Investigation of salivary C-reactive protein and interleukin-18 for the diagnosis of neonatal sepsis

BACKGROUND

Neonatal sepsis is a leading cause of death in neonates worldwide. The investigation of biomarkers for the early diagnosis of neonatal sepsis is in progress with controversial outcomes. The current report aims to evaluate the values of salivary C-reactive protein (CRP) and interleukin-18 (IL-18) for the diagnosis of neonatal sepsis.

MATERIALS AND METHODS

In this cross-sectional study, 89 neonates, including 49 neonatal septic case and 40 healthy group admitted at the neonatal intensive care unit, were evaluated. The salivary samples of IL-18 and CRP were measured before the antibiotic therapy initiation, as soon as blood samplings. Sepsis diagnosis was confirmed by the positive blood culture. The diagnostic values of the biomarkers were determined using the receiver operating characteristic curve (ROC curve) analysis. Besides, the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic accuracy were measured.

RESULTS

Salivary CRP level was remarkably higher in septic case than healthy group (5.2 ± 4.61 vs. 3.5 ± 1.7; P = 0.02), while salivary IL-18 was not different between the groups (0.1 ± 0.29 vs. 0.04 ± 0.19; P = 0.25). The ROC curve for IL-18 showed insignificant values (P = 0.37). The ROC curve of salivary CRP showed area under the curve of 0.63 (95% confidence interval: 0.51-0.74; P = 0.03) with the sensitivity, specificity, PPV, NPV, LR+, LR - and diagnostic accuracy of 44.9% (31.8-58.7), 80% (65.2-89.5), 73.3% (55.5-85.82), 54.2% (41.6-66.3), 60.6% (50.29-70.18), 2.24 (1.57-3.2), and 0.68 (0.63-0.75) at the cutoff of 4.55 ng/L, respectively.

CONCLUSION

Based on the findings of the current study, salivary CRP can be considered a biomarker for the early diagnosis of neonatal sepsis, while no statistical values for salivary IL-18 were detected. Due to the significance of neonatal sepsis, further evaluations are strongly recommended.

Interleukin-18 Plays a Positive Feedback Activity to Natural Killer-Like B Cells in Hepatitis B Virus-Associated Acute-on-Chronic Liver Failure

Natural killer-like B (NKB) cells are a newly identified immune subset, which are separated from NK cells and B cells. NKB cells demonstrated immunoregulatory functions in elimination of microbial infection and inflammation through secretion of interleukin (IL)-12 and IL-18. However, the role of NKB cells in hepatitis B virus (HBV)-related diseases has not been reported. In this study, peripheral T cells, B cells, NK cells, and NKB cells in HBV-associated acute-on-chronic liver failure (ACLF), chronic hepatitis B (CHB), asymptomatic HBV carriers (AsC), and controls were investigated by flow cytometry. Plasma IL-12 and IL-18 levels were measured by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells from HBV-ACLF patients were stimulated with recombinant IL-12 or IL-18. Changes of immune cell percentage and nuclear factor-kappa B (NF-κB) phosphorylation were assessed. There were no statistical differences of T cell percentage, B cell percentage, or NK cell percentage among groups. NKB cell percentage within lymphocytes, and plasma IL-12 and IL-18 levels in HBV-ACLF patients were significantly elevated compared with in CHB, AsC, and controls. NKB cell percentage and IL-18, but not IL-12, had a better prognosis function for the 28-day survival status in HBV-ACLF patients. Recombinant IL-12 enhanced T cell and NK cell percentage, while only high concentrations (10 ng/mL) of IL-18 promoted NKB cell percentage in HBV-ACLF patients. High concentrations (10 ng/mL) of IL-18 induced NF-κB phosphorylation in NKB cells probably through suppression of IL-18 binding protein in HBV-ACLF patients. The current data indicated that elevated NKB cells and IL-18 might be important indicators for poor prognosis of HBV-ACLF patients. Increased IL-18 might play a positive feedback activity to NKB cells in HBV-ACLF patients.

Adult-Onset Still's Disease Complicated by Immunoglobulin A Vasculitis and anti-CCP Antibody-Positive Arthritis

A 38-year-old male was admitted to our hospital for arthralgia, fever, skin rash, and purpura. He was diagnosed as having adult-onset Still's disease (AOSD) based on Yamaguchi's criteria. Skin biopsy revealed immunoglobulin A (IgA) vasculitis. He was also found to have anti-cyclic citrullinated peptide (CCP) antibody-positive inflammatory arthritis on a shoulder joint, however he did not fulfill classification criteria for rheumatoid arthritis. Elevated serum cytokine such as serum IL-18 supported the diagnosis of AOSD. His symptoms improved with 40 mg of prednisolone plus cyclosporin A (200 mg/day). Two years after hospitalization, AOSD was relapsed with pleurisy and hyperferritinemia. Finally, he was diagnosed with multicyclic systemic type of AOSD complicated by IgA vasculitis and seropositivity of anti-CCP antibody. Clinicians need to consider the complication of multiple rheumatic diseases, even if the disease-specific autoantibody is positive.

The risk of atopic dermatitis may be affected by IL-1B +3954 C/T and IL-18 -137G/C polymorphisms: evidence from a meta-analysis

Introduction

Whether Th1-related cytokine polymorphisms influence the risk of atopic dermatitis (AD) remain inconclusive.

Aim

The authors performed a meta-analysis to robustly explore relationships between Th1-related cytokine polymorphisms and the risk of AD by merging the results of eligible publications.

Material and methods

The authors strictly adhere to the PRISMA guidelines in study design and implementation. A thorough literature search in Medline, Embase, Wanfang, VIP and CNKI was performed by the authors to identify eligible publications. Relationships between TNF-α/IL-1/IL-6/IL-18 polymorphisms and the risk of AD were estimated with odds ratio and its 95% confidence interval. The statistically significant p value was set at 0.05. The quality of eligible publications was assessed by the Newcastle-Ottawa scale (NOS).

