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Background: Acute graft-versus-host disease (aGvHD) is a major cause of death for patients following allogeneic hematopoietic stem cell transplantation (HSCT). Effective management of moderate to severe aGvHD remains challenging despite recent advances in HSCT, emphasizing the importance of prophylaxis and risk factor identification., Methods: In this study, we analyzed data from 1479 adults who underwent HSCT between 2005 and 2017 to investigate the effects of aGvHD prophylaxis and time-dependent risk factors on the development of grades II-IV aGvHD within 100 days post-HSCT., Results: Using a dynamic longitudinal time-to-event model, we observed a non-monotonic baseline hazard overtime with a low hazard during the first few days and a maximum hazard at day 17, described by Bateman function with a mean transit time of approximately 11 days. Multivariable analysis revealed significant time-dependent effects of white blood cell counts and cyclosporine A exposure as well as static effects of female donors for male recipients, patients with matched related donors, conditioning regimen consisting of fludarabine plus total body irradiation, and patient age in recipients of grafts from related donors on the risk to develop grades II-IV aGvHD. Additionally, we found that higher cumulative hazard on day 7 after allo-HSCT are associated with an increased incidence of grades II-IV aGvHD within 100 days indicating that an individual assessment of the cumulative hazard on day 7 could potentially serve as valuable predictor for later grades II-IV aGvHD development. Using the final model, stochastic simulations were performed to explore covariate effects on the cumulative incidence over time and to estimate risk ratios., Conclusion: Overall, the presented model showed good descriptive and predictive performance and provides valuable insights into the interplay of multiple static and time-dependent risk factors for the prediction of aGvHD., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Despite advances in allogeneic hematopoietic cell transplantation, acute graft-versus-host disease (aGVHD) remains its leading complication, yet with heterogeneous outcomes. Here, we analyzed aGVHD phenotypes and clinical classifications in depth in large, multicenter cohorts involving 3019 patients and addressed prevailing gaps by developing data-driven models. We compared, tested and verified these along with all conventional classifications in independent cohorts and found that data-driven grading outperformed conventional grading in Akaike information criterion and concordance index metrics. Data-driven classifications refined aGVHD assessment with up to 12 severity grades, which were associated with distinct nonrelapse mortality (NRM) and confirmed the key role of intestinal aGVHD. We developed an online calculator for physicians to implement principal component-derived grading (PC1). These results provide substantial insight into the evaluation of aGVHD phenotypes and multiorgan involvement, which relegates the exclusive reporting of overall aGVHD severity grades in transplant registries and clinical trials. Data-driven aGVHD grading provides an expandable platform to refine classification and transplant risk assessment., (© 2023. The Author(s).)

Intravenously infused treosulfan was evaluated in adult and pediatric patients for conditioning regimen prior to allogeneic hematopoietic stem cell transplantation. A population pharmacokinetic (PK) model was initially developed on 116 adult and pediatric PK profiles from historical trials, to support treosulfan dose recommendations for children in 2 prospective trials. The aim was to assess and update the initial population PK model by inclusion of additional 83 pediatric PK profiles from these 2 trials. The final population PK model was 2-compartmental with dosing in the central compartment, linear elimination, and inter-compartmental clearance. Inter-individual variability was included on clearance (CL), central volume (V1), peripheral volume (V2), and inter-compartmental clearance (Q). The final model described an effect of the body surface area (BSA) on CL, V1, V2, and Q. The final model resulted in a modified dose recommendation for children and advises treosulfan doses of 10 g/m 2 , 12 g/m 2 , and 14 g/m 2 for BSAs of <0.4 m 2 , ≥0.4 to <0.9 m 2 , and ≥0.9 m 2 , respectively. This simplified BSA-dependent dose recommendation was developed for children, ensuring a well comparable treosulfan exposure as a dose of 14 g/m 2 in adults - irrespective of their age and without applying individual therapeutic drug monitoring., Competing Interests: Declaration of competing interest XL, JK, AKM, and JB are employees of medac GmbH. All other authors declare no conflict of interest., (Copyright © 2023 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.)

Introduction: Anti-T-lymphocyte globulin (ATG) or post-transplant cyclophosphamide (PTCy) prevent graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT), yet individual patients benefit differentially., Methods: Given the sparse comparative data on the impact of cellular immune reconstitution in this setting, we studied flow cytometry and clinical outcomes in 339 recipients of 10/10 matched-unrelated donor (MUD) HCT using either ATG (n=304) or PTCy (n=35) for in vivo T cell manipulation along with a haploidentical PTCy control cohort (n=45). Longitudinal cellular immune reconstitution data were analyzed conventionally and with a data science approach using clustering with dynamic time warping to determine the similarity between time-series of T cell subsets., Results: Consistent with published studies, no significant differences in clinical outcomes were observed at the cohort level between MUD-ATG and MUD-PTCy. However, cellular reconstitution revealed preferences for distinct T cell subpopulations associating with GVHD protection in each setting. Starting early after HCT, MUD-PTCy patients had higher regulatory T cell levels after HCT (p <0.0001), while MUD-ATG patients presented with higher levels of γδ T- or NKT cells (both p <0.0001). Time-series clustering further dissected the patient population's heterogeneity revealing distinct immune reconstitution clusters. Importantly, it identified phenotypes that reproducibly associated with impaired clinical outcomes within the same in vivo T cell manipulation platform. Exemplarily, patients with lower activated- and αβ T cell counts had significantly higher NRM (p=0.032) and relapse rates (p =0.01)., Discussion: The improved understanding of the heterogeneity of cellular reconstitution in MUD patients with T cell manipulation both at the cohort and individual level may support clinicians in managing HCT complications., Competing Interests: ATT: Consultancy for CSL Behring and Maat Pharma. DB received travel subsidies from Medac, all outside the submitted work. HCR received consulting and lecture fees from Abbvie, AstraZeneca, Vertex, Novartis, and Merck. HCR received research funding from Gilead Pharmaceuticals and AstraZeneca. HCR is a co-founder and shareholder of CDL Therapeutics GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Leserer, Graf, Franke, Bogdanov, Arrieta-Bolaños, Buttkereit, Leimkühler, Fleischhauer, Reinhardt, Beelen and Turki.)

Allogeneic hematopoietic stem cell transplantation (HCT) is standard treatment for adult high-risk (HR) acute lymphoblastic leukemia (ALL) and contributed to the overall improved outcome. We report a consecutive cohort of prospectively defined HR patients treated on German Multicenter Acute Lymphoblastic Leukemia trials 06/99-07/03 with similar induction/consolidation therapy and HCT in first remission. A total of 542 patients (15-55 years) with BCR-ABL-negative ALL were analyzed. Sixty-seven percent received HCT from matched unrelated donors (MUD) and 32% from matched sibling donors (MSD). The incidence of non-relapse mortality (NRM) was 20% at 5 years. NRM occurred after median 6.6 months; the leading cause (46%) was infection. NRM after MUD decreased from 39% in trial 06/99 to 16% in trial 07/03 (P < .00001). Patient age was the strongest predictor of NRM. The 5-year relapse incidence was 23% using MSD and 25% using MUD. Minimal residual disease (MRD) was the strongest predictor of relapse (45% for molecular failure versus 6% for molecular CR; P < .0001). The median follow-up was 67 months, and the 5-year survival rate was 58%. Age, subtype/high risk feature, MRD status, trial and acute GvHD were significant prognostic factors. We provide a large reference analysis with long follow-up confirming a similar outcome of MSD and MUD HCT and improved NRM for MUD HCT over years. MRD has a strong impact on relapse risk, whereas age was the strongest predictor of NRM. New adapted conditioning strategies should be considered for older patients combined with the goal to reduce the MRD level before stem cell transplantation., Competing Interests: Declaration of Competing Interest M.B. received personal fees from Incyte (advisory board) and Roche Pharma AG, financial support for reference diagnostics from Affimed and Regeneron, grants and personal fees from Amgen (advisory board, speakers bureau, travel support), and personal fees from Janssen (speakers bureau). G.K. received research funding from Celgene and Amgen, Lecture fees, advisory board fees and travel support from Celgene, Amgen, Pfizer, Jazz, Neovii, Takeda, Medac, Biotest, Eurocept, MSD, Roche, Iqone, Novartis, Gilead and Abbvie N.A received honoraria for lectures from Amgen; honoraria for advisory board from Gilead, MSD Sharp & Dohme GmbH, Pfizer, Amgen, Travel grant from Gilead, MSD Sharp & Dohme GmbH, Pfizer and Amgen. N.G. received speaker honoraria, travel support or advisory board fees from Amgen, Celgene, Gilead, Novartis, Pfizer, Jazz Pharmaceuticals, Incyte, Cellestia, Erytech and Morphosys and research support (institution) from Amgen, Pfizer, Novartis, Shire/Servier, Jazz Pharmaceuticals and Incyte., (Copyright © 2022 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Allogeneic hematopoietic cell transplantation (HCT) effectively treats high-risk hematologic diseases but can entail HCT-specific complications, which may be minimized by appropriate patient management, supported by accurate, individual risk estimation. However, almost all HCT risk scores are limited to a single risk assessment before HCT without incorporation of additional data. We developed machine learning models that integrate both baseline patient data and time-dependent laboratory measurements to individually predict mortality and cytomegalovirus (CMV) reactivation after HCT at multiple time points per patient. These gradient boosting machine models provide well-calibrated, time-dependent risk predictions and achieved areas under the receiver-operating characteristic of 0.92 and 0.83 and areas under the precision-recall curve of 0.58 and 0.62 for prediction of mortality and CMV reactivation, respectively, in a 21-day time window. Both models were successfully validated in a prospective, non-interventional study and performed on par with expert hematologists in a pilot comparison., (© 2022 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

