Long-term prognostic value of neopterin: a novel marker of monocyte activation in patients with acute coronary syndrome

Plasma levels of immune system activation markers Neopterin and Kynurenine-to-Tryptophan Ratio, and oral health among community-dwelling adults in Norway: a population-based, cohort study

OBJECTIVE

Periodontitis is a condition characterised by inflammation. Neopterin and kynurenine-to-tryptophan ratio (KTR) are markers of immune system activation in response to inflammation whose elevated levels are linked to higher incidence and poorer prognosis of various systemic diseases. Their potential association with oral health remains underexplored. The aim of this study was to prospectively investigate the associations between these biomarkers and periodontal health status among community-dwelling adults in Hordaland County, Norway.

MATERIALS AND METHODS

Neopterin and KTR were measured in 1,298 participants of the Hordaland Health Study, 1997-1999. Information on oral health indicators was obtained from the 'Hordaland-Oral Health Survey', 2020-2022. Ordinal logistic regression and negative binomial regression were used to explore the association between biomarkers and periodontitis, tooth loss, and current inflammation (extend of sites with pocket depth ≥4mm and bleeding on probing) and odds ratios (OR) and incidence rate ratios (IRR), along with respective 95% confidence intervals (CI) were reported.

RESULTS

No association was found between biomarker levels and periodontitis [neopterin: OR = 0.96, 95% CI: 0.69-1.33 for fourth (Q4) vs. first quartile (Q1); KTR: OR = 0.85, 95% CI: 0.61-1.18 for Q4 vs. Q1], tooth loss [neopterin: IRR = 1.00, 95% CI: 0.94-1.06 for Q4 vs. Q1; KTR: IRR = 0.97, 95% CI: 0.91-1.03 for Q4 vs. Q1) or extend of inflammation [neopterin: OR = 0.87, 95% CI: 0.70-1.09 for Q4 vs. Q1; KTR: OR = 0.98, 95% CI: 0.78-1.23 for Q4 vs. Q1].

CONCLUSION

Plasma levels of neopterin and KTR were not prospectively associated with periodontal health and number of missing teeth.

Interferon Upregulation Associates with Insulin Resistance in Humans

In humans, insulin resistance is a physiological response to infections developed to supply sufficient energy to the activated immune system. This metabolic adaptation facilitates the immune response but usually persists after the recovery period of the infection and predisposes the hosts to type 2 diabetes and vascular injury. In patients with diabetes, superimposed insulin resistance worsens metabolic control and promotes diabetic ketoacidosis. Pathogenic mechanisms underlying insulin resistance during microbial invasions remain to be fully defined. However, interferons cause insulin resistance in healthy subjects and other population groups, and their production is increased during infections, suggesting that this group of molecules may contribute to reduced insulin sensitivity. In agreement with this notion, gene expression profiles (transcriptomes) from patients with insulin resistance show a robust overexpression of interferon- stimulated genes (interferon signature). In addition, serum levels of interferon and surrogates for interferon activity are elevated in patients with insulin resistance. Circulating levels of interferon- γ-inducible protein-10, neopterin, and apolipoprotein L1 correlate with insulin resistance manifestations, such as hypertriglyceridemia, reduced HDL-c, visceral fat, and homeostasis model assessment-insulin resistance. Furthermore, interferon downregulation improves insulin resistance. Antimalarials such as hydroxychloroquine reduce interferon production and improve insulin resistance, reducing the risk for type 2 diabetes and cardiovascular disease. In addition, diverse clinical conditions that feature interferon upregulation are associated with insulin resistance, suggesting that interferon may be a common factor promoting this adaptive response. Among these conditions are systemic lupus erythematosus, sarcoidosis, and infections with severe acute respiratory syndrome-coronavirus-2, human immunodeficiency virus, hepatitis C virus, and Mycobacterium tuberculosis.

Neopterin as a Potential Biomarker for the Early Diagnosis of Heart Failure: A Systematic Review and Meta-analysis

BACKGROUND

Neopterin (NEO) is an inflammatory biomarker with proposed diagnostic value in cardiovascular diseases. Some correlations have been discovered between NEO levels and the incidence, severity, and adverse outcomes of heart failure (HF). However, there are discrepancies in the results reported in the literature.

METHODS

We conducted a systematic review and meta-analysis of studies comparing urinary and blood NEO concentrations between individuals with HF, cardiac insufficiency, or dilated cardiomyopathy (DCM) with control groups or those monitoring the role of NEO concentrations as a predictive marker of adverse outcomes in HF patients.

RESULTS

A total of 24 studies that met the inclusion criteria were reviewed. The studies demonstrated the alteration of NEO in blood or urine samples in subjects with HF, cardiac insufficiency, or DCM compared with control groups. Also, reviewing the studies suggested a link between reduced ejection fraction, higher NYHA classes, and a higher risk of adverse cardiac outcomes with increased NEO levels. The meta-analysis of three studies revealed a significant increase in serum NEO levels in HF cases compared to that in healthy controls with an effect size of 3.72 (95 % CI 0.16 to 7.28; p = 0.04).

CONCLUSION

Meta-analysis demonstrated a significant difference between serum NEO levels of HF cases and healthy subjects. This evidence implies the potential of serum NEO as a valuable diagnostic biomarker in HF patients. Also, the review of the studies revealed the prognostic potential of NEO. Further research is required to assess the usefulness of NEO as a diagnostic/prognostic biomarker for HF.

Neopterin in patients with COPD, asthma, and ACO: association with endothelial and lung functions

BACKGROUND AND OBJECTIVE

Endothelial dysfunction has been widely recognized in chronic airway diseases, including chronic obstructive pulmonary disease (COPD) and asthma; however, it remains unclear in asthma-COPD overlap (ACO). Neopterin (NP), a metabolite of guanosine triphosphate, is a novel biomarker for identifying the increased risk of adverse cardiovascular events. This study aims to investigate the association of NP with endothelial dysfunction and impaired lung function in COPD, asthma, and ACO patients.

METHODS

A total of 77 subjects were prospectively recruited. All the participants underwent lung function test, endothelial function evaluation, including pulse wave velocity (PWV) and flow-mediated dilation (FMD), and blood sample detection. Moreover, the effect of NP on endothelial cells (ECs) in anoxic environments was assessed in vitro.

RESULTS

Endothelial function was significantly decreased in the COPD and ACO patients compared with that in the healthy controls (P < 0.05). Forced expiratory volume in 1 s (FEV1) was negatively correlated with PWV and positively correlated with FMD (P < 0.05). NP was significantly increased in patients with chronic respiratory diseases compared with that in the control group, with COPD being the highest, followed by asthma, and ACO as the last (P < 0.05). The plasma level of NP exhibited negative correlations with FEV1 and positive correlations with PWV (P < 0.05). In vitro, a high level of NP increased the reactive oxygen species (ROS) and decreased the mitochondrial membrane potential (ΔΨm) of ECs dose-dependently in a hypoxic environment (P < 0.05).

