Cytomegalovirus infection is associated with elevated interleukin-10 in coronary artery disease

The global prevalence of Chlamydia pneumoniae, Helicobacter pylori, Cytomegalovirus and Herpes simplex virus in patients with coronary artery disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Coronary Artery Disease (CAD) is one of the most important causes of death worldwide. The aim of this study was to determine the prevalence of C. pneumoniae, H. pylori, Cytomegalovirus (CMV) and Herpes simplex virus (HSV) in CAD patients based on published serological and molecular studies.

METHODS

A systematic literature search was conducted in Medline (via PubMed), Embase, Scopus and Web of Science databases (1996-2019). Both molecular and serological studies were analyzed using STATA software (Version 14).

RESULTS

145 studies were included for final analysis. We gathered and investigated the prevalence of C. pneumoniae (25.1% [95% confidence interval (CI) 21.5-28.8%]), H. pylori (12.8% [(95% CI) 4.0-22.0%]), CMV (64.4% [(95% CI) 57.7-73.0%]) and HSV (31.8% [(95% CI) 21.5-42.2%]) in CAD patients from the analysis of molecular studies. Additionally, in serological studies, the prevalence of mentioned pathogens were 72.7% [(95% CI) 67.8-77.6%], 63.3% [(95% CI) 60.0-66.5%], 62.2% [(95% CI) 58.0-66.3%] and 34.3% [(95% CI) 23.6-45.1%] respectively.

CONCLUSION

Interestingly, there was only a significant increase in the prevalence of C. pneumoniae and H. pylori in serological studies compared to the reported data from molecular studies, while the prevalence of CMV and HSV were the same in both types of studies.

Human Cytomegalovirus Interleukin 10 Homologs: Facing the Immune System

Human Cytomegalovirus (HCMV) can cause a variety of health disorders that can lead to death in immunocompromised individuals and neonates. The HCMV lifecycle comprises both a lytic (productive) and a latent (non-productive) phase. HCMV lytic infection occurs in a wide range of terminally differentiated cell types. HCMV latency has been less well-studied, but one characterized site of latency is in precursor cells of the myeloid lineage. All known viral genes are expressed during a lytic infection and a subset of these are also transcribed during latency. The UL111A gene which encodes the viral IL-10, a homolog of the human IL-10, is one of these genes. During infection, different transcript isoforms of UL111A are generated by alternative splicing. The most studied of the UL111A isoforms are cmvIL-10 (also termed the "A" transcript) and LAcmvIL-10 (also termed the "B" transcript), the latter being a well-characterized latency associated transcript. Both isoforms can downregulate MHC class II, however they differ in a number of other immunomodulatory properties, such as the ability to bind the IL10 receptor and induce signaling through STAT3. There are also a number of other isoforms which have been identified which are expressed by differential splicing during lytic infection termed C, D, E, F, and G, although these have been less extensively studied. HCMV uses the viral IL-10 proteins to manipulate the immune system during lytic and latent phases of infection. In this review, we will discuss the literature on the viral IL-10 transcripts identified to date, their encoded proteins and the structures of these proteins as well as the functional properties of all the different isoforms of viral IL-10.

From vulnerable plaque to blood healthy therapy

Cardiovascular atherosclerotic disease is the leading cause of death in China and in Western nations. People with plaque or stenosis in the coronary artery or the carotid artery are the most susceptible population to suffer from acute events. Current investigations showed that plaque with the characteristics of intra-plaque hemorrhage or a thin cap with a large lipid core was causally associated with vulnerable plaque and plaque rupture. Of the many plaque ruptures occurring in patients with atherosclerotic disease, very few will trigger symptomatic events, rendering it exceedingly difficult to predict adverse outcomes. The assumption that identifying lesions prone to rupture will prevent acute coronary events was unrealistic. Factors in blood, especially those risk factors associated with thrombosis, play an important role as a bridge between plaque rupture and subsequent clinical events. Since there is little management to efficiently decrease the frequency of plaque rupture or erosion, blood healthy therapy, as a therapeutic apheresis to decrease the blood hypercoagulability to modulate the blood to be thrombosis resisting, should be considered as a potential therapeutic approach to reducing the incidence of acute coronary syndrome and stroke.

