Plasma elevations of tumor necrosis factor-receptor-1 at day 7 postallogeneic transplant correlate with graft-versus-host disease severity and overall survival in pediatric patients

Monitoring of strength, inflammation and muscle function in allogenic stem-cell transplantation patients - a pilot study for novel biomarker and risk stratification determination

Background

Low aerobic capacity is associated with an increased mortality risk in allogenic stem-cell transplantation (alloSCT) patients, but currently used risk scores in the pre-transplantation workup are still underestimating physical activity as a prognostic factor.

Aim

To examine the physical condition, muscle function, blood inflammation and training adherence of alloSCT patients during inpatient time to identify potential biomarkers associated with development of myopathy and sarcopenia.

Methods

Patients undergoing alloSCT were examined at four time points (T0: before alloSCT; T_ha: hospital admission; T1: engraftment; T2: inpatient discharge). T0 included cardiopulmonary performance, body composition, grip and knee strength, motor skill tests (One-leg stand/Tinetti/Chair-rising), blood sampling (blood cell profiling and inflammation targets (Kynurenin/high sensitivity C-reactive Protein (hsCRP)/Tumor necrosis factor alpha (TNF-alpha)/Musclin/Galectin-3) and quality of life, state of health, fatigue, muscle weakness and physical activity by questionnaires (IPAQ/BSA/SARC-F/Fatigue). At T1 and T2, blood samples, grip strength and motor skill tests were repeated. Glucocorticoid dose and daily physical activity were documented during inpatient stay.

Results

26 of 35 included patients (4 females; age 55.58 ± 12.32 years; BMI 24.70 ± 3.27 kg/m²; VO_2peak 16.55 ± 4.06 ml/min/kg) could proceed to alloSCT. Grip strength and Tinetti decreased from T0 until T2, no difference in Chair-rising test, One-leg and Tandem stand. All patients engrafted after 24.9 days ± 3.9 days. HsCRP and Kynurenine increased from T0 to T1, decreased at T2. TNF-alpha (T0vsT2/T1vsT2) and Musclin (T0vsT1) decreased. At T2, Galectin-3 was higher compared to T0/T1. Correlation analysis of grip strength and inflammatory markers revealed a positive correlation with TNF-alpha at T2. 50% of patients documented physical activity and questionnaire and reported a 50%-reduction of daily endurance and strength training between T1 to T2.

Conclusion

Allogeneic stem-cell transplantation is associated with immune system vulnerability due to conditioning, increased inflammation and fatigue, and loss of muscle strength and function. In addition to hsCRP, Kynurenine seems to be a reliable biomarker to monitor acute and regenerative inflammation status of alloSCT patients, while Musclin and Galectin-3 may be added to physiological assessment regarding myopathy and sarcopenia. Grip strength and daily activity level should be documented by professionals to identify risk patients early and support them with optimal (exercise) therapy.

Acute GVHD Diagnosis and Adjudication in a Multicenter Trial: A Report From the BMT CTN 1202 Biorepository Study

PURPOSE

Accurate and reproducible methods to diagnose, grade, and report acute graft-versus-host disease (GVHD) are critical for the evaluation of therapies and biomarkers.

PATIENTS AND METHODS

The Blood and Marrow Transplant Clinical Trials Network 1202 study is an observational study of 1,709 allogeneic hematopoietic cell transplantation recipients that implemented weekly data reporting and near real-time data adjudication by an end point review committee (ERC), assigning a confidence level (confirmed, probable, possible, or negative) to the diagnosis of acute GVHD at onset.

RESULTS

During the first 100 days, symptoms consistent with GVHD developed in 90% of cases but were often determined by centers to be due to causes other than GVHD. Indeed, GVHD was under consideration in only 23% of cases at symptom onset. Diagnostic biopsies were obtained in 40% of cases, but treatment often was incongruous with biopsy findings and 10.5% of biopsies were equivocal. Importantly, more than 40% of steroid courses were started for reasons other than GVHD. The ERC modified the determination of GVHD diagnosis and/or grade in 12.3% of onset cases. The cumulative incidence of acute GVHD as reported by the centers was 62%. When the ERC adjudicated GVHD onset to be present only if the confidence level was probable or confirmed, the incidence of GVHD declined to 49%.

