Search

PurposeChronic graft-versus-host disease (cGVHD) is a significant cause of morbidity and mortality among patients after allogeneic hematopoietic stem cell transplant (HCT). The objective of our study was to determine if early assessment of matrix metalloproteinase-9 (MMP-9) and dry eye (DE) symptoms (via the DE Questionnaire-5 [DEQ-5]) had prognostic utility for the development of cGVHD and/or severe DE symptoms after HCT.Materials and methodsThis was a retrospective study of 25 individuals who underwent HCT and had MMP-9 (InflammaDry) and DEQ-5 performed on day 100 post-HCT (D + 100). Patients also completed the DEQ-5 at 6, 9, and 12 months post-HCT. The development of cGVHD was determined by chart review.ResultsOverall, 28% of patients developed cGVHD over a median follow-up of 229 days. At D + 100, 32% of patients had a positive MMP-9 in at least one eye and 20% had a DEQ-5 ≥6. However, neither the presence of a positive MMP-9 nor a DEQ-5 score ≥6 at D + 100 predicted the development of cGVHD (MMP-9: hazard ratio [HR]: 1.53, 95% confidence interval [CI]: 0.34-6.85, P = 0.58; DEQ-5 ≥6: HR: 1.00, 95% CI: 0.12-8.32, P = 1.00). In addition, neither of these measures predicted the development of severe DE symptoms (DEQ-5 ≥12) over time (MMP-9: HR: 1.77, 95% CI: 0.24-12.89, P = 0.58; DEQ-5 >6: HR: 0.03, 95% CI: 0.00-889.93, P = 0.49).ConclusionWithin our small cohort, DEQ-5 and MMP-9 assessment at D + 100 did not predict the development of cGVHD or severe DE symptoms.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is complicated by graft- versus-host disease (GVHD), which causes immune dysfunction and further delays immune reconstitution through its effects on primary and secondary lymphoid organs. Treatments to prevent GVHD and improve immune recovery following allo-HSCT are needed. Post-transplantation cyclophosphamide (PTCy) is a well-established and clinically widely used method for GVHD prophylaxis after HLA-matched as well as haploidentical allo-HSCT, as well as a promising strategy in the setting of mismatched unrelated donor allo-HSCT. Recently, regulatory T cells (Tregs), a critical subset for immune homeostasis and tolerance induction, have been evaluated for use as GVHD prophylaxis in experimental models and clinical trials. Natural killer (NK) cells are one of the first lymphoid populations to reconstitute following allo-HSCT and are important mediators of protective immunity against pathogens, and are also critical for limiting post-transplantation relapse of hematologic cancers. Several reports have noted that a delay in NK cell recovery may occur following experimental mouse allo-HSCT as well as after clinical allo-HSCT. Here we examined how 2 treatment strategies, PTCy and donor expanded Tregs (TrED), in experimental MHC-matched allo-HSCT affect NK recovery. Our experiments show that both strategies improved NK cell numbers, with PTCy slightly better than TrED, early after allo-HSCT (1 month) compared with untreated allo-HSCT recipients. Importantly, NK cell IFN-γ production and cytotoxic function, as reflected by CD107 expression as well as in vivo killing of NK-sensitive tumor cells, were improved using either PTCy or TrED versus control allo-HSCT recipients. In conclusion, both prophylactic treatments were found to be beneficial for NK recovery and NK cell function following MHC-matched minor antigen-mismatched experimental allo-HSCT. Improved NK recovery could help provide early immunity toward tumors and pathogens in these transplant recipients.

Invasive aspergillosis is the most common invasive mold infection following a hematopoietic cell transplant. Widespread use of antifungal prophylaxis has led to the increasing incidence of cryptic Aspergillus species. Aspergillus calidoustus is one of those emerging species and is notorious for multidrug resistance to antifungals. Here, we report a case of disseminated A. calidoustus infection in a hematopoietic stem cell transplant recipient who was successfully treated with combination therapy that included a novel antifungal.

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis in recipients of haploidentical and fully matched transplantations is on the increase. Published studies have reported an increased incidence of cytomegalovirus (CMV) infection with the use of PTCy. Limited data exist on the incidence and outcomes of infection with non-CMV herpesviruses (NCHV) in this setting. The aim of this study was to evaluate the cumulative incidence of NCHV infections and the association of NCHV infections with transplantation-specific outcomes in recipients of haploidentical transplantation with PTCy (HaploCy), matched sibling donor transplantation with PTCy (SibCy), and matched sibling donor transplantation with calcineurin inhibitor-based prophylaxis (SibCNI). We hypothesized that, like CMV infection, HaploCy recipients of also will have a higher risk of NCHV infections. Using the Center for International Blood and Marrow Transplantation Research database, we analyzed 2765 patients (HaploCy, n = 757; SibCNI, n = 1605; SibCy, n = 403) who had undergone their first hematopoietic stem cell transplantation (HCT) between 2012 and 2017 for acute myelogenous leukemia, acute lymphoblastic leukemia, or myelodysplastic syndrome. The cumulative incidence of NCHV at 6 months post-NCT was 13.9% (99% confidence interval], 10.8% to 17.3%) in the HaploCy group, 10.7% (99% CI, 7.1% to 15%) in the SibCy group, and 5.7% (99% CI, 4.3% to 7.3%) in the Sib CNI group (P < .001). This was due primarily to a higher frequency of human herpesvirus 6 viremia reported in patients receiving PTCy. The incidence of Epstein-Barr viremia was low in all groups, and no cases of post-transplantation lymphoproliferative disorder were seen in either PTCy group. The incidence of NCHV organ disease was low in all 3 cohorts. The development of NCHV infection was associated with increased treatment-related mortality, particularly in the HaploCy group. There was no association with the development of GVHD, relapse, or disease-free survival. Patients in PTCy cohorts who did not develop NCHV infection had lower rates of cGVHD. This study demonstrates that the use of PTCy is associated with an increased risk of NCHV infection. The development of NCHV infection was associated with increased nonrelapse mortality, especially in the HaploCy group. Prospective trials should consider viral surveillance strategies in conjunction with assessment of immune reconstitution for a better understanding of the clinical relevance of viral reactivation in different HCT settings.