CONCLUSION

NP was related to disease severity of chronic airway diseases and involved in the pathogenesis of endothelial dysfunction. A high NP level may contribute to endothelial dysfunction by increasing the oxidative stress of ECs dose-dependently in a hypoxic environment. Our findings may provide a novel evaluation and therapeutic target for endothelial dysfunction related to chronic airway diseases.

Evaluation of neopterin levels and kynurenine pathway in patients with acute coronary syndrome

BACKGROUND

Coronary atherosclerosis is the leading cause of coronary artery disease. Several investigations have indicated that tear-sensitive plaques contain macrophages and T cells. Neopterin is an essential cellular immune response biomarker. The main goal of this study was to see if there were any changes in biomarkers like unconjugated pteridines, neopterin, and biopterin, as well as kynurenine pathway enzymes like indoleamine 2,3-dioxygenase (IDO), which catalyzes the rate-limiting step in tryptophan degradation, in patients with the acute coronary syndrome (ACS) caused by angiographic atherosclerosis.

METHODS

High-performance liquid chromatography was used to determine the amounts of neopterin, biopterin, and creatinine in urine samples, as well as tryptophan and kynurenine in serum samples. The enzyme-linked immunosorbent assay was used to assess the amounts of neopterin in serum samples. The measured parameters were evaluated between ACS patients and controls.

RESULTS

The measured levels of neopterin, biopterin and the kynurenine to tryptophan ratio reflecting IDO activity, and the specifically known biomarkers such as cardiac troponin, creatine kinase, myoglobin, and natriuretic peptides are statistically higher in ACS patients compared to control subjects. On the other hand, the measured parameters are inadequate to classify the conventional kinds of ACS, ST-elevation- and non-ST-elevation- myocardial infarction.

CONCLUSIONS

The study found that determining and using neopterin and IDO parameters as biomarkers in individuals with the ACS can support traditional biomarkers. However, it can be concluded that evaluating pteridine biomarkers solely have no privilege to clinical findings in ACS diagnosis and classification.

Tryptophan was metabolized into beneficial metabolites against coronary heart disease or prevented from producing harmful metabolites by the in vitro drug screening model based on Clostridium sporogenes

In our previous study of 2,130 Chinese patients with coronary heart disease (CHD), we found that tryptophan (TRP) metabolites contributed to elevated risks of death. Many TRP-derived metabolites require the participation of intestinal bacteria to produce, and they play an important role in the pathogenesis of metabolic diseases such as CHD. So it is necessary to metabolize TRP into beneficial metabolites against CHD or prevent the production of harmful metabolites through external intervention. Indole-3-butyric acid (IBA) may be a key point of gut microbiota that causes TRP metabolism disorder and affects major adverse cardiovascular events in CHD. Therefore, this study aimed to develop a method based on in vitro culture bacteria to evaluate the effects of IBA on specific microbial metabolites quickly. We detected the concentrations of TRP and its metabolites in 11 bacterial strains isolated from feces using liquid chromatography–mass spectrometry, and selected Clostridium sporogenes as the model strain. Then, IBA was used in our model to explore its effect on TRP metabolism. Results demonstrated that the optimal culture conditions of C. sporogenes were as follows: initial pH, 6.8; culture temperature, 37°C; and inoculum amount, 2%. Furthermore, we found that IBA increases the production of TRP and 5-HIAA by intervening TRP metabolism, and inhibits the production of KYNA. This new bacteria-specific in vitro model provides a flexible, reproducible, and cost-effective tool for identifying harmful agents that can decrease the levels of beneficial TRP metabolites. It will be helpful for researchers when developing innovative strategies for studying gut microbiota.

Clinical comparative study assessing the effect of ivabradine on neopterin and NT-Pro BNP against standard treatment in chronic heart failure patients

Purpose

Heart rate reduction (HR) is a cornerstone in heart failure therapy as it improves patient outcomes. The aim of this study is to evaluate short-term effect of ivabradine on NT-Pro BNP and neopterin in heart failure patients and assess the association between HR and these biomarkers.

Methods

Sixty patients on standard heart failure therapy were randomly allocated into ivabradine group (n = 30) and non-ivabradine group (n = 30). Ivabradine 5 mg twice daily was given for 3 months. Lipid profile and kidney functions were performed and blood samples for NT-Pro BNP and neopterin were analysed at baseline and after 3 months of intervention in both groups.

Results

There was a significant improvement in NYHA class in ivabradine group (p < 0.001). Ejection fraction was improved in ivabradine and non-ivabradine groups after intervention (p < 0.001), with a greater improvement in ivabradine group (p = 0.026). Heart rate was reduced in ivabradine group (p < 0.001) and non-ivabradine group (p < 0.001) yet greater reduction was seen in ivabradine group (p < 0.001). Serum creatinine and blood urea nitrogen were reduced in ivabradine group (Scr: p = 0.001, BUN: p = 0.001). NT-Pro BNP and neopterin levels significantly decreased in ivabradine group (NT-Pro BNP: p < 0.001, neopterin p < 0.001). Significant positive correlation was found between HR and biomarker levels after intervention (NT-Pro BNP: r = 0.475, p < 0.001, neopterin: r = 0.384, p = 0.002).

Conclusion

Ivabradine therapy reduced levels of both biomarkers which correlated well with HR. Biomarker levels might provide a tool for assessing ivabradine effectiveness in HF.

Trial registration

Date: June 26, 2020. Identifier: NCT04448899. Link: Ivabradine in Patients with Congestive Heart Failure—Full Text View—ClinicalTrials.gov.

The presence of Neopterin in the sera of a sample of Iraqi acromegalic patients (Type 2 diabetics and nondiabetics)

Back ground: Acromegaly is a rare endocrine disease; its incidence is 4-6 million per year, while its prevalence is 40-60 million per year. They are separating acromegaly from gigantism that occurs before growth plates are closed. Neopterin is a systemic adaptive immune activation biomarker produced upon interferon-gamma (IFN-γ) stimulation by monocyte-derived macrophages and dendritic cells. Eighty acromegalic patients (50% diabetic acromegalic and 50% nondiabetic acromegalic) and forty healthy control groups were enrolled in the study to find out the level of Neopterin and insulin-like growth factor-1 in the sera of the study population; the results showed both molecules (neopterin and Insulin-like growth factor-1 were found to be high in acromegalic subjects when there is concomitant diabetes, and insulin-like growth factor-1 correlates positively with total cholesterol and neopterin. At the same time, neopterin correlates positively with HbA1c. This study was aimed to find out the difference in neopterin level in diabetic acromegalic versus n0n-diabetic acromegalic patients; Eighty acromegalic subjects were enrolled in across sectional study by measuring the neopterin level in the sera of diabetics and nondiabetics as 39 have diabetes while the remaining 41 patients are nondiabetic. Neopterin is high among diabetic acromegalic patients when compared with nondiabetic acromegalic subjects. Insulin-like growth factor-1 correlates positively with neopterin and total cholesterol; (4) Conclusions: Across sectional-study enrolling eighty acromegalic patients registered in the National Diabetes Center. Thus they were subdivided into two groups: - diabetic and nondiabetic the level of neopterin was found to be among diabetic versus nondiabetics.

