Effect of graft-versus-host disease on the outcome of bone marrow transplantation from an HLA-identical sibling donor using GVHD prophylaxis with cyclosporin A and methotrexate

Clinical effects of tacrolimus blood concentrations early after allogeneic hematopoietic stem cell transplantation

BACKGROUND AIMS

Tacrolimus (TAC) plus short-term methotrexate (stMTX) is used for graft-versus-host disease (GVHD) prophylaxis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). TAC blood concentrations are frequently adjusted to enhance the graft-versus-leukemia/lymphoma effect or attenuate severe GVHD. Limited information is available on the clinical impact of these adjustments and the optimal time to perform them in order to achieve good clinical outcomes.

METHODS

We retrospectively analyzed 211 patients who underwent allo-HSCT at our institutes.

RESULTS

Higher TAC concentrations in week 3 correlated with a significantly higher cumulative incidence of relapse (CIR) (P = 0.03) and lower nonrelapse mortality (P = 0.04). The clinical impact of high TAC concentrations in week 3 on CIR was detected in the refined disease risk index: low/intermediate (P = 0.04) and high (P < 0.01), and conditioning regimens other than cyclophosphamide/total body irradiation and busulfan/cyclophosphamide (P = 0.07). Higher TAC concentrations in week 1 correlated with a lower grade 2-4 acute GVHD rate (P = 0.01). Higher TAC concentrations in weeks 2 and 3 correlated with slightly lower (P = 0.05) and significantly lower (P = 0.02) grade 3-4 acute GVHD rates, respectively. Higher TAC concentrations in weeks 1 and 3 were beneficial for severe acute GVHD in patients with a human leukocyte antigen-matched donor (P = 0.03 and P < 0.01, respectively), not treated with anti-thymocyte globulin (P = 0.02 and P = 0.02, respectively), and receiving three stMTX doses (P = 0.03 and P = 0.02, respectively).

CONCLUSIONS

The clinical impact of TAC concentrations varied according to patient characteristics, including disease malignancy, conditioning regimens, donor sources, and GVHD prophylaxis. These results suggest that TAC management needs to be based on patient profiles.

First complete remission favours haploidentical haematopoietic stem cell transplantation with post-transplant cyclophosphamide over cord blood transplantation in acute lymphoblastic leukaemia

To assess the benefits of HLA-haploidentical haematopoietic stem cell transplantation using post-transplant cyclophosphamide (PTCy-haplo) relative to those of umbilical cord blood (UCB) transplantation in acute lymphoblastic leukaemia (ALL), we analysed 1999 patients (PTCy-haplo, 330; UCB, 1669), using the nationwide Japanese registry. PTCy-haplo was associated with a significantly higher relapse rate, but lower non-relapse mortality, which results in overall survival and disease-free survival, comparable to those of UCB. Among patients in CR1, PTCy-haplo showed a significantly higher survival than UCB regardless of the CD34+ cell dose. Our findings provide valuable insights into the donor selection algorithm in allogeneic HSCT for adult patients with ALL.

Effect of graft-versus-host disease on outcomes of HLA-haploidentical peripheral blood transplantation using post-transplant cyclophophamide

There is limited evidence regarding the association between graft-versus-host disease (GVHD) and reduced relapse in patients who undergo allogeneic hematopoietic stem cell transplantation from haploidentical donors (haplo-HSCT) using post-transplant cyclophosphamide (PTCY). We investigated the association between GVHD and transplant outcomes in 938 patients who received haplo-HSCT using PTCY. Overall survival (OS), relapse rate, and non-relapse mortality (NRM) were evaluated using landmark analysis at the landmark points at 100 and 360 days after HSCT for acute and chronic GVHD, respectively. Grade I-II acute GVHD was not associated with OS (adjusted hazard ratio: 1.15, 95% confidence interval: 0.85-1.57), relapse (1.03, 0.74-1.45) and NRM (1.15, 0.74-1.77). Conversely, grade III-IV acute GVHD was associated with higher NRM (3.16, 1.61-6.19), but no other outcomes. Limited chronic GVHD was not associated with OS (1.11, 0.48-1.95), relapse (1.05, 0.30-3.75) and NRM (1.30, 0.45-3.79). Extensive chronic GVHD was associated with higher NRM (2.40, 1.03-5.57), but no other outcome. In conclusion, any GVHD was not associated with a reduced relapse rate and improved OS, and Grade III-IV acute GVHD and extensive chronic GVHD were associated with higher NRM in patients who received haplo-HSCT using PTCY.

Impact of MRD on clinical outcomes of unrelated hematopoietic stem cell transplantation in patients with Ph+ ALL: A retrospective nationwide study

Measurable residual disease (MRD) status before transplantation has been shown to be a strong prognostic factor in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). However, the outcomes of unrelated hematopoietic stem cell transplantation based on the MRD status have not been fully investigated. In this retrospective study, we compared the outcomes of 715 consecutive adults with Ph+ ALL in complete remission who underwent unrelated cord blood transplantation (UCBT) (single-unit UCBT, n = 232 [4/6, 5/6, and 6/6 HLA match]), HLA-matched unrelated bone marrow transplantation (UBMT; n = 292 [8/8 HLA match]), or HLA-mismatched UBMT (n = 191 [7/8 HLA match]). In the MRD+ cohort, adjusted 3-year leukemia-free survival rates were 59.8%, 38.3%, and 55.5% after UCBT, HLA-matched UBMT, and HLA-mismatched UBMT, respectively. In the MRD- cohort, the corresponding rates were 65.3%, 70.4%, and 69.7%, respectively. The MRD+ HLA-matched UBMT group had a significantly higher risk of relapse than the MRD+ HLA-mismatched UBMT group (hazard ratio [HR] in the MRD+ HLA-mismatched UBMT group, 0.33; 95% confidence interval [CI] 0.15-0.74) and the MRD+ UCBT group (HR in the MRD+ UCBT group, 0.38; 95% CI 0.18-0.83). Furthermore, HLA-matched UBMT had a significant effect of MRD on death (HR 1.87; 95% CI 1.19-2.94), relapse or death (HR 2.24; 95% CI 1.50-3.34), and relapse (HR 3.12; 95% CI 1.75-5.57), while UCBT and HLA-mismatched UBMT did not. In conclusion, our data indicate Ph+ ALL patients with positive MRD may benefit from undergoing UCBT or HLA-mismatched UBMT instead of HLA-matched UBMT to reduce leukemic relapse.

