Clinical Value of Serum Interleukin-18 in Neonatal Sepsis Diagnosis and Mortality Prediction

Purpose

Previous studies have demonstrated that interleukin-18 (IL-18) levels were elevated in adult patients with sepsis. However, its role in neonatal sepsis remains unknown. The current research was conducted to assess the clinical value of serum IL-18 level as a candidate biomarker in neonatal sepsis diagnosis and prediction of mortality.

Patients and Methods

From July 2022 to September 2022, we prospectively enrolled 91 septic neonates and 31 non-sepsis neonates in the intensive care unit of neonates at Henan Children's Hospital in Zhengzhou, China. Neonatal peripheral blood serum was collected at admission and levels of serum IL-18 were assessed. Employing multivariate logistic regression analysis, the evaluation of the potential of IL-18 as an independent biomarker for sepsis was executed. Furthermore, employing the receiver operating characteristic (ROC) curve analysis, the diagnostic value of IL-18 in sepsis and the ability of IL-18 in predicting the mortality of neonatal sepsis was measured. The statistical package SPSS 24.0 was employed to conduct all statistical analyses.

Results

Serum IL-18 levels in neonates in the sepsis group were elevated compared to the control group, reaching the highest levels in the non-survival sepsis group (P < 0.001). Correlation analysis exhibited a positive relationship between IL-18 levels and age, body temperature, respiratory rate, and C-reactive protein levels. IL-18 was identified as an independent biomarker in identifying sepsis (OR = 4.747, 95% CI 1.493-15.092, P = 0.008) by multiple logistic regression. ROC curve analysis exhibited that IL-18 was good in identifying neonatal sepsis (area under curve (AUC) = 0.77, 95% CI = 0.68-0.85, P < 0.001) and predicting neonatal mortality (AUC = 0.80, 95% CI = 0.63-0.96, P = 0.003).

Conclusion

IL-18 was a potential biomarker for identifying neonatal sepsis and neonatal mortality prediction.

Refractory adult-onset Still's disease complicated with monoclonal gammopathy of undetermined significance: A case report

RATIONALE

Adult-onset Still's disease (AOSD) is a rare inflammatory disease characterized by a classic triad of daily spike fever, arthritis, and a typical salmon-pink rash. The involvement of inflammatory cytokines by various factors such as infection, drug, or neoplasm causes refractory AOSD.

PATIENT CONCERNS

We report a 63-year-old man with a high fever, rash, hyperferritinemia, and M proteinemia. His serum levels of interleukin-6 and interleukin-18 were remarkably high at 192 and 114,250 pg/mL, respectively.

DIAGNOSIS

AOSD complicated with monoclonal gammopathy of undetermined significance was diagnosed.

INTERVENTIONS

After steroid pulse therapy followed by oral prednisolone, cyclosporin, methotrexate, and colchicine, serum ferritin levels temporarily declined, but secondary cytomegalovirus infections exacerbated AOSD's activity.

OUTCOMES

Finally, after tocilizumab induction, AOSD activity was gradually suppressed over a long period.

LESSONS

The disease activity of AOSD is exacerbated by multiple factors, including comorbidities or infections. Clinicians need to consider that monoclonal gammopathy of undetermined significance complications might become AOSD refractory by an elevation of the inflammatory cytokines. Moreover, further prospective studies are required to confirm this result.

Modifying Effect of the Interleukin-18 Level on the Association between BDNF Methylation and Long-Term Cardiovascular Outcomes in Patients with Acute Coronary Syndrome

This study investigated the potential modifying effects of the level of the serum interleukin-18 (IL-18) on the association between BDNF methylation status and long-term cardiovascular outcomes in patients with acute coronary syndrome (ACS). Hospitalized ACS patients were recruited sequentially from 2006 to 2012. At baseline, the IL-18 level and BDNF methylation status were evaluated in 969 patients who were followed for major adverse cardiac events (MACEs) for 5-12 years, until 2017 or death. The time to first composite or individual MACE was compared between individuals with lower and higher average BDNF methylation levels (in the low- and high-IL-18 groups, respectively) using a Cox proportional hazards model. After adjusting for potential covariates, the modifying effects of IL-18 and average BDNF methylation levels on the initial composite and individual MACEs were examined. In the high-IL-18 group, but not in the low-IL-18 group, a higher average BDNF methylation level was associated with increases in composite MACEs (HR (95% CI) = 2.15 (1.42-3.26)), all-cause mortality (HR (95% CI) = 1.89 (1.11-3.22)), myocardial infarction (HR (95% CI) = 1.98 (1.07-3.67)), and percutaneous coronary intervention (HR (95% CI) = 1.81 (1.01-3.23)), independent of confounding variables. The interaction effect between the IL-18 and average BDNF methylation levels on composite MACEs (p = 0.019) and myocardial infarction (p = 0.027) was significant after adjusting for covariates. Analysis of BDNF methylation status and IL-18 levels may help identify ACS patients who are most likely to have adverse clinical outcomes.