Circulating Blood-Based Biomarkers in Pulmonary Hypertension

Pulmonary hypertension (PH) is a serious hemodynamic condition, characterized by increased pulmonary vascular resistance (PVR), leading to right heart failure (HF) and death when not properly treated. The prognosis of PH depends on etiology, hemodynamic and biochemical parameters, as well as on response to specific treatment. Biomarkers appear to be useful noninvasive tools, providing information about the disease severity, treatment response, and prognosis. However, given the complexity of PH, it is impossible for a single biomarker to be adequate for the broad assessment of patients with different types of PH. The search for novel emerging biomarkers is still ongoing, resulting in a few potential biomarkers mirroring numerous pathophysiological courses. In this review, markers related to HF, myocardial remodeling, inflammation, hypoxia and tissue damage, and endothelial and pulmonary smooth muscle cell dysfunction are discussed in terms of diagnosis and prognosis. Extracellular vesicles and other markers with complex backgrounds are also reviewed. In conclusion, although many promising biomarkers have been identified and studied in recent years, there are still insufficient data on the application of multimarker strategies for monitoring and risk stratification in PH patients.

Determination of Neopterin as a Prognostic Indicator Using Neopterin-Imprinted Cryogel Membranes

Neopterin (Neo) is thought of as a key biomarker for the diagnosis and prognosis of a wide variety of diseases associated with cellular immune response. Therefore, it has become a vital need to be able to specifically determine the Neo concentration in human serum. Molecularly imprinted cryogels have come into prominence among other affinity systems by combining advantages of Molecular Imprinting Technology (MIT) and cryogels. In this chapter, synthesis of novel Neopterin-imprinted cryogel membranes (Neo-mip), characterization studies of synthesized materials, and their use in the determination of Neo in human serum is described in detail. In addition, the evaluation of selective Neo adsorption properties of Neo-mip against competitors (Pterin and Glucose) is discussed. Neo-mip will come into prominence as important affinity materials for the selective Neo recognition in body fluids, prior to use in the health sector.

Lipophilic vs. hydrophilic statins and psychiatric hospitalizations and emergency room visits in US Veterans with schizophrenia and bipolar disorder

Objective –

Psychiatric hospitalizations and emergency department (ED) visits are costly, stigmatizing, and often ineffective. Given the immune and kynurenine activation in bipolar disorder (BD) and schizophrenia, as well as the immune-modulatory effects of statins, we aimed to compare the relative risk (RRs) of psychiatric hospitalizations and ED visits between individuals prescribed lipophilic vs. hydrophilic statins vs. no statins. We hypothesized (a) reduced rates of hospitalization and ER utilization with statins versus no statins and (b) differences in outcomes between statins, as lipophilia increases the capability to penetrate the blood–brain barrier with potentially beneficial neuroimmune, antioxidant, neuroprotective, neurotrophic, and endothelial stabilizing effects, and, in contrast, potentially detrimental decreases in brain cholesterol concentrations leading to serotoninergic dysfunction, changes in membrane lipid composition, thus affecting ion channels and receptors.

Methods –

We used VA service utilization data from October 1, 2010 to September 30, 2015. The RRs for psychiatric hospitalization and ED visits, were estimated using robust Poisson regression analyses. The number of individuals analyzed was 683,129.

Results –

Individuals with schizophrenia and BD who received prescriptions for either lipophilic or hydrophilic statins had a lower RR of psychiatric hospitalization or ED visits relative to nonstatin controls. Hydrophilic statins were significantly associated with lower RRs of psychiatric hospitalization but not of ED visits, compared to lipophilic statins.

Conclusion –

The reduction in psychiatric hospitalizations in statin users (vs. nonusers) should be interpreted cautiously, as it carries a high risk of confounding by indication. While the lower RR of psychiatric hospitalizations in hydrophilic statins relative to the lipophilic statins is relatively bias free, the finding bears replication in a specifically designed study. If replicated, important clinical implications for personalizing statin treatment in patients with mental illness, investigating add-on statins for improved therapeutic control, and mechanistic exploration for identifying new treatment targets are natural next steps.

Serum neopterin levels and their role in the prognosis of patients with ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Neopterin is an inflammatory marker that is found to have prognostic value in cardiovascular diseases but its prognostic role in cerebrovascular diseases is not as clear. This study evaluates the prognostic role of neopterin in patients with ischemic stroke.

METHOD

Studies were identified after a literature search in electronic databases (Ovid, PubMed, Science Direct, and Wiley) and were selected based on precise eligibility criteria. Random-effects meta-analyses were performed to estimate mean difference in blood neopterin levels between ischemic stroke patients and healthy individuals or between severe and low/moderate ischemic stroke. Prognostic information contained in research articles of included studies was synthesized.

RESULTS

Fourteen studies (1823 ischemic stroke patients and 2189 healthy individuals) were included. Serum neopterin levels were 4.22 ng/ml [95% confidence interval (CI): 3.66, 4.77] in ischemic stroke patients and 1.80 ng/ml [95% CI: 1.13, 2.46] in normal individuals (mean difference 2.14 ng/ml [95% CI: 1.41, 2.87]; p < 0.00001). Neopterin levels were significantly higher in patients with severe than in low/moderate ischemic stroke (mean difference 1.36 ng/ml [95% CI: 0.58, 2.13]; p = 0.0006). In individual studies, higher serum neopterin levels were found to be predictive of secondary stroke, adverse clinical or functional outcomes, depression, and mortality. Neopterin levels correlated positively with high-sensitivity c reactive protein (hsCRP), National Institutes of Health Stroke Scale score, and infarct volume.

CONCLUSION

Blood neopterin levels are found significantly higher in ischemic stroke patients and correlated positively with hsCRP, disease severity, and infarct volume. Higher neopterin levels are associated with a worse prognosis of ischemic stroke.