CONCLUSION

This study demonstrates that the incidence of GVHD may be overestimated at symptom onset, establishes a contemporary benchmark for acute GVHD, and suggests a structured framework for reporting and adjudication of GVHD that could be used in prospective trials.

Biomarkers for acute and chronic graft versus host disease: state of the art

INTRODUCTION

Despite significant advances in treatment and prevention, graft-versus-host disease (GVHD) still represents the main cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Thus, considerable research efforts have been made to find and validate reliable biomarkers for diagnosis, prognosis, and risk stratification of GVHD.

AREAS COVERED

In this review the most recent evidences on different types of biomarkers studied for GVHD, such as genetic, plasmatic, cellular markers, and those associated with microbiome, were summarized. A comprehensive search of peer-review literature was performed in PubMed including meta-analysis, preclinical and clinical trials, using the terms: cellular and plasma biomarkers, graft-versus-host disease, cytokines, and allogeneic hematopoietic stem cell transplantation.

EXPERT OPINION

In the near future, several validated biomarkers will be available to help clinicians in the diagnosis of GVHD, the identification of patients at high risk of GVHD development and in patients' stratification according to its severity. Then, immunosuppressive treatment could be tailored to each patient's real needs. However, more efforts are needed to achieve this goal. Although most of the proposed biomarkers currently lack validation with large-scale clinical data, their study led to improved knowledge of the biological basis of GVHD, and ultimately to implementation of GHVD treatment.

Targeting Signal 3 Extracellularly and Intracellularly in Graft-Versus-Host Disease

Allogeneic hematopoietic stem cell transplantation (allo-HCT) holds curative potential for many hematological disorders. However, the pathophysiology of the desired graft-versus-tumor effect is linked to life-threatening complications of acute graft-versus-host disease (GVHD). Allogeneic donor T lymphocytes are essential for causing GVHD, and their activation relies on the coordination of TCR engagement and co-stimulation, also known as Signal 1 and Signal 2. In addition to these signals, a network of secreted cytokines by immune cells provides a third signal, Signal 3, that is critical for the initiation and maintenance of GVHD. Strategies to target Signal 3 in human diseases have shown therapeutic benefit for inflammatory disorders such as Rheumatoid Arthritis and Inflammatory Bowel Disease. However, despite our growing understanding of their role in GVHD, the success of targeting individual cytokines has been modest with some notable exceptions. This review aims to describe current approaches toward targeting Signal 3 in clinical GVHD, and to highlight emerging studies in immune cell biology that may be harnessed for better clinical translation.

Prevention and Treatment of Acute Graft-versus-Host Disease in Children, Adolescents, and Young Adults

Acute graft-versus-host disease (GVHD) continues to be a major cause of morbidity and mortality after allogeneic hematopoietic cell transplant (HCT) in pediatric patients (ie, children and adolescent and young adults) and limits broader application of the therapy. Pediatric HCT patients have faced major obstacles to access clinical trials that test new agents for GVHD prevention and treatment. According to a recent search, only 6 clinical trials of interventions for prevention or treatment of acute GVHD were conducted specifically in pediatric patients in the United States over the past decade, with 8 internationally. In this review, we summarize the studies that were performed and specifically enrolled and reported on pediatric patients after allogeneic HCT and provide a listing of studies currently under way.

Targeting Regulatory T Cells by Addressing Tumor Necrosis Factor and Its Receptors in Allogeneic Hematopoietic Cell Transplantation and Cancer

An intricate network of molecular and cellular actors orchestrates the delicate balance between effector immune responses and immune tolerance. The pleiotropic cytokine tumor necrosis factor-alpha (TNF) proves as a pivotal protagonist promoting but also suppressing immune responses. These opposite actions are accomplished through specialist cell types responding to TNF via TNF receptors TNFR1 and TNFR2. Recent findings highlight the importance of TNFR2 as a key regulator of activated natural FoxP3⁺ regulatory T cells (Tregs) in inflammatory conditions, such as acute graft-vs.-host disease (GvHD) and the tumor microenvironment. Here we review recent advances in our understanding of TNFR2 signaling in T cells and discuss how these can reconcile seemingly conflicting observations when manipulating TNF and TNFRs. As TNFR2 emerges as a new and attractive target we furthermore pinpoint strategies and potential pitfalls for therapeutic targeting of TNFR2 for cancer treatment and immune tolerance after allogeneic hematopoietic cell transplantation.