Incidence, clinical presentation, risk factors, outcomes, and biomarkers in de novo late acute GVHD

Late acute graft-versus-host disease (GVHD) is defined as de novo acute GVHD presenting beyond 100 days after allogeneic hematopoietic cell transplantation (HCT) without manifestations of chronic GVHD. Data are limited regarding its characteristics, clinical course, and risk factors because of underrecognition and changes in classification. We evaluated 3542 consecutive adult recipients of first HCTs at 24 Mount Sinai Acute GVHD International Consortium (MAGIC) centers between January 2014 and August 2021 to better describe the clinical evolution and outcomes of late acute GVHD. The cumulative incidence of classic acute GVHD that required systemic treatment was 35.2%, and an additional 5.7% of patients required treatment for late acute GVHD. At the onset of symptoms, late acute GVHD was more severe than classic acute GVHD based on both clinical and MAGIC algorithm probability biomarker parameters and showed a lower overall response rate on day 28. Both clinical and biomarker grading at the time of treatment stratified the risk of nonrelapse mortality (NRM) in patients with classic and late acute GVHD, respectively, but long-term NRM and overall survival did not differ between patients with classic and late acute GVHD. Advanced age, female-to-male sex mismatch, and the use of reduced intensity conditioning were associated with the development of late acute GVHD, whereas the use of posttransplant cyclophosphamide-based GVHD prevention was protective mainly because of shifts in GVHD timing. Because overall outcomes were comparable, our findings, although not definitive, suggest that similar treatment strategies, including eligibility for clinical trials, based solely on clinical presentation at onset are appropriate.

Potential factors for and the prognostic impact of ascites after allogeneic hematopoietic stem cell transplantation

Ascites is sometimes detected after allogeneic hematopoietic stem cell transplantation (allo-HSCT); however, since limited information is currently available, its clinical meaning remains unclear. Therefore, we herein examined potential factors for and the impact of ascites on the prognosis of patients after allo-HSCT at our institutes. Fifty-eight patients developed ascites within 90 days of allo-HSCT (small in 34 (16%), moderate-large in 24 (11%)). A multivariate analysis identified veno-occlusive disease/sinusoidal obstruction syndrome (p = 0.01) and myeloablative conditioning (p = 0.01) as significant potential factors for the development of small ascites. Thrombotic microangiopathy (TMA) (p < 0.01) was a significant potential factor for moderate-large ascites. The incidence of both small and moderate-large ascites correlated with lower overall survival (p = 0.03 for small ascites and p < 0.01 for moderate-large ascites) and higher non-relapse mortality rates (p = 0.03 for small ascites and p < 0.01 for moderate-large ascites). Lower OS and higher NRM rates correlated with the incidence of both small and moderate-large ascites. Further investigation is warranted to establish whether the clinical sign of ascites improves the diagnostic quality of TMA in a large-scale study.

Prophylactic or pre-emptive therapies to prevent relapse after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation is a potent curative treatment for hematological malignancies, but relapse is still a major problem. Donor lymphocyte infusion (DLI) and maintenance therapies after transplantation are promising strategies to reduce the risk of relapse. DLI augments the graft-versus-tumor effect by directly adding allo-reactive donor lymphocytes, and has been used in relapsed patients. In this Progress in Hematology (PIH), we will focus on prophylactic or pre-emptive DLI, including DLI from a haploidentical donor. On the other hand, specific drugs, which are used in maintenance therapies for each disease, kill tumor cells directly and/or immunologically by stimulating immune cells. Maintenance therapies should be started early after transplantation without severe myelosuppression. Molecularly targeted drugs are therefore suitable for use in maintenance therapies, and are reviewed in this PIH. The optimal application of these strategies has not yet been established. However, important evidence regarding their efficacies, adverse events, and effects on immune systems is accumulating, and could help to improve outcomes in allogeneic transplantation.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical relatives in patients with myelodysplastic syndromes and oligoblastic acute myeloid leukemia: a propensity score analysis of a nationwide database

Bone marrow (BM) and granulocyte colony-stimulating factor-mobilized peripheral blood stem cells (PBSC) are used as grafts from HLA-identical-related donors for adults with myelodysplastic syndrome (MDS). To assess the impact of graft sources on post-transplant outcomes in MDS patients, we conducted a retrospective analysis of a nationwide database. A total of 247 and 280 patients underwent transplantation with BM and PBSC, respectively. The inverse probability of treatment weighting (IPTW) methods revealed that overall survival (OS) was comparable between BM and PBSC (P = .129), but PBSC transplantation was associated with worse graft-versus-host disease (GVHD)-free/relapse-free survival (GRFS) (hazard rate [HR], 1.24; 95% confidence intervals [CIs], 1.00-1.53; P = 0.049) and chronic GVHD-free and relapse-free survival (CRFS) (HR, 1.29; 95% CIs, 1.13-1.73; P = 0.002) than BM transplantation. In the propensity score matched cohort (BM, n = 216; PBSC, n = 216), no significant differences were observed in OS and relapse; 3-year OS rates were 64.7% and 60.0% (P = 0.107), while 3-year relapse rates were 27.1% and 23.5% (P = 0.255) in BM and PBSC, respectively. Three-year GRFS rates (36.6% vs. 29.2%; P = 0.006), CRFS rate (37.7% vs. 32.5%; P = 0.003), and non-relapse mortality rates (13.9% vs. 21.1%; P = 0.020) were better in BM than in PBSC. The present study showed that BM transplantation provides a comparable survival benefit with PBSC transplantation and did not identify an enhanced graft-versus-MDS effect to reduce the incidence of relapse in PBSC transplantation.

Effect of graft-versus-host disease on posttransplant outcomes following single cord blood transplantation in comparison to haploidentical transplantation with posttransplant cyclophosphamide for adult acute myeloid leukemia

BACKGROUND

The possibility that human leukocyte antigen (HLA) mismatches could reduce relapse after alternative HLA-mismatched allogeneic hematopoietic cell transplantation (HCT) is an attractive concept for acute myeloid leukemia (AML). However, it remains unclear whether the prognostic effect of graft-versus-host disease (GVHD) on survival differs between single-unit cord blood transplantation (CBT) or haploidentical HCT using posttransplant cyclophosphamide (PTCy-haplo HCT) for AML.

OBJECTIVE

The objective of this retrospective study was to compare the effect of acute and chronic GVHD on posttransplant outcomes between CBT and PTCy-haplo HCT.