Altered Expression of Interleukin-18 System mRNA at the Level of Endometrial Myometrial Interface in Women with Adenomyosis

Adenomyosis is a uterine pathology characterized by a deep invasion of endometrial glands and stroma, disrupting the endometrial−myometrial interface (EMI). Interleukin-18 (IL-18) system is a dominant cytokine involved in the menstrual cycle of human endometrium. IL-18 may play a defensive role against maternal immune response in the uterine cavity. The present study was designed to determine IL-18-mediated immune response at the level of EMI. We uncovered that mRNA of IL-18 system, including IL-18, IL-18 receptor (IL-18R), and its antagonist, IL-18 binding protein (IL-18BP), expressed in eutopic, ectopic endometrium, and corresponding myometrium in patients with adenomyosis. IL-18 system was demonstrated in paired tissue samples by immunochemistry and immunofluorescence study. According to RT-PCR with CT value quantification and 2−∆∆Ct method, a significant down-regulation of IL-18BP in corresponding myometrium in comparison to eutopic endometrium (p < 0.05) indicates that the IL-18 system acts as a local immune modulator at the level of EMI and regulating cytokine networks in the pathogenesis of adenomyosis. Furthermore, an increased IL-18 antagonist to agonist ratio was noted in ectopic endometrium compared with corresponding myometrium. We suggest that altered IL-18 system expression contributes to immunological dysfunction and junctional zone disturbance in women with adenomyosis.

Fulminant elderly adult-onset Still disease effectively treated with tocilizumab and methotrexate: A case report

RATIONALE

Adult-onset Still disease (AOSD) is a rare inflammatory disease of unknown etiology. AOSD is common in young or middle-aged adults; however, in recent years, there have been increasing reports of elderly AOSD. Differentiating AOSD from diseases such as infections and malignancies is difficult. Moreover, rare fulminant AOSD cases with resistance to corticosteroids and immunosuppressive drugs have been reported.

PATIENT CONCERNS

An 80-year-old woman presented with flaccid fever, generalized arthralgia, and erythema of the anterior chest for 2 weeks. On day 5 of hospitalization, the patient developed pleural effusion with hypoxemia and her vital signs indicated rapid progression to shock. During the clinical course, the levels of inflammatory markers, including maximum level of ferritin and white blood cells (WBCs) were elevated (252,796 ng/mL and 86,500/μV, respectively) with disseminated intravascular coagulation syndrome (DIC) and macrophage activation syndrome (MAS).

DIAGNOSIS

The patient was diagnosed with elderly AOSD as per the Yamaguchi criteria for AOSD. The state of disease was extremely severe with rapid progression and was, thus, categorized as a fulminant form of elderly AOSD.

INTERVENTIONS

The patient was treated with prednisolone (PSL) pulse therapy (1000 mg/d) twice and plasma exchange in the intensive care unit for the primary disease and shock. Although she recovered from shock, she developed DIC and MAS. Methotrexate (MTX; 10 mg/d) improved the DIC and MAS. However, severe pleuritis recurred and the patient developed pericarditis; her primary disease was poorly controlled. Finally, tocilizumab (TCZ) was introduced using interleukin-18 (IL-18) as a surrogate marker. The IL-18 level was measured repeatedly following admission, with the peak level (170,000 pg/mL) recorded on the 75th day of hospitalization, immediately prior to introducing TCZ.

OUTCOMES

The combined use of MTX, TCZ, and PSL was effective in suppressing elderly AOSD, which was unsuccessfully controlled with MTX and PSL. Frequent monitoring of IL-18 levels proved useful for differentiating elderly AOSD from other diseases.

LESSONS

A fulminant form of elderly AOSD was treated with a combination of MTX, TCZ, and PSL. Repeated monitoring of IL-18 levels can be useful for decision-making in treating elderly AOSD.

Significant Contribution of Interleukin-18 Genotypes to Lung Cancer Risk in Taiwanese

BACKGROUND/AIM

The elevated expression of interleukin-18 (IL-18) among lung cancer patients raised our curiosity to examine the role of IL-18 genotypes in lung cancer.

MATERIALS AND METHODS

IL-18 -656 (rs1946519), -607 (rs1946518), and -137 (rs187238) genotypes of 358 lung cancer cases and 716 controls were determined via the PCR-RFLP methodology.

RESULTS

The distributions of genotypic and allelic frequencies of IL-18 -607, but not those of -656 or -137, were differentially distributed between cases and controls. IL-18 -607 AC and CC genotypes were both lower (45.8% and 16.2%) in lung cancer patients compared to controls (51.4% and 24.7%). In addition, IL-18 -607 AC and CC genotypes were of significantly lower percentages both among non-smokers and smokers. Otherwise, no differential distribution was found regarding IL-18 -656 or -137.

