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Second allogeneic stem cell transplantation (alloSCT2) is among the most effective treatments for acute myeloid leukemia (AML) relapse after first alloSCT (alloSCT1). Long-term EBMT registry data were used to provide large scale, up-to-date outcome results and to identify factors for improved outcome. Among 1540 recipients of alloSCT2, increasing age, better disease control and performance status before alloSCT2, more use of alternative donors and higher conditioning intensity represented important trends over time. Between the first (2000–2004) and last (2015–2019) period, two-year overall and leukemia-free survival (OS/LFS) increased considerably (OS: 22.5–35%, LFS: 14.5–24.5%). Cumulative relapse incidence (RI) decreased from 64% to 50.7%, whereas graft-versus-host disease and non-relapse mortality (NRM) remained unchanged. In multivariable analysis, later period of alloSCT2 was associated with improved OS/LFS (HR = 0.47/0.53) and reduced RI (HR = 0.44). Beyond, remission duration, disease stage and patient performance score were factors for OS, LFS, RI, and NRM. Myeloablative conditioning for alloSCT2 decreased RI without increasing NRM, leading to improved OS/LFS. Haploidentical or unrelated donors and older age were associated with higher NRM and inferior OS. In summary, outcome after alloSCT2 has continuously improved over the last two decades despite increasing patient age. The identified factors provide clues for the optimized implementation of alloSCT2. [ABSTRACT FROM AUTHOR]

To determine factors influencing the vaccination response against SARS-CoV-2 is of importance in recipients of allogeneic hematopoietic cell transplantation (allo-HCT) as they display an increased mortality after SARS-CoV-2 infection, an increased risk of extended viral persistence and reduced vaccination response. Real-life data on anti-SARS-CoV-2-S1-IgG titers (n = 192) and IFN-γ release (n = 110) of allo-HCT recipients were obtained using commercially available, validated assays after vaccination with either mRNA (Comirnaty™, Pfizer-BioNTech™, NY, US and Mainz, Germany or Spikevax™, Moderna™, Cambridge, Massachusetts, US) or vector-based vaccines (Vaxzevria™,AstraZeneca™, Cambridge, UK or Janssen COVID-19 vaccine™Johnson/Johnson, New Brunswick, New Jersey, US), or after a heterologous protocol (vector/mRNA). Humoral response (78% response rate) was influenced by age, time after transplantation, the usage of antithymocyte globulin (ATG) and ongoing immunosuppression, specifically corticosteroids. High counts of B cells during the vaccination period correlated with a humoral response. Only half (55%) of participants showed a cellular vaccination response. It depended on age, time after transplantation, ongoing immunosuppression with ciclosporin A, chronic graft-versus-host disease (cGvHD) and vaccination type, with vector-based protocols favoring a response. Cellular response failure correlated with a higher CD8+ count and activated/HLA-DR+ T cells one year after transplantation. Our data provide the basis to assess both humoral and cellular responses after SARS-CoV2 vaccination in daily practice, thereby opening up the possibility to identify patients at risk. [ABSTRACT FROM AUTHOR]

We report a single-center phase I/II trial exploring the combination of everolimus (EVE) and mycophenolate mofetil (MMF) as calcineurin inhibitor (CNI)-free GVHD prophylaxis for 24 patients with hematologic malignancies and indication for allogeneic HCT after a high dose or reduced-intensity ablative conditioning. The study was registered as EudraCT-2007-001892-12 and Clinicaltrials.gov as NCT00856505. All patients received PBSC grafts and no graft failure occurred. 7/24 patients (29%) developed acute grades III and IV GVHD (aGVHD), 16/19 evaluable patients (84%) developed chronic GVHD (cGVHD) of all grades, and 6/19 (31.6%) of higher grades. No severe toxicities related to study medication were observed. The median follow-up of all surviving patients is 2177 days. The 3-year OS was 45.2% (95% CI: 27.4–61.4%), and the 3-year PFS was 38.7% (95% CI: 22.0–55.1%). The cumulative incidence of relapse at 1 year and 3 year was 25% (95% CI: 12.5–50.0%), and 33.3% (95% CI: 18.9–58.7%), the cumulative incidence of NRM at 1 year and 3 years was 20.8% (95%CI: 9.6–45.5%), and 29.2% (95%CI: 15.6–54.4%), respectively. The utilization of CNI-free GVHD prophylaxis with EVE+MMF resulted in high rates of acute and chronic GVHD. Therefore, we do not recommend a CNI-free combination of mTOR inhibitor EVE with MMF as the sole GVHD prophylaxis. In subsequent studies, this combination should be modified, e.g., with further components like post-transplant cyclophosphamide (PTCy) or anti-thymocyte globulin (ATG). [ABSTRACT FROM AUTHOR]

Summary: Although second allogeneic haematopoietic cell transplantation (allo‐HCT2) is a therapeutic option for patients relapsing after first HCT (allo‐HCT1), there is limited data on allo‐HCT2 in patients with acute lymphoblastic leukaemia (ALL). We retrospectively studied 245 patients receiving allo‐HCT2 as a salvage treatment for relapse following allo‐HCT1 between the 2000 and 2017. The median age at allo‐HCT2 was 34·6 years (range: 18–74). One hundred and one patients (41%) received sibling donor and 144 (59%) unrelated donor allo‐HCT2. Acute graft‐versus‐host disease (GVHD) grade II–IV and III–IV occurred in 33% and 17% of the patients, respectively. The incidence of 2‐year total and extensive chronic GVHD was 38% and 19%, respectively. The 2‐ and 5‐year cumulative incidence of non‐relapse mortality, relapse incidence, leukaemia‐free survival, overall survival and GVHD‐free, relapse‐free survival (GRFS) were 24% and 26%, 56% and 62%, 20% and 12%, 30% and 14% and 12% & 7%, respectively. In multivariate analysis, factors associated with overall survival were age, time from allo‐HCT1 to relapse, conditioning for allo‐HCT1, Karnofsky score at allo‐HCT2 and donor type for allo‐HCT2. In conclusion, outcomes of allo‐HCT2 in ALL patients were poor, with only 14% overall survival and 7% GRFS at 5 years with very high relapse incidence. [ABSTRACT FROM AUTHOR]

Background: Minimal residual disease (MRD) and hematopoietic chimerism testing influences clinical decision and therapeutic intervention in patients after allogeneic stem cell transplantation (HSCT). However, treatment approaches to induce complete donor chimerism and MRD negativity can lead to complications such as graft-versus-host disease (GvHD) and marrow aplasia. Therefore, there is a need for comprehensive characterization of the molecular remission status after transplantation. Methods: We analyzed 764 samples from 70 patients after HSCT for the simultaneous measurement of chimerism and molecular targets used for MRD testing with a digital PCR (dPCR) platform. Results: Mixed chimerism (MC) was detected in 219 samples from 37 patients. The mean percentage of host derived DNA in these clinical samples was 4.3%. Molecular relapse with a positive MRD marker and/or increased WT1 expression was observed in 15 patients. In addition to WT1 overexpression, other MRD positive markers were: NPM1 (Type A, B, K), DNMT3A (R882H), MLL-PTD, IDH1 (R132H) and KRAS (G12S). Increasing MC was observed in 15 patients. This group of patients showed either a positive MRD marker, increased WT1 expression or both. Next, we analyzed whether MC or the molecular target for MRD was first detected. MC and MRD marker positivity in this group was first detected in six and two patients, respectively. In the remaining seven patients MC and MRD positivity was detected simultaneously. Conclusions: The combination of MRD and chimerism markers in a dPCR platform represents a practical, sensitive and accurate diagnostic tool for the comprehensive assessment of the molecular remission status of patients undergoing HSCT. [ABSTRACT FROM AUTHOR]