Inflammatory markers and risk of cardiovascular mortality in relation to diabetes status in the HUNT study

Inflammatory markers have been associated with increased risk of cardiovascular mortality in general populations. We assessed whether these associations differ by diabetes status. From a population-based cohort study (n = 62,237) we included all participants with diabetes (n = 1753) and a control group without diabetes (n = 1818). Cox regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for possible associations with cardiovascular mortality of 4 different inflammatory markers; C-reactive protein (CRP), calprotectin, neopterin and lactoferrin. During a median follow-up of 13.9 years, 728 (20.4%) died from cardiovascular disease (CVD). After adjustment for age, sex and diabetes, the associations of all inflammatory markers with risk of cardiovascular mortality were log-linear (all P ≤ 0.017 for trend) and did not differ according to diabetes status (all P ≥ 0.53 for interaction). After further adjustments for established risk factors, only CRP remained independently associated with cardiovascular mortality. HRs were 1.22 (1.12-1.32) per standard deviation higher loge CRP concentration and 1.91 (1.50-2.43) when comparing individuals in the top versus bottom quartile. The associations of CRP, calprotectin, lactoferrin and neopterin with cardiovascular mortality did not differ by diabetes, suggesting that any potential prognostic value of these markers is independent of diabetes status.

Oxidative Stress and Low-Grade Inflammation in Polycystic Ovary Syndrome: Controversies and New Insights

The pathophysiology of Polycystic Ovary Syndrome (PCOS) is quite complex and different mechanisms could contribute to hyperandrogenism and anovulation, which are the main features of the syndrome. Obesity and insulin-resistance are claimed as the principal factors contributing to the clinical presentation; in normal weight PCOS either, increased visceral adipose tissue has been described. However, their role is still debated, as debated are the biochemical markers linked to obesity per se. Oxidative stress (OS) and low-grade inflammation (LGI) have recently been a matter of researcher attention; they can influence each other in a reciprocal vicious cycle. In this review, we summarize the main mechanism of radical generation and the link with LGI. Furthermore, we discuss papers in favor or against the role of obesity as the first pathogenetic factor, and show how OS itself, on the contrary, can induce obesity and insulin resistance; in particular, the role of GH-IGF-1 axis is highlighted. Finally, the possible consequences on vitamin D synthesis and activation on the immune system are briefly discussed. This review intends to underline the key role of oxidative stress and low-grade inflammation in the physiopathology of PCOS, they can cause or worsen obesity, insulin-resistance, vitamin D deficiency, and immune dyscrasia, suggesting an inverse interaction to what is usually considered.

Relationship Between Serum Neopterin Level and Peripheral Arterial Plaque in Patients with Type 2 Diabetes

OBJECTIVE

Neopterin is an inflammatory factor synthesized by monocyte macrophages in response to γ-interferon. It plays an important role in regulating a variety of physiological and pathological processes, including obesity, diabetes, and cardiovascular disease. This study aims to clarify the relationship between peripheral arterial plaque and serum neopterin in type 2 diabetes.

METHODS

We consecutively selected 121 inpatients with type 2 diabetes. After collecting relevant clinical indicators, we collected serum from all patients and measured neopterin levels through enzyme linked immune sorbent assay. Peripheral arterial plaques (the carotid and femoral arteries) were detected by B-mode ultrasound. Multivariate logistic regression was used to determine the independent influencing factors. The correlation between neopterin levels and other variables was analyzed by Spearman correlation analysis. P <0.05 was considered to be statistically significant.

RESULTS

There was no difference in serum neopterin levels between arterial plaques group and no plaques group. Serum neopterin levels in patients with carotid plaque were elevated compared to patients without carotid plaque. Logistic regression analysis showed that a higher serum neopterin level was an independent risk factor for the presence of carotid plaques. Serum neopterin levels were positively correlated with BMI, HOMA-IR, and serum creatinine and negatively correlated with eGFR.

CONCLUSION

Serum neopterin levels were positively and independently associated with carotid plaque in patients with type 2 diabetes.

Neopterin formation through radical scavenging of superoxide by the macrophage synthesised antioxidant 7,8-dihydroneopterin

Clinical measurement of neopterin has been extensively used as a marker of inflammation but the in vivo mechanism generating neopterin is poorly understood. Neopterin is described as the oxidation product of 7,8-dihydroneopterin, a potent antioxidant generated by monocyte/macrophages in response to interferon-γ. While peroxyl and hydroxyl scavenging generates dihydroxanthopterin, hypochlorite efficiently oxidises 7,8-dihydroneopterin into neopterin, but this reaction alone does not explain the high levels of neopterin seen in clinical data. Here, we examine whether superoxide scavenging by 7,8-dihydroneopterin generates neopterin. U937 cells incubated with oxLDL showed a time dependent increase superoxide and 7,8-dihydroneopterin oxidation to neopterin. Neopterin generation in oxLDL or phorbol ester treated U937 cells or human monocytes was inhibited by apocynin and PEG-SOD. Addition of the myeloperoxidase inhibitor 4-aminobenzoic acid hydrazide (ABAH) had no effect of the superoxide generation or neopterin formation. 7,8-Dihydroneopterin reacted with superoxide/hydroxy radical mixtures generated by X-ray radiolysis to give neopterin. Formation of neopterin by superoxide derived from the xanthine/xanthine oxidase system was inhibited by superoxide dismutase. Neopterin formation was inhibited by apocynin in phorbol ester treated human carotid plaque rings in tissue culture. These results indicate that 7,8-dihydroneopterin scavenges superoxide and is subsequently oxidised into neopterin in cellular and cell-free experimental systems.

Neopterin is Associated with Disease Severity and Outcome in Patients with Non-Ischaemic Heart Failure

Inflammation and immune activation play an important role in the pathogenesis of cardiac remodelling in patients with heart failure. The aim of this study was to assess whether biomarkers of inflammation and immune activation are linked to disease severity and the prognosis of heart failure patients. In 149 patients (65.8% men, median age 49.7 years) with heart failure from nonischaemic cardiomyopathy, the biomarkers neopterin and C-reactive protein were tested at the time of diagnosis. Patients were followed-up for a median of 58 months. During follow-up, nineteen patients died, five had a heart transplantation, two needed a ventricular assistance device, and twenty-one patients had to be hospitalised because of heart failure decompensation. Neopterin concentrations correlated with N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations (rs = 0.399, p < 0.001) and rose with higher New York Heart Association (NYHA) class (I: 5.60 nmol/L, II: 6.90 nmol/L, III/IV: 7.80 nmol/L, p = 0.033). Higher neopterin levels were predictive for an adverse outcome (death or hospitalisation due to HF decompensation), independently of age and sex and of established predictors in heart failure such as NYHA class, NT-proBNP, estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction (LV-EF) (HR 2.770; 95% CI 1.419-5.407; p = 0.003). Patients with a neopterin/eGFR ratio ≥ 0.133 (as a combined marker for immune activation and kidney function) had a more than eightfold increased risk of reaching an endpoint compared to patients with a neopterin/eGFR ratio ≤0.065 (HR 8.380; 95% CI 2.889-24.308; p < 0.001). Neopterin is associated with disease severity and is an independent predictor of prognosis in patients with heart failure.

