IL-33 and ST2 levels in chronic kidney disease: Associations with inflammation, vascular abnormalities, cardiovascular events, and survival

Amniotic fluid proteomic analysis identifies IL1RL1, APOE, and NECTIN4 as new biomarkers for preterm birth

BACKGROUND

Despite extensive research, the identification of effective biomarkers for early prediction of preterm birth (PTB) continues to be a challenging endeavor. This study aims to identify amniotic fluid (AF) protein biomarkers useful for the early diagnosis of PTB.

METHODS

We initially identified the protein expression profiles in the AF of women with PTB (n = 22) and full-term birth (FTB, n = 22), from the First People's Hospital of Yunnan Province who underwent amniocentesis from November 2019 to February 2020, using mass spectrometry employing the data-independent acquisition (DIA) technique, and then analyzed differentially expressed proteins (DEPs). Subsequently, the least absolute shrinkage and selection operator (LASSO) and random forest analysis were employed to further screen the key proteins for PTB biomarker identification. The receiver operating characteristic (ROC) analysis, calibration plots, and decision curve analyses (DCA) were utilized to assess the discrimination and calibration of the key biomarkers.

RESULTS

A total of 25 DEPs were identified between the PTB and FTB groups, comprising 13 up-regulated and 12 down-regulated proteins. Three key protein biomarkers for early PTB diagnosis were identified: IL1RL1 (interleukin-1 receptor-like 1), APOE (apolipoprotein E), and NECTIN4 (nectin cell adhesion molecule 4). The results of the ROC analysis showed that the area under the curve (AUC) of the three proteins combined as a biomarker for early diagnosis of PTB was 0.913 (95% CI: 0.823-1.000), with a sensitivity of 0.864 and a specificity of 0.955, both superior to those of the individual biomarkers. Bootstrap internal validation revealed a concordance index (C-index) of 0.878, with a sensitivity of 0.812 and a specificity of 0.773, indicating the robust predictive performance of these biomarkers.

CONCLUSIONS

We identified three previously unexplored yet potentially useful protein biomarkers in AF for early PTB diagnosis: IL1RL1, APOE, and NECTIN4.

Inhibition of Interleukin-33 to Reduce Glomerular Endothelial Inflammation in Diabetic Kidney Disease

Introduction

Inflammation is a significant contributor to cardiorenal morbidity and mortality in diabetic kidney disease (DKD). The pathophysiological mechanisms linking systemic, subacute inflammation and local, kidney injury-initiated immune maladaptation is partially understood.

Methods

Here, we explored the expression of proinflammatory cytokines in patients with DKD; investigated mouse models of type 1 and type 2 diabetes (T2D); evaluated glomerular signaling in vitro; performed post hoc analyses of systemic and urinary markers of inflammation; and initiated a phase 2b clinical study (FRONTIER-1; NCT04170543).

Results

Transcriptomic profiling of kidney biopsies from patients with DKD revealed significant glomerular upregulation of interleukin-33 (IL-33). Inhibition of IL-33 signaling reduced glomerular damage and albuminuria in the uninephrectomized db/db mouse model (T2D/DKD). On a cellular level, inhibiting IL-33 improved glomerular endothelial health by decreasing cellular inflammation and reducing release of proinflammatory cytokines. Therefore, FRONTIER-1 was designed to test the safety and efficacy of the IL-33-targeted monoclonal antibody tozorakimab in patients with DKD. So far, 578 patients are enrolled in FRONTIER-1. The baseline inflammation status of participants (N > 146) was assessed in blood and urine. Comparison to independent reference cohorts (N > 200) validated the distribution of urinary tumor necrosis factor receptor 1 (TNFR1) and C-C motif chemokine ligand 2 (CCL2). Treatment with dapagliflozin for 6 weeks did not alter these biomarkers significantly.

Conclusion

We show that blocking the IL-33 pathway may mitigate glomerular endothelial inflammation in DKD. The findings from the FRONTIER-1 study will provide valuable insights into the therapeutic potential of IL-33 inhibition in DKD.

Advancements in diabetic kidney disease management: integrating innovative therapies and targeted drug development

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease and affects approximately 40% of individuals with diabetes . Cases of DKD continue to rise globally as the prevalence of diabetes mellitus increases, with an estimated 415 million people living with diabetes in 2015 and a projected 642 million by 2040. DKD is associated with significant morbidity and mortality, representing 34% and 36% of all chronic kidney disease deaths in men and women, respectively. Common comorbidities including hypertension and ageing-related nephron loss further complicate disease diagnosis and progression. The progression of DKD involves several mechanisms including glomerular endothelial cell dysfunction, inflammation, and fibrosis. Targeting these mechanisms has formed the basis of several therapeutic agents. Renin-angiotensin-aldosterone system (RAAS) blockers, specifically angiotensin receptor blockers (ARBs), demonstrate significant reductions in macroalbuminuria. Sodium-glucose transporter type 2 (SGLT-2) inhibitors demonstrate kidney protection independent of diabetes control while also decreasing the incidence of cardiovascular events. Emerging agents including glucagon-like peptide 1 (GLP-1) agonists, anti-inflammatory agents like bardoxolone, and mineralocorticoid receptor antagonists show promise in mitigating DKD progression. Many novel therapies including monoclonal antibodies CSL346, lixudebart, and tozorakimab; mesenchymal stem/stromal cell infusion; and cannabinoid-1 receptor inverse agonism via INV-202 are currently in clinical trials and present opportunities for further drug development.

Association of soluble suppression of tumorigenicity 2 with mortality and adverse outcomes in chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Early risk stratification is necessary to prevent chronic kidney disease progression and complications. This systematic review aims to evaluate the association of soluble suppression of tumorigenicity 2 (sST2), a member of the interleukin-1 receptor family, with all-cause mortality, cardiovascular disease and renal function deterioration among chronic kidney disease patients.

METHODS

PubMed, Scopus, Web of Science, CENTRAL and Google Scholar were systematically searched from inception to December 20, 2023. Cohort studies examining the prognostic role of sST2 levels in pre-dialysis and dialysis patients were included. In case of 3 or more studies per outcome, conventional and dose-response meta-analyses were conducted.

RESULTS

Overall, 21 studies were included comprising 15,100 patients. In pre-dialysis patients, the qualitative synthesis of studies suggested that high sST2 is associated with significantly increased all-cause mortality, while evidence regarding cardiovascular events or kidney disease progression was conflicting. In the dialysis population, high sST2 was linked to an elevated risk of all-cause (Hazard ratio-HR: 3.00, 95% confidence intervals-CI: 1.95-4.61) and cardiovascular (HR: 2.38, 95% CI: 1.69-3.34) mortality. Dose-response meta-analysis suggested a log-linear association of sST2 with both all-cause (χ2: 34.65, p value < 0.001) and cardiovascular (χ2: 29.14, p value < 0.001) mortality, whereas findings regarding cardiovascular events were limited with mixed results.

CONCLUSIONS

High sST2 values are associated with an increased risk of all-cause mortality in pre-dialysis and dialysis patients, as well as with an elevated risk of cardiovascular mortality in the dialysis population. Further studies are needed to elucidate its potential association with cardiovascular events and kidney disease progression.

