Peripheral blood stem cell versus bone marrow transplantation from HLA-identical sibling donors in patients with leukemia: a propensity score-based comparison from the Japan Society for Hematopoietic Stem Cell Transplantation registry

HLA-matched related peripheral blood stem cell and bone marrow transplantation with RIC regimens yield comparable outcomes for adult AML

Introduction

Understanding differences in clinical outcomes between PBSCT and BMT is important, and this study compared outcomes of HLA-matched related PBSCT and BMT using reduced-intensity conditioning (RIC) in adult acute myeloid leukemia (AML) patients.

Methods

Data from 402 patients who underwent either PBSCT (n = 294) or BMT (n = 108) between 2000 and 2022 were analyzed using the Japanese nationwide registry database. The primary endpoint was overall survival (OS), and secondary endpoints included disease-free survival (DFS), non-relapse mortality (NRM), and GVHD.

Results

Results indicated no significant difference in 3-year OS (44.6% for PBSCT vs. 46.9% for BMT, HR 1.173, P = 0.299) and DFS (42.1% vs. 41.8%, HR 1.073, P = 0.639). PBSCT was more beneficial for avoiding relapse (20.3% vs. 12.4%, HR, 0.715, P = 0.059). However, PBSCT was associated with higher NRM (20.3% vs. 12.4%, HR 1.801, P = 0.025) due to more frequent, chronic GVHD (HR 1.889, P = 0.035). Subgroup analysis did not reveal specific patient groups that benefited more from PBSCT or BMT. Incidence of extensive chronic GVHD and NRM has improved in PBSCT recipients in recent years (2014-2022).

Conclusions

We conclude that related PBSCT with RIC regimens offers comparable prognosis to BMT for adult AML patients. Further optimization of prophylactic strategies for chronic GVHD is required to improve outcomes after PBSCT.

Superiority of BM over PBSC for recipients with pre-transplant lung dysfunction in HLA-matched allogeneic HCT

BACKGROUND AIMS

Pre-transplant lung dysfunction is known to be a risk factor for non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). It is unclear which cell source gives better outcomes for patients with pulmonary dysfunction.

METHODS

We analyzed 3289 adult patients with standard-risk disease who had received HLA-matched allo-HCT, and compared outcomes between those who received peripheral blood stem cell (PBSC) vs. bone marrow (BM) in two cohorts based on the presence of a lung score by the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI): the Lung-scored (LS) and non-LS cohorts.

RESULTS

In the LS cohort, the 2-year overall survival (OS) in the BM group tended to be higher than that in the PBSC group (72.4% vs. 61.4%; P = 0.044). In the non-LS cohort, there was no significant difference between the two groups (71.7% vs. 73.2%; P = 0.13). Multivariate analyses confirmed that PBSC was significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.66; 95% CI, 1.09-2.54; P = 0.019). On the other hand, the cell source did not affect OS in the non-LS cohort (HR, 0.92; 95% CI, 0.76-1.12; P = 0.41). We found that PBSC was associated with an increased risk of NRM in the LS cohort (HR, 2.17; 95% CI, 1.16-4.05; P = 0.016), while the cell source did not significantly affect NRM in the non-LS cohort. PBSC was not identified as a risk factor for relapse in either cohort.

CONCLUSIONS

Our results suggest that BM might be beneficial for recipients with lung dysfunction in HLA-matched allo-HCT.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical sibling donors for hematological malignancies in 6064 adults from 2003 to 2020: different impacts on survival according to time period

BACKGROUND

Mobilized peripheral blood stem cells (PBSC) have been widely used instead of bone marrow (BM) as the graft source for allogeneic hematopoietic cell transplantation (HCT). Although early studies demonstrated no significant differences in survival between PBSC transplantation (PBSCT) and BM transplantation (BMT) from human leukocyte antigen (HLA)-identical sibling donors to adults with hematological malignancies, recent results have been unclear.

OBJECTIVE

The objective of this retrospective study was to compare overall survival (OS), relapse, non-relapse mortality (NRM), hematopoietic recovery and graft-versus-host disease (GVHD) between PBSCT and BMT according to the time period of HCT (2003-2008, 2009-2014, or 2015-2020).

STUDY DESIGN

We retrospectively compared the outcomes after PBSCT versus BMT in 6064 adults with hematological malignancies using a Japanese registry database between 2003 and 2020.

RESULTS

The adjusted probability of OS was significantly higher in BMT recipients compared to PBSCT recipients during the early period of 2003-2008 (adjusted hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.70-0.91; P < 0.001) and the middle period of 2009-2014 (adjusted HR, 0.80; 95% CI, 0.70-0.91; P < 0.001). However, during the late period of 2015-2020, the adjusted probability of OS was comparable between BMT and PBSCT recipients (adjusted HR, 0.94; 95% CI, 0.79-1.13; P = 0.564), which were mainly due to the reduction of NRM. There was no significant difference in the relapse rate between the groups, irrespective of the time period. Compared to BMT, PBSCT led to faster neutrophil and platelet recovery and the cumulative incidences of grades II-IV and grades III-IV acute and overall and extensive chronic GVHD were significantly higher in PBSCT recipients, irrespective of the time period.

CONCLUSIONS

PBSCT and BMT had similar survival outcomes and relapse rates in adult patients with hematological malignancies during the late time period of 2015-2020 despite the hematopoietic recovery and acute and chronic GVHD being higher in PBSCT recipients in all time periods.

Posttransplant cyclophosphamide in unrelated and related peripheral blood stem cell transplantation from HLA-matched and 1 allele mismatched donor

Posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has been increasingly used in HLA-haploidentical transplantation and recent studies also demonstrated the efficacy of PTCy in HLA-matched transplantation. We conducted a prospective multicenter phase II study to evaluate the safety and efficacy of PTCy with tacrolimus and mycophenolate mofetil in 43 patients who underwent HLA-matched (n = 21), 1 allele mismatched (n = 20), or 2 allele mismatched (n = 2) peripheral blood stem cell transplantation (PBSCT) following myeloablative (n = 28) or reduced-intensity (n = 15) conditioning. The incidence of grade III-IV acute GVHD at 100 days was 2.3%. The incidences of grades II-IV acute GVHD, all grade chronic GVHD, and moderate to severe chronic GVHD at 2 years were 16.3%, 14.0%, and 4.7%, respectively. Overall survival, disease-free survival, and non-relapse mortality at 2 years were 75.3%, 74.0%, and 7.0%, respectively. GVHD-free, relapse-free survival at 2 years was 67.0%. The rate of off-immunosuppressants in patients who survived without relapse at 2 years was 85.4%. These results indicate that PTCy is a valid option for GVHD prophylaxis in both HLA-matched and HLA 1-2 allele mismatched PBSCT.