Neopterin as a novel marker; well correlated with mortality and morbidity in patients with advanced systolic heart failure

Objective: The aim of this study is research relation of serum neopterin level with mortality and morbidity due to systolic HF and also its role in diagnosis of patients with systolic HF. Material and methods: Eighty-one patients with systolic heart failure (HF group) and eighty-one age- and gender-matched healthy subjects (the control group) were enrolled in the study. Echocardiographic examination was performed accordingly. At the beginning of the study, serum B type natriuretic peptide (BNP), neopterin, and high sensitive C-reactive protein (hs-CRP) were measured accordingly. The subjects were followed for one year then after. Mortality rate and number of hospitalisation due to HF were recorded. Results: Age and gender distribution over the groups were statistically similar (p > .05). LVEF of the control and HF groups were 62 ± 3 and 27 ± 3%, respectively (p < .001). Average neopterin value of HF group was significantly higher than that of the control group (p < .001). Both hs-CRP and BNP values were well correlated to neopterin values (p = .667 and .778, respectively). There was a significant correlation between number of hospitalisation and neopterin values among patients in HF group (p = .008). Also among HF group, neopterin value of patients died within first year of follow-up (n = 29) was higher than that of patients survived beyond first year (n = 52 and p = .011). Conclusions: Neopterin is a biomarker reflecting ongoing inflammatory process in deteriorating heart. High level of serum neopterin concentrations was associated with mortality and morbidity in systolic HF.

Elevated serum neopterin and homocysteine increased the risk of ischemic stroke in patients with transient ischemic attack

Objective: To investigate the correlation between serum neopterin, homocysteine (Hcy) and the risk of developing ischemic stroke (IS) in patients with transient ischemic attack (TIA).

Methods: Ninety-two TIA patients were prospectively recruited at the First Affiliated Hospital of the Medical College, Shihezi University, Xinjiang Autonomous Region China. Of the included patients, 27 developed ischemic stroke (IS group) and other 65 cases did not (TIA group). Peripheral venous blood was obtained within 24 hours of TIA diagnosis. Serum neopterin, Hcy and serum lipid levels were tested and compared between IS and TIA groups.

Results: Serum neopterin (6.38±1.76 ng/mL vs 5.39±1.51 ng/mL), Hcy (17.95±4.10 μmol/L vs 15.30±3.66 μmol/L), TG (1.82±0.92 mmol/L vs 1.40±0.71 mmol/L) and LDL (3.31±0.67 mmol/L vs 2.69±0.62 mmol/L) of IS group were significantly higher than those of TIA group (p<0.05). The AUC of serum neopterin, Hcy, TG and LDL for predicting the risk of developing IS in patients with TIA were 0.68 (95%CI: 0.55-0.81, 0.68 (95%CI: 0.57-0.80), 0.64 (95%CI: 0.51-0.78) and 0.75 (95%CI: 0.63-0.86), respectively.

Conclusion: Serum neopterin, Hcy, TG and LDL are promising serological markers for predicting the increased risk of developing IS for patients with TIA.

Neopterin and Cardiovascular Events Following Coronary Stent Implantation in Patients with Stable Angina Pectoris

AIM

Neopterin is an activation marker for monocytes/macrophages. We prospectively investigated the predictive value of plasma neopterin levels on 2-year and long-term cardiovascular events in patients with stable angina pectoris (SAP) undergoing coronary stent implantation.

METHODS

We studied 123 consecutive patients with SAP who underwent primary coronary stenting (44 patients with bare metal stent: BMS group and 79 with drug-eluting stent: DES group). Plasma neopterin levels were measured on admission using HPLC. Moreover, one frozen coronary artery specimen after DES and three frozen coronary specimens after BMS were obtained by autopsy or endarterectomy, followed by immunohistochemical staining for neopterin.

RESULTS

Plasma neopterin levels were significantly higher in patients with cardiovascular events than in those without them (P＜0.001). In subgroup analyses, higher levels of plasma neopterin in patients with cardiovascular events (P＜0.001) and a positive correlation between neopterin levels and late lumen loss after stenting (P =0.008) were observed in the BMS group but not in the DES group (P=0.53 and P=0.17, respectively). In long-term cardiovascular events, multivariate Cox regression analysis identified the significance of the high-neopterin group as independent determinants of cardiovascular events (hazard ratio, 2.225; 95% CI, 1.283-3.857; P =0.004). Immunohistochemical staining showed abundant neopterin-positive macrophages in the neointima after BMS implantation but no neopterin-positive macrophages in the neointima after DES implantation.

CONCLUSION

These findings suggest that neopterin is associated with cardiovascular events after coronary stent implantation in patients with SAP. However, there might be a strong association between neopterin and cardiovascular events after BMS but not after DES in these patients.

Plasma levels of soluble VEGF receptor isoforms, circulating pterins and VEGF system SNPs as prognostic biomarkers in patients with acute coronary syndromes

Background

Development of collateral circulation in coronary artery disease is cardio-protective. A key process in forming new blood vessels is attraction to occluded arteries of monocytes with their subsequent activation as macrophages. In patients from a prospectively recruited post-acute coronary syndromes cohort we investigated the prognostic performance of three products of activated macrophages, soluble vascular endothelial growth factor (VEGF) receptors (sFlt-1 and sKDR) and pterins, alongside genetic variants in VEGF receptor genes, VEGFR-1 and VEGFR-2.

Methods

Baseline levels of sFlt-1 (VEGFR1), sKDR (VEGFR2) and pterins were measured in plasma samples from subgroups (n = 513; 211; 144, respectively) of the Coronary Disease Cohort Study (CDCS, n = 2067). DNA samples from the cohort were genotyped for polymorphisms from the VEGFR-1 gene SNPs (rs748252 n = 2027, rs9513070 n = 2048) and VEGFR-2 gene SNPs (rs2071559 n = 2050, rs2305948 n = 2066, rs1870377 n = 2042).

Results

At baseline, levels of sFlt-1 were significantly correlated with age, alcohol consumption, NTproBNP, BNP and other covariates relevant to cardiovascular pathophysiology. Total neopterin levels were associated with alcohol consumption at baseline. 7,8 dihydroneopterin was associated with BMI. The A allele of VEGFR-2 variant rs1870377 was associated with higher plasma sFlt-1 and lower levels of sKDR at baseline. Baseline plasma sFlt-1 was univariately associated with all cause mortality with (p < 0.001) and in a Cox’s proportional hazards regression model sFlt-1 and pterins were both associated with mortality independent of established predictors (p < 0.027).

Conclusions

sFlt-1 and pterins may have potential as prognostic biomarkers in acute coronary syndromes patients. Genetic markers from VEGF system genes warrant further investigation as markers of levels of VEGF system components in these patients.

Trial registration

Australian New Zealand Clinical Trials Registry. ACTRN12605000431628. 16 September 2005, Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0894-1) contains supplementary material, which is available to authorized users.