Cytogenetic and molecular abnormalities are known to influence post-transplant outcomes in acute myeloid leukemia (AML) but data assessing the prognostic value of combined genetic models in the HCT setting are limited. We developed an adapted European LeukemiaNet (aELN) risk classification based on available genetic data reported to the Center for International Blood and Marrow Transplant Research, to predict post-transplant outcomes in 2289 adult AML patients transplanted in first remission, between 2013 and 2017. Patients were stratified according to aELN into three groups: favorable (Fav, N = 181), intermediate (IM, N = 1185), and adverse (Adv, N = 923). Univariate analysis demonstrated significant differences in 2-year overall survival (OS) (Fav: 67.7%, IM: 64.9% and Adv: 53.9%; p

ProblemThe utility of the polymerase chain reaction (PCR) cycle threshold (Ct ) values in the management of patients with coronavirus disease 2019 (COVID-19) remains controversial.MethodsWe assessed the correlation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Ct values in nasopharyngeal swab samples with the oxygen requirements at the time of sample collection. Specimens were tested with the Simplexa PCR platform, which targets the SARS-CoV-2 ORF1ab and S genes.ResultsWe identified 23 COVID-19 patients with 49 Ct values available. While Ct values from ORF1ab and S genes were highly correlated for a given specimen, there was no correlation between Ct values for any of these target genes and the oxygen requirements of the patient at the time of sample collection. We found no differences in the initial nor the nadir Ct values between survivors and non-survivors or mild/moderate versus severe/critical illness at the maximum point of illness.ConclusionSARS-CoV-2 Ct values have limited value in the management of COVID-19.

BackgroundOne year into the pandemic, published data on hematopoietic cell transplantation (HCT) recipients with coronavirus disease 2019 (COVID-19) remain limited.MethodsSingle-center retrospective cohort study of adult HCT recipients with polymerase chain reaction (PCR)-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.ResultsTwenty-eight consecutive transplantation and cellular therapy patients (autologous, n = 12; allogeneic, n = 15; chimeric antigen receptor T-cell therapy [CAR-T], n = 1) with COVID-19 were identified. The median age was 57 years. The median time from HCT to COVID-19 diagnosis was 656 days (interquartile range [IQR], 33-1274). Patients were followed for a median of 59 days (IQR, 40-88). Among assessable patients (n = 19), 10 (53%) had documented virological clearance; median time to clearance was 34 days (range, 21-56). Out of 28, 12 (43%), 6 (21%), and 10 (36%) patients had mild, moderate, and severe/critical disease, respectively. Overall mortality was 25%, nearly identical for autologous and allogeneic HCT, and exclusively seen in hospitalized patients, older than 50 years of age with severe COVID-19. None of the patients with mild (n = 12) or moderate (n = 6) COVID-19 died whereas 7/10 patients (70%) with severe/critical COVID-19 died (P = .0001). Patients diagnosed with COVID-19 within 12 months of HCT exhibited higher mortality (57% vs 14%; P = .04). All-cause 30-day mortality (n = 4) was 14%. A higher proportion of patients who died within 30 days of COVID-19 diagnosis (3/4) were receiving ≥2 immunosuppressants, compared with patients who survived beyond 30 days after COVID-19 diagnosis (2/24; 75% vs. 8%; P = .01).ConclusionsMortality in COVID-19 HCT patients is higher than that of the age-comparable general population and largely dependent on age, disease severity, timing from HCT, and intensity of immunosuppression.

Community respiratory viral infections (CRVIs) are associated with pulmonary function impairment, alloimmune lung syndromes and inferior survival in human leucocyte antigen (HLA)-matched allogeneic haematopoietic stem cell transplant (HCT) recipients. Although the incidence of viral infections in HLA-haploidentical HCT recipients who receive post-transplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis is reportedly increased, there are insufficient data describing the incidence of CRVIs and the impact of donor source and PTCy on transplant outcomes. Analysing patients receiving their first HCT between 2012 and 2017 for acute myeloid leukaemia, acute lymphoblastic leukaemia and myelodysplastic syndromes, we describe comparative outcomes between matched sibling transplants receiving either calcineurin-based GVHD prophylaxis (SibCNI, N = 1605) or PTCy (SibCy, N = 403), and related haploidentical transplants receiving PTCy (HaploCy, N = 757). The incidence of CRVIs was higher for patients receiving PTCy, regardless of donor type. Patients in the HaploCy cohort who developed a CRVI by day +180 had both a higher risk of treatment-related mortality [hazard ratio (HR) 2⋅14, 99% confidence interval (CI) 1⋅13-4⋅07; P = 0⋅002] and inferior 2-year overall survival (HR 1⋅65, 99% CI 1⋅11-2⋅43; P = 0⋅001) compared to SibCNI with no CRVI. This finding justifies further research into long-term antiviral immune recovery, as well as development of preventive and treatment strategies to improve long-term outcomes in such patients.