Osteoprotegerin and Inflammation in Incident Peritoneal Dialysis Patients

Objectives: Osteoprotegerin (OPG) is a member of the tumor necrosis factor receptor family involved in processes in many inflammatory states. OPG concentration is enhanced in the majority of chronic kidney disease (CKD) patients and those undergoing renal replacement therapy. The aim of the study was to assess the relation of OPG and chronic inflammation in peritoneal dialysis (PD) patients and to evaluate whether OPG concentrations in plasma and dialysate were related to plasma and dialysate levels of proinflammatory mediators (interleukin 6 (IL-6), high-sensitivity C-reactive protein (hsCRP), interleukin 33 (IL-33) and interleukin 1 receptor-like 1IL-1RL1 (IL-1RL1, sST2)). Methods: The study included 37 patients of the Peritoneal Dialysis Center, Department of Nephrology, Transplantology and Internal Medicine, Szczecin, Poland, 4-6 weeks after the onset of peritoneal dialysis therapy. During a peritoneal equilibration test, plasma (at 2 h) and dialysate (at 4 h) OPG, IL-33, 1IL-1RL1 (sST2), IL-6 and hsCRP concentrations were determined. Results: Plasma concentration of OPG did not correlate with dialysate OPG level (Rs = 0.04, p = 0.8). There was a strong positive correlation between plasma OPG concentrations and plasma IL-1RL1 (sST2) (Rs = 0.41; p = 0.01), plasma IL-6 (Rs = 0.38; p = 0.01) and plasma hsCRP (Rs = 0.35; p = 0.02). Dialysate OPG concentrations were positively associated with dialysate IL-1RL1 (sST2) (Rs = 0.37; p = 0.02) and dialysate IL-6 levels (Rs = 0.44; p = 0.005). Multivariate analysis showed that higher IL-1RL1 (sST2) (ß = +0.38, p = 0.006), higher plasma hsCRP (ß = +0.32, p = 0.02) and older age (ß = +0.35, p = 0.01) were independent determinants of higher plasma OPG concentration and that higher concentrations of dialysate IL-6 (ß = +0.37, p = 0.02) were independent determinants of higher dialysate OPG concentration. Conclusions: Both plasma and dialysate OPG levels are associated with the severity of systemic and local inflammation illustrated by the plasma and dialysate concentrations of IL-1RL1 (sST2), hsCRP and IL-6, suggesting that OPG might have a pivotal role in explaining the milieu of systemic and intraperitoneal inflammation.

Pediatric chronic kidney disease: blood cell count indexes as inflammation markers

INTRODUCTION

Chronic kidney disease (CKD) is defined as a progressive decline of kidney functions. In childhood, the main triggering factors are congenital anomalies of the kidneys and urinary tract (CAKUT) and glomerulopathies. Inflammatory responses present challenges for diagnosis and staging, which justifies studies on biomarkers/indexes.

AIM

To define blood cell count indexes and verify their association with pediatric CKD etiology and staging. The included indexes were: Neutrophil-Lymphocyte Ratio (NLR), Derived Neutrophil-Lymphocyte Ratio (dNLR), Lymphocyte-Monocyte Ratio (LMR), Systemic Inflammation Response Index (SIRI), Aggregate Index of Systemic Inflammation (AISI), and Systemic Immune-Inflammation Index (SII).

METHODS

We determined the indexes in 52 pediatric CKD patients and 33 healthy controls by mathematical calculation. CKD patients were separated in five groups based on the etiology and staging: Group IA: glomerulopathies at stage 1 or 2; IB: glomerulopathies at stage 3 or 4; IIA: CAKUT at stage 1 or 2; IIB: CAKUT at stage 3 or 4; and III: stages 3 or 4 of other etiologies. In addition, we combined all patients with CKD in one group (IV). Group V was a healthy control group.

RESULTS

Lower values of LMR were observed for groups IB and IIB compared to group V (p = 0.047, p = 0.031, respectively). Increased values of SIRI were found for group III versus group V (p = 0.030). There was no difference for other indexes when the groups were compared two by two.

CONCLUSION

The LMR and SIRI indexes showed promising results in the evaluation of inflammation, as they correlated with CKD etiologies and specially staging in these patients.

Interleukin-33/sST2: Dynamic assessment in patients with acute coronary syndrome

PURPOSE

Interleukin (IL)-33 and its soluble receptor ST2 (sST2) play a crucial role in the immune response. sST2 has been approved by the Food and Drug Administration as a prognostic biomarker of mortality in chronic heart failure patients, however, the role of IL-33 and sST2 in atherosclerotic cardiovascular disease remains unclear. The aim of this study was to measure serum level of IL-33 and sST2 of patients at the onset of acute coronary syndrome (ACS) and 3 months after primary percutaneous revascularization.

PATIENTS AND METHODS

Forty patients were divided into ST segment elevation myocardial infarction (STEMI) group, non-ST segment elevation myocardial infarction (NSTEMI) and unstable angina (UA) group. IL-33 and sST2 level were measured with ELISA. Additionally, IL-33 expression in peripheral blood mononuclear cells (PBMCs), was evaluated.

RESULTS

All ACS patients had a significantly lower level of sST2 3 months after ACS as compared to the baseline (p ​< ​0.039). The STEMI patients had higher serum levels of IL-33 at the moment of ACS as compared to 3 months after the event, with an average decrease of 17.87 ​pg/ml (p ​< ​0.007). Conversely, sST2 serum levels were still high after 3 months following an ACS in STEMI patients. ROC curve demonstrated that increased IL-33 serum level could be STEMI predictor.

CONCLUSIONS

The assessment of the baseline and dynamics of changes in IL-33 and sST2 concentrations in patients with ACS may be important for the diagnostic process and may help in understanding of how the immune mechanisms work at the moment of an ACS event.

Tozorakimab (MEDI3506): an anti-IL-33 antibody that inhibits IL-33 signalling via ST2 and RAGE/EGFR to reduce inflammation and epithelial dysfunction

Interleukin (IL)-33 is a broad-acting alarmin cytokine that can drive inflammatory responses following tissue damage or infection and is a promising target for treatment of inflammatory disease. Here, we describe the identification of tozorakimab (MEDI3506), a potent, human anti-IL-33 monoclonal antibody, which can inhibit reduced IL-33 (IL-33red) and oxidized IL-33 (IL-33ox) activities through distinct serum-stimulated 2 (ST2) and receptor for advanced glycation end products/epidermal growth factor receptor (RAGE/EGFR complex) signalling pathways. We hypothesized that a therapeutic antibody would require an affinity higher than that of ST2 for IL-33, with an association rate greater than 107 M-1 s-1, to effectively neutralize IL-33 following rapid release from damaged tissue. An innovative antibody generation campaign identified tozorakimab, an antibody with a femtomolar affinity for IL-33red and a fast association rate (8.5 × 107 M-1 s-1), which was comparable to soluble ST2. Tozorakimab potently inhibited ST2-dependent inflammatory responses driven by IL-33 in primary human cells and in a murine model of lung epithelial injury. Additionally, tozorakimab prevented the oxidation of IL-33 and its activity via the RAGE/EGFR signalling pathway, thus increasing in vitro epithelial cell migration and repair. Tozorakimab is a novel therapeutic agent with a dual mechanism of action that blocks IL-33red and IL-33ox signalling, offering potential to reduce inflammation and epithelial dysfunction in human disease.

Inflammatory mediators act at renal pericytes to elicit contraction of vasa recta and reduce pericyte density along the kidney medullary vascular network

Introduction: Regardless of initiating cause, renal injury promotes a potent pro-inflammatory environment in the outer medulla and a concomitant sustained decrease in medullary blood flow (MBF). This decline in MBF is believed to be one of the critical events in the pathogenesis of acute kidney injury (AKI), yet the precise cellular mechanism underlying this are still to be fully elucidated. MBF is regulated by contractile pericyte cells that reside on the descending vasa recta (DVR) capillaries, which are the primary source of blood flow to the medulla. Methods: Using the rat and murine live kidney slice models, we investigated the acute effects of key medullary inflammatory mediators TNF-α, IL-1β, IL-33, IL-18, C3a and C5a on vasa recta pericytes, the effect of AT1-R blocker Losartan on pro-inflammatory mediator activity at vasa recta pericytes, and the effect of 4-hour sustained exposure on immunolabelled NG2+ pericytes. Results and discussion: Exposure of rat and mouse kidney slices to TNF-α, IL-18, IL-33, and C5a demonstrated a real-time pericyte-mediated constriction of DVR. When pro-inflammatory mediators were applied in the presence of Losartan the inflammatory mediator-mediated constriction that had previously been observed was significantly attenuated. When live kidney slices were exposed to inflammatory mediators for 4-h, we noted a significant reduction in the number of NG2+ positive pericytes along vasa recta capillaries in both rat and murine kidney slices. Data collected in this study demonstrate that inflammatory mediators can dysregulate pericytes to constrict DVR diameter and reduce the density of pericytes along vasa recta vessels, further diminishing the regulatory capacity of the capillary network. We postulate that preliminary findings here suggest pericytes play a role in AKI.