STUDY DESIGN

We retrospectively evaluated the effect of acute and chronic GVHD on posttransplant outcomes following CBT and PTCy-haplo HCT in adults with AML (n=1,981) between 2014 and 2020 using a Japanese registry database.

RESULTS

In the univariate analysis, the probability of overall survival was significantly greater in patients who developed grade I-II acute GVHD (P<0.001 by log-rank test) and limited chronic GVHD (P<0.001 by log-rank test) among CBT recipients, but these effects were not significant among PTCy-haplo HCT recipients. In the multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, the effect of grade I-II acute GVHD on reducing overall mortality was significant between CBT and PTCy-haplo HCT (adjusted hazard ratio [HR] for CBT: 0.73, 95% confidence interval [CI]: 0.60-0.87; adjusted HR for PTCy-haplo HCT: 1.07, 95% CI: 0.70-1.64; p for interaction=0.038).

CONCLUSION

Our data demonstrate that grade I-II acute GVHD was associated with a significant improvement in overall mortality in adults with AML receiving CBT but not PTCy-haplo HCT.

Mild Acute Graft-Versus-Host Disease Improves Outcomes After HLA-Haploidentical-Related Donor Transplantation Using Posttransplant Cyclophosphamide and Cord Blood Transplantation

Haploidentical-related donor transplantation using posttransplant cyclophosphamide (PTCy-haplo) and cord blood transplantation (CBT) are valid alternatives for patients with hematological malignancies when HLA-matched donor transplantation (MDT) is unavailable. However, the effects of graft-versus-host disease (GVHD) on outcomes after these transplants have not been fully elucidated. Therefore, we evaluated the effects of acute and chronic GVHD on transplant outcomes after PTCy-haplo transplants and compared them with CBT and MDT. We included a total of 914 adult patients with hematological malignancies in the Kyoto Stem Cell Transplantation Group registry who received PTCy-haplo (N = 120), CBT (N = 402), and MDT (N = 392), and achieved neutrophil engraftment. A multivariate analysis revealed that grade I-II acute GVHD improved of overall survival (OS) after PTCy-haplo [hazard ratio (HR) = 0.39, P = 0.018] and CBT (HR = 0.48, P < 0.001), but not after MDT (HR = 0.80, P = 0.267) compared with patients without acute GVHD. Grade I-II acute GVHD had a trend toward reducing the risk of nonrelapse mortality (NRM) after PTCy-haplo (HR = 0.13, P = 0.060) and this positive effect was significant after CBT (HR = 0.39, P = 0.003). A negative impact of grade III-IV acute GVHD on NRM was observed after CBT and MDT, but not after PTCy-haplo. Limited chronic GVHD had a positive impact on OS after CBT and MDT, but not after PTCy-haplo. In conclusion, mild acute GVHD improved outcomes after PTCy-haplo and CBT, and limited chronic GVHD improved outcomes after CBT and MDT. These data indicated that the effects of GVHD on transplant outcomes depended on transplant platforms.

Deletion of Y-chromosome before allogeneic hematopoietic stem cell transplantation in male recipients with female donors

Del(Y) before transplantation was significantly associated with disease relapse in female-to-male allo-HCT.

A higher incidence of relapse in the del(Y) group might have been caused by attenuation of GVL due to a lack of H-Y antigens.

The graft-versus-leukemia (GVL) effect is one of the curative mechanisms of allogeneic hematopoietic stem cell transplantation (allo-HCT). H-Y antigens, which are encoded by Y chromosome, are important targets of the GVL effect. Thus, deletion of the Y chromosome (del[Y]) might cause the GVL effect to deteriorate in a transplantation involving a female donor and male recipient, although the clinical significance of the del(Y) group remains to be elucidated. In this study, we evaluated adult male patients who underwent allo-HCT between 2010 and 2019 in Japan. There were 155 cases in the del(Y) group and 4149 cases without del(Y) who underwent female-to-male allo-HCT. Del(Y) was significantly associated with inferior overall survival (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.00-1.53; P = .049) and an increased risk of relapse (HR, 1.40; 95% CI, 1.08-1.80; P = .0098) in multivariate analyses. There was no significant difference in nonrelapse mortality between recipients with and without del(Y) (HR, 1.08; 95% CI, 0.769-1.51; P = .67). In contrast, del(Y) was not significantly associated with any clinical outcomes in the cohort of male-to-male allo-HCT. A higher incidence of relapse might have been caused by attenuation of the GVL effect resulting from a lack of H-Y antigens. Because a GVL effect resulting from sex mismatch may not be expected in men with del(Y) who undergo allo-HCT with a female donor, additional post–allo-HCT strategies might be required to prevent disease relapse.

Differential Effect of Graft-versus-Host Disease on Survival in Acute Leukemia according to Donor Type

PURPOSE

The anti-leukemic activity of allogeneic hematopoietic cell transplantation (HCT) depends on both the intensity of conditioning regimen and the strength of the graft-versus-leukemia (GVL) effect. However, it is unclear whether the sensitivity of the GVL effects differs between donor type and graft source.

EXPERIMENTAL DESIGN

We retrospectively evaluated the effect of acute and chronic graft-versus-host disease (GVHD) on transplant outcomes for adults with acute leukemia (n = 6,548) between 2007 and 2017 using a Japanese database. In all analyses, we separately evaluated three distinct cohorts based on donor type [(8/8 allele-matched sibling donor, 8/8 allele-matched unrelated donor, and unrelated single-cord blood (UCB)].

RESULTS

The multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, showed a reductive effect of grade I-II acute GVHD on treatment failure (defined as 1-leukemia-free survival; P < 0.001), overall mortality (OM; P < 0.001), relapse (P < 0.001), and non-relapse mortality (NRM; P < 0.001) in patients receiving from UCB. A reductive effect of limited chronic GVHD on treatment failure (P < 0.001), OM (P < 0.001), and NRM (P < 0.001) was also shown in patients receiving from UCB. However, these effects were not always shown in patients receiving from other donors. The beneficial effects of mild acute and chronic GVHD after UCB transplantation on treatment failure were noted relatively in subgroups of patients with acute myelogenous leukemia and a non-remission status.

CONCLUSIONS

These data suggested that the development of mild GVHD could improve survival after UCB transplantation for acute leukemia.

