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Steroid-refractory chronic graft-versus-host disease (cGVHD) after allogeneic transplant remains a significant cause of morbidity and mortality. Abatacept is a selective costimulation modulator, used for the treatment of rheumatologic diseases, and was recently the first drug to be approved by the US Food and Drug Administration for the prophylaxis of acute graft-versus-host disease. We conducted a phase 2 study to evaluate the efficacy of abatacept in steroid-refractory cGVHD. The overall response rate was 58%, seen in 21 out of 36 patients, with all responders achieving a partial response. Abatacept was well tolerated with few serious infectious complications. Immune correlative studies showed a decrease in interleukin -1α (IL-1α), IL-21, and tumor necrosis factor α as well as decreased programmed cell death protein 1 expression by CD4+ T cells in all patients after treatment with abatacept, demonstrating the effect of this drug on the immune microenvironment. The results demonstrate that abatacept is a promising therapeutic strategy for the treatment of cGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01954979., (© 2023 by The American Society of Hematology.)

Older patients with acute myeloid leukemia (AML) have high relapse risk and poor survival after allogeneic hematopoietic cell transplantation (HCT). Younger patients may receive myeloablative conditioning to mitigate relapse risk associated with high-risk genetics or measurable residual disease (MRD), but older adults typically receive reduced-intensity conditioning (RIC) to limit toxicity. To identify factors that drive HCT outcomes in older patients, we performed targeted mutational analysis (variant allele fraction ≥2%) on diagnostic samples from 295 patients with AML aged ≥60 years who underwent HCT in first complete remission, 91% of whom received RIC, and targeted duplex sequencing at remission in a subset comprising 192 patients. In a multivariable model for leukemia-free survival (LFS) including baseline genetic and clinical variables, we defined patients with low (3-year LFS, 85%), intermediate (55%), high (35%), and very high (7%) risk. Before HCT, 79.7% of patients had persistent baseline mutations, including 18.3% with only DNMT3A or TET2 (DT) mutations and 61.4% with other mutations (MRD positive). In univariable analysis, MRD positivity was associated with increased relapse and inferior LFS, compared with DT and MRD-negative mutations. However, in a multivariable model accounting for baseline risk, MRD positivity had no independent impact on LFS, most likely because of its significant association with diagnostic genetic characteristics, including MDS-associated gene mutations, TP53 mutations, and high-risk karyotype. In summary, molecular associations with MRD positivity and transplant outcomes in older patients with AML are driven primarily by baseline genetics, not by mutations present in remission. In this group of patients, where high-intensity conditioning carries substantial risk of toxicity, alternative approaches to mitigating MRD-associated relapse risk are needed., (© 2022 by The American Society of Hematology.)

Relapsed myeloid disease after allogeneic stem cell transplantation (HSCT) remains largely incurable. We previously demonstrated the potent activity of immune checkpoint blockade in this clinical setting with ipilimumab or nivolumab. To define the molecular and cellular pathways by which CTLA-4 blockade with ipilimumab can reinvigorate an effective graft-versus-leukemia (GVL) response, we integrated transcriptomic analysis of leukemic biopsies with immunophenotypic profiling of matched peripheral blood samples collected from patients treated with ipilimumab following HSCT on the Experimental Therapeutics Clinical Trials Network 9204 trial. Response to ipilimumab was associated with transcriptomic evidence of increased local CD8+ T-cell infiltration and activation. Systemically, ipilimumab decreased naïve and increased memory T-cell populations and increased expression of markers of T-cell activation and costimulation such as PD-1, HLA-DR, and ICOS, irrespective of response. However, responding patients were characterized by higher turnover of T-cell receptor sequences in peripheral blood and showed increased expression of proinflammatory chemokines in plasma that was further amplified by ipilimumab. Altogether, these data highlight the compositional T-cell shifts and inflammatory pathways induced by ipilimumab both locally and systemically that associate with successful GVL outcomes. This trial was registered at www.clinicaltrials.gov as #NCT01822509.

Programmed cell death-1 (PD-1)/programmed death ligand-1 blockade may potentially augment graft-vs-tumor effects following allogeneic hematopoietic cell transplantation (alloHCT), but retrospective studies of anti-PD-1 therapy reported substantial toxicity from graft-versus-host-disease (GVHD). Here, we report the results of a prospective clinical trial of PD-1 blockade for relapsed hematologic malignancies (HMs) after alloHCT (NCT01822509). The primary objective in this phase 1 multicenter, investigator-initiated study was to determine maximum tolerated dose and safety. Secondary objectives were to assess efficacy and immunologic activity. Patients with relapsed HMs following alloHCT were eligible. Nivolumab was administered every 2 weeks until progression or unacceptable toxicity, starting with a 1-mg/kg cohort, with planned deescalation based on toxicity to a 0.5-mg/kg cohort. Twenty-eight patients were treated (n = 19 myeloid, n = 9 lymphoid). Median age was 57 years (range 27-76), and median time from alloHCT to enrollment was 21 months (range 5.6-108.5). Two of 6 patients treated at 1 mg/kg experienced dose-limiting toxicity (DLT) from immune-related adverse events (irAEs). Twenty-two patients were treated at 0.5 mg/kg, and 4 DLTs occurred, including 2 irAEs and 2 with fatal GVHD. The overall response rate in efficacy-evaluable patients was 32% (8/25). With a median follow-up of 11 months, the 1-year progression-free survival and overall survival were 23% and 56%, respectively. In this first prospective clinical trial of an anti-PD-1 antibody for post-alloHCT relapse, GVHD and irAEs occurred, requiring dose deescalation, with only modest antitumor activity. Further studies of anti-PD-1 therapy post-alloHCT may require specific toxicity mitigation strategies. This trial was registered at www.clinicaltrials.gov as #NCT01822509.