Blockade of TNFα to Improve Human CD34+ Cell Repopulating Activity in Allogeneic Stem Cell Transplantation

Early release of TNFα after hematopoietic stem cell transplantation (HSCT) correlates with development of acute graft-vs.-host disease (GVHD). Here we tested the effect of TNFα and alloreactive T cells on early hematopoietic HSC genotype and function. Addition of TNFα (10 ng/ml) in liquid cultures with CD34+ cells for 6–72 h resulted in the downregulation of genes associated with stem cell activity, such as DNMT3A, DNMT3B, TET1, TET2, SOX2, NANOG, and OCT4, whereas no significant effect was observed on DNMT1 and GATA2 expression. These findings were reversed by using an anti-TNFα antibody. Similar gene downregulation was observed when CD34+ cells were co-cultured with alloreactive T cells CD34+ cells for 48–72 h, and this effect was partially prevented by rapamycin and an anti-TNFα antibody. CD34+ cells pre-incubated with TNFα for 48 h and transplanted in irradiated NOD-SCID ɤ^null (NSG) mice showed a reduced myeloid engraftment compared to control mice. By using a xenograft model recently developed in our lab, we co-transplanted CD34+ cells and allogeneic T lymphocytes at 1:0.1 ratio in one group that also received etanercept (TNFα inhibitor) at 100 μg intra-peritoneum (i.p.) on days −1,+1,+3,+5 post-HSCT, and in the control group. At 6 weeks post-transplant, mice that received etanercept had a significantly higher number of marrow huCD45+CD34+CD38- early stem cells (p = 0.03) and a reduced number of huCD45+CD3+ splenic T cells (p = 0.04) compared to controls. The repopulating activity of marrow cells from mice treated with etanercept vs. controls was tested in secondary transplants. Although the overall engraftment was similar in the two groups, CD34+ cells isolated from recipients of marrow from the etanercept group showed a significantly greater expression of stem cell-associated genes and a higher number of CD45+CD34+CD38- cells than in controls (p = 0.03). Our findings suggest that early TNFα increase post-transplant can affect long-term stem cell engraftment, and that blockade of TNFα early after transplant may limit a cytokine-mediated suppressive effect on repopulating stem cell function.

Etanercept as Treatment of Steroid-Refractory Acute Graft-versus-Host Disease in Pediatric Patients

Corticosteroids are the standard of care for first-line treatment of patients who develop grade II-IV of acute graft-versus-host disease (aGVHD), but the optimal second-line treatment has not yet been determined. We prospectively evaluated the use of the anti-TNFα monoclonal antibody etanercept (ET) as second-line treatment in children with steroid-refractory (SR) aGVHD. Twenty-five children with either malignant or nonmalignant diseases experiencing grade II-IV SR aGVHD received ET as second-line treatment. ET was administered after a median of 14days (range, 5 to 135 days) from the onset of aGVHD. Seventeen out of 25 patients (68%) developed a complete response (CR) or partial response (PR) to ET. The overall response rate (CR plus PR) was 78% in patients with cutaneous SR aGVHD, 78% in those with gastrointestinal aGVHD, and 57% in those with hepatic aGVHD. On day +100 after the start of ET, 52% of the children were in CR, 16% were in PR, and the remaining 32% failed to respond. Overall survival was 76.5% in responders and 16.7% in nonresponders (P = .004). Transplantation-related mortality at 5years was 34.1% (95% confidence interval, 18.6% to 57.1%). In our experience, ET has proven to be effective as second-line treatment in children with SR aGVHD.

Associations between febrile neutropenia-related parameters and the risk of acute GVHD or non-relapse mortality after allogeneic hematopoietic stem cell transplantation