To determine the survival benefit of allogeneic hematopoietic cell transplantation (allo-HCT) in chronic myelomonocytic leukemias (CMML), we assembled a retrospective cohort of CMML patients 18-70 years old diagnosed between 2000 and 2014 from an international CMML dataset (n = 730) and the EBMT registry (n = 384). The prognostic impact of allo-HCT was analyzed through univariable and multivariable time-dependent models and with a multistate model, accounting for age, sex, CMML prognostic scoring system (low or intermediate-1 grouped as lower-risk, intermediate-2 or high as higher-risk) at diagnosis, and AML transformation. In univariable analysis, lower-risk CMMLs had a 5-year overall survival (OS) of 20% with allo-HCT vs 42% without allo-HCT (P < .001). In higher-risk patients, 5-year OS was 27% with allo-HCT vs 15% without allo-HCT (P = .13). With multistate models, performing allo-HCT before AML transformation reduced OS in patients with lower-risk CMML, and a survival benefit was predicted for men with higher-risk CMML. In a multivariable analysis of lower-risk patients, performing allo-HCT before transformation to AML significantly increased the risk of death within 2 years of transplantation (hazard ratio [HR], 3.19; P < .001), with no significant change in long-term survival beyond this time point (HR, 0.98; P = .92). In higher-risk patients, allo-HCT significantly increased the risk of death in the first 2 years after transplant (HR 1.46; P = .01) but not beyond (HR, 0.60; P = .09). Performing allo-HCT before AML transformation decreases life expectancy in lower-risk patients but may be considered in higher-risk patients., (© 2022 by The American Society of Hematology.)

The phase III study was designed to compare event-free survival (EFS) after treosulfan-based conditioning with a widely applied reduced-intensity conditioning (RIC) busulfan regimen in older or comorbid patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic cell transplantation (HCT). A previously reported confirmatory interim analysis of the randomized clinical study including 476 patients demonstrated statistically significant noninferiority for treosulfan with clinically meaningful improvement in EFS. Here, the final study results and pre-specified subgroup analyses of all 570 randomized patients with completed longer-term follow-up are presented. Patients presenting HCT-specific comorbidity index >2 or aged ≥50 years were randomly assigned (1:1) to intravenous (IV) fludarabine with either treosulfan (30 g/m 2 IV) or busulfan (6.4 mg/kg IV) after stratification by disease risk group, donor type, and participating institution. The primary endpoint was EFS with disease recurrence, graft failure, or death from any cause as events. EFS of patients (median age 60 years) was superior after treosulfan compared to RIC busulfan: 36-months-EFS rate 59.5% (95% CI, 52.2-66.1) vs. 49.7% (95% CI, 43.3-55.7) with a hazard ratio (HR) of 0.64 (95% CI, 0.49-0.84), p = 0.0006. Likewise, overall survival (OS) with treosulfan was superior compared to busulfan: 36-month-OS rate 66.8% vs. 56.3%; HR 0.64 (95% CI, 0.48-0.87), p = 0.0037. Post hoc analyses revealed that these differences were consistent with the confirmatory interim analysis, and thereby the treosulfan regimen appears particularly suitable for older AML and MDS patients., (© 2022 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Weight loss and metabolic activity influence outcome after allogeneic stem cell transplantation (alloSCT). This study evaluates pre-conditioning Leptin, a peptide hormone involved in metabolism and immune homeostasis, as a prognostic factor for survival, relapse and non-relapse mortality (NRM) following alloSCT. Leptin serum levels prior to conditioning were determined in a cohort of patients transplanted for various hematologic malignancies ( n = 524) and correlated retrospectively with clinical outcome. Findings related to patients with acute leukemia (AL) from this sample were validated in an independent cohort. Low pre-conditioning serum Leptin was an independent prognostic marker for increased risk of relapse (but not of NRM and overall mortality) following alloSCT for AL of intermediate and advanced stage (beyond first complete remission). Multivariate analysis revealed a hazard ratio (HR) for relapse of 0.75 per log2 increase (0.59-0.96, p = 0.020). This effect was similar in an independent validation cohort. Pre-conditioning serum Leptin was validated as a prognostic marker for early relapse by fitting the multivariate Cox model to the validation data. Pre-conditioning serum Leptin levels may serve as an independent prognostic marker for relapse following alloSCT in intermediate and advanced stage AL patients. Prospective studies are required to prove whether serum Leptin could be used for guiding nutritional intervention in patients with AL undergoing alloSCT.

The incidence and severity of viral complications after cellular therapy are highly variable. Recent publications describe relevant interactions between the human Cytomegalovirus (CMV) and host immunity in recipients of allogeneic hematopoietic cell transplantation (HCT). Although immune monitoring is routinely performed in HCT patients, validated cut-off levels correlating with transplant outcomes such as survival or CMV reactivation are mostly limited to day +100, which is later than the median time for CMV reactivation in the absence of medical prophylaxis. To address this gap in early risk assessment, we applied an unsupervised machine learning technique based on clustering of day +30 CD4 + helper T cell count data, and identified relevant cut-off levels within the diverse spectrum of early CD4 + reconstitution. These clusters were stratified for CMV recipient serostatus to identify early risk groups that predict clinical HCT outcome. Indeed, the new risk groups predicted subsequent clinical events such as NRM, OS, and high CMV peak titers better than the most established predictor, i.e., the positive CMV recipient serostatus (R+). More specifically, patients from the R+/low CD4 + subgroup strongly associated with high CMV peak titers and increased 3-year NRM (subdistribution hazard ratio (SHR) 10.1, 95% CI 1.38-73.8, p = 0.023), while patients from the R-/very high CD4 + subgroup showed comparable NRM risks (SHR 9.57, 95% CI 1.12-81.9, p = 0.039) without such an association. In short, our study established novel cut-off levels for early CD4 + T cells via unsupervised learning and supports the integration of host cellular immunity into clinical risk-assessment after HCT in the context of CMV reactivation.

Programmed cell death protein-1 (PD-1) is an inhibitory co-receptor required for regulating immune responsiveness and maintaining immune homeostasis. As PD-1 can be released as bioactive soluble molecule, we investigated the clinical significance of soluble PD-1 (sPD-1) after allogeneic hematopoietic stem cell transplantation (HSCT) regarding graft-versus-host disease (GvHD), relapse, and overall survival (OS) in a mono-centric cohort of 82 patients. Compared to pre-HSCT and to healthy controls, post-HSCT sPD-1 plasma levels were significantly increased during an observation time of three months. Univariate analysis revealed that low sPD-1 plasma levels at month one, two or three post HSCT were associated with acute GvHD grade III-IV, the onset of moderate/severe chronic GvHD (cGvHD) and inferior OS, DFS, and TRM, respectively. No relationship was detected to relapse rates. sPD-1 plasma levels were significantly increased in ATG-treated patients compared to ATG-untreated patients. Multivariate analysis revealed that a low sPD-1 plasma levels status at one or two month(s) after HSCT is an independent indicator for inferior OS, DFS, or TRM. A low sPD-1 plasma levels status at month three post HSCT is predictive for the onset of moderate/severe cGvHD. Thus, our study pinpoints the soluble inhibitory co-receptor PD-1 as a promising candidate molecule for the prediction of clinical HSCT outcome., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kordelas, Buttkereit, Heinemann, Horn, Giebel, Beelen, Reinhardt and Rebmann.)