CONCLUSION

IL-18 -607 C allele can serve as a protective predictor for lung cancer risk in Taiwanese.

Impact of PCSK9 Inhibition on Proinflammatory Cytokines and Matrix Metalloproteinases Release in Patients with Mixed Hyperlipidemia and Vulnerable Atherosclerotic Plaque

Atherosclerosis is a disorder in which, in addition to high cholesterol levels, several plasma factors play a significant role in its development. Among these cytokines and molecules are interleukin 6 (IL-6), interleukin 18 (IL-18), tumor necrosis factor α (TNF-α), metalloproteinase 2 (MMP-2), and metalloproteinase 9 (MMP-9), all of which may contribute to the stabilization of atherosclerotic plaque. The purpose of this study was to determine the effect of advanced lipid-lowering therapy on the levels of these determinants by utilizing proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors in patients with verified high-risk atherosclerotic plaque. Methods: The study involved patients with dyslipidemia who had the presence of unstable atherosclerotic plaque verified by ultrasonography and who were eligible to begin alirocumab treatment. The levels of IL-6, IL, 18, TNF-α, and MMPs were determined in this group before and after three months of therapy. After treatment, a statistically significant decrease in concentrations of Il-18, Il-6, TNF-α (p < 0.001) and MMP-2 (p < 0.05) was observed. Additionally, we observed that the concentrations of these markers were significantly higher in the group of patients prior to initiating therapy than in the control group. Our study’s results suggest that PCSK-9 inhibitor therapy significantly reduces the concentration of factors influencing the stability of atherosclerotic plaque, which may explain their essential importance in reducing cardiovascular risk in patients receiving this treatment.

Baseline clinical features predicting macrophage activation syndrome in patients with systemic adult-onset Still's disease receiving interleukin-6 inhibitor treatment

AIM

Macrophage activation syndrome (MAS), a severe complication of systemic adult-onset Still's disease (AOSD), has been reported to occur during interleukin-6 (IL-6) inhibitor treatment. However, predictors for MAS development are unknown. Therefore, this study investigated predictive features for MAS development after starting IL-6 inhibitor treatment in systemic AOSD patients.

METHOD

In a single-center retrospective study involving systemic AOSD patients who were refractory to high-dose glucocorticoids with immunosuppressants and started IL-6 inhibitor treatment between April 2008 and March 2020, we compared the baseline clinical features between patients who developed AOSD flare with MAS features (MAS group) and those who did not (non-MAS group) during IL-6 inhibitor treatment.

RESULTS

Only tocilizumab was used as an IL-6 inhibitor. Six of 14 refractory systemic AOSD patients developed AOSD flares with MAS features during tocilizumab treatment, including 4 who developed them shortly after initiation. The MAS group had significantly lower neutrophil counts, fibrinogen, and higher IL-18/C-reactive protein (CRP) ratio at starting tocilizumab (baseline) than the non-MAS group. Before starting tocilizumab, neutrophil counts were trending downward and upward in the MAS and non-MAS groups, respectively, with significant differences in changes. Receiver operating characteristic analysis showed that baseline neutrophil counts and fibrinogen and their changes before tocilizumab treatment and baseline IL-18/CRP ratio had significant discriminatory abilities for subsequent MAS development.

CONCLUSION

We identified baseline laboratory features associated with MAS development after initiating an IL-6 inhibitor in refractory systemic AOSD patients. These features may reflect the suppression of IL-6 signaling, and further suppression of IL-6 signaling might trigger early-onset MAS.

Liposomal β-Sitosterol Suppresses Metastasis of CT26/luc Colon Carcinoma via Inhibition of MMP-9 and Evoke of Immune System

β-sitosterol (SITO) has been reported with anticancer effects; however, with poor bioavailability. The current study aimed to investigate whether liposomal encapsulated β-sitosterol (LS) has a better inhibition effect on tumor metastasis than β-sitosterol in a CT26/luc lung metastasis mouse model and the possible underlying mechanism. LS was liposomal-encapsulated SITO and was delivered to mice by oral gavage. The cell viability was determined by the MTT assay, and invasiveness of the tumor cells and related protein expression were evaluated with the invasion assay and Western blotting. For therapeutic efficacy evaluation, male BALB/c mice were treated with PBS, SITO, and LS once a day for 7 days prior to intravenous injections of CT26/luc cells; treatments were continued twice a week post-cell inoculation throughout the entire experiment. Tumor growth inhibition was monitored by bioluminescent imaging (BLI). IL-12, IL-18, and IFN-γ in the intestinal epithelium were determined by ELISA. The results show that LS treatment had a better invasion inhibition with lower cytotoxicity than SITO when the same dose was utilized. Notably, mice treated with LS significantly exhibited fewer metastases to the lungs and other tissues/organs compared with the Control and SITO groups. Additionally, the IL-12, IL-18, and IFN-γ levels were significantly increased in the LS-treated mice compared with the Control and SITO groups. The underlying mechanism may be through the inhibition of MMP-9 and elicitation of the antitumoral Th1 immune response, such as increasing CD4⁺ and CD8⁺ T cells, IL-12, IL-18, and IFN-γ.