Infection and inflammation can induce acute graft-vs.-host disease (aGVHD). We hypothesized that febrile neutropenia early after allogeneic hematopoietic cell transplantation (HCT) would increase the risk of aGVHD and non-relapse mortality (NRM). We retrospectively evaluated the impact of fever, C-reactive protein (CRP) concentration and blood stream infection (BSI) early after HCT on the incidence of grade II-IV aGVHD and NRM in 227 patients. Within 7 days after HCT, 91 (40.1%) patients experienced fever for at least 2 days (early-FN group). BSI occurred in 27 (11.9%) patients and the maximum CRP concentration was 2.57 mg/dl in the median. In a multivariate analysis, early-FN (hazard ratio (HR) 1.81, P = 0.007) and older recipient age (HR 1.68, P = 0.019) were significantly associated with the incidence of grade II-IV aGVHD. High-CRP and BSI were not significant risk factors for grade II-IV aGVHD. On the other hand, high-CRP was significantly associated with the incidence of NRM (HR 2.67, P = 0.004) in a multivariate analysis. In conclusion, although fever, CRP elevation and BSI are considered to be closely related events, they had different effects on the incidence of aGVHD and NRM. The development of early-FN after HCT may predict the risk of aGVHD.

Defining success with cellular therapeutics: the current landscape for clinical end point and toxicity analysis

Cellular therapies play a major and expanding role in the treatment of hematologic diseases. For each of these therapies, a narrow therapeutic window exists, where efficacy is maximized and toxicities minimized. This review focuses on one of the most established cellular therapies, hematopoietic stem cell transplant, and one of the newest cellular therapies, chimeric antigen receptor-T cells. In this review, I will discuss the current state of the field for clinical end point analysis with each of these therapeutics, including their critical toxicities, and focus on the major elements of success for each of these complex treatments for hematologic disease.

Tumor Necrosis Factor α and Regulatory T Cells in Oncoimmunology

Tumor necrosis factor α (TNF) is a potent pro-inflammatory cytokine that has deleterious effect in some autoimmune diseases, which led to the use of anti-TNF drugs in some of these diseases. However, some rare patients treated with these drugs paradoxically develop an aggravation of their disease or new onset autoimmunity, revealing an immunosuppressive facet of TNF. A possible mechanism of this observation is the direct and positive effect of TNF on regulatory T cells (Tregs) through its binding to the TNF receptor type 2 (TNFR2). Indeed, TNF is able to increase expansion, stability, and possibly function of Tregs via TNFR2. In this review, we discuss the role of TNF in graft-versus-host disease as an example of the ambivalence of this cytokine in the pathophysiology of an immunopathology, highlighting the therapeutic potential of triggering TNFR2 to boost Treg expansion. We also describe new targets in immunotherapy of cancer, emphasizing on the putative suppressive effect of TNF in antitumor immunity and of the interest of blocking TNFR2 to regulate the Treg compartment.

Association between single nucleotide polymorphisms of tumor necrosis factor gene and grade II-IV acute GvHD: a systematic review and meta-analysis

Acute GvHD (aGvHD) complicates up to 50% of allogeneic hematopoietic cell transplants and pre-transplant estimation of its risk can guide prophylaxis, monitoring and early intervention strategies. Inspired by the role of tumor necrosis factor alpha (TNFα) in the pathogenesis of aGvHD and the inconsistency of the association studies exploring single nucleotide polymorphisms (SNPs) of the TNF gene, we conducted a systematic review and meta-analysis of the available reports using PubMed and EMBASE. Original human studies reporting on the association between recipient TNF SNPs and grade II-IV aGvHD in a format convertible to effect size and confidence interval were included. One of the two most widely investigated SNPs (rs361525G>A) was marginally associated with increased risk of grade II-IV aGvHD in random-effects meta-analysis of six studies (627 patients in total, risk ratio=1.29, 95% confidence interval=0.99-1.69, P=0.06). If this result is validated in a large cohort with uniform conditioning and GvHD prophylaxis, TNF rs361525G>A may become a useful tool for aGvHD risk estimation before the transplant.

Composite biomarker panel for prediction of severity and diagnosis of acute GVHD with T-cell-depleted allogeneic stem cell transplants-single centre pilot study

AIMS

Acute graft-versus-host disease (aGVHD) is a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate the clinical utility of a composite biomarker panel to help identify individuals at risk of developing aGVHD, and to help predict and differentiate between severity of aGVHD following T-cell-depleted allogeneic HSCT.

METHODS

We retrospectively analysed our cohort of biopsy confirmed patients with aGVHD, who underwent T-cell-depleted HSCT and matched them with negative controls without any evidence of aGVHD. Post-transplant serum samples on days 0 and 7 and at onset of aGVHD were analysed for elafin, regenerating islet-derived 3-α, soluble tumour necrosis factor receptor-1, soluble interleukin-2 receptor-α and hepatocyte growth factor. Biomarker data were combined as composite panels A-F (table 2) using logistic regression analysis. Receiver operating characteristic analysis was performed to study sensitivity and specificity of the composite panels.

