Infections, inflammation, and the risk of coronary heart disease

Meta-analyses of four eosinophil related gene variants in coronary heart disease

The goal of our study is to assess the contribution of four eosinophil related gene variants (rs12619285, rs1420101, rs3184504 and rs4143832) to the risk of coronary heart disease (CHD). We conducted four meta-analyses of studies examining the association between four eosinophil related gene variants and the risk of CHD. A systematic search was conducted using MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI), Wanfang Chinese Periodical. A case-control study was conducted between 162 CHD cases and 119 non-CHD controls to explore their contribution to CHD. For rs3184504 of SH2B3 gene, the meta-analysis was performed among 19 study stages among 94,555 participants. Significant association between rs3184504 and CHD risk was observed in European and South Asian populations (OR = 1.13, 95% CI = 1.10-1.16, p < 0.0001, fixed-effect method). For the other SNPs (rs12619285, rs1420101, and rs4143832), we combined our case-control data with the previous studies and found no association of them with the risk of CHD. No significant contribution of the four genetic variants to CHD was observed in Han Chinese (p > 0.05). In conclusion, our results supported a significant association between rs3184504 of SH2B3 gene and the risk of CHD in Europeans and South Asians, although we were unable to observe association between the four variants and the risk of CHD in Han Chinese.

Menopausal hormone treatment cardiovascular disease: another look at an unresolved conundrum

Cardiovascular disease (CVD) is the most common cause of death in women. Before the Women's Health Initiative (WHI) hormone trials, evidence favored the concept that menopausal hormone treatment (MHT) protects against CVD. WHI studies failed to demonstrate CVD benefit, with worse net outcomes for MHT versus placebo in the population studied. We review evidence regarding the relationship between MHT and CVD with consideration of mechanisms and risk factors for atherogenesis and cardiac events, results of observational case-control and cohort studies, and outcomes of randomized trials. Estrogen effects on CVD risk factors favor delay or amelioration of atherosclerotic plaque development but may increase risk of acute events when at-risk plaque is present. Long-term observational studies have shown ∼40% reductions in risk of myocardial infarction and all-cause mortality. Analyses of data from randomized control trials other than the WHI show a ∼30% cardioprotective effect in recently menopausal women. Review of the literature as well as WHI data suggests that younger and/or more recently menopausal women may have a better risk-benefit ratio than older or remotely menopausal women and that CVD protection may only occur after >5 years; WHI women averaged 63 years of age (12 years postmenopausal) and few were studied for >6 years. Thus, a beneficial effect of long-term MHT on CVD and mortality is still an open question and is likely to remain controversial for the foreseeable future.

Human cytomegalovirus-encoded miR-US25-1 aggravates the oxidised low density lipoprotein-induced apoptosis of endothelial cells

Human cytomegalovirus (HCMV) infection is linked to the development and severity of the cardiovascular disease atherosclerosis; however, there is little known about the promotion of atherosclerosis. miR-US25-1 is one of HCMV-encoded miRNAs and targets cellular genes that are essential for virus growth to control the life cycle of the virus and host cells. The prominent regulation on cell cycle genes of the miR-US25-1 attracts us to explore its role in the atherosclerosis promotion. It was indicated that miR-US25-1 level was upregulated in subjects or in endothelial cells with HCMV infection; and the miR-US25-1 downregulated the expression of BRCC 3 by targeting the 5′ UTR of BRCC 3. And a miR-US25-1 mimics transfection could reduce the EAhy926 cell viability but did not induce apoptosis in EAhy926 cells. And what is more, miR-US25-1 mimicis transfection deteriorated the ox-LDL-induced apoptosis and aggravated the upregulation of apoptosis-associated molecules by oxidised low density lipoprotein (ox-LDL) in EAhy926 cells. And we have also confirmed the deregulation of BRCC 3 expression by miR-US25-1 by targeting the 5′ UTR of it. Given the vital role of BRCC 3 in DNA damage repairing, we speculated that the targeting inhibition of BRCC 3 by miR-US25-1 may contribute to the aggravation of ox-LDL-promoted apoptosis of endothelial EAhy926 cells.

Impact of viral and bacterial infections in coronary artery disease patients

Atherosclerosis is becoming an alarming disease for the existence of healthy human beings in the 21^st century. There are a growing number of agents, either modernized life style generated, competitive work culture related or infection with some bacterial or viral agents, documented every year. These infectious agents do not have proper diagnostics or detection availability in many poor and developing countries. Hence, as active medical researchers, we summarize some aspects of infectious agents and their related mechanisms in this review which may be beneficial for new beginners in this field and update awareness in the field of cardiovascular biology.

High incidence of Aggregatibacter actinomycetemcomitans infection in patients with cerebral infarction and diabetic renal failure: a cross-sectional study

BACKGROUND

Recent epidemiological studies suggest that periodontitis is a major risk factor for renal failure and cerebral infarction. The aim of this study was to evaluate the association among periodontitis, renal failure, and cerebral infarction, focusing on microbiological and immunological features.

METHODS

Twenty-one patients treated with hemodialysis (HD) were enrolled in this study. They were 8 with diabetic nephropathy and 13 with non-diabetic nephropathy. Blood examination, periodontal examination, brain magnetic resonance image (MRI), and dental radiography were performed on all patients. Subgingival plaque, saliva, and blood samples were analyzed for the periodontal pathogens, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), and Prevotella intermedia (P. intermedia) using quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that the patients with diabetic nephropathy had more A. actinomycetemcomitans compared with non-diabetic nephropathy (P = 0.038) in dental plaque. Furthermore, the patients with diabetic nephropathy showed a significantly higher incidence of cerebral infarction compared with those with non-diabetic nephropathy (P = 0.029). Clinical oral and radiographic scores tended to be higher among patients in the diabetic nephropathy group than in the non-diabetic nephropathy group.

CONCLUSIONS

Periodontal pathogens, particularly A. actinomycetemcomitans, may play a role, at least a part, in the development of cerebral infarction in Japanese HD patients with diabetic nephropathy.

The connection between ruptured cerebral aneurysms and odontogenic bacteria

BACKGROUND

Patients with ruptured saccular intracranial aneurysms have excess long-term mortality due to cerebrovascular and cardiovascular diseases compared with general population. Chronic inflammation is detected in ruptured intracranial aneurysms, abdominal aortic aneurysms and coronary artery plaques. Bacterial infections have been suggested to have a role in the aetiology of atherosclerosis. Bacteria have been detected both in abdominal and coronary arteries but their presence in intracranial aneurysms has not yet been properly studied.

OBJECTIVE

The aim of this preliminary study was to assess the presence of oral and pharyngeal bacterial genome in ruptured intracranial aneurysms and to ascertain if dental infection is a previously unknown risk factor for subarachnoid haemorrhage.