Allogeneic Hematopoietic Cell Transplantation for Adolescent and Young Adult Patients with Acute Myeloid Leukemia

Limited data exist regarding the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) among adolescent and young adult (AYA) patients with acute myeloid leukemia (AML). Here we analyzed the features and outcomes of AYA patients with AML who had achieved complete remission (CR) and those who had not (non-CR) at allo-HCT. We retrospectively analyzed 2350 AYA patients with AML who underwent allo-HCT with a myeloablative conditioning regimen and who were consecutively enrolled in the Japanese nationwide HCT registry. The difference in overall survival (OS) between younger (age 16 to 29 years) and older AYA (age 30 to 39 years) patients in CR at transplantation was not significant (70.2% versus 71.7% at 3 years; P = .62). Meanwhile, this difference trended toward a statistical significance between younger and older AYA patients in non-CR at transplantation (39.5% versus 34.3% at 3 years; P = .052). In AYA patients in CR and non-CR, the age at transplantation did not affect relapse or nonrelapse mortality (NRM). In AYA patients in CR, no difference in OS was observed between those who received total body irradiation (TBI) and those who did not (71.1% versus 70.5% at 3 years; P = .43). AYA patients who received TBI-based conditioning had a significantly lower relapse rate and higher NRM than those who underwent non-TBI-based conditioning (relapse: 19.8% versus 24.1% at 3 years [P = .047]; NRM: 14.7% versus 11.1% at 3 years [P = .021]). In contrast, among the non-CR patients, there were no differences between the TBI and non-TBI groups with respect to OS (P = .094), relapse (P = .83), and NRM (P = .27). Our data indicate that outcomes may be more favorable in younger AYA patients than in older AYA patients in non-CR at transplantation, and that outcomes of TBI-based conditioning could be comparable to those of non-TBI-based conditioning for AYA patients.

Charlson comorbidity index predicts outcomes of elderly after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia and myelodysplastic syndrome

BACKGROUND/PURPOSE

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the curative therapy for acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS), but advanced age with multiple comorbidities limits the eligibility for allo-HSCT. We conducted a retrospective study to investigate the comorbidities assessments and prognostic factors that predict outcomes for these patients.

METHODS

Clinical data of patients older than 50 years who had received diagnoses of AML or MDS and underwent allo-HSCT were obtained. Information on patient characteristics, including age, gender, allogeneic transplant type, conditioning regimens, Charlson comorbidity index (CCI), and presence of acute graft-versus-host disease (GVHD) or chronic GVHD, were collected and analyzed.

RESULTS

Two hundred fifty-five elderly patients with a median age at allo-HSCT of 57 years were included. The significant prognostic factors associated with worse overall survival (OS) were CCI ≥3 (hazard ratio: 1.88) and grade III-IV acute GVHD (3.18). Similar findings were noted in the non-relapse mortality analysis. To investigate the effects of chronic GVHD on patient outcomes, OS analysis was performed for those with survival >100 days after transplantation. The results revealed CCI ≥3 (1.88) and grade III-IV acute GVHD (2.73) remained poor prognostic factors for OS, whereas mild chronic GVHD (0.43) was associated with better OS.

CONCLUSION

This cohort study suggests that CCI ≥3 predicts poor outcomes, primarily due to a higher NRM risk. Careful management of GVHD after transplantation could improve outcomes in elderly patients with AML or MDS after allo-HSCT.

Comparison of Tacrolimus and Cyclosporine Combined With Methotrexate for Graft Versus Host Disease Prophylaxis After Allogeneic Hematopoietic Cell Transplantation

BACKGROUND

After patients receive hematopoietic stem cell transplantation (HSCT), both cyclosporine (CsA) and tacrolimus (TAC) in combination with methotrexate (MTX) are recommended as the standard prophylaxis strategy for graft versus host disease (GVHD) by the European Group of Blood and Marrow Transplantation. However, the advantage of TAC combined with MTX lacks conclusive evidence.

METHODS

We searched online databases for studies comparing CsA + MTX and TAC + MTX in patients who received HSCT. The odds ratio (OR) and 95% confidence interval (CI) were applied to compare the pooled data.

RESULTS

We found a significant reduction in the grade II to IV acute GVHD (aGVHD) rate (OR, 0.42; CI, 0.28-0.61; P < 0.00001), grade III to IV aGVHD rate (OR, 0.59; CI, 0.38-0.92; P = 0.02), chronic GVHD rate (OR, 0.79; CI, 0.62-1.00; P = 0.05), and nonrelapse mortality rate (OR, 0.62; CI, 0.40-0.95; P = 0.03) and an increase in the overall survival (OS) rate (only in those received from unrelated donor) (OR, 1.30; CI, 1.15-1.48; P < 0.0001) in the TAC + MTX group. Similar outcomes occurred for the relapse rate and disease-free survival rate in both groups.

CONCLUSIONS

TAC + MTX has a superior effect in the prevention of aGVHD in patients who received HSCT and further prolongs the OS in patients who received from unrelated donor transplants. CsA + MTX prolongs the OS in patients who received HSCT from HLA-identical sibling donors. The leukemic relapse and disease-free survival rate were not different between the 2 regimens. Thus, we conclude that TAC + MTX was superior to CsA + MTX, especially for HSCT patients with nonmalignant disorders. Further studies are still required to evaluate the effect of TAC or CsA combined with other suppressors in the treatment regimen following HSCT.

Effects of Acute and Chronic Graft-versus-myelodysplastic Syndrome on Long-term Outcomes Following Allogeneic Hematopoietic Cell Transplantation

PURPOSE

Potent graft-versus-tumor (GVT) effects associated with graft-versus-host disease (GVHD) might be dependent on hematologic disease type and status. However, the data regarding the impact of GVHD on transplant outcomes for patients with myelodysplastic syndrome (MDS) are limited.

EXPERIMENTAL DESIGN

We retrospectively evaluated the impact of acute and chronic GVHD on transplant outcomes for a large cohort of adult patients with a low-risk (n = 1,193) and high-risk (n = 1,926) MDS treated by first allogeneic hematopoietic cell transplantation between 2001 and 2017.