Improved Long-Term Net Survival after Allogeneic Hematopoietic Cell Transplantation in Patients with Hematologic Malignancies over Two Decades

Allogeneic (allo-) hematopoietic cell transplantation (HCT) has evolved as a curative therapy for hematologic malignancies and diseases, with practice changes over the past 2 decades. This study aimed to evaluate the change in 5-year net survival (NS) of allo-HCT recipients in a population-based cohort over the past 2 decades, which allows the estimation of a more HCT-specific long-term survival rate by considering background mortality changes. This study included 42,064 patients with hematologic malignancies who underwent their first allo-HCT in Japan between 2000 and 2018 and were reported to the Transplant Registry Unified Management Program. We compared the 5-year NS after allo-HCT in 4 consecutive HCT periods (2000 to 2004, 2005 to 2008, 2009 to 2012, and 2013 to 2018). The 5-year NS of the latest period was estimated using the period analysis method. Adjusted excess hazard ratios (EHRs) for 5-year NS over the HCT period were analyzed using an EHR model. In addition to the analysis of all hematologic malignancies, adjusted 5-year NS for each major hematologic malignancy, including acute myelogenous leukemia, acute lymphoblastic leukemia (ALL), myelodysplastic syndrome, adult T cell leukemia/lymphoma, chronic myeloid leukemia (CML), and malignant lymphoma, was analyzed. The probability of adjusted 5-year NS after HCT improved significantly over time: 35% in 2000 to 2004, 39% in 2005 to 2008, 45% in 2009 to 2012, and 49% in 2013 to 2018. The adjusted EHRs were .90 (95% confidence interval [CI], .86 to .93) in the 2005 to 2008 period, .77 (95% CI, .74 to .80) in the 2009 to 2012 period, and .65 (95% CI, .63 to .68) in the 2013 to 2018 period, with the 2000 to 2004 period as the reference. The 5-year NS improved among all hematologic malignancies, with a significant improvement in CML and ALL. The changes in 5-year NS from the 2000 to 2004 period to the 2013 to 2018 period ranged from 46% to 66% in CML and from 41% to 59% in ALL. In addition to the large improvement of 1-year NS, smaller but continued improvement in NS between 1 and 5 years after transplantation was observed. NS at 5 years conditional on being alive at 1 year increased from 64% in 2000 to 2004 to 73% in 2013 to 2018. Even after subtracting the background mortality in the general population, we found a significant improvement in long-term allo-HCT-specific survival rates for patients with hematologic malignancies over the past 2 decades in Japan.

Impact of HLA-mismatched unrelated transplantation in patients with adult T-cell leukemia/lymphoma

This Japanese nationwide retrospective study investigated the impact of HLA-mismatched unrelated transplantation for adult T-cell leukemia-lymphoma (ATL) patients who received transplantation between 2000 and 2018. We compared 6/6 antigen-matched related donor (MRD), 8/8 allele-matched unrelated donor (8/8MUD), and 1 allele-mismatched unrelated donor (7/8MMUD) in the graft-versus-host direction. We included 1191 patients; 449 (37.7%) were in the MRD group, 466 (39.1%) in the 8/8MUD group, and 276 (23.7%) in the 7/8MMUD group. In the 7/8MMUD group, 97.5% of patients received bone marrow transplantation, and no patients received post-transplant cyclophosphamide. The cumulative incidences of non-relapse mortality (NRM) and relapse at 4 years, and the probabilities of overall survival at 4 years in the MRD group were 24.7%, 44.4%, 37.5%, in the 8/8MUD group were 27.2%, 38.2%, and 37.9%, and in the 7/8MMUD group were 34.0%, 34.4%, and 35.3%, respectively. The 7/8MMUD group had a higher risk of NRM (hazard ratio (HR) 1.50 [95% CI, 1.13-1.98; P = 0.005]) and a lower risk of relapse (HR 0.68 [95% CI, 0.53-0.87; P = 0.003]) than the MRD group. The donor type was not a significant risk factor for overall mortality. These data suggest that 7/8MMUD is an acceptable alternative donor when an HLA-matched donor is unavailable.

Efficacy and safety of allogeneic hematopoietic cell transplantation in acute myeloid leukemia patients aged > 65 years with unfavorable cytogenetics

Unrelated donor bone marrow transplantation (UR-BMT), unrelated donor cord blood stem cell transplantation (UR-CBT), and haploidentical peripheral blood stem cell transplantation (Haplo-PBSCT) are the main alternative stem cell sources for allogeneic hematopoietic cell transplantation (HCT) in Japan. The present study aimed to identify factors associated with the outcomes of UR-BMT, UR-CBT, and Haplo-PBSCT in older patients with acute myeloid leukemia (AML) and intermediate- or poor-risk cytogenetics to improve the clinical efficacy and safety of allogeneic HCT. We retrospectively analyzed data for 448 AML patients aged > 65 years who received UR-BMT (n = 102), UR-CBT (n = 250), or Haplo-PBSCT (n = 96) between 2014 and 2020. Overall survival (OS) in the UR-BMT group was superior (P = 0.033) to that in the other groups. However, all patients without complete remission (non-CR) who had Karnofsky performance status (KPS) < 80 at HCT and poor-risk cytogenetics died within 1 year after HCT. Multivariate Cox regression analysis identified KPS <80 at HCT and poor-risk cytogenetics as independent predictors of worse OS in non-CR patients. KPS < 80 may be an alternative indicator for non-CR AML patients with poor-risk cytogenetics during the selection of HCT, alternative treatments, or best supportive therapy, and the optimal KPS is important for the success of HCT.

Clinical Benefit of Low-Dose Antithymocyte Globulin-Thymoglobulin as Graft-versus-Host Disease Prophylaxis in Patients Receiving Allogeneic Peripheral Blood Stem Cell Transplantation from HLA-Identical Donors

Graft-versus-host disease (GVHD) is a major complication of allogeneic peripheral blood stem cell transplantation (PBSCT). Previous randomized studies have already shown that the use of several types of antihuman T lymphocyte immune globulin (ATG) as GVHD prophylaxis can reduce the incidence of acute GVHD and chronic GVHD. However, the efficacy and safety of PBSCT from HLA-identical donors with low-dose ATG remain unclear. This study aimed to clarify the efficacy and safety of PBSCT from HLA-identical donors with low-dose ATG compared with PBSCT from HLA-identical donors without ATG. To do so, we retrospectively analyzed the outcomes of patients who underwent allogeneic PBSCT from HLA-identical donors with low-dose ATG-thymoglobulin (ATG-T; 2.5 mg/kg) versus those who did not receive ATG-T. Patient data were collected retrospectively from the medical records of Anjo Kosei Hospital. This study was conducted from 2009 to the final follow-up in October 2022. Forty-seven of 91 patients received ATG-T between January 2009 and March 2020. ATG-T reduced the incidence rates of moderate-to-severe chronic GVHD (hazard ratio [HR], .15; 95% confidence interval [CI], .057 to .41; P < .0010) and nonrelapse mortality (HR, .21; 95% CI, .0058 to.75, P = .016) without increasing the risk of relapse. Overall survival did not differ significantly between the 2 groups; however, the low-dose ATG-T group had better moderate-to-severe chronic GVHD-free, relapse-free survival rates (HR, .47; 95% CI, .27 to .80, P = .0054) than the non-ATG-T group. In addition, multistate analysis revealed that the low-dose ATG-T group had better current GVHD-free, relapse-free survival at 24 months after transplantation (45% [95% CI, 29% to 63%)] versus 21% [95% CI, 9.1% to 34%]; P = .015). Low-dose ATG-T was not associated with increased incidence of infections or adverse events. Our findings suggest that low-dose ATG-T can be beneficial for patients receiving PBSCT from HLA-identical donors. © 2023 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Advantages of peripheral blood stem cells from unrelated donors versus bone marrow transplants in outcomes of adult acute myeloid leukemia patients

BACKGROUND AIMS

In allogeneic stem cell transplantation, unrelated donors are chosen in cases where appropriate related donors are not available. Peripheral blood stem cells (PBSCs) are more often selected as a graft source than bone marrow (BM). However, the prognostic benefits of PBSCs versus BM transplants from unrelated donors have not been carefully examined in patients with acute myeloid leukemia (AML). This study compared outcomes of adult AML patients who underwent unrelated PBSC and BM transplantation, evaluating post-transplant complications, including engraftment, graft-versus-host disease (GVHD) and infections, and determined subgroups of patients who are most likely to benefit from unrelated PBSCs compared with BM transplants.

