Association of serum IgG4 and soluble interleukin-2 receptor levels with epicardial adipose tissue and coronary artery calcification

Lipoprotein (a) and coronary artery calcification: prospective study assessing interactions with other risk factors

BACKGROUND

Elevated plasma lipoprotein (a) [Lp(a)] and coronary artery calcification (CAC) are established cardiovascular risk factors that correlate with each other. We hypothesized that other cardiovascular risk factors could affect their relationship.

METHODS

We tested for interactions of 24 study variables related to dyslipidemia, diabetes, insulin resistance, hypertension, inflammation and coagulation with baseline Lp(a) on change in CAC volume and density over 9.5 years in 5975 Multi-Ethnic Study of Atherosclerosis (MESA) participants, free of apparent cardiovascular disease at baseline.

RESULTS

Elevated Lp(a) was associated with larger absolute increase in CAC volume (3.21 and 4.45 mm3/year higher for Lp(a) ≥30 versus <30 mg/dL, and Lp(a) ≥50 versus <50 mg/dL, respectively), but not relative change in CAC volume. No association was found with change in CAC density when assessing continuous ln-transformed Lp(a). The association between elevated Lp(a) (≥30 mg/dL) and absolute change in CAC volume was greater in participants with higher circulating levels of interleukin-2 soluble receptor α, soluble tumor necrosis factor alpha receptor 1 and fibrinogen (15.33, 11.81 and 7.02 mm3/year in quartile 4, compared to -3.44, -0.59 and 1.91 mm3/year in quartile 1, respectively). No significant interaction was found for other study variables. Similar interactions were seen when assessing Lp(a) levels ≥50 mg/dL.

CONCLUSIONS

Elevated Lp(a) was associated with an absolute increase in CAC volume, especially in participants with higher levels of selected markers of inflammation and coagulation. These results suggest Lp(a) as a potential biomarker for CAC volume progression.

Comprehensive analysis of differential immunocyte infiltration and the potential ceRNA networks during epicardial adipose tissue development in congenital heart disease

Background

To detect the development, function and therapeutic potential of epicardial adipose tissue (EAT); analyze a related gene expression dataset, including data from neonates, infants, and children with congenital heart disease (CHD); compare the data to identify the codifferentially expressed (DE) mRNAs and lncRNAs and the corresponding miRNAs; generate a potential competitive endogenous RNA (ceRNA) network; and assess the involvement of immunocyte infiltration in the development of the EAT.

Methods

Multiple algorithms for linear models for microarray data algorithms (LIMMA), CIBERSORT, gene-set enrichment analysis (GSEA), and gene set variation analysis (GSVA) were used. The miRcode, miRDB, miRTarBase, and TargetScan database were used to construct the ceRNA network. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the DE mRNAs were performed.

Results

Thirteen co-DE mRNAs and 47 co-DE lncRNAs were subsequently identified. The related categories included negative regulation of myoblast differentiation, regulation of ion transmembrane transport, and heart development, which were primarily identified for further pathway enrichment analysis. Additionally, the hub ceRNA network in EAT development involving MIR210HG, hsa-miR-449c-5p, and CACNA2D4 was generated and shown to target monocyte infiltration.

Conclusion

These findings suggest that the pathways of myoblast differentiation and ion transmembrane transport may be potential hub pathways involved in EAT development in CHD patients. In addition, the network includes monocytes, MIR210HG, and CACNA2D4, which were shown to target the RIG-I-like receptor signaling pathway and PPAR signaling pathway, indicating that these factors may be novel regulators and therapeutic targets in EAT development.

Interplay between epicardial adipose tissue, metabolic and cardiovascular diseases

Cardiovascular disease is the primary cause of death in obese and diabetic patients. In these groups of patients, the alterations of epicardial adipose tissue (EAT) contribute to both vascular and myocardial dysfunction. Therefore, it is of clinical interest to determine the mechanisms by which EAT influences cardiovascular disease. Two key factors contribute to the tight intercommunication among EAT, coronary arteries and myocardium. One is the close anatomical proximity between these tissues. The other is the capacity of EAT to secrete cytokines and other molecules with paracrine and vasocrine effects on the cardiovascular system. Epidemiological studies have demonstrated that EAT thickness is associated with not only metabolic syndrome but also atherosclerosis and heart failure. The evaluation of EAT using imaging modalities, although effective, presents several disadvantages including radiation exposure, limited availability and elevated costs. Therefore, there is a clinical interest in EAT as a source of new biomarkers of cardiovascular and endocrine alterations. In this review, we revise the mechanisms involved in the protective and pathological role of EAT and present the molecules released by EAT with greater potential to become biomarkers of cardiometabolic alterations.

Immunoglobulin G4-related Coronary Periarteritis and Luminal Stenosis in a Patient with a History of Autoimmune Pancreatitis

Immunoglobulin G4 (IgG4)-related disease is a systemic inflammatory disorder that was first described in patients with autoimmune pancreatitis. Although IgG4-related disease is thought to involve the cardiovascular system, case reports describing coronary artery involvement are relatively rare. We describe a patient who was previously diagnosed with autoimmune pancreatitis and found to have coronary periarteritis and luminal narrowing. After the initiation of steroid treatment, the patient's coronary periarteritis and luminal stenosis were both ameliorated with an improvement in the serum IgG4 concentration. The present findings collectively suggest that IgG4-related immuno-inflammation may have a role in the development of coronary periarteritis and luminal atherosclerosis.

