The IL-33/ST2 axis augments effector T-cell responses during acute GVHD. Blood. 2015;125:3183-3192. [PMID: 25814531 DOI: 10.1182/blood-2014-10-606830]

The Biological Context of C-Reactive Protein as a Prognostic Marker in Renal Cell Carcinoma: Studies on the Acute Phase Cytokine Profile

High serum levels of the acute phase protein C-reactive protein (CRP) are associated with an adverse prognosis in renal cancer. The acute phase reaction is cytokine-driven and includes a wide range of inflammatory mediators. This overall profile of the response depends on the inducing event and can also differ between patients. We investigated an extended acute phase cytokine profile for 97 renal cancer patients. Initial studies showed that the serum CRP levels had an expected prognostic association together with tumor size, stage, nuclear grading, and Leibovich score. Interleukin (IL)6 family cytokines, IL1 subfamily mediators, and tumor necrosis factor (TNF)α can all be drivers of the acute phase response. Initial studies suggested that serum IL33Rα (the soluble IL33 receptor α chain) levels were also associated with prognosis, although the impact of IL33Rα is dependent on the overall cytokine profile, including seven IL6 family members (IL6, IL6Rα, gp130, IL27, IL31, CNTF, and OSM), two IL1 subfamily members (IL1RA and IL33Rα), and TNFα. We identified a patient subset characterized by particularly high levels of IL6, IL33Rα, and TNFα alongside an adverse prognosis. Thus, the acute phase cytokine reaction differs between renal cancer patients, and differences in the acute phase cytokine profile are associated with prognosis.

Macrophage regulation of graft-vs-host disease

Hematopoietic stem cell transplantation has become a curative choice of many hematopoietic malignancy, but graft-vs-host disease (GVHD) has limited the survival quality and overall survival of hematopoietic stem cell transplantation. Understanding of the immune cells’ reaction in pathophysiology of GVHD has improved, but a review on the role of macrophages in GVHD is still absent. Studies have observed that macrophage infiltration is associated with GVHD occurrence and development. In this review, we summarize and analyze the role of macrophages in GVHD based on pathophysiology of acute and chronic GVHD, focusing on the macrophage recruitment and infiltration, macrophage polarization, macrophage secretion, and especially interaction of macrophages with other immune cells. We could conclude that macrophage recruitment and infiltration contribute to both acute and chronic GVHD. Based on distinguishing pathology of acute and chronic GVHD, macrophages tend to show a higher M1/M2 ratio in acute GVHD and a lower M1/M2 ratio in chronic GVHD. However, the influence of dominant cytokines in GVHD is controversial and inconsistent with macrophage polarization. In addition, interaction of macrophages with alloreactive T cells plays an important role in acute GVHD. Meanwhile, the interaction among macrophages, B cells, fibroblasts, and CD4+ T cells participates in chronic GVHD development.

Predicting Immuno-Metabolic Complications After Allogeneic Hematopoietic Cell Transplant with the Cytokine Interleukin-33 (IL-33) and its Receptor Serum-Stimulation 2 (ST2)

Patients undergoing allogeneic hematopoietic cell transplantation (HCT) are at risk for numerous acute and long-term complications from this procedure. Post-transplant diabetes mellitus (PTDM) is a common but under-recognized problem. Similar to graft-versus-host disease (GVHD), new-onset diabetes is characterized by immune dysregulation that can negatively impact transplant outcomes. This review will discuss the biology of IL-33/ST2 in acute GVHD and PTDM development, and how this cytokine axis could be leveraged for predicting and treating immuno-metabolic complications after transplant.

Predictive Values of Early Suppression of Tumorigenicity 2 for Acute GVHD and Transplant-related Complications after Allogeneic Stem Cell Transplantation: Prospective Observational Study

Objective

A soluble form of suppression of tumorigenicity 2 (sST2) has emerged as a biomarker for acute graft-versus-host disease (GVHD) and non-relapse mortality (NRM). We prospectively monitored sST2 levels during the early phase of hematopoietic stem cell transplantation (HSCT) and evaluated the clinical association with transplant-related complications including acute GVHD.

Materials and Methods

Thirty-two adult Japanese patients who received a first allogeneic HSCT were enrolled in this study. Levels of sST2 were measured at fixed time points (pre-conditioning, day 0, day 14, day 21, and day 28).

Results

The median age was 50.5 years (range=16-66). With a median follow-up of 21.5 months (range=0.9-35.4), 9 patients developed grade II-IV acute GVHD. Median sST2 levels on the day of HSCT were higher than baseline and reached the maximum value (92.7 ng/mL; range=0-419.7) on day 21 after HSCT. The optimal cut-off value of sST2 on day 14 for predicting grade II-IV acute GVHD was determined as 100 ng/mL by ROC analysis. The cumulative incidence of acute GVHD was 56.7% and 16.5% in the high- and low-sST2 groups, respectively (p<0.01). Multivariate analyses showed that high sST2 levels at day 14 were associated with a higher incidence of acute GVHD (hazard ratio=9.35, 95% confidence interval=2.92-30.0, p<0.01). The cumulative incidence of NRM was increased in the highs-ST2 group (33% vs 0%, p<0.01), but all the patients died of non-GVHD complications. Among 6 patients in the high-sST2 group without grade II-IV GVHD, 5 patients developed veno-occlusive disease (VOD) and one also had thrombotic microangiopathy (TMA).

Conclusion

The early assessment of sST2 after HSCT yielded predictive values for the onset of acute GVHD and other transplant-related complications including VOD and TMA.

Association of plasma-soluble ST2 and galectin-3 with cardiovascular events and mortality following cardiac surgery

BACKGROUND

Cardiac surgery induces hemodynamic stress on the myocardium, and this process can be associated with significant post-operative morbidity and mortality. Soluble suppression of tumorigenicity 2 (sST2) and galectin-3 (gal-3) are biomarkers of myocardial remodeling and fibrosis; however, their potential association with post-operative changes is unknown.

METHODS

We measured peri-operative plasma sST2 and gal-3 levels in two prospective cohorts (TRIBE-AKI and NNE) of over 1800 patients who underwent cardiac surgery. sST2 and gal-3 levels were evaluated for association with a composite primary outcome of cardiovascular event or mortality over median follow-up periods of 3.4 and 6.0 years, respectively, for the two cohorts. Meta-analysis of hazard ratio estimates from the cohorts was performed using random effects models.