METHODS

The authors analyzed 2962 adult AML patients who underwent unrelated PBSC or BM transplants between 2011 and 2018 (221 PBSC and 2741 BM) using the Japanese nationwide registry database, in which graft source selection is not skewed toward PBSCs.

RESULTS

In 49.7% of patients, disease status at transplantation was first complete remission (CR1). In 57.1% of cases, HLA-matched donors were selected. Myeloablative conditioning was performed in 75.1% of cases, and anti-thymocyte globulin (ATG) was added to conditioning in 10.5%. Multivariate analyses showed a trend toward favorable non-relapse mortality (NRM) in PBSC recipients compared with BM recipients (hazard ratio [HR], 0.731, P = 0.096), whereas overall survival (OS) (HR, 0.959, P = 0.230) and disease-free survival (DFS) (HR, 0.868, P = 0.221) were comparable between PBSC and BM recipients. Although the rate of chronic GVHD (cGVHD) was significantly higher in PBSC patients (HR, 1.367, P = 0.016), NRM was not increased, mainly as a result of significantly reduced risk of bacterial infections (HR, 0.618, P = 0.010), reflecting more prompt engraftments in PBSC recipients. Subgroup analyses revealed that PBSC transplantation was advantageous in patients transplanted at CR1 and in those without ATG use. PBSC recipients experienced significantly better OS and/or DFS compared with BM recipients in this patient group.

CONCLUSIONS

The authors' results confirmed the overall safety of unrelated PBSC transplantation for adult AML patients and suggested an advantage of PBSCs, especially for those in CR1. Further optimization of the prophylactic strategy for cGVHD is required to improve the overall outcome in transplantation from unrelated PBSC donors.

Anti-thymocyte globulin could potentially overcome an adverse effect of acute GVHD in matched-related PBSCT

BACKGROUND

Previous Japanese studies have shown that bone marrow transplantation (BMT) is associated with a better survival compared with peripheral blood stem cell transplantation (PBSCT) from matched related donors (MRDs). PBSCT recipients showed a higher incidence of severe graft-versus-host disease (GVHD) and non-relapse mortality (NRM) than BMT recipients. In recent years, the efficacy and safety of anti-thymocyte globulin (ATG) for PBSCT recipients has been reported from around the world.

OBJECTIVE

We aimed to compare BMT and PBSCT to identify current improvements and unmet needs among PBSCT recipients from MRDs. Moreover, we evaluated the impact of ATG administration on the outcomes for PBSCT recipients.

STUDY DESIGN

We retrospectively analyzed patients aged 16 years or older with acute leukemia, myelodysplastic syndrome, or chronic myeloid leukemia who received their first BMT or PBSCT from MRDs between 2009 and 2018 in Japan.

RESULTS

In total, 3599 transplantations were performed (BMT, 1218; PBSCT without ATG [PBSCT-ATG(-)], 2288; and PBSCT with ATG [PBSCT-ATG(+)], 93). The PBSCT-ATG(-) group had a higher NRM rate (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.08-1.57; p = 0.005) and lower overall survival (OS) rate (HR, 1.16; 95% CI, 1.04-1.30; p = 0.011) than the BMT group. Furthermore, the PBSCT-ATG(-) group had a higher incidence of grade III-IV, stage 2-4 gut, high-risk, and steroid-refractory acute GVHD than the BMT group. Acute GVHDs had a negative impact on NRM and OS rates. PBSCT-ATG(-) was also associated with a higher risk of chronic GVHD (HR: 1.89; 95% CI: 1.24-1.57; p < 0.001) and extensive chronic GVHD (HR: 1.44; 95% CI: 1.23-1.68; p < 0.001). The incidence of acute GVHD, chronic GVHD, and NRM and chronic GVHD-free relapse-free survival rates were comparable between the PBSCT-ATG(+) and BMT groups. The OS rate of patients with acute GVHD in the three donor groups was similar. Patients treated with reduced-intensity conditioning in the PBSCT-ATG(+) group had a higher relapse rate and lower OS rate than those in the BMT group.

CONCLUSIONS

In this Japanese cohort, standard calcineurin inhibitor-based GVHD prophylaxis was not sufficient for PBSCT recipients from MRDs because of the high incidence of severe acute GVHD. Moreover, prophylactic ATG was found to be a promising strategy against GVHD.

Syngeneic hematopoietic stem cell transplantation for acute myeloid leukemia: a propensity score-matched analysis

The present study evaluated outcomes and prognostic factors in adult patients with acute myeloid leukemia (AML) after syngeneic hematopoietic stem cell transplantation (HSCT). Among patients in first complete remission (CR1), outcomes of syngeneic HSCT (Syn) were compared with those of autologous HSCT (Auto), allogeneic HSCT from human leukocyte antigen (HLA)-matched sibling donor (MSD), or allogeneic HSCT from HLA-matched unrelated donor (MUD). Among 11,866 patients receiving first HSCT, 26 in the Syn group were analyzed. The 5-year overall survival (OS) rate, the cumulative incidence of relapse, and the cumulative incidence of non-relapse mortality (NRM) were 47.8%, 59.6%, and 4.6%, respectively. The OS was significantly better in patients in CR1 (n = 13) than in patients in non-CR1 (P = 0.012). Furthermore, 39 patients in CR1 each were assigned to the Auto, MSD, and MUD groups using propensity score matching. The 5-year OS in the Syn (68.4%) was not significantly different from those in the Auto (55.9%, P = 0.265), MSD (62.4%, P = 0.419), or MUD (63.7%, P = 0.409) groups. A higher relapse in the Syn than in the MSD and MUD groups was offset by lower NRM. In summary, syngeneic HSCT might be an alternative option for AML patients in CR1.

Oral microorganisms and bloodstream infection in allogeneic hematopoietic stem cell transplantation

OBJECTIVES

We aimed to compare oral and pathogenic microorganisms in bloodstream infections (BSIs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We also investigated the relationship between BSIs and oral mucositis to identify the ratio of BSIs caused by oral microorganisms and the pathogenic microorganisms involved.

MATERIALS AND METHODS

We collected data on BSIs in 96 patients who underwent allo-HSCT in our institute between April 2009 and December 2019, including BSI pathogens isolated from blood cultures (BBSIs) and microorganisms isolated from washing the oral cavity with sterile distilled water. Oral microorganisms obtained at the onset of BSI (OBSIs) and during allo-HSCT (OSCTs) were defined as isolates collected during the week of blood culturing. Study entry was limited to samples collected up to 1 month after allo-HSCT without BSI. When the BBSI and OBSI were the same, we considered the oral microorganism to have caused the BSI.