Background: Graft-versus-Host Disease (GvHD) causes significant morbidity and mortality in patients after allogeneic stem cell transplantation. Donor T-cells cause inflammation and tissue damage in GvHD target organs such as liver, gut and skin. Cytokine receptor associated kinases JAK1 and JAK2 are critical for inflammatory cytokine response in GvHD. Ruxolitinib is a small molecule inhibitor of JAK1 and JAK2. Preliminary data indicated substantial clinical activity in patients with steroid-refractory (SR) acute and chronic GvHD.Methods: The RIG-study is an investigator-initiated open-label, multicenter, prospective randomized controlled two-arm phase 2 study, comparing the efficacy of ruxolitinib and best available treatment (BAT) versus BAT in steroid-refractory acute GvHD (SR-aGvHD). Patients with acute skin, intestinal or liver GvHD > grade 1 and failure of previous treatment are eligible. The trial aims to include 160 patients who will be randomized in a 1:1 ratio and stratified by GvHD grade (≤ grade 3 versus grade 4) and number of previous immunosuppressive treatments (≤ 3 versus ≥4). The primary endpoint is the overall response rate at day 28, defined as: Improvement of at least one stage in the severity of acute GvHD in one organ without deterioration in any other organ, or disappearance of any GvHD signs from all organs without requirement for new systemic immunosuppressive treatment. Secondary objectives include time to response, overall survival, event-free survival, non-relapse mortality (NRM), failure-free survival, graft failure rates, quality of life and changes in serum levels of pro-inflammatory cytokines and GvHD-related biomarkers.Discussion: This randomized prospective trial will provide further evidence if the retrospectively collected data demonstrating activity of ruxolitinib for SR-aGvHD can be reproduced. A major advantage of ruxolitinib might be the limited and predictable toxicity profile compared to other immunosuppressive therapies that mainly includes viral reactivation and cytopenias. This trial will establish candidate biomarkers to predict and monitor responses to ruxolitinib. As a next step ruxolitinib might be tested upfront against steroids or in a preemptive manner to prevent GvHD to occur.Trial Registration: NCT02396628 (registration date 17.07.2015); DRKS00007939 (registration date 26.03.2015). [ABSTRACT FROM AUTHOR]

Background: Clinical decision making after allogeneic stem cell transplantation (HSCT) is partially based on hematopoietic chimerism analysis. Polymerase chain reaction amplification of polymorphic short tandem repeats (STR-PCR) is currently considered the gold standard for chimerism surveillance after transplantation. Nevertheless, this method has shown several limitations. Emerging technologies such as digital PCR (dPCR) has been applied to detect hematopoietic chimerism. Despite previous reports, the clinical usefulness of dPCR is unclear because the studies were performed in limited patient populations with short follow-ups. Methods: In order to compare hematopoietic chimerism detection time and rate, we analyzed 591 samples from 155 patients undergoing gender-mismatched HSCT using STR-PCR and dPCR. We also established the correlation between both methods in artificial DNA mixtures prepared in known proportions and in clinical samples. Results: Depending on the artificial DNA mixture analyzed the correlation coefficient between both methods was 0.9946 and 0.9732. The limit of detection for dPCR was 0.01%. Of 157 samples with donor and recipient DNA, mixed chimerism (MC) was detected solely by dPCR in 66 samples. Within the group of patients relapsing after HSCT (n = 32) MC was detected earlier in 15 of these patients with dPCR in comparison with STR-PCR. The mean time from MC detection to relapse was 155 days (range: 13�5 days) and 65 days (range: 0�3 days) for dPCR and STR-PCR, respectively. Conclusions: dPCR is a sensitive and accurate method for the quantification of hematopoietic chimerism allowing earlier MC detection compared to STR-PCR. [ABSTRACT FROM AUTHOR]

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment option for myelofibrosis (MF) despite the emergence of novel targeted therapies. To reduce graft rejection and graft-versus-host disease (GvHD), current allo-HCT protocols often include in vivo T lymphocyte depletion using polyclonal anti-thymocyte globulin (ATG). Shortly after ATG administration, an immediate inflammatory response with fever, chills, and laboratory alterations such as cytopenias, elevation of serum C-reactive protein, bilirubin, and transaminases can develop. Here, we explore whether MF patients, who commonly exhibit extramedullary hematopoiesis in the liver, might be particularly susceptible to ATG-induced liver toxicity. To test this hypothesis, we analyzed 130 control and 94 MF patients from three transplant centers treated with or without ATG during the allo-HCT conditioning regimen. Indeed, hyperbilirubinemia was found in nearly every MF patient treated with ATG (MF-ATG 54/60 = 90 %) as compared to non-ATG treated MF (MF-noATG 15/34 = 44.1 %, p < 0.001) and respectively ATG-treated non-MF patients of the control group (control-ATG, 43/77 = 56 %, p < 0.001). In contrast, transaminases were only inconsistently elevated. Hyperbilirubinemia was in most cases self-limiting and not predictive of increased incidence of non-relapse mortality, hepatic sinusoidal obstruction syndrome (SOS) or liver GvHD. In sum, awareness of this stereotypic bilirubin elevation in MF patients treated with ATG provides a relatively benign explanation for hyperbilirubinemia occurring in these patients during the early transplant. However, attention to drug levels of biliary excreted drugs is warranted, since altered bile flow may influence their clearance and enhance toxicity (e.g., busulfan, antifungal agents). [ABSTRACT FROM AUTHOR]

Background: Rabbit polyclonal anti-T-lymphocyte Globulin ( ATG-F®, Fresenius) is widely used for GvHD prophylaxis in allogeneic stem cell transplantation (SCT). ATG has a wide epitope spectrum and has been shown to react with all compartments of peripheral blood mononuclear cells (PBMNCs). ATG induces apoptosis in all cellular compartments. In this study we investigated the binding of ATG in sera from ten patients treated with rabbit ATG to PBMNCs and subcellular compartments after full hematopoetic regeneration on day 21 post SCT. Methods: Sera from ten patients treated with unrelated donor allogeneic SCT for hematologie malignancy were collected after full hematopoetic regeneration on day 21 post SCT and incubated with healthy donor PBMNCs. Rabbit ATG on PBMNCs was detected by staining with fluorochrome labeled anti-rabbit igG antibody. PBMNC compartments were investigated by counterstaining with lineage markers CD4, CD8, CD14 CD20 and CD56. Positive control was the fresh ATG preparation. Results: We found that patient's' sera retained activity towards PBMNCs in all patients, yet at reduced intensity. When cell compartments were analyzed we found a differential pattern of ATG reactivity within sera. The mean percentage of total cells reacting with serum ATG from ten patients compared to fresh ATG (100%) was 44% of CD4 positive and 58% of CD8 positive T-lymphocytes, 41% of CD56 positive NK-cells, 83% of CD20 positive B-lymphocytes and 98% of CD14 positive monocytes. However, inter-individual variations were high with a wide spread around the mean especially for T-lymphocytes. Conclusion: We conclude that upon PBMNC regeneration following SCT and immunosuppressive treatment with ATG subpopulations of T-lymphocytes (CD4, CD8) and NK cells (CD56) are selected that lose epitopes recognized by ATG while B-lymphocytes (CD20) and monocytes (CD14) maintain a homogeneity with respect to epitopes recognized by ATG. This may be due to loss of idiotypes reacting with subpopulations of high frequency and turnover. Further studies should investigate the subphenotype of these populations and functional effects of extremely high or low reactivity with one or more compartments in some patients on GvHD and disease outcome. [ABSTRACT FROM AUTHOR]