To assess incidence and risk factors for skin cancer associated with allogeneic hematopoietic stem cell transplantation, we evaluated 1,974 adult allogeneic hematopoietic stem cell transplantation patients from Beth Israel Deaconess Medical Center and Dana-Farber Cancer Institute who received transplants between January 1995 and July 2013 for hematologic malignancy and survived at least 100 days. Median age was 51.1 years, and median follow-up time was 3 years. Overall, 119 patients had 221 skin cancers. The incidences of squamous cell carcinomas (incidence rate ratio = 9.8; 95% confidence interval = 7.7-12.3), basal cell carcinomas (incidence rate ratio = 2.5; 95% confidence interval = 1.9-3.2), and melanoma (standardized incidence ratio = 3.3; 95% confidence interval = 1.7-5.9) were elevated in our cohort. In multivariable models, risk factors for squamous cell carcinomas were increased age (P < 0.0001), chronic lymphocytic leukemia (P = 0.02), and chronic graft-versus-host disease (P = 0.0002). Risk factors for basal cell carcinomas were chronic lymphocytic leukemia (P = 0.003), reduced-intensity conditioning (P = 0.02), acute graft-versus-host disease (P = 0.03), and chronic graft-versus-host disease (P = 0.003). To our knowledge, previously unreported risk factors in this contemporary cohort include prior CLL for squamous cell carcinoma and basal cell carcinoma and reduced-intensity conditioning for basal cell carcinoma. This study also supports chronic graft-versus-host disease as a risk factor for nonmelanoma skin cancer, particularly squamous cell carcinoma., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: High-dose chemotherapy (HDCT) with autologous stem-cell transplantation (aSCT) has been a standard therapy for relapsed metastatic germ-cell tumors (GCTs) over the last 2 decades, but there have been many changes in practice over time with respect to stem-cell source, mobilization, and conditioning regimens. Mobilization is impaired with greater cisplatin exposure., Patients and Methods: Patients with relapsed GCT who received HDCT/aSCT at Dana-Farber Cancer Institute between 1997 and 2017 were identified. Diagnosis, first-line chemotherapy, stem-cell mobilization, HDCT, toxicity, and survival outcomes were annotated and descriptively summarized. Univariable associations of clinicopathologic features and relapse and survival were assessed. Time-to-event analyses were performed by HDCT type and duration., Results: Thirty-five eligible patients were identified. The most common regimen before HDCT was paclitaxel, ifosfamide, and cisplatin, and it resulted in a high rate of successful initial mobilization (95%). Ten patients (29%) were mobilized with filgrastim and plerixafor (CXCR4 antagonist). All plerixafor-treated patients were mobilized with sufficient cells for 2 transplants. Oxazaphosphorine (cyclophosphamide or ifosfamide)-containing (O-C) HDCT was provided between 1997 and 2008, and subsequent patients were treated with high-dose carboplatin plus etoposide (CE). O-C HDCT was associated with excessive cardiac (33%), severe liver (93%), and renal dysfunction compared to CE. Two O-C-treated patients died of drug-related lung toxicity. Fifty-one percent of the cohort experienced relapse, and 46% died., Conclusion: Plerixafor has a role in stem-cell mobilization and aSCT for relapsed GCT when cisplatin in bridging before HDCT may be problematic. O-C and CE HDCT regimens have different toxicity patterns that are clinically meaningful., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Steroid-refractory chronic graft-versus-host disease (SR-cGVHD) remains a major cause of morbidity and mortality after allogeneic stem cell transplantation. Innovative immunotherapeutic strategies are urgently needed for the treatment of SR-cGVHD. We conducted a phase 1 clinical trial to evaluate the safety, efficacy, and immune effects of abatacept, a novel immunomodulatory drug that acts as an inhibitor of T-cell activation via costimulatory blockade, in the treatment of SR-cGVHD. The study followed a 3+3 design with 2 escalating abatacept doses: 3 mg/kg and 10 mg/kg, with an expansion cohort treated at 10 mg/kg. Abatacept was well-tolerated with no dose-limiting toxicities. Of the 16 evaluable patients, 44% achieved a clinical partial response per 2005 National Institutes of Health Consensus Criteria. Importantly, abatacept resulted in a 51.3% reduction in prednisone usage in clinical responders (mean baseline, 27 vs 14 mg; P = .01). Increased PD-1 expression on circulating CD4 ( P = .009) and CD8 ( P = .007) T cells was observed in clinical responders. In summary, abatacept was safe and led to a marked improvement in National Institutes of Health cGVHD scores and a significant reduction in prednisone use. In this cohort of heavily pretreated patients, the results suggest abatacept may be a promising therapeutic agent for SR-cGVHD, and a phase 2 trial has been initiated. This trial was registered at www.clinicaltrials.gov as #NCT01954979., (© 2018 by The American Society of Hematology.)

Corticosteroid resistance after acute graft-versus-host disease (SR-aGVHD) results in high morbidity and mortality after allogeneic hematopoietic cell transplantation. Current immunosuppressive therapies for SR-aGVHD provide marginal effectiveness because of poor response or excessive toxicity, primarily from infection. α 1 -Antitrypsin (AAT), a naturally abundant serine protease inhibitor, is capable of suppressing experimental GVHD by downmodulating inflammation and increasing ratios of regulatory (T reg ) to effector T cells (T eff s). In this prospective multicenter clinical study, we sought to determine the safety and response rate of AAT administration in SR-aGVHD. Forty patients with a median age of 59 years received intravenous AAT twice weekly for 4 weeks as first-line treatment of SR-aGVHD. The primary end point was overall response rate (ORR), the proportion of patients with SR-aGVHD in complete (CR) or partial response by day 28 without addition of further immunosuppression. Treatment was well tolerated without drug-related adverse events. A significant increase in serum levels of AAT was observed after treatment. The ORR and CR rates by day 28 were 65% and 35%, respectively, and included responses in all aGVHD target organs. At day 60, responses were sustained in 73% of patients without intervening immunosuppression. Infectious mortality was 10% at 6 months and 2.5% within 30 days of last AAT infusion. Consistent with preclinical data, correlative samples showed an increase in ratio of activated T reg s to T eff s after AAT treatment. These data suggest that AAT is safe and may be potentially efficacious in treating SR-aGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01700036., (© 2018 by The American Society of Hematology.)

Chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplant reflects a complex immune response resulting in chronic damage to multiple tissues. Previous studies indicated that donor B cells and the antibodies they produce play an important role in the development of cGVHD. To understand the pathogenic role of antibodies in cGVHD, we focused our studies on posttransplant production of immunoglobulin G antibodies targeting cell surface antigens expressed in multiple cGVHD affected tissues, due to their potential functional impact on living cells in vivo. Using plate-bound cell membrane proteins as targets, we detected a significantly higher level of antibodies reactive with these membrane antigens in patients who developed cGVHD, compared with those who did not and healthy donors. Plasma-reactive antibody levels increased significantly prior to the clinical diagnosis of cGVHD and were reduced following cGVHD therapies including prednisone, interleukin-2, or extracorporeal photophoresis. Using cell-based immunoprecipitation with plasma from cGVHD patients and mass spectrometry, we identified 43 membrane proteins targeted by these antibodies. The presence of antibodies in cGVHD patients' plasma that specifically target 6 of these proteins was validated. Antibodies reactive with these 6 antigens were more frequently detected in patients with cGVHD compared with patients without cGVHD and healthy donors. These results indicate that antibodies that target membrane antigens of living cells frequently develop in cGVHD patients and further support a role for B cells and antibodies in the development of cGVHD., (© 2017 by The American Society of Hematology.)