RESULTS

The incidence rate of BSIs was 27%, and the predominant microorganism was coagulase-negative Staphylococci. Normal bacterial flora were decreased to 15.8% in OBSIs and 25.5% in OSCTs. The distribution of microorganisms without normal bacterial flora showed significant difference between BBSIs and OSCTs (p < 0.05). Oral mucositis was found in 72.9%, and BSI caused by oral microorganisms occurred in 46.2% of BSIs in allo-HSCT patients.

CONCLUSION

The distribution of microorganisms obtained from blood in patients with BSI during allo-HSCT was found to be similar to that of microorganisms from oral cultures.

CLINICAL RELEVANCE

Oral microorganism monitoring may be able to predict BSI during allo-HSCT.

Effect of allogeneic HCT from unrelated donors in AML patients with intermediate- or poor-risk cytogenetics: a retrospective study from the Japanese Society for HCT

This study aimed to analyze the factors associated with outcomes of bone marrow transplantation (UR-BMT) or cord blood stem cell transplantation from unrelated donors (UR-CBT). We assessed the time from diagnosis to transplantation among acute myeloid leukemia (AML) patients with intermediate- or poor-risk cytogenetics to identify the potential clinical efficacy of transplantation. We retrospectively analyzed 5331 patients who received UR-BMT or UR-CBT between 2008 and 2017. Patients were divided into four groups according to time from diagnosis to transplantation: (1) UR-BMT and > 5 months (n = 2353), (2) UR-BMT and ≤ 5 months (n = 379), (3) UR-CBT and > 5 months (n = 1494), and (4) UR-CBT and ≤ 5 months (n = 1106). There was no difference in overall survival (OS) for transplantation at ≤5 months and > 5 months in patients with first complete remission for both UR-BMT and UR-CBT, but OS in patients with primary induction failure (PIF) and transplantation at ≤ 5 months was significantly higher in the UR-CBT group compared with that at >5 months (P < 0.001). Multivariate Cox regression analysis also showed that transplantation at >5 months in patients with PIF was an independent predictor of poorer OS. Therefore, UR-CBT at ≤ 5 months after diagnosis is an alternative option for AML patients with PIF.

Low-dose anti-thymocyte globulin for GVHD prophylaxis in HLA-matched allogeneic peripheral blood stem cell transplantation

Allogeneic peripheral blood stem cell transplantation (PBSCT) is associated with an increased risk of severe acute and chronic graft-versus-host disease (GVHD) compared to bone marrow transplantation. Anti-thymocyte globulin (ATG) can reduce severe acute and chronic GVHD in PBSCT; however, an optimal dose of ATG remains undefined. We conducted a multicenter phase II study to investigate safety and efficacy of low-dose ATG (a total of 2 mg/kg Thymoglobulin) in patients undergoing HLA-matched PBSCT after myeloablative conditioning. The primary endpoint was grades III-IV GVHD at 100 days. Seventy-seven patients were enrolled and 72 patients with a median age of 46.5 years were eligible for analysis. The primary endpoint, cumulative incidence of grades III-IV acute GVHD at 100 days was 1.4% (95% CI, 0.1-6.7%), which was greatly less than our pre-defined statistical threshold value (18.0%). The incidence of chronic GVHD at 1 year was also low (all-grade; 15.3%, moderate to severe; 5.6%). Non-relapse mortality, relapse, overall survival, disease-free survival, and GVHD-free, relapse-free survival at 1 year were 4.2%, 20.8%, 84.7%, 75.0%, and 69.4%, respectively. Low dose thymoglobulin is promising to reduce severe acute and chronic GVHD in HLA-matched PBSCT following myeloablative conditioning.

Circulating Th17.1 cells as candidate for the prediction of therapeutic response to abatacept in patients with rheumatoid arthritis: An exploratory research

T-helper (Th)17.1 cells exhibit high pathogenicity in inflammatory diseases. This study aimed to identify the changes in the proportions of Th subsets, including Th17.1, which are associated with abatacept treatment response in Japanese patients with rheumatoid arthritis. On the basis of the results, we assessed whether Th17.1 is a potential cellular biomarker. Multicolor flow cytometry was used to determine the circulating Th subsets among CD4+ T lymphocytes in 40 patients with rheumatoid arthritis before abatacept treatment. All the patients received abatacept treatment for 24 weeks; changes in disease activity score, including 28-joint count C-reactive protein, and responsiveness indicated by other indices to abatacept treatment were evaluated according the European League Against Rheumatism criteria (good and moderate responders and nonresponders). The correlation between the abatacept responses and the proportions of Th subsets (baseline) was analyzed. Logistic regression analysis with inverse probability weighting method was performed to calculate the odds ratio adjusted for patient characteristics. The proportion of baseline Th17.1 cells was significantly lower in patients categorized as good responders than in those categorized as non-good responders (moderate responders and nonresponders; p = 0.0064). The decrease in 28-joint count C-reactive protein after 24 weeks of abatacept therapy showed a significant negative correlation with the proportion of Th17.1 cells. The adjusted odds ratio for achieving good response in patients with baseline Th17.1 levels below the median value was 14.6 (95% confidence interval, 2.9–72.3; p = 0.0021) relative to that in the remaining patients. The proportion of Th17.1 cells at baseline is a good candidate for predicting abatacept treatment response in Japanese patients. These novel findings may represent a significant step in the pursuit of precision medicine.

Time-Varying Effects of Graft Type on Outcomes for Patients with Acute Myeloid Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

This study aimed to investigate time-varying effects of graft type on outcomes for patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplant. For this purpose we analyzed 3952 patients, 720 of whom underwent matched related bone marrow transplantation (BMT), 1004 matched related peripheral blood stem cell transplantation (PBSCT), 856 matched unrelated BMT, and 1372 umbilical cord blood transplantation (UCBT) during complete remission. The 4-year relapse-free survival (RFS) rates were 59.1%, 52.8%, 59.5%, and 50.6%, respectively. Compared with related BMT, related PBSCT, unrelated BMT, and UCBT were associated with higher risk of nonrelapse mortality and unrelated BMT and UCBT with lower risk of relapse. As a result, both RFS and overall survival were comparable between related BMT and unrelated BMT but were worse for related PBSCT and UCBT than for related BMT. Adverse impact of UCBT was observed only during the early phase of transplant, whereas that of related PBSCT continued even after 2 years post-transplant. Our findings raise concerns about the increased risk of late nonrelapse mortality with the use of PBSC grafts and suggest that related BMT is preferable to related PBSCT; matched unrelated BMT is the next choice in the absence of a matched related donor.

Phase I study of graft-versus-host disease prophylaxis including bortezomib for allogeneic hematopoietic cell transplantation from unrelated donors with one or two HLA loci mismatches in Japanese patients

This phase I study was designed for graft-versus-host disease (GVHD) prophylaxis including bortezomib in allogeneic hematopoietic cell transplantation (allo-HCT) from human leukocyte antigen (HLA)-mismatched unrelated donors in Japanese patients. Patients were administered bortezomib on days 1, 4, and 7, with short-term methotrexate and tacrolimus. Three bortezomib dose levels were prepared (1.0, 1.3, and 1.5 mg/m²). A dose of 1.3 mg/m² was planned for administration to the initial six patients, and was adjusted if dose-limiting toxicity developed. Five of six patients enrolled for the initial dose had bone marrow donors. Two cases had single-antigen and single-allele mismatches; four had single-antigen mismatch at the A, B, C, and/or DRB1 loci in the GVH direction. All patients achieved neutrophil engraftment and complete donor chimerism. Three patients developed grade II acute GVHD, and none developed grade III-IV GVHD or any dose-limiting toxicity attributable to bortezomib by day 100. Two patients developed late-onset acute GVHD, and two developed chronic GVHD, but all cases were manageable. All patients were alive without relapse after a median follow-up period of 52 months. The optimal dose of bortezomib was determined to be 1.3 mg/m². Prophylaxis against GVHD using a regimen including bortezomib thus seems feasible for HLA-mismatched unrelated allo-HCT.