METHODS

A total of 36 ruptured aneurysm specimens were obtained perioperatively in aneurysm clipping operations (n=29) and by autopsy (n=7). Aneurysmal sac tissue was analysed by real time quantitative PCR with specific primers and probes to detect bacterial DNA from several oral species. Immunohistochemical staining for bacterial receptors (CD14 and toll-like receptor-2 (TLR-2)) was performed from four autopsy cases.

RESULTS

Bacterial DNA was detected in 21/36 (58%) of specimens. A third of the positive samples contained DNA from both endodontic and periodontal bacteria. DNA from endodontic bacteria were detected in 20/36 (56%) and from periodontal bacteria in 17/36 (47%) of samples. Bacterial DNA of the Streptococcus mitis group was found to be most common. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Treponema denticola were the three most common periodontal pathogens. The highly intensive staining of CD14 and TLR-2 in ruptured aneurysms was observed.

CONCLUSIONS

This is the first report showing evidence that dental infection could be a part of pathophysiology in intracranial aneurysm disease.

Genome-wide association study of gene by smoking interactions in coronary artery calcification

Many GWAS have identified novel loci associated with common diseases, but have focused only on main effects of individual genetic variants rather than interactions with environmental factors (GxE). Identification of GxE interactions is particularly important for coronary heart disease (CHD), a major preventable source of morbidity and mortality with strong non-genetic risk factors. Atherosclerosis is the major cause of CHD, and coronary artery calcification (CAC) is directly correlated with quantity of coronary atherosclerotic plaque. In the current study, we tested for genetic variants influencing extent of CAC via interaction with smoking (GxS), by conducting a GxS discovery GWAS in Genetic Epidemiology Network of Arteriopathy (GENOA) sibships (N = 915 European Americans) followed by replication in Framingham Heart Study (FHS) sibships (N = 1025 European Americans). Generalized estimating equations accounted for the correlation within sibships in strata-specific groups of smokers and nonsmokers, as well as GxS interaction. Primary analysis found SNPs that showed suggestive associations (p≤10⁻⁵) in GENOA GWAS, but these index SNPs did not replicate in FHS. However, secondary analysis was able to replicate candidate gene regions in FHS using other SNPs (+/−250 kb of GENOA index SNP). In smoker and nonsmoker groups, replicated genes included TCF7L2 (p = 6.0×10⁻⁵) and WWOX (p = 4.5×10⁻⁶); and TNFRSF8 (p = 7.8×10⁻⁵), respectively. For GxS interactions, replicated genes included TBC1D4 (p = 6.9×10⁻⁵) and ADAMTS9 (P = 7.1×10⁻⁵). Interestingly, these genes are involved in inflammatory pathways mediated by the NF-κB axis. Since smoking is known to induce chronic and systemic inflammation, association of these genes likely reflects roles in CAC development via inflammatory pathways. Furthermore, the NF-κB axis regulates bone remodeling, a key physiological process in CAC development. In conclusion, GxS GWAS has yielded evidence for novel loci that are associated with CAC via interaction with smoking, providing promising new targets for future population-based and functional studies of CAC development.

Early life exposure to the 1918 influenza pandemic and old-age mortality by cause of death

OBJECTIVES

We sought to analyze how early exposure to the 1918 influenza pandemic is associated with old-age mortality by cause of death.

METHODS

We analyzed the National Health Interview Survey (n = 81,571; follow-up 1989-2006; 43,808 deaths) and used year and quarter of birth to assess timing of pandemic exposure. We used Cox proportional and Fine-Gray competing hazard models for all-cause and cause-specific mortality, respectively.

RESULTS

Cohorts born during pandemic peaks had excess all-cause mortality attributed to increased noncancer mortality. We found evidence for a trade-off between noncancer and cancer causes: cohorts with high noncancer mortality had low cancer mortality, and vice versa.

CONCLUSIONS

Early disease exposure increases old-age mortality through noncancer causes, which include respiratory and cardiovascular diseases, and may trigger a trade-off in the risk of cancer and noncancer causes. Potential mechanisms include inflammation or apoptosis. The findings contribute to our understanding of the causes of death behind the early disease exposure-later mortality association. The cancer-noncancer trade-off is potentially important for understanding the mechanisms behind these associations.

Effect of a Probiotic Preparation (VSL#3) on CardiovascularRisk Parameters in Critically-Ill Patients

INTRODUCTION

Cardiovascular disease (CVD) counts for a major portion of morbidity and mortality globally mostly accompanied by lipid abnormalities. Being at increased risk of cardiac injury, critically ill patients suffer from various lipid disorders. Lipid homeostasis has been efficiently restored by the introduction of probiotics. The aim of this trial was to determine the effect of probiotics on inflammation, antioxidant capacity and lipid peroxidation in critically ill patients.

METHODS

Forty patients admitted to the intensive care unit were randomized to receive placebo or probiotic for 7 days. Serum levels of triglyceride (TG), total cholesterol, HDL-C, LDL-C and high- sensitivity C-reactive protein (hs-CRP) were measured before initiation of the study and on the 7(th) day.

RESULTS

There was a significant difference between two groups regarding the levels of TG, HDL and hs-CRP at the end of the study (P= 0.043, <0.001 and 0.003, respectively); however, there was not a significant difference in total cholesterol and LDL-C levels.

CONCLUSION

Administration of probiotics in critically ill patients reduced the levels of TG and hs-CRP and increased HDL-C levels. However, no significant change was detected in levels of total cholesterol or LDL-C.

Chlamydophila pneumoniae infection and cardiovascular disease

Atherosclerosis is a multifactorial vascular inflammatory process; however, the inciting cause for inflammation remains unclear. Two decades ago, Chlamydophila pneumoniae (formerly Chlamydia pneumoniae) infection was proposed as a putative etiologic agent. We performed a PubMed search using the keywords Chlamydia and atherosclerosis in a Boolean query to identify published studies on C. pneumoniae and its role in atherogenesis, and to understand research interest in this topic. We found 1,652 published articles on this topic between 1991 and 2011. We analyzed relevant published studies and found various serological, molecular, and animal modeling studies in the early period. Encouraged by positive results from these studies, more than a dozen antibiotic clinical-trials were subsequently conducted, which did not find clinical benefits of anti-Chlamydophila drug therapy. While many researchers believe that the organism is still important, negative clinical trials had a similar impact on overall research interest. With many novel mechanisms identified for atherogenesis, there is a need for newer paradigms in Chlamydophila-atherosclerosis research.