Even in the era of PCR-based monitoring, prophylaxis, and preemptive therapy, Cytomegalovirus (CMV) viremia remains a relevant cause of non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT). However, studies using binary analysis (presence/absence of CMV) reported contradicting data for NRM, overall survival and leukemia relapse. Here, we analyzed CMV replication kinetics in 11 508 whole blood PCR samples of 705 patients with HCT between 2012 and 2017. Using two independent models based on CMV peak titers and on the time point of first CMV reactivation, we stratified patients into risk cohorts. Each cohort had distinct cellular immune reconstitution profiles and differentiated for relevant clinical outcomes. Patients with high CMV peak titers had significantly reduced overall survival (HR 2.13, 95% CI 1.53-2.96; p < .0001), due to high NRM. Early impaired T cell reconstitution was a risk factor for high CMV peak titers, however relevant CMV viremia also related to boosted T cell reconstitution. Importantly, intermediate CMV peak titers associated with a significantly reduced relapse probability (HR 0.53, 95% CI 0.31-0.91; p = .022). In short, CMV kinetics models distinguished relevant clinical outcome cohorts beyond the R+ serostatus with distinct immune reconstitution patterns and resolve in part contradicting results of previous studies exclusively focused on the presence or absence of CMV., (© 2021 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

The inclusion of mutation status improved risk stratification for newly diagnosed patients with chronic myelomonocytic leukemia (CMML). Stem cell transplantation is a potentially curative treatment option, and patient selection is critical because of relevant transplant-related morbidity and mortality. We aimed to evaluate the impact of mutation status together with clinical presentations on posttransplant outcome. Our study included 240 patients with a median follow-up of 5.5 years. A significant association with worse survival was identified for the presence of mutations in ASXL1 and/or NRAS. In multivariable analysis, ASXL1- and/or NRAS-mutated genotype (hazard ratio [HR], 1.63), marrow blasts >2% (HR, 1.70), and increasing comorbidity index (continuous HR, 1.16) were independently associated with worse survival. A prognostic score (CMML transplant score) was developed, and the following points were assigned: 4 points for an ASXL1- and/or NRAS-mutated genotype or blasts >2% and 1 point each for an increase of 1 in the comorbidity index. The CMML transplant score (range, 0-20) was predictive of survival and nonrelapse mortality (P < .001 for both). Up to 5 risk groups were identified, showing 5-year survival of 81% for a score of 0 to 1, 49% for a score of 2 to 4, 43% for a score of 5 to 7, 31% for a score of 8 to 10, and 19% for a score >10. The score retained performance after validation (concordance index, 0.68) and good accuracy after calibration. Predictions were superior compared with existing scores designed for the nontransplant setting, which resulted in significant risk reclassification. This CMML transplant score, which incorporated mutation and clinical information, was prognostic in patients specifically undergoing transplantation and may facilitate personalized counseling., (© 2021 by The American Society of Hematology.)

The optimal conditioning for patients with acute myeloid leukemia in first complete remission treated with allogeneic hematopoietic cell transplantation (allo-HCT) has not been defined so far. In this retrospective study, we compared two "reduced-toxicity" regimens: intravenous busulfan at a total dose of 9.6 mg/kg (3 days) + fludarabine (Bu3/Flu) and total body irradiation at a dose of 8 Gy + fludarabine (TBI8Gy/Flu). In the entire study cohort (n = 518), the probabilities of overall survival (OS), leukemia-free survival (LFS), relapse and non-relapse mortality (NRM) at 2 years for Bu3/Flu and TBI8Gy/Flu were 62% vs. 72.5% (p = 0.051), 59.5% vs. 65% (p = 0.15), 30% vs. 20% (p = 0.01), and 10% vs. 14% (p = 0.18), respectively. In multivariate model for patients <50 years old, TBI8Gy/Flu was associated with improved LFS (hazard ratio (HR) = 0.5, p = 0.04), OS (HR = 0.31, p = 0.004), and survival free from both graft-versus-host disease and relapse (HR = 0.55, p = 0.03), as well as tendency to reduced risk of relapse (HR = 0.53, p = 0.08). Among patients aged 50 years or older the use of TBI8Gy/Flu was associated with increased incidence of NRM (HR = 3.9, p = 0.0009), with no significant impact on other outcome measures. We conclude that the use of TBI8Gy/Flu as "reduced-toxicity" regimen may be advised in younger patients with AML referred for allo-HCT.

The Acute Leukemia Working Party (ALWP) of the EBMT assessed the outcome of allogeneic stem cell transplantation (alloSCT) in patients with relapsed/refractory AML (r/rAML) evaluating six sequential conditioning regimens (SR) groups. A total of 2132 patients were included. LFS at 2 years was 28.9%, 33.6%, 35.3%, 20.6%, 24.4%, and 27% for the FLAMSA-TBI4, FLAMSA-Chemo, Mel-Flu-TBI8, Mel-Treo-Flu, Thio-ETO-Cy-Bu2-Flu, and Clo-ARAC-(Bu2/TBI4)-Cy groups, respectively. In patients <55 years of age Mel-Flu-TBI8 had the best LFS, which was statistically significant only in comparison to the Mel-Treo-Flu group, while in patients ≥55 years LFS was best with FLAMSA-Chemo without significant differences compared to FLAMSA-TBI4 and Mel-Flu-TBI8. Furthermore, best NRM rates were obtained with the two FLAMSA regimens groups. Our study suggests that in younger (<55 years) patients a more intense regimen might be used whereas in older (≥55 years) patients the focus might be more on tolerability.

Karyotypic analysis at time of diagnosis has an important value in determining initial response to treatment, remission duration and overall survival (OS) in acute myeloid leukemia (AML). Less is known about its value before allogeneic hematopoietic cell transplantation (allo-HCT) in patients transplanted with active disease, either relapsed or primary refractory (Rel-Ref) AML. We explored the impact of cytogenetic risk (stratification according to MRC-UK) in 2089 patients with either Ref (n = 972) or Rel AML (n = 1117) transplanted during the period 2000-2017. Overall, 154 patients had a favorable risk, 1283 had an intermediate risk and 652 had an adverse cytogenetic risk. Median follow-up was 49 months. Compared to the favorable risk group, intermediate and adverse risk patients were associated with worse leukemia-free survival and OS and also with a higher incidence of relapse. In a subgroup analysis of patients in the intermediate risk group harboring Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD), this remained an important prognostic factor, being associated with worse outcomes. When analyzing patients according to the intensity of the conditioning regimen, no differences were observed for the main transplant outcomes. In conclusion, in patients diagnosed with AML and transplanted with active disease, karyotype remains an important prognostic factor, allowing splitting patients into different risk groups according to their cytogenetics. Similarly, FLT3-ITD mutation also remains a negative prognostic factor in this population., (© 2020 Wiley Periodicals LLC.)

The critical question in the management of chronic myelomonocytic leukemia (CMML) is which patients may benefit from allogeneic hematopoietic cell transplantation (allo-HCT). Using ad hoc statistical analysis, we designed a multicenter retrospective study to determine outcomes in 261 patients age ≤70 years at diagnosis who underwent allo-HCT (n = 119) compared with those who did not (n = 142) according to the current CMML-specific prognostic scoring system (CPSS). Categorizing patients as lower risk (CPSS low/intermediate-1) or higher risk (intermediate-2/high) showed significantly improved outcomes after transplantation in higher-risk patients, with a 37% reduced hazard for death. However, although higher CPSS was associated with worse outcomes in the nontransplantation group, the score was of limited utility for post-transplantation risk stratification. This study may provide further support for the potentially beneficial role of allo-HCT in terms of long-term survival in higher-risk patients but also underscores the need for transplantation-specific risk assessment. Recognizing limitations of retrospective comparisons, larger and prospective comparisons are needed to further refine the indication for allo-HCT and thus counseling of patients with CMML., (Copyright © 2020 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Evidence on volume outcome associations for autologous stem cell transplantation (ASCT) in multiple myeloma (MM) is limited. We investigated ASCT utilization patterns and volume outcome associations in the German National Registry for Stem Cell Transplants (DRST). MM patients with an upfront ASCT between 1998 and 2014 registered in the DRST were included. ASCT utilization increased strongly from 6% to 17% between 1999 and 2013 with the largest increase for patients aged 60-64 years (8-34%). The mean number of ASCTs conducted in the hospitals per year varied (quintiles, Q1:0.0-8.2 to Q5:31.0-102.7). Center volume was not associated with survival after upfront ASCT (lowest vs. highest center volume, hazard ratios and 95% confidence intervals: 0.95 (0.76-1.18), p  = 0.92). Our findings may reflect a high standard of care and degree of specialization of centers performing ASCT for MM in Germany.