Short-term clinical outcomes after HLA 1-locus mismatched uPBSCT are similar to that after HLA-matched uPBSCT and uBMT

In Japan, use of unrelated peripheral blood stem cell transplantation (uPBSCT) from HLA-mismatched unrelated donors has recently been approved. We compared outcomes between HLA-matched and 1-locus mismatched uPBSCT, as well as the impact of HLA disparity in uPBSCT and in unrelated bone marrow transplantation (uBMT). In total, 5862 uBMT recipients and 234 uPBSCT recipients were included. In terms of HLA allele disparity, 185 uPBSCT patients (79.1%) had no HLA mismatch, and 49 (20.9%) had 1-locus mismatch; in comparison, 3585 uBMT patients (61.2%) had no HLA mismatch, and 2277 (38.8%) had 1-locus mismatch. The impact of 1-locus mismatch as compared with match in uPBSCT was not significantly higher than in uBMT [hazard ratio (HR) = 1.02 and 1.27 for grade III-IV acute graft-versus-host disease, HR = 0.98 and 1.14 for non-relapse mortality, and HR = 0.87 and 1.06 for overall survival, respectively]. In conclusion, the impact of single-locus mismatch on short-term outcomes was comparable in uPBSCT and uBMT. Larger studies with longer follow-up are needed to assess long-term outcomes.

Bone marrow versus peripheral blood as a graft source for haploidentical donor transplantation in adults using post-transplant cyclophosphamide-A systematic review and meta-analysis

BACKGROUND

Peripheral-blood (PB) and bone marrow (BM) are both widely used in hematopoietic stem cell transplantation (HSCT). However, it is unclear whether PB or BM produces a more satisfactory outcome in haploidentical HSCT, particularly for patients using post-transplant cyclophosphamide (PTCy), which is the standard therapy. However, to date, no meta-analysis focusing on this issue has been published.

METHODS

We systematically searched PubMed, MEDLINE, Web of Science, the Cochrane Library and the ClinicalTrials.gov website for studies regarding the use of BM or PB in haploidentical HSCT for hematological malignancies in adults using PTCy. Data were analyzed using Open Meta-Analyst statistical software.

RESULTS

Fourteen studies were extracted including four comparative retrospective reports and ten single-arm reports, with a total of 1759 patients received PTCy haploidentical HSCT (462 patients received PBSCT, 1297 patients received BMT). The pooled outcomes of comparative retrospective studies showed significantly higher incidence of grade III-IV acute graft-versus-host disease (GVHD) (OR = 1.741, 95%CI 1.032-2.938), incidence of grade IIIV acute GVHD (OR = 1.778, 95%CI 1.314, 2.406) and engraftment rate (OR = 1.843, 95%CI 1.066-3.185) in the PB group. No significant differences were found on the incidence of relapse, 2-year overall survival (OS) and disease-free survival (DFS), acute IIIV GVHD and chronic GVHD between PBSCT or BMT.

CONCLUSION

The efficacy of PB is not inferior to BM for patients undergoing PTCy haploidentical HSCT with regard to primary outcomes, including OS, DFS, NRM and relapse. However, with regards to convenience and pain relief, PB graft is suitable for haploidentical HSCT, but with a higher risk of acute GVHD.

Hematopoietic stem cell transplantation for acute myeloid leukemia

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) yields a high rate of curability for acute myeloid leukemia (AML), it is also associated with transplant-related morbidity and mortality (TRM). The risk and severity of TRM increase with the use of an alternative donor graft in the absence of an HLA-matched sibling donor (MSD). With the declining birthrate and aging of the population, the numbers of patients with an MSD are decreasing, and alternative donor transplants, including the post-transplant cyclophosphamide method using haplo-identical donors, are increasing. Autologous (auto)-HSCT, which enables the intensification of chemotherapy, has the advantage of high availability of a transplant graft, and is associated with a lower TRM, but these benefits may be offset by a higher rate of relapse due to the lack of a graft-versus-leukemia (GVL) effect. Although allo-HSCT remains the first-line treatment for poor and very-poor-risk patients, auto-HSCT is again gaining increased attention. It has also recently been suggested that cord blood grafts may induce a stronger GVL effect than other grafts; as such, the positioning of cord blood transplantation should also be reconsidered for AML patients.

Prospective observational study on the first 51 cases of peripheral blood stem cell transplantation from unrelated donors in Japan

The Japan Marrow Donor Program (JMDP) has facilitated unrelated peripheral blood stem cell transplantation (URPBSCT) since 2010. We conducted a prospective multicenter observational study to evaluate the feasibility of such transplantation. Between 2011 and 2014, 51 patients underwent URPBSCT from 8/8 allele-matched donors for hematological malignancies. The median age of the patients was 50 years; 21 had high-risk disease. Myeloablative conditioning regimens were used in 31 patients, and tacrolimus based graft-versus-host disease (GVHD) prophylaxis was used for all patients. The cumulative rate of engraftment was 96%. With a median follow-up period of 610 days for survivors, 100-day and 1-year overall survival rates were 86 and 59%, respectively. The cumulative incidence of non-relapse mortality and relapse at 1 year were 14 and 35%, respectively. The incidence of grade II to IV acute GVHD at 100 days and extensive type of chronic GVHD at 1 year were 25 and 32%, respectively. The probability of overall survival was comparable with that of bone marrow transplantation from HLA matched-unrelated donors in Japan, although the incidence of chronic GVHD was higher. Further follow-up with more patients is clearly warranted to establish the optimal use of URPBSCT together with the approaches of minimizing chronic GVHD.

CD56bright natural killer regulatory cells in filgrastim primed donor blood or marrow products regulate chronic graft-versus-host disease: the Canadian Blood and Marrow Transplant Group randomized 0601 study results

Randomized trials have conclusively shown higher rates of chronic graft-versus-host disease with filgrastim-stimulated apheresis peripheral blood as a donor source than unstimulated bone marrow. The Canadian Blood and Marrow Transplant Group conducted a phase 3 study of adults who received either filgrastim-stimulated apheresis peripheral blood or filgrastim-stimulated bone marrow from human leukocyte antigen-identical sibling donors. Because all donors received the identical filgrastim dosing schedule, this study allowed for a controlled evaluation of the impact of stem cell source on development of chronic graft-versus-host disease. One hundred and twenty-one evaluable filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow patient donor products were immunologically characterized by flow cytometry and tested for their association with acute and chronic graft-versus-host disease within 2 years of transplantation. The immune populations evaluated included, regulatory T cells, central memory and effector T cells, interferon γ positive producing T cells, invariate natural killer T cells, regulatory natural killer cells, dendritic cell populations, macrophages, and activated B cells and memory B cells. When both filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow were grouped together, a higher chronic graft-versus-host disease frequency was associated with lower proportions of CD56^bright natural killer regulatory cells and interferon γ-producing T helper cells in the donor product. Lower CD56^bright natural killer regulatory cells displayed differential impacts on the development of extensive chronic graft-versus-host disease between filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow. In summary, while controlling for the potential impact of filgrastim on marrow, our studies demonstrated that CD56^bright natural killer regulatory cells had a much stronger impact on filgrastim-stimulated apheresis peripheral blood than on filgrastim-stimulated bone marrow. This supports the conclusion that a lower proportion of CD56^bright natural killer regulatory cells results in the high rate of chronic graft-versus-host disease seen in filgrastim-stimulated apheresis peripheral blood. clinicaltrials.gov Identifier: 00438958.