RESULTS

Cohorts demonstrated event rates of 70.2 and 66.8 per 1000 person-years for the primary composite outcome. After adjustment for clinical covariates, higher post-operative sST2 and gal-3 levels were significantly associated with cardiovascular event or mortality [pooled estimate HRs: sST2 1.29 (95% CI 1.16, 1.44); gal-3 1.26 (95% CI 1.09, 1.46)]. These associations were not significantly modified by pre-operative congestive heart failure or AKI.

CONCLUSIONS

Higher post-operative sST2 and gal-3 values were associated with increased incidence of cardiovascular event or mortality. These two biomarkers should be further studied for potential clinical utility for patients undergoing cardiac surgery.

Biomarkers in acute graft-versus-host disease: new insights

Hematopoietic cell transplantation (HCT) is a potentially curative therapy for hematologic malignancies that relies on the graft-versus-leukemia (GVL) effect to eradicate malignant cells. GVL is tightly linked to graft-versus-host disease (GVHD) however, in which donor T cells damage healthy host tissues. Acute GVHD occurs in nearly 50% of patients receiving HCT, and damages the skin, liver, and gastrointestinal (GI) tract. The organ stages are totaled in an overall grade (I-IV), and severe (grade III/IV) GVHD has a high mortality rate (50-70%). In the past decade, serum biomarkers have emerged as an additional potential measurement of acute GVHD severity. The discovery and validation of GVHD biomarkers is a principal objective of the Mount Sinai Acute GVHD International Consortium (MAGIC), a group of 25 HCT centers conducting GVHD research. MAGIC has validated an algorithm that combines two GI biomarkers (ST2 and REG3α) into a single value that estimates the probability of 6 month nonrelapse mortality (NRM) for individual patients, known as the MAGIC algorithm probability (MAP). The MAP reflects GI crypt damage and serves as a 'liquid biopsy' of the lower GI tract; it also predicts response to treatment and maximum GVHD severity and is now commercially available and widely used among scores of centers in clinical practice. The MAP is the focus of this review, with consideration of the categorization of types of biomarkers as defined by the United States National Institutes of Health (NIH) and Food and Drug Administration (FDA).

Loss of Lkb1 impairs Treg function and stability to aggravate graft-versus-host disease after bone marrow transplantation

Accumulating evidence suggests that a reduction in the number of Foxp3⁺ regulatory T cells (Tregs) contributes to the pathogenesis of acute graft-versus-host disease (aGVHD), which is a major adverse complication that can occur after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the precise features and mechanism underlying the defects in Tregs remain largely unknown. In this study, we demonstrated that Tregs were more dramatically decreased in bone marrow compared with those in peripheral blood from aGVHD patients and that bone marrow Treg defects were negatively associated with hematopoietic reconstitution. Tregs from aGVHD patients exhibited multiple defects, including the instability of Foxp3 expression, especially in response to IL-12, impaired suppressor function, decreased migratory capacity, and increased apoptosis. Transcriptional profiling revealed the downregulation of Lkb1, a previously identified critical regulator of murine Treg identity and metabolism, and murine Lkb1-regulated genes in Tregs from aGVHD patients. Foxp3 expression in human Tregs could be decreased and increased by the knockdown and overexpression of the Lkb1 gene, respectively. Furthermore, a loss-of-function assay in an aGVHD murine model confirmed that Lkb1 deficiency could impair Tregs and aggravate disease severity. These findings reveal that Lkb1 downregulation contributes to multiple defects in Tregs in human aGVHD and highlight the Lkb1-related pathways that could serve as therapeutic targets that may potentially be manipulated to mitigate aGVHD.

MAGIC biomarkers of acute graft-versus-host disease: Biology and clinical application

Acute graft-versus-host disease (GVHD) is the major complication of allogeneic hematopoietic cell transplantation and is the primary cause of early non-relapse mortality (NRM) after transplant. GVHD of the gastrointestinal (GI) tract fuels the systemic inflammatory reaction and consequently is the principal driver of mortality. Recently, the MAGIC algorithm probability (MAP) that is computed from two biomarkers of GI GVHD has been validated to accurately predict risk of NRM throughout the course of early acute GVHD. This review focuses on the biology, clinical evidence, and practical application of the biomarkers in the measurement of acute GVHD.

ILC2 Activation by Protozoan Commensal Microbes

Group 2 innate lymphoid cells (ILC2s) are a member of the ILC family and are involved in protective and pathogenic type 2 responses. Recent research has highlighted their involvement in modulating tissue and immune homeostasis during health and disease and has uncovered critical signaling circuits. While interactions of ILC2s with the bacterial microbiome are rather sparse, other microbial members of our microbiome, including helminths and protozoans, reveal new and exciting mechanisms of tissue regulation by ILC2s. Here we summarize the current field on ILC2 activation by the tissue and immune environment and highlight particularly new intriguing pathways of ILC2 regulation by protozoan commensals in the intestinal tract.

GVHD: biology matters

Acute graft-versus-host disease (GVHD) targets the crypts in the gastrointestinal (GI) tract that are responsible for the self-renewal of the intestinal mucosa. Recent advances in the identification and culture of intestinal stem cells have improved our understanding of the interactions between the microbiome and the immune system (both innate and adaptive) that are key to the pathophysiology of GVHD. The identification of serum biomarkers that best predict long-term GVHD outcomes derive from the GI tract and have focused attention on cellular elements that act as shields against GVHD as well as its targets. These biomarkers have illuminated new mechanisms of crypt biology and provided insights that should prove useful both in the design of clinical trials and as guides to GVHD prevention and treatment.

The promise of CD4+FoxP3+ regulatory T-cell manipulation in vivo: applications for allogeneic hematopoietic stem cell transplantation

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.

The roles of nuclear focal adhesion kinase (FAK) on Cancer: a focused review

FAK is a tyrosine kinase overexpressed in cancer cells and plays an important role in the progression of tumors to a malignant phenotype. Except for its typical role as a cytoplasmic kinase downstream of integrin and growth factor receptor signaling, related studies have shown new aspects of the roles of FAK in the nucleus. FAK can promote p53 degradation through ubiquitination, leading to cancer cell growth and proliferation. FAK can also regulate GATA4 and IL-33 expression, resulting in reduced inflammatory responses and immune escape. These findings establish a new model of FAK from the cytoplasm to the nucleus. Activated FAK binds to transcription factors and regulates gene expression. Inactive FAK synergizes with different E3 ligases to promote the turnover of transcription factors by enhancing ubiquitination. In the tumor microenvironment, nuclear FAK can regulate the formation of new blood vessels, affecting the tumor blood supply. This article reviews the roles of nuclear FAK in regulating gene expression. In addition, the use of FAK inhibitors to target nuclear FAK functions will also be emphasized.

