Association between IL-18/18R gene polymorphisms and coronary artery disease: influence of IL-18/18R genetic variants on cytokine expression

Relationships between Interleukin 18 -607 C/A and -137 G/C, Osteopontin -9250 C/T Genetic Polymorphisms and Systemic Inflammatory Response Syndrome in Coronary Artery Bypass Graft Surgery

Background and Objectives: Systemic inflammatory response syndrome (SIRS) is one of the most significant complications after on-pump heart surgery procedures. High cytokine levels have been shown after open-heart surgeries and a genetic predisposition seems to be an important underlying modulatory characteristic for SIRS. To investigate the association between interleukin 18 -607 C/A, interleukin 18 -137 G/C and osteopontin 9250 C/T genetic polymorphisms and SIRS in on-pump CABG patients. Materials and Methods: Two hundred consecutive elective on-pump CABG patients were recruited prospectively to the study. Genomic DNA was extracted from whole blood and genotyping was determined by sequence specific PCR or PCR-RFLP methods for related polymorphisms. Results: SIRS incidence was 60.2%, 38.1%, 18.9% on postoperative day 1, 2 and 3, respectively, in the whole study population. The SIRS rate on the second postoperative day was 13% and 43.4%, respectively, in osteopontin 9250 C/T T allele non-carriers and carriers (p = 0.004). WBC (White Blood Cell) counts were higher on day 2 and 3 in osteopontin 9250 C/T T allele carriers compared to non-carriers (day 2; 12.7 ± 4 vs. 10.5 ± 2.4 (p = 0.015), day 3; 11.8 ± 4 vs. 9.1 ± 4.7 (p = 0.035)). The average ICU stay was 3.1 ± 7.4, 1.28 ± 0.97 for IL 18-137 G/C C allele carriers and non-carriers, respectively (p = 0.003), and in the IL 18-137 G/C C allele carriers, SIRS developed in 42.2% by the second postoperative day whereas the rate was 57.8% in non-carriers (p = 0.025). Conclusions: The current research revealed a possible link between osteopontin 9250 C/T and IL18-137 G/C genetic polymorphism and SIRS and morbidity in on-pump CABG patients.

The Potential of Single Nucleotide Polymorphisms (SNPs) as Biomarkers and Their Association with the Increased Risk of Coronary Heart Disease: A Systematic Review

Human genetic analyses and epidemiological studies showed a potential association between several types of gene polymorphism and the development of coronary heart disease (CHD). Many studies on this pertinent topic need to be investigated further to reach an evidence-based conclusion. Therefore, in this current review, we describe several types of gene polymorphisms that are potentially linked to CHD. A systematic review using the databases EBSCO, PubMed, and ScienceDirect databases was searched until October of 2022 to find relevant studies on the topic of gene polymorphisms on risk factors for CHD, especially for the factors associated with single nucleotide polymorphisms (SNPs). The risk of bias and quality assessment was evaluated by Joanna Briggs Institute (JBI) guidelines. From keyword search results, a total of 6243 articles were identified, which were subsequently narrowed to 14 articles using prespecified inclusion criteria. The results suggested that there were 33 single nucleotide polymorphisms (SNPs) that can potentially increase the risk factors and clinical symptoms of CHD. This study also indicated that gene polymorphisms had a potential role in increasing CHD risk factors that were causally associated with atherosclerosis, increased homocysteine, immune/inflammatory response, Low-Density Lipoprotein (LDL), arterial lesions, and reduction of therapeutic effectiveness. In conclusion, the findings of this study indicate that SNPs may increase risk factors for CHD and SNPs show different effects between individuals. This demonstrates that knowledge of SNPs on CHD risk factors can be used to develop biomarkers for diagnostics and therapeutic response prediction to decide successful therapy and become the basis for defining personalized medicine in future.

Association between polymorphisms in interleukin-18 promoter and risk of coronary artery disease: a meta-analysis

Background: Previous studies have explored associations between interleukin-18 (IL-18) promoter polymorphisms and coronary artery disease (CAD). However, the results were controversial. We conducted a meta-analysis to clarify the association between the two polymorphisms and CAD risk. Methods: We searched English and Chinese databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to estimate whether there are genetic associations between IL-18 promoter polymorphisms and the risk of CAD. All relevant studies were screened and meta-analyzed using STATA 15.0. Results: A total of 15 studies, including 12 studies for -137 G/C and 9 studies for -607 C/A, were identified for the meta-analysis. For -137 G/C, the results showed a significantly reduced risk of CAD in the dominant model (OR = 0.85) and heterozygous model (OR = 0.88) in the overall analysis. However, in subgroup analysis, decreased CAD risks were only observed in Asian populations for heterozygous genetic models. For -607 C/A, the overall OR revealed a reduced risk of CAD in all five genetic models (allelic, OR = 0.78; recessive, OR = 0.75; dominant, OR = 0.68; homozygous, OR = 0.61; heterozygous, OR = 0.72). In subgroup analysis, reduced CAD risk was also found in five genetic models of the Asian population. We also found that the IL-18 polymorphisms were correlated with myocardial infarction (MI) and multivessel (MV) disease. Conclusion: Our results suggested that the -137 polymorphism and -607 polymorphism in the IL-18 promoter were negatively associated with CAD, especially in the Asian population. In addition, some genetic models were correlated with the severity of CAD.