Differential identification of atypical pneumonia pathogens in aorta and internal mammary artery related to ankle brachial index and walking distance

BACKGROUND

We studied the existence of agents in aorta biopsies, such as Chlamydia pneumoniae, cytomegalovirus, and Mycoplasma pneumoniae, that are thought to have a role in atherosclerosis etiopathogenesis role, and their association with peripheral artery disease.

MATERIALS AND METHODS

We examined aorta wall and internal mammarian artery (IMA) biopsies taken from two different places in 63 patients in whom coronary artery bypass was performed. In these biopsies, we evaluated the deoxyribonuclease (DNA) of these microorganisms using polymerase chain reaction. From the same patients, we recorded the ankle brachial index, road walking distance information, lipid profile, C-reactive proteins, blood parameters such as fibrinogen, and the patient's operation data.

RESULTS

In the nine aorta biopsies taken from 63 patients, we isolated C pneumoniae DNA. In IMA biopsies taken from the same patients, we detected no microorganism DNA (P < 0.001). In the same aorta biopsies, we found no cytomegalovirus or M pneumoniae DNA. We examined 12 patients using an index value of 0.9 in the ankle brachial index evaluation; eight had C pneumoniae in the aorta biopsies (P < 0.001).

CONCLUSIONS

We found a significant relationship between C pneumoniae DNA and the existence of peripheral artery disease. In the development of atherosclerosis with C pneumoniae, there may be a determinant pathogen in both the aorta and the peripheral arteries. The nonexistence of C pneumoniae DNA in the IMA biopsies may indicate infectious agents because of the predominant endothelial functions in this artery, and thus its resistance to atherosclerosis.

Sleep duration, cardiovascular disease, and proinflammatory biomarkers

Habitual sleep duration has been associated with cardiometabolic disease, via several mechanistic pathways, but few have been thoroughly explored. One hypothesis is that short and/or long sleep duration is associated with a proinflammatory state, which could increase risk for cardiovascular and metabolic diseases. This hypothesis has been largely explored in the context of experimental sleep deprivation studies which have attempted to demonstrate changes in proinflammatory markers following acute sleep loss in the laboratory. Despite the controlled environment available in these studies, samples tend to lack generalization to the population at large and acute sleep deprivation may not be a perfect analog for short sleep. To address these limitations, population based studies have explored associations between proinflammatory markers and habitual sleep duration. This review summarizes what is known from experimental and cross-sectional studies about the association between sleep duration, cardiovascular disease, and proinflammatory biomarkers. First, the association between sleep duration with both morbidity and mortality, with a focus on cardiovascular disease, is reviewed. Then, a brief review of the potential role of proinflammatory markers in cardiovascular disease is presented. The majority of this review details specific findings related to specific molecules, including tumor necrosis factor-α, interleukins-1, -6, and -17, C-reactive protein, coagulation molecules, cellular adhesion molecules, and visfatin. Finally, a discussion of the limitations of current studies and future directions is provided.

Higher immunoglobulin G antibody levels against cytomegalovirus are associated with incident ischemic heart disease in the population-based EPIC-Norfolk cohort

BACKGROUND

Cytomegalovirus (CMV) is associated with ischemic heart disease (IHD) among organ transplant recipients. The relationship between the levels of antibody for CMV with IHD in immunocompetent individuals is uncertain.

METHODS

We measured baseline CMV immunoglobulin G (IgG) levels in 12,574 participants without IHD from the population-based EPIC-Norfolk cohort, aged 40-70 years old at recruitment in 1993-1997. Underlying causes of death or hospitalization until 31 March 2008 were abstracted from death certificates and a database of hospital admissions, respectively.

RESULTS

Of the participants, 58% were seropositive for CMV. After a mean follow-up of 12 years (standard deviation, 2.2 years), 1356 first-time IHD events occurred. After adjustment for classic IHD risk factors, belonging to the highest antibody group was associated with an increased risk of incident IHD, compared with seronegativity (hazard ratio, 1.22; 95% confidence interval, 1.05-1.42). After additional adjustment for measures of social class, inflammation, and possible confounders, this association was unchanged (hazard ratio, 1.21; 95% confidence interval, 1.04-11.41).

CONCLUSIONS

This is the first population study to show that CMV IgG antibody levels are related to incident IHD compared to seronegativity. Studies correlating CMV antibody levels with direct measurements of active infection will be necessary.

Clinical utility of inflammatory markers and advanced lipoprotein testing: advice from an expert panel of lipid specialists

The National Cholesterol Education Program Adult Treatment Panel guidelines have established low-density lipoprotein cholesterol (LDL-C) treatment goals, and secondary non-high-density lipoprotein (HDL)-C treatment goals for persons with hypertriglyceridemia. The use of lipid-lowering therapies, particularly statins, to achieve these goals has reduced cardiovascular disease (CVD) morbidity and mortality; however, significant residual risk for events remains. This, combined with the rising prevalence of obesity, which has shifted the risk profile of the population toward patients in whom LDL-C is less predictive of CVD events (metabolic syndrome, low HDL-C, elevated triglycerides), has increased interest in the clinical use of inflammatory and lipid biomarker assessments. Furthermore, the cost effectiveness of pharmacological intervention for both the initiation of therapy and the intensification of therapy has been enhanced by the availability of a variety of generic statins. This report describes the consensus view of an expert panel convened by the National Lipid Association to evaluate the use of selected biomarkers [C-reactive protein, lipoprotein-associated phospholipase A(2), apolipoprotein B, LDL particle concentration, lipoprotein(a), and LDL and HDL subfractions] to improve risk assessment, or to adjust therapy. These panel recommendations are intended to provide practical advice to clinicians who wrestle with the challenges of identifying the patients who are most likely to benefit from therapy, or intensification of therapy, to provide the optimum protection from CV risk.

Herpes simplex virus infection and risk of atrial fibrillation: a nationwide study

BACKGROUND

Currently, precise mechanisms of atrial fibrillation (AF) are uncertain but proved to be associated with inflammation. There has been no specific study to evaluate the risk of AF after diagnosis of herpes simplex virus (HSV) infection.

METHODS

To investigate the relationship between HSV infection and the occurrence of AF, we used a nation-wide population-based dataset from Taiwan. A total of 15,180 patients with diagnosis of HSV infection were included in the study group from a 1,000,000 sampling cohort dataset between January 2000 and December 2003. Another 73,197 age-, gender-, and comorbidity-matched subjects without HSV infection were included in the control group. The log-rank test was performed to analyze the differences in accumulated AF-free survival rates between these 2 groups. Cox proportional hazard regressions were performed to evaluate the independent factor in determining the longitudinal hazard of AF.