PurposeHematopoietic cell transplantation (HCT) is curative for hematologic disorders, but outcomes are historically inferior when using HLA-mismatched donors. Despite unrelated donor registries listing > 38 million volunteers, 25%-80% of US patients lack an HLA-matched unrelated donor, with significant disparity across ethnic groups. We hypothesized that HCT with a mismatched unrelated donor (MMUD) using post-transplant cyclophosphamide (PTCy), a novel strategy successful in overcoming genetic disparity using mismatched related donors, would be feasible and increase access to HCT.Patients and methodsWe performed a prospective phase II study of MMUD bone marrow HCT with PTCy for patients with hematologic malignancies. The primary end point was 1-year overall survival (OS), hypothesized to be 65% or better. 80 patients enrolled at 11 US transplant centers (December 2016-March 2019). Following myeloablative or reduced-intensity conditioning-based HCT, patients received PTCy on days +3, +4, with sirolimus and mycophenolate mofetil starting on day +5. We compared outcomes to Center for International Blood and Marrow Transplant Research contemporary controls receiving PTCy.ResultsNotably, 48% of patients enrolled were ethnic minorities. 39% of pairs were matched for 4-6 out of 8 HLA alleles. The primary end point was met, with 1-year OS of 76% (90% CI, 67.3 to 83.3) in the entire cohort, and 72% and 79% in the myeloablative and reduced-intensity conditioning strata, respectively. Secondary end points related to engraftment and graft-versus-host-disease were reached. Multivariate analysis comparing the study group with other mismatched HCT controls found no significant differences in OS.ConclusionOur prospective study demonstrates the feasibility and effectiveness of HCT with an MMUD in the setting of PTCy. Remarkably, nearly half of the study participants belonged to an ethnic minority population, suggesting this approach may significantly expand access to HCT.

Corneal transplantation (CT) is the most frequent type of solid organ transplant (SOT) performed worldwide. Unfortunately, immunological rejection is the primary cause of graft failure for CT and therefore advances in immune regulation to induce tolerance remains an unmet medical need. Recently, our work and others in pre-clinical studies found that cyclophosphamide (Cy) administered after ("post-transplant," PTCy) hematopoietic stem cell transplantation (HSCT), i.e., liquid transplants is effective for graft vs. host disease prophylaxis and enhances overall survival. Importantly, within the past 10 years, PTCy has been widely adopted for clinical HSCT and the results at many centers have been extremely encouraging. The present studies found that Cy can be effectively employed to prolong the survival of SOT, specifically mouse corneal allografts. The results demonstrated that the timing of PTCy administration is critical for these CT and distinct from the kinetics employed following allogeneic HSCT. PTCy was observed to interfere with neovascularization, a process critically associated with immune rejection of corneal tissue that ensues following the loss of ocular "immune privilege." PTCy has the potential to delete or directly suppress allo-reactive T cells and treatment here was shown to diminish T cell rejection responses. These PTCy doses were observed to spare significant levels of CD4+ FoxP3+ (Tregs) which were found to be functional and could readily receive stimulating signals leading to their in vivo expansion via TNFRSF25 and CD25 agonists. In total, we posit future studies can take advantage of Cy based platforms to generate combinatorial strategies for long-term tolerance induction.

Immune effector cell (IEC) therapies offer durable and sustained remissions in significant numbers of patients with hematological cancers. While these unique immunotherapies have improved outcomes for pediatric and adult patients in a number of disease states, as 'living drugs,' their toxicity profiles, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), differ markedly from conventional cancer therapeutics. At the time of article preparation, the US Food and Drug Administration (FDA) has approved tisagenlecleucel, axicabtagene ciloleucel, and brexucabtagene autoleucel, all of which are IEC therapies based on genetically modified T cells engineered to express chimeric antigen receptors (CARs), and additional products are expected to reach marketing authorization soon and to enter clinical development in due course. As IEC therapies, especially CAR T cell therapies, enter more widespread clinical use, there is a need for clear, cohesive recommendations on toxicity management, motivating the Society for Immunotherapy of Cancer (SITC) to convene an expert panel to develop a clinical practice guideline. The panel discussed the recognition and management of common toxicities in the context of IEC treatment, including baseline laboratory parameters for monitoring, timing to onset, and pharmacological interventions, ultimately forming evidence- and consensus-based recommendations to assist medical professionals in decision-making and to improve outcomes for patients.

Shingrix is poorly immunogenic following allogeneic hematopoietic cell transplantation independent of age, CD4, and B-cell recovery. In hematopoietic cell transplantation recipients with antibody response to the vaccine, varicella zoster virus reactivation risk is not null.

The stimulator of interferon genes (STING) pathway has been proposed as a key regulator of gastrointestinal homeostasis and inflammatory responses. Although STING reportedly protects against gut barrier damage and graft-versus-host disease (GVHD) after major histocompatibility complex (MHC)-mismatched allogeneic hematopoietic stem cell transplantation (aHSCT), its effect in clinically relevant MHC-matched aHSCT is unknown. Studies here demonstrate that STING signaling in nonhematopoietic cells promoted MHC-matched aHSCT-induced GVHD and that STING agonists increased type I interferon and MHC I expression in nonhematopoietic mouse intestinal organoid cultures. Moreover, mice expressing a human STING allele containing three single-nucleotide polymorphisms associated with decreased STING activity also developed reduced MHC-matched GVHD, demonstrating STING's potential clinical importance. STING-/- recipients experienced reduced GVHD with transplant of purified donor CD8+ T cells in both MHC-matched and MHC-mismatched models, reconciling the seemingly disparate results. Further examination revealed that STING deficiency reduced the activation of donor CD8+ T cells early after transplant and promoted recipient MHC class II+ antigen-presenting cell (APC) survival. Therefore, APC persistence in STING pathway absence may account for the increased GVHD mediated by CD4+ T cells in completely mismatched recipients. In total, our findings have important implications for regulating clinical GVHD by targeting STING early after aHSCT and demonstrate that an innate immune pathway has opposing effects on the outcome of aHSCT, depending on the donor/recipient MHC disparity.

