 (52,095-345,640) euros (euros) or 167,296 US dollars (the rate of 1 euro is approximately 1.2 US dollars). The costs were highest during the first year-median inpatient and outpatient costs 100,650 euros and 13,066 euros, respectively. The total costs during the first year were higher in patients with acute graft-versus-host disease grades III-IV (relative hazards [RH] 1.35, P = 0.003), bacteremia (RH 1.33, P = 0.005), veno-occlusive disease of the liver (RH 1.32, P = 0.005), prophylaxis with granulocyte colony-stimulating factor (G-CSF; RH 1.31, P = 0.01), acute leukemia (RH 1.32, P = 0.008), and treatment in hospital instead of at home (RH 1.20, P < 0.07). During the early transplant period, a second transplantation (RH 1.28, P = 0.014) and hemorrhagic cystitis (HC; RH 1.24, P = 0.03) were also associated with higher costs. The total 5-year cost declined with longer survival rates (r = 0.4028, P < 0.001) and reduced intensity conditioning (RH 0.79, P=0.024).

CONCLUSION

Higher costs of ASCT were associated with retransplantation, acute leukemia, G-CSF prophylaxis, hospital care, myeloablative conditioning, and major transplant-related complications.

Allogeneic hematopoietic stem cell transplantation: state of the art and new perspectives

Allogeneic hematopoietic stem cell transplantation (ASCT) is a well-established therapy for leukemias and other immunohematopoietic disorders. In more recent years, bone marrow as stem cell source has been replaced by peripheral blood stem cells, which results in faster engraftment. Cord blood grafts are increasingly used. Conditioning prior to transplant may be myeloablative or nonmyeloablative. The latter is used preferentially in patients with high age or organ impairment. Isolation in the hospital during posttransplant pancytopenia has been challenged by promising results using home care. PCR diagnosis and new antifungal and antiviral treatment have reduced morbidity and mortality. The major threat to a successful outcome after ASCT is leukemic relapse. PCR techniques to detect recipient cells in the leukemic cell lineage or minimal residual disease enable early detection of leukemic cells. Donor lymphocyte infusions have an antileukemic effect. ASCT has shown an antitumor effect in metastatic cancers from breast, kidney, colon, ovaries, prostate and pancreas. Mesenchymal stem cells may be derived from bone marrow and have the capacity to differentiate into several mesenchymal tissues, such as bone, cartilage and fat. They seem to escape the immune system and have immunomodulatory effects in vitro and in vivo. To conclude, ASCT is a potent immunotherapy.