ST2 and the ST2/IL-33 signalling pathway-biochemistry and pathophysiology in animal models and humans

ST2 is an interleukin (IL)-1 receptor family member with transmembrane (ST2L) and soluble (sST2) isoforms. Structurally, the ST2 gene products are very similar in mice and humans. In humans and in mice, alternative promoter activation and splicing produce ST2L and sST2. ST2L represents the longest transcript, whereas sST2 is the truncated, soluble isoform. ST2L is the biological receptor for IL-33, a member of the IL-1 family. IL-33 is the functional ligand of ST2L and signals the presence of tissue damage to local immune cells. IL-33/ST2L signalling leads to the production of inflammatory cytokines/chemokines and to the induction of the immune response. Conversely, sST2 functions as a decoy receptor for IL-33, inhibiting the effects of IL-33/ST2L signalling. Animal studies have allowed the investigation of ST2 and the IL-33/ST2L signalling pathway at multiple levels. However, clinical studies have mainly focused on the determination of sST2 in the circulation. In humans, plasma concentrations of sST2 increase in several diseases, such as heart disease, pulmonary disease, burn injury and graft-versus-host disease. Consequently, increased plasma concentrations of sST2 are not specific for a single disorder in humans and are thus of limited value for diagnostic purposes. However, increased plasma concentrations of sST2 have been linked to a worse prognosis in numerous diseases. Nevertheless, the major source of circulating sST2 in healthy and diseased humans is currently not fully established. In addition, whether the downregulation of sST2 can improve the outcome of patients in the clinical setting has not been elucidated. The aim of the present review was to provide an update on the findings regarding the biochemistry and pathophysiology of ST2 and the sST2 signalling pathway in humans and experimental models.

ST2/MyD88 Deficiency Protects Mice against Acute Graft-versus-Host Disease and Spares Regulatory T Cells

Acute graft-versus-host disease (aGVHD) hinders the efficacy of allogeneic hematopoietic cell transplantation (HCT). Plasma levels of soluble membrane-bound ST2 (ST2) are elevated in human and murine aGVHD and correlated to type 1 T cells response. ST2 signals through the adapter protein MyD88. The role of MyD88 in T cells during aGVHD has yet to be elucidated. We found that knocking out MyD88 in the donor T cells protected against aGVHD independent of IL-1R and TLR4 signaling in two murine HCT models. This protection was entirely driven by MyD88^-/- CD4 T cells. Transplanting donor MyD88^-/- conventional T cells (Tcons) with wild-type (WT) or MyD88^-/- regulatory T cells (Tregs) lowered aGVHD severity and mortality. Transcriptome analysis of sorted MyD88^-/- CD4 T cells from the intestine 10 d post-HCT showed lower levels of Il1rl1 (gene of ST2), Ifng, Csf2, Stat5, Batf, and Jak2 Transplanting donor ST2^-/- Tcons with WT or ST2^-/- Tregs showed a similar phenotype with what we observed when using donor MyD88^-/- Tcons. Decreased ST2 was confirmed at the protein level with less secretion of soluble ST2 and more expression of ST2 compared with WT T cells. Our data suggest that Treg suppression from lack of MyD88 signaling in donor Tcons during alloreactivity uses the ST2 but not the IL-1R or TLR4 pathways, and ST2 represents a potential aGVHD therapeutic target sparing Tregs.

IL-33/ST2 Axis Regulates Vasculogenic Mimicry via ERK1/2-MMP-2/9 Pathway in Melanoma

BACKGROUND

Melanoma, an extremely malignant form of cancer, poses a significant health risk. Vasculogenic mimicry (VM), blood vessels formed by tumor cells instead of endothelial cells, is an important factor for the rapid progression of melanoma. Interleukin (IL)-33 is an inflammatory factor commonly found in the tumor microenvironment and plays an important role in the progression of many tumors. IL-33 acts on immune cells and tumor cells through its receptor ST2. This study hypothesized that IL-33 directly affects the progression of melanoma.

OBJECTIVES

This study was designed to investigate the effect of IL-33 on VM of melanoma and its potential mechanism of action.

METHODS

The expression of ST2 was evaluated in 66 cases of melanoma collected from human patients, and the differences were analyzed. In vitro experiments were conducted to study the effects of the IL-33/ST2 axis on cell migration and invasion and to elucidate possible mechanisms.

RESULTS

ST2 expression is associated with that of matrix metalloproteinase (MMP)-2 and VM in melanoma of patients. IL-33 increases the abilities of proliferation, migration and invasion of melanoma cells and VM tube formation through ST2. IL-33 induces the production of MMP-2/9 via ERK1/2 phosphorylation.

CONCLUSION

IL-33 can directly act on melanoma cells and promote its development.

Inflammatory Cytokine Networks in Gastrointestinal Tract Graft vs. Host Disease

Graft vs. host disease (GVHD) is the major non-relapse complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). Damage to the gastrointestinal (GI) tract from acute GVHD is a particularly serious event that can result in significant morbidity and mortality. Proinflammatory cytokines play a critical role in the pathophysiology of intestinal GVHD, in part by activating donor T cell populations which subsequently induce tissue damage. In this review, we summarize pre-clinical data derived from experimental murine models that have examined the role of inflammatory cytokine pathways that play critical roles in the pathophysiology of GVHD of the GI tract. Specific areas of focus are on STAT 3-dependent cytokines (e.g., IL-6, IL-23, and IL-21), and members of the IL-1 cytokine family, both of which have been shown to induce pathological damage within the GI tract during this disease. We also review established and ongoing efforts to translate these pre-clinical findings into the clinic in an effort to reduce morbidity and mortality due to this complication.