Human cytomegalovirus infection and vascular disease risk: A meta-analysis

BACKGROUND

Human cytomegalovirus (HCMV) infection has been associated with the acceleration of vascular disease. Numbers studies were conducted to analyze the association between HCMV infection and risk of vascular disease, but no clear consensus had been reached. The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis.

METHODS

We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they fulfilled all of the following selection criteria: (1) evaluating the association between HCMV infection and vascular disease; (2) case-control studies or nested case-control studies; (3) and supply the numbers (or percentage) of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators. Ultimately, We included data from 68 studies, which altogether enrolled 12027 cases and 15386 controls from 24 countries.

RESULTS

HCMV IgG was detected 7376 in 10611 cases, HCMV IgM was detected 153 in 1486 cases and HCMV DNA was detected 654 in 2139 cases. Overall, people exposed to HCMV infection had higher risk than those not exposed for vascular disease (OR 1.70 [95% CI 1.43-2.03] IgG-based HCMV tests, 2.88 [95% CI 1.87-4.43] IgM-based HCMV tests and 2.56 [95% CI 1.46-4.49 PCR-based HCMV tests]). HCMV infection was clearly identified as a risk factor for vascular disease in Asian group, Caucasian group and other group, especially Asian group(OR 1.86 [95% CI 1.33-2.60] IgG-based HCMV tests, 3.57 [95% CI 1.94-6.60] IgM-based HCMV tests and 4.09 [95% CI 3.10-5.40 PCR-based HCMV tests]).

CONCLUSION

This meta-analysis suggested that HCMV infection is associated with an increased risk for vascular disease.

Infection and Stroke: an Update on Recent Progress

The role of infection in cerebrovascular disease is complex and remains incompletely understood. Over the last 5 years, investigators have made notable inroads in untangling this thorny topic. In this review, we examine these recent developments, concentrating on four aspects of the relationship between infection and stroke. We first discuss specific infectious agents as direct causes of stroke, focusing on recent work implicating herpesviruses and HIV in cerebral vasculopathy. We then discuss systemic infection of any type as a stroke trigger, focusing on the relationship of infection to timing of acute stroke, both in children and adults, as well as the role of vaccination in stroke prevention. We examine the evidence for chronic infection or "infectious burden" as a stroke risk factor. Finally, we discuss recent work on infection as a risk factor for increased morbidity after stroke, possible mechanisms mediating this effect, and the evidence for prophylactic antibiotics.

Cytomegalovirus infection and coronary heart disease risk: a meta-analysis

The chronic inflammatory process including cytomegalovirus (CMV) infection has been hypothesized to induce the progression of atherosclerosis in coronary heart disease (CHD). Numbers studies were conducted to analyze the association between CMV infection and risk of CHD, but no clear consensus had been reached. To assess this relationship more precisely, a meta-analysis was performed. The electronic databases PubMed, Embase, and CNKI were searched; data were extracted and analyzed independently by two investigators. Ultimately, 55 studies, involving 9,000 cases and 8,608 controls from six prospective studies (all with a nested case-control design) and 49 retrospective case-control studies were included. Overall, people exposed to CMV infection had an odds ratio (OR) of 1.67 (95% CI, 1.56-1.79) for CHD risk, relative to those not exposed. CMV infection was clearly identified as a risk factor for CHD in both prospective studies (OR, 1.31; 95% CI, 1.132-1.517) and retrospective studies (OR, 1.79; 95% CI, 1.659-1.939), and in both Asian group (OR, 2.69; 95% CI, 2.304-3.144) and non-Asian group (OR, 1.48; 95% CI, 1.371-1.600). Interestingly, in the subgroup analyses by detection methods of CMV, the increased risk (OR, 8.121) was greater among studies using polymerase chain reaction than the risk (OR, 1.561) among studies using enzyme-linked immunosorbent assay. In conclusion, this meta-analysis suggested that CMV infection is associated with an increased risk for CHD, especially among Asian populations.