BackgroundAngiosarcoma is an uncommon endothelial malignancy and a highly aggressive soft tissue sarcoma. Due to its infiltrative nature, successful management of localized angiosarcoma is often challenging. Systemic chemotherapy is used in the metastatic setting and occasionally in patients with high-risk localized disease in neoadjuvant or adjuvant settings. However, responses tend to be short-lived and most patients succumb to metastatic disease. Novel therapies are needed for patients with angiosarcomas.MethodsWe performed a retrospective analysis of patients with locally advanced or metastatic angiosarcoma, who were treated with checkpoint inhibitors at our institution. We collected their clinical information and outcome measurements. In one patient with achieved complete response, we analyzed circulating and infiltrating T cells within peripheral blood and tumor tissue.ResultsWe have treated seven angiosarcoma (AS) patients with checkpoint inhibitors either in the context of clinical trials or off label [Pembrolizumab + Axitinib (NCT02636725; n = 1), AGEN1884, a CTLA-4 inhibitor (NCT02694822; n = 2), Pembrolizumab (n = 4)]. Five patients had cutaneous angiosarcoma, one primary breast angiosarcoma and one radiation-associated breast angiosarcoma. At 12 weeks, 5/7 patients (71%) had partial response of their lesions either on imaging and/or clinical exam and two (29%) had progressive disease. 6/7 patients are alive to date and, thus far, 3/7 patients (43%) have progressed (median 3.4 months)- one achieved partial response after pembrolizumab was switched to ongoing Nivolumab/Ipilimumab, one died of progressive disease at 31 weeks (primary breast angiosarcoma) and one was placed on pazopanib. One patient had a complete response (CR) following extended treatment with monotherapy AGEN1884. No patient experienced any ≥ grade 2 toxicities.ConclusionsThis case series underscores the value of targeted immunotherapy in treating angiosarcoma. It also identifies genetic heterogeneity of cutaneous angiosarcomas and discusses specific genetic findings that may explain reported benefits from immunotherapy.

Following publication of the original article [1], the authors have reported that the following sentence "While of the same IgG1 class as ipilimumab, preclinical data suggests this molecule may have enhanced activity against T regulatory cells".

On August 30, 2017, the U.S. Food and Drug Administration (US-FDA) approved tisagenlecleucel (KYMRIAH, Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor-T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring and disease assessments. To address these issues, experts representing the American Society for Blood and Marrow Transplant (ASBMT), the European Group for Blood and Marrow Transplantation (EBMT), the International Society of Cell and Gene Therapy (ISCT), and the Foundation for the Accreditation of Cellular Therapy (FACT), formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.

Presumably, reduced-intensity/nonmyeloablative conditioning (RIC/NMA) for allogeneic hematopoietic cell transplantation (alloHCT) results in reduced infections compared with myeloablative conditioning (MAC) regimens; however, published evidence is limited. In this Center for International Blood and Marrow Transplant Research study, 1755 patients (aged ≥40 years) with acute myeloid leukemia in first complete remission were evaluated for infections occurring within 100 days after T-cell replete alloHCT. Patients receiving RIC/NMA (n = 777) compared with those receiving MAC (n = 978) were older and underwent transplantation more recently; however, the groups were similar regarding Karnofsky performance score, HCT-comorbidity index, and cytogenetic risk. One or more infections occurred in 1045 (59.5%) patients (MAC, 595 [61%]; RIC/NMA, 450 [58%]; P = .21) by day 100. The median time to initial infection after MAC conditioning occurred earlier (MAC, 15 days [range,

CD4+FoxP3+ regulatory T cells (Tregs) are a non-redundant population critical for the maintenance of self-tolerance. Over the past decade, the use of these cells for therapeutic purposes in transplantation and autoimmune disease has emerged based on their capacity to inhibit immune activation. Basic science discoveries have led to identifying key receptors on Tregs that can regulate their proliferation and function. Notably, the understanding that IL-2 signaling is crucial for Treg homeostasis promoted the hypothesis that in vivo IL-2 treatment could provide a strategy to control the compartment. The use of low-dose IL-2 in vivo was shown to selectively expand Tregs versus other immune cells. Interestingly, a number of other Treg cell surface proteins, including CD28, CD45, IL-33R and TNFRSF members, have been identified which can also induce activation and proliferation of this population. Pre-clinical studies have exploited these observations to prevent and treat mice developing autoimmune diseases and graft-versus-host disease post-allogeneic hematopoietic stem cell transplantation. These findings support the development of translational strategies to expand Tregs in patients. Excitingly, the use of low-dose IL-2 for patients suffering from graft-versus-host disease and autoimmune disease has demonstrated increased Treg levels together with beneficial outcomes. To date, promising pre-clinical and clinical studies have directly targeted Tregs and clearly established the ability to increase their levels and augment their function in vivo Here we review the evolving field of in vivo Treg manipulation and its application to allogeneic hematopoietic stem cell transplantation.

On August 30, 2017 the US Food and Drug Administration approved tisagenlecleucel (Kymriah; Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present, ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring, and disease assessments. To address these issues experts representing the American Society for Blood and Marrow Transplant, the European Society for Blood and Marrow Transplantation, the International Society of Cell and Gene Therapy, and the Foundation for the Accreditation of Cellular Therapy formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.