B-cell receptor (BCR)-activated B cells contribute to pathogenesis in chronic graft-versus-host disease (cGVHD), a condition manifested by both B-cell autoreactivity and immune deficiency. We hypothesized that constitutive BCR activation precluded functional B-cell maturation in cGVHD. To address this, we examined BCR-NOTCH2 synergy because NOTCH has been shown to increase BCR responsiveness in normal mouse B cells. We conducted ex vivo activation and signaling assays of 30 primary samples from hematopoietic stem cell transplantation patients with and without cGVHD. Consistent with a molecular link between pathways, we found that BCR-NOTCH activation significantly increased the proximal BCR adapter protein BLNK. BCR-NOTCH activation also enabled persistent NOTCH2 surface expression, suggesting a positive feedback loop. Specific NOTCH2 blockade eliminated NOTCH-BCR activation and significantly altered NOTCH downstream targets and B-cell maturation/effector molecules. Examination of the molecular underpinnings of this "NOTCH2-BCR axis" in cGVHD revealed imbalanced expression of the transcription factors IRF4 and IRF8 , each critical to B-cell differentiation and fate. All- trans retinoic acid (ATRA) increased IRF4 expression, restored the IRF4 -to- IRF8 ratio, abrogated BCR-NOTCH hyperactivation, and reduced NOTCH2 expression in cGVHD B cells without compromising viability. ATRA-treated cGVHD B cells had elevated TLR9 and PAX5 , but not BLIMP1 (a gene-expression pattern associated with mature follicular B cells) and also attained increased cytosine guanine dinucleotide responsiveness. Together, we reveal a mechanistic link between NOTCH2 activation and robust BCR responses to otherwise suboptimal amounts of surrogate antigen. Our findings suggest that peripheral B cells in cGVHD patients can be pharmacologically directed from hyperactivation toward maturity.

Objectives: The aim of this study was to evaluate the impact of oral health status on bacteremia risk in a cohort of patients with acute myeloid leukemia (AML) who underwent chemotherapy followed by myeloablative allogeneic hematopoietic cell transplantation (allo-HCT)., Study Design: A retrospective study was conducted in patients with AML from 2007 to 2011. Oral health status was determined from a pre-allo-HCT dental evaluation. Positive blood cultures were recorded from AML induction to post-allo-HCT day +60. Organisms that caused bacteremia were classified as "of possible oral source" by a blinded microbiologist. Two-sided Fisher's exact test was used to compare the oral health status of the entire cohort with that of patients with blood cultures of potential oral source., Results: Pre-allo-HCT dental evaluations were completed in 91 (99%) of 92 patients. Of these 91 patients, 13 (14%) with dental pathology (13 of 13 [100%]) completed all required dental treatment before allo-HCT. Bacteremias occurred in 63 of 92 patients (68%), and 12 (19%) of 63 patients had positive blood cultures of potential oral source. Of these, 1 of 12 patients developed bacteremia during AML induction, and 11 of 12 developed bacteremia during allo-HCT., Conclusions: Oral health status was not associated with risk of bacteremia of potential oral source either at AML induction or consolidation or at allo-HCT., (Copyright © 2017 Elsevier Inc. All rights reserved.)

CD4 + Foxp3 + regulatory T cells (Tregs) play a central role in the maintenance of immune tolerance after hematopoietic stem cell transplantation. We previously reported that low-dose interleukin-2 (IL-2) therapy increased circulating Tregs and improved clinical symptoms of chronic graft-versus-host-disease (cGVHD); however, the mechanisms that regulate Treg homeostasis during IL-2 therapy have not been well studied. To elucidate these regulatory mechanisms, we examined the role of inhibitory coreceptors on Tregs during IL-2 therapy in a murine model and in patients with cGVHD. Murine studies demonstrated that low-dose IL-2 selectively increased Tregs and simultaneously enhanced the expression of programmed cell death 1 (PD-1), especially on CD44 + CD62L + central-memory Tregs, whereas expression of other inhibitory molecules, including CTLA-4, LAG-3, and TIM-3 remained stable. PD-1-deficient Tregs showed rapid Stat5 phosphorylation and proliferation soon after IL-2 initiation, but thereafter Tregs became proapoptotic with higher Fas and lower Bcl-2 expression. As a result, the positive impact of IL-2 on Tregs was completely abolished, and Treg levels returned to baseline despite continued IL-2 administration. We also examined circulating Tregs from patients with cGVHD who were receiving low-dose IL-2 and found that IL-2-induced Treg proliferation was promptly followed by increased PD-1 expression on central-memory Tregs. Notably, clinical improvement of GVHD was associated with increased levels of PD-1 on Tregs, suggesting that the PD-1 pathway supports Treg-mediated tolerance. These studies indicate that PD-1 is a critical homeostatic regulator for Tregs by modulating proliferation and apoptosis during IL-2 therapy. Our findings will facilitate the development of therapeutic strategies that modulate Treg homeostasis to promote immune tolerance., (© 2017 by The American Society of Hematology.)

Anti-programmed cell death protein 1 (PD-1) monoclonal antibodies are being increasingly tested in patients with advanced lymphoma. Following treatment, many of those patients are likely to be candidates for allogeneic hematopoietic stem cell transplant (HSCT). However, the safety and efficacy of HSCT may be affected by prior PD-1 blockade. We conducted an international retrospective analysis of 39 patients with lymphoma who received prior treatment with a PD-1 inhibitor, at a median time of 62 days (7-260) before HSCT. After a median follow-up of 12 months, the 1-year cumulative incidences of grade 2-4 and grade 3-4 acute graft-versus-host disease (GVHD) were 44% and 23%, respectively, whereas the 1-year incidence of chronic GVHD was 41%. There were 4 treatment-related deaths (1 from hepatic sinusoidal obstruction syndrome, 3 from early acute GVHD). In addition, 7 patients developed a noninfectious febrile syndrome shortly after transplant requiring prolonged courses of steroids. One-year overall and progression-free survival rates were 89% (95% confidence interval [CI], 74-96) and 76% (95% CI, 56-87), respectively. One-year cumulative incidences of relapse and nonrelapse mortality were 14% (95% CI, 4-29) and 11% (95% CI, 3-23), respectively. Circulating lymphocyte subsets were analyzed in 17 patients. Compared with controls, patients previously treated with PD-1 blockade had significantly decreased PD-1 + T cells and decreased ratios of T-regulatory cells to conventional CD4 and CD8 T cells. In conclusion, HSCT after PD-1 blockade appears feasible with a low rate of relapse. However, there may be an increased risk of early immune toxicity, which could reflect long-lasting immune alterations triggered by prior PD-1 blockade., (© 2017 by The American Society of Hematology.)

Background Aims: Despite widespread use of umbilical cord blood (UCB) transplantation and distinct practice preferences displayed by individual UCB banks and transplant centers, little information exists on how processing variations affect patient outcomes., Methods: We reviewed 133 adult double UCB transplants performed at a single center: 98 after reduced-intensity and 35 after myeloablative conditioning. Processing associated with contributing UCB banks and units was surveyed to identify differences in practice. We analyzed effect of selected variables on clinical outcomes of engraftment, dominance, transplant-related mortality, and survival., Results: Eighty-eight percent of banks queried currently practice red blood cell (RBC) depletion before cryopreservation. This reflects a shift in practice because previously 65% of banks employed RBC-replete processing methods (i.e., cryopreservation or plasma/volume reduction). Neither neutrophil nor platelet engraftment was affected by processing conditions analyzed. RBC depletion was not associated with clinical outcomes, except in 17 recipients of 2 RBC-replete units, where survival was better than that observed in 116 recipients of ≥1 RBC-depleted units (hazard ratio 3.26, P = 0.004). When analyzed by attributes of the dominant unit, RBC depletion, time in storage, bank years in existence, and inventory size did not affect clinical outcomes. Postthaw viability and CD34 dose were factors impacting engraftment. Notably, all RBC-replete units in this cohort were washed in dextran-human serum albumin before infusion., Discussion: These findings support continued utilization of the entire existing pool of cord blood units, despite recent trends in processing, and have important implications for banking resources and UCB selection practices., (Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

The oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) is frequently activated inappropriately in a wide range of hematological and solid cancers, but clinically available therapies targeting STAT3 are lacking. Using a computational strategy to identify compounds opposing the gene expression signature of STAT3, we discovered atovaquone (Mepron), an antimicrobial approved by the US Food and Drug Administration, to be a potent STAT3 inhibitor. We show that, at drug concentrations routinely achieved clinically in human plasma, atovaquone inhibits STAT3 phosphorylation, the expression of STAT3 target genes, and the viability of STAT3-dependent hematological cancer cells. These effects were also observed with atovaquone treatment of primary blasts isolated from patients with acute myelogenous leukemia or acute lymphocytic leukemia. Atovaquone is not a kinase inhibitor but instead rapidly and specifically downregulates cell-surface expression of glycoprotein 130, which is required for STAT3 activation in multiple contexts. The administration of oral atovaquone to mice inhibited tumor growth and prolonged survival in a murine model of multiple myeloma. Finally, in patients with acute myelogenous leukemia treated with hematopoietic stem cell transplantation, extended use of atovaquone for Pneumocystis prophylaxis was associated with improved relapse-free survival. These findings establish atovaquone as a novel, clinically accessible STAT3 inhibitor with evidence of anticancer efficacy in both animal models and humans., (© 2016 by The American Society of Hematology.)

Chronic graft-versus-host disease (cGVHD) is associated with inadequate reconstitution of tolerogenic CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs). Previous phase 1 studies identified a low daily dose of interleukin-2 (IL-2) that was well tolerated, did not exacerbate alloimmunity, augmented Treg in vivo, and was associated with improvement of active cGVHD. In the current phase 2 study, 35 adults with steroid-refractory cGVHD received daily IL-2 (1 × 10(6) IU/m(2)) for 12 weeks. Median time from transplantation and cGVHD onset was 616 days (range, 270-2145 days) and 317 days (range, 28-1880 days), respectively. Two patients withdrew and 5 required IL-2 dose reductions due to side effects. Twenty of 33 evaluable patients (61%) had clinical responses at multiple cGVHD sites (liver, skin, gastrointestinal tract, lung, joint/muscle/fascia). Three patients (9%) had progressive cGVHD. Compared with pretreatment levels, Treg and natural killer cell counts rose >fivefold (P < .001) and >fourfold (P < .001), respectively, without significant change in conventional CD4 T cells (Tcons) or CD8 T cells. The Treg:Tcon ratio rose >fivefold (P < .001). Clinical responders initiated IL-2 earlier (508 vs 917 days after transplantation, P = .005; 249 vs 461 days after cGVHD onset; P = .03). Treg:Tcon ratios ≥0.07 at baseline and ≥0.2 at week 1 also predicted clinical response (P = .003; P = .0003, respectively). After a 4-week treatment hiatus, clinical responders were eligible to continue IL-2 therapy indefinitely. During 2 years of extended IL-2 therapy, clinical and Treg immune responses persisted, while Tcon count and Treg:Tcon ratio gradually normalized. Low-dose IL-2 provides durable clinical improvement in active cGVHD and extended therapy is well-tolerated., (© 2016 by The American Society of Hematology.)

Chronic graft-versus-host disease (cGVHD) remains a major late complication of allogeneic hematopoietic stem cell transplantation (HSCT). Previous studies have established that both donor B and T cells contribute to immune pathology in cGVHD but the mechanisms responsible for coordinated B- and T-cell responses directed against recipient antigens have not been understood. T follicular helper cells (TFH) play an important role in the regulation of B-cell immunity. We performed extensive phenotypic and functional analysis of circulating TFH (cTFH) and B cells in 66 patients after HSCT. Patients with active cGVHD had a significantly lower frequency of cTFH compared with patients without cGVHD. This was associated with higher CXCL13 plasma levels suggesting increased homing of TFH to secondary lymphoid organs. In patients with active cGVHD, cTFH phenotype was skewed toward a highly activated profile with predominance of T helper 2 (Th2)/Th17 subsets. Activated cTFH in patients with cGVHD demonstrated increased functional ability to promote B-cell immunoglobulin secretion and maturation. Moreover, the activation signature of cTFH was highly correlated with increased B-cell activation and plasmablast maturation in patients after transplant. These studies provide new insights into the immune pathogenesis of human cGVHD and identify TFH as a key coordinating element supporting B-cell involvement in this disease., (© 2016 by The American Society of Hematology.)

The development and maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT) requires the balanced reconstitution of donor-derived CD4 regulatory T cells (CD4Tregs) as well as effector CD4 (conventional CD4 T cells [CD4Tcons]) and CD8 T cells. To characterize the complex mechanisms that lead to unbalanced recovery of these distinct T-cell populations, we studied 107 adult patients who received T-replete stem cell grafts after reduced-intensity conditioning. Immune reconstitution of CD4Treg, CD4Tcon, and CD8 T cells was monitored for a 2-year period. CD3 T-cell counts gradually recovered to normal levels during this period but CD8 T cells recovered more rapidly than either CD4Tregs or CD4Tcons. Reconstituting CD4Tregs and CD4Tcons were predominantly central memory (CM) and effector memory (EM) cells and CD8 T cells were predominantly terminal EM cells. Thymic generation of naive CD4Tcon and CD8 T cells was maintained but thymic production of CD4Tregs was markedly decreased with little recovery during the 2-year study. T-cell proliferation was skewed in favor of CM and EM CD4Tcon and CD8 T cells, especially 6 to 12 months after HSCT. Intracellular expression of BCL2 was increased in CD4Tcon and CD8 T cells in the first 3 to 6 months after HSCT. Early recovery of naive and CM fractions within each T-cell population 3 months after transplant was also strongly correlated with the subsequent development of chronic graft-versus-host disease (GVHD). These dynamic imbalances favor the production, expansion, and persistence of effector T cells over CD4Tregs and were associated with the development of chronic GVHD., (© 2016 by The American Society of Hematology.)

Corticosteroids are the accepted primary therapy for acute graft-versus-host disease (GVHD), but durable responses are seen in only about half of the patients. Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0802, a phase 3 multicenter randomized double-blinded trial, was designed to test whether mycophenolate mofetil (MMF) plus corticosteroids was superior to corticosteroids alone as initial therapy for acute GVHD. Patients with newly diagnosed acute GVHD were eligible if they required systemic therapy. Patients were randomized to receive prednisone with either MMF or placebo. The primary end point was acute or chronic GVHD-free survival at day 56 after initiation of therapy. A futility rule for GVHD-free survival at day 56 was met at a planned interim analysis after 235 patients (of 372) were enrolled: 116 MMF, 119 placebo. Baseline characteristics were well balanced between treatment groups including grade and organ distribution of GVHD. GVHD-free survival at day 56, cumulative incidence of chronic GVHD at 12 months, overall survival, Epstein-Barr virus reactivation, severe, life-threatening infections, relapse at 12 months, and quality of life were similar. The addition of MMF to corticosteroids as initial therapy for acute GVHD does not improve GVHD-free survival compared with corticosteroids alone. This trial was registered at www.clinicaltrials.gov as #NCT01002742., (© 2014 by The American Society of Hematology.)