Interleukin-33 Mediates Cardiomyopathy After Acute Kidney Injury by Signaling to Cardiomyocytes

BACKGROUND

Acute kidney injury (AKI) is a short-term life-threatening condition that, if survived, can lead to renal insufficiency and development of chronic kidney disease. The pathogenesis of AKI and chronic kidney disease involves direct effects on the heart and the development of hypertrophy and cardiomyopathy.

METHODS

We used mouse models of ischemia/reperfusion AKI and unilateral ureteral obstruction to investigate the role of IL-33 (interleukin-33) and its receptor-encoding gene Il1rl1 (also called ST2L [suppression of tumorigenicity 2]) in cardiac remodeling after AKI. Mice with cell type-specific genetic disruption of the IL-33/ST2L axis were used, and IL-33 monoclonal antibody, adeno-associated virus encoding IL-33 or ST2L, and recombinant IL-33, as well.

RESULTS

Mice deficient in Il33 were refractory to cardiomyopathy associated with 2 models of kidney injury. Treatment of mice with monoclonal IL-33 antibody also protected the heart after AKI. Moreover, overexpression of IL-33 or injection of recombinant IL-33 induced cardiac hypertrophy or cardiomyopathy, but not in mice lacking Il1rl1. AKI-induced cardiomyopathy was also reduced in mice with cardiac myocyte-specific deletion of Il1rl1 but not in endothelial cell- or fibroblast-specific deletion of Il1rl1. Last, overexpression of the ST2L receptor in cardiac myocytes recapitulated induction of cardiac hypertrophy.

CONCLUSIONS

These results indicate that IL-33 released from the kidney during AKI underlies cardiorenal syndrome by directly signaling to cardiac myocytes, suggesting that antagonism of IL-33/ST2 axis would be cardioprotective in patients with kidney disease.

Involvement of Atopic Dermatitis in the Development of Systemic Inflammatory Diseases

The skin is recognized as a peripheral lymphoid organ that plays an essential defensive action against external environmental stimuli. However, continuous stimulation of these factors causes chronic inflammation at the local site and occasionally causes tissue damage. Chronic inflammation is recognized as a trigger for systemic organ inflammation. Atopic dermatitis (AD) is a chronic inflammatory skin disease that is influenced by various external environmental factors, such as dry conditions, chemical exposure, and microorganisms. The pathogenesis of AD involves various Th2 and proinflammatory cytokines. Recently updated studies have shown that atopic skin-derived cytokines influence systemic organ function and oncogenesis. In this review, we focus on AD’s influence on the development of systemic inflammatory diseases and malignancies.

GDF-15 and sST-2 act as biomarkers of disease severity but not independent predictors in idiopathic membranous nephropathy

BACKGROUND

We aimed to explore biomarkers of disease severity in idiopathic membranous nephropathy (IMN) and independent predictors of prognosis in IMN.

METHODS

Clinical data were collected from 79 IMN patients. Serum levels of growth differentiation factor-15 (GDF-15) and soluble suppression of tumorigenicity (sST-2) were tested by enzyme-linked immunosorbent assay (ELISA) in IMN patients and subgroups, and correlation analysis was performed. Univariate and multiple logistic regression analyses were performed to identify independent predictors of IMN, and a combined-factors model was constructed. Moreover, the area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the prognostic efficacy.

RESULTS

The levels of GDF-15 were significantly higher in the IMN group and subgroups with low estimated glomerular filtration rate (eGFR) and high 24 hour-urine protein (24 h-UP), whiles sST-2 level was only significantly higher in the IMN group. GDF-15 levels were positively correlated with creatinine (Crea), cystatin C (Cys-C) and 24 h-UP and negatively correlated with GFR and albumin (Alb), while sST-2 levels were positively correlated with Urea and Cys-C and negatively correlated with eGFR. After one year of follow-up, 54 patients had incomplete remission. Serum phospholipase A2 receptor antibody (PLA2R-Ab), Urea, high-density lipoprotein cholesterol (HDL-C) and 24 h-UP but not GDF-15 and sST2 were independent predictors of prognosis in IMN patients, but combined factors showed the best prognostic efficacy.

CONCLUSION

Serum levels of GDF-15 and sST-2 may be potential biomarkers for the severity of IMN, while the combined-factors model is effective for predicting the risk factors of incomplete remission in IMN.

Interleukin-33 Exacerbates IgA Glomerulonephritis in Transgenic Mice Overexpressing B Cell Activating Factor

BACKGROUND

The cytokine IL-33 is an activator of innate lymphoid cells 2 (ILC2s) in innate immunity and allergic inflammation. B cell activating factor (BAFF) plays a central role in B cell proliferation and differentiation, and high levels of this protein cause excess antibody production, including IgA. BAFF-transgenic mice overexpress BAFF and spontaneously develop glomerulonephritis that resembles human IgA nephropathy.

METHODS

We administered IL-33 or PBS to wild-type and BAFF-transgenic mice. After treating Rag1-deficient mice with IL-33, with or without anti-CD90.2 to preferentially deplete ILC2s, we isolated splenocytes, which were adoptively transferred into BAFF-transgenic mice.

RESULTS

BAFF-transgenic mice treated with IL-33 developed more severe kidney dysfunction and proteinuria, glomerular sclerosis, tubulointerstitial damage, and glomerular deposition of IgA and C3. Compared with wild-type mice, BAFF-transgenic mice exhibited increases of CD19⁺ B cells in spleen and kidney and ILC2s in kidney and intestine, which were further increased by administration of IL-33. Administering IL-33 to wild-type mice had no effect on kidney function or histology, nor did it alter the number of ILC2s in spleen, kidney, or intestine. To understand the role of ILC2s, splenocytes were transferred from IL-33-treated Rag1-deficient mice into BAFF-transgenic mice. Glomerulonephritis and IgA deposition were exacerbated by transfer of IL-33-stimulated Rag1-deficient splenocytes, but not by ILC2 (anti-CD90.2)-depleted splenocytes. Wild-type mice infused with IL-33-treated Rag1-deficient splenocytes showed no change in kidney function or ILC2 numbers or distribution.

CONCLUSIONS

IL-33-expanded ILC2s exacerbated IgA glomerulonephritis in a mouse model. These findings indicate that IL-33 and ILC2s warrant evaluation as possible mediators of human IgA nephropathy.

Tissue-Dependent Adaptations and Functions of Innate Lymphoid Cells

Tissue-resident immune cells reside in distinct niches across organs, where they contribute to tissue homeostasis and rapidly respond to perturbations in the local microenvironment. Innate lymphoid cells (ILCs) are a family of innate immune cells that regulate immune and tissue homeostasis. Across anatomical locations throughout the body, ILCs adopt tissue-specific fates, differing from circulating ILC populations. Adaptations of ILCs to microenvironmental changes have been documented in several inflammatory contexts, including obesity, asthma, and inflammatory bowel disease. While our understanding of ILC functions within tissues have predominantly been based on mouse studies, development of advanced single cell platforms to study tissue-resident ILCs in humans and emerging patient-based data is providing new insights into this lymphocyte family. Within this review, we discuss current concepts of ILC fate and function, exploring tissue-specific functions of ILCs and their contribution to health and disease across organ systems.