Background: Cell-free DNA (cfDNA) sequencing has emerged as an effective laboratory method for rapid and noninvasive diagnosis in prenatal screening testing, organ transplant rejection screening, and oncology liquid biopsies but clinical experience for use of this technology in diagnostic evaluation of infections in immunocompromised hosts is limited.  Methods: We conducted an exploratory study using next-generation sequencing (NGS) for detection of microbial cfDNA in a cohort of ten immunocompromised patients with febrile neutropenia, pneumonia or intra-abdominal infection.  Results: Pathogen identification by cfDNA NGS demonstrated positive agreement with conventional diagnostic laboratory methods in 7 (70%) cases, including patients with proven/probable invasive aspergillosis, Pneumocystis jirovecii pneumonia, Stenotrophomonas maltophilia bacteremia, Cytomegalovirus and Adenovirus viremia. NGS results were discordant in 3 (30%) cases including two patients with culture negative sepsis who had undergone hematopoietic stem cell transplant in whom cfDNA testing identified the potential etiological agent of sepsis; and one kidney transplant recipient with invasive aspergillosis who had received >6 months of antifungal therapy prior to NGS testing. Conclusion: These observations support the clinical utility of measurement of microbial cfDNA sequencing from peripheral blood for rapid noninvasive diagnosis of infections in immunocompromised hosts. Larger studies are needed.

Posttransplant cyclophosphamide (PTCy) has been found to be effective in ameliorating acute graft-versus-host disease (GVHD) in patients following allogeneic hematopoietic stem cell transplantation (aHSCT). Adoptive transfer of high numbers of donor Tregs in experimental aHSCT has shown promise as a therapeutic modality for GVHD regulation. We recently described a strategy for in vivo Treg expansion targeting two receptors: TNFRSF25 and CD25. To date, there have been no direct comparisons between the use of PTCy and Tregs regarding outcome and immune reconstitution within identical groups of transplanted mice. Here, we assessed these two strategies and found both decreased clinical GVHD and improved survival long term. However, recipients transplanted with Treg-expanded donor cells (TrED) exhibited less weight loss early after HSCT. Additionally, TrED recipients demonstrated less thymic damage, significantly more recent thymic emigrants, and more rapid lymphoid engraftment. Three months after HSCT, PTCy-treated and TrED recipients showed tolerance to F1 skin allografts and comparable immune function. Overall, TrED was found superior to PTCy with regard to weight loss early after transplant and initial lymphoid engraftment. Based on these findings, we speculate that morbidity and mortality after transplant could be diminished following TrED transplant into aHSCT recipients, and, therefore, that TrED could provide a promising clinical strategy for GVHD prophylaxis.

Regulatory T cells (Tregs) are essential for the maintenance of tolerance and immune homeostasis. In allogeneic hematopoietic stem cell transplantation (aHSCT), transfer of appropriate Treg numbers is a promising therapy for the prevention of graft-versus-host disease (GVHD). We have recently reported a novel approach that induces the marked expansion and selective activation of Tregs in vivo by targeting tumor necrosis factor receptor superfamily 25 (TNFRSF25) and CD25. A potential advance to promote clinical application of Tregs to ameliorate GVHD and other disorders would be the generation of more potent Treg populations. Here we wanted to determine if very low doses of Tregs generated using the "2-pathway" stimulation protocol via TL1A-Ig fusion protein and low-dose IL-2 (targeting TNFRSF25 and CD25, respectively) could be used to regulate preclinical GVHD. Analysis of such 2-pathway expanded Tregs identified higher levels of activation and functional molecules (CD103, ICOS-1, Nrp-1, CD39, CD73, il-10, and tgfb1) versus unexpanded Tregs. Additionally, in vitro assessment of 2-pathway stimulated Tregs indicated enhanced suppressor activity. Notably, transplant of extremely low numbers of these Tregs (1:6 expanded Tregs/conventional T cells) suppressed GVHD after an MHC-mismatched aHSCT. Overall, these results demonstrate that 2-pathway stimulated CD4+ FoxP3+ Tregs were quantitatively and qualitatively more functionally effective than unexpanded Tregs. In total, the findings in this study support the notion that such 2-pathway stimulated Tregs may be useful for prevention of GVHD and ultimately promote more widespread application of aHSCT in the clinic.

A recent approach for limiting production of pro-inflammatory cytokines has been to target bromodomain and extra-terminal (BET) proteins. These epigenetic readers of histone acetylation regulate transcription of genes involved in inflammation, cardiovascular disease, and cancer. Development of BET inhibitors (BETi) has generated enormous interest for their therapeutic potential. Because inflammatory signals and donor T cells promote graft-versus-host disease (GVHD), regulating both pathways could be effective to abrogate this disorder. The objective of the present study was to identify a BETi which did not interfere in vivo with CD4+FoxP3+ regulatory T cell (Treg) expansion and function to utilize together with Tregs following allogeneic hematopoietic stem cell transplantation (aHSCT) to ameliorate GVHD. We have reported that Tregs can be markedly expanded and selectively activated with increased functional capacity by targeting TNFRSF25 and CD25 with TL1A-Ig and low dose IL-2, respectively. Here, mice were treated over 7 days (TL1A-Ig + IL-2) together with BETi. We found that the BETi EP11313 did not decrease frequency/numbers or phenotype of expanded Tregs as well as effector molecules, such as IL-10 and TGF-β. However, BETi JQ1 interfered with Treg expansion and altered subset distribution and phenotype. Notably, in Treg expanded mice, EP11313 diminished tnfa and ifng but not il-2 RNA levels. Remarkably, Treg pSTAT5 expression was not affected by EP11313 supporting the notion that Treg IL-2 signaling remained intact. MHC-mismatched aHSCT (B6 → BALB/c) was performed using in vivo expanded donor Tregs with or without EP11313 short-term treatment in the recipient. Early post-transplant, improvement in the splenic and LN CD4/CD8 ratio along with fewer effector cells and high Treg levels in aHSCT recipients treated with expanded Tregs + EP11313 was detected. Interestingly, this group exhibited a significant diminution of GVHD clinical score with less skin and ocular involvement. Finally, using low numbers of highly purified expanded Tregs, improved clinical GVHD scores were observed in EP11313 treated recipients. In total, we conclude that use of this novel combinatorial strategy can suppress pre-clinical GVHD and posit, in vivo EP11313 treatment might be useful combined with Treg expansion therapy for treatment of diseases involving inflammatory responses.