Results

In total twenty-one publications with a NOS score of 7-8 were selected for merged quantitative analyses. We have noticed that genotypic frequencies of IL-1B +3954 C/T and IL-18 -137G/C polymorphisms among cases with AD and population-based controls differed significantly. Moreover, we have found that genotypic frequency of IL-1B +3954 C/T polymorphism among cases with AD and population-based controls of Caucasian origin differed significantly, and genotypic frequency of IL-18 -137G/C polymorphism among cases with AD and population-based controls of both Caucasian and Asian origins also differed significantly. However, we did not observe such genotypic distribution differences for TNF-α -238 G/A, TNF-α -308 G/A, IL-1A -889 C/T, IL-1B −511 C/T and IL6 -174 G/C polymorphisms.

Conclusions

The present meta-analysis shows that IL-1B +3954 C/T and IL-18 -137G/C polymorphisms may affect the risk of AD.

Long Non-Coding RNA NEAT1 Knockdown Alleviates Rheumatoid Arthritis by Reducing IL-18 through p300/CBP Repression

Rheumatoid arthritis (RA) is chronic inflammatory autoimmune disease. The crucial role of long non-coding RNA (lncRNA) in the progression of RA has been highlighted. Hence, this study was designed to explore the specific downstream mechanism of lncRNA nuclear-enriched abundant transcript 1 (NEAT1) in RA. Initially, the expression of NEAT1, p-p65, p300, and IL-18 in clinical tissues and cells was determined. Then, interactions among p65, NEAT1, p300, CBP, and IL-18 were investigated by immunofluorescence staining, dual luciferase reporter gene assay, RT-qPCR assay ChIP assay, and RIP assay followed by the analysis of their effects on RA in vivo and in vitro after expression alteration. The expressions of NEAT1, p-p65, p300, and IL-18 were all upregulated in the synovial tissues from the mice and patients with RA. NEAT1 silencing reduced the infiltration of CD4⁺ T cells and macrophages in synovial tissues, downregulated expression of blood inflammatory factors, relieved RA severity, and lowered incidence of RA in mice. Further, p-p65 could increase the expression of NEAT1 by binding to the NEAT1 promoter region, NEAT1 could co-locate and interact with p300, thus regulating the expression of IL-18 by regulating histone acetylation modification in IL-18 promoter region. NEAT1 aggravated RA via p300/CBP/IL-18 axis, representing a promising therapeutic target in RA.

Prospective evaluation of 5 urinary biomarkers as predictors of acute kidney injury in nonazotemic, hospitalized dogs

BACKGROUND

Early recognition of acute kidney injury (AKI) is hindered by current definitions and use of traditional, insensitive markers.

HYPOTHESIS/OBJECTIVES

Urinary (u) activity of γ-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP), and concentrations of heat-shock protein 70 (HSP70) and interleukins (ILs) -6 and -18, are predictive biomarkers for AKI and survival.

ANIMALS

Nonazotemic, hospitalized dogs (n = 118) and healthy controls (n = 20).

METHODS

A prospective observational study. Nonazotemic dogs at risk of AKI were recruited and their urinary biomarker concentrations were measured at presentation. Serum creatinine (sCr) and symmetric dimethylarginine (sSDMA) were measured daily until discharge/death.

RESULTS

The overall case fatality rate was 18.6%. Fifteen dogs (12.7%) developed AKI, which was associated with death (relative risk, 3.2; 95% confidence interval [CI], 1.57-6.55). All 5 urinary biomarkers were significantly higher in hospitalized dogs compared to controls, with minimal overlap. uHSP70/uCr, uGGT/uCr, and uIL-6/uCr at presentation were higher in dogs which later developed AKI. Areas under the receiver operator characteristic curve (AUROC) (95% CI) for the 3 biomarkers as predictors of AKI were 0.67 (0.51-0.83), 0.68 (0.55-0.81), and 0.78 (0.65-0.91), respectively. When they were categorically classified as elevated/normal, each additional elevated biomarker increased the odds for AKI (OR, 2.83; 95% CI, 1.23-6.52, P = .01). Agreement between sCr and sSDMA was poor (Cohen's kappa = .071). The AUROC of SDMA at presentation for AKI prediction was 0.73 (0.51-0.95).

CONCLUSIONS AND CLINICAL IMPORTANCE

Kidney injury was common, irrespective of subsequent worsening of azotemia or death. The predictive value of individual urinary biomarkers was reduced by moderate sensitivities and specificities. SDMA showed moderate discriminatory utility for AKI prediction, and often displayed discordant results with sCr.

A dysregulated interleukin-18-interferon-γ-CXCL9 axis impacts treatment response to canakinumab in systemic juvenile idiopathic arthritis

OBJECTIVES

The monoclonal IL-1β antibody canakinumab is approved for the treatment of systemic juvenile idiopathic arthritis (SJIA). Its efficacy has been proven in several trials, but not all patients show a complete and sustained response to therapy. We aimed to analyse the association of baseline serum biomarkers with treatment outcome in patients with SJIA treated with canakinumab.

METHODS

Serum samples from 54 patients with active SJIA without recent macrophage activation syndrome (MAS) treated with canakinumab in an open-label response characterization study were subjected to a multiplexed bead array assay. Interesting targets from these analyses were validated by ELISA. Clinical treatment outcomes included modified paediatric ACR (pACR) 30 and 90 responses, clinically inactive disease (CID) within 15 days of treatment and sustained complete response, defined as pACR100 or CID within 15 days of treatment plus no future flare or MAS.