Interleukin-33/ Suppression of Tumorigenicity 2 in Renal Fibrosis: Emerging Roles in Prognosis and Treatment

Chronic kidney disease (CKD) is a major public health problem that affects more than 10% of the population worldwide and has a high mortality rate. Therefore, it is necessary to identify novel treatment strategies for CKD. Incidentally, renal fibrosis plays a central role in the progression of CKD to end-stage renal disease (ESRD). The activation of inflammatory pathways leads to the development of renal fibrosis. In fact, interleukin-33 (IL-33), a newly discovered member of the interleukin 1 (IL-1) cytokine family, is a crucial regulator of the inflammatory process. It exerts pro-inflammatory and pro-fibrotic effects via the suppression of tumorigenicity 2 (ST2) receptor, which, in turn, activates other inflammatory pathways. Although the role of this pathway in cardiac, pulmonary, and hepatic fibrotic diseases has been extensively studied, its precise role in renal fibrosis has not yet been completely elucidated. Recent studies have shown that a sustained activation of IL-33/ST2 pathway promotes the development of renal fibrosis. However, with prolonged research in this field, it is expected that the IL-33/ST2 pathway will be used as a diagnostic and prognostic tool for renal diseases. In addition, the IL-33/ST2 pathway seems to be a new target for the future treatment of CKD. Here, we review the mechanisms and potential applications of the IL-33/ST2 pathway in renal fibrosis; such that it can help clinicians and researchers to explore effective treatment options and develop novel medicines for CKD patients.

Serum IL-33 as a biomarker in different diseases: useful parameter or much need for clarification?

Interleukin-33 (IL-33), a member of the IL-1 family, is critically involved in the modulation of the activity of a diverse range of immunocompetent cells. Essential roles have been implicated in cardioprotection, in both innate and adaptive immune responses in mucosal organs, and in the maintenance of adipose tissue cells. Over the past 10 years, several studies evaluated the usability of IL-33 as a biomarker in diseases of inflammatory and noninflammatory origin. Our group is currently evaluating the predictive role of serum IL-33 in acute kidney injury (AKI). The aim of the article is to discuss selected studies on IL-33 in different diseases and its potential role as a biomarker molecule.

Efficacy and safety of coronary stent intervention for coronary heart disease and its impact on short-term and long-term prognosis

OBJECTIVE

To investigate the effect of coronary stent intervention on the efficacy, safety, and short-term and long-term prognosis of patients with coronary heart disease (CHD).

METHODS

From March 2016 to November 2017, 60 cases of CHD patients receiving coronary stent interventiontherapy (research group) and 42 cases of patients receiving conventional drug therapy (control group) in our hospital were recruited as research objects. The clinical efficacy, safety and prognosis in the two groups were compared, and the levels of matrix metalloproteinase-9 (MMP-9) and interleukin-33 (IL-33) in the two groups were measured before and after treatment.

RESULTS

The clinical efficacy and prognostic quality of life of patients in the research group were higher than those in the control group (P<0.050), and the serum levels of MMP-9 and IL-33 in the research group were higher than those in the control group after treatment (P<0.050).

CONCLUSION

Compared with drug therapy alone, coronary stent intervention therapy has better clinical efficacy and short-term and long-term prognosis in treating CHD, but it is easy to promote inflammatory reaction after surgery. Therefore, attention should be paid to the control of inflammation before and after treatment.

Εndothelial and microvascular function in CKD: Evaluation methods and associations with outcomes

BACKGROUND

Cardiovascular disease is the major cause of morbidity and mortality in patients with chronic kidney disease (CKD). Endothelial dysfunction, the hallmark of atherosclerosis, is suggested to be involved pathogenetically in cardiovascular and renal disease progression in these patients.

METHODS

This is a narrative review presenting the techniques and markers used for assessment of microvascular and endothelial function in patients with CKD and discussing findings of the relevant studies on the associations of endothelial dysfunction with co-morbid conditions and outcomes in this population.

RESULTS

Venous Occlusion Plethysmography was the first method to evaluate microvascular function; subsequently, several relevant techniques have been developed and used in patients with CKD, including brachial Flow-Mediated Dilatation, and more recently, Near-Infrared Spectroscopy and Laser Speckle Contrast Analysis. Furthermore, several circulating biomarkers are commonly used in clinical research. Studies assessing endothelial function using the above techniques and biomarkers suggest that endothelial dysfunction occurs early in CKD and contributes to the target organ damage, cardiovascular events, death and progression towards end-stage kidney disease.

CONCLUSIONS

Older and newer functional methods and several biomarkers have assessed endothelial dysfunction in CKD; accumulated evidence supports an association of endothelial dysfunction with outcomes. Future research with new, non-invasive and easily applicable methods could further delineate the role of endothelial dysfunction on cardiovascular and renal disease progression in patients with CKD.

Superior prognostic value of soluble suppression of tumorigenicity 2 for the short-term mortality of maintenance hemodialysis patients compared with NT-proBNP: a prospective cohort study

Background

Both soluble suppression of tumorigenicity 2 (sST2) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are promising biomarkers associated with the adverse clinical outcomes of dialysis patients. Our research aims at exploring and comparing the roles of sST2 and NT-proBNP in predicting the short-term and long-term mortality of maintenance hemodialysis (MHD) patients.

Methods

A prospective cohort study was performed. Patients undergoing hemodialysis in July 2014 were enrolled from the Blood Purification Center of Ruijin Hospital. MHD patients were followed up for 3 years. The primary outcome was all-cause mortality at the 1-year and 3-year follow-up, while the secondary outcome was cardiovascular mortality. Serum sST2 level was detected by quantified ELISA kits. Clinical data were analyzed by SPSS 23.0 version.

Results

205 patients were recruited. The median sST2 level was 15.99 (11.60, 20.49) ng/ml. After 3 years of follow-up, both all-cause and cardiovascular mortality in 1 year and all-cause and cardiovascular mortality in 3 years increased significantly with serum sST2. For short-term mortality, no significant difference was observed in patients with increasing NT-proBNP levels. Cox regression analysis indicated that only sST2 was independent in predicting the risk of short-term outcomes. For long-term mortality, both sST2 and NT-proBNP were independent risk factors, while a higher hazard ratio was observed for NT-proBNP.

Conclusions

Serum sST2 is a novel biomarker associated with adverse clinical outcomes in MHD patients. It was significant for both all-cause and cardiovascular mortality in MHD patients and may provide better prognostic value in short-term prognosis than the classic biomarker NT-proBNP.

Prognostic Value of Soluble Suppression of Tumorigenicity 2 in Chronic Kidney Disease Patients: A Meta-Analysis

Objective

Previous studies have controversial results about the prognostic role of soluble suppression of tumorigenicity 2 (sST2) in chronic kidney disease (CKD). Therefore, we conduct this meta-analysis to access the association between sST2 and all-cause mortality, cardiovascular disease (CVD) mortality, and CVD events in patients with CKD.

Methods

The publication studies on the association of sST2 with all-cause mortality, CVD mortality, and CVD events from PubMed and Embase were searched through August 2020. We pooled the hazard ratio (HR) comparing high versus low levels of sST2 and subgroup analysis based on treatment, continent, and diabetes mellitus (DM) proportion, and sample size was also performed.