Immunotherapy using T cells genetically engineered to express a chimeric antigen receptor (CAR) is rapidly emerging as a promising new treatment for haematological and non-haematological malignancies. CAR-T-cell therapy can induce rapid and durable clinical responses, but is associated with unique acute toxicities, which can be severe or even fatal. Cytokine-release syndrome (CRS), the most commonly observed toxicity, can range in severity from low-grade constitutional symptoms to a high-grade syndrome associated with life-threatening multiorgan dysfunction; rarely, severe CRS can evolve into fulminant haemophagocytic lymphohistiocytosis (HLH). Neurotoxicity, termed CAR-T-cell-related encephalopathy syndrome (CRES), is the second most-common adverse event, and can occur concurrently with or after CRS. Intensive monitoring and prompt management of toxicities is essential to minimize the morbidity and mortality associated with this potentially curative therapeutic approach; however, algorithms for accurate and consistent grading and management of the toxicities are lacking. To address this unmet need, we formed a CAR-T-cell-therapy-associated TOXicity (CARTOX) Working Group, comprising investigators from multiple institutions and medical disciplines who have experience in treating patients with various CAR-T-cell therapy products. Herein, we describe the multidisciplinary approach adopted at our institutions, and provide recommendations for monitoring, grading, and managing the acute toxicities that can occur in patients treated with CAR-T-cell therapy.

BackgroundIn a phase 1 trial, axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, showed efficacy in patients with refractory large B-cell lymphoma after the failure of conventional therapy.MethodsIn this multicenter, phase 2 trial, we enrolled 111 patients with diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, or transformed follicular lymphoma who had refractory disease despite undergoing recommended prior therapy. Patients received a target dose of 2×106 anti-CD19 CAR T cells per kilogram of body weight after receiving a conditioning regimen of low-dose cyclophosphamide and fludarabine. The primary end point was the rate of objective response (calculated as the combined rates of complete response and partial response). Secondary end points included overall survival, safety, and biomarker assessments.ResultsAmong the 111 patients who were enrolled, axi-cel was successfully manufactured for 110 (99%) and administered to 101 (91%). The objective response rate was 82%, and the complete response rate was 54%.With a median follow-up of 15.4 months, 42% of the patients continued to have a response, with 40% continuing to have a complete response. The overall rate of survival at 18 months was 52%. The most common adverse events of grade 3 or higher during treatment were neutropenia (in 78% of the patients), anemia (in 43%), and thrombocytopenia (in 38%). Grade 3 or higher cytokine release syndrome and neurologic events occurred in 13% and 28% of the patients, respectively. Three of the patients died during treatment. Higher CAR T-cell levels in blood were associated with response.ConclusionsIn this multicenter study, patients with refractory large B-cell lymphoma who received CAR T-cell therapy with axi-cel had high levels of durable response, with a safety profile that included myelosuppression, the cytokine release syndrome, and neurologic events. (Funded by Kite Pharma and the Leukemia and Lymphoma Society Therapy Acceleration Program; ZUMA-1 ClinicalTrials.gov number, NCT02348216 .).

Immune reconstitution after hematopoietic stem cell transplantation (HCT) beyond 1 year is not completely understood. Many transplant recipients who are free of graft-versus-host disease (GVHD) and not receiving any immunosuppression more than 1 year after transplantation seem to be able to mount appropriate immune responses to common pathogens and respond adequately to immunizations. However, 2 large registry studies over the last 2 decades seem to indicate that infection is a significant cause of late mortality in some patients, even in the absence of concomitant GVHD. Research on this topic is particularly challenging for several reasons. First, there are not enough long-term follow-up clinics able to measure even basic immune parameters late after HCT. Second, the correlation between laboratory measurements of immune function and infections is not well known. Third, accurate documentation of infectious episodes is notoriously difficult. Finally, it is unclear what measures can be implemented to improve the immune response in a clinically relevant way. A combination of long-term multicenter prospective studies that collect detailed infectious data and store samples as well as a national or multinational registry of clinically significant infections (eg, vaccine-preventable severe infections, opportunistic infections) could begin to address our knowledge gaps. Obtaining samples for laboratory evaluation of the immune system should be both calendar and eventdriven. Attention to detail and standardization of practices regarding prophylaxis, diagnosis, and definitions of infections would be of paramount importance to obtain clean reliable data. Laboratory studies should specifically address the neogenesis, maturation, and exhaustion of the adaptive immune system and, in particular, how these are influenced by persistent alloreactivity, inflammation, and viral infection. Ideally, some of these long-term prospective studies would collect information on long-term changes in the gut microbiome and their influence on immunity. Regarding enhancement of immune function, prospective measurement of the response to vaccines late after HCT in a variety of clinical settings should be undertaken to better understand the benefits as well as the limitations of immunizations. The role of intravenous immunoglobulin is still not well defined, and studies to address it should be encouraged.