RESULTS

Our composite biomarker panels significantly differentiated between aGVHD and no GVHD patients at time of onset (panel E) and reliably predicted severity of GVHD grades at days 0 and 7 post-transplant (panels B and D). The area under the curve for the composite panel at time of onset was 0.65 with specificity, sensitivity, positive and negative predictive values of 100%, 55.6%, 100% and 78.9%, respectively (p=0.03).

CONCLUSIONS

This pilot data support the usefulness of these composite biomarker panels in the prediction of severity and diagnosis of aGVHD in patients undergoing T-cell-depleted reduced intensity allogeneic HSCT.

Plasma-derived proteomic biomarkers in human leukocyte antigen-haploidentical or human leukocyte antigen-matched bone marrow transplantation using post-transplantation cyclophosphamide

Recent studies have suggested that plasma-derived proteins may be potential biomarkers relevant for graft-versus-host disease and/or non-relapse mortality occurring after allogeneic blood or marrow transplantation. However, none of these putative biomarkers have been assessed in patients treated either with human leukocyte antigen-haploidentical blood or marrow transplantation or with post-transplantation cyclophosphamide, which has been repeatedly associated with low rates of severe acute graft-versus-host disease, chronic graft-versus-host disease, and non-relapse mortality. We explored whether seven of these plasma-derived proteins, as measured by enzyme-linked immunosorbent assays, were predictive of clinical outcomes in post-transplantation cyclophosphamide-treated patients using plasma samples collected at serial predetermined timepoints from patients treated on prospective clinical studies of human leukocyte antigen-haploidentical (n=58; clinicaltrials.gov Identifier: 00796562) or human leukocyte antigen-matched-related or -unrelated (n=100; clinicaltrials.gov Identifiers: 00134017 and 00809276) T-cell-replete bone marrow transplantation. Day 30 levels of interleukin-2 receptor α, tumor necrosis factor receptor 1, serum STimulation-2 (IL1RL1 gene product), and regenerating islet-derived 3-α all had high areas under the curve of 0.74–0.97 for predicting non-relapse mortality occurrence by 3 months post-transplant in both the human leukocyte antigen-matched and human leukocyte antigen-haploidentical cohorts. In both cohorts, all four of these proteins were also predictive of subsequent non-relapse mortality occurring by 6, 9, or 12 months post-transplant and were significantly associated with non-relapse mortality in univariable analyses. Furthermore, day 30 elevations of interleukin-2 receptor α were associated with grade II–IV and III–IV acute graft-versus-host disease occurring after day 30 in both cohorts. These data confirm that plasma-derived proteins previously assessed in other transplantation platforms appear to retain prognostic and predictive utility in patients treated with post-transplantation cyclophosphamide.

The Role of Biomarkers in the Diagnosis and Risk Stratification of Acute Graft-versus-Host Disease: A Systematic Review

Allogeneic hematopoietic cell transplantation (HCT) is an increasingly used curative modality for hematologic malignancies and other benign conditions. Attempts to reduce morbidity and mortality and improve survival in patients undergoing HCT are crucial. The ability to diagnose acute graft-versus-host disease (aGVHD) in a timely manner, or to even predict aGVHD before clinical manifestations, along with the accurate stratification of these patients, are critical steps to improve the treatment and outcomes of these patients. Many novel biomarkers that may help achieve these goals have been studied recently. This overview is intended to assist clinicians and investigators by providing a comprehensive review and analytical interpretation of the current knowledge concerning aGVHD and biomarkers likely to prove useful in diagnosis and risk stratification of this condition, along with the difficulties that hamper this approach.