Mast cells are essential intermediaries in regulating IL-33/ST2 signaling for an immune network favorable to mucosal healing in experimentally inflamed colons

Mast cells (MCs) are potent tissue-resident immune cells that are distributed in the intraepithelial space of the intestine and have been implicated in regulating immune homeostasis and coordinating epithelial responses in inflamed mucosa of inflammatory bowel disease (IBD). IL-33 functions as an endogenous danger signal or alarmin in inflamed intestine segments. MCs highly express the IL-33 receptor ST2. However, the mechanisms underlying the immune regulation of MC-dependent IL-33/ST2 signaling at the barrier surface of the intestine remain largely unknown. We confirmed that MCs are required for the effective resolution of tissue damage using an experimental colitis model that allows for conditional ablation of MCs. After elucidating the IL-33 signaling involved in MC activity in the context of intestinal inflammation, we found that the function of restricted IL-33/ST2 signaling by MCs was consistent with an MC deficiency in response to the breakdown of the epithelial barrier. We observed that a tissue environment with a spectrum of protective cytokines was orchestrated by MC-dependent IL-33/ST2 signaling. Given the significant downregulation of IL-22 and IL-13 due to the loss of MC-dependent IL-33/ST2 signaling and their protective functions in inflammation settings, induction of IL-22 and IL-13 may be responsible for an immune network favorable to mucosal repair. Collectively, our data showed an important feedback loop in which cytokine cues from damaged epithelia activate MCs to regulate tissue environments essential for MC-dependent restoration of epithelial barrier function and maintenance of tissue homeostasis.

Increased Expression of sST2 in Early HIV Infected Patients Attenuated the IL-33 Induced T Cell Responses

T cell responses were less functional and persisted in an exhausted state in chronic HIV infection. Even in early phase of HIV infection, the dysfunction of HIV-specific T cells can be observed in rapid progressors, but the underlying mechanisms are not fully understood. Cytokines play a central role in regulating T cell function. In this study, we sought to elucidate whether IL-33/ST2 axis plays roles in the regulation of T cell function in HIV infection. We found that the level of IL-33 was upregulated in early HIV-infected patients compared with that in healthy controls and has a trend associated with disease progression. In vitro study shows that IL-33 promotes the expression of IFN-γ by Gag stimulated CD4+ and CD8+T cells from HIV-infected patients to a certain extent. However, soluble ST2 (sST2), a decoy receptor of IL-33, was also increased in early HIV infected patients, especially in those with progressive infection. We found that anti-ST2 antibodies attenuated the effect of IL-33 to CD4+ and CD8+T cells. Our data indicates that elevated expression of IL-33 in early HIV infection has the potential to enhance the function of T cells, but the upregulated sST2 weakens the activity of IL-33, which may indirectly contribute to the dysfunction of T cells and rapid disease progression. This data broadens the understanding of HIV pathogenesis and provides critical information for HIV intervention.

Biology-driven developments in the therapy of acute graft-versus-host disease

Allogeneic hematopoietic cell transplantation is a potentially curative treatment of different hematological malignancies. A major life-threatening complication is acute graft-versus-host disease (GVHD), in particular when the disease becomes steroid refractory. Based on the detection of pathogenic cytokines, chemokines, and T-cell subsets in individuals developing GVHD or experimental GVHD models, different therapeutic strategies have been developed. A potential cause why targeting individual receptors can lack efficacy could be that multiple cytokines, danger signals, and chemokine that have redundant functions are released during GVHD. To overcome this redundancy, novel strategies that do not target individual surface molecules like chemokine receptors, integrins, and cytokine receptors, but instead inhibit signaling pathways downstream of these molecules, have been tested in preclinical GVHD models and are currently being tested in clinical GVHD trials. Another important development is tissue regenerative approaches that promote healing of GVHD-related tissue damage as well as strategies that rely on microbiota modifications. These approaches are promising because they act very differently from conventional immunosuppression, instead aiming at reinstalling tissue homeostasis and microbiome diversity. This review discusses major novel developments in GVHD therapy that are based on a better understanding of GVHD biology, the repurposing of novel kinase inhibitors, microbiome modification strategies, and tissue-regenerative approaches.

GVHD: biology matters

Acute graft-versus-host disease (GVHD) targets the crypts in the gastrointestinal (GI) tract that are responsible for the self-renewal of the intestinal mucosa. Recent advances in the identification and culture of intestinal stem cells have improved our understanding of the interactions between the microbiome and the immune system (both innate and adaptive) that are key to the pathophysiology of GVHD. The identification of serum biomarkers that best predict long-term GVHD outcomes derive from the GI tract and have focused attention on cellular elements that act as shields against GVHD as well as its targets. These biomarkers have illuminated new mechanisms of crypt biology and provided insights that should prove useful both in the design of clinical trials and as guides to GVHD prevention and treatment.

Increased serum concentrations of soluble ST2 predict mortality after burn injury

Background:

Large burn injuries induce a systemic response in affected patients. Soluble ST2 (sST2) acts as a decoy receptor for interleukin-33 (IL-33) and has immunosuppressive effects. sST2 has been described previously as a prognostic serum marker. Our aim was to evaluate serum concentrations of sST2 and IL-33 after thermal injury and elucidate whether sST2 is associated with mortality in these patients.

Methods:

We included 32 burn patients (total body surface area [TBSA] >10%) admitted to our burn intensive care unit and compared them to eight healthy probands. Serum concentrations of sST2 and IL-33 were measured serially using an enzyme-linked immunosorbent assay (ELISA) technique.

Results:

The mean TBSA was 32.5%±19.6%. Six patients (18.8%) died during the hospital stay. Serum analyses showed significantly increased concentrations of sST2 and reduced concentrations of IL-33 in burn patients compared to healthy controls. In our study cohort, higher serum concentrations of sST2 were a strong independent predictor of mortality.

Conclusions:

Burn injuries cause an increment of sST2 serum concentrations with a concomitant reduction of IL-33. Higher concentrations of sST2 are associated with increased in-hospital mortality in burn patients.

NLRP3 Inflammasome and IL-33: Novel Players in Sterile Liver Inflammation

In sterile liver inflammation, danger signals are released in response to tissue injury to alert the immune system; e.g., by activation of the NLRP3 inflammasome. Recently, IL-33 has been identified as a novel type of danger signal or “alarmin”, which is released from damaged and necrotic cells. IL-33 is a pleiotropic cytokine that targets a broad range of immune cells and exhibits pro- and anti-inflammatory properties dependent on the disease. This review summarizes the immunomodulatory roles of the NLRP3 inflammasome and IL-33 in sterile liver inflammation and highlights potential therapeutic strategies targeting these pathways in liver disease.