RESULTS

During a 3-year follow-up period, 240 patients from the study group (1.6%) and 801 patients from the comparison group (1.1%) had newly developed AF. The log-rank test showed that patients with HSV had significantly higher incidence of AF development than those without HSV (p<0.001). After Cox model adjustment for risk factors and comorbidities, HSV infection was independently associated with increased risk of AF development (hazard ratios [HR], 1.39; 95% confidence interval [CI], 1.2-1.60; p<0.0001).

CONCLUSION

Our study concludes that HSV infection may be independently associated with an increased risk of future AF development.

Association between HSV1 seropositivity and obesity: data from the National Health and Nutritional Examination Survey, 2007-2008

Background

Herpes simplex virus (HSV) is among the most common sexually transmitted pathogens in the United States and worldwide. HSV has a high incidence of undetected cases. In addition, there is no treatment, and there is a lack of knowledge why disparities among populations exist. Research studies suggest that fat tissue may participate in body's immune responses, and the impact of obesity on susceptibility to HSV1 infection is not clear. The purpose of this study was to examine whether obesity is a risk factor for HSV1 infection using a large sample from the general population.

Methods/Principal Findings

This cross-sectional study used data from the National Health and Examination and Nutritional Examination Survey (NHANES) from 2007–2008. Variables, gender, age, race/ethnicity, marital status, education, poverty level, and diabetes represented potential confounders and were included in analyses. The two-tailed Pearson's chi square, student's t test, and a multiple logistic regression analysis were applied to evaluate associations using a significance value of p≤0.05. Adjusted odds ratios with 95% confidence interval represented the degree of these associations. The prevalence of HSV1 infection in US population between 20 and 49 years old was 60.3% (n = 1,536). In this study, having a BMI classified as the obese group (BMI 30–39.9) was significantly associated with HSV1 infection before [unadjusted OR = 1.74 (95% CI 1.20–2.51), p = 0.006] and after controlling for socio-demographic factors [adjusted OR = 1.50 (95%CI 1.06–2.13)], p = 0.026]. This association was stronger than three already established risk factors of age, female gender, and poverty level.

Conclusions/Significance

This study provides evidence that obesity may play a role in the susceptibility to HSV1 infection. Findings from this study suggest that obesity should be considered when designing preventive measures for HSV1 infection. These results may also explain why some people acquire HSV1 infections and some do not. Further, these findings may justify an increased emphasis on the control and prevention of HSV1 transmission and other pathogens in overweight and obese populations.

Association of Helicobacter pylori infection with acute myocardial infarction

OBJECTIVES

Helicobacter pylori infection has been linked to cardiovascular diseases (CVD) and several studies have reported its positive association with inflammatory response after acute myocardial infarction (AMI). On account of the importance of the inflammatory process in the development of CVD, we decided to examine the seroprevalence of H. pylori, the prevalence of CVD risk in the more virulent strains bearing the cytotoxin-associated protein (CagA), and the changes in C-reactive protein (CRP) as an inflammatory marker in Iranian patients with AMI.

METHODS

A case-control study was designed to determine the seropositivity status of H. pylori and CagA in blood samples obtained from 500 patients with AMI and 500 control individuals without any evidence of clinical CVD. Serum and peripheral blood mononuclear cells were analyzed using the enzyme-linked immunosorbent assay and western blotting methods, respectively. CRP levels were also measured in all individuals.

RESULTS

The prevalence of H. pylori infection and CagA status were significantly higher among the patients with AMI than the controls (66 vs. 20% and 75.7 vs. 30%, respectively); the odds ratio was 2.57 (95% confidence interval 1.89-3.49). CRP levels were significantly different in the patients compared with the controls (5.02±1.04 mg/l vs. 2.41±0.9 mg/l, respectively).

CONCLUSION

Our results confirmed that the patients with AMI had a significantly higher prevalence of H. pylori infection and CagA seropositivity than the control population. Infection with H. pylori may influence AMI, which in our findings shows an association between H. pylori seropositivity and AMI through an inflammatory process.

The influence of persistent pathogens on circulating levels of inflammatory markers: a cross-sectional analysis from the Multi-Ethnic Study of Atherosclerosis

Background

Systemic inflammation is linked to cardiovascular risk, but the influence of persistent pathogens, which are conventionally dichotomously categorized, on circulating levels of inflammatory markers is not clear. Antibody levels of pathogens have not been examined in relation to inflammation.

Methods

Using data from a subsample of the Multi-Ethnic Study of Atherosclerosis, we examined circulating levels of interleukin-6 (IL-6), C-reactive protein (CRP) and fibrinogen in relation to five common persistent pathogens: cytomegalovirus, herpes simplex virus-1, Hepatitis A virus, Helicobacter pylori and Chlamydia pneumoniae. We tested the hypothesis that the number of seropositive pathogens (based on conventional cut-off points) would not be as sensitive a marker of inflammation as immune response measured by antibody levels to pathogens.

Results

High antibody response to multiple pathogens showed graded and significant associations with IL-6 (p < 0.001), CRP (p = 0.04) and fibrinogen (p = 0.001), whereas seropositive pathogen burden did not. In multiple linear regression models, high antibody response to multiple pathogens maintained a positive association only with IL-6 (4.4% per pathogen exhibiting high antibody response, 95% CI 0.0-8.9).

Conclusions

High antibody response to pathogens was a more consistent marker of inflammatory outcomes compared to seropositivity alone and high antibody response to multiple pathogens was a stronger marker compared to any single pathogen.

A multimarker approach for the prediction of coronary artery disease: cost-effectiveness analysis

OBJECTIVES

Coronary artery disease (CAD), as the leading cause of death, poses a huge economic burden on health-care systems. We used a multi-marker approach to explore discriminative abilities of several lipid, inflammatory, and oxidative stress/antioxidative defense markers as CAD predictors. We assessed their cost-effectiveness compared with the Framingham risk score (FRS).

METHODS

Using a decision model, we evaluated the costs, accuracy, and cost-effectiveness of each model. The FRS was used as the baseline model. Other models were formed with the consecutive addition of selected markers: apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), apolipoprotein (a) [apo(a)] isoform, lipoprotein (a), high-sensitivity C-reactive protein, malondialdehyde, superoxide dismutase (SOD), sulfhydryl, and superoxide anion (O(2) (-) ). A best-case model was formed from a combination of diagnostic markers to yield the best patient stratification algorithm. All models were assessed by their predictive probabilities using receiver operating characteristic curves. To accomplish our goals, we recruited 188 CAD patients (verified by coronary angiography) and 197 asymptomatic CAD-free subjects for comparison. The analysis was performed from a third-party payer perspective.