T cell and monocyte/macrophage activation markers associate with adverse outcome, but give limited prognostic value in anemic patients with heart failure: results from RED-HF

BACKGROUND

Activated leukocytes may contribute to the development and progression of heart failure (HF). We investigated the predictive value of circulating levels of stable and readily detectable markers reflecting both monocyte/macrophage and T-cell activity, on clinical outcomes in HF patients with reduced ejection fraction (HFrEF).

METHODS

The association between baseline plasma levels of soluble CD163 (sCD163), macrophage migration inhibitory factor (MIF), granulysin, soluble interleukin-2 receptor (sIL-2R), and activated leukocyte cell adhesion molecule (ALCAM) and the primary endpoint of death from any cause or first hospitalization for worsening of HF was evaluated using multivariable Cox proportional hazard models in 1541 patients with systolic HF and mild to moderate anemia, enrolled in the Reduction of Events by darbepoetin alfa in Heart Failure (RED-HF) trial. Modifying effects and interaction with darbepoetin alfa treatment were also assessed.

RESULTS

All leukocyte markers, except granulysin, were associated with the primary outcome and all-cause death in univariate analysis (all p < 0.01) and remained significantly associated in multivariable analysis adjusting for conventional clinical variables (e.g. age, gender, BMI, NYHA class, creatinine, LVEF, etiology) and CRP. However, after final adjustment for TnT and NT-proBNP no associations were found with outcomes. No interaction with darbepoetin alpha treatment was observed for any marker.

CONCLUSIONS

Leukocyte activation markers sCD163, MIF, sIL-2R, and ALCAM were associated with adverse outcome in patients with HFrEF, but add little as prognostic markers on top of established biochemical risk markers.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT00358215 .

Systemic Inflammatory Response and Atherosclerosis: The Paradigm of Chronic Inflammatory Rheumatic Diseases

Patients with Chronic Inflammatory Rheumatic diseases (CIRD) are at increased risk of cardiovascular disease (CVD), ascribed not only to classical risk factors, but also to the presence of chronic systemic inflammatory response. Αtherosclerosis, the cornerstone of CVD, is known to be accelerated in CIRD; rheumatoid arthritis promotes atheromatosis and associates with preclinical atherosclerosis equivalent to Diabetes Mellitus, which also seems to apply for systemic lupus erythematosus. Data on ankylosing spondylitis and psoriatic arthritis, albeit more limited, also support an increased CV risk in these patients. The association between inflammation and atherosclerosis, has been thoroughly investigated in the last three decades and the role of inflammation in the pathogenesis and progression of atherogenesis has been well established. Endothelial dysfunction, oxidative stress in vascular endothelial cells and macrophage accumulation, toll-like receptor signaling, NLPR-3 formation and subsequent pro-inflammatory cytokine production, such as TNFa, IL-1β, IL-6, and TNF-like cytokine 1A, are few of the mechanisms implicated in the atherogenic process. Moreover, there is evidence that anti-inflammatory biologic drugs, such as anti-TNF and anti-IL1β agents, can decelerate the atherogenic process, thus setting new therapeutic targets for early and effective disease control and suppression of inflammation, in addition to aggressive management of classical CV risk factors.

Neopterin as a Biomarker in Patients with Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Upregulation of the immune system is regarded to play an important role in the etiopathobiology of pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH). To the best of our knowledge, neopterin (NP) has never been investigated in patients with PAH and CTEPH.

OBJECTIVES

The aim of the study was to evaluate the concentration of NP in blood in order to examine its impact on outcome and relationship with disease severity in that population.

METHODS

Serum concentration of NP was analysed prospectively in 50 patients (36 with PAH and 14 with CTEPH vs. 31 healthy controls) and assessed in relation to clinical parameters and outcome.

RESULTS

NP concentration in the PAH and CTEPH groups combined was significantly higher than in the control group (8.68, 6.39-15.03 vs. 5.14, 4.16-5.98 nmol/L, p < 0.0000001). During 9 months of follow-up, clinical deterioration occurred in 18 patients (including 8 deaths), and NP concentration in this group was higher when compared to stable patients (15.6, 8.52-25.13 vs. 7.87, 6.18-9.89, p = 0.002). The cutoff value of NP derived from ROC curve analysis was 15.3 nmol/L (p = 0.002, AUC 0.77, p = 0.0004, HR = 4.35, 95% CI 1.43-13.18, log-rank test). On Cox regression analysis, NP predicted clinical deterioration (p = 0.009, 95% CI 1.01-1.06). NP correlated positively with NT-proBNP (p < 0.001), red blood cell distribution width (p < 0.001), and right atrium area (p = 0.002) and inversely with 6-min walking test (p = 0.002) and peak oxygen consumption (p = 0.001).

CONCLUSIONS

NP concentration is increased in patients with PAH and inoperable CTEPH. Elevated NP concentration is associated with adverse clinical outcomes and correlates with clinical parameters.

The role of the kynurenine pathway of tryptophan metabolism in cardiovascular disease

Coronary heart disease and stroke, the deadliest forms of cardiovascular disease (CVD), are mainly caused by atherosclerosis, a chronic inflammatory disease of the artery wall driven by maladaptive immune responses in the vessel wall. Various risk factors for CVD influence this pathogenic process, including diabetes mellitus, hypertension, dyslipidaemia, and obesity. Indoleamine 2,3-dioxygenase (IDO), an enzyme catalyzing the rate-limiting step in the kynurenine pathway of tryptophan degradation, is strongly induced by inflammation in several tissues, including the artery wall. An increasing body of evidence indicates that IDO promotes immune tolerance, decreases inflammation, and functions as a homeostatic mechanism against excessive immune reactions.

This review provides an overview of the emerging field of the kynurenine pathway of tryptophan degradation in CVD, emphasizing the role of IDO-mediated tryptophan metabolism and its metabolites in the modulation of ‘classical’ cardiovascular risk factors, such as hypertension, obesity, lipid metabolism, diabetes mellitus, and in the development of atherosclerotic CVD.

Association of Osteopontin, Neopterin, and Myeloperoxidase With Stroke Risk in Patients With Prior Stroke or Transient Ischemic Attacks: Results of an Analysis of 13 Biomarkers From the Stroke Prevention by Aggressive Reduction in Cholesterol Levels Trial

BACKGROUND AND PURPOSE

Established risk factors do not fully identify patients at risk for recurrent stroke. The SPARCL trial (Stroke Prevention by Aggressive Reduction in Cholesterol Levels) evaluated the effect of atorvastatin on stroke risk in patients with a recent stroke or transient ischemic attack and no known coronary heart disease. This analysis explored the relationships between 13 plasma biomarkers assessed at trial enrollment and the occurrence of outcome strokes.

METHODS

We conducted a case-cohort study of 2176 participants; 562 had outcome strokes and 1614 were selected randomly from those without outcome strokes. Time to stroke was evaluated by Cox proportional hazards models.

