Female donors contribute to a selective graft-versus-leukemia effect in male recipients of HLA-matched, related hematopoietic stem cell transplants

Effects of female bone marrow transplantation on male reproductive organs

Graft-versus-host disease (GVHD), an adverse effect after bone marrow transplantation (BMT), may affect male reproductive function. It is hypothesized that a sex-mismatched BMT induces GVHD in male reproductive organs because female immune cells are not immunologically tolerant to specific antigens of the male organs. However, this hypothesis has not been experimentally verified using male (M) recipient animals following BMT from the female (F) donors. Therefore, the aim of the present study is to examine whether the female BMT to males (F→M group) induces some GVHD reactions in the testis and the other male reproductive organs. The results showed that no inflammation was found in recipients of the male BMT to males (M→M group), whereas significant inflammatory cell responses lasting for at least 4 months were induced in testis, epididymis, prostate and preputial gland in some mice of F→M group. The most severe lesion was found in the preputial gland, in which lymphocytic inflammation was accompanied by loss of glandular acini, thickening of the interstitum and increased cytokines such as TNF-α and IFN-γ. Western blot analyses revealed that sera from the F→M group reacted with various antigens of the male reproductive organs. These results indicate that transplanted female immune cells may recognize the male reproductive organs as immunologically foreign ones and induce chronic GVHD, which may affect male reproductive function.

Influence of donor-recipient sex on engraftment of normal and leukemia stem cells in xenotransplantation

Immunodeficient mouse models are widely used for the assessment of human normal and leukemic stem cells. Despite the advancements over the years, reproducibility, as well as the differences in the engraftment of human cells in recipient mice remains to be fully resolved. Here, we used various immunodeficient mouse models to characterize the effect of donor-recipient sex on the engraftment of the human leukemic and healthy cells. Donor human cells and recipient immunodeficient mice demonstrate sex-specific engraftment levels with significant differences observed in the lineage output of normal CD34+ hematopoietic stem and progenitor cells upon xenotransplantation. Intriguingly, human female donor cells display heightened sensitivity to the recipient mice's gender, influencing their proliferation and resulting in significantly increased engraftment in female recipient mice. Our study underscores the intricate interplay taking place between donor and recipient characteristics, shedding light on important considerations for future studies, particularly in the context of pre-clinical research.

The impact of regulatory T cells on the graft-versus-leukemia effect

Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) is the only curative therapy for many hematologic malignancies, whereby the Graft-versus-Leukemia (GVL) effect plays a pivotal role in controlling relapse. However, the success of GVL is hindered by Graft-versus-Host Disease (GVHD), where donor T cells attack healthy tissues in the recipient. The ability of natural regulatory T cells (Treg) to suppress immune responses has been exploited as a therapeutical option against GVHD. Still, it is crucial to evaluate if the ability of Treg to suppress GVHD does not compromise the benefits of GVL. Initial studies in animal models suggest that Treg can attenuate GVHD while preserving GVL, but results vary according to tumor type. Human trials using Treg as GVHD prophylaxis or treatment show promising results, emphasizing the importance of infusion timing and Treg/Tcon ratios. In this review, we discuss strategies that can be used aiming to enhance GVL post-Treg infusion and the proposed mechanisms for the maintenance of the GVL effect upon the adoptive Treg transfer. In order to optimize the therapeutic outcomes of Treg administration in allo-HSCT, future efforts should focus on refining Treg sources for infusion and evaluating their specificity for antigens mediating GVHD while preserving GVL responses.

Prediction model for EBV infection following HLA haploidentical matched hematopoietic stem cell transplantation

AIMS

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for hematological malignancies. However, viral infections, particularly EBV infection, frequently occur following allo-HSCT and can result in multi-tissue and organ damage. Due to the lack of effective antiviral drugs, these infections can even progress to post-transplant lymphoproliferative disorders (PTLD), thereby impacting the prognosis. In light of this, our objective is to develop a prediction model for EBV infection following allo-HSCT.

METHODS

A total of 466 patients who underwent haploidentical hematopoietic stem cell transplantation (haplo-HSCT) between September 2019 and December 2020 were included in this study. The patients were divided into a development cohort and a validation cohort based on the timing of their transplantation. Our aim was to develop and validate a grading scale using these cohorts to predict the risk of EBV infection within the first year after haplo-HSCT. Additionally, single-cell RNA sequencing (sc-RNAseq) data from the bone marrow of healthy donors were utilized to assess the impact of age on immune cells and viral infection.

RESULTS

In the multivariate logistic regression model, four predictors were retained: donor age, female-to-male transplant, graft MNC (mononuclear cell) dose, and CD8 dose. Based on these predictors, an EBV reactivation predicting score system was constructed. The scoring system demonstrated good calibration in both the derivation and validation cohorts, as confirmed by the Hosmer-Lemeshow test (p > 0.05). The scoring system also exhibited favorable discriminative ability, as indicated by the C statistics of 0.72 in the derivation cohort and 0.60 in the validation cohort. Furthermore, the clinical efficacy of the scoring system was evaluated using Kaplan-Meier curves based on risk ratings. The results showed significant differences in EBV reactivation rates between different risk groups, with p-values less than 0.001 in both the derivation and validation cohorts, indicating robust clinical utility. The analysis of sc-RNAseq data from the bone marrow of healthy donors revealed that older age had a profound impact on the quantity and quality of immune subsets. Functional enrichment analysis highlighted that older age was associated with a higher risk of infection. Specifically, CD8 + T cells from older individuals showed enrichment in the pathway of "viral carcinogenesis", while older CD14 + monocytes exhibited enrichment in the pathway of "regulation of viral entry into host cell." These findings suggest that older age may contribute to an increased susceptibility to viral infections, as evidenced by the altered immune profiles observed in the sc-RNAseq data.

CONCLUSION

Overall, these results demonstrate the development and validation of an effective scoring system for predicting EBV reactivation after haplo-HSCT, and provide insights into the impact of age on immune subsets and viral infection susceptibility based on sc-RNAseq analysis of healthy donors' bone marrow.

Determining the predictive impact of donor parity on the outcomes of human leukocyte antigen matched hematopoietic stem cell transplants: a retrospective, single-center study

Introduction

Donor choosing remains to play a pivotal role in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Numerous criteria beyond HLA compatibility impact the selection of a suitable donor.

Methods

We evaluated the effect of donor parity on transplant outcomes in a large homogeneously treated population that received an HLA-matched allo-HSCT between 2010 and 2021 at our center. All patients were transplanted from a peripheral blood stem cell source following a myeloablative Busulfan-based conditioning and an identical protocol for graftversus-host disease (GVHD) prophylaxis regimen.

Results

A total of 1103 allo-HSCT recipients were included. 188 (17%) had transplants from parous female donors, whereas 621 (56.30%) and 294 (26.70%) received transplants from male and nulliparous female donors, respectively. HSCTs from parous female donors compared to male and nulliparous females were associated with a significantly higher incidence of grade III-IV acute (a) GVHD (55.27% vs. 11.34 and 10.84%) and extensive chronic (c) GVHD (64.32% vs. 15.52 and 13.65%), as well as lower relapse incidence (RI).

Discussion

This study finds that while parous female donors are associated with higher incidences of grade III-IV aGVHD and extensive cGVHD post-allo-HSCT, the advantages, such as a lower RI, outweigh the risks. The results of our study provide valuable insights for donor selection.