Antigen-induced immunomodulation in the pathogenesis of atherosclerosis

Atherosclerosis is a chronic inflammatory disorder characterised by the accumulation of monocytes/macrophages, smooth muscle cells, and lymphocytes within the arterial wall in response to the release of proinflammatory molecules. Such accumulation results in the formation of the atherosclerotic plaque, which would eventually evolve to complications such as total artery occlusion, rupture, calcification, or aneurysm. Although the molecular mechanism responsible for the development of atherosclerosis is not completely understood, it is clear that the immune system plays a key role in the development of the atherosclerotic plaque and in its complications. There are multiple antigenic stimuli that have been associated with the pathogenesis of atherosclerosis. Most of these stimuli come from modified self-molecules such as oxidised low-density lipoproteins (oxLDLs), beta2glycoprotein1 (β2GP1), lipoprotein a (LP(a)), heat shock proteins (HSPs), and protein components of the extracellular matrix such as collagen and fibrinogen in the form of advanced glycation-end (AGE) products. In addition, several foreign antigens including bacteria such as Porphyromonas gingivalis and Chlamydia pneumoniae and viruses such as enterovirus and cytomegalovirus have been associated with atherosclerosis as potentially causative or bystander participants, adding another level of complexity to the analysis of the pathophysiology of atherosclerosis. The present review summarises the most important scientific findings published within the last two decades on the importance of antigens, antigen stimulation, and adaptive immune responses in the development of atherosclerotic plaques.

Usefulness of Interleukin-10 Detection in Lung Transplant Patients With Human Cytomegalovirus Infection With Respect to Virus Persistence

BACKGROUND

Human cytomegalovirus (HCMV) infection in lung transplant patients induces an inflammatory response, including local production of cytokines involved in viral clearance. The aim of this study was to evaluate the potential value of monitoring interleukin (IL)-10 with respect to HCMV persistence in blood and/or bronchoalveolar lavage (BAL).

METHODS

A quantitative polymerase chain reaction assay was used for HCMV-DNA detection in plasma and BAL. IL-10 was measured with an enzyme-linked immunosorbent assay in blood and with BAL in 101 lung transplant patients. IL-10 levels were correlated with clinical outcome.

RESULTS

A total of 23 patients of 35 (66%) with detectable HCMV in plasma and/or BAL exhibited increased levels of IL-10 in plasma and/or BAL. Complete clearance of HCMV was observed after 168 (median 130) days in the IL-10-positive group (n=23) in comparison with 87 (median 58) days in the IL-10-negative group (n=12; P<0.024). In the seven HCMV-positive patients with positive IL-10 levels in BAL only, HCMV persisted in BAL for a median of 579 days without signs of systemic infection (positive plasma levels) or clinical symptoms.

CONCLUSIONS

We show that in lung transplant patients with elevated levels of IL-10 in plasma and/or BAL, HCMV clearance is prolonged because of the influence of anti-inflammatory cytokines.

Patients With Low High-Density Lipoprotein-Cholesterol or Smoking are More Likely to Develop Myocardial Infarction Among Subjects With a Visible Lesion or Stenosis in Coronary Artery

BACKGROUND

Traditional contrast coronary arteriography affords only an indirect view of aspects of atheromata related to their propensity to trigger thromboses, so it is urgent to recognize the vulnerable person who is more likely to develop myocardial infarction (MI) among patients with visible lesion or stenosis in coronary artery.

METHODS AND RESULTS

Two hundred and eighty-eight patients (144 MI patients, 144 controls) who had either a visible lesion or differing extent of stenosis in 1 or more major coronary arteries were consecutively enrolled. Lipid profile, C-reactive protein (CRP), smoking, hypertension, dyslipidemia and diabetes were analyzed for their association with MI. No differences in the prevalence of dyslipidemia, hypertension or diabetes was found between the patients with MI and those without, and CRP, triglycerides, total cholesterol and low-density lipoprotein-cholesterol levels did not differ between the 2 groups (all p>0.05). However, high-density lipoprotein-cholesterol (HDL-C) was significantly lower in the patients with MI than in those without (1.06+/-0.30 vs 1.14+/-0.32 mmol/L, p=0.024). On multivariate analysis after adjustment for age and gender, adjusted odds ratio (95% confidence interval) of MI was 0.44 (0.20-0.96) for HDL-C, p=0.038; 2.6 (1.48-4.56, p=0.001) for smoking, which indicated that high HDL-C was protective for MI, and smoking was associated with an increased risk of MI.

CONCLUSIONS

The present findings indicate that among subjects with a visible lesion or stenosis in coronary arteries, those with low HDL-C or smokers are more likely to develop MI.