Comparison of Autologous and Unrelated Transplants for Cytogenetically Normal Acute Myelogenous Leukemia

Allogeneic stem cell transplantation (SCT) from an HLA-matched sibling donor (MSD) is a postremission treatment that offers a potential cure for adults with cytogenetically normal (CN) acute myelogenous leukemia (AML) in first complete remission (CR1). The best alternative in the absence of an MSD remains unclear, however. The aim of this study was to retrospectively compare the outcomes of autologous peripheral blood stem cell transplantation (auto-PBSCT; n = 177) and allogeneic bone marrow transplantation (BMT) from an HLA-matched unrelated donor (MUD; n = 173) in adult patients with CN-AML/CR1. Both the multivariate analysis (hazard ratio [HR], 1.18; 95% confidence interval [CI], 0.71 to 1.97; P = .53) and propensity score models (HR, 1.40; 95% CI, 0.80 to 2.43; P = .24) indicated that the leukemia-free survival (LFS) rate of auto-PBSCT was not significantly different from that of MUD-BMT. These results suggest that in the absence of an available MSD, auto-PBSCT remains a viable alternative as postremission therapy in patients with CN-AML/CR1.

Comparison of graft-versus-host disease-free, relapse-free survival according to a variety of graft sources: antithymocyte globulin and single cord blood provide favorable outcomes in some subgroups

Graft-versus-host disease-free relapse-free survival, which is defined as the absence of grade III-IV acute graft-versus-host disease, systemically treated chronic graft-versus-host disease, relapse, and death, is a novel, meaningful composite end point for clinical trials. To characterize risk factors and differences in graft-versus-host disease-free relapse-free survival according to a variety of graft sources, we analyzed 23,302 patients with hematologic malignancy that had a first allogeneic transplantation from 2000 through 2013 using the Japanese national transplant registry database. The 1-year graft-versus-host disease-free relapse-free survival rate was 41% in all patients. The rate was higher after bone marrow transplantation than after peripheral blood stem cell transplantation due to the lower risks of III-IV acute and chronic graft-versus-host disease. The rate was highest after HLA-matched sibling bone marrow transplantation. The rate after single cord blood transplantation was comparable to that after HLA-matched unrelated bone marrow transplantation among patients aged 20 years or under, and was comparable or better than other alternative graft sources among patients aged 21 years or over, due to the low risk of chronic graft-versus-host disease. Other factors associated with better graft-versus-host disease-free relapse-free survival include female patients, antithymocyte globulin prophylaxis (for standard-risk disease), recent years of transplantation, sex combinations other than from a female donor to a male patient, the absence of prior autologous transplantation, myeloablative conditioning, negative cytomegalovirus serostatus, and tacrolimus-based prophylaxis. These results provide important information to guide the choice of graft sources and are benchmarks for future graft-versus-host disease prophylaxis studies.

Risk Factors and Outcome of Chronic Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation-Results from a Single-Center Observational Study

Chronic graft versus host disease (cGVHD) is the most frequent long-term complication after allogeneic stem cell transplantation (allo-SCT) and results in impaired quality of life and increased long-term morbidity and mortality. We analyzed 243 patients with cGVHD, documented according to the 2005 revised National Institutes of Health consensus criteria, to identify risk factors for the occurrence of cGVHD and outcomes for the patients with cGVHD. Patients without evidence of cGVHD (n = 147) were used as controls. Performing univariate and multivariate Cox regression analyses, we identified prior acute GVHD grades III or IV (hazard ratio [HR], 2.01; P = .005), use of peripheral blood stem cell graft (HR, 2.10; P = .03), and HLA-mismatched allo-SCT from unrelated donor (HR, 1.57; P = .02) as independent risk factors for cGVHD. Performing Kaplan-Meier analyses, progressive compared with de novo and quiescent onset of cGVHD and a platelet count of less than 100/nL compared with more than 100/nL at the time of cGVHD onset were associated with a significantly increased cumulative incidence of transplantation-related mortality (TRM) and significantly decreased overall survival. Furthermore, we found a significantly higher incidence of TRM in patients with severe cGVHD compared with patients without cGVHD (58% versus 11%, P < .0001). However, in subgroup analysis, patients with severe cGVHD and involvement of the lung, liver, or gastrointestinal (GI) tract had a 6.5-fold significantly higher incidence of TRM (72%), whereas patients with severe cGVHD lacking lung, liver, or GI involvement had only a 2.8-fold significantly higher incidence of TRM (31%) compared with patients without cGVHD (11%; P < .0001 and P = .03). Patients without lung, liver, or GI involvement did not have a significantly different TRM compared with patients with moderate cGVHD (31% versus 25%, P = .52). In conclusion, we confirm prior known risk factors for the occurrence of cGVHD and subsequent mortality and we provide evidence that the presence of lung, liver, or GI involvement in patients with severe cGVHD defines a subgroup with high mortality after allo-SCT; however, in the absence of these risk factors, the outcome appears not to be impaired compared with moderate cGVHD.

Haploidentical hematopoietic stem cell transplantation without total body irradiation for pediatric acute leukemia: a single-center experience

Hematopoietic stem cell transplantation (HSCT) is a promising method for therapy of pediatric patients with acute leukemia. However, less availability of matched donors limited its wide application. Recently, haploidentical HSCT has become a great resource. Here, we have retrospectively reported our experience of 20 pediatric patients with acute leukemia who underwent haploidentical HSCT without total body irradiation (TBI) myeloablative regimen in our center from November 2007 to June 2014. All the patients attained successful HSCT engraftment in terms of myeloid and platelet recovery. Thirteen patients developed grade I–IV acute graft-versus-host disease (a-GVHD). The incidence of grade I–II a-GVHD, grade III–IV a-GVHD, and chronic GVHD (c-GVHD) was 45%, 20%, and 25%, respectively. The mean myeloid and platelet recovery time was 13.20±2.41 and 19.10±8.37 days. The median follow-up time was 43.95±29.26 months. During the follow-up, three patients died. The overall survival (OS) rate was 85%. The present study indicated that haploidentical HSCT without TBI myeloablative regimen significantly improved the OS rate of pediatric patients with acute leukemia.