RESULTS

Only two strategies had outstanding discriminative abilities: the best-case model (FRS, SOD, and O(2) (-) ) and FRS plus SOD with area under the curve (AUC) values of 0.924 and 0.906, respectively. The cost-effectiveness ratio varied between €593 per AUC for the baseline model to €2425 per AUC for FRS plus apo(a) isoform. Strategies involving oxidative stress/antioxidative defense markers were more cost-effective than strategies involving lipid or inflammatory markers. All results were robust.

CONCLUSION

Our results support the feasibility of a multimarker approach for CAD screening. The introduction of oxidative stress/antioxidative defense markers in the clinical laboratory would be convenient and cost-effective.

Joint effect of self-reported sleep problems and three components of the metabolic syndrome on risk of coronary heart disease

OBJECTIVE

This study explored the joint effect of two epidemics, sleep problems and metabolic syndrome (MetS), on the risk of coronary heart disease (CHD).

METHODS

The study group is part of the Finnish middle-aged men who participated in the first screening for the Helsinki Heart Study (HHS) in 1981-1982. At that time, three components of MetS were measured: body mass index, HDL cholesterol, and blood pressure. Later, in 1986-1988, they were given a psychosocial questionnaire including items on sleep problems. Of the respondents, 2753 formed our study group and were followed up using population-based registers until 1995. The relative risks (RR) of CHD were estimated using Cox's regression models.

RESULTS

When several sleep problems were present simultaneously, some increased CHD risk was observed. However, when considered jointly with MetS, insomnia or daytime fatigue approximately doubled the CHD risk and the presence of insufficient sleep more than tripled the risk. Among those who had MetS only, the RR was 2.55, and among those with both insufficient sleep and MetS the RR was 9.36 (95% confidence interval: 4.60-19.04; P for interaction 0.09) when compared to those with no insufficient sleep and no components of MetS.

CONCLUSION

The interaction occurred when all three measured MetS components were present, suggesting that co-occurrence of these two epidemics may predict growing public health problems.

Serum iron, infection and inflammation; effects on coronary risk

OBJECTIVES

To explore the potential pathways of association between serum iron and coronary heart disease, with major emphasis on factors related to infections and inflammation.

DESIGN

A nested case-control study with 215 cases (myocardial infarction or coronary death) and 215 matched controls over 8.5 years. Logistic regression analyses were used to compare relative risks in various serum iron-high sensitive CRP-total leucocyte count-herpes simplex virus-1 antibody categories.

RESULTS

Participants with low iron (< 17 micromol/l) had increased coronary risk with Odds Ratio (OR) of 2.1 (95% CI 1.1-3.8). Simultaneous elevation of hs-CRP and leucocyte count increased the risk substantially in those with low iron, OR 9.8 (95% CI 3.9-24.4). A combination of high herpes simplex virus-1 antibody level and low iron increased the risk modestly (OR 1.2), but when hs-CRP level was high simultaneously, the OR was 13.1 (95% CI 2.9-60.1).

CONCLUSIONS

Our data suggest an association between low serum iron level and coronary risk. The association is not independent, but is related to the fact that chronic infections and inflammation are accompanied with low serum iron.

Chlamydophila pneumonia: Specific mRNA in aorta ascendens in patients undergoing coronary artery by-pass grafting

The objective of this prospective study was to investigate if Chlamydophila pneumoniae (Cp)-specific DNA and mRNA are present in tissue samples from the wall of aorta ascendens in patients undergoing by-pass surgery for coronary artery disease (CAD) that includes stable angina pectoris (SAP, 25 patients) and acute coronary syndrome (ACS, 19 patients). Viable Cp was detected in 8/44 (18%) patients using reversed transcriptase PCR (RT-PCR) against bacterial mRNA with detection of cDNA using real-time PCR against the MOMP gene. Cp DNA was detected by nested PCR in 22/44 (50%) patients and by real-time PCR in 13/44 (30%) patients. In total, 24/44 (55%) patients were positive for Cp nucleic acid in any PCR. Antibodies to Cp were detected in 13/24 (54%) Cp PCR-positive and in 15/20 (75%) Cp PCR-negative patients. Nested PCR was run on throat swabs from all patients. No significant differences were noted between SAP and ACS patients regarding PCR results or serology. It has been suggested that Cp may be a 'silent passenger' picked up by the atherosclerotic plaque. Our findings of viable and metabolically active bacteria in aortic tissue add further support to the hypothesis that Cp may have an active role in the pathogenesis of atherosclerosis.

Genetic Loci associated with C-reactive protein levels and risk of coronary heart disease

CONTEXT

Plasma levels of C-reactive protein (CRP) are independently associated with risk of coronary heart disease, but whether CRP is causally associated with coronary heart disease or merely a marker of underlying atherosclerosis is uncertain.

OBJECTIVE

To investigate association of genetic loci with CRP levels and risk of coronary heart disease.

DESIGN, SETTING, AND PARTICIPANTS

We first carried out a genome-wide association (n = 17,967) and replication study (n = 13,615) to identify genetic loci associated with plasma CRP concentrations. Data collection took place between 1989 and 2008 and genotyping between 2003 and 2008. We carried out a mendelian randomization study of the most closely associated single-nucleotide polymorphism (SNP) in the CRP locus and published data on other CRP variants involving a total of 28,112 cases and 100,823 controls, to investigate the association of CRP variants with coronary heart disease. We compared our finding with that predicted from meta-analysis of observational studies of CRP levels and risk of coronary heart disease. For the other loci associated with CRP levels, we selected the most closely associated SNP for testing against coronary heart disease among 14,365 cases and 32,069 controls.

MAIN OUTCOME MEASURE

Risk of coronary heart disease.

RESULTS

Polymorphisms in 5 genetic loci were strongly associated with CRP levels (% difference per minor allele): SNP rs6700896 in LEPR (-14.8%; 95% confidence interval [CI], -17.6% to -12.0%; P = 6.2 x 10(-22)), rs4537545 in IL6R (-11.5%; 95% CI, -14.4% to -8.5%; P = 1.3 x 10(-12)), rs7553007 in the CRP locus (-20.7%; 95% CI, -23.4% to -17.9%; P = 1.3 x 10(-38)), rs1183910 in HNF1A (-13.8%; 95% CI, -16.6% to -10.9%; P = 1.9 x 10(-18)), and rs4420638 in APOE-CI-CII (-21.8%; 95% CI, -25.3% to -18.1%; P = 8.1 x 10(-26)). Association of SNP rs7553007 in the CRP locus with coronary heart disease gave an odds ratio (OR) of 0.98 (95% CI, 0.94 to 1.01) per 20% lower CRP level. Our mendelian randomization study of variants in the CRP locus showed no association with coronary heart disease: OR, 1.00; 95% CI, 0.97 to 1.02; per 20% lower CRP level, compared with OR, 0.94; 95% CI, 0.94 to 0.95; predicted from meta-analysis of the observational studies of CRP levels and coronary heart disease (z score, -3.45; P < .001). SNPs rs6700896 in LEPR (OR, 1.06; 95% CI, 1.02 to 1.09; per minor allele), rs4537545 in IL6R (OR, 0.94; 95% CI, 0.91 to 0.97), and rs4420638 in the APOE-CI-CII cluster (OR, 1.16; 95% CI, 1.12 to 1.21) were all associated with risk of coronary heart disease.