Associations between single-nucleotide polymorphisms of the interleukin-18 gene and breast cancer in Iraqi women

According to long-term projections, by 2030, the world’s population is predicted to reach 7.5 billion individuals, and there will be roughly 27 million new cancer cases diagnosed. The global burden of breast cancer (BC) is expected to rise. According to the Ministry of Health-Iraqi Cancer Registry, cancer is the second largest cause of death after cardiovascular disease. This study investigated the interleukin-18 (IL18) single-nucleotide polymorphisms (SNPs) –607C/A rs1946518 and –137G/C rs187238 using the sequence-specific amplification-polymerase chain reaction approach. Regarding the position –607C/A, there was a highly significant difference between the observed and expected frequencies in patients and controls (χ² = 3.16 and χ² = 16.5), respectively. The AA and CA genotypes were associated with significantly increased BC risk (odds ratio [OR], 3.68; p = 0.004 and OR, 2.83; p = 0.04, respectively). Women with the A allele had a 5.03-fold increased susceptibility to BC. The C allele may be a protective allele against BC (OR, 0.19). Although position –137G/C showed no significant differences in the CC genotype distribution (p = 0.18), the frequency of the CC genotype was significantly higher in patients than in controls. In contrast, patients had a significantly higher frequency of GC genotypes than controls (p = 0.04), which was associated with an increased risk of developing BC (OR, 2.63). The G allele frequency was significantly lower in patients than in controls (55.0% vs. 76.2%, respectively). This SNP may be considered a common genotype in the Iraqi population, with the wild-type G allele having a protective function (OR, 0.19) and the mutant C allele having an environmental effect (OR, 2.63).

Serotonin receptor subtype-2B signaling is associated with interleukin-18-induced cardiomyoblast hypertrophy in vitro

Background

In patients with heart failure, interleukin-18 (IL-18) levels increase in the circulatory system and injured myocardial tissue. Serotonin (5-hydroxytryptamine) receptors subtype 2B (HTR2B) play an essential role in cardiac function and development, and their overexpression in rats leads to myocardial hypertrophy. Epigallocatechin gallate (EGCG) is cardioprotective in myocardial ischemia-reperfusion injury in rats and can prevent pressure overload-mediated cardiac hypertrophy in vivo. Mice deficient in peroxisome proliferator-activated receptor delta (PPARδ) can have cardiac dysfunction, myocardial hypertrophy, and heart failure. Matrix metalloproteinases (MMPs) are possibly involved in cardiac remodeling. However, the relationship between IL-18 signaling, cardiac hypertrophy, and the molecular mechanisms involved remain to be fully elucidated.

Objectives

To elucidate the relationship between HTR2B and IL-18-induced myocardial hypertrophy and examine the antihypertrophic effects of EGCG and PPARδ.

Methods

We induced H9c2 cardiomyoblast hypertrophy with IL-18 in vitro and investigated the downstream signaling by real-time polymerase chain reaction (PCR) and western blotting. Hypertrophy was assessed by flow cytometry. We determined the effects of EGCG and PPARδ on IL-18-induced hypertrophic signaling via HTR2B-dependent mechanisms.

Results

IL-18-induced H9c2 hypertrophy upregulated brain natriuretic peptide (BNP) protein and mRNA expression by inducing the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and the hypertrophy was attenuated by pretreatment with EGCG (20 μM) and L-165,041 (2 μM), a PPARδ agonist. IL-18 upregulated the expression of HTR2B, which was inhibited by pretreatment with EGCG and L-165,041. SB215505 (0.1 μM), a HTR2B antagonist and siRNA for HTR2B, attenuated H9c2 hypertrophy significantly. Inhibition of HTR2B also downregulated the expression of MMP-3 and MMP-9.

Conclusions

IL-18 and HTR2B play critical roles in cardiomyoblast hypertrophy. EGCG and L-165,041 inhibit the expression of HTR2B and augment remodeling of H9c2 cardiomyoblasts, possibly mediated by MMP-3 and MMP-9.