The rising incidence of pediatric obesity may significantly affect bone marrow transplantation (BMT) outcomes. We analyzed outcomes in 3687 children worldwide who received cyclophosphamide-based BMT regimens for leukemias between 1990 and 2007. Recipients were classified according to age-adjusted body mass index (BMI) percentiles as underweight (UW), at risk of UW (RUW), normal, overweight (OW), or obese (OB). Median age and race were similar in all groups. Sixty-one percent of OB children were from the United States/Canada. Three-year relapse-free and overall survival ranged from 48% to 52% (P = .54) and 55% to 58% (P = .81) across BMI groups. Three-year leukemia relapses were 33%, 33%, 29%, 25%, and 21% in the UW, RUW, normal, OW, and OB groups, respectively (P < .001). Corresponding cumulative incidences for transplant-related mortality (TRM) were 18%, 19%, 21%, 22%, and 28% (P < .01). Multivariate analysis demonstrated a decreased risk of relapse compared with normal BMI (relative risk [RR] = 0.73; P < .01) and a trend toward higher TRM (RR = 1.28; P = .014). BMI in children is not significantly associated with different survival after BMT for hematologic malignancies. Obese children experience less relapse posttransplant compared with children with normal BMI; however, this benefit is offset by excess in TRM., (© 2014 by The American Society of Hematology.)

We conducted a prospective cohort study testing the noninferiority of survival of ablative intravenous busulfan (IV-BU) vs ablative total body irradiation (TBI)-based regimens in myeloid malignancies. A total of 1483 patients undergoing transplantation for myeloid malignancies (IV-BU, N = 1025; TBI, N = 458) were enrolled. Cohorts were similar with respect to age, gender, race, performance score, disease, and disease stage at transplantation. Most patients had acute myeloid leukemia (68% IV-BU, 78% TBI). Grafts were primarily peripheral blood (77%) from HLA-matched siblings (40%) or well-matched unrelated donors (48%). Two-year probabilities of survival (95% confidence interval [CI]), were 56% (95% CI, 53%-60%) and 48% (95% CI, 43%-54%, P = .019) for IV-BU (relative risk, 0.82; 95% CI, 0.68-0.98, P = .03) and TBI, respectively. Corresponding incidences of transplant-related mortality (TRM) were 18% (95% CI, 16%-21%) and 19% (95% CI, 15%-23%, P = .75) and disease progression were 34% (95% CI, 31%-37%) and 39% (95% CI, 34%-44%, P = .08). The incidence of hepatic veno-occlusive disease (VOD) was 5% for IV-BU and 1% with TBI (P < .001). There were no differences in progression-free survival and graft-versus-host disease. Compared with TBI, IV-BU resulted in superior survival with no increased risk for relapse or TRM. These results support the use of myeloablative IV-BU vs TBI-based conditioning regimens for treatment of myeloid malignancies.

Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells (HSCs) for use in allogeneic transplantation. Key advantages of UCB are rapid availability and less stringent requirements for HLA matching. However, UCB contains an inherently limited HSC count, which is associated with delayed time to engraftment, high graft failure rates, and early mortality. 16,16-Dimethyl prostaglandin E2 (dmPGE2) was previously identified to be a critical regulator of HSC homeostasis, and we hypothesized that brief ex vivo modulation with dmPGE2 could improve patient outcomes by increasing the "effective dose" of HSCs. Molecular profiling approaches were used to determine the optimal ex vivo modulation conditions (temperature, time, concentration, and media) for use in the clinical setting. A phase 1 trial was performed to evaluate the safety and therapeutic potential of ex vivo modulation of a single UCB unit using dmPGE2 before reduced-intensity, double UCB transplantation. Results from this study demonstrated clear safety with durable, multilineage engraftment of dmPGE2-treated UCB units. We observed encouraging trends in efficacy, with accelerated neutrophil recovery (17.5 vs 21 days, P = .045), coupled with preferential, long-term engraftment of the dmPGE2-treated UCB unit in 10 of 12 treated participants.

B cells are implicated in the pathophysiology of chronic graft-vs-host disease (GVHD), and phase 2 trials suggest that B cell depletion can treat established chronic GVHD. We hypothesized that posttransplantation B cell depletion could prevent the occurrence of chronic GVHD. We performed a 65-patient phase 2 trial of rituximab (375 mg/m(2) IV), administered at 3, 6, 9, and 12 months after transplantation. Rituximab administration was safe without severe infusional adverse events. The cumulative incidences of chronic GVHD and systemic corticosteroid-requiring chronic GVHD at 2 years from transplantation were 48% and 31%, respectively, both lower than the corresponding rates in a concurrent control cohort (60%, P = .1, and 48.5%, P = .015). There was no difference in relapse incidence, but treatment-related mortality at 4 years from transplantation was significantly lower in treated subjects when compared with controls (5% vs 19%, P = .02), and overall survival was superior at 4 years (71% vs 56%, P = .05). At 2 years from transplantation, the B-cell activating factor/B-cell ratio was significantly higher in subjects who developed chronic GVHD in comparison with those without chronic GVHD (P = .039). Rituximab can prevent systemic corticosteroid-requiring chronic GVHD after peripheral blood stem cell transplantation and should be tested in a prospective randomized trial.

Rationale: Bronchiolitis obliterans syndrome (BOS) is a late, non-infectious pulmonary complication following hematopoietic stem cell transplantation (HSCT). There is minimal data published on quantitative radiologic characterization of airway remodeling in these subjects., Objectives: To examine quantitative measurements of airway morphology and their correlation with lung function in a cohort of patients who underwent HSCT and developed BOS., Methods: All adult patients who underwent allogeneic HSCT at the Dana-Farber Cancer Institute/Brigham and Women's Hospital (n = 1854) between January 1st 2000 and June 30th 2010 were screened for the development of BOS. Clinically acquired high resolution CT (HRCT) scans of the chest were collected. For each subjects discrete measures of airway wall area were performed and the square root of wall area of a 10-mm luminal perimeter (Pi10) was calculated., Measurements and Main Results: We identified 88 cases of BOS, and 37 of these patients had available HRCT. On CT scans obtained after BOS diagnosis, the Pi10 decreased (consistent with airway dilation) as compared with pre-BOS values (p < 0.001). After HSCT the Pi10 correlated with FEV(1)% predicted (r = 0.636, p < 0.0001), and RV/TLC% predicted (r = -0.736, p < 0.0001), even after adjusting for age, sex and total lung capacity (p < 0.0001 for both)., Conclusions: On HRCT scan BOS is characterized by central airway dilation, the degree of which is correlated to decrements in lung function. This is opposite of what has been previously demonstrated in COPD and asthma that quantitative measure of proximal airway wall thickening directly correlate with pulmonary function. Our data suggests that the pathologic process affecting the central airways is different from the pathology observed in the distal airways. Further work is needed to determine if such change can be used as a sensitive and specific tool for the future diagnosis and staging of BOS., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The outcome of allogeneic HSCT varies considerably by the disease and remission status at the time of transplantation. Any retrospective or prospective HSCT study that enrolls patients across disease types must account for this heterogeneity; yet, current methods are neither standardized nor validated. We conducted a retrospective study of 1539 patients who underwent transplantation at Dana-Farber Cancer Institute/Brigham and Women's Hospital from 2000 to 2009. Using multivariable models for overall survival, we created a disease risk index. This tool uses readily available information about disease and disease status to categorize patients into 4 risk groups with significantly different overall survival and progression-free survival on the basis of primarily differences in the relapse risk. This scheme applies regardless of conditioning intensity, is independent of comorbidity index, and was validated in an independent cohort of 672 patients from the Fred Hutchinson Cancer Research Center. This simple and validated scheme could be used to risk-stratify patients in both retrospective and prospective HSCT studies, to calibrate HSCT outcomes across studies and centers, and to promote the design of HSCT clinical trials that enroll patients across diseases and disease states, increasing our ability to study nondisease-specific outcomes in HSCT.