Results

There were 15 eligible studies with 11,063 CKD patients that were included in our meta-analysis. Elevated level of sST2 was associated with increased risk of all-cause mortality (HR 2.05; 95% confidence interval (CI), 1.51-2.78), CVD mortality (HR 1.68; 95% CI, 1.35-2.09), total CVD events (HR 1.88; 95% CI, 1.26-2.80), and HF (HR 1.35; 95% CI, 1.11-1.64). Subgroup analysis based on continent, DM percentage, and sample size showed that these factors did not influence the prognostic role of sST2 levels to all-cause mortality.

Conclusions

Our results show that high levels of sST2 could predict the all-cause mortality, CVD mortality, and CVD events in CKD patients.

Matrix metalloproteinase 3 regulates angiotensin II‑induced myocardial fibrosis cell viability, migration and apoptosis

Angiotensin II (AngII) is a central signaling molecule of the renin-angiotensin system that serves a vital role in myocardial fibrosis (MF). The present study aimed to investigate the effects of matrix metalloproteinase (MMP)3 on MF progression. To induce cellular fibrosis, H9C2 rat myocardial cells were treated with AngII for 24 h. Subsequently, cells were treated with levocarnitine, or transfected with small interfering (si)RNA-negative control or siRNA-MMP3 (1/2/3). Cell viability, apoptosis and migration were assessed by performing Cell Counting Kit-8, flow cytometry and Transwell assays, respectively. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting were performed to determine the expression levels of MF biomarkers, including disease-, apoptosis- and oxidative stress-related genes. Compared with the control group, AngII significantly inhibited H9C2 cell viability and migration, and significantly increased H9C2 cell apoptosis (P<0.05). However, compared with AngII-treated H9C2 cells, MMP3 knockdown significantly inhibited fibrotic H9C2 cell viability and migration, but increased fibrotic H9C2 cell apoptosis (P<0.05). The RT-qPCR results demonstrated that MMP3 knockdown significantly downregulated the expression levels of AXL receptor tyrosine kinase, AngII receptor type 1, α-smooth muscle actin and Collagen I in AngII-treated H9C2 cells (P<0.05). Moreover, compared with AngII-treated cells, MMP3 knockdown significantly decreased Bcl-2 expression levels, but significantly increased caspase-3 and p53 expression levels in AngII-treated cells (P<0.05). Additionally, compared with AngII-treated cells, MMP3 knockdown significantly decreased MMP3, MMP9, STAT3, p22Phox and p47Phox expression levels in AngII-treated cells (P<0.05). The present study indicated that MMP3 knockdown altered myocardial fibroblast cell viability, migration and apoptosis by regulating apoptosis- and oxidative stress-related genes, thus delaying MF progression.

Assessment of Endothelial and Microvascular Function in CKD: Older and Newer Techniques, Associated Risk Factors, and Relations with Outcomes

BACKGROUND

Endothelium is the inner cellular lining of the vessels that modulates multiple biological processes including vasomotor tone, permeability, inflammatory responses, hemostasis, and angiogenesis. Endothelial dysfunction, the basis of atherosclerosis, is characterized by an imbalance between endothelium-derived relaxing factors and endothelium-derived contracting factors.

SUMMARY

Starting from the semi-invasive venous occlusion plethysmography, several functional techniques have been developed to evaluate microvascular function and subsequently used in patients with CKD. Flow-mediated dilatation of the forearm is considered to be the "gold standard," while in the last years, novel, noninvasive methods such as laser speckle contrast imaging and near-infrared spectroscopy are scarcely used. Moreover, several circulating biomarkers of endothelial function have been used in studies in CKD patients. This review summarizes available functional methods and biochemical markers for the assessment of endothelial and microvascular function in CKD and discusses existing evidence on their associations with comorbid conditions and outcomes in this population. Key Messages: Accumulated evidence suggests that endothelial dysfunction occurs early in CKD and is associated with target organ damage, progression of renal injury, cardiovascular events, and mortality. Novel methods evaluating microvascular function can offer a detailed, real-time assessment of underlying phenomena and should be increasingly used to shed more light on the role of endothelial dysfunction on cardiovascular and renal disease progression in CKD.

The role of interleukin-1 family members in hyperuricemia and gout

BACKGROUND

Interleukin (IL)-1 family cytokines and their receptors have important roles in innate and partly in adaptive immunity. The family consists of 11 members of which IL-1α, IL-1β, IL-18, IL-33, IL-36α, IL-36β and IL-36γ are considered pro-inflammatory and IL-1Ra, IL-36Ra, IL-37 and IL-38 anti-inflammatory. Whereas IL-1β has a known pivotal role in gout, increasing evidence suggests other IL-1 family members are also involved in the pathogenesis of hyperuricemia and gout flares.

FINDINGS

Studies indicate IL-1α, like IL-1β, plays an essential role in the pathogenesis of gout flares. IL-18, although elevated in patients with gout, does not contribute to MSU crystal-induced inflammation, but may be involved in the subsequent development of cardiovascular disease in individuals with gout. The role of the pro-inflammatory cytokine IL-36 in gout remains elusive. In contrast, IL-1Ra, IL-33, IL-37 and IL-38 inhibit MSU crystal-induced inflammation and therefore have therapeutic potential for treatment of gout flares. In addition to existing IL-1β blockers, several new therapeutics to treat gout are being developed either inhibiting the transcription or maturation of IL-1β.

CONCLUSION

In this review, IL-1 family cytokines are discussed in the context of hyperuricemia and gout. Finally, current and novel therapeutic options for targeting IL-1 are reviewed.

Cardiovascular disease risk assessment in patients with familial Mediterranean fever related renal amyloidosis

Chronic inflammation and proteinuria is a risk factor for cardiovascular disease (CVD) in patients with chronic kidney diseases and rheumatologic disorders. Our aim was to investigate the CVD events (CVDEs) and survival between the patients with FMF-related AA amyloidosis and glomerulonephropathies (GN) to define possible predictors for CVDEs. A prospective follow-up study with FMF-amyloidosis and glomerulonephropathy (GN) was performed and patients were followed for CVDEs. Flow-mediated dilatation (FMD), FGF-23, serum lipid, hsCRP levels, BMI and HOMA were assessed. A Cox regression analysis was performed to evaluate the risk factors for CVDEs. There were 107 patients in the FMF-amyloidosis group and 126 patients with GN group. Forty-seven CVDEs were observed during the 4.2-years follow up; all 28 patients in the FMF-amyloidosis group and 14/19 patients with GN developed CVDEs before the age of 40 (p = 0.002). CVD mortality was 2.8 times higher (95% CI 1.02–7.76) in patients with FMF-amyloidosis. Across both groups, FMD and FGF23 (p < 0.001) levels were independently associated with the risk of CVDEs. Patients with FMF-amyloidosis are at increased risk of early CVDEs with premature mortality age. FGF 23, FMD and hsCRP can stratify the risk of early CVD in patients with FMF-related AA amyloidosis.

Monocyte counts are negatively associated with ankle-brachial index values in non-dialysis-dependent chronic kidney disease patients

Our aim was to determine which leukocyte subtypes are most relevant to ankle-brachial index (ABI) values in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). The study included 79 NDD-CKD patients aged 62.84 ± 12.09 years (63.33% men; 26.67% patients with diabetes) and 21 age-matched normal controls. According to the estimated glomerular filtration rate (eGFR) calculated by the CKD-Epidemiology Collaboration equation (CKD-EPI), we classified the study population into 2 groups (21 subjects with NDD-CKD with an eGFR 60–89 mL/min/1.73m², 58 subjects with NDD-CKD with eGFR <60 mL/min/1.73 m²). ABI was calculated as the ratio of the ankle systolic BP divided by the arm systolic BP using an ABI-form device. An automated hematologic analyzer was used to measure total and differential leukocyte counts. Monocyte counts and monocyte-to-total leukocyte count ratios (MTR) in patients with an ABI value <1.10 were significantly higher than those in patients with an ABI value ≥1.10, respectively. Univariate analyses revealed that mean ABI values were negatively correlated with monocyte count (r= −0.341; p = 0.044), MTR (r= −0.346, p = 0.031). Multivariate linear regression analyses showed that monocyte count was negatively associated with ABI values (β ± SE = −1.825 ± 0.341, p = 0.013). The area under the curve of monocyte counts was 0.695 (95% confidence interval 0.586–0.804, p = 0.002) in predicting an ABI value <1.10. Monocyte counts are negatively associated with ABI values in patients with NDD-CKD without apparent peripheral arterial occlusive disorder (PAOD).