Expression of inflammatory factors and oxidative stress markers in serum of patients with coronary heart disease and correlation with coronary artery calcium score

Expression characteristics of inflammatory factors interleukin-23 and interleukin-35; oxidative stress markers of malondialdehyde, which is a final product of lipid peroxidation; superoxide dismutase; microRNA-126 and microRNA-146a in serum of patients with coronary heart disease were investigated. Correlation between these biomarkers and CACS (calcification score), as well as the underlying clinical significance were evaluated. A total of 192 patients diagnosed with coronary heart disease were recruited as the observation group, and 69 healthy adults who provided their blood samples were selected as the control group. Enzyme linked immunosorbent assay was carried out to measure the levels of inflammatory factors interleukin-23 and interleukin-35, and the levels of oxidative stress markers of malondialdehyde and superoxide dismutase in serum of the patients and healthy subjects. Real-time fluorescence-based quantitative PCR was performed to measure the expression levels of microRNA-126 and microRNA-146a in serum. The differences in expression of these biomarkers were analyzed, and correlation between these biomarkers and coronary artery calcium score were assessed. The differences in expression levels of interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a were statistically significant in both groups. The expression levels of interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a in the observation group were closely associated with severity of the disease. There were positive correlations between coronary artery calcium score and interleukin-23, interleukin-35, malondialdehyde, microRNA-126 and microRNA-146a, respectively; while a negative correlation existed between coronary artery calcium score and superoxide dismutase in the observation group. In conclusion, biomarkers interleukin-23, interleukin-35, malondialdehyde, superoxide dismutase, microRNA-126 and microRNA-146a were abnormally expressed in serum of patients with coronary heart disease, implicating their association with onset and progression of the disease. The biomarkers were found to be correlated with coronary artery calcium score. Detection of changes of related biomarkers in serum may have certain value in diagnosis of disease formation, as well as assessment of disease severity.

An evidence of brain-heart disorder: mental stress-induced myocardial ischemia regulated by inflammatory cytokines

OBJECTIVE

Underlying Coronary Artery Disease (CAD) complicated by Mental Stress-Induced Myocardial Ischemia (MSIMI) has been linked with an increased risk for adverse cardiovascular events and even sudden death. However, the underlying mechanisms of MSIMI remain unknown. In this study, we investigated cytokine levels at baseline inflammation status and during acute inflammatory responses to mental stress in patients with known CAD who presented with MSIMI.

METHOD

77 patients with known CAD were recruited and all underwent echocardiography before and during arithmetic stress task. MSIMI was diagnosed by new or worsening wall motion abnormalities greater than or equal to a 5% reduction of left ventricle ejection fraction. Inflammatory markers were measured both before and immediately after the Mental Stress (MS) by ELISA kits. Repeated measures models were used to report the responses and mixed linear regression models were used to report the differences between MSIMI negative and positive patients.

RESULT

MS induced a significant increase in Stromal Cell-Derived Factor-1α (SDF-1α) and Monocyte Chemoattractant Protein-1 (MCP-1) in all subjects; 20.78% of the patients with known CAD developed MSIMI during the arithmetic task. MSIMI positive patients had significantly lower baseline levels of Interleukin-1β (IL-1β) and Tumor Necrosis Factor-α (TNF-α), but a higher response in levels of SDF-1α than MSIMI negative patients.

CONCLUSION

MS can induce acute inflammatory responses. MSIMI is associated with lower levels of IL-1β and TNF-α at baseline and higher levels of SDF-1α in response to MS.

No association between interleukin-18 levels and risk of cardiovascular disease: A Mendelian randomization study

OBJECTIVE

In this study, Mendelian randomization method was used to determine whether there was a causal association between inflammatory cytokine IL-18 and cardiovascular disease risk.

METHODS

We performed a meta-analysis to evaluate the association between IL-18-137G/C and -607C/A polymorphisms and phenotype of IL-18 levels, and also the risks of CVD. All the literatures were searched before September 30, 2019. The logistic regression and linear regression were used to evaluate between IL-18 level and the risk of CVDs.

RESULT

Twelve eligible articles of the association between IL-18-137G/C and CVD risks and 8 eligible literatures related to IL-18-607C/A and CVD risks; 2 qualified literatures of the association between IL-18 SNPs and IL-18 levels and 4 eligible literatures related to IL-18 levels and CVD risks. Data of 4 literatures on the correlation between IL-18 level and CVD were summarized. Compared with patients with CVD, the mean of IL-18 level in the normal group was significantly decreased by 50.844 pg/ml (P < 0.05). But the association between IL-18-137G/C, IL-18-607C/A and CVD were not significant (P > 0.05), and the association between IL-18-607C/A and IL-18 level was also not significant (P > 0.05), Mendelian randomization study was failed to prove the association between IL-18 level and CVD risk.

CONCLUSION

This study does not support a causal association between IL-18 level and the risks of CVD.