Chronic graft-versus-host disease. Part I: Epidemiology, pathogenesis, and clinical manifestations

Chronic graft-versus-host disease is a major complication of allogeneic hematopoietic cell transplantation and a leading cause of long-term morbidity, nonrelapse mortality, and impaired health-related quality of life. The skin is commonly affected and presents heterogeneously, making the role of dermatologists critical in both diagnosis and treatment. In addition, new clinical classification and grading schemes inform treatment algorithms, which now include 3 U.S. Food and Drug Administration-approved therapies, and evolving transplant techniques are changing disease epidemiology. Part I reviews the epidemiology, pathogenesis, clinical manifestations, and diagnosis of chronic graft-versus-host disease. Part II discusses disease grading and therapeutic management.

Unrelated female-to-male bone marrow transplantation would be preferred over cord blood transplantation in male patients

BACKGROUND AIMS

Allogeneic hematopoietic stem cell transplantation from female donors to male recipients (female-to-male allo-HCT) is a well-established risk factor for a greater incidence of non-relapse mortality (NRM) and chronic graft-versus-host disease (GVHD). In contrast, unrelated cord blood transplantation (UCBT) is associated with a lower incidence of chronic GVHD. In this study, survival outcomes were compared between the UCBT and unrelated female-to-male bone marrow transplantation (UFMBMT) groups.

METHODS

We evaluated male allo-HCT recipients who underwent UCBT or UFMBMT between 2012 and 2020 in Japan. There were 2517 cases in the UCBT group, 456 cases in the HLA-matched UFMBMT group and 457 cases in the HLA-mismatched UFMBMT group.

RESULTS

HLA-mismatched UFMBMT was significantly associated with a decreased risk of relapse (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.57-0.98], P = 0.033) and HLA-matched UFMBMT had the tendency of a decreased risk of relapse (HR 0.78; 95% CI 0.61-1.01, P = 0.059). HLA-matched UFMBMT was also associated with favorable OS (HR 0.82; 95% CI 0.69-0.97, P = 0.021). The relationship between the donor sources and relapse was similarly observed in the lymphoid malignancy cohort.

CONCLUSIONS

The difference of graft-versus leukemia effect by H-Y immunity according to donor sources might contribute to the difference in clinical impact. It might be desirable for patients who could sufficiently wait for donor coordination to select BMT rather than UCBT, even if only unrelated female donors are available for male recipients.

Impact of anti-thymocyte globulin on survival outcomes in female-to-male allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic cell transplantation between female donors and male recipients (female-to-male allo-HCT) is a well-established risk factor for inferior survival outcomes due to a higher incidence of graft-versus-host disease (GVHD). However, a clinical significance of anti-thymocyte globulin (ATG) in the female-to-male allo-HCT has not been elucidated. In this study, we retrospectively evaluated male patients who underwent allo-HCT between 2012 and 2019 in Japan. In the female-to-male allo-HCT cohort (n = 828), the use of ATG was not associated with a decreased risk of GVHD (HR of acute GVHD 0.691 [95% CI: 0.461-1.04], P = 0.074; HR of chronic GVHD 1.06 [95% CI: 0.738-1.52], P = 0.76), but was associated with favorable overall survival (OS) and a decreased risk of non-relapse mortality (NRM) (HR of OS 0.603 [95% CI: 0.400-0.909], P = 0.016; HR of NRM 0.506 [95% CI: 0.300-0.856], P = 0.011). The use of ATG in female-to-male allo-HCT resulted in survival outcomes that were almost equivalent to those in the male-to-male allo-HCT group. Therefore, GVHD prophylaxis with ATG might overcome the inferiority of survival outcomes in female-to-male allo-HCT.

Age and allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia

Although several studies have reported significant effects of patient age on outcomes of allogeneic hematopoietic cell transplantation (HCT), the prognostic relevance of age must be determined separately for myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC). We analyzed Japanese nationwide transplantation registry data of patients aged 20-79 years with acute myeloid leukemia who underwent allogeneic HCT using MAC (n = 7525) or RIC (n = 3154) between 2008 and 2019. Patient were divided into six groups by age, with each group representing a decade, and overall survival (OS), relapse, and non-relapse mortality (NRM) were compared between adjacent age groups. The adverse impact of age on OS increased each decade starting at age 40 among patients receiving MAC, but only differed significantly between patients in their 50s and 60s among those receiving RIC. In patients receiving both MAC and RIC, the detrimental effect of advanced age on OS was accompanied by an increased risk of NRM. These findings show that age affects NRM and OS significantly, but differs depending on conditioning intensity. RIC mitigates the adverse prognostic impact of older age and is thus considered a reasonable option for older patients.

Vitiligo-like manifestations of graft-versus-host disease in a pediatric population

Vitiligo-like changes are an uncommon cutaneous manifestation of graft-versus-host disease (GVHD). We report three cases and review the literature of pediatric patients with vitiligo-like changes associated with GVHD. Improved characterization of this phenomenon may lend insight into the biologic pathways that underlie both vitiligo and GVHD.

Incomplete chimerism following myeloablative and anti-thymocyte globulin-conditioned hematopoietic cell transplantation is a risk factor for relapse and chronic graft-versus-host disease

BACKGROUND AIMS

The value of routine chimerism determination after myeloablative hematopoietic cell transplantation (HCT) is unclear, particularly in the setting of anti-thymocyte globulin (ATG)-based graft-versus-host disease (GVHD) prophylaxis.

METHODS

Blood samples were collected at 3 months post-HCT from 558 patients who received myeloablative conditioning and ATG-based GVHD prophylaxis. Chimerism was assessed using multiplex polymerase chain reaction of short tandem repeats in sorted T cells (CD3+) and leukemia lineage cells (CD13+CD33+ for myeloid malignancies and CD19+ for B-lymphoid malignancies). ATG exposure was determined using a flow cytometry-based assay. The primary outcomes of interest were relapse and chronic GVHD (cGVHD).

RESULTS

Incomplete (<95%) T-cell chimerism and leukemia lineage chimerism were present in 17% and 4% of patients, respectively. Patients with incomplete T-cell chimerism had a significantly greater incidence of relapse (36% versus 22%, subhazard ratio [SHR] = 2.03, P = 0.001) and lower incidence of cGVHD (8% versus 25%, SHR = 0.29, P < 0.001) compared with patients with complete chimerism. In multivariate modeling, patients with high post-transplant ATG area under the curve and any cytomegalovirus (CMV) serostatus other than donor/recipient seropositivity (non-D+R+) had an increased likelihood of incomplete T-cell chimerism. Patients with incomplete leukemia lineage chimerism had a significantly greater incidence of relapse (50% versus 23%, SHR = 2.70, P = 0.011) and, surprisingly, a greater incidence of cGVHD (45% versus 20%, SHR = 2.64, P = 0.003).

CONCLUSIONS

High post-transplant ATG exposure and non-D+R+ CMV serostatus predispose patients to incomplete T-cell chimerism, which is associated with an increased risk of relapse. The increased risk of cGVHD with incomplete B-cell/myeloid chimerism is a novel finding that suggests an important role for recipient antigen-presenting cells in cGVHD pathogenesis.