Acute graft-versus-host disease (GVHD) is the primary limitation of allogeneic hematopoietic cell transplantation, and once it develops, there are no reliable diagnostic tests to predict treatment outcomes. We hypothesized that 6 previously validated diagnostic biomarkers of GVHD (IL-2 receptor-α; tumor necrosis factor receptor-1; hepatocyte growth factor; IL-8; elafin, a skin-specific marker; and regenerating islet-derived 3-α, a gastrointestinal tract-specific marker) could discriminate between therapy responsive and nonresponsive patients and predict survival in patients receiving GVHD therapy. We measured GVHD biomarker concentrations from samples prospectively obtained at the initiation of treatment, day 14, and day 28, on a multicenter, randomized, 4-arm phase 2 clinical trial for newly diagnosed acute GVHD. We found that at each of 3 time points, GVHD onset, 2 weeks into treatment, and 4 weeks into treatment, a 6-protein biomarker panel predicted for the important clinical outcomes of day 28 posttherapy nonresponse and mortality at day 180 from onset. GVHD biomarker panels can be used for early identification of patients at high or low risk for treatment nonresponsiveness or death, and they may provide opportunities for early intervention and improved survival after hematopoietic cell transplantation. The study was registered in clinicaltrials.gov as NCT00224874.

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) play an important role in the control of chronic graft-versus-host disease (cGVHD). In this study, we examined telomere length and telomerase activity of Treg and conventional CD4(+) T cells (Tcon) in 61 patients who survived more than 2 years after allogeneic hematopoietic stem cell transplantation. Cell proliferation and expression of Bcl-2 were also measured in each subset. Treg telomere length was shorter and Treg telomerase activity was increased compared with Tcon (P < .0001). After transplantation, Treg were also more highly proliferative than Tcon (P < .0001). Treg number, telomerase activity, and expression of Bcl-2 were each inversely associated with severity of cGVHD. These data indicate that activation of telomerase is not sufficient to prevent telomere shortening in highly proliferative Treg. However, telomerase activation is associated with increased Bcl-2 expression and higher Treg numbers in patients with no or mild cGVHD. In contrast, patients with moderate or severe cGVHD have fewer Treg with lower levels of telomerase activity and Bcl-2 expression. These results suggest that failure to activate Treg telomerase may restrict proliferative capacity and increase apoptotic susceptibility, resulting in the loss of peripheral tolerance and the development of cGVHD.

Investigation of the effects of rituximab (anti-CD20) on B-cell-activating factor of the tumor necrosis factor family (BAFF) and B cells would better define the significance of B-cell homeostasis in chronic graft-versus-host disease (cGVHD) pathophysiology. We studied 20 cGVHD patients at a median of 25 months after rituximab treatment when most patients had recovered total B-cell numbers. A total of 55% of patients had stable/improved cGVHD, and total B-cell numbers in these patients were significantly higher compared with rituximab-unresponsive patients. Although total B-cell number did not differ significantly between cGVHD groups before rituximab, there was a proportional increase in B-cell precursors in patients who later had stable/improved cGVHD. After rituximab, BAFF levels increased in all patients. Coincident with B-cell recovery in the stable/improved group, BAFF/B-cell ratios and CD27(+) B-cell frequencies decreased significantly. The peripheral B-cell pool in stable/improved cGVHD patients was largely composed of naive IgD(+) B cells. By contrast, rituximab-unresponsive cGVHD patients had persistent elevation of BAFF and a predominance of circulating B cells possessing an activated BAFF-R(Lo)CD20(Lo) cell surface phenotype. Thus, naive B-cell reconstitution and decreased BAFF/B-cell ratios were associated with clinical response after rituximab in cGVHD. Our findings begin to delineate B-cell homeostatic mechanisms important for human immune tolerance.

Graft-versus-host disease (GVHD) is a significant complication of allogeneic stem cell transplantation (alloSCT). The proteasome inhibitor bortezomib has immunomodulatory properties of potential benefit for GVHD control. We undertook a phase 1 trial of bortezomib, tacrolimus, and methotrexate for GVHD prophylaxis after reduced-intensity conditioning alloSCT using human leukocyte antigen-mismatched unrelated donors. Twenty-three patients were enrolled. Bortezomib dose levels of 1, 1.3, and 1.5 mg/m2 were evaluated with 5, 3, and 5 patients, respectively. Ten additional patients were accrued at the 1.3 mg/m2 bortezomib dose level. Bortezomib-related toxicity was minimal. With a 12-month median follow-up, grade II-IV acute GVHD occurred in 3 patients, a 180-day cumulative incidence of 13%. Chronic GVHD occurred in 9 patients, a 1-year cumulative incidence of 41%. At 1-year, the nonrelapse mortality was zero, cumulative incidence of relapse/progression was 29%, and overall, progression-free, and event-free survival were 75%, 64%, and 59%, respectively. Bortezomib is a promising novel immunomodulatory agent in allogeneic transplantation. This study was registered at http://www.clinicaltrials.gov as #NCT00369226.

Acute graft-versus-host disease (aGVHD) is the primary limitation of allogeneic hematopoietic cell transplantation. Corticosteroids remain the standard initial therapy, yet only 25% to 41% of patients completely respond. This randomized, 4-arm, phase 2 trial was designed to identify the most promising agent(s) for initial therapy for aGVHD. Patients were randomized to receive methylprednisolone 2 mg/kg per day plus etanercept, mycophenolate mofetil (MMF), denileukin diftitox (denileukin), or pentostatin. Patients (n = 180) were randomized; their median age was 50 years (range, 7.5-70 years). Myeloablative conditioning represented 66% of transplants. Grafts were peripheral blood (61%), bone marrow (25%), or umbilical cord blood (14%); 53% were from unrelated donors. Patients who received MMF for prophylaxis (24%) were randomized to a non-MMF arm. At randomization, aGVHD was grade I to II (68%), III to IV (32%), and (53%) had visceral organ involvement. Day 28 complete response rates were etanercept 26%, MMF 60%, denileukin 53%, and pentostatin 38%. Corresponding 9-month overall survival was 47%, 64%, 49%, and 47%, respectively. Cumulative incidences of severe infections were as follows: etanercept 48%, MMF 44%, denileukin 62%, and pentostatin 57%. Efficacy and toxicity data suggest the use of MMF plus corticosteroids is the most promising regimen to compare against corticosteroids alone in a definitive phase 3 trial. This study is registered at http://www.clinicaltrials.gov as NCT00224874.