Prognostic value of soluble ST2 and soluble LR11 on mortality and cardiovascular events in peritoneal dialysis patients

Background

Although the soluble form of suppression of tumorigenicity 2 (sST2) and soluble low-density lipoprotein receptor relative with 11 ligand-binding repeats (sLR11) have emerged as novel cardiovascular biomarkers in patients with cardiovascular disease, their prognostic value has not been fully investigated in peritoneal dialysis (PD) patients.

Methods

We included 74 prevalent PD patients from a prospective cohort and measured serum sST2 and sLR11 concentrations by an enzyme-linked immunosorbent assay. The association of these biomarkers and all-cause mortality and major adverse cardiac and cerebrovascular events (MACCEs) was evaluated.

Results

During a follow-up of 38.5 months, all-cause deaths and MACCEs were observed in 13 (17.6%) patients and 23 (31.3%) patients. Multivariable Cox analyses demonstrated that greater sST2 was independently associated with higher risk of all-cause mortality (≥75.8 ng/mL; hazard ratio [HR] = 5.551; 95% confidence interval [CI] = 1.360–22.660) and MACCEs (≥72.5 ng/mL; HR = 4.609; 95% CI = 1.608–13.208). Furthermore, sST2 showed additive predictive value for mortality to the base model including traditional risk factors (net reclassification index = 0.598, P = 0.04). sLR11 was not significantly associated with all-cause mortality or MACCE.

Conclusions

sST2, but not sLR11, indicated a significant prognostic value for all-cause mortality and cardiovascular events in PD patients. Further research is needed to validate emerging biomarkers in these populations.

The concentration of interleukin-33 in heart failure with reduced ejection fraction

Objective:

Despite several improvements in the management of heart failure (HF), it is still an incurable and a progressive disease. Several trials demonstrated that the process of inflammation may be responsible for initiation and progression of HF. The aim of the present study was to investigate the role of interleukin-33 (IL-33) in the pathogenesis of HF and to assess whether disease etiology and course of the disease affect the expression of cytokines.

Methods:

The study included 155 (106 male and 49 female) patients with systolic HF with a mean left ventricle ejection fraction of 32.13±12.8% and 60 (36 male and 24 female) healthy individuals. IL-33 concentrations were evaluated using enzyme-linked immunosorbent assay.

Results:

The concentration of IL-33 was statistically significantly lower in patients with HF than in healthy subjects, 16.91 (0–81.00) pg/mL and 92.51 (33.61–439.61) pg/mL, respectively. Patients with HF with ischemic etiology had lower concentration of IL-33 (10.75 pg/mL) than subjects with HF with non-ischemic etiology (21.05 pg/mL). Patients with stable HF (10.46 pg/mL) had lower IL-33 levels than those with unstable HF (19.02 pg/mL).

Conclusion:

The concentrations of IL-33 were lower in patients with HF than in healthy controls, which may play an important role of above cytokine in HF development and progression. In addition, interleukin concentrations varied depending on the etiology and severity of the course of the disease.

Changes in FGF-23, Neutrophil/Platelet Activation Markers, and Angiogenin in Advanced Chronic Kidney Disease and Their Effect on Arterial Stiffness

AIMS

The aims of this study were to measure changes in fibroblast growth factor 23 (FGF-23), neutrophil (elastase, lactoferrin)/platelet activation marker (mean platelet volume-to-platelet count ratio [MPR]), and angiogenin according to the stage of chronic kidney disease (CKD), and to evaluate the association of FGF-23, elastase, lactoferrin, MPR, and angiogenin with arterial stiffness using brachial-ankle pulse wave velocity (ba-PWV) in CKD patients.

METHODS

According to the estimated glomerular filtration rate (eGFR) calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, the patients were allocated to five groups: (1) normal controls (eGFR ≥90 mL/min/1.73 m2 without pathologic, urine [proteinuria], blood [electrolyte], and imaging abnormalities; n = 22); (2) CKD stage 2 (eGFR 60-89 mL/min/1.73 m2; n = 17); (3) CKD stage 3 (eGFR 30-59 mL/min/1.73 m2; n = 22); (4) CKD stage 4 (eGFR 15-30 mL/min/1.73 m2; n = 17); and (5) CKD stage 5-hemodialysis (HD) (n = 30). All the patients were free of clinically apparent cardiovascular disease. Serum FGF-23, elastase, lactoferrin, and angiogenin concentrations and the MPR were measured to study the association of the above parameters with the clinical (age, sex, presence of diabetes mellitus, and blood pressure), biochemical (calcium, phosphorus, uric acid, intact parathyroid hormone [PTH], low-density lipoprotein cholesterol, and high-sensitivity C-reactive protein), and ba-PWV values of the CKD patients.

RESULTS

(1) The mean ba-PWV values were 1,497.2 ± 206.4 cm/s in the controls, 1,649.0 ± 247.9 cm/s in the CKD stage 2 group (p < 0.05 vs. controls), 1,655.8 ± 260.3 cm/s in the CKD stage 3 group (p < 0.05 vs. controls), 1,823.0 ± 402.4 cm/s in the CKD stage 4 group (p < 0.05 vs. controls and CKD stages 2 and 3), and 1,905.2 ± 374.1 cm/s in the CKD stage 5-HD group (p < 0.05 vs. controls and CKD stage 2). (2) The mean log10(FGF-23) concentration values were 0.77 ± 0.27, 0.97 ± 0.48, 1.10 ± 0.35 (p < 0.05 vs. controls and CKD stage 2), 1.35 ± 0.48 (p < 0.05 vs. controls and CKD stages 2 and 3), and 2.12 ± 0.82 (p < 0.05 vs. controls and CKD stages 2-4); the mean angiogenin levels were 230.6 ± 70.5 pg/mL, 283.0 ± 53.5 pg/mL (p < 0.05 vs. controls), 347.3 ± 76.9 pg/mL (p < 0.05 vs. controls and CKD stage 2), 445.9 ± 90.6 pg/mL (p < 0.05 vs. controls and CKD stages 2 and 3), and 370.9 ± 142.4 pg/mL (p < 0.05 vs. controls and CKD stages 2 and 3). (3) In the stage 3-4 CKD/HD patients, the mean elastase-to-neutrophil and lactoferrin-to-neutrophil ratios were significantly lower than in the controls and the stage 2 CKD patients. (4) Our multivariate linear regression analyses showed that age, pulse pressure, mean arterial pressure, PTH, and FGF-23 were independently associated with ba-PWV values.

CONCLUSIONS

Circulating FGF-23 and angiogenin concentrations gradually increased as CKD advanced, whereas neutrophil activation markers were significantly lower in the stage 3-4 CKD/HD patients than in the controls and stage 2 CKD patients. FGF-23 was weakly associated with ba-PWV values in patients with CKD/HD and no previous cardiovascular disease.