Combination Therapy for Graft-versus-Host Disease Prophylaxis with Etanercept and Extracorporeal Photopheresis: Results of a Phase II Clinical Trial

Reduced-intensity conditioning (RIC) regimens minimize early toxicity after allogeneic hematopoietic cell transplantation (HCT) by placing greater reliance on establishing a graft-versus-leukemia effect (GVL). Because graft-versus-host disease (GVHD) and GVL are tightly linked, inhibition of T cell populations that cause GVHD may lead to an unintended increased risk of relapse in the RIC setting. Although not completely understood, etanercept and extracorporeal photopheresis (ECP) are thought to ameliorate GVHD without direct T cell inhibition. We hypothesized that adding these 2 agents to a standard GVHD prophylaxis regimen of tacrolimus and mycophenolate mofetil (MMF) would improve survival by reducing GVHD-related mortality without increasing relapse rates. Therefore, we conducted a prospective phase II clinical trial that incorporated tacrolimus, MMF, etanercept, and ECP as GVHD prophylaxis in 48 patients undergoing RIC unrelated donor transplantation. The preferred RIC was fludarabine 160 mg/m(2) + busulfan 6.4 mg/kg to 12.8 mg/kg ± total body irradiation 200 cGy. Etanercept .4 mg/kg (maximum dose, 25 mg) was given subcutaneously twice weekly for 8 weeks after HCT and ECP was given for 12 treatments, starting weekly on day 28 weekly and tapering off by day 180. The median age of the study patients was 60 (range, 18 to 71) years. Donors were 7/8 (n = 14, 29%) or 8/8 (n = 34, 71%) HLA matched. All patients engrafted neutrophils at a median of 12 days. The cumulative incidence of grades II to IV acute GVHD at day 100 was 46%, but it was typically sensitive to initial steroid treatment (84% day 56 complete response/partial response rate). Overall survival at 1 year in this older, frequently mismatched unrelated donor setting was excellent (73%) because of low rates of nonrelapse mortality (21%) and relapse (19%). However, this strategy was not effective at preventing a high incidence of chronic GVHD and late deaths led to a drop in 2-year survival, declining to 56%, reflecting a high incidence of chronic GVHD.

Peripheral Blood CD38 Bright CD8+ Effector Memory T Cells Predict Acute Graft-versus-Host Disease

Acute graft-versus-host disease (aGVHD) is mediated by allogeneic T cell responses. We hypothesized that increases of peripheral blood-activated CD8+ effector memory T (TEM) cells would be observed after hematopoietic stem cell transplantation (HSCT) before onset of aGVHD symptoms. Blood was collected twice weekly after HSCT for 7 weeks in 49 consecutive pediatric and adult HSCT recipients. Samples were incubated with fluorochrome-conjugated antibodies against CD45, CD3, CD8, CD38, CD45RA, and CCR7 and analyzed using flow cytometry. TEM cells were defined as CD3+ CD8+ CCR7- CD45RA(-) lymphocytes. CD38 expression was used as a marker of T cell activation. Patients were followed for 100 days for development of aGVHD. Twenty-three patients developed grade 1 to 4 aGVHD at a median of 37 days (range, 15 to 79 days) after HCST. Absolute CD38 bright CD8+ TEM of > 35 cells/μL predicted aGVHD at a median of 8 days (range, 1 to 34) before aGVHD onset with a sensitivity of 82.6% and specificity of 91.6%. The cumulative incidence of aGVHD was 90% in patients with absolute CD38 bright CD8+ TEM >35 cells/μL and 15% in patients without (P < .0001). Quantification of CD38 bright CD8+ TEM cells may predict aGVHD in children and young adult HSCT recipients.

Etanercept plus topical corticosteroids as initial therapy for grade one acute graft-versus-host disease after allogeneic hematopoietic cell transplantation