Testosterone is an important determinant of endothelial function and vascular health in men. As both factors play a role in mortality after allogeneic stem cell transplantation (alloSCT), we retrospectively evaluated the impact of pre-transplant testosterone levels on outcome in male patients undergoing alloSCT. In the discovery cohort (n=346), an impact on outcome was observed only in the subgroup of patients allografted for acute myeloid leukemia (AML) (n=176, hereafter termed 'training cohort'). In the training cohort, lower pre-transplant testosterone levels were significantly associated with shorter overall survival (OS) [hazard ratio (HR) for a decrease of 100 ng/dL: 1.11, P =0.045]. This was based on a higher hazard of non-relapse mortality (NRM) (cause-specific HR: 1.25, P =0.013), but not relapse (cause-specific HR: 1.06, P =0.277) in the multivariable models. These findings were replicated in a confirmation cohort of 168 male patients allografted for AML in a different center (OS, HR: 1.15, P =0.012 and NRM, cause-specific HR: 1.23; P =0.008). Next, an optimized cut-off point for pre-transplant testosterone was derived from the training set and evaluated in the confirmation cohort. In multivariable models, low pre-transplant testosterone status (<250 ng/dL) was associated with worse OS (hazard ratio 1.95, P =0.021) and increased NRM (cause-specific HR 2.68, P =0.011) but not with relapse (cause-specific HR: 1.28, P =0.551). Our findings may provide a rationale for prospective studies on testosterone/androgen assessment and supplementation in male patients undergoing alloSCT for AML., (Copyright© 2020 Ferrata Storti Foundation.)

Several studies suggest that harnessing natural killer (NK) cell reactivity mediated through killer cell immunoglobulin-like receptors (KIRs) could reduce the risk of relapse after allogeneic hematopoietic cell transplantation. Based on one promising model, information on KIR2DS1 and KIR3DL1 and their cognate ligands can be used to classify donors as KIR-advantageous or KIR-disadvantageous. This study was aimed at externally validating this model in unrelated donor hematopoietic cell transplantation. The impact of the predictor on overall survival (OS) and relapse incidence was tested in a Cox regression model adjusted for patient age, a modified disease risk index, Karnofsky performance status, donor age, HLA match, sex match, cytomegalovirus match, conditioning intensity, type of T-cell depletion, and graft type. Data from 2222 patients with acute myeloid leukemia or myelodysplastic syndrome were analyzed. KIR genes were typed by using high-resolution amplicon-based next-generation sequencing. In univariable analyses and subgroup analyses, OS and the cumulative incidence of relapse of patients with a KIR-advantageous donor were comparable to patients with a KIR-disadvantageous donor. The adjusted hazard ratio from the multivariable Cox regression model was 0.99 (Wald test, P = .93) for OS and 1.04 (Wald test, P = .78) for relapse incidence. We also tested the impact of activating donor KIR2DS1 and inhibition by KIR3DL1 separately but found no significant impact on OS and the risk of relapse. Thus, our study shows that the proposed model does not universally predict NK-mediated disease control. Deeper knowledge of NK-mediated alloreactivity is necessary to predict its contribution to graft-versus-leukemia reactions and to eventually use KIR genotype information for donor selection., (© 2020 by The American Society of Hematology.)

Prophylaxis of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HCT) remains challenging. Because prospective randomized trials of in-vivo T cell depletion using anti-T-lymphocyte globulin (ATLG) in addition to a calcineurin inhibitor and methotrexate (MTX) led to conflicting outcome results, we evaluated the impact of ATLG on clinical outcome, lymphocyte- and immune reconstitution survival models. In total, 1500 consecutive patients with hematologic malignancies received matched unrelated donor (MUD) HCT with cyclosporin and MTX (N = 723, 48%) or with additional ATLG (N = 777, 52%). In the ATLG cohort, grades III-IV acute (12% vs 23%) and extensive chronic GVHD (18% vs 34%) incidences were significantly reduced (P < .0001). Nonrelapse mortality (27% vs 45%) and relapse (30% vs 22%) differed also significantly. Event-free and overall survival estimates at 10 years were 44% and 51% with ATLG and 33% and 35% without ATLG (P < .002 and <.0001). A dose-dependent ATLG effect on lymphocyte- and neutrophil reconstitution was observed. At ATLG exposure, lymphocyte counts and survival associated through a logarithmically increasing function. In this survival model, the lymphocyte count optimum range at exposure was between 0.4 and 1.45/nL (P = .001). This study supports additional ATLG immune prophylaxis and is the first study to associate optimal lymphocyte counts with survival after MUD-HCT., (© 2019 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of The American Society of Transplantation and the American Society of Transplant Surgeons.)

The success of allogeneic hematopoietic stem cell transplantation (alloSCT) is indicated by the reconstitution of the peripheral blood system of patients after alloSCT and the engraftment of hematopoietic stem and progenitor cells (HSPCs) into their bone marrow (BM). The number of CD34 + cells is commonly used as surrogate for the content of hematopoietic stem cells in the grafts. During the last decade, several antigens (including CD133, CD45RA, CD38, and CD10) were identified allowing discrimination of different HSPC subpopulations within the human CD34 + cell compartment. Although such studies increased our understanding of early human hematopoiesis tremendously, hardly any study dissected the CD34 + compartment in the alloSCT setting. Consequently, we comprehensively analyzed the CD34 + compartment in G-CSF-stimulated peripheral blood stem cell grafts of allogeneic donors, in BM samples of the respective recipients 4 weeks after alloSCT, and in BM samples of healthy donors. We demonstrate that alloSCT is associated with a dramatic shift from primitive to more mature HSPC types. Upon investigating whether the composition of engrafted CD34 + cells has any impact on the incidence and severity of graft-versus-host disease, we did not find any correlation. However, more detailed analyses of the CD34 + compartment may elucidate associations with other transplantation-related complications.

Background: Assessment of measurable residual disease (MRD) is rapidly transforming the therapeutic and prognostic landscape of a wide range of hematological malignancies. Its prognostic value in acute lymphoblastic leukemia (ALL) has been established and MRD measured at the end of induction is increasingly used to guide further therapy. Although MRD detectable immediately before allogeneic hematopoietic cell transplantation (HCT) is known to be associated with poor outcomes, it is unclear if or to what extent this differs with different types of conditioning., Methods: In this retrospective registry study, we explored whether measurable residual disease (MRD) before allogeneic hematopoietic cell transplantation (HCT) for acute lymphoblastic leukemia is associated with different outcomes in recipients of myeloablative total body irradiation (TBI)-based versus chemotherapy-based conditioning. We analyzed outcomes of 2780 patients (median age 38 years, range 18-72) who underwent first HCT in complete remission between 2000 and 2017 using sibling or unrelated donors., Results: In 1816 of patients, no disease was detectable, and in 964 patients, MRD was positive. Conditioning was TBI-based in 2122 (76%) transplants. In the whole cohort MRD positivity was a significant independent factor for lower overall survival (OS) and leukemia-free survival (LFS), and for higher relapse incidence (RI), with respective hazard ratios (HR, 95% confidence intervals) of 1.19 (1.02-1.39), 1.26 (1.1-1.44), and 1.51 (1.26-1.8). TBI was associated with a higher OS, LFS, and lower RI with HR of 0.75 (0.62-0.90), 0.70 (0.60-0.82), and 0.60 (0.49-0.74), respectively. No significant interaction was found between MRD status and conditioning. When investigating the impact of MRD separately in the TBI and chemotherapy-based conditioning cohorts by multivariate analysis, we found MRD positivity to be associated with lower OS and LFS and higher RI in the TBI group, and with higher RI in the chemotherapy group. TBI-based conditioning was associated with improved outcomes in both MRD-negative and MRD-positive patients., Conclusions: In this large study, we confirmed that patients who are MRD-negative prior to HCT achieve superior outcomes. This is particularly apparent if TBI conditioning is used. All patients with ALL irrespective of MRD status benefit from TBI-based conditioning in the myeloablative setting.

Transplantation of hematopoietic cells from a healthy individual (allogeneic hematopoietic cell transplantation (allo-HCT)) demonstrates that adoptive immunotherapy can cure blood cancers: still, post-transplantation relapses remain frequent. To explain their drivers, we analyzed the genomic and gene expression profiles of acute myeloid leukemia (AML) blasts purified from patients at serial time-points during their disease history. We identified a transcriptional signature specific for post-transplantation relapses and highly enriched in immune-related processes, including T cell costimulation and antigen presentation. In two independent patient cohorts we confirmed the deregulation of multiple costimulatory ligands on AML blasts at post-transplantation relapse (PD-L1, B7-H3, CD80, PVRL2), mirrored by concomitant changes in circulating donor T cells. Likewise, we documented the frequent loss of surface expression of HLA-DR, -DQ and -DP on leukemia cells, due to downregulation of the HLA class II regulator CIITA. We show that loss of HLA class II expression and upregulation of inhibitory checkpoint molecules represent alternative modalities to abolish AML recognition from donor-derived T cells, and can be counteracted by interferon-γ or checkpoint blockade, respectively. Our results demonstrate that the deregulation of pathways involved in T cell-mediated allorecognition is a distinctive feature and driver of AML relapses after allo-HCT, which can be rapidly translated into personalized therapies.