Association between plasma proprotein convertase subtisilin/kexin type 9 concentration and coronary artery calcification

Background

Plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) has been reported to be related to several risk factors and diseases such as inflammatory markers and coronary artery disease. The aim of present study was to investigate whether plasma PCSK9 concentration was associated with coronary artery calcification.

Methods

A total of 403 consecutive untreated patients with angina-like chest pain, who received electron beam computed tomography, were enrolled and a coronary artery calcification score (CACS) was also measured. The baseline clinical characteristics were collected and blood sample was taken after 12-h fasting. The plasma PCSK9 concentrations were determined by ELISA in all patients, and the relationship between plasma PCSK9 concentrations and CACS was investigated.

Results

Patients with coronary artery calcification (CACS > 0) had significant higher plasma PCSK9 concentrations compared with those (CACS = 0) without coronary artery calcification (258.58 ± 69.53 ng/mL vs. 202.53 ± 52.17 ng/mL, P < 0.001). Patients with highest PCSK9 concentrations had the highest CACS. Multivariable linear regression analysis suggested that PCSK9 was independently associated with coronary artery calcification ( P = 0.002) after adjusting for traditional cardiovascular risk factors. Furthermore, the area under the curve for the plasma PCSK9 concentration in predicting coronary artery calcification was 0.736 (95% CI: 0.687–0.785, P < 0.001), with a sensitivity of 66% and specificity of 70%.

Conclusion

A positive association between plasma PCSK9 concentration and coronary artery calcification in untreated patients with angina-like chest pain was observed in our study, suggesting that further investigation may be needed in order to confirm our primary findings and explore the clinical implications.

High cut-off dialysis in chronic haemodialysis patients reduces serum procalcific activity

BACKGROUND

Vascular calcification is enhanced in chronic dialysis patients, possibly due to the insufficient removal of various intermediate molecular weight uraemic toxins such as interleukins with conventional membranes. In this study, we assessed the modulation of in vitro vascular calcification with the use of high cut-off (HCO) membranes in chronic dialysis patients.

METHODS

In a PERCI trial, 43 chronic dialysis patients were treated with conventional high-flux and HCO filters for 3 weeks in a randomized order following a 2-period crossover design. After each phase, serum predialysis samples were drawn. Calcifying human coronary vascular smooth muscle cells (VSMCs) were incubated with the patient's serum samples. Calcification was assessed with alkaline phosphatase (ALP) and alizarin red staining. In the clinical trial, HCO dialysis reduced the serum levels of the soluble tumour necrosis factor receptor (sTNFR) 1 and 2, vascular cell adhesion molecule 1 (VCAM-1) and soluble interleukin-2 receptor (sIL2R). We therefore investigated the in vitro effects of these mediators on vascular calcification.

RESULTS

VSMCs incubated with HCO dialysis serum showed a 26% reduction of ALP with HCO serum compared with high-flux serum. Alizarin was 43% lower after incubation with the HCO serum compared with the high-flux serum. While sIL2R and sTNFR 1 and 2 showed no effects on VSMC calcification, VCAM-1 caused a dose-dependent enhancement of calcification.

CONCLUSIONS

The use of HCO dialysis membranes in chronic dialysis patients reduces the procalcific effects of serum on VSMC in vitro. The mechanisms of the strong effect of HCO on in vitro calcification are not completely understood. One factor may be lower levels of VCAM-1 in HCO serum samples, since VCAM-1 was able to induce vascular calcification in our experiments. Neither sTNFR 1, sTNFR 2 nor sIL2R enhance vascular calcification in vitro. Regardless of the mechanisms, our results encourage further studies of highly permeable filters in chronic dialysis patients.

Relationship between serum IgG4 concentrations and atherosclerotic coronary plaques assessed by computed tomographic angiography

BACKGROUND

Immunoglobulin G4 (IgG4)-related immuno-inflammation has been suggested to affect the development of coronary artery atherosclerosis. The aim of this study was to analyze the association of serum IgG4 concentrations with calcified and non-calcified coronary plaques.

METHODS

Serum IgG4 concentrations were measured in 263 patients who underwent 320-slice coronary computed tomographic (CT) angiography. Vulnerable coronary plaques were evaluated for CT plaque characteristics, including low-density plaque (LDP), positive remodeling, and spotty calcification.

RESULTS

Serum concentrations of IgG4 were significantly higher in patients with non-calcified plaque (NCP) than in those without (32.2mg/dL vs. 23.7mg/dL, p=0.029). By contrast, the median serum IgG4 concentrations in patients with and without calcified plaque were 31.2mg/dL and 26.2mg/dL, respectively (p=0.107). Serum IgG4 concentrations were significantly elevated in patients with LDP (33.5mg/dL vs. 26.9mg/dL, p=0.002) and in those with positive remodeling (31.4mg/dL vs. 28.4mg/dL, p=0.039) than in those without. Patients with spotty calcification also had significantly higher serum IgG4 concentrations than those without (32.1mg/dL vs. 24.9mg/dL, p=0.049). In age- and gender-adjusted logistic regression analysis, the highest IgG4 quartile (≥56.7mg/dL) was significantly associated with LDP with an odds ratio of 2.49 (95% CI, 1.15-5.36, p=0.020).

CONCLUSIONS

Serum IgG4 concentrations were significantly associated with NCP, especially with LDP, suggesting that IgG4-related immuno-inflammation may play a role in coronary plaque vulnerability.