RESULTS

There was no association between time to stroke and lipoprotein-associated phospholipase A₂, monocyte chemoattractant protein-1, resistin, matrix metalloproteinase-9, N-terminal fragment of pro-B-type natriuretic peptide, soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, or soluble CD40 ligand. In adjusted analyses, osteopontin (hazard ratio per SD change, 1.362; P<0.0001), neopterin (hazard ratio, 1.137; P=0.0107), myeloperoxidase (hazard ratio, 1.177; P=0.0022), and adiponectin (hazard ratio, 1.207; P=0.0013) were independently associated with outcome strokes. After adjustment for the Stroke Prognostic Instrument-II and treatment, osteopontin, neopterin, and myeloperoxidase remained independently associated with outcome strokes. The addition of these 3 biomarkers to Stroke Prognostic Instrument-II increased the area under the receiver operating characteristic curve by 0.023 (P=0.015) and yielded a continuous net reclassification improvement (29.1%; P<0.0001) and an integrated discrimination improvement (42.3%; P<0.0001).

CONCLUSIONS

Osteopontin, neopterin, and myeloperoxidase were independently associated with the risk of recurrent stroke and improved risk classification when added to a clinical risk algorithm.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00147602.

Neopterin as an Effect Modifier of the Cardiovascular Risk Predicted by Total Homocysteine: A Prospective 2-Cohort Study

BACKGROUND

Plasma total homocysteine (tHcy) is related to plasma neopterin, an indicator of interferon-γ-mediated immune activation, and both biomarkers positively predict cardiovascular risk. We examined whether the association between tHcy and subsequent risk of acute myocardial infarction (AMI) was modified by systemic concentrations of neopterin and C-reactive protein among patients with coronary heart disease.

METHODS AND RESULTS

By Cox modeling, we explored the association between tHcy and risk of AMI in 4164 patients with suspected stable angina pectoris. Subgroup analyses were performed according to median levels of neopterin and C-reactive protein. A replication study was performed among 3749 patients with AMI at baseline. Median follow-up was 7.3 and 8.3 years among patients with stable angina pectoris and AMI, respectively. tHcy and neopterin correlated in both cohorts (rs=0.34 and rs=0.30 among stable angina pectoris and AMI patients, respectively, both P<0.001). tHcy predicted AMI in both cohorts, independent of B-vitamin treatment. However, significant risk associations were confined to patients with plasma neopterin above the median (hazard ratios [95% confidence interval] per 1-SD increment of log-transformed tHcy 1.38 [1.26-1.50] and 1.18 [1.10-1.26] among stable angina pectoris and AMI patients, respectively) (Pint<0.005 in both cohorts). Further, adding information on the interaction between tHcy and neopterin improved model discrimination and reclassification. tHcy and C-reactive protein were weakly related, and no effect modification was found by C-reactive protein.

CONCLUSIONS

Among patients with coronary heart disease, tHcy predicted risk of AMI only in subjects with concomitantly elevated plasma neopterin. Our results motivate further research on the relationship between homocysteine metabolism, cellular immune activation, and atherothrombosis.

Crosstalk between Tryptophan Metabolism and Cardiovascular Disease, Mechanisms, and Therapeutic Implications

The cardiovascular diseases (CVD) associated with the highest rates of morbidity are coronary heart disease and stroke, and the primary etiological factor leading to these conditions is atherosclerosis. This long-lasting inflammatory disease, characterized by how it affects the artery wall, results from maladaptive immune responses linked to the vessel wall. Tryptophan (Trp) is oxidized in a constitutive manner by tryptophan 2,3-dioxygenase in liver cells, and for alternative cell types, it is catalyzed in the presence of a differently inducible indoleamine 2,3-dioxygenase (IDO1) in the context of a specific pathophysiological environment. Resultantly, this leads to a rise in the production of kynurenine (Kyn) metabolites. Inflammation in the preliminary stages of atherosclerosis has a significant impact on IDO1, and IDO1 and the IDO1-associated pathway constitute critical mediating agents associated with the immunoinflammatory responses that characterize advanced atherosclerosis. The purpose of this review is to survey the recent literature addressing the kynurenine pathway of tryptophan degradation in CVD, and the author will direct attention to the function performed by IDO1-mediated tryptophan metabolism.

Serum level of neopterin is not a marker of disease activity in treated rheumatoid arthritis patients

Neopterin has been measured in many autoimmune diseases and was reported as a marker of cellular immunity activation in rheumatoid asthritis (RA). The aim of this work was to assess serum neopterin as a marker of disease activity in treated RA patients. We measured serum level of neopterin in 120 treated RA patients and 100 age- and sex-matched controls by high-performance liquid chromatography (HPLC) method, and disease activity score was calculated in all patients by DAS28-CRP score. Significantly higher levels of neopterin were observed in RA patients (11.46 ± 3.56 nmol/L) compared to healthy controls (4.74 ± 1.98 nmol/L), P < 0.0001. Significantly higher neopterin levels were observed among male RA patients [median (IQR), 13.44 (12.65-16.21)] than female RA patients [median (IQR), 11.86 (7.91-13.44)], P <0.0001. No significant correlations between neopterin and age, age of disease onset, disease duration, or any of the disease activity parameters were found. Moreover, no significant difference regarding neopterin levels in different disease activity phases was identified. Our results indicated that neopterin is a marker of RA but not a marker of disease activity in treated RA patients.

Decreased circulating neopterin is associated with increased arterial elasticity: a beneficial role of periodontal treatment

BACKGROUND

The aim of this study was to evaluate the effect of periodontal treatment on arterial elasticity and circulating neopterin in patients with moderate to severe periodontitis in a Chinese population.

METHODS

One hundred and eight patients with moderate to severe periodontitis were eligible to take part in the study and were randomized into two groups. The treatment group received intensive periodontal treatment, while the control group received control periodontal treatment. All parameters, including brachial-ankle pulse wave velocity (baPWV), ankle brachial index (ABI), serum neopterin (NP), high-sensitivity C-reactive protein (hs-CRP), Interleukin-6 (IL-6), were evaluated before treatment and 1 month after treatment.

RESULTS

The parameters including NP, hs-CRP, IL-6 and baPWV decreased significantly after 1 month in the treatment group (p < 0.05 for all comparisons) but not in the control group (p > 0.05). There was no significant difference in the change of ABI between the two groups (p = 0.231). A positive correlation was found between the decreased circulating NP and increased arterial elasticity in the treatment group (r = 0.947, p < 0.001).

CONCLUSIONS

This study demonstrates for the first time that the fall in circulating NP induced by periodontal treatment contributes to increased arterial elasticity in patients with moderate and severe periodontitis.