RESULTS

In canakinumab-naïve patients most biomarkers were elevated when compared with healthy controls at baseline and some rapidly decreased by day 15 [IL-1 receptor antagonist (IL-1RA), IL-6, IL-18 and S100A12]. Responders had higher IL-18 and IFN-γ levels and lower chemokine (C-X-C motif) ligand 9 (CXCL9) levels at baseline, emphasized by the IL-18: CXCL9 and IFN-γ: CXCL9 ratios. These ratios had significant accuracy in predicting treatment responses.

CONCLUSION

Differential regulation of the IL-18-IFN-γ-CXCL9 axis is observed in patients with SJIA. Higher IL-18: CXCL9 and IFN-γ: CXCL9 ratios at baseline are associated with a better clinical response to canakinumab treatment in SJIA. Future studies are needed to validate these findings and determine their generalizability to patients with recent MAS.

IL-18 (Interleukin-18) Produced by Renal Tubular Epithelial Cells Promotes Renal Inflammation and Injury During Deoxycorticosterone/Salt-Induced Hypertension in Mice

IL-18 (interleukin-18) is elevated in hypertensive patients, but its contribution to high blood pressure and end-organ damage is unknown. We examined the role of IL-18 in the development of renal inflammation and injury in a mouse model of low-renin hypertension. Hypertension was induced in male C57BL6/J (WT) and IL-18−/− mice by uninephrectomy, deoxycorticosterone acetate (2.4 mg/d, s.c.) and 0.9% drinking saline (1K/DOCA/salt). Normotensive controls received uninephrectomy and placebo (1K/placebo). Blood pressure was measured via tail cuff or radiotelemetry. After 21 days, kidneys were harvested for (immuno)histochemical, quantitative-PCR and flow cytometric analyses of fibrosis, inflammation, and immune cell infiltration. 1K/DOCA/salt-treated WT mice developed hypertension, renal fibrosis, upregulation of proinflammatory genes, and accumulation of CD3+ T cells in the kidneys. They also displayed increased expression of IL-18 on tubular epithelial cells. IL-18−/− mice were profoundly protected from hypertension, renal fibrosis, and inflammation. Bone marrow transplantation between WT and IL-18−/− mice revealed that IL-18-deficiency in non-bone marrow-derived cells alone afforded equivalent protection against hypertension and renal injury as global IL-18 deficiency. IL-18 receptor subunits—interleukin-18 receptor 1 and IL-18R accessory protein—were upregulated in kidneys of 1K/DOCA/salt-treated WT mice and localized to T cells and tubular epithelial cells. T cells from kidneys of 1K/DOCA/salt-treated mice produced interferon-γ upon ex vivo stimulation with IL-18, whereas those from 1K/placebo mice did not. In conclusion, IL-18 production by tubular epithelial cells contributes to elevated blood pressure, renal inflammation, and fibrosis in 1K/DOCA/salt-treated mice, highlighting it as a promising therapeutic target for hypertension and kidney disease.

Usefulness of Interleukin-18 as a Diagnostic Biomarker to Differentiate Adult-Onset Still's Disease With/Without Macrophage Activation Syndrome From Other Secondary Hemophagocytic Lymphohistiocytosis in Adults

Background

Interleukin (IL)-18 is markedly elevated in systemic inflammatory diseases that cause the ‘cytokine storm’ such as adult-onset Still’s disease (AOSD) and hemophagocytic lymphohistiocytosis (HLH). The differences in IL-18 between AOSD and HLH, especially in adults, is uncertain. Macrophage activation syndrome (MAS), a form of secondary HLH, is often difficult to differentiate cases of AOSD that include MAS from other secondary HLH. In this case-control study, we investigated whether serum IL-18 levels could be a useful biomarker for the differential diagnosis of AOSD with or without MAS (AOSD group) and other secondary HLH in adults (adult HLH group).

Patients and Methods

We enrolled 46 patients diagnosed with AOSD including 9 patients with MAS and 31 patients in the adult HLH group, which excluded AOSD-associated MAS. The clinical features and laboratory data were compared between the AOSD and adult HLH groups. In addition, we subdivided the AOSD group (with or without MAS) and the adult HLH group (whether lymphoma-associated or not) and compared the four groups. A logistic regression analysis was used to identify factors with high efficacy in differentiating the two groups, followed by a receiver operating characteristic (ROC) curve analysis to evaluate the differential diagnostic ability of IL-18. We analyzed the correlation between IL-18 and various laboratory parameters in the AOSD group.

Results

Serum IL-18 levels of patients in the AOSD groups were significantly higher than those of the adult HLH groups, and were closely correlated with ferritin, soluble interleukin-2 receptor (sIL-2R), and other laboratory data. Univariate and multivariate logistic regression analyses revealed that IL-18, sIL-2R, and ‘arthralgia or arthritis’ are independent factors useful in the differential diagnosis of AOSD from adult HLH. In the differential diagnosis of both groups, the area under the curve obtained from the ROC curve of IL-18 with a cutoff value of 18,550 pg/mL was 0.91 (95% confidence interval 0.83–1.00; sensitivity 90.3%, specificity 93.5%), and the differential diagnosis ability of IL-18 was superior to that of other laboratory data.

Conclusions

IL-18 could be a useful biomarker for the differential diagnosis of AOSD and adult HLH.

First Description of Late-Onset Autoinflammatory Disease Due to Somatic NLRC4 Mosaicism

INTRODUCTION

Autoinflammatory diseases (AIDs) are inherited disorders of innate immunity that usually start during childhood. However, several studies have recently reported an increasing number of patients with AID starting in adulthood.

OBJECTIVE

This study was undertaken to characterize the cause underlying a patient with late-onset uncharacterized AID.