Regulatory T cells (Tregs) are critical for self-tolerance. Although adoptive transfer of expanded Tregs limits graft-versus-host disease (GVHD) after hematopoietic stem cell transplantation (HSCT), ex vivo generation of large numbers of functional Tregs remains difficult. Here, we demonstrate that in vivo targeting of the TNF superfamily receptor TNFRSF25 using the TL1A-Ig fusion protein, along with IL-2, resulted in transient but massive Treg expansion in donor mice, which peaked within days and was nontoxic. Tregs increased in multiple compartments, including blood, lymph nodes, spleen, and colon (GVHD target tissue). Tregs did not expand in bone marrow, a critical site for graft-versus-malignancy responses. Adoptive transfer of in vivo-expanded Tregs in the setting of MHC-mismatched or MHC-matched allogeneic HSCT significantly ameliorated GVHD. Critically, transplantation of Treg-expanded donor cells facilitated transplant tolerance without GVHD, with complete sparing of graft-versus-malignancy. This approach may prove valuable as a therapeutic strategy promoting transplantation tolerance.

Ocular complications occur after transplantation in 60% to 90% of chronic graft-versus-host disease (GVHD) patients and significantly impair vision-related quality of life. Ocular surface inflammation and dry eye disease are the most common manifestations of ocular GVHD. Ocular GVHD can be viewed as an excellent preclinical model that can be studied to understand the immune pathogenesis of this common and debilitating disease. A limitation of this is that only a few experimental models mimic the ocular complications after hematopoietic stem cell transplantation (HSCT) and have focused on the acute GVHD process. To address this issue, we used a preclinical animal model developed by our group where ocular involvement was preceded by systemic GVHD to gain insight regarding the contributing immune mechanisms. Employing this "matched unrelated donor" model enabled the development of clinical scoring criteria, which readily identified different degrees of ocular pathology at both the ocular surface and adnexa, dependent on the level of conditioning before HSCT. As far as we are aware, we report for the first time that these clinical and immune responses occur not only on the ocular surface, but they also heavily involve the lid margin region. In total, the present study reports a preclinical scoring model that can be applied to animal models as investigators look to further explore GVHD's immunologic effects at the level of the ocular surface and eyelid adnexa compartments. We speculate that future studies will use this clinical scoring index in combination with what is recognized histologically and correlated with serum biomarkers identified in chronic/ocular GVHD.

Alternative graft sources (umbilical cord blood [UCB], matched unrelated donors [MUD], or mismatched unrelated donors [MMUD]) enable patients without a matched sibling donor to receive potentially curative hematopoietic cell transplantation (HCT). Retrospective studies demonstrate comparable outcomes among different graft sources. However, the risk and types of infections have not been compared among graft sources. Such information may influence the choice of a particular graft source. We compared the incidence of bacterial, viral, and fungal infections in 1781 adults with acute leukemia who received alternative donor HCT (UCB, n= 568; MUD, n = 930; MMUD, n = 283) between 2008 and 2011. The incidences of bacterial infection at 1 year were 72%, 59%, and 65% (P

Following the advent of molecular assays that measure T cell receptor excision circles (TRECs) present in recent thymic emigrants, it has been conclusively shown that thymopoiesis persists in most adults, but that functional output decreases with age, influencing the maintenance of a diverse and functional T cell receptor (TCR) repertoire. Space flight has been shown to result in a variety of phenotypic and functional changes in human T cells and in the reactivation of latent viruses. While space flight has been shown to influence thymic architecture in rodents, thymopoiesis has not previously been assessed in astronauts. Here, we assessed thymopoiesis longitudinally over a 1-year period prior to and after long-term space flight (median duration, 184 days) in 16 astronauts. While preflight assessments of thymopoiesis remained quite stable in individual astronauts, we detected significant suppression of thymopoiesis in all subjects upon return from space flight. We also found significant increases in urine and plasma levels of endogenous glucocorticoids coincident with the suppression of thymopoiesis. The glucocorticoid induction and thymopoiesis suppression were transient, and they normalized shortly after return to Earth. This is the first report to our knowledge to prospectively demonstrate a significant change in thymopoiesis in healthy individuals in association with a defined physiologic emotional and physical stress event. These results suggest that suppression of thymopoiesis has the potential to influence the maintenance of the TCR repertoire during extended space travel. Further studies of thymopoiesis and endogenous glucocorticoids in other stress states, including illness, are warranted.

The efficacy of allogeneic hematopoietic stem cell transplantation for hematologic malignancies is limited by the difficulty in suppressing graft-versus-host disease (GVHD) without compromising graft-versus-tumor (GVT) effects. We previously showed that RAS/MEK/ERK signaling depends on memory differentiation in human T cells, which confers susceptibility to selective inhibition of naive T cells. Actually, antineoplastic MEK inhibitors selectively suppress alloreactive T cells, sparing virus-specific T cells in vitro. Here, we show that trametinib, a MEK inhibitor clinically approved for melanoma, suppresses GVHD safely without affecting GVT effects in vivo. Trametinib prolonged survival of GVHD mice and attenuated GVHD symptoms and pathology in the gut and skin. It inhibited ERK1/2 phosphorylation and expansion of donor T cells, sparing Tregs and B cells. Although high-dose trametinib inhibited myeloid cell engraftment, low-dose trametinib suppressed GVHD without severe adverse events. Notably, trametinib facilitated the survival of mice transplanted with allogeneic T cells and P815 tumor cells with no residual P815 cells observed in the livers and spleens, whereas tacrolimus resulted in P815 expansion. These results confirm that trametinib selectively suppresses GVHD-inducing T cells while sparing antitumor T cells in vivo, which makes it a promising candidate for translational studies aimed at preventing or treating GVHD.