Biomarkers for posttransplantation outcomes

During the last decade, the development of biomarkers for the complications seen after allogeneic hematopoietic stem cell transplantation has expanded tremendously, with the most progress having been made for acute graft-versus-host disease (aGVHD), a common and often fatal complication. Although many factors are known to determine transplant outcome (including the age of the recipient, comorbidity, conditioning intensity, donor source, donor-recipient HLA compatibility, conditioning regimen, posttransplant GVHD prophylaxis), they are incomplete guides for predicting outcomes. Thanks to the advances in genomics, transcriptomics, proteomics, and cytomics technologies, blood biomarkers have been identified and validated for us in promising diagnostic tests, prognostic tests stratifying for future occurrence of aGVHD, and predictive tests for responsiveness to GVHD therapy and nonrelapse mortality. These biomarkers may facilitate timely and selective therapeutic intervention. However, such blood tests are not yet available for routine clinical care. This article provides an overview of the candidate biomarkers for clinical evaluation and outlines a path from biomarker discovery to first clinical correlation, to validation in independent cohorts, to a biomarker-based clinical trial, and finally to general clinical application. This article focuses on biomarkers discovered with a large-scale proteomics platform and validated with the same reproducible assay in at least 2 independent cohorts with sufficient sample size according to the 2014 National Institutes of Health consensus on biomarker criteria, as well as on biomarkers as tests for risk stratification of outcomes, but not on their pathophysiologic contributions, which have been reviewed recently.

Dichotomous function of IL-33 in health and disease: From biology to clinical implications

Interleukin (IL)-33 is a cytokine that is released from epithelial and endothelial cells at barrier surfaces upon tissue stress or damage to operate as an alarmin. IL-33 has been primarily implicated in the induction of T helper (Th) 2 type immune responses. Therefore, IL-33 has attracted a lot of interest as a potential therapeutic target in asthma and other allergic diseases. Over the years, it has become clear that IL-33 has a much broader activity and also contributes to Th1 immunity, expanding the possibilities for therapeutic modulation of IL-33 activity to multiple inflammatory diseases. However, more recently IL-33 has also been shown to mediate immunosuppression and tissue repair by activating regulatory T cells (Treg) and promoting M2 macrophage polarization. These pleiotropic activities of IL-33 illustrate the need for a tight molecular regulation of IL-33 activity, and have to be taken into account when IL-33 or its receptor is targeted for therapeutic modulation. Here we review the multiple molecular mechanisms that regulate IL-33 activity and describe how IL-33 can shape innate and adaptive immune responses by promoting Th1, Th2 and Treg function. Finally, we will discuss the possibilities for therapeutic modulation of IL-33 signaling as well as possible safety issues.

IL-33 in Tumor Immunity: Nothing to Sneeze At

Although immunotherapy has been at the forefront of cancer therapy for the last several years, better clinical responses are still desired. Interleukin-33 is perhaps one of the most overlooked antitumor cytokines. Its ability to promote type 1 immune responses, which control tumor growth in preclinical animal models is overshadowed by its association with type 2 immunity and poor prognosis in some human cancers. Accumulating evidence shows that IL-33 is a powerful new tool for restoring and enhancing the body's natural antitumor immunity cycle. Furthermore, the antitumor mechanisms of IL-33 are two-fold, as it can directly boost CD8+ T cell function and restore dendritic cell dysfunction in vivo. Mechanistic studies have identified a novel pathway induced by IL-33 and its receptor ST2 in which dendritic cells avoid dysfunction and retain cross-priming abilities in tumor-bearing conditions. Here, we also comment on IL-33 data in human cancers and explore the idea that endogenous IL-33 may not deserve its reputation for promoting tumor growth. In fact, tumors may hijack the IL-33/ST2 axis to avoid immune surveillance and escape antitumor immunity.

Serum suppression of tumorigenicity 2 level is an independent predictor of all-cause mortality in HIV-infected patients

OBJECTIVE

To evaluate the predictive value of soluble suppression of tumorigenicity 2 (sST2), a decoy receptor of IL-33 involved in several inflammatory and immune diseases, for death in HIV infection.

DESIGN

Patients enrolled in the ANRS CO3 Aquitaine Cohort, a prospective hospital-based cohort of HIV-1-infected patients, who had a plasma sample available in the biobank were systematically eligible.

METHODS

sST2, soluble CD14 (sCD14) and IL-6 were measured using Luminex multiplex bead-based technology (R&D Systems) and a Bio-Plex 200 instrument (BioRad). Predictive capacities of sST2, sCD14, IL-6 and of the Veterans Aging Cohort Study clinical score at baseline on overall mortality were compared using multivariable Cox proportional hazards models.

RESULTS

During a median follow-up of 7.2 years [interquartile range (IQR): 6.0; 7.9], 93 deaths from all causes (incidence rate 9.9 per 1000 patient-years; 95% confidence interval 7.9-11.9) were reported in 1414 patients. The median sST2 baseline concentration was 22.9 ng/ml (IQR: 17.7; 30.3) and was higher (30.8 ng/ml, IQR: 21.5; 42.1) in patients who died as compared with those who stayed alive (22.6 ng/ml; IQR: 17.5; 29.6) (P < 10). An increased risk of death of 21% for a concentration 10.0 ng/ml higher of sST2 remained after adjustment for sCD14, IL-6 and Veterans Aging Cohort Study score (adjusted hazard ratio: 1.21; P < 10). The predictive capacity of sST2 was confirmed in a validation cohort (n = 386, 31 deaths) with an improved area c-index from 0.804 without sST2 to 0.811 with sST2.

CONCLUSION

sST2 is a new valuable biomarker to evaluate the risk of all-cause mortality in HIV disease.

New Insights into Graft-Versus-Host Disease and Graft Rejection

Allogeneic transplantation of foreign organs or tissues has lifesaving potential, but can lead to serious complications. After solid organ transplantation, immune-mediated rejection mandates the use of prolonged global immunosuppression and limits the life span of transplanted allografts. After bone marrow transplantation, donor-derived immune cells can trigger life-threatening graft-versus-host disease. T cells are central mediators of alloimmune complications and the target of most existing therapeutic interventions. We review recent progress in identifying multiple cell types in addition to T cells and new molecular pathways that regulate pathogenic alloreactivity. Key discoveries include the cellular subsets that function as potential sources of alloantigens, the cross talk of innate lymphoid cells with damaged epithelia and with the recipient microbiome, the impact of the alarmin interleukin-33 on alloreactivity, and the role of Notch ligands expressed by fibroblastic stromal cells in alloimmunity. While refining our understanding of transplantation immunobiology, these findings identify new therapeutic targets and new areas of investigation.