RESULTS

The multivariate analysis, in which development of GVHD was treated as a time-dependent covariate, showed that acute and chronic GVHD at any grade or severity did not improve overall mortality, relapse, or nonrelapse mortality (NRM) in low-risk MDS. For patients with high-risk MDS, development of limited chronic GVHD was significantly associated with lower overall mortality [HR, 0.66; 95% confidence interval (CI), 0.50-0.86; P = 0.002]. This is probably due to that the reduced risk of relapse with grade III-IV acute GVHD (HR, 0.41; 95% CI, 0.25-0.65; P = 0.0002), or limited (HR, 0.57; 95% CI, 0.39-0.83; P = 0.003) or extensive (HR, 0.56; 95% CI, 0.41-0.77; P = 0.0004) chronic GVHD was offset by increased NRM with grade III-IV acute GVHD or extensive chronic GVHD in high-risk MDS.

CONCLUSIONS

These data demonstrated a survival benefit of the graft-versus-MDS effect is present only in high-risk MDS patients with limited chronic GVHD.See related commentary by Eckel and Deeg, p. 6404.

Soluble Interleukin-2 Receptor Index Predicts Outcomes After Cord Blood Transplantation

BACKGROUND

Our previous study demonstrated that the soluble interleukin-2 receptor (sIL-2R) index, defined as the ratio of serum sIL-2R levels at neutrophil engraftment to that before conditioning, is a biomarker that can predict acute graft-vs-host disease (GVHD) after unrelated bone marrow transplantation. In the present study, we evaluated the significance of the sIL-2R index among patients who underwent cord blood transplantation (CBT).

METHODS

We retrospectively analyzed 31 patients who underwent single-unit CBT as their first transplantation for hematologic malignancies.

RESULTS

The median sIL-2R index was 4.2. The cumulative incidence of grade II to IV acute GVHD was not associated with the sIL-2R index. However, the cumulative incidence of relapse at 3 years after transplantation was significantly lower, with an sIL-2R index ≥ 3.7 than with an index < 3.7 (12.8% vs 50.0%; P = .04). As a result, the probability of overall survival at 3 years after transplantation was significantly higher in the former group than in the latter (79.8% vs 20.0%; P < .01). Only the dose of corticosteroid administered in the pre-engraftment period influenced the sIL-2 index.

CONCLUSION

The sIL-2R index can predict the incidence of relapse and probability of survival after CBT, possibly reflecting a graft-vs-leukemia effect.

Effect of graft-versus-host disease on outcomes after pediatric single cord blood transplantation

The effect of GVHD on transplant outcomes after unrelated cord blood transplantation (UCBT) is not yet fully understood. Pediatric patients aged 0-15 years with acute leukemia or myelodysplastic syndrome who underwent their first UCBT (n = 740) were selected from the Japanese registry. Fifty percent of the patients received a UCB unit containing more than 5.0 × 10⁷/kg total nucleated cells. The occurrence of grade III-IV acute GVHD was associated with a higher risk of non-relapse mortality (NRM, hazard ratio [HR] 4.07, P < 0.001) compared with no acute GVHD. Grade I-II acute GVHD was not associated with NRM. The occurrence of grade I-II or grade III-IV acute GVHD was not associated with a relapse risk. These findings showed that grade I-II acute GVHD carried no survival benefit and grade III-IV acute GVHD had an adverse effect (HR 1.68, P = 0.007). The occurrence of limited chronic GVHD was associated with a low risk of overall mortality (HR 0.60, P = 0.045). Severe acute GVHD should be prevented because of its association with high overall mortality and NRM in pediatric single UCBT. Mild acute GVHD provides no overall benefit. Mild chronic GVHD may be beneficial for survival.

Impact of graft-versus-host disease and graft-versus-leukemia effect based on minimal residual disease in Philadelphia chromosome-positive acute lymphoblastic leukemia

The impacts of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect might differ depending on minimal residual disease (MRD). Therefore, we examined 1,022 recipients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) in first complete remission. MRD status at HSCT was negative in 791 (77·4%) and positive in 231 (22·6%). The impact of GVHD as a time-dependent covariate on transplant outcomes were analyzed while adjusting for other possible variables. Mild acute GVHD [hazard ratio (HR), 0·90; 95% confidence interval (CI), 0·70-1·16; P = 0·901] and chronic GVHD (HR, 0·82, 95% CI, 0·58-1·14; P = 0·238) were not significantly associated with overall mortality, whereas severe acute GVHD (HR, 2·26, 95% CI, 1·64-3·11; P < 0·001) resulted in inferior overall survival due to high non-relapse mortality. Moreover, even in the subgroup analyses stratified according to MRD status, acute and chronic GVHD were not significantly associated with better overall survival. Therefore, less intensive GVHD prophylaxis to achieve a GVL effect is not recommended for Ph-positive ALL.

European Group for Blood and Marrow Transplantation score correlates with outcomes of older patients undergoing allogeneic hematopoietic stem cell transplantation

BACKGROUND

Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are hematological diseases predominantly occurring in older patients. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the curative therapy for refractory AML or high-risk MDS, old age is often a hurdle to the procedure. We conducted a retrospective study to analyze the prognostic factors predicting outcomes of older patients undergoing allo-HSCT for acute leukemia and MDS.

METHODS

We collected data from patients diagnosed with acute leukemia or MDS, who underwent allo-HSCT at >50 years of age and reviewed clinical characteristics, including age, sex, underlying disease, European Group for Blood and Bone Marrow Transplantation (EBMT) risk score, and presence of acute graft-versus-host disease (aGVHD) or chronic GVHD (cGVHD). The Cox proportional hazard model was adopted to explore the independent prognostic factors for overall survival (OS), progression-free survival (PFS), and non-relapse mortality (NRM).

RESULTS

A total of 85 older patients were included, with the median age at allo-HSCT being 55 years. The significant prognostic factors for worse OS or PFS were an EBMT risk score > 3 and grade III-IV aGVHD, while patients with moderate to severe cGVHD would have better OS or PFS. Interestingly, it is not cGVHD but grade III-IV aGVHD that significantly correlated with NRM.

CONCLUSION

This cohort study suggests that an EBMT risk score >3 and grade III-IV aGVHD predict poor outcomes, and careful management of GVHD may allow better survival for older patients undergoing allo-HSCT.