Natural Barcodes for Longitudinal Single Cell Tracking of Leukemic and Immune Cell Dynamics

Blood malignancies provide unique opportunities for longitudinal tracking of disease evolution following therapeutic bottlenecks and for the monitoring of changes in anti-tumor immunity. The expanding development of multi-modal single-cell sequencing technologies affords newer platforms to elucidate the mechanisms underlying these processes at unprecedented resolution. Furthermore, the identification of molecular events that can serve as in-vivo barcodes now facilitate the tracking of the trajectories of malignant and of immune cell populations over time within primary human samples, as these permit unambiguous identification of the clonal lineage of cell populations within heterogeneous phenotypes. Here, we provide an overview of the potential for chromosomal copy number changes, somatic nuclear and mitochondrial DNA mutations, single nucleotide polymorphisms, and T and B cell receptor sequences to serve as personal natural barcodes and review technical implementations in single-cell analysis workflows. Applications of these methodologies include the study of acquired therapeutic resistance and the dissection of donor- and host cellular interactions in the context of allogeneic hematopoietic stem cell transplantation.

Low-Dose Anti-Thymocyte Globulin Plus Low-Dose Posttransplant Cyclophosphamide as an Effective Regimen for Prophylaxis of Graft Versus Host Disease After Haploidentical Peripheral Blood Stem Cell Transplantation With Maternal/Collateral Related Donors

Maternal and collateral donors were associated with a higher incidence of graft-versus-host disease (GvHD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). A more effective regimen for GvHD prophylaxis after haplo-HSCT with maternal/collateral donors needed to be explored. A retrospective study was performed on 62 patients after haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) with maternal/collateral donors, which included 35 patients with low-dose antithymocyte globulin (ATG) plus low-dose posttransplant cyclophosphamide-based (low-dose ATG/PTCy-based) and 27 with ATG-based regimens for GvHD prophylaxis. The 180-day cumulative incidences (CIs) of grades II-IV and III-IV acute GvHD (aGvHD) were 17.7% and 6.8% in low-dose ATG/PTCy-based group, which were significantly lower than that in ATG-based group (55.4% and 31.9%) (P = 0.003 for grade II-IV and P = 0.007 for III-IV aGvHD). In low-dose ATG/PTCy-based group, the 1-year overall survival (OS) and relapse-free survival (RFS) were 80.0%and 80.4%, which were higher than that in ATG-based group with OS of 59.4% and RFS of 62.0%. In multivariate analysis, the low-dose ATG/PTCy-based regimen significantly reduced the risk of grade II-IV (HR = 0.357; P = 0.049) and grade III-IV aGvHD (HR = 0.190; P = 0.046) as an independent risk factor. The results suggested that the low-dose ATG/PTCy-based regimen could effectively prevent the occurrence of aGvHD after haplo-PBSCT with maternal/collateral donors compared with the ATG-based regimen.

Impact of FLT3 internal tandem duplication and NPM1 mutations in acute myeloid leukemia treated with allogeneic hematopoietic cell transplantation

BACKGROUND AIMS

The internal tandem duplication of FLT3 (FLT3^ITD) and NPM1 mutations (NPM1^mut) are well-established prognostic factors in cytogenetically intermediate-risk acute myeloid leukemia (AML) when treated with chemotherapy alone. However, their prognostic value in the setting of allogeneic hematopoietic cell transplantation (HCT) is controversial.

METHODS

FLT3 and NPM1 mutational status was determined at diagnosis using single-gene polymerase chain reaction or next-generation sequencing in 247 adult patients with cytogenetically intermediate-risk AML who underwent myeloablative HCT. Multivariate Fine-Gray and Cox regression was used to analyze the cumulative incidence of relapse (CIR), relapse-free survival (RFS) and overall survival (OS).

RESULTS

FLT3^ITD and NPM1^mut were present in 74 of 247 (30%) and 79 of 247 (32%) patients, respectively. There was no significant difference between patients without a FLT3^ITD or NPM1^mut (FLT3^NONITD/NPM1^WT) and patients with a FLT3^ITD mutation alone (FLT3^ITD/NPM1^WT) with regard to CIR (P = 0.60), RFS (P = 0.91) or OS (P = 0.66). Similarly, there was no significant difference between FLT3^NONITD/NPM1^WT and FLT3^NONITD/NPM1^mut patients with regard to CIR (P = 0.70), RFS (P = 0.75) or OS (P = 0.95). The presence of a concurrent mutation in NPM1 did not appear to modify the impact of having a FLT3^ITD mutation.

CONCLUSIONS

In contrast to chemotherapy-only treatment, FLT3 and NPM1 mutational status does not appear to predict outcomes in patients with cytogenetically intermediate-risk AML following HCT. These results suggest that HCT may ameliorate the poor prognostic effect of FLT3^ITD mutation and that HCT should be considered over chemotherapy-only treatment in FLT3^ITD-mutated AML.

Female Sex Is Associated with Improved Long-Term Survival Following Allogeneic Hematopoietic Stem Cell Transplantation

Life expectancy for long-term survivors of allogeneic hematopoietic stem cell transplantation (alloHSCT), defined as those living ≥5 years post-transplantation, is significantly lower compared with that of the age-matched general population despite a relatively low primary disease relapse rate at >2 years post-transplantation. Among several factors, patient sex is increasingly recognized as a prognostic indicator of long-term survival. We examined the influence of patient sex and donor-recipient sex matching on overall survival (OS) in a landmark analysis of long-term survivors. Using our institutional database supplemented with individual patient record review, we retrospectively investigated the relative influence of recipient sex and donor-recipient sex matching on outcomes of long-term survivors of alloHSCT between 1994 and 2014. Over this 20-year period, 247 met inclusion criteria for analysis; males and females had similar demographic and treatment characteristics. However, significantly more deaths after the 5-year landmark occurred in male recipients. Interestingly, donor sex did not have a significant impact on OS in multivariate analysis, and differences in OS of donor-recipient sex pairs was driven by recipient sex. In addition to recipient sex, only chronic graft-versus-host disease (cGVHD) retained significance as a covariate with an impact on OS in multivariate analysis. Men experienced slightly higher, but statistically nonsignificant, rates and increased severity of cGVHD, and had higher cGVHD-related mortality compared with females. In this long-term survival analysis of adult alloHSCT recipients, one of the only to include follow-up to 15 years, our results show that women survive significantly longer than men irrespective of their age at transplantation. This outcome is independent of other common pretransplantation prognostic indicators, such as donor sex or performance status at transplantation. The inferior survival in males is consistent with survival outcomes described in the transplantation literature. Increasing evidence suggests a biological basis for long-term sex-determined outcomes, possibly owing to differing rates or severity of cGVHD or sustained alloimmune tolerance in females. Larger studies are warranted to validate these retrospective clinical results.

Prognostic effect of gender on outcome of treatment for adults with acute myeloid leukaemia

There are conflicting reports in the literature suggesting that one gender or the other has a better survival with acute myeloid leukaemia (AML). The present study was done in an attempt to resolve the issue. The effect of gender was examined on 3546 newly diagnosed patients with AML, including 548 patients with acute promyelocytic leukaemia (APL) enrolled in 10 multi-institutional treatment studies from March 1984 to November 2008. Kaplan-Meier estimates were used to estimate event-time distributions for survival and multivariate models were used to examine the gender effect after adjusting for multiple risk factors. P values were based on two-sided tests. Non-APL female patients had a significantly better overall (OS) but not disease-free survival (DFS) than males, irrespective of age, initial white blood cell count, or dose of daunorubicin. No differences were observed for obese or FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-positive patients. Female patients with APL had a significantly better OS and DFS than male patients with APL, and differences in survival were greater for patients with t(15;17) + other cytogenetic abnormalities compared with those with t(15;17) only. Gender is an independent prognostic variable in patients with AML. Whether these survival differences are due to hormonal, genetic or pharmacokinetic differences between the sexes or differential toxin exposure such as smoking is unknown. However, the former seems less likely as patient age did not influence the survival advantage for female patients.