The curative potential of allogeneic hematopoietic cell transplantation (allo-HCT) in the treatment of acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) relies mainly on the graft-versus-leukemia effect. Relapse after allo-HCT occurs in a considerable proportion of patients and has a dismal prognosis, with still very limited curative potential. This review provides an overview of the established and evolving approaches to preventing or treating relapse of AML and MDS after allo-HCT, in the context of novel insight into the biology of relapse. Established prophylactic measures to prevent relapse include optimized conditioning and graft-versus-host disease (GVHD) prophylaxis, as well as donor lymphocyte infusion (DLI) for high-risk patients; novel immunomodulatory interventions and maintenance approaches are still experimental. Improved diagnostics can detect persistent or recurring disease at a molecular level, enabling early preemptive interventions. Established options include hypomethylating agents and DLI. Standard treatments for hematologic relapse include chemotherapy, cessation of immunosuppressive treatment, and DLI. Experimental approaches include molecular targeted therapies, novel immunomodulatory treatments, and second allo-HCT. For all interventions, the potential risks, including occurrence of GVHD, must be weighed against the benefits individually in each patient. Concurrently, prevention and treatment of relapse after allo-HCT remain challenging and unmet medical needs., (Copyright © 2019 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Despite significant advances in the treatment of complications requiring intensive care unit (ICU) admission, ICU mortality remains high for patients after allogeneic stem cell transplantation. We evaluated the role of thrombocytopenia and poor graft function in allogeneic stem cell recipients receiving ICU treatments along with established prognostic ICU markers in order to identify patients at risk for severe complications. At ICU admission, clinical and laboratory data of 108 allogeneic stem cell transplanted ICU patients were collected and retrospectively analyzed. Platelet counts (≤ 50,000/μl, p < 0.0005), hemoglobin levels (≤ 8.5 mg/dl, p = 0.019), and leukocyte count (≤ 1500/μl, p = 0.025) along with sepsis (p = 0.002) and acute myeloid leukemia (p < 0.0005) correlated significantly with survival. Multivariate analysis confirmed thrombocytopenia (hazard ratio (HR) 2.79 (1.58-4.92, 95% confidence interval (CI)) and anemia (HR 1.82, 1.06-3.11, 95% CI) as independent mortality risk factors. Predominant ICU diagnoses were acute respiratory failure (75%), acute kidney injury (47%), and septic shock (30%). Acute graft versus host disease was diagnosed in 42% of patients, and 47% required vasopressors. Low platelet (≤ 50,000/μl) and poor graft function are independent prognostic factors for impaired survival in critically ill stem cell transplanted patients. The underlying pathophysiology of poor graft function is not fully understood and currently under investigation. High-risk patients may be identified and ICU treatments stratified according to allogeneic stem cell patients' individual risk profiles. In contrast to previous studies involving medical or surgical ICU patients, the fraction of thrombocytopenic patients was larger and low platelets were a better differentiating factor in multivariate analysis than any other parameter.

Increasing donor-recipient HLA disparity is associated with negative outcomes of allogeneic hematopoietic stem cell transplantation (HSCT), but its comparative relevance amid non-HLA donor characteristics is not well established. We addressed this question in 3215 HSCTs performed between 2005 and 2013 in Germany for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Donors were HLA-matched related (MRD; n = 872) or unrelated (10/10 MUD, n = 1553) or HLA-mismatched unrelated (<10/10 MMUD, n = 790). Overall survival (OS) was similar after MRD compared with 10/10 MUD HSCT, reflecting opposing hazards of relapse (hazard ratio [HR], 1.32; P < .002) and nonrelapse mortality (HR, .63; P < .001). After UD HSCT, increasing HLA disparity was associated with inferior OS (HR, 1.21 [P < .02] and HR, 1.57 [P < .001] for 9/10 and ≤8/10 MMUD, respectively, compared with 10/10 MUD). Among non-HLA donor characteristics, age, sex mismatching (male recipient-female donor), and cytomegalovirus (CMV) mismatching (positive recipient-negative donor) impacted OS. Multivariate subgroup analysis showed that OS was similar after HSCT from the youngest 9/10 MMUD (<30 years) compared with the oldest 10/10 MUD (>40 years) (HR, 1.18; P = .25) and also in male patients transplanted from female 10/10 MUD compared with male 9/10 MMUD (HR, .89; P = .46). In contrast, OS of CMV-positive patients tended to be better with CMV-negative 10/10 MUDs compared with CMV-positive 9/10 MMUDs (HR, 1.31; P = .04). Because of low patient numbers in subgroups, definite conclusions and establishment of a hierarchy among HLA matching and non-HLA donor characteristics could not be made. Our data suggest that the impact of donor age and sex mismatch but not CMV mismatch on outcome of allogeneic HSCT may be comparable with that of single HLA disparity., (Copyright © 2018. Published by Elsevier Inc.)

HLA expression levels have been suggested to be genetically controlled by single nucleotide polymorphisms (SNP) in the untranslated regions (UTR), and expression variants have been associated with the outcome of chronic viral infection and hematopoietic stem cell transplantation (HSCT). In particular, the 3'UTR rs9277534-G/A SNP in HLA-DPB1 has been associated with graft-versus-host-disease after HSCT (Expression model); however its relevance in different immune cells and its mode of action have not been systematically addressed. In addition, there is a strong though not complete overlap between the rs9277534-G/A SNP and structural HLA-DPB1 T cell epitope (TCE) groups which have also been associated with HSCT outcome (TCE Structural model). Here we confirm and extend previous findings of significantly higher HLA-DPB1 expression in B cell lines, unstimulated primary B cells, and monocytes homozygous for rs9277534-G compared to those homozygous for rs9277534-A. However, these differences were abrogated by interferon-γ stimulation or differentiation into dendritic cells. We identify at least seven 3'UTR rs9277534-G/A haplotypes differing by a total of 37 SNP, also characterized by linkage to length variants of a short tandem repeat (STR) in intron 2 and TCE group assignment. 3'UTR mapping did not show any significant differences in post-transcriptional regulation assessed by luciferase assays between two representative rs9277534-G/A haplotypes for any of eight overlapping fragments. Moreover, no evidence for alternative splicing associated with the intron 2 STR was obtained by RT-PCR. In an exemplary cohort of 379 HLA-DPB1 mismatched donor-recipient pairs, risk prediction by the Expression model and the Structural TCE model was 36.7% concordant, with the majority of discordances due to non-applicability of the Expression model. HLA-DPB1 from different TCE groups expressed in the absence of the 3'UTR at similar levels by transfected HeLa cells elicited significantly different mean alloreactive CD4+ T-cell responses, as assessed by CD137 upregulation assays in 178 independent cultures. Taken together, our data provide new insights into the cell type-specific and mechanistic basis of the association between the rs9277534-G/A SNP and HLA-DPB1 expression, and show that, despite partial overlap between both models in HSCT risk-prediction, differential alloreactivity determined by the TCE structural model occurs independently from HLA-DPB1 differential expression.

The success of hematopoietic stem cell transplantation is determined by multiple factors. Additional complexity is conferred by covariables showing time-dependent effects. We evaluated the effect of predictors on competing-risk outcomes after hematopoietic stem cell transplantation in a time-dependent manner. We analyzed 14951 outcomes of adult patients with hematologic malignancies who underwent a first allogeneic transplant. We extended the combined endpoints of disease-free and overall survival to competing-risk settings: disease-free survival was split into relapse and non-relapse mortality. Overall survival was divided into transplant-related mortality, death from other causes and death from unknown causes. For time-dependent effects we computed estimators before and after a covariable-specific cut-point. Patients treated with reduced intensity conditioning had a constantly higher risk of relapse compared to patients treated with myeloablative conditioning. For non-relapse mortality, patients treated with reduced intensity conditioning had a reduced mortality risk but this effect was only seen in the first 4 months after transplantation (hazard ratio: 0.76, P <0.001) and not afterwards. Graft source exhibited a time-dependent effect on both transplant-related mortality (in first year: hazard ratio 0.70, P <0.001; after first year: hazard ratio 1.47, P =0.002) and non-relapse mortality (in first 8 months: hazard ratio 0.75, P <0.001; after first 8 months: hazard ratio 1.38, P <0.001). Patients with a poor Karnofsky performance score (<80) had a considerably higher risk of all endpoints in the first 4 months. The competing-risk analysis for overall survival and disease-free survival allows resolution of effects with different vectors early and later after stem cell transplantation, as shown for graft source. This information may be useful in risk assessment of treatment choices and for counseling patients on an individual basis., (Copyright© 2018 Ferrata Storti Foundation.)