METHODS

Genetic studies were performed using Sanger sequencing and next-generation sequencing (NGS) methods. In silico, in vitro and ex vivo analyses were performed to determine the functional consequences of the detected variant.

RESULTS

We studied a 57 years-old woman who started at the age of 47 years with recurrent episodes of fever, myalgias, arthralgias, diffuse abdominal pain, diarrhea, adenopathies and systemic inflammation, which were relatively well controlled with anti-IL-1 drugs. NGS analyses did not detect germline variants in any of the known AID-associated genes, but they identified the p.Ser171Phe NLRC4 variant in unfractionated blood, with an allele fraction (2-4%) compatible with gene mosaicism. Structural modeling analyses suggest that this missense variant might favor the open, active conformation of the NLRC4 protein, and in vitro and ex vivo analyses confirmed its trend to oligomerize and activate the NLRC4-inflammasome, with a subsequent IL-18 overproduction.

CONCLUSION

We have identified the post-zygotic p.Ser171Phe NLRC4 variant as a plausible cause of the disease in the enrolled patient. Functional and structural studies clearly support for the first time its gain-of-function behavior consistent with previously reported NLRC4 pathogenic variants. These novel evidences should be considered in the diagnostic workup of patients with uncharacterized AID starting during adulthood.

Genetic and commensal induction of IL-18 drive intestinal epithelial MHCII via IFNγ

Major histocompatibility complex class II (MHCII) is dynamically expressed on intestinal epithelial cells (IECs) throughout the intestine, but its regulation remains poorly understood. We observed that spontaneous upregulation of IEC MHCII in locally bred Rag1^-/- mice correlated with serum Interleukin (IL)-18, was transferrable via co-housing to commercially bred immunodeficient mice and could be inhibited by both IL-12 and IL-18 blockade. Overproduction of intestinal IL-18 due to an activating Nlrc4 mutation upregulated IEC MHCII via classical inflammasome machinery independently of immunodeficiency or dysbiosis. Immunodeficient dysbiosis increased Il-18 transcription, which synergized with NLRC4 inflammasome activity to drive elevations in serum IL-18. This IL-18-MHCII axis was confirmed in several other models of intestinal and systemic inflammation. Elevated IL-18 reliably preceded MHCII upregulation, suggesting an indirect effect on IECs, and mice with IL-18 overproduction showed activation or expansion of type 1 lymphocytes. Interferon gamma (IFNg) was uniquely able to upregulate IEC MHCII in enteroid cultures and was required for MHCII upregulation in several in vivo systems. Thus, we have linked intestinal dysbiosis, systemic inflammation, and inflammasome activity to IEC MHCII upregulation via an intestinal IL-18-IFNg axis. Understanding this process may be crucial for determining the contribution of IEC MHCII to intestinal homeostasis, host defense, and tolerance.

The Comparison of Predictive Value Among Chemerin, IL-18 and Hormonal Parameters in Assessing the Risk of Metabolic Syndrome in Men

Chemerin (CHEM) is a new proinflammatory adipokine involved in the immune, metabolic and reproductive processes. Low-grade state inflammation (LGSI) is a key element in the pathogenesis of metabolic syndrome (MS). Low SHBG is a good marker of male hypogonadism in MS. This study evaluated the prognostic value of selected adipokine, LGSI, and androgenic parameters in predicting the risk of MS among men. One hundred thirty-two random men aged 40 to 70 years old were enrolled. Measurements of anthropometric indices, blood pressure, and laboratory tests were carried out. A total of 62 men (47%) were diagnosed with MS. Chemerin concentrations were higher in men diagnosed with MS compared to healthy: 89.48 (78.12-112.10) vs. 77.9 (65.12-98.64) ng/mL; p = .002. Men diagnosed with MS presented with lower levels of total testosterone: 5.75 (4.00-6.57) vs. 6.40 (5.50-8.40) ng/mL; p = .0014 and SHBG: 46.58 (35.13-66.28) vs. 71.97 (56.1-92.7) nM/L; p < 0.000001. Elevated LGSI indices were demonstrated in men with MS as opposed to healthy [IL-18: 530.64 (409.12-640.56) vs. 418.85 (348.14-496.44) pg/mL; p = .000033 and hs-CRP: 2.15 (0.97-4.26) vs. 1.01 (0.41-2.68) ng/mL; p = .0057)]. In multivariate regression analysis, the highest negative predictive value in assessing the risk of MS was SHBG serum concentration, while the highest positive predictive values were: IL-18, hypertriglyceridemia, and waist circumference. Decreased SHBG levels, combined with elevated IL-18 concentrations in men showing hypertriglyceridemic waist phenotype, significantly increase the risk of MS.

The Controversy About the Effects of Different Doses of Corticosteroid Treatment on Clinical Outcomes for Acute Respiratory Distress Syndrome Patients: An Observational Study

Background: Corticosteroid usage in acute respiratory distress syndrome (ARDS) remains controversial. We aim to explore the correlation between the different doses of corticosteroid administration and the prognosis of ARDS.

Methods: All patients were diagnosed with ARDS on initial hospital admission and received systemic corticosteroid treatment for ARDS. The main outcomes were the effects of corticosteroid treatment on clinical parameters and the mortality of ARDS patients. Secondary outcomes were factors associated with the mortality of ARDS patients.