Graft-versus-Host Disease after HLA-Matched Sibling Bone Marrow or Peripheral Blood Stem Cell Transplantation: Comparison of North American Caucasian and Japanese Populations

The risk of acute graft-versus-host disease (GVHD) after HLA-matched sibling bone marrow transplantation (BMT) is lower in Japanese than in Caucasian patients. However, race may have differential effect on GVHD dependent on the graft source. North American Caucasian and Japanese patients receiving their first allogeneic BMT or peripheral blood stem cell transplantation from an HLA-matched sibling for leukemia were eligible. BMT was performed in 13% of the Caucasian patients and in 53% of the Japanese patients. On multivariate analysis, the interaction term between race and graft source was not significant in any of the models, indicating that graft source does not affect the impact of race on outcomes. The risk of grade III or IV acute GVHD was significantly lower in the Japanese patients compared with the Caucasian patients (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.57 to 0.96), which resulted in lower risk of nonrelapse mortality in the Japanese patients (HR, 0.69; 95% CI, 0.54 to 0.89). The risk of relapse was also lower in this group. The lower risks of nonrelapse mortality and relapse resulted in lower overall mortality rates among the Japanese patients. In conclusion, our data indicate that irrespective of graft source, the risk of severe acute GVHD is lower in Japanese patients, resulting in a lower risk of nonrelapse mortality.

Comparable outcomes between autologous and allogeneic transplant for adult acute myeloid leukemia in first CR

Although allogeneic hematopoietic stem cell transplantation from an HLA-matched sibling donor (MSD) is a potentially curative post-remission treatment for adults with acute myeloid leukemia (AML) in their first CR, transplant-related morbidity and mortality remains a major drawback. We retrospectively compared the outcomes of patients who underwent autologous peripheral blood stem cell transplantation (auto-PBSCT; n=375) with those who underwent allogeneic bone marrow transplantation (allo-BMT; n=521) and allo-PBSCT (n=380) from MSDs for adults with AML/CR1, in which propensity score models were used to adjust selection biases among patients, primary physicians and institutions to overcome ambiguity in the patients' background information. Both the multivariate analysis and propensity score models indicated that the leukemia-free survival rate of auto-PBSCT was not significantly different from that of allo-BMT (hazard ratio (HR), 1.23; 95% confidence interval (CI), 0.92 to 1.66; P=0.16) and allo-PBSCT (HR, 1.13; 95% CI, 0.85-1.51; P=0.40). The current results suggest that auto-PBSCT remains a promising alternative treatment for patients with AML/CR1 in the absence of an available MSD.

Risk factors and prognosis of hepatic acute GvHD after allogeneic hematopoietic cell transplantation

Hepatic acute GvHD (aGvHD) is associated with high mortality owing to poor response to immunosuppressive therapy. The pathogenesis of hepatic aGvHD differs from that of other lesions, and specific risk factors related to pre-transplant liver conditions should be determined. We conducted a cohort study by using a Japanese transplant registry database (N=8378). Of these subjects, 1.5% had hepatitis C virus Ab (HCV-Ab) and 9.4% had liver dysfunction (elevated transaminase or bilirubin levels) before hematopoietic cell transplantation (HCT). After HCT, the cumulative incidence of hepatic aGvHD was 6.7%. On multivariate analyses, HCV-Ab positivity (hazard ratio (HR), 1.93; P=0.02) and pre-transplant liver dysfunction (HR, 1.85; P<0.01), as well as advanced HCT risk, unrelated donors, HLA mismatch and cyclosporine as GvHD prophylaxis, were significant risk factors for hepatic aGvHD, whereas hepatitis B virus surface Ag was not. Hepatic aGvHD was a significant risk factor for low overall survival and high transplant-related mortality in all aGvHD grades (P<0.01). This study is the first to show the relationship between pre-transplant liver conditions and hepatic aGvHD. A prospective study is awaited to validate the results of this study and establish a new strategy especially for high-risk patients.

Bone marrow or peripheral blood stem cell transplantation from unrelated donors in adult patients with acute myeloid leukaemia, an Acute Leukaemia Working Party analysis in 2262 patients

BACKGROUND

No survival benefit of using blood stem cells instead of bone marrow (BM) has been shown in matched unrelated donor (MUD) transplantation.

DESIGN AND METHODS

In a retrospective registry analysis, we compared the use of blood stem cells (n = 1502) and BM (n = 760) from unrelated donors in patients aged 18-60 years with acute myeloid leukaemia (AML) undergoing myeloablative conditioning between 1997 and 2008. The blood stem cell recipients were older (P < 0.01), had more advanced disease (P < 0.0001) and received less total body irradiation (P < 0.0001) and more antithymocyte globulin (P = 0.01).

RESULTS

Recovery of neutrophils and platelets was faster with blood stem cells (P < 0.0001). The incidence of acute graft-versus-host disease (GVHD) was similar, but there was more chronic GVHD in the blood stem cell group [hazard ratio (HR) = 1.29, P = 0.02]. There were no significant differences in nonrelapse mortality (NRM), relapse incidence and leukaemia-free survival (LFS) between the two groups amongst patients with AML in remission. In patients with advanced leukaemia, NRM was lower (HR = 0.61, P = 0.02) and LFS was prolonged (HR = 0.67, P = 0.002) when blood stem cells were used. At 3 years, LFS for all patients, regardless of remission status, was 41% for both treatment groups. The outcome was not affected after multivariable analysis adjusted for confounders.

CONCLUSION

Blood stem cells compared with BM in MUD transplantation for patients with AML in remission resulted in the same rates of LFS. In patients with advanced leukaemia, the blood stem cell group had reduced NRM and improved LFS.

Mobilized peripheral blood stem cells compared with bone marrow from HLA-identical siblings for reduced-intensity conditioning transplantation in acute myeloid leukemia in complete remission: a retrospective analysis from the Acute Leukemia Working Party of EBMT

Reduced-intensity conditioning (RIC)-alloSCT is increasingly used for acute myelogenous leukemia. Limited data are available for the comparison of peripheral blood stem cells with bone marrow for RIC-alloSCT. We used the European Group for Blood and Marrow Transplantation (EBMT) ALWP data to compare the outcome of mobilized peripheral blood stem cells (PBSC) (n = 1430) vs. bone marrow (BM) (n = 107) for acute myelogenous leukemia (AML) patients with complete remission that underwent RIC-alloSCT from compatible sibling donors. The leukemia features, the disease status, and the time from diagnosis were similar between the two groups. Engraftment was achieved in 99% and 93% in the PBSC and BM groups, respectively (P < 0.0001). The day of engraftment was significantly earlier for the PBSC vs. the BM group, 15 (1-59) and 19 (5-69), respectively (P < 0.001). Acute GVHD, severe GVHD (grade III-IV) and chronic GVHD did not differ between the groups. leukemia-free survival (LFS), relapse, and non-relapsed mortality (NRM) were 51 ± 2%, 32 ± 1%, and 17 ± 1% vs. 50 ± 6%, 38 ± 6%, and 12 ± 3% for the PBSC and BM groups, respectively. Our results indicate faster engraftment, but no difference in GVHD, LFS, relapse, and NRM when comparing PBSC to BM grafts from sibling donors following RIC conditioning. This is the first study comparing PBSC to BM grafts in the RIC setting, analyzing a homogeneous population of patients with AML in remission. Whether PBSC should be preferred for advanced phases of the disease, where the outcome is dominated by relapse incidences, needs further investigation.