Complement-mediated thrombotic microangiopathy as a link between endothelial damage and steroid-refractory GVHD

Transplant-associated thrombotic microangiopathy (TA-TMA), a complication of hematopoietic cell transplant (HCT), is associated with significant morbidity and mortality. The pathophysiology and overlap of TA-TMA with other posttransplant complications such as graft-versus-host disease (GVHD) is poorly understood. We retrospectively identified cases of TA-TMA among patients with grade 3/4 gastrointestinal (GI) GVHD, reviewed intestinal biopsy specimens, and performed correlative testing of biomarkers associated with TA-TMA. TA-TMA was more common in patients with steroid-refractory GVHD compared with steroid-responsive GVHD (79.3% vs 42.1%; P = .001). Among patients surviving 100 days post-HCT, 1-year survival from day 100 was significantly better for patients who had not developed TA-TMA in the first 100 days (69.5% vs 36.7%; P < .001). Only 1 of 7 proposed TA-TMA histology criteria (mucosal hemorrhage) differed significantly based on GVHD steroid response. In multivariable modeling, steroid-refractory GVHD was a risk factor for development of TA-TMA (hazard ratio, 3.09; 95% confidence interval, 1.68-5.67; P < .001). There were no differences in complement activation at GVHD onset; however, 2 to 6 weeks later, patients with TA-TMA had higher levels of BBPlus and C5b-9, markers of alternative and terminal pathway activation (BBPlus: median, 600 vs 209.3 ng/mL; P = .0045) (C5b-9: median, 425.9 vs 258.4 ng/mL; P = .029). TA-TMA is associated with poor overall survival (OS) following HCT and may be detected early by histologic findings and may be differentiated from GVHD by measurement of alternative and terminal complement pathway activation. It is unknown whether treatment of TA-TMA will improve survival in steroid-refractory GVHD.

Gastrointestinal Microbiota in Patients with Chronic Kidney Disease: A Systematic Review

Emerging evidence suggests that gastrointestinal (GI) microbiota dysbiosis is associated with chronic kidney disease (CKD) and metabolite concentrations. The purpose of this systematic review was to evaluate and contextualize the research characterizing GI microbiota in patients with CKD. We searched for full-text, peer-reviewed, English studies in PubMed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and Google Scholar using a combination of MeSH terms and keywords. Eleven of the 20 studies examined GI microbiota in patients with CKD, and 9 studies focused on the effect of interventions on GI microbiota or metabolites. Available data characterizing GI microbiota in patients with CKD suggest a decline in saccharolytic bacteria and an increase in fermenters of nitrogen-containing compounds, serving as a source for circulating uremic toxins. However, studies examined limited sets of predetermined microbes, which do not reflect the entire GI microbial community and its influence on host physiology. We recommend further studies examining the entire microbial community and the potential role in regulating host physiology in CKD.

Factors which Influence the Levels of ST-2, Galectin-3 and MMP-9 in Acute Coronary Syndrome

BACKGROUND

Several cardiac biomarkers are being studied to explore their potential in the prognostication of Acute Coronary Syndrome (ACS). However, there are limited studies exploring the relationship between these biomarkers and clinical, laboratory and demographic characteristics.

OBJECTIVE

We sought to determine the factors which influence the concentration of novel cardiac biomarkers such as Galectin-3, suppression of tumorigenicity-2 (ST-2) and Matrix Metallopeptidase-9 (MMP-9) in patients with ACS.

METHODS

A total of 122 patients with ACS were enrolled in the study. The study patients were categorized into two groups namely: STEMI (n=58) and NSTEMI/UA (n=64). Plasma samples were used to determine the level of biomarkers, Galectin-3 and ST-2, and serum samples were used to determine the levels of MMP-9 using the Enzyme-linked immunosorbent assay (ELISA). The association between the plasma and serum levels of biomarkers and, demographic, clinical and laboratory variables were determined. Statistical analyses for the study were performed using SPSS 16.0 software (SPSS Inc., Chicago, IL, USA).

RESULTS

Elderly aged [0.107 (0.012-0.969); p=0.047] patients had higher ST-2. Galectin-3 was higher among female patients [3.693(1.253-10.887); p=0.018] and patients with low left ventricular ejection fraction [2.882 (1.041-7.978); p=0.042]. Patients with lower body mass index [3.385 (1.241-9.231); p=0.017], diabetes [3.650 (1.302-10.237); p=0.014] and high total leukocyte count [2.900 (1.114-7.551; p=0.029] had higher MMP-9 levels.

CONCLUSION

The concentration of galectin-3, ST-2 and MMP-9 are independently influenced by demographic, clinical and laboratory characteristics. It is estimated that these factors should be accounted for when interpreting the results of the biomarker assays.

ST2 blockade mitigates peritoneal fibrosis induced by TGF-β and high glucose

Peritoneal fibrosis (PF) is an intractable complication of peritoneal dialysis (PD) that leads to peritoneal membrane failure. This study investigated the role of suppression of tumorigenicity (ST)2 in PF using patient samples along with mouse and cell‐based models. Baseline dialysate soluble (s)ST2 level in patients measured 1 month after PD initiation was 2063.4 ± 2457.8 pg/mL; patients who switched to haemodialysis had elevated sST2 levels in peritoneal effluent (1576.2 ± 199.9 pg/mL, P = .03), which was associated with PD failure (P = .04). Baseline sST2 showed good performance in predicting PD failure (area under the receiver operating characteristic curve = 0.780, P = .001). In mice with chlorhexidine gluconate‐induced PF, ST2 was expressed in fibroblasts and mesothelial cells within submesothelial zones. In primary cultured human peritoneal mesothelial cells (HPMCs), transforming growth factor‐β treatment increased ST2, fibronectin, β‐galactosidase and Snail protein levels and decreased E‐cadherin level. Anti‐ST2 antibody administration reversed the up‐regulation of ST2 and fibronectin expression; it also reduced fibrosis induced by high glucose (100 mmol/L) in HPMCs. Thus, high ST2 level in dialysate is a marker for fibrosis and inflammation during peritoneal injury, and blocking ST2 may be an effective therapeutic strategy for renal preservation.

The Confounding Effects of Non-cardiac Pathologies on the Interpretation of Cardiac Biomarkers

PURPOSE OF REVIEW

Cardiac biomarkers play important roles in routine evaluation of cardiac patients. But while these biomarkers can be extremely valuable, none of them should ever be used by themselves-without adding the clinical context. This paper explores the non-cardiac pathologies that can be seen with the cardiac biomarkers most commonly used.

RECENT FINDINGS

High-sensitivity troponin assay gained FDA approval for use in the USA, and studies demonstrated its diagnostic utility can be extended to patients with renal impairment. Gender-specific cut points may be utilized for high-sensitivity troponin assays. In the realm of the natriuretic peptides, studies demonstrated states of natriuretic peptide deficiency in obesity and in subjects of African-American race. Regardless, BNP and NT-proBNP both retained prognostic utilities across a variety of comorbid conditions. We are rapidly gaining clinical evidence with use of soluble ST2 and procalcitonin levels in management of cardiac disease states. In order to get the most utility from their measurement, one must be aware of non-cardiac pathologies that may affect the levels of biomarkers as although many of these are actually true values, they may not represent the disease we are trying to delineate. A few take-home points are as follows: 1. A biomarker value should never be used without clinical context 2. Serial sampling of biomarkers is often helpful 3. Panels of biomarkers may be valuable.

Dysregulated Th1 Immune and Vascular Responses in Scrub Typhus Pathogenesis

Scrub typhus is an emerging, insect-transmitted disease caused by Orientia tsutsugamushi, a Gram- and LPS-negative bacterium that replicates freely within professional phagocytes and endothelial cells. Scrub typhus is prevalent with high mortality rates, but information regarding its molecular pathogenesis, microbial virulence determinants, and key immune responses is limited. Improved animal models have recently been developed that respectively resemble the pathological features of self-limiting or severe scrub typhus in humans. Strong activation of Th1 and CD8, but not Th2 and regulatory T, immune responses, accompanied by altered angiopoietin/Tie2-related regulation, are hallmarks of lethal infection in murine models. This review, based primarily on recent advances from clinical and experimental studies, highlights tissue- and endothelial cell-specific biomarkers that are indicative of immune dysregulation. The potential roles of neutrophils and damage-associated molecular pattern molecules at late stages of disease are discussed in the context of vascular leakage, pulmonary and renal injury, and scrub typhus pathogenesis.