CONCLUSION

The lack of concordance between the effect on coronary heart disease risk of CRP genotypes and CRP levels argues against a causal association of CRP with coronary heart disease.

C-reactive protein and coronary heart disease: predictive test or therapeutic target?

BACKGROUND

The hepatocyte-derived acute-phase reactant C-reactive protein (CRP) has been the subject of intense research over the last 2 decades for its possible role in the pathogenesis of cardiovascular diseases. This research has spawned interest in the use of the blood concentration of CRP for predicting a first coronary heart disease (CHD) event, which has been made possible with the development of high-sensitivity CRP (hsCRP) assays that can measure the typically low concentrations of CRP that circulate in the absence of an overt infective or inflammatory episode, and as a potential causal factor that might be targeted therapeutically. The research has encompassed observational and genetic epidemiology, basic science studies with cells and tissues, experiments with animal models and humans, and randomized trials (although not of specific CRP-lowering therapies as yet).

CONTENT

We focus on investigations of the potential role of small differences in basal hsCRP concentration seen in healthy individuals and the relationship of such differences to the long-term risk of a first CHD event, rather than on research devoted to the high acute-phase CRP concentrations, which occur after acute atherothrombotic events and can influence the severity of ischemic tissue damage and the subsequent prognosis. We concentrate mainly on research findings at the translational interface and draw on evidence from human observational and genetic epidemiology, as well as from randomized trials.

CONCLUSIONS

As the field matures from one of discovery to an evaluative science, the development of possible clinical applications requires a sharpening of focus on and a critical appraisal of the strengths and deficiencies of the accumulated evidence. Such assessments require attention to both the current state of affairs and the design of future research, so that the existing uncertainties about the utility of CRP in predicting CHD and its role in causing this disease can be resolved.

New evidences for C-reactive protein (CRP) deposits in the arterial intima as a cardiovascular risk factor

Inflammatory processes are orchestrated by several soluble molecules, which interact with cell populations involved. Cytokines, chemokines, acute-phase reactants, and hormones are crucial in the evolution of several inflammatory disorders, such as atherosclerosis. Several evidences suggest that C-reactive protein (CRP) started to be considered as a cardiovascular risk factor, since CRP directly induces atheroslerosis development. The recent demonstration of CRP production not only by the liver, but also within atherosclerotic plaques by activated vascular cells, also suggests a possible dual role, as both a systemic and tissue agent. Although more studies are needed, some therapeutic approaches to reduce CRP levels have been performed with encouraging results. However, given the strong limitations represented by its low specificity and still accordingly with the American Heart Association, there is no need for high sensitivity CRP screening of the entire adult population as a public-health measure. The measure of serum CRP might be useful only for patients who are considered at intermediate risk.

C-reactive protein and coronary heart disease: a critical review

Modestly elevated baseline concentrations of C-reactive protein (CRP), the classical acute phase protein, are associated with the long-term risk of coronary heart disease in general populations, whilst the major acute phase response of CRP following myocardial infarction is associated with death and cardiac complications. The pathogenic and clinical significance of these associations is controversial. Here we critically review the evidence and describe large-scale epidemiological studies, novel experiments and possible specific therapies which will rigorously inform the debate. We distinguish between the potential pathogenicity of high acute phase circulating CRP concentrations in individuals with substantial tissue damage and modest but persistent increases in baseline values in generally healthy subjects.

Chemical mutagenesis: a new strategy against the global threat of infectious diseases

The perpetual evolution of drug-resistant microbes, the overwhelming burden of acquired immune suppression due to HIV, the emergence or re-emergence of various pathogens (West Nile virus, pandemic influenza, Creutzfeld-Jacob disease), and increased fears of bioterrorism has drawn a great deal of new attention to infectious diseases. The pathogenesis of infection is characterized by complex interactions of potentially virulent microorganisms with host genetic and acquired factors. Chemical mutagenesis of the mouse genome provides a robust method to unravel this challenging problem. To deepen our understanding of the natural host response to pathogens, our team and others are interrogating the mouse genome to define genes that are crucial to the defense against infectious diseases (pathogen recognition, viral defense, bacterial defense, prion infection). In this review we highlight the current progress of these efforts and propose a toolbox for other groups that are interested in this endeavor.

C-reactive protein: the harbinger of cardiovascular diseases

Coronary heart disease remains the major cause of mortality and morbidity in the United States and other western countries despite major advances in its treatment. During the last decades, many markers of coronary artery disease have been found which help predict future risk of cardiovascular events. High-sensitivity C-reactive protein has been studied extensively and was seen to be associated with a higher risk of cardiovascular events in patients with acute coronary syndromes and/or peripheral artery disease. Discussed in this review is the latest literature about this marker and its association with cardiovascular disease, as well as the latest therapeutic options available.

C-reactive protein mediates the effect of apolipoprotein E on cytomegalovirus infection

BACKGROUND

Although the apolipoprotein (APOE)-epsilon4 allele has been shown to determine the outcome of several infections, its relationship with cytomegalovirus (CMV) has not been explored. We examine whether APOE determines CMV and herpes simplex virus type 1 (HSV-1) antibody levels and assess whether C-reactive protein (CRP) mediates any observed relationships.

METHODS

We conducted a cross-sectional analysis of a randomly selected subset (n = 1561/1789) of participants aged 60-101 in the Sacramento Area Latino Study on Aging. Blood samples were tested for APOE genotype, CRP, and immunoglobulin G antibodies to CMV and HSV-1. Multivariate logistic regression was used to examine the association between epsilon4 and CMV and HSV antibody levels. We also assessed whether CRP mediates the effects of any observed associations between epsilon4 and viral antibody levels.

RESULTS

CMV antibody and CRP levels varied significantly by APOE genotype. The association between CRP and CMV antibody was strengthened in the presence of epsilon4. In contrast, this effect was not observed in HSV-1. We found that APOE-epsilon4 carriers had significantly lower levels of CRP yet significantly higher levels of CMV antibodies, suggesting a mediating pathway.

CONCLUSIONS

APOE-epsilon4 carriers may experience immunological aberrations that lead to lower levels of CRP and correspondingly higher CMV antibody levels.