Clinical diagnosis of grade 1 acute graft-versus-host disease (GVHD) marks the beginning of a potentially progressive and fatal course of GVHD after hematopoietic stem cell transplantation (HSCT). However, interventional studies to treat early GVHD are lacking. We conducted a single-arm prospective phase II trial to test the hypothesis that treatment of newly diagnosed grade 1 acute GVHD with etanercept and topical corticosteroids would reduce progression to grade 2 to 4 within 28 days. Study patients (n = 34) had a median age of 51 years (range, 10 to 67 years) and had undergone unrelated (n = 22) or related (n = 12) donor HSCT. Study patients were treated with etanercept (.4 mg/kg, maximum 25 mg/dose) twice weekly for 4 to 8 weeks. Ten of 34 patients (29%) progressed to grade 2 to 4 acute GVHD within 28 days. The cumulative incidence of grade 2 to 4 and grade 3 to 4 acute GVHD at 1 year was 41% and 3%, respectively. Nonrelapse mortality was 19% and overall survival was 63% at 2 years. Among a contemporaneous control cohort of patients who were diagnosed with grade 1 acute GVHD and treated with topical corticosteroids but not etanercept during the study period, 12 of 28 patients (43%) progressed to grade 2 to 4 GVHD within 28 days, with a 1-year incidence of grade 2 to 4 GVHD and grade 3 to 4 GVHD of 61% (41% versus 61%, P = .08) and 18% (3% versus 18%, P = .05), respectively. Patients treated with etanercept also experienced less increase in GVHD plasma biomarkers suppression of tumorigenicity 2 (P = .06) and regenerating islet-derived 3-alpha (P = .01) 28 days after grade 1 acute GVHD diagnosis compared with contemporaneous control patients. This study was terminated early because of poor accrual. Future prospective studies are needed to identify patients with grade 1 acute GVHD at risk of swift progression to more severe GVHD and to establish consensus for the treatment of grade 1 acute GVHD. This trial is registered with ClinicalTrials.gov, number NCT00726375.

Potential biomarkers for early detection of acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is the main complication of allogeneic hematopoietic stem cell transplantation (HCT), resulting in considerable morbidity and mortality. Currently, the diagnosis of aGVHD is largely made based on clinical parameters and invasive biopsies. For the past 20 years, researchers have been trying to find reliable biomarkers to enable early and accurate diagnosis of aGVHD. Although a number of potential aGVHD biomarkers have been published, as yet, no validated diagnostic test is available. Proteomics encompasses a broad range of rapidly developing technologies, which have shown tremendous promise for early detection of aGVHD. In this article, we review the current state of aGVHD biomarker discovery, provide a summary of the key proteins of interest and the most common analytical procedures for the clinic, as well as outlining the significant challenges faced in their use.

Advances in predicting acute GVHD

Acute graft-versus-host disease (GVHD) is a leading cause of non-relapse mortality following allogeneic haematopoietic cell transplantation. Attempts to improve treatment response in clinically-established GVHD have not improved overall survival, often due to the increased risk of infectious complications. Alternative approaches to decrease GVHD-related morbidity and mortality have focused on the ability to predict GVHD prior to clinical manifestation in an effort to provide an opportunity to abort GVHD development, and to gain new insights into GVHD pathophysiology. This review outlines the research efforts to date that have identified clinical and laboratory-based factors that are predictive of acute GVHD and describes future directions in developing algorithms that will improve the ability to predict the development of clinically relevant GVHD.

Mesenchymal stromal cells: a new tool against graft-versus-host disease?

Mesenchymal stromal cells (MSCs) represent a heterogeneous subset of multipotent cells that can be isolated from several tissues including bone marrow and fat. MSCs exhibit immunomodulatory and anti-inflammatory properties that prompted their clinical use as prevention and/or treatment for severe graft-versus-host disease (GVHD). Although a number of phase I-II studies have suggested that MSC infusion was safe and might be effective for preventing or treating acute GVHD, definitive proof of their efficacy remains lacking thus far. Multicenter randomized studies are ongoing to more precisely assess the impact of MSC infusion on GVHD prevention/treatment, whereas further research is performed in vitro and in animal models with the aims of determining the best way to expand MSCs ex vivo as well as the most efficient dose and schedule of MSCs administration. After introducing GVHD, MSC biology, and results of MSC infusion in animal models of allogeneic hematopoietic cell transplantation, this article reviews the results of the first clinical trials investigating the use of MSC infusion as prevention or treatment of GVHD.

Acute renal endothelial injury during marrow recovery in a cohort of combined kidney and bone marrow allografts

An idiopathic capillary leak syndrome ('engraftment syndrome') often occurs in recipients of hematopoietic cells, manifested clinically by transient azotemia and sometimes fever and fluid retention. Here, we report the renal pathology in 10 recipients of combined bone marrow and kidney allografts. Nine developed graft dysfunction on day 10-16 and renal biopsies showed marked acute tubular injury, with interstitial edema, hemorrhage and capillary congestion, with little or no interstitial infiltrate (≤10%) and marked glomerular and peritubular capillary (PTC) endothelial injury and loss by electron microscopy. Two had transient arterial endothelial inflammation; and 2 had C4d deposition. The cells in capillaries were primarily CD68(+) MPO(+) mononuclear cells and CD3(+) CD8(+) T cells, the latter with a high proliferative index (Ki67(+) ). B cells (CD20(+) ) and CD4(+) T cells were not detectable, and NK cells were rare. XY FISH showed that CD45(+) cells in PTCs were of recipient origin. Optimal treatment remains to be defined; two recovered without additional therapy, six were treated with anti-rejection regimens. Except for one patient, who later developed thrombotic microangiopathy and one with acute humoral rejection, all fully recovered within 2-4 weeks. Graft endothelium is the primary target of this process, attributable to as yet obscure mechanisms, arising during leukocyte recovery.