Relationship of donor age and relationship to outcomes of haploidentical transplantation with posttransplant cyclophosphamide

Allogeneic blood or marrow transplantation (BMT) physicians seek to optimize all possible variables to improve outcomes. Selectable factors include conditioning, graft-versus-host disease (GVHD) prophylaxis, graft source, and donor. Many patients, especially those with eligible haploidentical (haplo) donors, will have multiple donor options. We seek to identify factors to optimize the choice of haplo donors when using posttransplantation cyclophosphamide (PTCy) GVHD prophylaxis. We evaluated the effect of modifiable donor characteristics (donor age and relationship) on outcomes following haplo BMT with a uniform nonmyeloablative conditioning and PTCy. From 2002 to 2017, 889 consecutive adult patients underwent nonmyeloablative haplo BMT with PTCy. Median follow-up among survivors was 2.5 years after BMT. Median recipient age was 59 (range: 18 to 76) years and median donor age was 40 (range: 13 to 79) years. Multivariable analyses demonstrated that increasing donor age by decade was associated with poorer overall survival (hazard ratio [HR], 1.13 [1.05, 1.22; P = .0015]), worse progression-free survival (HR, 1.09 [1.02, 1.16; P = .015]), and a higher risk for grade 2 to 4 and grade 3 to 4 GVHD (1.3 [1.06, 1.61; P = .013]), but not for chronic GVHD (HR, 1.06 [0.94, 1.2]; P = .37). These less-favorable results with older donors were attributable to worse nonrelapse mortality (HR, 1.19 [1.05, 1.34]; P = .006), not relapse. Parents were associated with inferior outcomes compared with sibling donors, whereas no significant differences were observed between parental donors. These data suggest that the youngest, adult-sized donors should be preferred when multiple haplo donors are available.

Impact of donor age and kinship on clinical outcomes after T-cell-replete haploidentical transplantation with PT-Cy

Donor selection contributes to improve clinical outcomes of T-cell-replete haploidentical stem cell transplantation (haplo-SCT) with posttransplant cyclophosphamide (PT-Cy). The impact of donor age and other non-HLA donor characteristics remains a matter of debate. We performed a multicenter retrospective analysis on 990 haplo-SCTs with PT-Cy. By multivariable analysis, after adjusting for donor/recipient kinship, increasing donor age and peripheral blood stem cell graft were associated with a higher risk of grade 2 to 4 acute graft-versus-host-disease (aGVHD), whereas 2-year cumulative incidence of moderate-to-severe chronic GVHD was higher for transplants from female donors into male recipients and after myeloablative conditioning. Increasing donor age was associated with a trend for higher nonrelapse mortality (NRM) (hazard ratio [HR], 1.05; P = .057) but with a significant reduced risk of disease relapse (HR, 0.92; P = .001) and improved progression-free survival (PFS) (HR, 0.97; P = .036). Increasing recipient age was a predictor of worse overall survival (OS). Risk of relapse was higher (HR, 1.39; P < .001) in patients aged ≤40 years receiving a transplant from a parent as compared with a sibling. Moreover, OS and PFS were lower when the donor was the mother rather than the father. Pretransplant active disease status was an invariably independent predictor of worse clinical outcomes, while recipient positive cytomegalovirus serostatus and hematopoietic cell transplant comorbidity index >3 were associated with worse OS and PFS. Our results suggest that younger donors may reduce the incidence of aGVHD and NRM, though at higher risk of relapse. A parent donor, particularly the mother, is not recommended in recipients ≤40 years.

Relapsed Chronic Lymphocytic Leukaemia with Concomitant Extensive Chronic Graft versus Host Disease after Allogeneic Haematopoietic Stem Cell Transplantation Successfully Treated with Oral Venetoclax

A middle-aged gentleman who was diagnosed with high-risk chronic lymphocytic leukaemia (CLL), Rai stage IV, Binet C with del(17p) and del(13q) underwent allogeneic haematopoeitic stem cell transplantation (allo-HSCT) from a human leukocyte antigen (HLA) identical sister. The patient developed extensive skin, oral, and liver chronic graft versus host disease (GVHD) required tacrolimus, mycophenolate mofetil (MMF), and prednisolone. At seventh month after allo-HSCT, the patient presented with systemic symptoms, right cervical lymphadenopathy, splenomegaly, marked pancytopaenia, and elevated lactate dehydrogenase (LDH). Bone marrow study, immunophenotyping (IP), chromosome analysis, and PET-CT scan confirmed relapsed CLL with no evidence of Richter's transformation or posttransplant lymphoproliferative disease (PTLD). Withdrawal of immunosuppressant (IS) worsened cutaneous and liver GVHD. Chemotherapy was not a suitable treatment option in view of immunodeficiency. The patient underwent extracorporeal photopheresis (ECP) therapy eventually for extensive chronic GVHD, and the IS were gradually tapered to the minimal effective dose. The relapsed CLL was treated successfully with oral venetoclax accessible via a compassionate drug program. This case highlights challenges in managing relapsed CLL and loss of graft-versus-leukaemia (GVL) effect despite extensive chronic GVHD. Venetoclax is an effective and well-tolerated oral novel agent for relapsed CLL after allo-HSCT.

Allogeneic hematopoietic stem cell transplantation for intermediate-risk acute myeloid leukemia in the first remission: outcomes using haploidentical donors are similar to those using matched siblings

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective and curative treatment for acute myeloid leukemia (AML). We explored the outcome of haploidentical donor (HID) transplantation for intermediate-risk AML and compared to that of matched sibling donor (MSD) transplants. One hundred twenty-seven consecutive patients with intermediate-risk AML in the first complete remission (CR1) who underwent allo-HSCT between January 1, 2015, and August 1, 2016, were enrolled. Thirty-seven patients received MSD grafts, and 90 received HID grafts. The 2-year leukemia-free survival (LFS) of the HID group was comparable to that of the MSD group: 82.0% ± 4.1% versus 82.7% ± 6.4%, P = 0.457. The 2-year cumulative incidences of relapse and transplantation-related mortality (TRM) were comparable between the HID and MSD groups (relapse, 4.5% ± 0.1%, versus 11.5% ± 0.3%, P = 0.550; TRM, 13.4% ± 0.1% vs. 5.8% ± 0.2%, P = 0.154). The HID recipients had a trend of a lower 2-year cumulative incidence of positive posttransplant flow cytometry (FCM+) and relapse than the MSD recipients (5.6% ± 0.1% vs. 19.9% ± 0.5%, P = 0.092). These results suggest that the outcomes of allo-HSCT with HIDs are comparable to those with MSDs in terms of LFS, TRM, and relapse for intermediate-risk AML in CR1. HIDs could be an alternative to MSDs for intermediate-risk AML.