Impact of graft-versus-host disease on the clinical outcome of allogeneic hematopoietic stem cell transplantation for non-malignant diseases

The impact of acute and chronic graft-versus-host disease (GVHD) on clinical outcomes was retrospectively analyzed in 960 patients with non-malignant diseases (NMD) who underwent a first allogeneic hematopoietic stem cell transplantation (HSCT). Grade III-IV acute GVHD (but not grade I-II) was significantly associated with a lower rate of overall survival (OS), and higher non-relapse mortality (NRM) than that seen in patients without acute GVHD. Extensive (but not limited) GVHD was significantly associated with a lower OS rate and higher NRM than that seen in patients without chronic GVHD. Any grade of acute (but not chronic) GVHD was significantly associated with a lower incidence of relapse and a lower proportion of patients requiring a second HSCT or donor lymphocyte infusion for graft failure or mixed chimerism, but its impact on OS was almost negligible. Acute GVHD was significantly associated with lower OS rates in all disease groups, whereas chronic GVHD was significantly associated with lower OS rates in the primary immunodeficiency and histiocytosis groups. In conclusion, acute and chronic GVHD, even if mild, was associated with reduced OS in patients receiving HSCT for NMD and effective strategies should, therefore, be implemented to minimize GVHD.

Graft-versus-MDS effect after unrelated cord blood transplantation: a retrospective analysis of 752 patients registered at the Japanese Data Center for Hematopoietic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation is the sole curative therapy for myelodysplastic syndrome (MDS). However, there is concern regarding graft failure and relapse in patients who undergo cord blood transplantation (CBT). We conducted a retrospective study of the CBT outcomes in MDS patients using the Japanese Data Center for Hematopoietic Cell Transplantation database. Seven hundred fifty-two de novo MDS patients of ≥18 years of age (median, 58 years) undergoing their first CBT between 2001 and 2015 were examined. Two-thirds of the patients were male, and were RAEB. The cumulative incidences of neutrophil and platelet engraftment at day 100 were 77 and 59%, respectively. The 3-year overall survival (OS) was 41% and the median survival of the patients was 1.25 years. A multivariate analysis of pre-transplant variables showed that the age, gender, cytogenetic subgroups, number of RBC transfusions, HCT-CI and year of CBT significantly influenced the outcome. The cumulative incidence of acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) was 32 and 21%, respectively. A survival benefit was observed in patients who developed cGVHD, but not aGVHD. Our results suggest that CBT is an acceptable alternative graft and that a graft-versus-MDS effect can be expected, especially in patients who develop cGVHD.

Development of Pre-Engraftment Syndrome, but Not Acute Graft-versus-Host Disease, Reduces Relapse Rate of Acute Myelogenous Leukemia after Single Cord Blood Transplantation

The different effects of pre-engraftment syndrome (PES) and acute graft-versus-host disease (aGVHD) on outcomes after cord blood transplantation (CBT) are unclear. We retrospectively evaluated the impact of PES and aGVHD on relapse and survival after single-unit CBT in 138 adult patients with hematologic malignancies at our institution between 2004 and 2016. Multivariate analysis demonstrated that development of grade III-IV aGVHD, particularly with gut or liver involvement, significantly contributed to higher nonrelapse mortality (P < .001), but PES and grade II-IV aGVHD did not. In subgroup analyses of underlying disease type, the development of PES had a significant effect on decreased relapse (P = .032) and better disease-free survival (DFS) (P = .046) in patients with acute myelogenous leukemia (AML). These data suggest that PES is associated with a reduced relapse rate and better DFS in AML, indicating that the early immune reaction before neutrophil engraftment may provide a unique graft-versus-leukemia effect after single-unit CBT.

Single- Versus Double-Unit Umbilical Cord Blood Transplantation for Hematologic Diseases: A Systematic Review

Controversial results exist regarding the clinical benefits of single- vs double-unit umbilical cord blood transplantation (UCBT) in patients with hematologic diseases. A systematic review was conducted to evaluate this issue. The PubMed, Embase, and Cochrane Library databases were searched up to May 2018. A total of 25 studies including 6571 recipients were identified. Although double-unit UCB contained higher doses of total nucleated cells and CD34⁺ cells, it offered no advantages over single-unit UCB in terms of hematologic recovery, including the rate and speed of neutrophil and platelet engraftment. Double-unit UCBT was associated with higher incidences of grades II-IV acute and extensive chronic graft-vs-host disease, accompanied by a lower relapse incidence, which may be attributed to a graft-vs-graft effect induced by double-unit UCB. However, transplant-related mortality, disease-free survival, and overall survival were comparable between single- and double-unit UCBT. Although double-unit UCBT confers no clinical advantages over single-unit UCBT, certain patients, such as those at high risk of relapse, might benefit from double-unit UCBT, a possibility that needs to be clarified in future randomized trials.

Late-phase human herpesvirus 6B reactivation in hematopoietic stem cell transplant recipients

BACKGROUND

We sought to determine whether late-phase human herpesvirus 6B (HHV-6B) infection in hematopoietic stem cell transplant (HSCT) recipients was associated with serious outcomes and mortality.

METHODS

The occurrence and course of HHV-6B infection was monitored for at least 60 days after transplant using virus isolation and real-time polymerase chain reaction. Risk factors for late-phase HHV-6B infection were examined, and the propensity score was calculated with significant risk factors. The inverse probability-weighted multivariable logistic regression analysis was performed to estimate odds ratios (ORs) and the 95% confidence intervals (95% CI) for mortality.

RESULTS

Late-phase HHV-6B infection was observed in 12/89 (13.5%) of the HSCT recipients. Older age (OR: 10.3, 95% CI: 2.1/72.9, P = .0027), hematologic malignancy (OR: 10.3, 95% CI: 1.8/97.1, P = .0063), unrelated donor transplantation (OR: 5.3, 95% CI: 1.1/36.0, P = .0345), and sex-mismatched donor transplantation (OR: 6.3, 95% CI: 1.4/39.5, P = .0149) were identified as risk factors for late-phase HHV-6B infection. Fifteen subjects died (17%). Inverse probability-weighted multivariable logistic model analysis revealed that late-phase HHV-6B infection was an independent risk factor for mortality (OR: 4.2, 95% CI: 1.7/11.0, P = .0012). Among 5 of the fatal cases of late-phase HHV-6B infection, viral infection might be associated with severe clinical manifestations.

CONCLUSION

Late-phase HHV-6B infection in HSCT recipients was associated with worse outcomes. The full spectrum of clinical features of the infection has not been fully elucidated, and therefore, recipients with high-risk factors for late-phase HHV-6B infection should be carefully monitored.