Harnessing Advances in T Regulatory Cell Biology for Cellular Therapy in Transplantation

Cellular therapy with CD4FOXP3 T regulatory (Treg) cells is a promising strategy to induce tolerance after solid-organ transplantation or prevent graft-versus-host disease after transfer of hematopoietic stem cells. Treg cells currently used in clinical trials are either polyclonal, donor- or antigen-specific. Aside from variations in isolation and expansion protocols, however, most therapeutic Treg cell-based products are much alike. Ongoing basic science work has provided considerable new insight into multiple facets of Treg cell biology, including their stability, homing, and functional specialization; integrating these basic science discoveries with clinical efforts will support the development of next-generation therapeutic Treg cells with enhanced efficacy. In this review, we summarize recent advances in knowledge of how Treg cells home to lymphoid and peripheral tissues, and control antibody production and tissue repair. We also discuss newly appreciated pathways that modulate context-specific Treg cell function and stability. Strategies to improve and tailor Treg cells for cell therapy to induce transplantation tolerance are highlighted.

Changes in protein serum levels during stem cell transplantation

BACKGROUND

GvHD is one of the major complication after stem cell transplantation affecting transplant-related mortality. Throughout the last years, many serum proteins were been proposed as possible biomarkers for GvHD.

AIMS

We studied the trend of five of the most studied serum proteins to evaluate whether a correlation exists between proteins concentration and post-HSCT outcomes.

MATERIALS AND METHODS

We measured serum concentration of REG3α, ST2, B-cell activating factor (BAFF), CXCL9 and elafin in a cohort of 77 patients submitted to Hematopoietic allogeneic stem cell transplantation (HSCT) in our department. Blood samples were been collected at baseline, day +30, GvHD onset and GvHD resolution.

RESULTS

REG3α levels showed an association only with acute GvHD. Elafin and ST2 levels varied according to both acute and chronic GvHD occurrence. BAFF concentration showed an inverse association with acute GvHD development. Interestingly, baseline BAFF and ST2 levels predicted post-HSCT survival. No associations were found for CXCL9.

CONCLUSIONS

Except for CXCL9, the protein levels seem to change according to GvHD development, independently from organ involvement and grading. Pretransplant ST2 and BAFF appeared to be predictors for survival after HSCT.

Vorinostat plus tacrolimus/methotrexate to prevent GVHD after myeloablative conditioning, unrelated donor HCT

The oral histone deacetylase (HDAC) inhibitor (vorinostat) is safe and results in low incidence of acute graft-versus-host disease (GVHD) after reduced-intensity conditioning, related donor hematopoietic cell transplantation (HCT). However, its safety and efficacy in preventing acute GVHD in settings of heightened clinical risk that use myeloablative conditioning, unrelated donor (URD), and methotrexate are not known. We conducted a prospective, phase 2 study in this higher-risk setting. We enrolled 37 patients to provide 80% power to detect a significant difference in grade 2 to 4 acute GVHD of 50% compared with a reduction in target to 28%. Eligibility included adults with a hematological malignancy to receive myeloablative HCT from an available 8/8-HLA matched URD. Patients received GVHD prophylaxis with tacrolimus and methotrexate. Vorinostat (100 mg twice daily) was started on day -10 and continued through day +100 post-HCT. Median age was 56 years (range, 18-69 years), and 95% had acute myelogenous leukemia or high-risk myelodysplastic syndrome. Vorinostat was safe and tolerable. The cumulative incidence of grade 2 to 4 acute GVHD at day 100 was 22%, and for grade 3 to 4 it was 8%. The cumulative incidence of chronic GVHD was 29%; relapse, nonrelapse mortality, GVHD-free relapse-free survival, and overall survival at 1 year were 19%, 16%, 47%, and 76%, respectively. Correlative analyses showed enhanced histone (H3) acetylation in peripheral blood mononuclear cells and reduced interleukin 6 (P = .028) and GVHD biomarkers (Reg3, P = .041; ST2, P = .002) at day 30 post-HCT in vorinostat-treated subjects compared with similarly treated patients who did not receive vorinostat. Vorinostat for GVHD prevention is an effective strategy that should be confirmed in a randomized phase 3 study. This trial was registered at www.clinicaltrials.gov as #NCT01790568.

Role of the intestinal mucosa in acute gastrointestinal GVHD

Intestinal graft-versus-host disease (GVHD) remains a significant obstacle to the success of allogeneic hematopoietic cell transplantation. The intestinal mucosa comprises the inner lining of the intestinal tract and maintains close proximity with commensal microbes that reside within the intestinal lumen. Recent advances have significantly improved our understanding of the interactions between the intestinal mucosa and the enteric microbiota. Changes in host mucosal tissue and commensals posttransplant have been actively investigated, and provocative insights into mucosal immunity and the enteric microbiota are now being translated into clinical trials of novel approaches for preventing and treating acute GVHD. In this review, we summarize recent findings related to aspects of the intestinal mucosa during acute GVHD.

IL-33 and the intestine: The good, the bad, and the inflammatory

Interleukin-33 (IL-33) is a member of the IL-1 cytokine family that has been widely studied since its discovery in 2005 for its dichotomous functions in homeostasis and inflammation. IL-33, along with its receptor suppression of tumorigenicity 2 (ST2), has been shown to modulate both the innate and adaptive immune system. Originally, the IL-33/ST2 signaling axis was studied in the context of inducing type 2 immune responses with the expression of ST2 by T helper 2 (T_H2) cells. However, the role of IL-33 is not limited to T_H2 responses. Rather, IL-33 is a potent activator of T_H1 cells, group 2 innate lymphoid cells (ILC2s), regulatory T (Treg) cells, and CD8⁺ T cells. The intestine is uniquely important in this discussion, as the intestinal epithelium is distinctively positioned to interact with both pathogens and the immune cells housed in the mucosa. In the intestine, IL-33 is expressed by the pericryptal fibroblasts and its expression is increased particularly in disease states. Moreover, IL-33/ST2 signaling aberrancy is implicated in the pathogenesis of inflammatory bowel disease (IBD). Accordingly, for this review, we will focus on the role of IL-33 in the regulation of intestinal immunity, involvement in intestinal disease, and implication in potential therapeutics.