Results: 105 ARDS patients were included in this study. Corticosteroid treatment markedly decreased serum interleukin-18 (IL-18) level (424.0 ± 32.19 vs. 290.2 ± 17.14; p = 0.0003) and improved arterial partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FiO₂) (174.10 ± 65.28 vs. 255.42 ± 92.49; p < 0.0001). The acute physiology and chronic health evaluation (APACHE II) score (16.15 ± 4.41 vs. 14.88 ± 4.57, p = 0.042) decreased significantly on the seventh day after systemic corticosteroid treatment. Interestingly, the serum IL-18 decreased significantly (304.52 ± 286.00 vs. 85.85 ± 97.22, p < 0.0001), whereas the improvement of PaO₂/FiO₂ (24.78 ± 35.03 vs. 97.17 ± 44.82, p < 0.001) was inconspicuous after systemic corticosteroid treatment for non-survival patients, compared with survival patients. Furthermore, the receiver operating characteristic (ROC) model revealed, when equivalent methylprednisolone usage was 146.5 mg/d, it had the best sensitivity and specificity to predict the death of ARDS. Survival analysis by Kaplan–Meier curves presented the higher 45-day mortality in high-dose corticosteroid treatment group (logrank test p < 0.0001). Multivariate Cox regression analyses demonstrated that serum IL-18 level, APACHE II score, D-dimer, and high-dose corticosteroid treatment were associated with the death of ARDS.

Conclusion: Appropriate dose of corticosteroids may be beneficial for ARDS patients through improving the oxygenation and moderately inhibiting inflammatory response. The benefits and risks should be carefully weighed when using high-dose corticosteroid for ARDS.

Trial registration: This work was registered in ClinicalTrials.gov. Name of the registry: Corticosteroid Treatment for Acute Respiratory Distress Syndrome. Trial registration number: NCT02819453. URL of trial registry record: https://register.clinicaltrials.gov.

Longitudinal Changes of Cytokines and Appetite in Older Hospitalized Patients

There are few data on the longitudinal association of cytokine and appetite among older hospitalized patients. We aimed to investigate the impact of the changes of inflammatory cytokines on appetite in older hospitalized patients. A total of 191 patients (mean age 81.3 ± 6.6 years, 64% women) participated in this prospective longitudinal observational study. Appetite was evaluated using the Edmonton Symptom Assessment System on admission and after seven days. Serum cytokines such as IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-17, IL-18, IL-23 and IL-33, IFN-α2, IFN-γ, TNF-α and MCP-1 were measured both times. No significant differences in the mean serum levels of all the cytokines could be detected overtime in relation to appetite changes, except for IL-18. Appetite significantly deteriorated overtime in patients with increasing IL-18 levels and improved in those without significant changes in IL-18 levels. In a stepwise regression analysis, changes of IL-18 levels were the major independent predictor for the changes of patients' appetite and explained 4% of the variance, whereas other cytokines and variables, such as age, sex, infection and disease, did not show any impact on appetite changes. We conclude that IL-18 seems to exert a significant impact on appetite in acutely ill older hospitalized patients and should, therefore, be considered as a potential target in the diagnosis, prevention and treatment of malnutrition.

The implication of interferon-γ-producing immunocompetent cells for evaluating disease activity and severity in adult-onset Still's disease

OBJECTIVE

To investigate the relationship between interferon-γ (IFN-γ), IFN-γ-producing immunocompetent cells, their related cytokines, and the clinical features in adult-onset Still's disease (AOSD).

METHODS

Twenty-five patients with AOSD before initiating treatment (acute AOSD), 9 patients after remission (remission AOSD), and 12 healthy controls (HC) were included. Circulating IFN-γ-producing CD4+ and CD8+ cells, natural killer (NK) cells, and IFN-γ production in NK cells were evaluated by flow cytometry. Serum levels of IFN-γ, interleukin (IL)-6, IL-12, IL-15, and IL-18 were also measured. The obtained results were statistically analyzed with clinical findings.

RESULTS

Serum levels of IFN-γ, IL-6, IL-12, IL-18, intracellular expression of IFN-γ in CD4+, CD8+, and NK cells were significantly higher in acute AOSD than in HC. The proportion of NK cells was significantly lower in acute AOSD than in HC. Serum levels of IFN-γ and IFN-γ expression in CD4+ cells were significantly correlated with serum ferritin levels. The proportion of NK cells had a significant inverse correlation with serum IFN-γ levels. A lower proportion of NK cells was significantly noted in patients refractory to initial immunosuppressive treatment. In remission AOSD, serum levels of IL-6, IL-12, and IL-18 were significantly higher than in HC.

CONCLUSION

Increased serum levels of IFN-γ, increased expression of IFN-γ in CD4+ cells, and decreased NK cell proportion correlate with disease activity in AOSD. Moreover, a lower proportion of NK cells may be useful for predicting a refractory clinical course. Meanwhile, increased serum levels of IL-6, IL-12, and IL-18 may persist after clinical remission.

Effect of betulinic acid administration on TLR-9/NF-κB /IL-18 levels in experimental liver injury

Background/aim

Acetaminophen (APAP), used in the composition of thousands of preparations, is the most commonly used analgesic and antipyretic drug. The present study aimed to investigate the potential protective effects of the betulinic acid (BA) treatment through an APAP-induced hepatotoxicity rat model, using inflammatory, biochemical, and histopathological parameters.

Materials and methods

The study consisted of four groups: control group, APAP group, BA group, and APAP+BA group. Experimental studies continued for fifteen days. Serum samples were analysed for glucose, total cholesterol (TChol), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), aspartate amino transferase (AST), malondialdehyde (MDA), toll-like receptor-9 (TLR-9), nuclear factor kappa B (NF-κB), and interleukin-18 (IL-18).

Results

TLR9, IL-18, NF-κB, and MDA levels increased significantly in liver injury groups. These increases considerably decreased by the BA treatment. All groups showed immunopositivity for 8-hydroxy-2’–deoxyguanosine (8-OHdG) and interleukin (IL-1β) in the hepatocytes, inflammatory cells, and epithelial cells of bile ducts.