Impact of Human Leukocyte Antigen Allele Mismatch in Unrelated Bone Marrow Transplantation with Reduced-Intensity Conditioning Regimen

The impact of HLA mismatch in hematopoietic stem cell transplantation with reduced-intensity conditioning (RIC) has not been fully examined. We analyzed a total of 1130 cases to examine the effects of HLA allele mismatch in unrelated bone marrow transplantation (BMT) with RIC in the Japan Marrow Donor Program registry cohort. Compared with HLA 8/8-allele match (n = 720, 8/8 match), both 1 (n = 295, 7/8 match) and 2 allele mismatches (n = 115, 6/8 match) were associated with significant reduction of overall survival (OS) (hazard ratio [HR],  1.34; P = .0024 and HR, 1.33; P = .035 for 7/8 and 6/8 match, respectively). The incidence of grades 2 to 4 acute graft-versus-host disease (aGVHD) increased with increasing number of mismatched alleles (HR, 1.36 and HR, 2.08 for 7/8 and 6/8 match, respectively). Nonrelapse mortality showed a similar tendency to aGVHD (HR, 1.35 for 7/8 and HR, 1.63 for 6/8). One-allele mismatches at the HLA-A or -B and HLA-C loci were significantly associated with inferior OS compared with 8/8 match (HR, 1.64 for A or B mismatch and HR, 1.41 for C mismatch), whereas HLA-DRB1 allele mismatch was not (HR, 1.16; P = .30). However, the effect of HLA-A or -B and -C mismatch on OS was not observed in those who received RIC BMT since 2010, in contrast to recipients before 2010. These results suggested that in unrelated RIC BMT, 1-allele mismatch is associated with poorer outcome, and the impact of HLA mismatch may differ depending on the HLA locus, although these HLA mismatch effects may be different in recent cases.

Impact of graft-versus-host disease on outcomes after unrelated cord blood transplantation

The effect of graft-versus-host disease (GVHD) on transplant outcomes after unrelated cord blood transplantation (UCBT) has not been fully elucidated. We analyzed the impact of acute and chronic GVHD on outcomes in adult patients with acute leukemia or myelodysplastic syndrome who underwent their first UCBT (n=2558). The effect of GVHD on outcomes was analyzed after adjusting for other significant variables. The occurrence of GVHD was treated as a time-dependent covariate. The occurrence of grade 1-2 or 3-4 acute GVHD was significantly associated with a lower relapse rate. Grade 3-4 acute GVHD was associated with a higher risk of non-relapse and overall mortality than no acute GVHD, whereas grade 1-2 acute GVHD was associated with a lower risk of non-relapse and overall mortality than no acute GVHD. Limited or extensive chronic GVHD was significantly associated with a lower relapse rate. Limited chronic GVHD was associated with a lower overall and non-relapse mortality than no chronic GVHD. In conclusion, mild acute or chronic GVHD was associated not only with a low risk of relapse but also with a low risk of non-relapse mortality, and provides a survival benefit in UCBT.

Three-dimensional structure discrepancy between HLA alleles for effective prediction of aGVHD severity and optimal selection of recipient-donor pairs: a proof-of-concept study

The optimal selection of recipient-donor pair and accurate prediction of acute graft-versus-host disease (aGVHD) severity are always the two most crucial works in allogeneic hematopoietic stem cell transplantation (allo-HSCT), which currently rests mostly with HLA compatibility, the most polymorphic loci in the human genome, in clinic. Thus, there is an urgent need for a rapid and reliable quantitative system for optimal recipient-donor pairs selection and accurate prediction of aGVHD severity prior to allo-HSCT. For these reasons, we have developed a new selection/prediction system for optimal recipient-donor selection and effective prediction of aGVHD severity based on HLA three-dimensional (3D) structure modeling (HLA-TDSM) discrepancy, and applied this system in a pilot randomized clinical allo-HSCT study. The 37 patient-donor pairs in the study were typed at low- and high-resolution levels for HLA-A/-B/-DRB1/-DQB1 loci. HLA-TDSM system covering the 10000 alleles in HLA class I and II consists of the revised local and coordinate root-mean-square deviation (RMSD) values for each locus. Its accuracy and reliability were confirmed using stably transfected Hmy2.CIR–HLA-B cells, TCR Vβ gene scan, and antigen-specific alloreactive cytotoxic lymphocytes. Based on the preliminary results, we theoretically defined all HLA acceptable versus unacceptable mismatched alleles. More importantly, HLA-TDSM enabled a successful retrospective verification and prospective prediction for aGVHD severity in a pilot randomized clinical allo-HSCT study of 32 recipient-donor transplant pairs. There was a strong direct correlation between single/total revised RMSD and aGVHD severity (92% in retrospective group vs 95% in prospective group). These results seem to be closely related to the 3D structure discrepancy of mismatched HLA-alleles, but not the number or loci of mismatched HLA-alleles. Our data first provide the proof-of-concept that HLA-TDSM is essential for optimal selection of recipient-donor pairs and effective prediction of aGVHD severity before allo-HSCT.

Methotrexate for the Treatment of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Glucocorticoids have been the primary treatment of graft-versus-host disease (GVHD) over the past decade. Complete responses to steroid therapy are usually expected in almost one-third of aGVHD cases and partial response is anticipated in another one-third of patients. However, for those patients not responding to corticosteroid treatment, there is no standard second-line therapy for acute or chronic GVHD. Methotrexate (MTX) for treatment of steroid refractory GVHD has been evaluated in a number of studies. Results from peer-reviewed original articles were identified and the pooled data analyzed. Despite several limitations in data collection and analysis, weekly administration of methotrexate at a median dose of 7.5 mg/m² seems to be safe with minimal toxicities in the context of both aGVHD and cGVHD treatments. The observed overall response (OR) in patients with aGVHD to MTX treatment in the published studies was 69.9%, with complete response (CR) in 59.2% and PR in 10.6%. In cGVHD the OR was 77.6%, with CR reported in 49.6% and PR in 28% of patients. Predictors of better responses were lower grade GVHD, cutaneous involvement, and isolated organ involvement. MTX as a steroid sparing agent might reduce long-term complications and improve the quality of life of GVHD affected individuals.