Interleukin-18 mediated inflammatory brain injury after intracerebral hemorrhage in male mice

Interleukin-18 (IL-18), a pro-inflammatory cytokine, is thought to be associated with inflammation in many neurological diseases such as ischemic stroke and poststroke depression, but the role of IL-18 in inflammatory injury after intracerebral hemorrhage (ICH) remains unclear. In this study, we established the ICH model in male mice and found that IL-18 expression including protein and mRNA levels was significantly increased in brain tissues after ICH. Meanwhile, exogenous IL-18 exacerbated cerebral hematoma and neurological deficits following ICH. In the IL-18 knockout group, the size of hematoma and neurological functions after ICH was decreased compared with the wild-type group, suggesting the critical role of IL-18 on the modulation of brain injury after ICH. Importantly, exogenous IL-18 increased microglial activation in brain tissues after ICH. Furthermore, IL-18 knockout resulted in the reduction of activated microglia after ICH. These results indicated that IL-18 may regulate the inflammatory response after ICH through the activation of microglia. Thus, IL-18 is expected to be a promising therapeutic target for secondary brain injury after ICH.

Elevated levels of interleukin-18 are associated with several indices of general and visceral adiposity and insulin resistance in women with polycystic ovary syndrome

Objective

Our aim was to analyze levels of proinflammatory biomarker interleukin-18 (IL-18) in healthy controls and patients with polycystic ovary syndrome (PCOS) focusing on its association with obesity, clinical, hormonal, and metabolic characteristics.

Methods

Fifty-eight patients with PCOS were enrolled in the study fulfilling the Rotterdam criteria and were matched for age, body mass index (BMI), and ethnicity with 30 healthy controls. Detailed anthropometric measurements, clinical investigations, hormonal and biochemical tests were obtained between the 3^rd and 5^th day of a menstrual cycle. A subanalysis of the PCOS group was performed separating patients into several groups according to a waist-to-height ratio (WHtR), insulin resistance (IR), and free androgen index (FAI). Serum IL-18 levels were measured using the ELISA method.

Results

Levels of IL-18 were similar between PCOS patients and controls. IL-18 was higher in overweight/obese women compared to normal-weight women when analyzing all participants together and separately PCOS or controls group (p < 0.001, p < 0.001, p = 0.01, respectively). Additionally, IL-18 levels were higher in high-WHtR and IR subgroups compared to low-WHtR (p < 0.001) and non-IR PCOS women (p < 0.001). PCOS women with high FAI had greater serum IL-18 levels than normal-FAI patients (p = 0.002). Levels of IL-18 correlated positively with most of the anthropometric and metabolic parameters. In multiple linear regression, age, waist circumference, and fasting insulin were independently related factors with IL-18.

Conclusion

Elevated levels of IL-18 were related to several indices of general and visceral adiposity and insulin resistance in PCOS.

Systemic Juvenile Idiopathic Arthritis/Pediatric Still's Disease, a Syndrome but Several Clinical Forms: Recent Therapeutic Approaches

BACKGROUND

Systemic Juvenile Idiopathic Arthritis (SJIA)/Pediatric Still's disease is associated with different phenotypes and outcomes from currently available treatments.

METHODS

A review of opinion, based on personal experience in a reference pediatric rheumatology center and key publications, to explore the most important questions regarding disease heterogeneity and treatment approaches.

RESULTS

A few situations deserve particular attention: 1/patients with recent-onset SJIA who may benefit from a treat-to-target approach with a key place for interleukin (IL)-1 inhibition; 2/SJIA patients refractory to Il-1 and IL-6 antagonists in whom several options may be discussed, including thalidomide or allogeneic hematopoietic stem cell transplantation; 3/SJIA patients with macrophage activation syndrome who may benefit from both well-used classical treatment and innovative approaches, such as anti-interferon gamma therapy or Janus Kinase (JAK) inhibitors; 4/SJIA with severe lung involvement, 5/SJIA patients who achieve complete remission on treatment, with some recent evidence that treatment may be reduced in intensity but not so easily withdrawn.

CONCLUSIONS

a case-by-case discussion with expert teams is recommended in this heterogeneous, often difficult-to-treat population of patients.

Proinflammatory Cytokines (IL-1, -6, -8, -15, -17, -18, -23, TNF-α) Single Nucleotide Polymorphisms in Rheumatoid Arthritis-A Literature Review

Conducted studies highlight that a mixture of genetic and environmental factors is responsible for rheumatoid arthritis (RA) development. This study aimed to analyze the available literature for the relationship between, on the one hand, single-nucleotide polymorphisms (SNPs) in the proinflammatory cytokines genes interleukin-1 (IL-1), -6, -8, -15, -17, -18, and -23, and tumor necrosis factor-alpha (TNF-α), and on the other hand, RA susceptibility, severity, and patients' response to applied treatment. The PubMed database was searched for sources. Preference was given to articles which were published within the past 20 years. Data indicate that the relationship between selected SNPs in proinflammatory cytokines genes and susceptibility to developing RA is inconclusive, and it depends on the ethnicity of the population. Although the allelic and genotypic frequencies of many SNPs in proinflammatory cytokines genes analyzed did not differ between RA patients and healthy controls, deeper analysis showed that these polymorphisms have a relationship with clinicopathological features of RA. SNPs in proinflammatory cytokines genes also "modify patients' response" to applied treatment. Further studies, on larger cohorts of subjects and in different populations, should be conducted to elucidate the role of SNPs in IL-1, -6, -8, -15, -17, -18, and -23, and TNF-α genes in RA patients.