Allogeneic hematopoietic cell transplantation (HCT) is a curative approach for several diseases predominantly affecting elderly patients. Overall survival is compromised by treatment-related mortality (TRM), GvHD, and relapse. Pretransplant clinical risk indicators in elderly patients qualifying for HCT are highly desirable. Pro-BNP is known as a predictor of death in patients with an increasing variety of clinical conditions and frequently used as a routine parameter for organ complications in the allogeneic transplant setting without well-established scientific evidence. Our hypothesis was that pre-HCT NT-pro-BNP could aid in identifying elderly patients at risk for early mortality. We retrospectively evaluated NT-pro-BNP values in 177 consecutive patients of ≥60 years HCT (2005-2010). In 29.4 % of cases, NT-pro-BNP values were within our institute's normal range (<125 pg/ml). Analysis of different NT-pro-BNP cutoff points by receiver operating characteristics curve for mortality at day +100 revealed no single cutoff value with satisfying specificity and sensitivity. The individual outcome of patients with extremely high NT-pro-BNP values was not associated with an increase in mortality or cardiovascular morbidity. NT-pro-BNP values of patients succumbing to TRM did not differ significantly from those alive or having died of relapse-median 276 vs. 217 pg/ml. In conclusion, pre-HCT NT-pro-BNP was of no convincing prognostic relevance for day 100 mortality. [ABSTRACT FROM AUTHOR]

Several prognostic factors for the outcome after allogeneic hematopoietic stem-cell transplant (HSCT) from matched unrelated donors have been postulated from registry data; however, data from randomized trials are lacking. We present analyses on the effects of patient-related, donor-related, and treatment-related prognostic factors on acute GVHD (aGVHD), chronic GVHD (cGVHD), relapse, nonrelapse mortality (NRM), disease-free survival (DFS), and overall survival (OS) in a randomized, multicenter, open-label, phase III trial comparing standard graft-versus-host-disease (GVHD) prophylaxis with and without pretransplantation ATG-Fresenius (ATG-F) in 201 adult patients receiving myeloablative conditioning before HSCT from HLA-A, HLA-B antigen, HLA-DRB1, HLA-DQB1 allele matched unrelated donors. High-resolution testing (allele) of HLA-A, HLA-B, and HLA-C were obtained after study closure, and the impact of an HLA 10/10 4-digit mismatch on outcome and on the treatment effect of ATG-F versus control investigated. Advanced disease was a negative factor for relapse, DFS, and OS. Donor age ≥40 adversely affected the risk of aGVHD III-IV, extensive cGVHD, and OS. Younger donors are to be preferred in unrelated donor transplantation. Advanced disease patients need special precautions to improve outcome. The degree of mismatch had no major influence on the positive effect of ATG-F on the reduction of aGVHD and cGVHD. [ABSTRACT FROM AUTHOR]

Danger signals released upon cell damage can cause excessive immune-mediated tissue destruction such as that found in acute graft-versus-host disease (GVHD), allograft rejection and systemic inflammatory response syndrome. Given that ATP is found in small concentrations in the extracellular space under physiological conditions, and its receptor P2X7R is expressed on several immune cell types, ATP could function as a danger signal when released from dying cells. We observed increased ATP concentrations in the peritoneal fluid after total body irradiation, and during the development of GVHD in mice and in humans. Stimulation of antigen-presenting cells (APCs) with ATP led to increased expression of CD80 and CD86 in vitro and in vivo and actuated a cascade of proinflammatory events, including signal transducer and activator of transcription-1 (STAT1) phosphorylation, interferon-γ (IFN-γ) production and donor T cell expansion, whereas regulatory T cell numbers were reduced. P2X7R expression increased when GVHD evolved, rendering APCs more responsive to the detrimental effects of ATP, thereby providing positive feedback signals. ATP neutralization, early P2X7R blockade or genetic deficiency of P2X7R during GVHD development improved survival without immune paralysis. These data have major implications for transplantation medicine, as pharmacological interference with danger signals that act via P2X7R could lead to the development of tolerance without the need for intensive immunosuppression. [ABSTRACT FROM AUTHOR]

Summary: Background: Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality after allogeneic haematopoietic cell transplantation from unrelated donors. Anti-T-cell globulins (ATGs) might lower the incidence of GVHD. We did a prospective, randomised, multicentre, open-label, phase 3 trial to compare standard GVHD prophylaxis with ciclosporin and methotrexate with or without anti-Jurkat ATG-Fresenius (ATG-F). Methods: Between May 26, 2003, and Feb 8, 2007, 202 patients with haematological malignancies were centrally randomly assigned using computer-generated centre-stratified block randomisation between treatment groups receiving ciclosporin and methotrexate with or without additional ATG-F. One patient in the ATG-F group did not undergo transplantation, thus 201 patients who underwent transplantation with peripheral blood (n=164; 82%) or bone marrow (n=37; 18%) grafts from unrelated donors after myeloablative conditioning were included in the full analysis set, and were analysed according to their randomly assigned treatment (ATG-F n=103, control n=98). The primary endpoint was severe acute GVHD (aGVHD) grade III–IV or death within 100 days of transplantation. The trial is registered with the numbers DRKS00000002 and NCT00655343. Findings: The number of patients in the ATG-F group who had severe aGVHD grade III–IV or who died within 100 days of transplantation was 12 and 10 (21·4%, 95% CI 13·4–29·3), respectively, compared with 24 and nine (33·7%, 24·3–43·0) patients, respectively, in the control group (adjusted odds ratio 0·59, 95% CI 0·30–1·17; p=0·13). The cumulative incidence of aGVHD grade III–IV was 11·7% (95% CI 6·8–19·8) in the ATG-F group versus 24·5% (17·3–34·7) in the control group (adjusted hazard ratio [HR] 0·50, 95% CI 0·25–1·01; p=0·054), and cumulative incidence of aGVHD grade II–IV was 33·0% (n=34; 95% CI 25·1–43·5) in the ATG-F group versus 51·0% (n=50; 95% CI 42·0–61·9) in the control group (adjusted HR 0·56, 0·36–0·87; p=0·011). The 2-year cumulative incidence of extensive chronic GVHD was 12·2% (n=11; 95% CI 7·0–21·3) versus 42·6% (n=34; 95% CI 33·0–55·0; adjusted HR 0·22, 0·11–0·43; p<0·0001). There were no differences between treatment groups with regard to relapse, non-relapse mortality, overall survival, and mortality from infectious causes. Interpretation: The addition of ATG-F to GVHD prophylaxis with ciclosporin and methotrexate resulted in decreased incidence of acute and chronic GVHD without an increase in relapse or non-relapse mortality, and without compromising overall survival. The use of ATG-F is safe for patients who are going to receive a haematopoietic cell transplantation from matched unrelated donors. Funding: Fresenius Biotech GmbH. [Copyright &y& Elsevier]