IL33/ST2 Axis in Diabetic Kidney Disease: A Literature Review

Interleukin-33 (IL-33) is a cytokine belonging to the IL-1 family, playing a role in inflammatory, infectious and autoimmune diseases and expressed in the cellular nucleus in several tissues. High levels of IL-33 are expressed in epithelial barrier tissues and endothelial barriers. ST2 is a receptor for IL-33, expressed selectively on a subset of Th2 cells, mediating some of their functions. The IL-33/ST2 axis plays an important role in several acute and chronic inflammatory diseases, including asthma and rheumatoid arthritis. Different disorders are related to the activity of IL-33, ST2, or their axis, including cardiovascular disease or renal disturbances. Therefore, in the present work, a literature review was conducted, covering the period from 1 January 2000 to 30 November 2018, in PubMed, ScienceDirect, and Google Scholar database, to assess the involvement of the IL-33/ST2 axis in diabetic kidney disease. 6 articles directly dealing with the argument were identified, highlighting a clear link between IL-33/ST2 axis and diabetic kidney disease or related nephropathy. Overall, the involvement of ST2 seems to be more predictive than IL-33, especially in investigating the deterioration of kidney function; however, both compounds are pivotal in the field of renal diseases. Future studies are required to confirm the scientific evidences on larger and more heterogeneous cohorts.

sST2 as a New Biomarker of Chronic Kidney Disease-Induced Cardiac Remodeling: Impact on Risk Prediction

Heart failure is the most frequent cardiac complication of chronic kidney disease (CKD). Biomarkers help identify high-risk patients. Natriuretic peptides (BNP and NT-proBNP) are largely used for monitoring patients with cardiac failure but are highly dependent on glomerular filtration rate (GFR). Soluble suppression of tumorigenicity 2 (sST2) biomarker is well identified in risk stratification of cardiovascular (CV) events in heart failure. Furthermore, sST2 is included in a bioclinical score to stratify mortality risk. The aims of this study were to evaluate (i) the interest of circulating sST2 level in heart dysfunction and (ii) the bioclinical score (Barcelona Bio-Heart Failure risk calculator) to predict the risk of composite outcome (major adverse coronary events) and mortality in the CKD population. A retrospective study was carried out on 218 CKD patients enrolled from 2004 to 2015 at Montpellier University Hospital. sST2 was measured by ELISA (Presage ST2® kit). GFR was estimated by the CKD-EPI equation (eGFR). Indices of cardiac parameters were performed by cardiac echography. No patient had reduced ejection fraction. 112 patients had left ventricular hypertrophy, and 184 presented cardiac dysfunction, with structural, functional abnormalities or both. sST2 was independent of age and eGFR (ρ = 0.05, p = 0.44, and ρ = −0.07, p = 0.3, respectively). Regarding echocardiogram data, sST2 was correlated with left ventricular mass index (ρ = 0.16, p = 0.02), left atrial diameter (ρ = 0.14, p = 0.04), and volume index (ρ = 0.13, p = 0.05). sST2 alone did not change risk prediction of death and/or CV events compared to natriuretic peptides. Included in the Barcelona Bio-Heart Failure (BCN Bio-HF) score, sST2 added value and better stratified the risk of CV events and/or death in CKD patients (p < 0.0001). To conclude, sST2 was associated with cardiac remodeling independently of eGFR, unlike other cardiac biomarkers. Added to the BCN Bio-HF score, the risk stratification of death and/or CV events in nondialyzed CKD patients was highly improved.

Does neutrophyl to lymphocyte ratio really predict chronic kidney disease progression?

PURPOSE

Chronic kidney disease (CKD) is an inflammatory process. In addition to increased morbidity and mortality, inflammation also contributes to the progression of CKD. Neutrophil/lymphocyte ratio (NLR) is a marker of inflammation. Some recent data suggest that NLR may predict the progression of CKD.

METHODS

In this study, 5-year data of 740 patients with stage 2-4 CKD were reviewed retrospectively. Demographic data, NLR, CRP, albumin, the amount of proteinuria were recorded. At the beginning and the end of follow-up the glomerular filtration rate (GFR) and the annual GFR decline rate were calculated. Patients were divided to high and low NLR group according to median value of their baseline NLR. Reaching stage 5 CKD or initiation of renal replacement therapy was determined as end-point for follow-up.

RESULTS

The mean age was 62.8 ± 0.57 years, eGFR 40 ml/min/1.73 m², median NLR was 2.76. NLR increased as the CKD-stage increased. Mean follow-up time was 51.2 ± 30 months and 21.4% of patients reached the end-point. NLR was significantly increased at follow-up (from 3.22 to 5.68, p < 0.001). Annual GFR loss and baseline CRP were higher but baseline albumin and GFR were lower of patients with high NLR. The percent of patients reaching the end-point was not different between the groups with high and low baseline NLR. Kaplan Meier analysis showed that patients with high NLR had significantly lower mean renal survival (86.5 months) than patients with low NLR (105 months) (p < 0.001). In the Cox-regression analysis NLR was not an independent predictor in reaching the end-point but presence of diabetes mellitus, younger age and low baseline eGFR were found effective.

CONCLUSIONS

NLR is an indicator of inflammation in chronic kidney disease. It may not be an independent predictor of CKD progression except that the CKD is in a more advanced stage and reflects the associated inflammation. Classical risk factors such as DM and lower GFR are more powerful predictors of progression.

Neutrophil Elastase Inhibitors and Chronic Kidney Disease

End-stage renal disease (ESRD), the last stage of chronic kidney disease (CKD), is characterized by chronic inflammation and oxidative stress. Neutrophils are the front line cells that mediate an inflammatory response against microorganisms as they can migrate, produce reactive oxygen species (ROS), secrete neutrophil serine proteases (NSPs), and release neutrophil extracellular traps (NETs). Serine proteases inhibitors regulate the activity of serine proteases and reduce neutrophil accumulation at inflammatory sites. This review intends to relate the role of neutrophil elastase in CKD and the effects of neutrophil elastase inhibitors in predicting or preventing inflammation.

Inflammation and renal fibrosis: Recent developments on key signaling molecules as potential therapeutic targets

Chronic kidney disease (CKD) is a major public health issue. At the histological level, renal fibrosis is the final common pathway of progressive kidney disease irrespective of the initial injury. Considerable evidence now indicates that renal inflammation plays a central role in the initiation and progression of CKD. Some of the inflammatory signaling molecules involved in CKD include: monocyte chemoattractant protein-1 (MCP-1), bradykinin B₁ receptor (B₁R), nuclear factor κB (NF-κB), tumor necrosis factor-α (TNFα), transforming growth factor β (TGF-β), and platelet-derived growth factor (PDGF). Multiple antifibrotic factors, such as interleukin-10 (IL-10), interferon-γ (IFN-γ), bone morphogenetic protein-7 (BMP-7), hepatocyte growth factor (HGF) are also downregulated in CKD. Therefore, restoration of the proper balance between pro- and antifibrotic signaling pathways could serve as a guiding principle for the design of new antifibrotic strategies that simultaneously target many pathways. The purpose of this review is to summarize the existing body of knowledge regarding activation of cytokine pathways and infiltration of inflammatory cells as a starting point for developing novel antifibrotic therapies to prevent progression of CKD.