Urine Biomarkers for the Assessment of Acute Kidney Injury in Neonates with Hypoxic Ischemic Encephalopathy Receiving Therapeutic Hypothermia

OBJECTIVE

To evaluate the predictive performance of urine biomarkers for acute kidney injury (AKI) in neonates with hypoxic ischemic encephalopathy (HIE) receiving therapeutic hypothermia.

STUDY DESIGN

We performed a multicenter prospective observational study of 64 neonates. Urine specimens were obtained at 12, 24, 48, and 72 hours of life and evaluated for neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), cystatin C, interleukin-18 (IL-18), tissue inhibitor of metalloproteinases 2 (TIMP2), and insulin-like growth factor-binding protein 7 (IGFBP7). Logistic regression models with receiver operating characteristics for area under the curve (AUC) were used to assess associations with neonatal modified KDIGO (Kidney Disease: Improving Global Outcomes) AKI criteria.

RESULTS

AKI occurred in 16 of 64 infants (25%). Neonates with AKI had more days of vasopressor drug use compared with those without AKI (median [IQR], 2 [0-5] days vs 0 [0-2] days; P = .026). Mortality was greater in neonates with AKI (25% vs 2%; P = .012). Although NGAL, KIM-1, and IL-18 were significantly associated with AKI, the AUCs yielded only a fair prediction. KIM-1 had the best predictive performance across time points, with an AUC (SE) of 0.79 (0.11) at 48 hours of life. NGAL and IL-18 had AUCs (SE) of 0.78 (0.09) and 0.73 (0.10), respectively, at 48 hours of life.

CONCLUSIONS

Urine NGAL, KIM-1, and IL-18 levels were elevated in neonates with HIE receiving therapeutic hypothermia who developed AKI. However, wide variability and unclear cutoff levels make their clinical utility unclear.

SARS-CoV-2 S Protein Subunit 1 Elicits Ca2+ Influx - Dependent Ca2+ Signals in Pancreatic Stellate Cells and Macrophages In Situ

The S protein subunit 1 (S1) of SARS-CoV-2 is known to be responsible for the binding of the virus to host cell receptors, but the initial intracellular signalling steps following receptor activation of cells in the exocrine pancreas are unknown. Using an intact live mouse pancreatic lobule preparation, we observed that S1 elicited Ca²⁺ signals in stellate cells and macrophages, but not in the dominant acinar cells. The Ca²⁺ signals occurred mostly in the form of repetitive Ca²⁺ spikes. The probability of observing Ca²⁺ signals depended on the S1 concentration. The threshold was close to 70 nM, whereas at 600 nM, all cells responded. The SARS-Cov-2 nucleocapsid protein did not elicit any Ca²⁺ signals in any of the three cell types tested. The S1-induced Ca²⁺ signals in stellate cells started much faster (122 ± 37s) than those in macrophages (468 ± 68s). Furthermore, the interleukin-18 binding protein (IL-18BP) abolished the responses in macrophages without affecting the Ca²⁺ signals in stellate cells. The S1-elicited Ca²⁺ signals were completely dependent on the presence of external Ca²⁺ and were abolished by a selective inhibitor (CM4620) of Orai1 Ca²⁺ Release Activated Ca²⁺ channels. SARS-CoV-2 may contribute to acute pancreatitis, an often fatal inflammatory human disease. The S1-elicited Ca²⁺ signals we have observed in the pancreatic stellate cells and endogenous macrophages may play an important part in the development of the inflammatory process.

Mucosal-associated invariant T cells are activated in an interleukin-18-dependent manner in Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases

Mucosal-associated invariant T (MAIT) cells are a type of innate immune cells that protect against some infections. However, the involvement of MAIT cells in Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases (EBV-T/NK-LPD) is unclear. In this study, we found that MAIT cells were highly activated in the blood of patients with EBV-T/NK-LPD. MAIT cell activation levels correlated with disease severity and plasma IL-18 levels. Stimulation of healthy peripheral blood mononuclear cells with EBV resulted in activation of MAIT cells, and this activation level was enhanced by exogenous IL-18. MAIT cells stimulated by IL-18 might thus be involved in the immunopathogenesis of EBV-T/NK-LPD.