HLA-G is a non-classical class I molecule which induces tolerance in allogeneic situations by inhibition of cytotoxic NK and CD8 + T cells and by induction of regulatory T cells. Concordantly, in solid organ transplantation HLA-G is associated with a lower risk for acute and chronic rejection, whereas its role in allogeneic stem cell transplantation (allo-SCT) is less established. We here present detailed analyses of HLA-G-levels in patients after allo-SCT showing a correlation of elevated soluble HLA-G (sHLA-G) levels with less severe acute (p = 0.06) and chronic GvHD (p = 0.0025) and with a superior overall survival (p = 0.03). Soluble HLA-G levels are also positively correlated with the frequency of regulatory T cells in vivo. These clinical data are corroborated by in vitro analyses showing that patients-derived sHLA-G inhibit allogeneic immune responses. ATG-treatment of patients dominantly affects the sHLA-G levels post allo-SCT. Thus, this study highlights the association of elevated sHLA-G levels with less severe acute and chronic GvHD and provides additional functional analyses elucidating possible tolerance-inducing mechanisms of sHLA-G in the context of allo-SCT.

Allogeneic hematopoietic stem cell transplantation (HSCT) recipients frequently develop acute respiratory failure (ARF) with pulmonary infiltrates. Molecular- and biomarker-based assays enhance pathogen detection, but data on their yield in this population are scarce. This was a retrospective single-center study of 156 consecutive HSCT recipients admitted to the intensive care unit (ICU) between May 2013 and July 2017. Findings from a microbiologic diagnostic workup using currently available methods on bronchoalveolar lavage (BAL) and blood samples from 66 patients (age, 58 years [range, 45 to 64]; HSCT to ICU, 176 days [range, 85 to 407]) with ARF and pulmonary infiltrates were analyzed. In 47 patients (71%) a causative pathogen was identified (fungal, n = 28; viral, n = 26; bacterial, n = 18). Polymicrobial findings involving several pathogen groups occurred in 20 patients (30%). Culture (12/16, 75%), galactomannan (13/15, 87%), and Aspergillus-PCR (8/9, 89%) from BAL but not serum galactomannan (6/14, 43%) helped to diagnose invasive aspergillosis (n = 16, 24%). Aspergillus-PCR detected azole resistance in 2 cases. Mucorales was found in 7 patients (11%; BAL culture, n = 6; Mucorales-PCR, n = 1). Patients with identified pathogens had higher Simplified Acute Physiology Score II scores (P = .049) and inferior ICU survival (6% versus 37%, P < .01), which largely related to the presence of an invasive fungal infection. Eight patients (12%) had 1 or more viruses with uncertain lung pathogenicity as the sole microbiologic finding. A diagnostic microbiologic workup incorporating molecular- and biomarker-based assays identified pathogens in most HSCT recipients with ARF and pulmonary infiltrates admitted to the ICU. Implications of polymicrobial infection and pathogen patterns in these patients warrant further investigation., (Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Allogeneic haematopoietic stem cell transplantation (alloHSCT) is considered a standard treatment for patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL) achieving complete remission after induction containing tyrosine kinase inhibitors (TKIs)., Methods: We retrospectively compared results of myeloablative alloHSCT from either matched sibling donor (MSD) or unrelated donor (URD) with autologous (auto) HSCT for adults with Ph+ ALL in molecular remission, treated between 2007 and 2014., Results: In univariate analysis, the incidence of relapse at 2 years was 47% after autoHSCT, 28% after MSD-HSCT and 19% after URD-HSCT (P = 0.0002). Respective rates of non-relapse mortality were 2%, 18%, and 22% (P = 0.001). The probabilities of leukaemia-free survival were 52%, 55% and 60% (P = 0.69), while overall survival rates were 70%, 70% and 69% (P = 0.58), respectively. In multivariate analysis, there was a trend towards increased risk of overall mortality after MSD-HSCT (hazard ratio [HR], 1.5, P = 0.12) and URD-HSCT (HR, 1.6, P = 0.08) when referred to autoHSCT. The use of total body irradiation (TBI)-based regimens was associated with reduced risk of relapse (HR, 0.65, P = 0.02) and overall mortality (HR, 0.67, P = 0.01)., Conclusion: In the era of TKIs, outcomes of myeloablative autoHSCT and alloHSCT for patients with Ph+ ALL in first molecular remission are comparable. Therefore, autoHSCT appears to be an attractive treatment option potentially allowing for circumvention of alloHSCT sequelae. Irrespective of the type of donor, TBI-based regimens should be considered the preferable type of conditioning for Ph+ ALL., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Considering the unsatisfactory results of salvage therapies for patients with relapsed/refractory acute myeloid leukaemia (R/R-AML), their value before allogeneic haematopoietic stem cell transplantation (HSCT) remains questionable. However, direct allogeneic HSCT following established conditioning regimens applied in patients with R/R-AML during active disease has been equally disappointing. In this retrospective observational study, high-dose melphalan, as part of a sequential preparative regimen, followed by a total body irradiation (4 × 2 Gy)-based or a treosulfan-based dose-adapted conditioning therapy for allogeneic HSCT was administered to 292 adult patients (median age 56 years, range 17-74) with primary refractory (144 patients), secondary refractory (97 patients) or relapsed AML (51 patients). Overall survival rates at 3 years were 34%, 29% and 41%, respectively. Risk factors associated with an inferior survival were higher age, transplantation from a human leucocyte antigen-mismatched donor and high disease burden. Patients transplanted with blast infiltration <20% showed a notable survival rate of 51% at 3 years. In particular, patients with primary refractory AML showed a more favourable outcome when transplanted early during their disease course. Thus, high-dose melphalan-based sequential conditioning chemotherapy followed by an allogeneic HSCT is feasible and enables long-term remission to be achieved in a substantial proportion of patients with active R/R-AML., (© 2018 John Wiley & Sons Ltd.)

Background: CMV reactivation is a major cause of severe complications in allogeneic hematopoietic stem cell transplant (HSCT) recipients. The risk of CMV reactivation depends on the serostatus (+/-) of the donor (D) and recipient (R). The reconstitution of CMV-specific T-cell responses after transplantation is crucial for the control of CMV reactivation., Objectives: The study aimed to determine the cellular immune status correlating with protection from high-level CMV viremia (>5000 copies/ml) and disease., Study Design: We monitored CMV-specific cellular immune responses in 9 high-risk (D-/R+), 14 intermediate risk (D+/R+) and 3 low risk individuals (D+/R-), and 8 CMV negative controls (D-/R-). Interferon- γ (IFN-γ) levels as a marker for the CD8+ T-cell response were determined by the QuantiFERON-CMV-assay and compared to viral loads determined by PCR., Results: Early CMV reactivation was detected in all high-risk and 13/14 intermediate risk individuals. High-level viremia was detected in 5/7 high and 7/14 intermediate risk patients. Reconstitution of the CMV-specific cellular immune response started from 3 months after transplantation and resulted in protection against CMV reactivation. Re-establishing of CMV-specific T-cell immune responses with IFN- γ levels >8.9 IU/ml is crucial for protection from high-level CMV viremia., Conclusions: Monitoring of HSCT-recipients with the QuantiFERON-CMV-assay might be of great benefit to optimize antiviral treatment., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Although quantitative PCR (qPCR) has been explored for chimerism monitoring after allogeneic stem cell transplantation (SCT), evidence regarding its clinical utility compared with standard short tandem repeat (STR) is still limited. We retrospectively studied commercial qPCR and STR chimerism with respective positivity thresholds of .1% and 1% in 359 peripheral blood (PB) and 95 bone marrow (BM) samples from 30 adult patients after first HLA-matched SCT for myeloid malignancies or acute lymphatic leukemia. Concordance between the 2 methods was 79.5%, with all discordant samples positive in qPCR but negative in STR. Of the latter, sporadic qPCR positivity without clinical correlates was seen mostly in BM samples early post-transplant. In 7 of 21 patients with available follow-up samples in the first months after transplantation, qPCR but not STR revealed low levels (<1%) of sustained host chimerism in PB, reflecting delayed engraftment or persistent mixed chimerism (PMC). These conditions were associated with donor-recipient cytomegalovirus (CMV) serostatus and early CMV reactivation but not with immunosuppressive regimens or clinical outcome. qPCR predicted all 8/8 relapses with samples in the 6 months before onset by sustained positivity in both PB and BM compared with 1/8 relapses predicted by STR mainly in BM. The response kinetics to donor lymphocyte infusions for the treatment of PMC or relapse was shown by qPCR but not STR to be protracted over several months in 3 patients. Our results demonstrate the superior clinical utility of qPCR compared with STR for monitoring subtle changes of host chimerism associated with different clinical conditions, making a case for its use in the clinical follow-up of transplant patients., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

A preventive effect of early human cytomegalovirus (HCMV) replication was evaluated in 136 non-Hodgkin lymphoma (NHL) patients with mature B-cell NHLs (n = 94), and mature T- and NK-cell NHLs (n = 42) after allogeneic stem cell transplantation (alloSCT). Most study-patients (85%) had received at least 2 cycles of chemotherapy and 60% had also received an autograft prior to alloSCT. First detection of CMV-replication by HCMV antigenemia/viremia was found at a median of day +33 after alloSCT. The cumulative incidence of relapse at 5 years after alloSCT was 38% (95% confidence interval [95%CI]: 26-49) in 82 patients without compared to 22% (95%CI: 8-37) in 54 patients with HCMV antigenemia/viremia (p = .013). A decreased relapse risk of HCMV replication was confirmed by multivariate analysis for HCMV antigenemia/viremia (Hazard ratio [HR]: 0.29, 95%CI: 0.11-0.76, p < .014). This report demonstrated a possible improvement of relapse incidence after replicative HCMV infection in patients with NHL after alloSCT.