Chronic graft-versus-host disease (cGVHD) causes significant morbidity and mortality in patients otherwise cured of malignancy after hematopoietic stem cell transplantation (HSCT). The presence of alloantibodies and high plasma B cell-activating factor (BAFF) levels in patients with cGVHD suggest that B cells play a role in disease pathogenesis. We performed detailed phenotypic and functional analyses of peripheral B cells in 82 patients after HSCT. Patients with cGVHD had significantly higher BAFF/B-cell ratios compared with patients without cGVHD or healthy donors. In cGVHD, increasing BAFF concentrations correlated with increased numbers of circulating pre-germinal center (GC) B cells and post-GC "plasmablast-like" cells, suggesting in vivo BAFF dependence of these 2 CD27(+) B-cell subsets. Circulating CD27(+) B cells in cGVHD comprised in vivo activated B cells capable of IgG production without requiring additional antigen stimulation. Serial studies revealed that patients who subsequently developed cGVHD had delayed reconstitution of naive B cells despite persistent BAFF elevation as well as proportional increase in CD27(+) B cells in the first year after HSCT. These studies delineate specific abnormalities of B-cell homeostasis in patients with cGVHD and suggest that BAFF targeting agents may be useful in this disease.

Sirolimus is an effective agent used in graft-versus-host disease (GVHD) prophylaxis after allogeneic transplantation. It also has antiproliferative effects on vascular endothelium when used to coat coronary artery stents. We noted an excess of veno-occlusive disease (VOD) in a clinical trial, and retrospectively reviewed the records of 488 patients to determine the association between sirolimus and VOD. When used with cyclophosphamide/total body irradiation (Cy/TBI) conditioning, sirolimus is associated with an increased incidence of VOD (OR 2.35, P = .005). The concomitant use of methotrexate further increased this rate (OR 3.23, P < .001), while sirolimus without methotrexate was not associated with an increased risk of VOD (OR 1.55, P = .33). Mortality after VOD diagnosis was unaffected, and overall treatment-related mortality was lowest when sirolimus was used without methotrexate. Similar findings were noted in matched, related, and unrelated as well as mismatched donor subgroups. When used with busulfan-based conditioning, sirolimus use was associated with an even higher rate of VOD (OR 8.8, P = .008). Our findings suggest that sirolimus use is associated with VOD after TBI-based transplantation when used with methotrexate after transplantation. Sirolimus-based GVHD prophylaxis without methotrexate is associated with the greatest overall survival. Myeloablative doses of busulfan should not be used with sirolimus-based immunosuppression.

Idiopathic pneumonia syndrome (IPS) refers to a diffuse, noninfectious, acute lung injury after hematopoietic stem cell transplantation. Historically, IPS is associated with respiratory failure and mortality rates exceeding 50%. Preclinical studies have implicated tumor necrosis factor-alpha as an important effector molecule in the development of disease. We studied the tumor necrosis factor-alpha inhibitor, etanercept, combined with corticosteroids in treating 15 patients (median age, 18 years; range, 1-60 years) with IPS. Eight of 15 patients required mechanical ventilation at therapy onset. Etanercept was administered subcutaneously at a dose of 0.4 mg/kg (maximum 25 mg) twice weekly, for a maximum of 8 doses. Therapy was well tolerated with no infectious pulmonary complications noted. Ten of 15 patients had a complete response, defined as the ability to discontinue supplemental oxygen support during study therapy. The median time to complete response was 7 days (range, 3-18 days), with a day 28 survival of 73%. IPS onset was associated with elevations of several inflammatory proteins in the bronchoalveolar lavage fluid and plasma, and response to therapy correlated with reductions in pulmonary and systemic inflammation. The combination of etanercept and corticosteroids is safe and is associated with high response rates and improved survival in patients with IPS.

Despite improvements in our understanding of transplant immunology and clinical and supportive care, acute graft-versus-host disease (GVHD) remains a clinical challenge and a major cause of morbidity and mortality for patients after allogeneic hematopoietic stem-cell transplantation. While systemic corticosteroid is standard primary therapy for acute GVHD, there is no established standard treatment in the steroid-refractory setting. New generations of monoclonal antibodies, biologics, and chemotherapeutics with immunomodulatory effects have been developed over the past decade, and are being tested as novel therapies in this disease. Many of these agents - including, among others, mycophenolate mofetil, anti-tumor necrosis factor-alpha antibodies, denileukin diftitox, and anti-interleukin-2Ralpha-chain antibodies - have demonstrated promising activity in steroid-refractory acute GVHD. Despite the high response rates, however, long-term survival remains poor due to a high incidence of infections. The key to improving acute GVHD outcomes may, in fact, rest upon successful initial therapy, and timely taper of corticosteroids to promote healthier immune reconstitution. Clinical trials combining these newer agents with systemic corticosteroids as initial treatment are under way, and will determine whether fortifying initial therapy will indeed reduce the development of steroid-refractory GVHD and improve long-term outcomes. In this article, we review current and novel agents available for acute GVHD, and discuss newer investigational approaches - such as phototherapy and cellular therapies - in the management of this common transplant complication.

Sirolimus-based immunosuppressive regimens in organ transplantation have been associated with a lower than expected incidence of cytomegalovirus (CMV) disease. Whether sirolimus has a similar effect on CMV reactivation after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We evaluated 606 patients who underwent HSCT between April 2000 and June 2004 to identify risk factors for CMV reactivation 100 days after transplantation. The cohort included 252 patients who received sirolimus-tacrolimus for graft-versus-host disease (GVHD) prophylaxis; the rest received non-sirolimus-based regimens. An initial positive CMV DNA hybrid capture assay was observed in 225 patients (37.1%) at a median 39 days after HSCT for an incidence rate of 0.50 cases/100 patient-days (95% confidence interval [CI], 0.44-0.57). Multivariable Cox modeling adjusting for CMV donor-recipient serostatus pairs, incident acute GVHD, as well as other important covariates, confirmed a significant reduction in CMV reactivation associated with sirolimus-tacrolimus-based GVHD prophylaxis, with an adjusted HR of 0.46 (95% CI, 0.27-0.78; P = .004). The adjusted HR was 0.22 (95% CI, 0.09-0.55; P = .001) when persistent CMV viremia was modeled. Tacrolimus use without sirolimus was not significantly protective in either model (adjusted HR, 0.66; P = .14 and P = .35, respectively). The protective effect of sirolimus-containing GVHD prophylaxis regimens on CMV reactivation should be confirmed in randomized trials.