Circulating LIGHT (TNFSF14) and Interleukin-18 Levels in Sepsis-Induced Multi-Organ Injuries

The novel therapeutic target cytokine LIGHT (TNFSF14) was recently shown to play a major role in COVID-19-induced acute respiratory distress syndrome (ARDS). This study aims to investigate the associations of plasma LIGHT and another potentially targetable cytokine, interleukin-18 (IL-18), with ARDS, acute hypoxic respiratory failure (AHRF), or acute kidney injury (AKI), caused by non-COVID-19 viral or bacterial sepsis. A total of 280 subjects diagnosed with sepsis, including 91 cases with sepsis triggered by viral infections, were investigated in this cohort study. Day 0 plasma LIGHT and IL-18, as well as 59 other biomarkers (cytokines, chemokines, and acute-phase reactants) were measured by sensitive bead immunoassay and associated with symptom severity. We observed significantly increased LIGHT level in both bacterial sepsis patients (p = 1.80 × 10⁻⁵) and patients with sepsis from viral infections (p = 1.78 × 10⁻³). In bacterial sepsis, increased LIGHT level was associated with ARDS, AKI, and higher Apache III scores, findings also supported by correlations of LIGHT with other biomarkers of organ failure. IL-18 levels were highly variable across individuals and consistently correlated with Apache III scores, mortality, and AKI in both bacterial and viral sepsis. There was no correlation between LIGHT and IL-18. For the first time, we demonstrate independent effects of LIGHT and IL-18 in septic organ failure. The association of plasma LIGHT with AHRF suggests that targeting the pathway warrants exploration, and ongoing trials may soon elucidate whether this is beneficial. Given the large variance of plasma IL-18 among septic subjects, targeting this pathway requires precise application.

Macrophage activation syndrome in patients with adult-onset Still's disease under tocilizumab treatment: A single-center observational study

OBJECTIVES

Macrophage activation syndrome (MAS) developed under tocilizumab treatment poses a diagnostic challenge. This study aims to demonstrate the frequency and the clinical features of MAS developed in patients with adult-onset Still's disease (AOSD) receiving tocilizumab.

METHODS

The consecutive AOSD patients treated with tocilizumab in our institution from April 2008 to March 2020 were studied. The frequency of clinically diagnosed MAS during tocilizumab treatment, their conformity to the several criteria relevant for MAS, and laboratory characteristics compared to AOSD flare were investigated.

RESULTS

Of the 20 AOSD patients treated with tocilizumab, six developed clinically diagnosed MAS, four immediately after starting tocilizumab and two after long-term treatment. Some of them had already met the MAS criteria before starting tocilizumab. At MAS diagnosis, although some did not meet the MAS criteria due to lack of fever and/or the lower ferritin levels, all consistently showed sharp increases in ferritin along with marked abnormal changes in two or more different markers of organ damage, unlike the AOSD flares.

CONCLUSION

MAS is not a rare complication in AOSD patients receiving tocilizumab. The clinical similarities between systemic AOSD and MAS, and substantial alterations in MAS features by inhibition of interleukin-6 signaling may limit the utility of the existing diagnostic/classification criteria in diagnosing MAS under tocilizumab treatment. The emergence of abnormalities in MAS-related organ damage markers with a rapid elevation of ferritin should be considered as MAS development in AOSD patients receiving tocilizumab even if the patients are afebrile or have relatively low ferritin levels.

Interleukin-18 in metabolism: From mice physiology to human diseases

Interleukin-18 (IL-18) is a classical member of the IL-1 superfamily of cytokines. As IL-1β, IL-18 precursor is processed by inflammasome/caspase-1 into a mature and biologically active form. IL-18 binds to its specific receptor composed of two chains (IL-18Rα and IL-18Rβ) to trigger a similar intracellular signaling pathway as IL-1, ultimately leading to activation of NF-κB and inflammatory processes. Independently of this IL-1-like signaling, IL-18 also specifically induces IFN-γ production, driving the Th1 immune response. In circulation, IL-18 binds to the IL-18 binding protein (IL-18BP) with high affinity, letting only a small fraction of free IL-18 able to trigger receptor-mediated signaling. In contrast to other IL-1 family members, IL-18 is produced constitutively by different cell types, suggesting implications in normal physiology. If the roles of IL-18 in inflammatory processes and infectious diseases are well described, recent experimental studies in mice have highlighted the action of IL-18 signaling in the control of energy homeostasis, pancreatic islet immunity and liver integrity during nutritional stress. At the same time, clinical observations implicate IL-18 in various metabolic diseases including obesity, type 1 and 2 diabetes and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). In the present review, we summarize and discuss both the physiological actions of IL-18 in metabolism and its potential roles in pathophysiological mechanisms leading to the most common human metabolic disorders, such as obesity, diabetes and NAFLD/NASH.

Association of IL-8 -251T&gt;A and IL-18 -607C&gt;A polymorphisms with susceptibility to breast cancer - a meta-analysis

BACKGROUND

Previous studies have evaluated the association of IL-8 -251T&gt;A and IL-18 -607C&gt;A polymorphisms with a risk of breast cancer in different populations, but the results remain inconsistent and inconclusive. Thus, we performed this meta-analysis to explore the associations.