New Approaches for the Treatment of Chronic Graft-Versus-Host Disease: Current Status and Future Directions

Chronic graft-versus-host disease (cGvHD) is a severe complication of allogeneic hematopoietic stem cell transplantation that affects various organs leading to a reduced quality of life. The condition often requires enduring immunosuppressive therapy, which can also lead to the development of severe side effects. Several approaches including small molecule inhibitors, antibodies, cytokines, and cellular therapies are now being developed for the treatment of cGvHD, and some of these therapies have been or are currently tested in clinical trials. In this review, we discuss these emerging therapies with particular emphasis on tyrosine kinase inhibitors (TKIs). TKIs are a class of compounds that inhibits tyrosine kinases, thereby preventing the dissemination of growth signals and activation of key cellular proteins that are involved in cell growth and division. Because they have been shown to inhibit key kinases in both B cells and T cells that are involved in the pathophysiology of cGvHD, TKIs present new promising therapeutic approaches. Ibrutinib, a Bruton tyrosine kinase (Btk) inhibitor, has recently been approved by the Food and Drug Administration (FDA) in the United States for the treatment of adult patients with cGvHD after failure of first-line of systemic therapy. Also, Janus Associated Kinases (JAK1 and JAK2) inhibitors, such as itacitinib (JAK1) and ruxolitinib (JAK1 and 2), are promising in the treatment of cGvHD. Herein, we present the current status and future directions of the use of these new drugs with particular spotlight on their targeting of specific intracellular signal transduction cascades important for cGvHD, in order to shed some light on their possible mode of actions.

Global Metabolomics in Allogeneic Hematopoietic Cell Transplantation Recipients Discordant for Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease (cGVHD) remains a significant late effect issue for allogeneic hematopoietic cell transplantation (allo-HCT) survivors, contributing to morbidity and mortality. The etiology of cGVHD is not well elucidated. Owing to a lack of early diagnostic tests and pathophysiology ambiguity, targeted treatments remain limited. Biomarkers for prediction, control response, or prognostication have not yet been identified. Metabolomics, the quantification of metabolites, is a potential biomarker of cGVHD but has not been evaluated in this population. In this study, we examined global metabolites of stored plasma to identify differentially expressed metabolites of individuals discordant for cGVHD following allo-HCT. A descriptive, comparative, cross-sectional study design was used to examine differentially expressed metabolites of plasma samples obtained from 40 adult allo-HCT recipients (20 with cGVHD and 20 without cGVHD) from 2 parent studies. Metabolomics profiling was conducted at the University of Florida's Southeast Center for Integrative Metabolomics. Full experimental methods followed a previously published method. All statistical analyses were performed by a PhD-prepared, trained bioinformatics statistician. There were 10 differentially expressed metabolites between participants with cGVHD and those without cGVHD. Differential metabolites included those related to energy metabolism (n = 3), amino acid metabolism (n = 3), lipid metabolism (n = 2), caffeine metabolism (n = 1), and neurotransmission (n = 1). Serotonin had the greatest fold change (21.01). This study suggests that cGVHD may be associated with expanded cellular energy and potentially mitochondrial dysfunction. The differential metabolic profile between patients with and without cGVHD indicates metabolic perturbations that merit further exploration as potential biomarkers of cGVHD. These findings support the need for further examination using a larger, prospective study design to identify metabolomic risk factors that may signal the need for earlier preventive measures and earlier treatment to reduce cGVHD.

BM is preferred over PBSCs in transplantation from an HLA-matched related female donor to a male recipient

The use of granulocyte colony-stimulating factor-mobilized peripheral blood stem cells (PBSCs) and sex-mismatched hematopoietic cell transplantation (HCT), especially with female donors and male recipients (FtoM), is known to be associated with an increased risk of chronic graft-versus-host disease (GVHD) compared with transplantation with bone marrow (BM). This raises the question of whether the use of PBSCs in FtoM HCT might affect allogeneic responses, resulting in fatal complications. Using a Japanese transplantation registry database, we analyzed 1132 patients (FtoM, n = 315; MtoF, n = 260; sex-matched, n = 557) with standard-risk diseases who underwent HCT with an HLA-matched related donor without in vivo T-cell depletion between 2013 and 2016. The impact of PBSC vs BM on transplantation outcomes was separately assessed in FtoM, MtoF, and sex-matched HCT. Overall survival (OS) and nonrelapse mortality (NRM) at 2 years post-HCT were significantly worse in patients with PBSCs vs those with BM in FtoM HCT (2-year OS, 76% vs 62%; P = .0084; 2-year NRM, 10% vs 21%; P = .0078); no differences were observed for MtoF or sex-matched HCT. Multivariate analyses confirmed the adverse impact of PBSCs in FtoM HCT (hazard ratio [HR] for OS, 1.91; P = .025; HR for NRM, 3.70; P = .0065). In FtoM HCT, patients with PBSCs frequently experienced fatal GVHD and organ failure. In conclusion, the use of PBSCs in FtoM HCT was associated with an increased risk of NRM in the early phase, resulting in inferior survival. This suggests that, when we use female-related donors for male patients in HCT, BM may result in better outcomes than PBSCs.

Impact of donor and recipient characteristics on graft-versus-host disease and survival in HLA-matched sibling hematopoietic stem cell transplantation

OBJECTIVE

To analyze the impact of donor- and recipient-related factors on Graft-versus-host disease (GVHD) and overall survival of transplantation from matched sibling donors.

METHOD

we retrospectively analyzed the clinical features of 68 consecutive hematological patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) from matched sibling from 2011 and 2017.

RESULTS

The incidence of Ⅱ- Ⅳacute GVHD (aGVHD) and chronic GVHD (cGVHD) after transplantation was 13.6 % and 19.7 %, respectively. We also noted the donor and recipient characteristics had no impact on Ⅱ- Ⅳ aGVHD incidence.We found sex mismatch (F-M) did not increase the risk of cGVHD in the model if a female donor was younger than 30 years (P = 1.000), but cGVHD increased if the female donor was ≥30 years (P = 0.002). Recipients≥40 years undergoing HCT from donors ≥30 years were at higher risk for cGVHD (P = 0.021). Development of Ⅱ- Ⅳ aGVHD and cGVHD had no effect on overall survival (P = 0.159, 0.081). Non-remission status at allo-HCT was linked to lower overall survival (P = 0.001).

CONCLUSION

The incidence of cGVHD was higher when male recipients received hematopoietic progenitor cells from female ≥30 years donors, and when older than 40 years recipients received hematopoietic progenitor cells from ≥30 years donors. Patients in non-remission status at allo-HCT was inclined to have lower overall survival.

T-Cell Immunotherapies Targeting Histocompatibility and Tumor Antigens in Hematological Malignancies

Over the last decades, T-cell immunotherapy has revealed itself as a powerful, and often curative, strategy to treat blood cancers. In hematopoietic cell transplantation, most of the so-called graft-vs.-leukemia (GVL) effect hinges on the recognition of histocompatibility antigens that reflect immunologically relevant genetic variants between donors and recipients. Whether other variants acquired during the neoplastic transformation, or the aberrant expression of gene products can yield antigenic targets of similar relevance as the minor histocompatibility antigens is actively being pursued. Modern genomics and proteomics have enabled the high throughput identification of candidate antigens for immunotherapy in both autologous and allogeneic settings. As such, these major histocompatibility complex-associated tumor-specific (TSA) and tumor-associated antigens (TAA) can allow for the targeting of multiple blood neoplasms, which is a limitation for other immunotherapeutic approaches, such as chimeric antigen receptor (CAR)-modified T cells. We review the current strategies taken to translate these discoveries into T-cell therapies and propose how these could be introduced in clinical practice. Specifically, we discuss the criteria that are used to select the antigens with the greatest therapeutic value and we review the various T-cell manufacturing approaches in place to either expand antigen-specific T cells from the native repertoire or genetically engineer T cells with minor histocompatibility antigen or TSA/TAA-specific recombinant T-cell receptors. Finally, we elaborate on the current and future incorporation of these therapeutic T-cell products into the treatment of hematological malignancies.