Simple Summary: Due to its graft-versus-myeloma effect, allogeneic hematopoietic stem cell transplantation (allo-SCT) can enable long-term survival or even cure in carefully selected patients with multiple myeloma (MM), but remains controversial due to its relevant treatment-related toxicity. Current data suggest that allo-SCT should be considered in young MM-patients without relevant comorbidities in case of a high-risk constellation according to cytogenetics or stage, primarily as part of a tandem approach with autologous-SCT followed by allo-SCT and early in the course of the disease. Prospective studies are warranted, due to a suspected synergism especially those including new immunotherapeutic approaches for induction, conditioning and maintenance therapy. The development of new inhibitory and immunological agents and combination therapies significantly improved response rates and survival of patients diagnosed with multiple myeloma (MM) in the last decade, but the disease is still considered to be incurable by current standards and the prognosis is dismal especially in high-risk groups and in relapsed and/or refractory patients. Allogeneic hematopoietic stem cell transplantation (allo-SCT) may enable long-term survival and even cure for individual patients via an immune-mediated graft-versus-myeloma (GvM) effect, but remains controversial due to relevant transplant-related risks, particularly immunosuppression and graft-versus-host disease, and a substantial non-relapse mortality. The decreased risk of disease progression may outweigh this treatment-related toxicity for young, fit patients in high-risk constellations with otherwise often poor long-term prognosis. Here, allo-SCT should be considered within clinical trials in first-line as part of a tandem approach to separate myeloablation achieved by high-dose chemotherapy with autologous SCT, and following allo-SCT with a reduced-intensity conditioning to minimize treatment-related organ toxicities but allow GvM effect. Our review aims to better define the role of allo-SCT in myeloma treatment particularly in the context of new immunomodulatory approaches. [ABSTRACT FROM AUTHOR]

Acute graft-versus-host disease (GVHD) is a primary T-cell-mediated complication of allogeneic hematopoietic stem cell transplantation (HSCT), occurring when donor-derived T cells are stimulated by host antigen-presenting cells (APCs), enhanced by proinflammatory cytokines such as interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha. Recent data indicate that besides differences in major histocompatibility and minor histocompatibility antigens, cytokine gene polymorphisms have a predictive value for the complication of GVHD. Patients with a high anti-inflammatory IL-10 production have been demonstrated to be protected from GVHD while patients with high TNF-alpha serum levels were more at risk for GVHD. Pharmacological immunosuppression for GVHD prophylaxis and therapy, including unspecific approaches with corticosteroids or methotrexate (MTX), as well as more specific therapy with cyclosporin A (CsA), tacrolimus (FK506), sirolimus, mycophenolate mofetil (MMF), antithymocyte globulin (ATG), and monoclonal antibodies (MAbs) directed against CD3, CD25, CD52, cytotoxic T-lymphocyte antigen (CTLA)-4, CD40 ligand, or TNF-alpha, have been proven to be effective. Recent data on novel techniques to selectively deplete alloreactive T cells by removal, destruction, or anergy induction while preserving leukemia-specific T-cell clones suggest a clinical benefit from these approaches. Gene-modified T cells that can selectively be depleted and CD4+CD25+ regulatory T cells are under investigation for their ability to modulate alloreactivity after HSCT. With a better understanding of the immunopathogenesis of acute GVHD and the technical improvement of recently described therapeutic approaches, such as removal of naive T cells, selection of Th2 cells, suicide gene transduced T cells, and adoptive transfer of regulatory T cells, the use of alloreactivity as a treatment modality may be expanded to nonhematological disease entities such as solid tumors or autoimmune disorders. [ABSTRACT FROM AUTHOR]

Abstract: Aims: Veno-occlusive disease of the liver is a severe complication of allogeneic bone marrow or peripheral stem cell transplantation with a high mortality. In its severe form, the portal vein is used as an outflow tract for the arterial hepatic perfusion. A portosystemic side-to-side shunt, e.g. a transjugular intrahepatic portosystemic shunt, may facilitate portal outflow thus increasing hepatic (i.e. arterial) perfusion. Methods: The effect of a transjugular shunt on liver function and blood flow was studied in three patients receiving shunt treatment 0–2 days after the diagnosis of severe veno-occlusive disease occurring 28, 20, and 17 days after allogeneic transplantation for acute myeloid leukemia, Hodgkin’s disease and chronic myeloid leukemia, respectively. Results: The transjugular shunt reduced the portosystemic pressure gradient from 23 to 8, 18 to 5, and 33 to 13 mmHg in patients 1, 2, and 3, respectively, increased the stagnant portal vein flow to normal, and decreased the arterial resistive index, indicating an increase in the arterial perfusion of the liver. This was accompanied by rapid relief from abdominal pain and removal of ascites. The AST concentration dropped from 1230, 417, and 2930 U/l before to 93, 20, and 41 U/l and the PT-time ratio improved 3–7 days after shunt treatment while the bilirubin concentration continued to rise until the patients died 26, 42, and 33 days after transplantation from multiorgan failure (two patients) or intracerebral hemorrhage. Conclusions: The transjugular shunt may have improved abdominal and hepatic perfusion and prevented further necrosis of hepatocytes. It did not, however, affect jaundice or survival, which was limited by extrahepatic complications. [ABSTRACT FROM AUTHOR]

In the light of reduced intensity conditioning regimens for allogeneic transplantation, monitoring of donor cell engraftment acquires new relevance. We analysed the clinical significance of haematopoietic chimaerism as a parameter of patient outcome and detection of relapse for early intervention by donor lymphocyte infusion (DLI) after allogeneic transplantation. Between July 1994 and March 1999, 101 adult patients with malignant disease were evaluated. Median follow-up was 15 months (range 0·7–56·5) after transplantation. Patients received busulphan-containing (n = 82) or total body irradiation (TBI)-containing (n = 19) regimens. Fifteen out of 98 (15%) patients with predictive chimaerism analyses relapsed, 5 out of 20 (25%) with mixed chimaerism (MC) and 10 out of 78 (13%) with complete donor chimaerism (CC) before apparent relapse. Seven patients received donor lymphocyte infusions (DLI) as relapse therapy with conversion from MC to CC in all three patients with successful DLI. Our data stress the importance of chimaerism monitoring after allogeneic transplantation and demonstrate the more frequent occurrence of disease relapse in patients showing MC, rather than CC, after transplantation. Moreover, the assessment of chimaerism has been shown to be a valuable tool in monitoring the efficiency of donor lymphocyte infusions for relapse. [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal/liver graft-vs.-host disease is a frequent complication after allogeneic hematopoietic cell transplantation. Endoscopic biopsies are needed to confirm clinical diagnosis, but this is not always feasible due to concurrent complications after transplantation. Cytokeratin 18 is expressed in epithelial colon cells and hepatocytes. Apoptosis, a hallmark of graft-vs.-host disease, results in the cleavage of cytokeratin 18 and the resulting fragments are released into the circulation. Methods: The aim of the present study was to assess the general performance and usefulness of a serologic test for soluble cytokeratin 18 for gastrointestinal/liver graft-vs.-host disease detection. Plasmatic concentration of soluble cytokeratin 18 was measured in 38 individuals undergoing hematopoietic cell transplantation. A two-fold increase of sCK18 above the pre-transplant concentration was used as a threshold value. Results: Plasmatic concentration of soluble cytokeratin 18 was significantly elevated in patients with gastrointestinal/liver graft-vs.-host disease. Soluble cytokeratin 18 concentration raised before the onset of clinical symptoms in 69% of the patients with gastrointestinal/liver graft-vs.-host disease. The threshold value used in our study resulted in a high sensitivity and a low false negative rate for gastrointestinal/liver graft-vs.-host disease detection. Conclusions: Soluble cytokeratin 18 seems to be a suitable biomarker for gastrointestinal/liver graft-vs.-host disease detection, particularly when a biopsy is not feasible. [ABSTRACT FROM AUTHOR]