Correlation of hyperhomocysteinaemia and Chlamydia pneumoniae IgG seropositivity with coronary artery disease in a general population

BACKGROUND

Both Chlamydia pneumoniae infection and hyperhomocysteinaemia have been assumed to increase the atherosclerotic risk independently of each other and independently of the classic risk factors. The correlation between hyperhomocysteinaemia, C. pneumoniae infection and coronary artery disease (CAD) have not been investigated in the general population.

METHODS

In an ancillary study to the Persian Gulf Healthy Heart Study, a cohort study of men and women aged >or=25 years, a random sample of 1699 (48.9% males, 51.1% females) subjects were evaluated. Total homocysteine, high sensitivity C-reactive protein (CRP) and IgG antibodies to C. pneumoniae were determined by ELISA. Minnesota coding criteria of a 12-lead resting electrocardiogram was used for evaluation of CAD.

RESULTS

A total of 12.4% of the subjects had electrocardiogram-defined (Minnesota-coding criteria) coronary artery disease. Hyperhomocysteinaemia (>14 micromol/l) and IgG seropositivity were found in 50.8% and 37.7%, respectively. Neither of hyperhomocysteinaemia nor C. pneumoniae IgG seropositivity showed a significant association with CAD after adjusting of sex and age. Concurrent elevated CRP level (>8.2mg/l) and C. pneumoniae seropositivity (chronic C. pneumoniae infection) had a significant association with CAD [OR=1.73, CI (1.09-2.75); p=0.01] after adjusting for age, sex, systolic and diastolic blood pressures, BMI, and serum levels of LDL-cholesterol, fasting blood sugar and triglyceride as covariates in a logistic regression model. This odds ratio increased to 2.11, CI (1.18-4.12; p=0.02) when concurrent hyperhomocysteinaemia and chronic C. pneumoniae infection, as a single covariate entity; was adjusted for multiple risk factors in another logistic regression model.

CONCLUSION

Concurrent hyperhomocysteinaemia and chronic C. pneumoniae infection, as a single entity, was independently associated with coronary artery disease in the general population. This synergism may have important implications for risk-stratification and intervention trials.

Associations between periodontal diseases and systemic diseases: a review of the inter-relationships and interactions with diabetes, respiratory diseases, cardiovascular diseases and osteoporosis

The aim of this review article is to examine the associations between periodontal diseases and common systemic diseases, namely diabetes, respiratory diseases, cardiovascular diseases and osteoporosis. A substantial number of review articles have been published to elucidate the relationships between these diseases; however, none provide a complete overview on this topic from the aspects of definition, classification, clinical characteristics and manifestations, inter-relationships and interactions, proposed schematic mechanisms, clinical implications and management of periodontal patients with these systemic diseases. The aim of this article is to provide an overall understanding and general concepts of these issues in a concise and inter-related manner.

A review of the postulated mechanisms concerning the association of Helicobacter pylori with ischemic heart disease

Since its discovery, Helicobacter pylori has been implicated in the pathogenesis of several diseases, both digestive and extradigestive. Interestingly, the majority of the extradigestive-related literature is focused on two vascular manifestations: stroke and ischemic heart disease. Potential mechanisms for the establishment of a H. pylori-induced ischemic heart disease have been proposed with regard to chronic inflammation, molecular mimicry, oxidative modifications, endothelial dysfunction, direct effect of the microorganism on atherosclerotic plaques as well as changes regarding traditional or novel risk factors for ischemic heart disease or even platelet-H. pylori interactions. A positive link between H. pylori infection and ischemic heart disease has been suggested by a series of studies focusing on epidemiologic evidence, dyslipidemic alterations, upregulation of inflammatory markers or homocysteine levels, induction of hypercoagulability, oxidation of low-density lipoprotein, causation of impaired endothelial function, detection of H. pylori DNA in atherosclerotic plaques, and participation of certain antigens and antibodies in a cross-reactivity model. There are studies, however, which investigated the relationship between H. pylori and ischemic heart disease with regard to the same parameters and failed to confirm the suggested positive association. Further studies in the direction of interaction between H. pylori and the host's genotype as well as a quest for evidence towards novel risk factors for ischemic heart disease such as oxidative stress, vascular remodeling, vascular calcification, or vasomotor activity, may reveal a field of great interest, thus contributing to the determination of new potential mechanisms.

C-Reactive Protein (CRP) as a Marker in Peripheral Vascular Disease

OBJECTIVE

To review the role of CRP as a marker for the prediction of development of Peripheral Vascular Disease (PVD) and as a prognostic indicator.

METHODS

Search of the Cochrane Vascular Group Control Trials Register, Medline and Embase for all published studies on the role of CRP as a marker in peripheral vascular disease was undertaken.13 prospective studies were found.

RESULTS

12 of the 13 prospective studies showed a strong association between CRP and PVD. Three population studies involving 16,561 people, over a period of 6.5 to 12 years, revealed that high CRP levels approximately tripled the risk of developing PVD, independently of all other risk factors. Three case-control studies found that hsCRP was much higher in patients with PVD. Four other studies, which covered 2337 people, demonstrated that CRP levels were associated inversely with lower ankle brachial pressure index. One study conducted on 384 people failed to show a link between hsCRP and progression of ABPI. Two further small studies showed that raised pre and post intervention hsCRP were associated with restenosis after angioplasty.

CONCLUSIONS

CRP appears to be a strong predictor and marker of severity of PVD and also may predict the risk of restenosis after angioplasty.

CD59 or C3 are not requred for angiotensin II-dependent hypertension or hypertrophy in mice

Complement is a major pro-inflammatory innate immune system whose serum activity correlates with systolic blood pressure in humans. To date, no studies using in vivo models have directly examined the role of individual complement components in regulating vessel function, hypertension and cardiac hypertrophy. Herein, in vivo responses to angiotensin (ang) II were characterized in mice deficient in CD59a or C3. CD59a(-/-) mice had slightly but significantly elevated systolic blood pressure (107.2 +/- 1.7 mmHg versus 113.8 +/- 1.31 mmHg, P < 0.01, for wild-type and CD59a(-/-), respectively). Aortic rings from CD59a(-/-) mice showed significantly less platelet endothelial cell adhesion molecule-1 (PECAM-1) expression, with elevated deposition of membrane attack complex. However, acetylcholine- and sodium nitroprusside-dependent dilatation, plasma nitrate/nitrite and aortic cyclic guanosine monophosphate levels were unchanged from wild-type. Also, in vivo infusion with either ang II or noradrenaline caused similar hypertension and vascular hypertrophy to wild-type. Mice deficient in C3 had similar basal blood pressure to wild type and showed no differences in hypertension or hypertrophy responses to in vivo infusion with ang II. These data indicate that CD59a deficiency is associated with some vascular alterations that may represent early damage occurring as a result of increased complement attack. However, a direct role for CD59a or C3 in modulating development of ang II-dependent hypertension or hypertrophy in vivo is excluded and we suggest caution in development of complement intervention strategies for hypertension and heart failure.