Outcome of donor and recipient sex match versus mismatch in stem cell transplant procedure

Aim

We determined the frequency of graft-versus-host disease (GvHD) and overall survival (OS) in sex matched vs mismatched transplant.

Methods

Medical records were analyzed of patients undergoing transplant from 2004 to 2016. Variables included age, sex of patient and donor, indication, conditioning regimen, stem cell source, frequency of GvHD and OS.

Results

We performed n = 162 allogeneic stem cell transplants. The most common conditioning regimen was busulfan/cyclophosphamide (n = 64). There was no difference in the frequency of GvHD in both groups. The transplant related mortality was higher (8.7%) in sex-mismatched transplants. The OS in both groups was similar.

Conclusion

Our study showed higher transplant-related mortality in sex-mismatched transplant. There was no difference in GvHD and OS in both groups.

The Graft-Versus-Leukemia Effect in AML

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the most established and commonly used cellular immunotherapy in cancer care. It is the most potent anti-leukemic therapy in patients with acute myeloid leukemia (AML) and is routinely used with curative intent in patients with intermediate and poor risk disease. Donor T cells, and possibly other immune cells, eliminate residual leukemia cells after prior (radio)chemotherapy. This immune-mediated response is known as graft-versus-leukemia (GvL). Donor alloimmune responses can also be directed against healthy tissues, which is known as graft-versus-host disease (GvHD). GvHD and GvL often co-occur and, therefore, a major barrier to exploiting the full immunotherapeutic benefit of donor immune cells against patient leukemia is the immunosuppression required to treat GvHD. However, curative responses to allo-SCT and GvHD do not always occur together, suggesting that these two immune responses could be de-coupled in some patients. To make further progress in successfully promoting GvL without GvHD, we must transform our limited understanding of the cellular and molecular basis of GvL and GvHD. Specifically, in most patients we do not understand the antigenic basis of immune responses in GvL and GvHD. Identification of antigens important for GvL but not GvHD, and vice versa, could impact on donor selection, allow us to track GvL immune responses and begin to specifically harness and strengthen anti-leukemic immune responses against patient AML cells, whilst minimizing the toxicity of GvHD.

Fludarabine/busulfan versus fludarabine/total-body-irradiation (2 Gy) as conditioning prior to allogeneic stem cell transplantation in patients (≥60 years) with acute myelogenous leukemia: a study of the acute leukemia working party of the EBMT

Nonmyeloablative (NMA) conditioning regimens facilitate allogeneic stem cell transplantation (alloSCT) in elderly patients and/or in those with comorbidities. The acute leukemia working party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT) compared the outcomes of patients ≥60 years with AML in first complete remission (CR1), that had received an alloSCT following NMA conditioning, i.e. either fludarabine/busulfan (FB2) or fludarabine/total-body-irradiation-2Gy (FluTBI2Gy). A total of 1088 patients were included (median age 65 years). Donors were matched siblings (MSD) and matched unrelated donors (MUD) in 47% and 53%, respectively. In vivo T-cell depletion (TCD) was applied to 79% and none (0%) of patients in the FB2 and FluTBI2Gy groups, respectively. In the MSD group we found a trend for less extensive cGVHD in patients receiving FB2 with in vivo TCD, HR: 0.49, p = 0.08, and in those without worse NRM, HR: 2.14, p = 0.04, and a trend for more total cGVHD, HR: 1.61, p = 0.09. Patients transplanted from MUDs had a significantly higher incidence of total cGVHD, extensive cGVHD and a worse GRFS with FluTBI2Gy in comparison to FB2, HR: 2.44; p < 0.0001; HR 4.59; p < 0.00001 and HR: 1.35; p = 0.03, respectively. No differences were observed with respect to LFS, OS, RI, NRM, and aGVHD.

Who is the best haploidentical donor for acquired severe aplastic anemia? Experience from a multicenter study

BACKGROUND

Haploidentical transplantation has been proposed as an effective treatment for severe aplastic anemia (SAA). The majority of patients have more than one HLA-haploidentical donor. Herein, we compared the outcomes between different donor-recipient relationships for optimal haploidentical donor selection in acquired SAA.

METHODS

We conducted a multicenter study based on a registered database of 392 patients with SAA treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT) between 2006 and 2018. In total, 223 patients received grafts from father donors, 47 from mother donors, 91 from siblings, 29 from children, and 2 from collateral donors.

RESULTS

Of the 381 patients who survived more than 28 days, 379 (99.5%) recipients were engrafted. The 2-year overall survival (OS) was 86.6 ± 2.5%, 87.1 ± 4.9%, 84.3 ± 3.9%, and 92.2 ± 5.1% for recipients of father, mother, sibling, and child grafts, respectively, (P = 0.706). The 2-year failure-free survival (FFS) was 82.8 ± 2.7%, 86.7 ± 5.1%, 80.8 ± 4.2%, and 92.5 ± 5.1% for recipients of father, mother, sibling, and child grafts, respectively, (P = 0.508). There was no difference in the incidence of either acute or chronic graft-versus-host disease (GVHD) among the different donor sources in multivariate analyses. There were also no differences in the OS or FFS among the different donor sources in the Cox regression analysis. However, OS was significantly better in the patients with a shorter history of aplastic anemia (< 12 months), better performance status (ECOG scores 0-1), or moderate graft mononuclear cell (MNC) counts (6-10 × 10⁸/kg), and in female recipients with male donors. The FFS was also higher in patients with a shorter history of aplastic anemia (< 12 months) and better performance status (ECOG scores 0-1).

CONCLUSIONS

Fathers, mothers, siblings, and children are all suitable haploidentical donors for patients with SAA.

Graft-versus-host disease in recipients of male unrelated donor compared with parous female sibling donor transplants

Optimal donor selection is critical for successful allogeneic hematopoietic cell transplantation (HCT). Donor sex and parity are well-established risk factors for graft-versus-host disease (GVHD), with male donors typically associated with lower rates of GVHD. Well-matched unrelated donors (URDs) have also been associated with increased risks of GVHD as compared with matched sibling donors. These observations raise the question of whether male URDs would lead to more (or less) favorable transplant outcomes as compared with parous female sibling donors. We used the Center for International Blood and Marrow Transplant Research registry to complete a retrospective cohort study in adults with acute myeloid leukemia, acute lymphoblastic leukemia, or myelodysplastic syndrome, who underwent T-cell replete HCT from these 2 donor types (parous female sibling or male URD) between 2000 and 2012. Primary outcomes included grade 2 to 4 acute GVHD (aGVHD), chronic GVHD (cGVHD), and overall survival. Secondary outcomes included disease-free survival, transplant-related mortality, and relapse. In 2813 recipients, patients receiving male URD transplants (n = 1921) had 1.6 times higher risk of grade 2 to 4 aGVHD (P < .0001). For cGVHD, recipient sex was a significant factor, so donor/recipient pairs were evaluated. Female recipients of male URD grafts had a higher risk of cGVHD than those receiving parous female sibling grafts (relative risk [RR] = 1.43, P < .0001), whereas male recipients had similar rates of cGVHD regardless of donor type (RR = 1.09, P = .23). Donor type did not significantly affect any other end point. We conclude that when available, parous female siblings are preferred over male URDs.