Implications of TNF-α in the pathogenesis and management of GVHD

Clinical graft-versus-host disease (GVHD) symptoms are the result of a complex set of interactions between cellular and soluble factors. One of the key soluble factors is the proinflammatory cytokine, TNF-α, which participates in the initiating events that culminate in GVHD as well as amplifies the disease process once established. The importance of TNF-α in this process has been supported by a series of clinical experiments demonstrating strong correlation between TNF receptor-1 levels and GVHD. TNF-α has both indirect effects, through activating and proliferation pathways of T cells, the main cellular effector of GVHD, and direct effects leading to apoptosis, on GVHD target tissues. Accordingly, TNF-α has been used as a therapeutic target in experimental GVHD prevention and treatment strategies with promising clinical results. TNF-α can be pharmacologically inhibited using soluble TNF receptors or monoclonal antibodies. The optimal dosing and duration of TNF inhibition to prevent or treat GVHD remains under investigation.

Early elevation of C-reactive protein correlates with severe infection and nonrelapse mortality in children undergoing allogeneic stem cell transplantation

C-reactive protein (CRP) is an acute phase reactant that is a reliable marker of systemic inflammation and has been associated with increased morbidity and mortality following hematopoietic stem cell transplantation (HSCT) in adults. In this study, we evaluated whether early elevations of CRP were associated with various complications and nonrelapse mortality following HSCT in pediatric patients. Seventy pediatric patients had CRP levels drawn at regular time points during the first week following their transplants. Patients were followed for 100 days following transplant, and transplant-related complications were documented. Patients who subsequently developed severe infections had higher median CRP values than those without severe infections (median 8.03 mg/dL versus 1.64 mg/dL, P = .0008) as did those who suffered nonrelapse mortality compared with those who did not (12.6 mg/dL versus 2.44 mg/dL, P = .02). These findings suggest that elevated CRP values may be useful as a marker of individual pediatric patients with a higher risk for treatment-related morbidity and mortality.

Elevations of tumor necrosis factor receptor 1 at day 7 and acute graft-versus-host disease after allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning

Acute GVHD has remained a significant cause of nonrelapse mortality after allogeneic hematopoietic cell transplantation (HCT) with nonmyeloablative conditioning. The role of TNF-alpha in the biology of acute GVHD after nonmyeloablative conditioning has not been studied thus far. Here, we measured TNF receptor 1 (TNFR1) as a surrogate marker for TNF-alpha in 106 patients before the start of the conditioning regimen (baseline) and 7 days after allogeneic HCT with nonmyeloablative conditioning. The nonmyeloablative regimen consisted of 2 Gy TBI alone (n=15), 2 Gy TBI plus fludarabine 90 mg/m2 (n=73), or 4 Gy TBI plus fludarabine 90 mg/m2 (n=18). TNFR1 levels increased significantly from baseline to day 7 after nonmyeloablative HCT (P<0.0001). Patients conditioned with 4 Gy TBI had higher TNFR1 day 7/baseline ratio than those conditioned with 2 Gy TBI (median 1.65 versus 1.25; P=0.01). In a multivariate Cox model, high TNFR1 day7/baseline ratio was associated with grades II-IV (HR=2.2, P=0.01) and grades III-IV (HR=2.9, P=0.007) acute GVHD, but had no impact on overall survival (P=0.8). In summary, our data suggest that nonmyeloablative conditioning induces the generation of TNF-alpha, and that the magnitude of TNF-alpha generation depends on the conditioning intensity (2 Gy versus 4 Gy TBI). Further, assessment of TNFR1 levels before and on day 7 after nonmyeloablative HCT provided useful information on subsequent risk of experiencing acute GVHD.