The American Society for Blood and Marrow Transplantation (ASBMT) Clinical Case Forum (CCF) was launched in 2014 as an online secure tool to enhance interaction and communication among hematopoietic cell transplantation (HCT) professionals worldwide through the discussion of challenging clinical care issues. After 14 months, we reviewed clinical and demographical data of cases posted in the CCF from January 29, 2014 to March 18, 2015. A total of 137 cases were posted during the study period. Ninety-two cases (67%) were allogeneic HCT, 29 (21%) were autologous HCT, and in 16 (12%), the type of transplantation (autologous versus allogeneic) was still under consideration. The diseases most frequently discussed included non-Hodgkin lymphoma (NHL; n = 30, 22%), acute myeloid leukemia (n = 23, 17%), and multiple myeloma (MM; n = 20, 15%). When compared with the US transplantation activity reported by the US Department of Health and Human Services, NHL and acute lymphoblastic leukemia cases were over-represented in the CCF, whereas MM was under-represented (P < .001). A total of 259 topics were addressed in the CCF with a median of 2 topics/case (range, 1 to 6). Particularly common topics included whether transplantation was indicated (n = 57, 41%), conditioning regimen choice (n = 44, 32%), and post-HCT complications after day 100 (n = 43, 31%). The ASBMT CCF is a successful tool for collaborative discussion of complex cases in the HCT community worldwide and may allow identification of areas of controversy or unmet need from clinical, educational and research perspectives.

The diagnosis and risk stratification of acute myeloid leukemia (AML) primarily rely on morphologic analysis and assessment of karyotype by chromosome banding analysis. For decades, standard AML induction therapy has utilized the combination of anthracyclines and cytarabine. Despite the use of postremission therapy, less than half of patients with AML will be cured of their disease. Allogeneic hematopoietic stem cell transplantation combines cytoreductive chemotherapy with adoptive immunotherapy and may cure patients who fail chemotherapy alone. Recent advances in next-generation sequencing have yielded important insights into the molecular landscape of AML with normal karyotype. Integrated prognostic models incorporating somatic mutation analyses may outperform prediction based on conventional clinical and cytogenetic factors alone. We review the evolution of risk profiling of AML from the cytogenetic to molecular era and describe the implications for AML diagnosis and postremission therapy.

PurposeThe primary objective of the present study was to identify the kinetics and origin of ocular infiltrating T cells in a preclinical model of graft-versus-host disease (GVHD) that induces eye tissue damage.MethodsGraft-versus-host disease was induced using an major histocompatibility complex (MHC)-matched, minor histocompatibility-mismatched hematopoietic stem cell transplant (HSCT) model. This approach, which utilized congenic and EGFP-labeled donor populations, mimics a matched, clinically unrelated donor (MUD) cell transplant. Systemic and ocular GVHD were assessed at varying time points using clinical examination, intravital microscopy, immune phenotype via flow cytometric analyses, and immunohistochemical staining.ResultsFollowing transplant, we observed characteristic changes in GVHD-associated immune phenotype as well as clinical signs present in recipients post transplant. Notably, the kinetics of the systemic changes and the ocular damage paralleled what is observed clinically, including damage to the cornea as well as the conjunctiva and lacrimal gland. Importantly, the infiltrate contained predominantly donor CD4 as well as CD8 T cells with an activated phenotype and macrophages together with effector cytokines consistent with the presence of a TH1 alloreactive population.ConclusionsOverall, the findings here unequivocally demonstrated that donor T cells compose part of the corneal and ocular adnexa infiltrate in animals undergoing ocular GVHD. In total, the results describe a novel and promising preclinical model characterized by both systemic and ocular changes as detected in significant numbers of patients undergoing GVHD following allo-HSCT, which can help facilitate dissecting the underlying immune mechanisms leading to damage associated with ocular GVHD.

Reduced-intensity conditioning (RIC) regimens have the potential to decrease transplantation-related morbidity and mortality. However, engraftment failure has been prohibitively high after RIC unrelated umbilical cord blood transplantation (UCBT) in chemotherapy-naïve children with nonmalignant diseases (NMD). Twenty-two children with a median age of 2.8 years, many with severe comorbidities and prior viral infections, were enrolled in a novel RIC protocol consisting of hydroxyurea, alemtuzumab, fludarabine, melphalan, and thiotepa followed by single UCBT. Patients underwent transplantation for inherited metabolic disorders (n = 8), primary immunodeficiencies (n = 9), hemoglobinopathies (n = 4) and Diamond Blackfan anemia (n = 1). Most umbilical cord blood (UCB) units were HLA-mismatched with median infused total nucleated cell dose of 7.9 × 10(7)/kg. No serious organ toxicities were attributable to the regimen. The cumulative incidence of neutrophil engraftment was 86.4% (95% confidence interval [CI], 65% to 100%) in a median of 20 days, with the majority sustaining > 95% donor chimerism at 1 year. Cumulative incidence of acute graft-versus-host disease (GVHD) grades II to IV and III to IV by day 180 was 27.3% (95% CI, 8.7% to 45.9%) and 13.6% (95 CI, 0% to 27.6%), respectively. Cumulative incidence of extensive chronic GVHD was 9.1% (95% CI, 0% to 20.8%). The primary causes of death were viral infections (n = 3), acute GVHD (n = 1) and transfusion reaction (n = 1). One-year overall and event-free survivals were 77.3% (95% CI, 53.7% to 89.8%) and 68.2% (95% CI, 44.6% to 83.4%) with 31 months median follow-up. This is the first RIC protocol demonstrating durable UCB engraftment in children with NMD. Future risk-based modifications of this regimen could decrease the incidence of viral infections. (www.clinicaltrials.gov/NCT00744692).