Comparable Outcomes after Hematopoietic Stem Cell Transplantation from Mother Donors and Matched Unrelated Donors in Patients with Hematopoietic Malignancies

Haploidentical transplantations have achieved comparable survival as HLA fully matched unrelated donors (URDs). When choosing the best donor for HLA haploidentical transplantations, most institutions prioritize using young male donors over mother donors. In a retrospective study we compared outcomes in mother donor and URD transplantations. We found that both 2-year overall survival and 2-year leukemia-free survival were comparable between the mother donor group and URD group (74.8% versus 72.9%, P = .937, and 71.7% versus 67.0%, P = .580, respectively). Higher incidences of grades II to IV acute graft-versus-host disease (GVHD) and chronic GVHD were observed in the mother donor group than in the URD group (43.5% versus 14.0%, P = .001, and 62.2% versus 38.7%, P = .007, respectively). The 2-year cumulative incidences of relapse were significantly decreased in the mother donor group (7.6% versus 20.9%, P = .036). These findings suggest mother donor transplantations could achieve comparable survival with URD transplantations and exhibited decreased rates of relapse but increased rates of GVHD, indicating that mother donors would be a suitable choice for patients without an identical sibling donor.

The role of collateral related donors in haploidentical hematopoietic stem cell transplantation

A key issue in the haploiedntical hematopoietic stem cell transplantation (haplo-HSCT) setting is the search for the best donor, because donor selection can significantly impact the clinical outcomes. We aimed to identify the role of collateral related donors (CRDs) in donor selection for haplo-HSCT through comparing the clinical outcomes between CRDs (n = 60) and maternal donors (MDs, n = 296), which were the last choice of donor selection in immediate related donors (IRDs). The cumulative incidence of graft-versus-host disease was comparable between CRDs and MDs. The 5-year cumulative incidence of relapse and non-relapse mortality was 22.0% (95% CI, 11.3%-32.7%) versus 17.4% (95% CI, 13.0%-21.8%) (P = 0.455) and 25.0% (95% CI, 13.9%-36.1%) versus 23.1% (95% CI, 18.2%-28.0%) (P = 0.721) for the CRDs and MDs, respectively. The 5-year probabilities of disease-free survival and overall survival was 53.2% (95% CI, 40.4%-66.0%) versus 59.5% (95% CI, 53.8%-65.2%) (P = 0.406) and 56.5% (95% CI, 43.8%-69.2%) versus 61.8% (95% CI, 56.1%-67.5%) (P = 0.458) for the CRDs and MDs, respectively. Female donor/male recipient (FDMR) CRDs were associated with the poorest clinical outcomes, and the clinical outcomes of non-FDMR CRDs were comparable to those of MDs. In summary, our results showed that CRDs did not showed superiority over MDs. Thus, IRDs should be the first choice of donor selection, and CRDs could only be the donors for those without IRDs.

[Influence of donor-recipient sex matching on outcomes of haploidentical hematopoietic stem cell transplantation for acute leukemia]

Objective: To determine the influence of donor-recipient sex matching on outcome of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for acute leukemia in the setting of T-cell-replete transplants. Methods: The retrospective study is based on 1 160 consecutive patients who received their first haplo-HSCT for acute leukemia between April 2002 and December 2014 at Peking University Institute of Hematology. The patients were divided into the sex-matched group and sex-mismatched group in terms of the recipient and donor sex. Then we conducted an analysis in four subgroups, male patients with male donors (M→M), male patients with female donors (F→M), female patients with female donors (F→F), and female patients with male donors (M→F). Transplant outcomes were measured in terms of hematopoietic recovery, acute graft versus host disease (aGVHD), relapse, nonrelapse mortality (NRM), disease-free survival (DFS) and overall survival (OS) in the above four subgroups. Then univariate and multivariate analysis were conducted. Results: There was a higher 3-year and 5-year NRM but no difference in other transplant outcomes in sex-mismatched group when compared with the sex-matched group. F→M was compared with M→M, and the former group had higher 3-year and 5-year cumulative incidences of NRM (25.5% vs 16.1%, P=0.002; 27.1% vs 17.3%, P=0.002), decreased 5-year DFS (56.9% vs 64.4%, P=0.044), decreased 3-year OS (62.6% vs 69.8%, P=0.045). There was no significant difference in 3-year DFS and 5-year OS. There was no significant difference in grade Ⅱ-Ⅳ aGVHD and cGVHD incidence. When F→F group was compared with M→F group, only a higher grade Ⅱ-Ⅳ aGVHD incidence (43.9% vs 34.6%, P=0.047) existed. F→M was proved to be the independent risk factor influencing NRM and OS in multivariate analysis. Conclusion: In haplo-HSCT for acute leukemia, the donor-recipient sex combination of male patients with female donors was of a poorer prognosis, so a male donor was a better choice for a male patient.

Matching donor and recipient based on predicted indirectly recognizable human leucocyte antigen epitopes

The predicted indirectly recognizable human leucocyte antigen (HLA) epitopes (PIRCHE) algorithm is a novel in silico algorithm to determine donor-recipient compatibility. The PIRCHE algorithm determines donor-recipient compatibility by counting the number of mismatched HLA-derived epitopes that are involved in indirect T-cell alloimmune responses; these epitopes are designated as PIRCHE. Over the last few years, the PIRCHE algorithm has been investigated in both hematopoietic stem cell transplantation and solid organ transplantation. This review describes the theory of the algorithm, its application in transplantation, and highlights the future perspectives on the clinical application of the PIRCHE algorithm.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

Background

Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome.

Objective

To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center.

Results

Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality.

Conclusions

In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Young Female Donors Do Not Increase the Risk of Graft-versus-Host Disease or Impact Overall Outcomes in Pediatric HLA-Matched Sibling Hematopoietic Stem Cell Transplantation

Optimal donor selection is critical in hematopoietic stem cell transplantation (HSCT). Donor-recipient sex mismatch, donor age, and female donor-donor parity are known to impact graft-versus-host disease (GVHD) and outcomes in adults. Minor histocompatibility antigens encoded by the human Y chromosome can result in specific antibody formation in some female donors, may increase in frequency with increasing donor age, and may be contributory to the increased incidence of GVHD. To better understand the role of donor age/sex and sex matching in HSCT outcomes, we conducted a retrospective study of pediatric patients receiving their first myeloablative sibling donor HSCT (n = 244) from 1998 to 2012. Observed rates of GVHD were low: 17% of patients surviving past engraftment (n = 243) developed grades II to IV acute GVHD (aGVHD) and 14% surviving ≥ 100 days (n = 229) developed chronic GVHD (cGVHD). On multivariate analysis the risk of aGVHD, cGVHD, and death increased with patient age as expected. Female donor sex and sex mismatch (female donor-male recipient) had no impact on the development of aGVHD. cGVHD was increased with female donors only if the donor was ≥12 years old. No cGVHD was observed among 109 patients aged < 10 years who received a 6/6 HLA-matched marrow HSCT, regardless of donor age or sex. Survival was mostly driven by diagnosis. Results suggest that in pediatric HSCT, young HLA-matched siblings are equivalently good donors regardless of sex or donor-recipient sex mismatch.