• Relapse- and immunosuppression-free survival were novel endpoints after transplant. • These endpoints were formulated and statistically analyzed by multistate methodology and resampling. • A randomized clinical trial was conducted on GVHD prophylaxis. • The difference between treatment groups was estimated as approximately 30% over 8 years. • An R code was provided to promote our methods to the transplant community. In most clinical oncology trials, time-to-first-event analyses are used for efficacy assessment, which often do not capture the entire disease process. Instead, the focus may be on more complex time-to-event endpoints, such as the course of disease after the first event or endpoints occurring after randomization. We propose "relapse- and immunosuppression-free survival" (RIFS) as an innovative and clinically relevant outcome measure for assessing treatment success after hematopoietic stem cell transplant (SCT). To capture the time-dynamic relationship of multiple episodes of immunosuppressive therapy during follow-up, relapse, and nonrelapse mortality, a multistate model was developed. The statistical complexity is that the probability of RIFS is nonmonotonic over time; thus, standard time-to-first-event methodology is inappropriate for formal treatment comparisons. Instead, a generalization of the Kaplan-Meier method was used for probability estimation, and simulation-based resampling was suggested as a strategy for statistical inference. We reanalyzed data from a recently published phase III trial in 201 leukemia patients after SCT. The study evaluated long-term treatment success of standard graft-versus-host disease prophylaxis plus a pretransplant antihuman T-lymphocyte immunoglobulin compared with standard prophylaxis alone. Results suggested that treatment increased the long-term probability of RIFS by approximately 30% during the entire follow-up period, which complements the original findings. This article highlights the importance of complex endpoints in oncology, which provide deeper insight into the treatment and disease process over time. Multistate models combined with resampling are highlighted as a promising tool to evaluate treatment success beyond standard endpoints. An example code is provided in the Supplementary Materials. [ABSTRACT FROM AUTHOR]

Background aims. The anti-CD52 monoclonal antibody alemtuzumab is employed in allogeneic hematopoietic cell transplantation (alloHCT) for the prevention of graft-versus-host disease (GVHD). However, its optimal dosing in this setting has not been determined yet. We compared three different alemtuzumab dose levels in reduced intensity conditioning (RIC) alloHCT with respect to lymphocyte recovery and outcome. Methods. In 127 consecutive patients with predominantly advanced stage hematologic malignancies, a first alloHCT after RIC was performed, applying a fludarabine-based protocol (in 93% FBM: fludarabine, bis-chloroethyl-nitrosourea [BCNU], and melphalan). For GVHD prophylaxis, cyclosporine and alemtuzumab at three different dose levels (40 mg, 20 mg, 10 mg) were administered. Recovery of the peripheral blood (PB) lymphocyte sub-populations and clinical outcome were determined with regard to the alemtuzumab dose. Results. Natural killer (NK) cell concentrations in PB around day +30 correlated inversely with the alemtuzumab dose, whereas other PB lymphocyte subtypes remained essentially unaffected by dosing of alemtuzumab. Lower alemtuzumab doses were associated with a tendency toward improved overall survival mainly during the early post-transplantation months. With regard to the PB NK cell concentration around day +30, "early intense NK cell reconstituters" tended to show an overall survival benefit. Conclusions. An alemtuzumab dose reduction to only 10-20 mg provides sufficient GVHD prophylaxis and supports improved NK cell regeneration early after alloHCT in PB ("NK cell saving effect"), which may have a positive effect on overall survival. [ABSTRACT FROM AUTHOR]

Chronic graft-versus-host disease (cGVHD) frequently involves oral tissues. Although the mucosal changes may be painful and impair oral function, there is currently no topical therapy available for oral cGVHD that has been proven to work in an evidence-based manner. The aims of this study were to (1) assess the response of patients with oral cGVHD to various doses of a new topical budesonide formulation; (2) evaluate the efficacy and safety of the new topical budesonide formulation in these patients. An open, randomized, multicenter phase II pilot study with 4 treatment arms differing in application frequency and duration was performed. Response to treatment was scored by the clinician and patient using several scales. Oral cGVHD improved in all patients, with a median reduction of 70%. Pain reduction was similar in all study arms. The rate of objective improvement (defined as ≥50%) was not significantly different among the 4 study arms. The safety profile was satisfactory. Topical budesonide mouthwash (3 mg/10 mL) improved oral cGVHD in all patients when applied for 5 or 10 minutes, 2 or 3 times daily. The response was similar in all treatment arms. Safety analysis supported a dosing schedule of 3 mg of budesonide 3 times a day for 10 minutes. [ABSTRACT FROM AUTHOR]

• FLAMSA (fludarabine, Ara-C, and amsacrine) sequential chemotherapy followed by total body irradiation (TBI)-based reduced-intensity conditioning (RIC) and myeloablative conditioning (MAC) led to similar transplantation outcomes in relapsed/refractory active acute myeloid leukemia. • FLAMSA sequential chemotherapy followed by TBI-free RIC was associated with lower nonrelapse mortality resulting in increased overall survival. • There were no significant differences in relapse incidence between FLAMSA sequential chemotherapy followed by RIC and MAC. The use of myeloablative conditioning (MAC) in the setting of active relapsed/refractory (R/R) acute myeloid leukemia (AML) has been hindered by high historical rates of nonrelapse mortality (NRM). FLAMSA (fludarabine, Ara-C, and amsacrine) chemotherapy (CT) followed by reduced-intensity conditioning (RIC) has been proposed as an effective and potentially safer alternative in this scenario. As improvements in supportive care have contributed to decreasing NRM rates after MAC, a comparative reassessment of these two strategies was performed. This was a registry-based analysis by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation. Eligibility criteria included age 18 to 50 years, primary refractory, first or second relapsed active AML, first allogeneic stem cell transplantation from a matched sibling donor (MSD) or an unrelated donor (UD) performed between 2005 and 2018, MAC or FLAMSA-RIC. A total of 1018 patients were included. The median patient age was 39 years (range, 18 to 50). Two hundred and fifty-eight patients received busulfan (Bu)/cyclophosphamide (Cy), 314 received Cy/total body irradiation (TBI), 318 received FLAMSA-TBI, and 128 received FLAMSA-CT. The median duration of follow-up was 50 months. In univariate analysis, the 2-year relapse incidence (RI) (54%; 95% confidence interval (CI), 50%-57%), leukemia-free survival (LFS) (30%; 95% CI, 27%-33%), and refined graft-versus-host disease-free, relapse-free survival (GRFS) (21%; 95% CI, 18%-24%) were not significantly different between cohorts. Lower 2-year NRM was observed in the FLAMSA-CT group (7% versus 16% in Bu/Cy, 19% in Cy/TBI, and 18% in FLAMSA-TBI; P =.04), as well as increased 2-year overall survival (OS) (50% versus 33% in Bu/Cy, 34% in Cy/TBI, and 36% in FLAMSA-TBI; P =.03). These results were maintained in the multivariate analysis (hazard ratio [HR] for NRM:.40, P =.01; HR for OS:.65, P =.01; Bu/Cy as reference). These data suggest that FLAMSA-CT may be a preferred conditioning regimen in patients with active R/R AML due to lower NRM. Yet, the high relapse rates observed in our analyses emphasize the need for novel therapeutic strategies in this clinical setting. [ABSTRACT FROM AUTHOR]