Iron overload could be a significant contributor to treatment-related mortality (TRM) for patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT). We studied 590 patients who underwent myeloablative allogeneic HSCT at our institution, and on whom a pretransplantation serum ferritin was available. An elevated pretransplantation serum ferritin level was strongly associated with lower overall and disease-free survival. Subgroup multivariable analyses demonstrated that this association was restricted to patients with acute leukemia or myelodysplastic syndrome (MDS); in the latter group, the inferior survival was attributable to a significant increase in TRM. There was also a trend toward an increased risk of veno-occlusive disease in patients with high ferritin. Our results argue that iron overload plays an important role in transplantation outcome for patients with acute leukemia or MDS, as it does in thalassemia. They also suggest future prospective trials to examine the potential benefit of chelation therapy in this setting.

We assessed the combination of sirolimus and tacrolimus without methotrexate after myeloablative allogeneic stem cell transplantation from 53 matched related donors (MRDs) and 30 unrelated donors (URDs). All patients received cyclophosphamide and total body irradiation conditioning followed by transplantation of mobilized peripheral blood stem cells. The median time to neutrophil engraftment was 14 days. The median time to platelet engraftment was 12 days. No differences between MRD and URD cohorts was noted. The incidence of grade II-IV and III-IV acute graft-versus-host disease (GVHD) were 20.5% and 4.8%. The cumulative incidence of chronic GVHD was 59.1%. There were no differences in acute or chronic GVHD incidence between MRD and URD cohorts. The omission of methotrexate was associated with low transplant-related toxicity, with 30-day and 100-day treatment-related mortality rates of 0% and 4.8%. Relapse-free survival at 1 and 2 years was 72.3% and 68.5%, respectively. Overall survival at 1 and 2 years was 77.1% and 72.2%, respectively. There were no differences in relapse-free or overall survival between MRD and URD cohorts. The substitution of sirolimus for methotrexate as GVHD prophylaxis is associated with rapid engraftment, a low incidence of acute GVHD, minimal transplant-related toxicity, and excellent survival. Differences between MRD and URD cohorts are not evident when effective GVHD prophylaxis is used.

The standard initial therapy for acute graft-versus-host disease (GVHD) is corticosteroids. Daclizumab is a humanized monoclonal antibody against the interleukin 2 (IL-2) receptor expressed on activated T lymphocytes. Because of daclizumab's favorable toxicity profile and response rate in steroid-resistant GVHD, a multicenter, double-blinded, randomized study of corticosteroids with or without daclizumab for initial treatment of acute GVHD was conducted. A total of 102 evaluable subjects of the targeted 166 were enrolled at 5 participating sites. Methylprednisolone at a dose of 2 mg/kg or daily equivalent was given in conjunction with daclizumab 1 mg/kg or placebo on study days 1, 4, 8, and weekly as long as clinically indicated. The groups were balanced for clinical characteristics. GVHD response rates by study day 42 were similar (53% vs 51%; P =.85). The study was halted after a planned interim analysis showed a significantly worse 100-day survival in the group receiving corticosteroids plus daclizumab (77% vs 94%; P =.02). Overall survival at 1 year was also inferior in the combination arm (29% vs 60%; P =.002). Both relapse- and GVHD-related mortality contributed to the increased mortality in the combination group. The combination of corticosteroids and daclizumab should not be used as initial therapy of acute GVHD.

Denileukin diftitox (Ontak), a recombinant protein composed of human interleukin 2 (IL-2) fused to diphtheria toxin, has selective cytotoxicity against activated lymphocytes expressing the high-affinity IL-2 receptor. We conducted a phase 1 study of denileukin diftitox in 30 patients with steroid refractory acute graft-versus-host disease (GVHD). Seven patients received 9 microg/kg intravenously on days 1 and 15; 18 received 9 microg/kg intravenously on days 1, 3, 5, 15, 17, and 19; and 5 received 9 microg/kg intravenously on days 1 to 5 and 15 to 19. Hepatic transaminase elevation was the dose-limiting toxicity (DLT), and dose level 2 was the maximum tolerated dose (MTD). Overall, 71% of patients responded with complete resolution (12 of 24; 50%) or partial resolution (5 of 24; 21%) of GVHD. Eight of 24 patients (33%) are alive at 6.3 to 24.6 months (median, 7.2 months). Denileukin diftitox is tolerable and has promising activity in steroid-refractory acute GVHD.

We studied the feasibility and activity of adding sirolimus to tacrolimus and low-dose methotrexate as graft-versus-host disease (GVHD) prophylaxis in recipients of alternative donor transplants. Forty-one patients with hematologic malignancies were conditioned with cyclophosphamide and total body irradiation. Marrow stem cells were from an HLA-A, -B, and -DR compatible, unrelated donor (n = 26, 68%), from a 5 of 6 antigen-matched unrelated donor (n = 8, 20%), or from a 5 of 6 antigen-matched family member (n = 5, 12%). Therapeutic serum levels of sirolimus were attained in most patients. All evaluable patients engrafted. An absolute neutrophil count of 500/microL was achieved on day +18 (range, 11-32 days). Sustained platelet counts of more than 20 000/ microL were attained on day +29 (range, 14-98 days). Grades 0-I acute GVHD occurred in 75% of patients. Grades II, III, and IV acute GVHD occurred in 13%, 8%, and 5%, respectively (total grades II-IV GVHD, 26%). Median survival is 366 days (95% CI 185, not estimable) and actuarial survival at 1 year is 52%. Oral sirolimus is tolerable, adequate blood levels are achievable, and there is a low rate of acute GVHD compared with historical data in this high-risk population. This novel agent is worthy of further study in allogeneic transplantation.

T-cell depletion (TCD) and immunosuppressive medications (ISTs) are 2 methods used for graft-versus-host disease (GVHD) prophylaxis in unrelated donor (URD) transplantation. However, comparisons of the clinical outcomes including quality of life and direct medical costs associated with each type of procedure have not been reported. We reviewed 48 TCD and 98 IST procedures performed from 1/1/97 to 12/31/99 at the Dana-Farber Cancer Institute, Boston, MA. With a median follow-up of 1.5 years for survivors, no differences were seen in relapse, acute GVHD, and overall survival between TCD and IST patients. Multivariable Cox modeling showed that age of 50 years or less (P =.002) and low-risk disease (P =.001) predicted survival, but method of GVHD prophylaxis (P =.6) and degree of human leukocyte antigen (HLA) matching (P =.8) did not. A subset of patients (53%) completed quality of life surveys prior to and at 6 and 12 months after transplantation; participation in the quality of life study was not associated with clinical characteristics and outcomes. No differences were seen in quality of life scores prior to transplantation, and changes over time were similar between groups. Costs ($113 000 vs $155 000, P <.0001) and total hospital days (34 vs 46, P =.0006) were significantly lower for patients undergoing TCD procedures. As prospective, randomized studies comparing methods of GVHD prophylaxis are performed, assessment of quality of life and costs should be included to fully understand the overall impact of each intervention.