Recipient PTPN22 -1123 C/C genotype predicts acute graft-versus-host disease after HLA fully matched unrelated bone marrow transplantation for hematologic malignancies

PTPN22 is a critical negative regulator of T cell responses. Its promoter gene variant (rs2488457, -1123G>C) has been reported to be associated with autoimmune diseases. This study analyzed the impact of the PTPN22 variant on transplantation outcomes in a cohort of 663 patients who underwent unrelated HLA-matched bone marrow transplantation (BMT) for hematologic malignancies through the Japan Marrow Donor Program. The recipient C/C genotype versus the recipient G/G genotype resulted in a lower incidence of grade II-IV acute graft-versus-host disease (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.29-0.85; P = .01), as well as a higher incidence of relapse (HR, 1.78; 95% CI, 1.10-2.90; P = .02), as demonstrated on multivariate analysis. In patients with high-risk disease, the recipient C/C genotype was associated with significantly worse overall survival rates than the recipient G/G genotype (HR, 1.60; 95% CI, 1.02-2.51; P = .04), whereas this effect was absent in patients with standard-risk disease. In addition, the donor G/C genotype was associated with a lower incidence of relapse (HR, 0.58; 95% CI, 0.40-0.85), which did not influence survival. Our findings suggest that PTPN22 genotyping could be useful in predicting prognoses and creating therapeutic strategies for improving the final outcomes of allogeneic BMT.

Chronic GVHD is associated with lower relapse risk irrespective of stem cell source among patients receiving transplantation from unrelated donors

Chronic GVHD (cGVHD) has been associated with reduced risk of relapse after allo-SCT for onco-hematological disease due to a graft-vs-malignancy effect. Here we retrospectively analyzed a series of 802 adult patients transplanted from unrelated donors and found that cGVHD was associated with significantly lower relapse and that the limited form was associated with a survival advantage: hazard ratio for OS=0.63 (0.46-0.87); P=0.004; this was due to combination of relapse reduction and similar non-relapse mortality with respect to patients without cGVHD. Importantly, the graft-vs-malignancy effect observed here did not differ when PBSC or BM were used as stem cell source, thus suggesting that the protective effect of limited cGVHD is similar after PBSC- or BM-based transplantation. These findings could have practical implications and suggest no qualitative difference between cGVHD occurring after transplantation performed with different stem cell sources.

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.

Successful treatment of lymphoid blastic crisis in chronic myelogenous leukemia with the additional bcr/abl transcript using imatinib-combined chemotherapy and high-dose chemotherapy with allogeneic bone marrow stem cell transplantation

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder characterized by the presence of the Philadelphia chromosome. Although the major BCR/ABL transcript is present in majority of CML patients, the minor BCR/ABL transcript is rarely reported as an additional chromosomal abnormality related to the progression of CML. We describe the case of a 37-year-old woman who had CML and pain in the extremities. She was diagnosed with lymphoid blast crisis of CML on the basis of the following findings: presence of promyelocytes, myelocytes, and metamyelocytes in peripheral blood smear; detection of major and minor BCR/ABL transcripts by polymerase chain reaction analysis; proliferation of lymphoblastic cells with abnormal B-cell phenotype; and aberrant expression of myeloid antigens in the bone marrow. The patient underwent one course of idarubicin and cytosine arabinose therapy combined with imatinib followed by daunorubicin/cyclophosphamide plus vincristine and prednisone/L: -asparaginase (DNR/COP/L: -ASP) therapy, high-dose cytosine arabinose, and CHOP therapy (cyclophosphamide, doxorubicin, vincristine, and prednisolone). Subsequently, the patient underwent high-dose chemotherapy (total body irradiation and cyclophosphamide) followed by allogeneic bone marrow stem cell transplantation from a human leukocyte antigen (HLA)-matched unrelated donor. After these treatments, the patient was disease-free for 19 months. Our case suggests that these treatments may be feasible, safe, and effective for the treatment of patients with blast crisis CML expressing the minor BCR/ABL transcript.

Impact on relapse of corticosteroid therapy after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia

Corticosteroids are often used following allogeneic hematopoietic stem cell transplantation (HSCT) to control complications such as graft-versus-host disease (GVHD). However, there is some concern that corticosteroids may suppress the graft-versus-leukemia effect and increase leukemia relapse. To evaluate the effect of corticosteroids on relapse, we analyzed 112 adult patients who received their first allogeneic HSCT for acute myeloid leukemia at our institution between 1997 and 2007. Fifty-seven patients (50.9%) received corticosteroid therapy. Patients who had corticosteroid therapy included higher proportion of patients who developed GVHD. In multivariate analysis, with corticosteroid administration entered as a time-dependent covariate, corticosteroid administration was not a risk factor for relapse (p = 1.00, hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.53-1.88), but it was associated with higher non-relapse mortality (NRM) (p < 0.001, HR 55.5, 95% CI 7.42-416) and lower overall survival (p < 0.001, HR 2.68, 95% CI 1.56-4.61). The higher NRM associated with corticosteroid administration was mainly due to the increased deaths caused by the complications themselves, which required corticosteroid therapy. The findings of this study indicate the importance of controlling complications after allogeneic HSCT. The strategy of refraining from indispensable corticosteroid therapy because of the excessive concerns about relapse should be avoided.

DC homeostasis in hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation is an important experimental tool and therapeutic modality. Its efficacy and toxicity are both linked to a GvH reaction that is initiated by donor T cells recognizing recipient APC, of which DC are the most potent. In most tissues recipient DC are replaced after transplantation because they turnover rapidly from BM-derived precursors. However, in a number of sites, notably the skin, recipient DC may persist and even self-renew for many months after transplantation. Understanding the homeostasis of different APC populations and how they are related to the induction of alloreactivity may help to improve the therapeutic benefit of transplantation.

Myeloablative allogeneic hematopoietic stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia in adults: significant roles of total body irradiation and chronic graft-versus-host disease

Disease-free survival in Philadelphia chromosome-positive ALL (Ph + ALL) is very poor, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently considered the only procedure with curative potential. To identify factors affecting transplant outcome, we analyzed the data from 197 Ph + ALL patients aged 16 years or older who had undergone allo-HSCT. The 5-year survival rates were 34% for patients in first complete remission (CR), 21% for those in second or subsequent CR, and 9% for those with active disease (P < 0.0001). Multivariate analysis showed four pre-transplant factors as significantly associated with better survival: younger age, CR at the time of transplantation, conditioning with total body irradiation, and HLA-identical sibling donor (P < 0.0001, P < 0.0001, P = 0.0301, P = 0.0412, respectively). Severe acute GVHD increased the risk of treatment-related mortality (TRM) without diminishing the risk of relapse, whereas chronic GVHD reduced the risk of relapse without increasing the risk of TRM. Thus, patients who developed extensive chronic GVHD had better survivals (P = 0.0217), and those who developed grade III-IV acute GVHD had worse survivals (P = 0.0023) than did the others.