Acute graft-versus-host disease (GVHD) can affect the central nervous system (CNS). The role of microglia in CNS-GVHD remains undefined. In agreement with microglia activation, we found that profound morphological changes and MHC-II and CD80 upregulation occurred upon GVHD induction. RNA sequencing-based analysis of purified microglia obtained from mice with CNS-GVHD revealed TNF upregulation. Selective TNF gene deletion in microglia of Cx3cr1creER Tnffl/- mice reduced MHC-II expression and decreased CNS T cell infiltrates and VCAM-1+ endothelial cells. GVHD increased microglia TGF-β-activated kinase-1 (TAK1) activation and NF-κB/p38 MAPK signaling. Selective Tak1 deletion in microglia using Cx3cr1creER Tak1fl/fl mice resulted in reduced TNF production and microglial MHC-II and improved neurocognitive activity. Pharmacological TAK1 inhibition reduced TNF production and MHC-II expression by microglia, Th1 and Th17 T cell infiltrates, and VCAM-1+ endothelial cells and improved neurocognitive activity, without blocking graft-versus-leukemia effects. Consistent with these findings in mice, we observed increased activation and TNF production of microglia in the CNS of GVHD patients. In summary, we prove a role for microglia in CNS-GVHD, identify the TAK1/TNF/MHC-II axis as a mediator of CNS-GVHD, and provide a TAK1 inhibitor-based approach against GVHD-induced neurotoxicity. [ABSTRACT FROM AUTHOR]

Introduction Recurrent disease is the major cause of treatment failure after allogeneic stem cell transplantation (SCT) in patients with AML. Second SCT (SCT2) is a valid treatment option in this setting but outcome is relatively poor. Haplo-identical (haplo) SCT is increasingly used over the last decade due to the introduction of non T-depleted methods. Prior studies have shown similar outcome when using the same or different HLA-matched donor for SCT2. However, there is relatively limited data on the use of haplo-donors in this setting. Methods and Results The study included 556 patients with AML relapsing after a first allogeneic SCT (SCT1) given in CR1 from sibling (sib, n= 294) or unrelated donor (UD, n=262) and given SCT2 during the years 2006-2016. The median age at SCT2 was 46 years (20-73). 247 patients were in CR2 (45%) and 309 had active leukemia (55%) at SCT2. The conditioning regimen for SCT1 was myeloablative (MAC, 66%) or reduced-intensity (RIC, 34%), and 41% and 59%, respectively for SCT2. Patients were divided into 3 groups based on the donor selected for SCT2; 1) same donor (n=163, sib/sib-112, UD/UD-51), 2) different matched donor (n=305, sib/different sib-44, sib/UD-93, UD/ different UD- 168), 3) haplo-donor (n=88, sib/haplo-45, UD/haplo-43). All haploSCT were non T-depleted. The 2-year leukemia-free survival (LFS) after SCT2 was 23.5%, 23.7% and 21.8%, respectively (unadjusted P=0.30). Multivariate analysis showed no effect of second donor type on subsequent relapse, hazard ratio (HR) 0.96 (P=0.83) and 1.20 (P=0.47) for different donor and haplo-donor compared to same donor, respectively. UD in SCT1, CR2 at SCT2 and chronic GVHD after SCT1 were associated with reduced relapse risk after SCT2, HR 0.70 (P=0.02), 0.60 (P=0.001) and 0.66 (P=0.03), respectively. Second donor type did predict for non-relapse mortality (NRM) after SCT2; HR 1.26 (P=0.41) and 2.18 (P=0.02) for different donor and haplo-donor compared to same donor, respectively. Advanced age and MAC in SCT1 also predicted for NRM, HR 1.40 (P<0.001) and 0.61 (P=0.04), respectively. The second donor predicted for LFS after SCT2; HR 1.05 (P=0.77) and 1.55 (P=0.03), respectively. Advanced age and SCT2 in CR2 predicted for LFS; HR 1.11 (P=0.06) and 0.66 (P=0.002), respectively. In all, there were no differences between same or different matched donors in SCT2 outcomes, but haploSCT2 was associated with higher NRM and lower LFS. The inferior outcome after SCT2 with haplo-donor was limited to patients given MAC in SCT1 and not observed in patients given RIC in SCT1. Conclusions Second SCT with the same donor or different matched donor is associated with similar outcomes in patients with relapsed AML after a first SCT. However, SCT2 with a haplo-donor is associated with higher NRM and lower LFS, mostly in patients given MAC in SCT1. Second haplo donor does not provide better GVL effect in this setting. [ABSTRACT FROM AUTHOR]

Highlights • Overall survival, progression-free survival, and nonrelapse mortality were better in haploidentical than in cord blood donors. • Nonrelapse mortality was not significantly different between haploidentical and mismatched unrelated donor. • Relapse risk was not influenced by the type of donor. • Acute graft-versus-host disease risk was lower with haploidentical or cord blood donors than with mismatched unrelated donors. • Chronic graft-versus-host disease was not influenced by the type of donor. Abstract Recently, haploidentical transplantation (haplo) using post-transplant cyclophosphamide (PTCy) has been reported to give very encouraging results in patients with hematological malignancies. Patients who have no HLA-matched donor currently have the choice between a mismatched unrelated donor, an unrelated cord blood (CB) donor, and a haploidentical related donor. The aim of our study is to compare the outcome of patients with myelodysplastic syndrome (MDS) who have been transplanted from a haploidentical donor using PTCy, an HLA-mismatched unrelated donor (marrow or peripheral blood stem cells), or an unrelated mismatched CB donor. A total of 833 MDS patients from the European Group for Blood and Marrow Transplantation (EBMT) registry, transplanted between 2011 and 2016, were identified. The potential benefit of haplo was compared with mismatched unrelated and CB donors in an adjusted and weighted model taking into account potential confounders and other prognostic variables. Haplo was at lower risk of acute graft-versus-host disease (GVHD) than mismatched unrelated donor (P =.010) but at similar risk than CB. Progression-free survival was better after haplo (versus mismatched unrelated, P =.056; versus CB, P =.003) and overall survival tended to be superior after haplo (versus mismatched unrelated, P =.082; versus CB, P =.002). Nonrelapse mortality was not significantly different between haplo and mismatched unrelated donors. Relapse risk was not influenced by the type of donor. In conclusion, patients with MDS from the EBMT registry receiving hematopoietic stem cell transplantation from a haplo donor have significantly better outcome than those receiving hematopoietic stem cell transplantation from a CB donor and at least similar or better outcome than with a mismatched unrelated donor. Prospective studies comparing the type of donors will be needed to confirm this assumption. [ABSTRACT FROM AUTHOR]