Mobilized peripheral blood stem cells compared with bone marrow as the stem cell source for unrelated donor allogeneic transplantation with reduced-intensity conditioning in patients with acute myeloid leukemia in complete remission: an analysis from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Reduced-intensity conditioning allogeneic stem cell transplant (RIC-alloSCT) is being increasingly used for patients with acute myelogenous leukemia (AML) with comorbidities. Few published data are currently available regarding for the use of peripheral blood stem cells (PBSCs) compared to bone marrow (BM) in the RIC-alloSCT using unrelated donors (URDs). This retrospective report compared the outcomes of PBSC versus BM RIC-alloSCT. Between 2000 and 2007, 602 patients with AML in complete remission (CR) underwent RIC-alloSCT from URDs with PBSC (508) or BM (94) grafts. Recipient's age was higher in the PBSC versus BM groups 57 (range, 17-77 years) and 51 (range, 17-76 years), respectively (P < .0001). Leukemia features and disease status at RIC-alloSCT were also comparable between the PBSC versus BM groups. Engraftment was achieved in 97% and 96% with BM versus peripheral blood (PB), respectively. Acute graft-versus-host disease (aGVHD) grade >II was significantly higher in the PBSC group: 27% versus 12% in the BM group (P < .002). Similarly, chronic graft-versus-host disease (cGVHD; at 2 years) was somewhat higher in the PBSC group with 43% ± 3% versus 35% ± 6% in the BM group, respectively (P = .04). The 2-year probabilities of leukemia-free survival (LFS) were 46% ± 3% for the PBSC group in comparison to 43% ± 6% for the BM transplant group (P = NS), whereas relapse incidence was significantly higher in the BM versus the PB transplant group: 46% ± 6% versus 32% ± 3%, respectively (P = .014). Non-relapse mortality (NRM) was significantly higher for the PBSC versus the BM group: 28% ± 2% versus 13% ± 4%, respectively (P = .004). In multivariate analysis, after adjustment for differences between both groups, the PBSC group was associated with a higher incidence of aGVHD (grade II-IV; hazard ratio [HR] = 2.33; P = .06), higher NRM (HR = 2.3; P = .015), and a decreased relapse incidence (HR, 0.61; P = .02) with no statistical difference of LFS between the 2 groups (P = .88). In conclusion, our results indicate significantly higher incidence of aGVHD and NRM and a lower incidence of relapse but not statistically different LFS comparing unrelated PBSC to BM grafts after RIC-alloSCT.

Impact of graft-versus-host disease on outcomes after allogeneic hematopoietic cell transplantation for adult T-cell leukemia: a retrospective cohort study

Allogeneic hematopoietic cell transplantation (HCT) is an effective treatment for adult T-cell leukemia (ATL), raising the question about the role of graft-versus-leukemia effect against ATL. In this study, we retrospectively analyzed the effects of acute and chronic graft-versus-host disease (GVHD) on overall survival, disease-associated mortality, and treatment-related mortality among 294 ATL patients who received allogeneic HCT and survived at least 30 days posttransplant with sustained engraftment. Multivariate analyses treating the occurrence of GVHD as a time-varying covariate demonstrated that the development of grade 1-2 acute GVHD was significantly associated with higher overall survival (hazard ratio [HR] for death, 0.65; P = .018) compared with the absence of acute GVHD. Occurrence of either grade 1-2 or grade 3-4 acute GVHD was associated with lower disease-associated mortality compared with the absence of acute GVHD, whereas grade 3-4 acute GVHD was associated with a higher risk for treatment-related mortality (HR, 3.50; P < .001). The development of extensive chronic GVHD was associated with higher treatment-related mortality (HR, 2.75; P = .006) compared with the absence of chronic GVHD. Collectively, these results indicate that the development of mild-to-moderate acute GVHD confers a lower risk of disease progression and a beneficial influence on survival of allografted patients with ATL.

Haploidentical hematopoietic stem cell transplantation in hematologic malignancies with G-CSF mobilized bone marrow plus peripheral blood stem cells grafts without T cell depletion: a single center report of 29 cases

Haploidentical Hematopoietic stem cell transplantation (Haplo-HSCT) has provided an alternative option since virtually all patients have an immediately available donor. Here, we report the results of Haplo-HSCT with granulocyte-colony-stimulating factor (G-CSF) mobilized bone marrow grafts plus peripheral blood stem cells as the grafts without T-cell depletion. Twenty-nine patients with the mean age of 27.27 years (ranging from 15 to 51 years) were enrolled in this study, and 10 cases were in high risk status. The patients received myeloablative preconditioning with or without total body irradiation and acute graft-versus-host disease (GVHD) prophylaxis consisting of basiliximab, cyclosporine A, methotrexate, mycophenolate mofetil and a rabbit anti-thymocyte globulin. All the patients attained successful neutrophil and platelet recovery. The mean times for neutrophil and platelet recovery were 17.1 and 20.9 days, respectively. During the follow-up at a median time of 30.69 months (ranging from 3 to 76 months), nine patients developed aGVHD grade II-IV, including two developed grade III-IV GVHD after donor lymphocyte infusion. The incidence of cGVHD was 48.3%. 13 patients died within the first two years after transplantation, and the total disease-free survival rate longer than 2 years was 55.2%. These results suggest that G-CSF-primed bone marrow plus peripheral blood stem cell grafts are an appropriate stem cell source for Haplo-HSCT and large scale investigations are needed to confirm this protocol.

Allogeneic bone marrow transplantation compared to peripheral blood stem cell transplantation for the treatment of hematologic malignancies: a meta-analysis based on time-to-event data from randomized controlled trials

Controversy remains regarding the transplant outcomes of human leukocyte antigen-identical related bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT) for the treatment of patients with hematological malignancies. To provide an estimate of the effect of BMT and PBSCT on clinical outcomes in patients with hematological malignancies, we conducted a meta-analysis based on time-to-event data from 17 randomized controlled trials. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL), from 1972 through July 2010, and conference proceedings through July 2009 and reference lists, without any language restriction, of randomized trials that compared the transplant outcomes after BMT and PBSCT in patients with hematological malignancies were searched for details. Two independent reviewers extracted the data. The outcomes examined were engraftment, graft-versus-host disease (GVHD), relapse, transplant-related mortality (TRM), leukemia-free-survival (LFS), and overall survival (OS). Compared to PBSCT, BMT had lower neutrophil (HR, 2.08; 95% CI, 1.80 to 2.42; p < 0.00001) and platelet (HR, 2.77; 95% CI, 1.78 to 4.30; p < 0.00001) engraftment. BMT was associated with a significant decrease in the development of grades II-IV (HR, 0.75; 95% CI, 0.63 to 0.90; p = 0.002) and III-IV (HR, 0.63; 95% CI, 0.47 to 0.84; p = 0.001) acute GVHD as well as overall (HR, 0.70; 95% CI, 0.59 to 0.83; p < 0.0001) and extensive (HR, 0.60; 95% CI, 0.39 to 0.91; p = 0.002) chronic GVHD. BMT was associated with a higher incidence of relapse (HR, 1.91; 95% CI, 1.34 to 2.74; p = 0.0004). Comparable TRM (1.08; 95% CI, 0.56 to 2.10; p = 0.81), LFS (HR, 1.04; 95% CI, 0.83 to 1.30; p = 0.73), and OS (HR, 1.06; 95% CI, 0.81 to 1.39; p = 0.65) were demonstrated for both treatments. An inverse linear relationship was observed between the acute GVHD difference (PBSCT minus BMT) and the outcome of OS (p = 0.016). Our meta-analysis suggest that BMT leads to slower hematological recovery, increasing rates of relapse, and a lower risk of GVHD, but no significant difference in LFS and OS. A lower incidence of acute GVHD is associated with a superior OS.