Conclusion

BA can be used as an effective agent in the prevention and treatment of acute liver diseases due to its inhibitory properties in multiple pathways and its potent antioxidant effects.

Src-IL-18 signaling regulates the secretion of atrial natriuretic factor in hypoxic beating rat atria

BACKGROUND

Interleukin (IL)-18 is produced mainly in the heart, and can be associated to the development of cardiac hypertrophy that leads to cardiac dysfunction. However, the effects of hypoxia on IL-18 expression and atrial natriuretic factor (ANF) secretion remain largely unknown.

AIM

To assess the effect of hypoxia on IL-18 production and its role in ANF secretion by using an isolated perfused beating rat atrial model.

METHODS

The level of ANF in the perfusates was determined by radioimmunoassay, and the protein levels of Src, IL-18 and its receptors (IL-18-Rα and IL-18-Rβ), Rho guanine nucleotide exchange factor (RhoGEF) and RhoA, activating transcription factor 3 (ATF3), T cell factor (TCF) 3 and 4, and lymphoid enhancer factor (LEF) 1 in atrial tissue samples were detected by Western blotting.

RESULTS

Hypoxia significantly upregulated the expression of non-receptor tyrosine kinase Src, and this effect was blocked by endothelin-1 receptor type A (BQ123) and type B (BQ788) antagonists. Hypoxia also enhanced the expression of RhoGEF and RhoA concomitantly with the upregulation of IL-18, IL-18-Rα and IL-18-Rβ. The hypoxia-induced RhoGEF and RhoA were abolished by Src inhibitor 1 (SrcI), and the protein levels of IL-18 and its two receptors were also blocked by SrcI. Moreover, the hypoxia-induced expression levels of ATF3, TCF3, TCF4 and LEF1 were repealed by IL-18 binding protein, and the hypoxia-promoted secretion of ANF was also obviously attenuated by this binding protein.

CONCLUSIONS

These findings imply that Src-IL-18 signaling is involved in the release of ANF in hypoxic beating rat atria.

Clinical significance of interleukin-18 for the diagnosis and prediction of disease course in systemic juvenile idiopathic arthritis

OBJECTIVE

To investigate the clinical significance of serum IL-18 levels for the diagnosis of systemic JIA (s-JIA) and to predict the disease course of s-JIA.

METHODS

Overall, 116 patients with s-JIA, 151 with other diseases and 20 healthy controls were analysed. Serum IL-18 levels were measured longitudinally in 41 patients with s-JIA from active phase through remission phase. Serum IL-18 levels were quantified via enzyme-linked immunosorbent assay and the results were compared with clinical features and the disease course of s-JIA.

RESULTS

The serum IL-18 level cut-off value for differentiation of s-JIA from other diseases was 4800 pg/ml. In patients with a monocyclic course, serum IL-18 levels steadily decreased during the inactive phase and low levels were sustained during remission. In contrast, in patients with a chronic course, elevated serum IL-18 levels were sustained even during the inactive phase. In patients with a polycyclic course, serum IL-18 levels were elevated during disease flares and normalized during the inactive phase. The serum IL-18 level cut-off value for diagnosis of remission in s-JIA was 595 pg/ml.

CONCLUSION

Serum IL-18 levels of >4800 pg/ml may be useful for differentiating between s-JIA and other diseases. Monitoring of serum IL-18 levels might be useful for predicting the disease course and assessing remission in s-JIA.

NLR value and IL-18 level and their clinical significance in patients with deep vein thrombosis after receiving the surgery for spinal degeneration

OBJECTIVE

To investigate the value of the neutrophil-to-lymphocyte ratio (NLR) and Interleukin 18 (IL-18) level in patients with deep vein thrombosis after receiving surgery for spinal degeneration; and we explore their significance in clinical practice.

METHODS

This study was conducted in 296 patients who were treated in our hospital for spinal degeneration. After surgery, these patients were followed up for 1 month. After performing the color Doppler ultrasound examination, patients were divided into the thrombus group (n = 72) and the non-thrombus group (n = 224) based on the occurrence of deep vein thrombosis. Baseline data, NLR values and IL-18 levels before surgery, and at 1, 3, 5, and 7 days after surgery were compared between the two groups. Logistic regression analysis was implemented to analyze the risk factors for postoperative deep vein thrombosis. Patients in the thrombosis group were allocated to the mild, moderate, and severe group on the basis of the degree of thrombosis. NLR values and IL-18 levels at 3 days after surgery were compared among the three groups. The correlations between both NLR value and IL-18 level and the severity of deep vein thrombosis were analyzed with Pearson correlation. Receiver operating characteristic curve was used to assess the clinical value of NLR value and IL-18 level at 3 days after surgery in predicting postoperative deep vein thrombosis.

RESULTS

There were significant differences concerning age, the history of diabetes, and obesity between the two groups (all P<0.05). NLR values and IL-18 levels in both groups after surgery were increased when compared with before surgery (all P<0.01). In addition, NLR values and IL-18 levels reached a peak at 3 days after surgery. Compared with the non-thrombus group, NLR values and IL-18 levels in the thrombus group at 1, 3, 5, and 7 days after surgery were increased (all P<0.01). NLR value and IL-18 level in the thrombosis group at 3 days after surgery were increased with a worsened degree of thrombosis. In other words, both NLR value and IL-18 level were positively correlated with the degree of deep vein thrombosis. The results of logistic regression analysis displayed that age ≥60 years old, body mass index ≥23 kg/m², NLR value >4.34%, and IL-18 level >115.71 ng/mL were independent risk factors for postoperative deep vein thrombosis. The results of the ROC curve showed that the area under curves, which represent the formation of postoperative deep vein thrombosis, were above 0.7 when using NLR value and IL-18 level at 3 days after surgery (both P<0.001).