Interleukin-33 signaling contributes to renal fibrosis following ischemia reperfusion

Acute kidney injury caused by ischemia-reperfusion injury (IRI) is a major risk factor for chronic kidney disease, which is characterized by renal interstitial fibrosis. However, the molecular mechanisms underlying renal fibrosis induced by IRI are not fully understood. Our results showed that interleukin (IL)-33 was induced markedly after IRI insult, and the kidneys of mice following IRI plus IL-33 treatment presented more severe renal fibrosis compared with mice treated with IRI alone. Therefore, we investigated whether inhibition of IL-33 protects against IRI-induced renal fibrosis. Mice were administrated with soluble ST2 (sST2), a decoy receptor that neutralizes IL-33 activity, or vehicle by intraperitoneal injection for 14 days after IRI challenge. We revealed that mice treated with sST2 exhibited less severe renal dysfunction and fibrosis in response to IRI compared with vehicle-treated mice. Inhibition of IL-33 suppressed bone marrow-derived fibroblast accumulation and myofibroblast formation in the kidneys after IRI stress, which was associated with less expression of extracellular matrix proteins. Furthermore, inhibition of IL-33 also showed a significant reduction of F4/80⁺ macrophages and CD3⁺ T cells in the kidneys of mice after IRI treatment. Finally, Treatment with IL-33 inhibitor reduced proinflammatory cytokine and chemokine levels in the kidneys of mice following IRI insult. Taken together, our findings indicate that IL-33 signaling plays a critical role in the pathogenesis of IRI-induced renal fibrosis through regulating myeloid fibroblast accumulation, inflammation cell infiltration, and the expression of proinflammatory cytokines and chemokines.

Transplant-associated thrombotic microangiopathy is an endothelial complication associated with refractoriness of acute GvHD

There is increasing evidence that endothelial dysfunction is involved in refractoriness of acute GvHD (aGvHD). Here we investigated the hypothesis that another endothelial complication, transplant-associated thrombotic microangiopathy (TMA), contributes to the pathogenesis of aGvHD refractoriness. TMA was retrospectively assessed in 771 patients after allogeneic stem cell transplantation (alloSCT). Incidences of TMA and refractory aGvHD were correlated with biomarkers of endothelial damage obtained before alloSCT for patients receiving or not receiving statin-based endothelial prophylaxis (SEP). Diagnostic criteria for TMA and refractory aGvHD were met by 41 (5.3%) and 76 (10%) patients, respectively. TMA was overrepresented in patients with refractory aGvHD (45.0 vs 2.3% in all other patients, P<0.001). TMA independently increased mortality. Elevated pretransplant suppressor of tumorigenicity-2 and nitrates along with high-risk variants of the thrombomodulin gene were associated with increased risk of TMA. In contrast, SEP abolished the unfavorable outcome predicted by pretransplant biomarkers on TMA risk. Patients on SEP had a significantly lower risk of TMA (P=0.001) and refractory aGvHD (P=0.055) in a multivariate multistate model. Our data provide evidence that TMA contributes to the pathogenesis of aGvHD refractoriness. Patients with an increased TMA risk can be identified pretransplant and may benefit from pharmacological endothelium protection.

Altered homeostatic regulation of innate and adaptive immunity in lower gastrointestinal tract GVHD pathogenesis

Lower gastrointestinal (GI) tract graft-versus-host disease (GVHD) is the predominant cause of morbidity and mortality from GVHD after allogeneic stem cell transplantation. Recent data indicate that lower GI tract GVHD is a complicated process mediated by donor/host antigenic disparities. This process is exacerbated by significant changes to the microbiome, and innate and adaptive immune responses that are critical to the induction of disease, persistence of inflammation, and a lack of response to therapy. Here, we discuss new insights into the biology of lower GI tract GVHD and focus on intrinsic pathways and regulatory mechanisms crucial to normal intestinal function. We then describe multiple instances in which these homeostatic mechanisms are altered by donor T cells or conditioning therapy, resulting in exacerbation of GVHD. We also discuss data suggesting that some of these mechanisms produce biomarkers that could be informative as to the severity of GVHD and its response to therapy. Finally, novel therapies that might restore homeostasis in the GI tract during GVHD are highlighted.

Replicating viral vector platform exploits alarmin signals for potent CD8+ T cell-mediated tumour immunotherapy

Viral infections lead to alarmin release and elicit potent cytotoxic effector T lymphocyte (CTL^eff) responses. Conversely, the induction of protective tumour-specific CTL^eff and their recruitment into the tumour remain challenging tasks. Here we show that lymphocytic choriomeningitis virus (LCMV) can be engineered to serve as a replication competent, stably-attenuated immunotherapy vector (artLCMV). artLCMV delivers tumour-associated antigens to dendritic cells for efficient CTL priming. Unlike replication-deficient vectors, artLCMV targets also lymphoid tissue stroma cells expressing the alarmin interleukin-33. By triggering interleukin-33 signals, artLCMV elicits CTL^eff responses of higher magnitude and functionality than those induced by replication-deficient vectors. Superior anti-tumour efficacy of artLCMV immunotherapy depends on interleukin-33 signalling, and a massive CTL^eff influx triggers an inflammatory conversion of the tumour microenvironment. Our observations suggest that replicating viral delivery systems can release alarmins for improved anti-tumour efficacy. These mechanistic insights may outweigh safety concerns around replicating viral vectors in cancer immunotherapy.

Viruses trigger potent cytotoxic T cell responses, whereas anti-tumour immunity has been difficult to establish. Here the authors engineer a replicating viral delivery system for tumour-associated antigens, which induces alarmin release, innate activation and protective anti-tumour immunity in mice.

Predictive Value of Clinical Findings and Plasma Biomarkers after Fourteen Days of Prednisone Treatment for Acute Graft-versus-host Disease

We examined the hypothesis that plasma biomarkers and concomitant clinical findings after initial glucocorticoid therapy can accurately predict failure of graft-versus-host-disease (GVHD) treatment and mortality. We analyzed plasma samples and clinical data in 165 patients after 14 days of glucocorticoid therapy and used logistic regression and areas under receiver-operating characteristic curves (AUC) to evaluate associations with treatment failure and nonrelapse mortality (NRM). Initial treatment of GVHD was unsuccessful in 49 patients (30%). For predicting GVHD treatment failure, the best clinical combination (total serum bilirubin and skin GVHD stage: AUC, .70) was competitive with the best biomarker combination (T cell immunoglobulin and mucin domain 3 [TIM3] and [interleukin 1 receptor family encoded by the IL1RL1 gene, ST2]: AUC, .73). The combination of clinical features and biomarker results offered only a slight improvement (AUC, .75). For predicting NRM at 1 year, the best clinical predictor (total serum bilirubin: AUC, .81) was competitive with the best biomarker combination (TIM3 and soluble tumor necrosis factor receptor-1 [sTNFR1]: AUC, .85). The combination offered no improvement (AUC, .85). Infection was the proximate cause of death in virtually all patients. We conclude that after 14 days of glucocorticoid therapy, clinical findings (serum bilirubin, skin GVHD) and plasma biomarkers (TIM3, ST2, sTNFR1) can predict failure of GVHD treatment and NRM. These biomarkers reflect counter-regulatory mechanisms and provide insight into the pathophysiology of GVHD reactions after glucocorticoid treatment. The best predictive models, however, exhibit inadequate positive predictive values for identifying high-risk GVHD cohorts for investigational trials, as only a minority of patients with high-risk GVHD would be identified and most patients would be falsely predicted to have adverse outcomes.