In this retrospective analysis we evaluated the outcome of 313 patients aged ≥ 70 years in the registry of the European Group for Blood and Marrow Transplantation with myelodysplastic syndrome (MDS; n = 221) and secondary acute myeloid leukemia (n = 92) who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from related (n = 79) or unrelated (n = 234) donors. Median age at HSCT was 72 years (range, 70 to 78). Conditioning regimen was nonmyeloablative (n = 54), reduced intensity (n = 207), or standard intensity (n = 52). Allogeneic HSCT for MDS patients ≥ 70 years was increasingly performed over time. Although during 2000 to 2004 only 16 patients received HSCT, during 2011 to 2013 the number of transplantations increased to 181. The cumulative incidence of nonrelapse mortality at 1 year and relapse at 3 years was 32% and 28%, respectively, with a 3-year overall survival rate of 34%. Good performance, determined by Karnofsky performance status, and recipients' seronegativity for cytomegalovirus was associated with 3-year estimated overall survival rates of 43% (P = .01) and 46% (P = .002), respectively. Conditioning intensity did not impact survival. After careful patient selection, allogeneic HSCT can be offered to patients older than 70 years with MDS., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

The role of HLA amino acid (AA) polymorphism for the outcome of hematopoietic cell transplantation (HCT) is controversial, in particular for HLA class II. Here, we investigated this question in nonpermissive HLA-DPB1 T-cell epitope (TCE) mismatches reflected by numerical functional distance (FD) scores, assignable to all HLA-DPB1 alleles based on the combined impact of 12 polymorphic AAs. We calculated the difference in FD scores (ΔFD) of mismatched HLA-DPB1 alleles in patients and their 10/10 HLA-matched unrelated donors of 379 HCTs performed at our center for acute leukemia or myelodysplastic syndrome. Receiver-operator curve-based stratification into 2 ΔFD subgroups showed a significantly higher percentage of nonpermissive TCE mismatches for ΔFD >2.665, compared with ΔFD ≤2.665 (88% vs 25%, P < .0001). In multivariate analysis, ΔFD >2.665 was significantly associated with overall survival (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.05-1.87; P < .021) and event-free survival (HR, 1.39; 95% CI, 1.05-1.82; P < .021), compared with ΔFD ≤2.665. These associations were stronger than those observed for TCE mismatches. There was a marked but not statistically significant increase in the hazards of relapse and nonrelapse mortality in the high ΔFD subgroup, whereas no differences were observed for acute and chronic graft-versus-host disease. Seven nonconservative AA substitutions in peptide-binding positions had a significantly stronger impact on ΔFD compared with 5 others (P = .0025), demonstrating qualitative differences in the relative impact of AA polymorphism in HLA-DPB1. The novel concept of ΔFD sheds new light onto nonpermissive HLA-DPB1 mismatches in unrelated HCT., (© 2016 by The American Society of Hematology.)

Background: Gastrointestinal graft-versus-host-disease (GI-GVHD) is a major cause of nonrelapse mortality after hematopoietic stem cell transplantation (HSCT) necessitating endoscopic examinations and biopsies for diagnosis. Fecal calprotectin (CPT) has been widely used in gastrointestinal inflammation, but comprehensive data in GI-GVHD are lacking., Aims: We aimed to identify an association of CPT with endoscopic findings, mucosal damage and symptoms for diagnosing and monitoring acute GI-GVHD., Methods: Symptoms were prospectively evaluated in 110 consecutive HSCT recipients by standardized questionnaires and Bristol Stool Scale (BSS). CPT was assayed by ELISA. Symptom assessment and CPT were performed weekly and with onset of first symptoms. GVHD was diagnosed according to the Glucksberg criteria and by endoscopic biopsies. Patients with GI-GVHD received standard high-dose corticosteroid therapy and follow-up CPT, and symptom evaluation was performed after 28 days. Patients not responding to steroid treatment were re-evaluated by colonoscopy., Results: GI-GVHD was diagnosed in 40 patients. Twelve patients with GI symptoms and CMV colitis and 24 patients with isolated skin GVHD were included as control subjects. CPT was significantly higher in GI-GVHD compared to skin GVHD and CMV colitis. Endoscopic findings, histological grading, abdominal cramps, diarrhea, urgency and BSS correlated with CPT. At follow-up, CPT correlated with abdominal cramps, diarrhea, urgency and BSS. In steroid refractory patients, CPT level was still significantly associated with severity of mucosal damage., Conclusion: CPT predicts endoscopic and histological findings in GI-GVHD and correlates with lower GI symptoms. It enables to discriminate GVHD from CMV colitis and to monitor therapeutic success.

Hematopoietic stem cell transplantation is a multifactorial process. Some of the predictors exhibit time-dependent effects. We present a systematic analysis and description of selected clinical predictors influencing outcome in a time-dependent manner based on an analysis of registry data from the German Registry for Stem Cell Transplantation. A total of 14,951 patients with acute myeloid leukemia, acute lymphocytic leukemia, myelodysplastic syndrome and non-Hodgkin lymphoma transplanted with peripheral blood stem cells or bone marrow grafts were included. Multivariate Cox regression models were tested for time-dependent effects within each diagnosis group. Predictors not satisfying the proportional hazards assumption were modeled in a time-dependent manner, extending the Cox regression models. Similar patterns occurred in all diagnosis groups. Patients with a poor Karnofsky performance score (<80) had a high risk for early mortality until day 139 following transplantation (HR 2.42, CI: 2.19-2.68; P<0.001) compared to patients with a good Karnofsky performance score (80-100). Afterwards the risk reduced to HR 1.43, CI: 1.25-1.63; P<0.001. A lower mortality risk was found for patients after conditioning treatment with reduced intensity until day 120 post transplant (HR: 0.81 CI: 0.75-0.88; P<0.001). After this, a slightly higher risk could be shown for these patients. Similarly, patients who had received a PBSC graft exhibited a significantly lower mortality risk until day 388 post transplantation (HR 0.79, CI: 0.73-0.85; P<0.001), reversing to a significantly higher risk afterwards (HR 1.23, CI: 1.08-1.40; P=0.002). Integrating time dependency in regression models allows a more accurate description and quantification of clinical predictors to be made, which may help in risk assessment and patient counseling., (Copyright© Ferrata Storti Foundation.)

Acquired chromosomal abnormalities are important prognostic factors in patients with myelodysplastic syndromes treated with supportive care and with disease-modifying therapeutic interventions, including allogeneic hematopoietic stem cell transplantation. To assess the prognostic impact of cytogenetic characteristics after hematopoietic stem cell transplantation accurately, we investigated a homogeneous group of 523 patients with primary myelodysplastic syndromes who have received stem cells from human leukocyte antigen-identical siblings. Overall survival at five years from transplantation in good, intermediate, and poor cytogenetic risk groups according to the International Prognostic Scoring System was 48%, 45% and 30%, respectively (P<0.01). Both the disease status (complete remission vs. not in complete remission) and the morphological classification at transplant in the untreated patients were significantly associated with probability of overall survival and relapse-free survival (P<0.01). The cytogenetic risk groups have no prognostic impact in untreated patients with refractory anemia ± ringed sideroblasts (P=0.90). However, combining the good and intermediate cytogenetic risk groups and comparing them to the poor-risk group showed within the other three disease-status-at-transplant groups a hazard ratio of 1.86 (95%CI: 1.41-2.45). In conclusion, this study shows that, in a large series of patients with primary myelodysplastic syndromes, poor-risk cytogenetics as defined by the standard International Prognostic Scoring System is associated with a relatively poor survival after allogeneic stem cell transplantation from human leukocyte antigen-identical siblings except in patients who are transplanted in refractory anemia/refractory anemia with ringed sideroblasts stage before progression to higher myelodysplastic syndrome stages., (Copyright© Ferrata Storti Foundation.)