METHODS

A comprehensive literature search in PubMed, EMBASE, Web of Science, Scopus, SciELO, SID, and CNKI for all eligible studies published up to October 1, 2020. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the intensity of associations.

RESULTS

A total of 12 case-control studies including seven studies with 2,370 cases and 2,314 controls on IL-8 -251T&gt;A, and five studies with 900 cases and 882 con-trols on IL-18 -607C&gt;A polymorphism were selected. Pooled data showed that IL-8 -251T&gt;A (AT vs. TT: OR= 1.187; 95% CI 1.038-1.356; P = 0.012) and IL-18 -607C&gt;A polymorphisms (A vs. T: OR = 1.205; 95% CI 1.055-1.377; P = 0.006; AA vs. TT: OR = 1.379; 95% CI 1.056-1.802; P = 018; and AA vs. AT+TT: OR = 1.329; 95% CI 1.053-1.678; P = 0.017) were associated with increased risk of breast cancer in overall. Moreover, when the studies were stratified by ethnicity, the IL-8 -251T&gt;A was significantly associated with breast cancer risk in Africans. Publication bias tests provide no evidence of presence of publication bias in a meta-analysis.

CONCLUSION

This meta-analysis results revealed that the IL-8 -251T&gt;A and IL-18 -607C&gt;A polymorphisms are associated with susceptibility to breast cancer. However, further multicenter studies with larger sample sizes in different ethnicities are required to make a better assessment of these associations.

Serum and synovial fluid concentrations of interleukin-18 and interleukin-20 in patients with osteoarthritis of the knee and their correlation with other markers of inflammation and turnover of joint cartilage

INTRODUCTION

Osteoarthritis (OA) is the most common degenerative joint disease, and its aetiology is not entirely known. The aim of the study was to evaluate the involvement of interleukin-18 (IL-18) and interleukin-20 (IL-20) in the pathogenesis of knee OA and their correlations with other markers of inflammation and destruction of joint cartilage, as well as clinical and radiological changes.

MATERIAL AND METHODS

The study included 25 patients with knee OA and a control group. The concentration of IL-18, IL-20, IL-6, MMP-1, MMP-3, COMP, PG-AG, and YKL-40 in serum and synovial fluid (SF) were determined. We also evaluated radiological lesions of the knee joint according to the Kellgren-Lawrence (K-L) scale, and clinical severity of the disease according to Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne Index.

RESULTS

The concentrations of IL-18 and IL-20 were statistically significantly higher in serum of patients with OA than in the control group (106.00 ±189.76 pg/ml vs. 16.73 ±16.99 pg/ml, p < 0.001, 17.69 ±13.45 pg/ml vs. 9.76 ±9.00 pg/ml, p < 0.014). Serum concentration of IL-18 positively correlated with MMP-3 (R = 0.58; p = 0.006) and YKL-40 (R = 0.48; p = 0.002). The degree of radiological advancement of OA (K-L scale) correlated positively with clinical evaluation (WOMAC, R = 0.74, p ≤ 0.001; Lequesne Index, R = 0.57, p = 0.003).

CONCLUSIONS

The analysis of ROC curves showed that IL-20 as well as COMP, MMP-3, and YKL-40 may be diagnostic markers of knee OA. The observations indicate that IL-18 potentially mediates mainly in intra-articular processes and IL-20 could be primarily responsible for the systemic inflammatory reaction.

Role of E148Q in familial Mediterranean fever with an exon 10 mutation in MEFV

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive disease caused by mutations in the MEFV gene. Mutations in exon 10 are associated with typical FMF. Most Japanese patients with typical FMF are compound heterozygotes of M694I in exon 10 and E148Q in exon 2. However, the pathogenic role of E148Q remains controversial.

METHODS

We assessed symptoms and serum cytokines among patients with FMF and their family members. They were divided into three subgroups, based on MEFV mutations: individuals carrying M694I and E148Q (group A, n = 14), individuals carrying M694I, but not E148Q (group B, n = 10), and individuals carrying E148Q, but not M694I (group C, n = 11).

RESULTS

All but one individual in group A had typical FMF phenotypes, whereas no individual in groups B and C exhibited any episodes of fever or serositis. The serum levels of interleukin-18 during the afebrile phase were significantly elevated in group A (2,806 ± 2,107 pg/mL), compared to those in groups B (499 ± 369 pg/mL) and C (427 ± 410 pg/mL). No difference in interleukin-6 levels was observed among the three groups.

CONCLUSIONS

These findings indicated that E148Q may contribute to disease development of FMF in Japanese patients carrying the heterozygous M694I mutation in MEFV and that genetic testing of both parents would lead to better counseling for their children.