The ST2/IL-33 Axis in Immune Cells during Inflammatory Diseases

Il1rl1 (also known as ST2) is a member of the IL-1 superfamily, and its only known ligand is IL-33. ST2 exists in two forms as splice variants: a soluble form (sST2), which acts as a decoy receptor, sequesters free IL-33, and does not signal, and a membrane-bound form (ST2), which activates the MyD88/NF-κB signaling pathway to enhance mast cell, Th2, regulatory T cell (Treg), and innate lymphoid cell type 2 functions. sST2 levels are increased in patients with active inflammatory bowel disease, acute cardiac and small bowel transplant allograft rejection, colon and gastric cancers, gut mucosal damage during viral infection, pulmonary disease, heart disease, and graft-versus-host disease. Recently, sST2 has been shown to be secreted by intestinal pro-inflammatory T cells during gut inflammation; on the contrary, protective ST2-expressing Tregs are decreased, implicating that ST2/IL-33 signaling may play an important role in intestinal disease. This review will focus on what is known on its signaling during various inflammatory disease states and highlight potential avenues to intervene in ST2/IL-33 signaling as treatment options.

Emerging Roles of IL-33/ST2 Axis in Renal Diseases

Renal diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD), have a great impact on health care systems worldwide. Similar to cardiovascular diseases, renal diseases are inflammatory diseases involving a variety of cytokines. Primary causes of renal injury include ischemia, uremic toxins, bacteremia, or nephrotoxicity. Inflammation represents an important component following kidney injury. Interleukin (IL)-33 is a member of the IL-1 cytokine family, which is widely expressed in epithelial barrier tissues and endothelial cells, and mediates both tissue inflammation and repair responses. IL-33 is released as a nuclear alarmin in response to tissue damage and triggers innate and adaptive immune responses by binding to its receptor, suppression of tumorigenicity 2 (ST2). Recent evidence from clinical and experimental animal studies indicates that the IL-33/ST2 axis is involved in the pathogenesis of CKD, renal graft injury, systemic lupus nephritis, and AKI. In this review, we discuss the pathological and tissue reparative roles of the IL-33/ST2 pathway in different types of renal diseases.

Type 2 innate lymphoid cells treat and prevent acute gastrointestinal graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is the most common complication for patients undergoing allogeneic stem cell transplantation. Despite extremely aggressive therapy targeting donor T cells, patients with grade III or greater aGVHD of the lower GI tract, who do not respond to therapy with corticosteroids, have a dismal prognosis. Thus, efforts to improve understanding of the function of local immune and non-immune cells in regulating the inflammatory process in the GI tract during aGVHD are needed. Here, we demonstrate, using murine models of allogeneic BMT, that type 2 innate lymphoid cells (ILC2s) in the lower GI tract are sensitive to conditioning therapy and show very limited ability to repopulate from donor bone marrow. Infusion of donor ILC2s was effective in reducing the lethality of aGVHD and in treating lower GI tract disease. ILC2 infusion was associated with reduced donor proinflammatory Th1 and Th17 cells, accumulation of donor myeloid-derived suppressor cells (MDSCs) mediated by ILC2 production of IL-13, improved GI tract barrier function, and a preserved graft-versus-leukemia (GVL) response. Collectively, these findings suggest that infusion of donor ILC2s to restore gastrointestinal tract homeostasis may improve treatment of severe lower GI tract aGVHD.

Clinical impact of hyperglycemia on days 0-7 after allogeneic stem cell transplantation

In order to clarify the association between hyperglycemia during the early period after allogeneic stem cell transplantation (allo-SCT) and adverse outcomes, we retrospectively analyzed 563 consecutive patients who underwent allo-SCT at our institute between 2008 and 2015. Patients were categorized into three groups according to mean fasting blood glucose levels on days 0-7 (normoglycemia group<110 mg/dL, n=347; mild hyperglycemia group 110-149 mg/dL, n=192 and moderate/severe hyperglycemia group≥150 mg/dL, n=24). The median follow-up was 2.7 years. Patients in the moderate/severe hyperglycemia group had significantly worse characteristics. The cumulative incidences of 2-year non-relapse mortality (NRM) and the probabilities of 2-year overall survival (OS) in the normoglycemia, mild hyperglycemia and moderate/severe hyperglycemia groups were 7.5%, 19% and 29%, respectively (P<0.01), and 69%, 53% and 33%, respectively (P<0.01). In multivariate analyses, hyperglycemia was an independent predictor of high NRM (vs normoglycemia; mild hyperglycemia, hazard ratio (HR) 2.56, 95% confidence interval (CI) 1.56-4.18; moderate/severe hyperglycemia, HR 4.46, 95% CI 1.92-10.3) and poor OS (vs normoglycemia; mild hyperglycemia, HR 1.54, 95% CI 1.14-2.07; moderate/severe hyperglycemia, HR 1.61, 95% CI 0.89-2.91). In conclusion, hyperglycemia on days 0-7 after allo-SCT was associated with inferior outcomes.

Effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver: study in the experimental model of Zucker rats

Suppression of tumorigenicity 2 (ST2) mediates the effect of Interleukin-33 (IL-33). Few data are reported on the relationship between IL-33/ST2 and obesity. We aimed to investigate effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver in a rodent model of obesity. The relationship of cardiac expression of IL-33/ST2 system with natriuretic peptides (NPs) system and inflammatory mediators was also studied. mRNA expression of IL-33/ST2 system was evaluated in cardiac, adipose and hepatic biopsies from obese Zucker rats (O) and controls (CO). Expression levels of sST2 was significantly lower in O rats compared with CO (p<0.05) in all tissues. Besides, the mRNA levels of IL-33 decreased significant in fat of O respect to CO, while, expression levels of ST2L was significantly higher in liver of CO than in O. A strong relationship of IL-33/ST2 with NPs and classical inflammatory mediators was observed in cardiac tissue. Expression of sST2 in cardiac, adipose and liver tissue decreased in O compared with controls, suggesting an involvement for IL-33/ST2 system in molecular mechanisms of obesity. The strong relationships with NP systems and inflammatory mediators could suggest an involvement for IL-33/ST2 in molecular pathways leading to cardiac dysfunction and inflammation associated with obesity.