Highlights • Incidence of BOS after reduced-intensity conditioning. • Mild small airway disease before transplantation predicts bronchiolitis obliterans. • Pulmonary cause of death is linked to pretransplantation severe small airway disease. • Mixed lung disease after transplantation is associated with non-relapse mortality Abstract Lung function deterioration contributes to treatment-related morbidity and mortality in patients after allogeneic hematopoietic cell transplantation (allo-HCT). Better understanding of impaired lung function including bronchiolitis obliterans syndrome (BOS) as chronic manifestation of graft-versus-host disease (GVHD) might improve outcomes of patients after allo-HCT. To detect early pulmonary function test abnormalities associated with BOS incidence and outcome after allo-HCT, we performed a retrospective analysis of homogenous-treated 445 patients (median age, 61.9 years; range, 19 to 76 years) with a reduced intensity/toxicity conditioning protocol. The cumulative incidence of BOS was 4.1% (95% confidence interval [CI], 2.6 to 6.4) at 1 year and 8.6% (95% CI, 6.3 to 11.6) at 5 years after allo-HCT with a median follow-up of 43.2 months (range, 3.3 to 209 months). In multivariate analysis, pre-existence of moderate small airway disease reflected by decreased midexpiratory flows before allo-HCT was associated with increased risk for BOS development. In addition, severe small airway disease before allo-HCT and combined restrictive/obstructive lung disease at day +100 after allo-HCT were associated with higher risk for nonrelapse mortality (NRM) due mainly to pulmonary cause of death. In summary, we identified novel pulmonary function test abnormalities prior and after allo-HCT associated with BOS development and NRM. These findings might help to identify a risk population and result in personalized GVHD prophylaxis and preventive or early therapeutic interventions. [ABSTRACT FROM AUTHOR]

Background: Chronic graft-versus-host disease (GVHD) is the leading cause of later illness and death after allogeneic hematopoietic stem-cell transplantation. We hypothesized that the inclusion of antihuman T-lymphocyte immune globulin (ATG) in a myeloablative conditioning regimen for patients with acute leukemia would result in a significant reduction in chronic GVHD 2 years after allogeneic peripheral-blood stem-cell transplantation from an HLA-identical sibling.Methods: We conducted a prospective, multicenter, open-label, randomized phase 3 study of ATG as part of a conditioning regimen. A total of 168 patients were enrolled at 27 centers. Patients were randomly assigned in a 1:1 ratio to receive ATG or not receive ATG, with stratification according to center and risk of disease.Results: After a median follow-up of 24 months, the cumulative incidence of chronic GVHD was 32.2% (95% confidence interval [CI], 22.1 to 46.7) in the ATG group and 68.7% (95% CI, 58.4 to 80.7) in the non-ATG group (P<0.001). The rate of 2-year relapse-free survival was similar in the ATG group and the non-ATG group (59.4% [95% CI, 47.8 to 69.2] and 64.6% [95% CI, 50.9 to 75.3], respectively; P=0.21), as was the rate of overall survival (74.1% [95% CI, 62.7 to 82.5] and 77.9% [95% CI, 66.1 to 86.1], respectively; P=0.46). There were no significant between-group differences in the rates of relapse, infectious complications, acute GVHD, or adverse events. The rate of a composite end point of chronic GVHD-free and relapse-free survival at 2 years was significantly higher in the ATG group than in the non-ATG group (36.6% vs. 16.8%, P=0.005).Conclusions: The inclusion of ATG resulted in a significantly lower rate of chronic GVHD after allogeneic transplantation than the rate without ATG. The survival rate was similar in the two groups, but the rate of a composite end point of chronic GVHD-free survival and relapse-free survival was higher with ATG. (Funded by the Neovii Biotech and the European Society for Blood and Marrow Transplantation; ClinicalTrials.gov number, NCT00678275.). [ABSTRACT FROM AUTHOR]

Hematopoietic stem cell transplantation (HSCT) remains the only curative treatment in patients with higher risk myelodysplastic syndrome (MDS), but the choice of the optimal alternative stem cell source is still a subject of debate in patients lacking an HLA-matched sibling donor. Here, we report on a large series of patients with MDS (N = 631) transplanted either with mobilized peripheral stem cells (PBs) from unrelated donors (n = 502) or with umbilical cord blood transplant (UCB, n = 129) as alternative grafts after reduced-intensity conditioning. Neutrophil engraftment was higher after PB (98% versus 78%, P < .0001). Acute graft-versus-host disease (GVHD) was similar after PB (31%) and UCB (29%), and chronic GVHD incidence was higher after PB (41% versus 23%). Two-year nonrelapse mortality was lower after PB (31% versus 42% P = .03). There was a better overall survival (OS) and disease-free survival (DFS) after PB (49% ± 2% versus 30% ± 4%, P < .0001 and 44% ± 2% versus 28% ± 4%, P < .0001). Multivariate analysis confirmed the advantage of PB for treatment-related mortality, OS, and DFS, whereas relative risk of chronic GVHD was similar. A multivariate analysis comparing PB from a 10/10 HLA-matched donor, PB from a 9/10 HLA-matched donor, and UCB showed an advantage on treatment-related mortality, DFS, and OS only in 10/10 PB. We conclude that in MDS patients lacking an HLA-matched sibling donor, PB from a 10/10 HLA-matched unrelated donor is the preferred source of hematopoietic stem cells. HLA-mismatched unrelated donor or cord blood seem to give similar inferior results except for neutrophil engraftment, which is delayed after UCB. [ABSTRACT FROM AUTHOR]

Acute graft-versus-host disease (GVHD) limits the success of allogeneic hematopoietic cell transplantation (allo-HCT); therefore, a better understanding of its biology may improve therapeutic options. We observed miR-146a up-regulation in T cells of mice developing acute GVHD compared with untreated mice. Transplanting miR-146a-/- T cells caused increased GVHD severity, elevated tumor necrosis factor (TNF) serum levels, and reduced survival. TNF receptor-associated factor 6 (TRAF6), a verified target of miR-146a, was up-regulated in miR-146a-/- T cells following alloantigen stimulation. Higher TRAF6 levels translated into increased nuclear factor-κB activity and TNF production in miR-146a-/- T cells. Conversely, the detrimental effect of miR-146a deficiency in T cells was antagonized by TNF blockade, whereas phytochemical induction of miR-146a or its overexpression using a miR-146a mimic reduced GVHD severity. In humans, the minor genotype of the single nucleotide polymorphism rs2910164 in HCT donors, which reduces expression of miR-146a, was associated with severe acute GVHD (grade III/IV). We show that miR-146a functions as a negative regulator of donor T cells in GVHD by targeting TRAF6, leading to reduced TNF transcription. Because miR-146a expression can be exogenously enhanced, our results provide a novel targeted molecular approach to mitigate GVHD. [ABSTRACT FROM AUTHOR]