CONCLUSION

Compared with the non-thrombus group, NLR value and IL-18 level in the thrombosis group after receiving surgery for spinal degeneration are significantly increased. In addition, the more severe the thrombosis is, the higher the NLR value and IL-18 level at 3 days after surgery. Therefore, NLR value and IL-18 level at 3 days after surgery have certain clinical value in predicting postoperative deep vein thrombosis and prognosis.

Predicting Acute Respiratory Distress Syndrome in Severe Blunt Trauma: The Utility of Interleukin-18

Background: In trauma, direct pulmonary injury and innate immune response activation primes the lungs for acute respiratory distress syndrome (ARDS). The inflammasome-dependent release of interleukin-18 (IL-18) was recently identified as a key mediator in ARDS pathogenesis, leading us to hypothesize that plasma IL-18 is a diagnostic predictor of ARDS in severe blunt trauma. Patients and Methods: Secondary analysis of the Inflammation and Host Response to Injury database was performed on plasma cytokines collected within 12 hours of severe blunt trauma. Trauma-related cytokines, including IL-18, were compared between patients with and without ARDS and were evaluated for association with ARDS using regression analysis. Threshold cytokine concentrations predictive of ARDS were determined using receiver-operating curve (ROC) analysis. Results: Cytokine analysis of patients without ARDS patients (n = 61) compared with patients with ARDS (n = 19) demonstrated elevated plasma IL-18 concentration in ARDS and IL-18 remained correlated with ARDS on logistic regression after confounder adjustment (p = 0.008). Additionally, ROC analysis revealed IL-18 as a strong ARDS predictor (area under the curve [AUC] = 0.83), with a threshold IL-18 value of 170 pg/mL (Youden index, 0.3). Unlike in patients without ARDS, elevated IL-18 persisted in patients with ARDS during the acute injury phase (p ≤ 0.02). Other trauma-related cytokines did not correlate with ARDS. Conclusions: In severe blunt trauma, IL-18 is a robust predictor of ARDS and remains elevated throughout the acute injury phase. These findings support the use of IL-18 as a key ARDS biomarker, promoting early identification of trauma patients at greater risk of developing ARDS. Timely recognition of ARDS and implementation of advantageous supportive care practices may reduce trauma-related ARDS morbidity and costs.

Macrophage activation syndrome in systemic juvenile idiopathic arthritis

Macrophage activation syndrome (MAS) is a severe, potentially life-threatening complication of systemic juvenile idiopathic arthritis (s-JIA). An immunological feature is the excessive activation and proliferation of T lymphocytes and macrophages. Massive hypercytokinemia is strongly associated with its pathogenesis, particularly the overproduction of interleukin (IL)-1, IL-6 and IL-18; interferon (IFN)-γ; and tumor necrosis factor (TNF)-α. Furthermore, heterozygous mutations in causative genes for primary hemophagocytic lymphohistiocytosis and in vivo exposure to highly elevated levels of IL-6 and IL-18 might induce natural killer cell dysfunction and decrease their numbers, respectively. A proper diagnosis is important to begin appropriate therapeutic interventions and change an unfavorable prognosis. The 2016 ACR/EULAR classification criteria for MAS have a high diagnostic performance; however, the diagnostic sensitivity for onset is relatively low. Therefore, careful monitoring of laboratory values during the course of MAS is necessary to diagnose it early in s-JIA. Further studies on the diagnosis and monitoring of disease activity using serum cytokine profile and a targeted cytokine strategy are required.

Pro-Inflammatory Interleukin-18 is Associated with Hepatic Steatosis and Elevated Liver Enzymes in People with HIV Monoinfection

People with HIV (PWH) are at an increased risk of developing nonalcoholic fatty liver disease (NAFLD). Interleukin (IL)-18 is regulated by inflammasomes in response to pathogens and danger signals and has been implicated in both the pathogenesis of NAFLD and HIV disease progression. We hypothesized that increased IL-18 may be associated with NAFLD and liver injury in PWH. This was an observational study of 125 PWH and 59 individuals without HIV in the Boston area. Participants with known hepatitis B, hepatitis C, and excessive alcohol use were excluded. IL-18 was measured in serum by enzyme-linked immunosorbent assay. Liver lipid content was assessed by liver-to-spleen computed tomography (CT) attenuation ratio. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and IL-18 levels were higher in PWH than in controls. In PWH, log₁₀ IL-18 was associated with log₁₀AST (r = 0.34, p = .0001), log₁₀ALT (r = 0.33, p = .0002), log₁₀HIV RNA (r = 0.29, p = .002), and inversely associated with liver-to-spleen ratio (r = -0.24, p = .02). In addition, log₁₀ IL-18 was associated with log₁₀ triglycerides (r = 0.26, p = .003), log₁₀ MCP-1 (monocyte chemoattractant protein-1; r = 0.33, p = .0004), log₁₀caspase-1 (r = 0.35, p < .0001), log₁₀LPS (r = 0.28, p = .004), and inversely associated with high-density lipoprotein (r = -0.28, p = .002), and CD4⁺/CD8⁺ T cell ratio (r = -0.24, p = .007). In controls without HIV, log₁₀ IL-18 was also associated with log₁₀ALT (r = 0.44, p = .0005). After adjusting for potential confounders, the relationships between IL-18 and AST (p = .004) and ALT (p = .003) remained significant, and the relationship between IL-18 and liver-to-spleen ratio (p = .02). Increased inflammasome activation and subsequent monocyte recruitment in PWH may contribute to the development and progression of NAFLD. Clinical Trials Registration. NCT00455793.