Helicobacter pylori and extragastric diseases

Since the discovery of Helicobacter pylori, several studies have investigated the hypothetical role of this bacterium in various extragastric diseases, e.g. ischemic heart disease, idiopathic thrombocytopenic purpura, iron-deficiency anaemia, and other disorders. The majority of these studies are epidemiological or eradication trials, but there are also case reports and in-vitro studies. Idiopathic thromobocytopenic purpura is the disease that shows the strongest link with H. pylori infection. There is also evidence of a role of CagA-positive H. pylori infection in iron-deficiency anaemia and ischemic heart disease. The association between H. pylori infection and other extragastric diseases remains controversial, being mostly supported by 'case reports', small pilot studies, or just in-vitro data. Further studies are needed to identify whether there is any pathological implication for H. pylori infection in these diseases.

Critical appraisal of C-reactive protein throughout the spectrum of cardiovascular disease

Clinicians involved in the care of patients with cardiovascular conditions have recently been confronted with an important body of literature linking inflammation and cardiovascular disease. Indeed, the level of systemic inflammation as measured by circulating levels of C-reactive protein (CRP) has been linked to prognosis in patients with atherosclerotic disease, congestive heart failure, atrial fibrillation, myocarditis, aortic valve disease and heart transplantation. In addition, a number of basic science reports suggest an active role for CRP in the pathophysiology of cardiovascular diseases. This article explores the potential role of CRP in disease initiation, progression, and clinical manifestations and reviews its role in the prediction of future events in clinical practice. Therapeutic interventions to decrease circulating levels of CRP are also reviewed.

Local Markers for Prediction of Women at Higher Risk of Developing Sequelae to Chlamydia trachomatis Infection

PROBLEM

Chlamydial infections are often associated with various fertility-related disorders. Serological prediction of these has limitations, as they do not differentiate between past and current infections. Thus, we looked for local markers that could predict more precisely women at higher risk of developing severe complications.

METHOD OF STUDY

A total of 320 Chlamydia trachomatis positive women with or without fertility disorders were tested for the prevalence of immunoglobulin A antibodies to synthetic peptides of chlamydial heat-shock protein 60 (cHSP60) and cHSP10 along with cervical interferon-gamma (IFN-gamma) and serum C-reactive protein (CRP) levels.

RESULTS

Positive IFN-gamma level was the single best predictor for fertility disorder [odds ratio (OR) 15.4]. The predictive value of IFN-gamma could be significantly improved only by the addition of CRP test (OR 37.9).

CONCLUSION

Positive IFN-gamma levels in cervical washes along with elevated CRP levels could be used to predict women who are at higher risk of developing fertility disorders.

Biomarkers of outcome from cardiovascular disease

PURPOSE OF REVIEW

Recognition of the fact that low-grade local and systemic inflammation accompanies all stages of atherogenesis has led to the identification of a number of novel biomarkers of cardiovascular risk. We highlight recent epidemiological and experimental evidence concerning four emerging biomarkers: C-reactive protein, interleukin-6, D-dimer and white blood cell count.

RECENT FINDINGS

Recent epidemiological and experimental data on C-reactive protein, the most extensively studied marker of systemic inflammation, produced in the liver in response to interleukin-6, has cast some doubt on its clinical utility and causal involvement in atherogenesis. However, a large number of studies still strongly support C-reactive protein as an independent predictor of future cardiovascular risk and a potent proatherogenic agent. Among all markers of inflammation studied to date, C-reactive protein seems the most suitable one for use in clinical practice. Regarding white blood cell count, recent studies focused on the differential leucocyte count in coronary-heart-disease risk assessment; neutrophil count represents the strongest predictor of incident coronary heart disease.

SUMMARY

Thus, screening for low-grade inflammation using several novel biomarkers might provide an important tool to identify individuals at increased risk who would benefit most from targeted preventive interventions.

Chlamydia pneumoniae antibody levels before coronary events in the Helsinki Heart Study as measured by different methods

The lack of specific tests for the diagnosis of chronic Chlamydia pneumoniae infection has led to the use of enzyme immunoassay (EIA) instead of the gold standard, that is, microimmunofluorescence (MIF), in the measurement of C. pneumoniae antibodies. We assessed the predictive values of C. pneumoniae antibody levels and seroconversions measured by MIF and EIA for coronary events in the prospective Helsinki Heart Study. Sera from 239 cases with coronary events and 239 controls were available at the baseline and data from 210 cases and 211 controls before and after the event. The agreement between MIF and EIA antibody levels was best in high antibody titers. In conditional logistic regression analysis, only high IgA MIF titers (>/=40) at the baseline predicted future coronary events, and the participants with MIF seroconversion between consecutive sera had a higher (nonsignificant) risk for coronary events than the controls. The difference in the kinetics of EIA and MIF antibodies demonstrated that MIF should remain the gold standard.

Serum antibody response to periodontal pathogens and herpes simplex virus in relation to classic risk factors of cardiovascular disease

BACKGROUND

Increasing evidence links chronic infections, especially burden of several infections, with increased risk for cardiovascular diseases (CVD). We studied joint immune response against two major periodontal pathogens and herpes simplex virus (HSV) in relation to established risk factors of CVD.

METHODS

Serum antibody levels to HSV, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were determined by ELISA. The study included 1107 subjects, 734 from Finland and 373 from Russia.

RESULTS

Combined antibody response to periodontal pathogens was associated inversely (OR, 95% CI) with high-density lipoprotein (HDL) cholesterol concentration (beta = 0.35; 0.20, 0.60; P < 0.001) and directly with HSV antibody quartiles: compared with the first quartile, ORs (95% CI) for quartiles 2-4 were 1.43 (0.88-2.32), 1.74 (1.07-2.82), and 1.89 (1.18-3.02), respectively (P for trend <0.001), after adjusting for age, gender, area, education, smoking, BMI, alcohol, triglycerides, and number of teeth. In linear regression analysis, the 3-pathogen antibody score (comprising antibody levels against periodontal pathogens and HSV) was inversely associated with HDL cholesterol concentration (beta = -0.067/1 mmol/l; -0.235, -0.018; P < 0.05).

CONCLUSIONS

HSV infection may promote infection by periodontal pathogens. Furthermore, the infectious burden comprising HSV and periodontitis may increase the risk for CVD by clearly decreasing HDL cholesterol concentrations.