Graft-versus-host-disease (GVHD) is a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT) characterized by the production of high levels of proinflammatory cytokines. Activated Janus kinases (JAKs) are required for T-effector cell responses in different inflammatory diseases, and their blockade could potently reduce acute GVHD. We observed that inhibition of JAK1/2 signaling resulted in reduced proliferation of effector T cells and suppression of proinflammatory cytokine production in response to alloantigen in mice. In vivo JAK 1/2 inhibition improved survival of mice developing acute GVHD and reduced histopathological GVHD grading, serum levels of proinflammatory cytokines, and expansion of alloreactive luc-transgenic T cells. Mechanistically, we could show that ruxolitinib impaired differentiation of CD4+ T cells into IFN-γ-and IL17A-producing cells, and that both T-cell phenotypes are linked to GVHD. Conversely, ruxolitinib treatment in allo-HCT recipients increased Fox P3+ regulatory T cells, which are linked to immunologic tolerance. Based on these results, we treated 6 patients with steroid-refractory GVHD with ruxolitinib. All patients responded with respect to clinical GVHD symptoms and serum levels of proinflammatory cytokines. In summary, ruxolitinib represents a novel targeted approach in GVHD by suppression of proinflammatory signaling that mediates tissue damage and by promotion of tolerogenic Treg cells. [ABSTRACT FROM AUTHOR]

Acute graft-versus-host disease (GvHD) is a complex process involving endothelial damage and neovascularization. Better understanding of the pathophysiology of neovascularization during GvHD could help to target this process while leaving T-cell function intact. Under ischemic conditions, neovascularization is regulated by different micro RNAs (miRs), which potentially play a role in inflamed hypoxic GvHD target organs. We observed strong neovascularization in the murine inflamed intestinal tract (IT) during GvHD. Positron emission tomography imaging demonstrated abundant αvβ3 integrin expression within intestinal neovascularization areas. To interfere with neovascularization, we targeted αv integrin-expressing endothelial cells, which blocked their accumulation in the IT and reduced GvHD severity independent of immune re-constitution and graft-versus-tumor effects. Additionally, enhanced neovascularization and αv integrin expression correlated with GvHD severity in humans. Expression analysis of miRs in the inflamed IT of mice developing GvHD identified miR-100 as significantly downregulated. Inactivation of miR-100 enhanced GvHD indicating a protective role for miR-100 via blocking inflammatory neovascularization. Our data from the mouse model and patients indicate that inflammatory neovascularization is a central event during intestinal GvHD that can be inhibited by targeting αv integrin. We identify negative regulation of GvHD-related neovascularization by miR-1 00, which indicates common pathomechanistic features of GvHD and ischemia. [ABSTRACT FROM AUTHOR]

Toxicity-reduced conditioning is a curative treatment option for medically compromised or elderly patients ineligible for myeloablative hematopoietic cell transplantation (HCT). The aim of this study was to detect prognostic factors for overall survival (OS) and to evaluate quality of life (QOL) in a large homogeneous cohort of 160 consecutive patients aged ≥60 years treated with allogeneic HCT. We evaluated age, sex, performance status, comorbidities, pulmonary function, lactic dehydrogenase concentration, type of donor, disease status, CD34+ cells transplanted, cytomegalovirus status, time from diagnosis to HCT, and the development of acute and chronic graft-versus-host disease (GVHD). All patients who survived for ≥6 months (n = 79) were asked to complete a QOL survey. All patients (median age, 64.7 years; range, 60.1-76 years) received pretransplantation conditioning with fludarabine, BCNU, and melphalan. With a median follow-up of 35 months, the 1-year OS was 62.4% and 3-year OS was 47.4%. Multivariate analysis revealed compromised performance status as the most significant negative prognostic parameter for OS (P < .003), whereas male donor (P = .008) and chronic GVHD (P = .024) were associated with better OS. The 89% of survivors who returned the QOL questionnaire rated their global QOL as good-to-excellent despite impaired functional capabilities and such symptoms as fatigue, dyspnea, and loss of appetite. The main prognostic factor was performance status, not age. Our data suggest that toxicity-reduced conditioning offers a chance for enhanced OS with an adequate QOL. [Copyright &y& Elsevier]

Prophylaxis of acute graft-versus-host disease (aGVHD), while maintaining the graft-versus-leukemia (GVL)/lymphoma effect and preventing severe infectious diseases, remains the main challenge in allogeneic hematopoetic cell transplantation (allo-HCT). To evaluate this, we examined the feasibility of deescalating the dose of alemtuzumab (MabCampath™) in combination with cyclosporine (CsA) as the sole GVHD-prophylaxis in patients after fludarabine (Flu)-based reduced-intensity conditioning (RIC) in an observational cohort study. We included 127 consecutive patients (median age 63 years) with an unrelated (UD; n=69) or related donor (SIB; n=58) after their first transplantation, mostly presenting with advanced disease. The first 30 patients received 20 mg/day on day −2 and −1 (40 mg), the following 48 patients 10 mg/day on day −2 and −1 (20 mg), and the last 49 patients 10 mg on day −1 (10 mg) alemtuzumab intravenous (i.v.) prior to transplant. We observed no statistical differences comparing the 40 mg, 20 mg, or 10 mg dose groups, in terms of cumulative incidences of aGVHD grade III-IV 7% (confidence interval [CI] 95%; 1-51), 12% (1-40), 6% (1-40), extensive chronic GVHD (cGVHD) 24.4% (3.3-55.8), 17% (2.5-42), and 14.2% (1.5-41.5) and of aGVHD grade II-IV 7 % (0-51.5), 29% (11.9-49.1), 21% (15.3-43.1), respectively. The difference between the 20-mg and 40-mg groups was significant for aGVHD grade II-IV(P < .05). In conclusion, we demonstrate the feasibility of reducing the dose of alemtuzumab as GVHD-prophylaxis to 10 mg absolute in combination with CsA only for UD transplantation in particular. [Copyright &y& Elsevier]

Abstract: Development of severe steroid-resistant acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT) is associated with poor outcome. The humanized monoclonal antibody alemtuzumab was shown to be effective in GVHD prophylaxis in conditioning regimens before allogeneic HCT. We evaluated the efficacy and safety of alemtuzumab in 20 patients with histologically confirmed steroid refractory grade III and IV intestinal GVHD after related and unrelated HCT. Overall response rate was 70%, with complete response in 35%. Despite the severe grade of GVHD in our patients, the median survival of 280 days and 1-year overall survival (OS) of 50% were superior or comparable to those associated with other treatment options. Cytomegalovirus (CMV) reactivation, bacterial infection, and invasive aspergillosis were frequent complications; however, infection was not a significant predictor for survival. These data suggest that treatment with alemtuzumab has favorable activity in severe intestinal GVHD after allogeneic HCT, but emphasize the importance of careful monitoring and anti-infectious supportive care. [Copyright &y& Elsevier]

Molecular pathogenesis of relapse after allogeneic hematopoietic cell transplantation is poorly understood. Data regarding relapse mechanisms after transplantation is scarcely available. We investigated genomic aberrations (GAs) in 21 patients undergoing related and unrelated HLA-matched transplantation in leukemic blasts before transplant and at relapse after transplantation. We found a higher number of GAs after transplantation, suggesting increased genomic instability during relapse. Two of 21 patients showed a large homozygous region spanning the whole HLA-locus on chromosome 6p in the relapse sample. In both patients sequence-based HLA typing of the blasts revealed a loss of the patient-specific allele at the mismatched locus leading to homozygosity for the HLA haplotype shared by the patient and the donor. In addition, GAs were found in critical regions such as 12p13, 13q12.2, and 17p13. Our results suggest that escape from immunologic surveillance may be a relevant mechanism of relapse after transplantation in patients with GAs on chromosome 6p. A combination of continuous immunologic pressure mediated by donor T cells and clonal evolution of myeloid leukemia may result in acquired GAs after transplantation. [Copyright &y& Elsevier]