Purpose: In the two consecutive German studies III and IIIA on chronic myeloid leukemia, between 1995 and 2004, 781 patients were randomized to receive either allogeneic hematopoietic stem cell transplantation with a related donor or continued drug treatment. Despite comparable transplantation protocols and most centers participating in both studies, the post-transplant survival probabilities for patients transplanted in first chronic phase were significantly higher in study IIIA (144 patients) than in study III (113 patients). Prior to the decision on a combined analysis of both studies, reasons for this discrepancy had to be investigated., Methods: The Cox proportional hazard cure model was used to identify prognostic factors for post-transplant survival., Results: Donor-recipient matching for human leukocyte antigen, patient age, time between diagnosis and transplantation, and calendar time showed a significant influence on survival and/or the incidence of cure. Added as a further factor, affiliation to study IIIA had no significant impact any longer., Conclusions: Discrepancies in influential prognostic factors explained the different post-transplant survival probabilities between the studies. The significance of calendar time suggests a lack of consistency of transplantation practice over time. Accordingly, the prerequisite for a common assessment of overall survival in the two randomized transplantation arms was not met. Moreover, our analyses provide an independent validation of established prognostic factors and their cutoffs. The statistical approach in investigating and modeling potential prognostic factors for survival sets an example for the examination of studies with unexpected outcome differences in concurrent treatment arms.

Purpose: The majority of patients with acute myeloid leukemia (AML) who achieve complete remission (CR) relapse with conventional postremission chemotherapy. Allogeneic stem-cell transplantation (alloSCT) might improve survival at the expense of increased toxicity. It remains unknown for which patients alloSCT is preferable., Patients and Methods: We compared the outcome of 185 matched pairs of a large multicenter clinical trial (AMLCG99). Patients younger than 60 years who underwent alloSCT in first remission (CR1) were matched to patients who received conventional postremission therapy. The main matching criteria were AML type, cytogenetic risk group, patient age, and time in first CR., Results: In the overall pairwise compared AML population, the projected 7-year overall survival (OS) rate was 58% for the alloSCT and 46% for the conventional postremission treatment group (P = .037; log-rank test). Relapse-free survival (RFS) was 52% in the alloSCT group compared with 33% in the control group (P < .001). OS was significantly better for alloSCT in patient subgroups with nonfavorable chromosomal aberrations, patients older than 45 years, and patients with secondary AML or high-risk myelodysplastic syndrome. For the entire patient cohort, postremission therapy was an independent factor for OS (hazard ratio, 0.66; 95% CI, 0.49 to 0.89 for alloSCT v conventional chemotherapy), among age, cytogenetics, and bone marrow blasts after the first induction cycle., Conclusion: AlloSCT is the most potent postremission therapy for AML and is particularly active for patients 45 to 59 years of age and/or those with high-risk cytogenetics.

Background: Owing to its neurotoxicity, allogeneic hematopoietic stem cell transplantation (HSCT) carries risks for cognitive impairment. In this multicenter study, we prospectively evaluated cognitive functioning and its medical and demographic correlates in patients undergoing allogeneic HSCT., Methods: A total of 102 patients were consecutively assessed prior to (T0 ), 100 ± 20 days (T1 ) after, and 12 ± 1 months (T2 ) after HSCT (61% men, 41% acute myeloid leukemia). A comprehensive neuropsychological test battery was applied to evaluate attention, memory, executive function, and fine motor function, summing up into 14 test scores., Results: Before and after HSCT, patients performed below test norms in up to 50% of the test scores. Patients were mostly impaired on word fluency (24%, T0 ), fine motor function, and verbal delayed recall (19% each, T2 ). Impairment on ≥ 1/5 cognitive domains occurred in 47% (T0 ) and 41% (T2 ) of the patients. Performance (mean z-scores) partially improved over time (i.e., visual span forward, verbal learning, and word fluency). However, from baseline to T2 , 16% of the patients showed reliable decline on ≥ 3/14 test scores (reliable change index method). For the majority of neuropsychological subtests, no associations with conditioning intensity, total body irradiation, graft-versus-host disease, cyclosporine treatment, and length of hospital stay were found. Age and premorbid intelligence level were consistently associated with cognition., Conclusions: Below average cognitive performance is common in this patient group. In addition, a subgroup shows reliable cognitive decline after allogeneic HSCT. Healthcare professionals should be aware of these treatment-related cognitive side effects., (Copyright © 2012 John Wiley & Sons, Ltd.)

Patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN) have a poor prognosis with conventional chemotherapy. In the present study, we retrospectively analyzed the outcome of patients with BPDCN who underwent allogeneic stem cell transplantation (allo-SCT) or autologous stem cell transplantation (auto-SCT). A total of 39 patients (allo-SCT, n = 34; auto-SCT, n = 5) were identified in the European Group for Blood and Marrow Transplantation registry. The 34 allo-SCT patients had a median age of 41 years (range, 10-70) and received transplantations from sibling (n = 11) or unrelated donors (n = 23) between 2003 and 2009. MAC was used in 74% of patients. Nineteen allo-SCT patients (56%) received transplantations in first complete remission. The 3-year cumulative incidence of relapse, disease-free survival, and overall survival was 32%, 33%, and 41%, respectively. By univariate comparison, being in first remission at allo-SCT favorably influenced survival, whereas age, donor source, and chronic GVHD had no significant impact. We conclude that high-dose therapy followed by allo-SCT from related or unrelated donors can provide durable remission even in elderly patients with BPDCN. However, it remains to be shown if graft-versus-malignancy effects can contribute significantly to BPDCN control after allo-SCT.

Background: Reduced-intensity conditioning regimens have been developed to minimise early toxic effects and deaths after allogeneic haemopoietic cell transplantation. However, the efficacy of these regimens before this procedure has not been investigated in a randomised trial. In this prospective, open-label randomised phase 3 trial we compared a reduced-intensity fludarabine-based conditioning regimen with a standard regimen in patients with acute myeloid leukaemia in first complete remission., Methods: Patients were aged 18-60 years and had intermediate-risk or high-risk acute myeloid leukaemia (defined by cytogenetics) in first complete remission; an available HLA-matched sibling donor or an unrelated donor with at least nine of ten HLA alleles; and adequate renal, cardiac, pulmonary, and neurological function. Between Nov 15, 2004, and Dec 31, 2009, patients were randomly assigned (1:1, by a computer-based minimisation procedure that balanced patients for age, cytogenetic risk, induction therapy, and donor type) to receive either reduced-intensity conditioning of four doses of 2 Gy of total-body irradiation and 150 mg/m(2) fludarabine or standard conditioning of six doses of 2 Gy of total-body irradiation and 120 mg/kg cyclophosphamide. All patients were given ciclosporin and methotrexate as prophylaxis against graft-versus-host disease. Neither investigators nor patients were blinded to study treatment. Our primary endpoint was the incidence of non-relapse mortality, analysed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00150878., Findings: The trial was stopped early on Dec 31, 2009, because of slow accrual of patients. 99 patients were randomly assigned to receive reduced-intensity conditioning and 96 to receive standard conditioning. The incidence of non-relapse mortality did not differ between the reduced-intensity and standard conditioning groups (cumulative incidence at 3 years 13% [95% CI 6-21] vs 18% [10-26]; HR 0·62 [95% CI 0·30-1·31]). Relapse incidence (cumulative incidence 3 years 28% [95% CI 19-38] vs 26% [17-36]; HR 1·10 [95% CI 0·63-1·90]), disease-free survival (3 year disease-free survival 58% [95% CI 49-70] vs 56% [46-67]; HR 0·85 [95% CI 0·55-1·32]), and overall survival (3 year overall survival 61% [95% CI 50-74] vs 58% [47-70]; HR 0·77 [95% CI 0·48-1·25]) did not differ significantly between groups. Grade 3-4 of oral mucositis was less common in the reduced-intensity group than in the standard conditioning group (50 patients in the reduced-intensity conditioning group vs 73 patients in the standard conditioning group); the frequency of other side-effects such as graft-versus-host disease and increased concentrations of bilirubin and creatinine did not differ significantly between groups., Interpretation: Reduced-intensity conditioning results in a similar incidence of non-relapse mortality and reduced toxic effects compared with standard conditioning without affecting survival outcomes, and thus could be preferentially used in patients younger than 60 years with acute myeloid leukaemia transplanted in first complete remission., (Copyright © 2012 Elsevier Ltd. All rights reserved.)