Characteristics and risk of chronic graft-versus-host disease of liver in allogeneic hematopoietic stem cell transplant recipients

Chronic graft-versus-host-disease (cGvHD) is a serious complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Among various organ-specific cGvHD, the cGvHD of liver is less well-characterized. In this study, we applied the National Institutes of Health 2014 scoring criteria of cGvHD to analyze a retrospective cohort of 362 allo-HSCT recipients focusing on cGvHD of liver. The overall incidence of liver cGvHD with a score of 3 by 1.5 years post-transplant was 5.8% (21/362). Poor outcome, in terms of overall survival (OS), were observed in patients with scores of 3 liver cGvHD, comparing to those with scores less than 3 (hazard ratio [HR] 2.037, 95% confidence interval [CI] 1.123-3.696, P = 0.019). In multivariate analysis, male gender (HR 4.004, P = 0.042) and chronic hepatitis C virus (HCV) infection status (HR 19.087, P < 0.001) were statistically significant risk factors for scores of 3 liver cGvHD. Our results indicate that liver cGvHD with scores of 3 has a grave prognosis following allo-HSCT, and that HCV carrier status and male are risk factors. Early recognition of this devastating complication might help in prompt immunosuppressive therapy and reducing late poor outcome.

Donor and recipient age, gender and ABO incompatibility regardless of donor source: validated criteria for donor selection for haematopoietic transplants

Prior data indicate similar outcomes after transplants from human leukocyte antigen (HLA)-haplotype-matched relatives, HLA-identical siblings and HLA-matched unrelated donors. We used our prospective data set to answer a clinically important question: who is the best donor for a person with acute leukaemia transplanted in first complete remission. Patients were randomly divided into training (n=611) and validation (n=588) sets. A total of 1199 consecutive subjects received a transplant from an HLA-haplotype-matched relative using granulocyte colony-stimulating factor and anti-thymocyte globulin (n=685) or an HLA-identical sibling (n=514); 3-year leukaemia-free survivals (LFSs) were 75 and 74% (P=0.95), respectively. The multivariate model identified three major risk factors for transplant-related mortality (TRM): older donor/recipient age, female-to-male transplants and donor-recipient ABO major-mismatch transplants. A risk score was developed based on these three features. TRMs were 8%, 15% and 31% for subjects with scores of 0-1, 2 and 3, respectively, (P<0.001). Three-year LFSs were 78%, 74% and 58%, respectively, (P=0.003). The risk score was validated in an independent cohort. In conclusion, our data confirm donor source is not significantly correlated with transplant outcomes. Selection of the best donor needs to consider donor-recipient age, matching for gender and ABO incompatibility among persons with acute leukaemia receiving related transplants under our transplant modality.

Graft-versus-Leukemia Effect Following Hematopoietic Stem Cell Transplantation for Leukemia

The success of hematopoietic stem cell transplantation (HSCT) lies with the ability of the engrafting immune system to remove residual leukemia cells via a graft-versus-leukemia effect (GvL), caused either spontaneously post-HSCT or via donor lymphocyte infusion. GvL effects can also be initiated by allogenic mismatched natural killer cells, antigen-specific T cells, and activated dendritic cells of leukemic origin. The history and further application of this GvL effect and the main mechanisms will be discussed and reviewed in this chapter.

Characteristics predicting outcomes of allogeneic stem-cell transplantation in relapsed acute myelogenous leukemia

BACKGROUND

Allogeneic hematopoietic stem-cell transplantation (ahsct) is associated with significant morbidity and mortality, but it can cure carefully selected patients with acute myeloid leukemia (aml) in second remission (cr2). In a cohort of patients with aml who underwent ahsct in cr2, we determined the pre-transplant factors that predicted for overall survival (os), relapse, and non-relapse mortality. We also sought to validate the prognostic risk groups derived by Michelis and colleagues in this independent population.

METHODS

In a retrospective chart review, we obtained data for 55 consecutive patients who underwent ahsct for aml in cr2. Hazard ratios were used to describe the independent effects of pre-transplant variables on outcome, and Kaplan-Meier curves were used to assess outcomes in the three prognostic groups identified by Michelis and colleagues.

RESULTS

At 1, 3, and 5 years post-transplant, os was 60%, 45.5%, and 37.5% respectively. Statistically significant differences in os, relapse mortality, and non-relapse mortality were not identified between the prognostic risk groups identified by Michelis and colleagues. Women were less likely than men to relapse, and a modified European Society for Blood and Marrow Transplantation (mebmt) score of 3 or less was associated with a lower non-relapse mortality.

CONCLUSIONS

The 37.5% 5-year os in this cohort suggests that, compared with other options, ahsct offers patients with aml in cr2 a better chance of cure. Our study supports the use of the mebmt score to predict non-relapse mortality in this population.

Allogeneic hematopoietic cell transplantation for primary refractory acute lymphoblastic leukemia: A report from the Acute Leukemia Working Party of the EBMT

BACKGROUND

Patients with primary refractory acute lymphoblastic leukemia (PREF ALL) who fail to achieve a complete remission (CR) after ≥2 courses of chemotherapy have a dismal prognosis without undergoing allogeneic hematopoietic cell transplantation (HCT). To the authors' knowledge, there currently are no data regarding factors influencing transplantation outcomes.

METHODS

The authors retrospectively studied outcomes of transplantation for cases of PREF ALL reported to European Society for Blood and Marrow Transplantation registry. Eligibility criteria for the current analysis included adult patients who underwent their first HCT for PREF ALL between 2000 and 2012. PREF disease was defined as the failure to achieve a morphological CR after ≥2 courses of induction chemotherapy.

RESULTS

Data regarding 86 adult patients were analyzed. With a median follow-up of 106 months, the probability of survival was 36% at 2 years and 23% at 5 years. The probability of leukemia-free survival was 28% and 17%, respectively, and the probability of nonrecurrence mortality was 20% and 29%, respectively, at 2 years and 5 years. For 66 patients who achieved a CR (77%), the survival at 2 years and 5 years was 36% and 29%, respectively. In multivariate analysis, use of total body irradiation was found to be associated with improved survival. Total body irradiation and infusion of female hematopoietic cells into male recipients was associated with improved leukemia-free survival. These findings were incorporated into a scoring system that identified 3 groups (those with 2, 1, or no prognostic factors) with survival rates of 57%, 22%, and 8%, respectively.

CONCLUSIONS

Although overall these patients would clearly benefit from the introduction of novel antileukemic therapies, the data from the current study support the use of allogeneic HCT in selected patients with PREF ALL. Cancer 2017;123:1965-1970. © 2017 American Cancer Society.

Risk factors for treatment failure after allogeneic transplantation of patients with CLL: a report from the European Society for Blood and Marrow Transplantation

For young patients with high-risk CLL, BTK-/PI3K-inhibitors or allogeneic stem cell transplantation (alloHCT) are considered. Patients with a low risk of non-relapse mortality (NRM) but a high risk of failure of targeted therapy may benefit most from alloHCT. We performed Cox regression analyses to identify risk factors for 2-year NRM and 5-year event-free survival (using EFS as a surrogate for long-term disease control) in a large, updated EBMT registry cohort (n= 694). For the whole cohort, 2-year NRM was 28% and 5-year EFS 37%. Higher age, lower performance status, unrelated donor type and unfavorable sex-mismatch had a significant adverse impact on 2-year NRM. Two-year NRM was calculated for good- and poor-risk reference patients. Predicted 2-year-NRM was 11 and 12% for male and female good-risk patients compared with 42 and 33% for male and female poor-risk patients. For 5-year EFS, age, performance status, prior autologous HCT, remission status and sex-mismatch had a significant impact, whereas del(17p) did not. The model-based prediction of 5-year EFS was 55% and 64%, respectively, for male and female good-risk patients. Good-risk transplant candidates with high-risk CLL and limited prognosis either on or after failure of targeted therapy should still be considered for alloHCT.