Correlation between the levels of NLRP3, Hcy, IL-1β, IL-18 and the prognosis in patients with hemorrhagic stroke

OBJECTIVE

To explore the connection of nucleotide-binding oligomerization domain-like receptors 3 (NLRP3), homocysteine (Hcy), interleukin-1β (IL-1β), interleukin-18 (IL-18) in peripheral blood and prognosis in patients with hemorrhagic stroke.

METHODS

A total of 84 patients with hemorrhagic stroke treated in our hospital were selected and divided into the good prognosis group (48 cases) and the poor prognosis group (36 cases) according to the Glasgow Prognostic Scale (GOS) at month 6 after discharge. 40 people who were matched for age, sex and risk factors for cerebral hemorrhage, but did not have cerebral hemorrhage, were selected as a control group. We detected the levels of NLRP3, Hcy, IL-1β and IL-18 in peripheral blood, and analyzed their correlation with GOS score. Then we performed Logistic regression analysis to investigate the risk factors for poor prognosis.

RESULTS

The expressions of NLRP3 mRNA, Hcy, IL-1β and IL-18 in peripheral blood in the poor prognosis group were higher than those in the good prognosis group (P<0.05). The expression levels of NLRP3 mRNA, Hcy, IL-1β and IL-18 were negatively correlated with GOS scores (P<0.05). Regression analysis showed that the expression of NLRP3 mRNA, serum Hcy, bleeding volume and ventricular system penetration were independent risk factors for poor prognosis.

CONCLUSION

In patients with poor prognosis of hemorrhagic stroke, the mRNA levels of NLRP3 and serum Hcy, IL-1β and IL-18 levels in peripheral blood elevated. High NLRP3 mRNA levels, Hcy levels, bleeding volume and ventricle system penetration are independent risk factors for poor prognosis.

COVID-19 and HIV-Associated Immune Reconstitution Inflammatory Syndrome: Emergence of Pathogen-Specific Immune Responses Adding Fuel to the Fire

Both coronavirus disease 2019 (COVID-19) and mycobacterial immune reconstitution inflammatory syndrome (IRIS) in patients with HIV-1 infection result from immunopathology that is characterized by increased production of multiple pro-inflammatory chemokines and cytokines associated with activation of myeloid cells (monocytes, macrophages and neutrophils). We propose that both conditions arise because innate immune responses generated in the absence of effective adaptive immune responses lead to monocyte/macrophage activation that is amplified by the emergence of a pathogen-specific adaptive immune response skewed towards monocyte/macrophage activating activity by the immunomodulatory effects of cytokines produced during the innate response, particularly interleukin-18. In mycobacterial IRIS, that disease-enhancing immune response is dominated by a Th1 CD4⁺ T cell response against mycobacterial antigens. By analogy, it is proposed that in severe COVID-19, amplification of monocyte/macrophage activation results from the effects of a SARS-CoV-2 spike protein antibody response with pro-inflammatory characteristics, including high proportions of IgG3 and IgA2 antibodies and afucosylation of IgG1 antibodies, that arises from B cell differentiation in an extra-follicular pathway promoted by activation of mucosa-associated invariant T cells. We suggest that therapy for the hyperinflammation underlying both COVID-19 and mycobacterial IRIS might be improved by targeting the immunomodulatory as well as the pro-inflammatory effects of the ‘cytokine storm’.

Significance of expression of AIM2, IL1β, and IL18 in plasma of patients with acute cerebral infarction

OBJECTIVES

Inflammation especially the overexpression of inflammasome and inflammatory cytokines, is one of the important reasons that affect the occurrence and development of acute cerebral infarction, including the initiation of cerebral infarction, the progress and recovery of post-infarction injury. This study aims to explore expressions of absent in melanoma 2 (AIM2), interleukin-1β (IL-1β), and interleukin-18 (IL-18) in plasma of patients with acute cerebral infarction and its significance.

METHODS

A total of 85 patients with acute cerebral infarction were enrolled in the cerebral infarction group. They were assigned into mild, moderate, and severe groups according to the severity of neurological deficits. They were assigned into small, middle, and large cerebral infarction groups according to the area of cerebral infarction. They were assigned into a good prognosis group and a poor prognosis group according to the Modified Rankin Scale (mRS) score on the 90th day after the onset. A total of 85 healthy controls were selected as a control group. The levels of AIM2, IL-1β, and IL-18 in plasma of the cerebral group and the control group were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The levels of plasma AIM2, IL-1β, and IL-18 in the cerebral infarction group were significantly higher than those in the control group (all P<0.001). In the cerebral infarction group, the expression levels of plasma AIM2, IL-1β, and IL-18 were as follows: The severe neurological deficitc group>the moderate group>the mild group, the large area of cerebral infarction group>the middle area group>the small area group, and the poor prognosis group> the good prognosis group (all P<0.05). The levels of plasma AIM2 were positively correlated with National Institute of Health Stroke Scale (NIHSS) score, the cerebral infarction area, and the mRS score (r=0.791, r=0.710, r=0.763, respectively, all P<0.001). The levels of plasma IL-1β were positively correlated with the NIHSS score, the cerebral infarction area, and the mRS score (r=0.716, r=0.690, r=0.688, respectively, all P<0.001). The levels of plasma IL-18 were positively correlated with the NIHSS score, the cerebral infarction area, and the mRS score (r=0.714, r=0.638, r=0.653, respectively, all P<0.001). The level of plasma AIM2 was positively correlated with that of IL-1β and IL-18 (r=0.828, r=0.751, both P<0.001).

CONCLUSIONS

Expressions of AIM2, IL-1β, and IL-18 are up-regulated in the plasma of patients with acute cerebral infarction, and they are closely related to the severity of neurological deficit, cerebral infarction area, and prognosis in patients with acute cerebral infarction, suggesting that AIM2, IL-1β, and IL-18 may play an important role in the occurrence and development of acute cerebral infarction.