Cellular immune activity biomarker neopterin is associated hyperlipidemia: results from a large population-based study

BACKGROUND

Increased serum neopterin had been described in older age two decades ago. Neopterin is a biomarker of systemic adaptive immune activation that could be potentially implicated in metabolic syndrome (MetS). Measurements of waist circumference, triglycerides, high-density lipoprotein cholesterol (HDLC), systolic and diastolic blood pressure, glycated hemoglobin as components of MetS definition, and plasma total neopterin concentrations were performed in 594 participants recruited in the European Prospective Investigation into Cancer and Nutrition (EPIC).

RESULTS

Higher total neopterin concentrations were associated with reduced HDLC (9.7 %, p < 0.01 for men and 9.2 %, p < 0.01 for women), whereas no association was observed with the rest of the MetS components as well as with MetS overall (per 10 nmol/L: OR = 1.42, 95 % CI = 0.85-2.39 for men and OR = 1.38, 95 % CI = 0.79-2.43).

CONCLUSIONS

These data suggest that high total neopterin concentrations are cross-sectionally associated with reduced HDLC, but not with overall MetS.

Levels of Neopterin and other Inflammatory Markers in Obese and Non-Obese Patients with Polycystic Ovary Syndrome

Background

We aimed to measure the levels of inflammatory markers and neopterin in obese and non-obese patients with PCOS by using 2 separate control groups with matching body mass index (BMI).

Material/Methods

A total of 60 women of reproductive age with (n=30) and without (n=30) PCOS were included in this study. Based on their BMI, patients with PCOS were divided into 2 groups as obese (n=15) and non-obese (n=15) PCOS groups. In addition, 2 BMI-matched control groups were formed. Neopterin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (N/L ratio), and vitamin B12 were assessed by complete blood count.

Results

No significant difference was found between patients with PCOS and control subjects in neopterin, IL-6, TNF-α, and CRP levels. However, N/L ratio levels were significantly higher (p 0.045) and vitamin B12 levels were significantly lower (p 0.033) in patients with PCOS compared to control subjects.

No statistically significant difference was found between obese and non-obese patients with PCOS and control subjects in neopterin, IL-6, TNF-α, and N/L ratio levels. However, CRP levels were significantly higher in obese patients with PCOS compared to obese control subjects (p 0.007).

Conclusions

It can be concluded that inflammatory activity is increased in patients with PCOS, can lead to an increased risk for atherosclerosis, and this increase is not caused by obesity but rather by the polycystic ovary syndrome itself. However, studies with larger sample sizes are needed in this area.

Oxidised low density lipoprotein causes human macrophage cell death through oxidant generation and inhibition of key catabolic enzymes

Oxidised low density lipoprotein (oxLDL) is thought to be a significant contributor to the death of macrophage cells observed in advanced atherosclerotic plaques. Using human-derived U937 cells we have examined the effect of cytotoxic oxLDL on oxidative stress and cellular catabolism. Within 3h of the addition of oxLDL, there was a rapid, concentration dependent rise in cellular reactive oxygen species followed by the loss of cellular GSH, and the enzyme activity of both glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and aconitase. The loss of these catabolic enzymes was accompanied by the loss of cellular ATP and lower lactate generation. Addition of the macrophage antioxidant 7,8-dihydroneopterin inhibited the ROS generation, glutathione loss and catabolic inactivation. NOX was shown to be activated by oxLDL addition while apocynin inhibited the loss of GSH and cell viability. The data suggests that oxLDL triggers an excess of ROS production through NOX activation, and catabolic failure through thiol oxidation resulting in cell death.

Prediction of cardiovascular events in statin-treated stable coronary patients of the treating to new targets randomized controlled trial by lipid and non-lipid biomarkers

Several plasma non-lipid biomarkers have been shown to predict major cardiovascular events (MCVEs) in population studies. Our objective was to investigate the relationship between lipid and non-lipid biomarkers levels achieved during statin therapy and the incidence of MCVEs in patients with stable coronary heart disease (CHD). We conducted a substudy of the TNT (Treating to New Targets) study, which was a randomized trial that compared the efficacy of high (80 mg) versus low (10 mg) dose atorvastatin for the secondary prevention of CHD. Fasting plasma levels of standard lipids and of 18 non-lipid biomarkers were obtained after an 8-week run-in period on atorvastatin 10 mg in 157 patients who experienced MCVEs during the 4.9 years of study follow-up and in 1349 controls. MCVE was defined as CHD death, nonfatal, non-procedure-related myocardial infarction, resuscitated cardiac arrest, and fatal or nonfatal stroke. After adjusting for age, sex and treatment arm, plasma levels of high-density lipoprotein (HDL) cholesterol, triglycerides, high-sensitivity C-reactive protein (hsCRP), insulin, neopterin, N-terminal pro-brain natriuretic peptide (BNP), lipoprotein(a) [Lp(a)], and the soluble receptor for advanced glycation end products (sRAGE) were predictive of recurrent MCVEs (P≤0.02 for each doubling of plasma concentration). However, no significant association was observed between the risk of recurrent MCVEs and plasma levels of low-density lipoprotein cholesterol, adiponectin, cystatin C, lipoprotein-associated phospholipase A2, monocyte chemotactic protein-1, matrix metalloproteinase-9, myeloperoxidase, osteopontin, soluble CD40 ligand, soluble intercellular adhesion molecule-1, or soluble vascular cell adhesion molecule-1. After further adjustment for diabetes, hypertension, smoking, and BMI, the relationship between hsCRP, insulin and MCVE were no longer significant, while the relationship between Lp(a), neopterin, NT-proBNP and sRAGE and MCVE remained statistically significant. In conclusion, in patients with CHD treated with atorvastatin, plasma levels of Lp(a), neopterin, NT-proBNP, and sRAGE are associated with the risk of recurrent MCVEs.

Trial Registration

ClinicalTrials.gov NCT00327691.

Neopterin and beta-2 microglobulin relations to immunity and inflammatory status in nonischemic dilated cardiomyopathy patients

BACKGROUND

The aim of the study was to assess the relationships among serum neopterin (NPT), β2-microglobulin (β2-M) levels, clinical status, and endomyocardial biopsy results of dilated cardiomyopathy patients (DCM).

METHODS

Serum NPT and β-2 M were determined in 172 nonischaemic DCM patients who underwent right ventricular endomyocardial biopsy and 30 healthy subjects (ELISA test). The cryostat biopsy specimens were assessed using histology, immunohistology, and immunochemistry methods (HLA ABC, HLA DR expression, CD3 + lymphocytes, and macrophages counts).

RESULTS

The strong increase of HLA ABC or HLA DR expression was detected in 27.2% patients-group A-being low in 72.8% patients-group B. Neopterin level was increased in patients in group A compared to healthy controls 8.11 (4.50-12.57) versus 4.99 (2.66-8.28) nmol/L (P < 0.05). β-2 microglobulin level was higher in DCM groups A (2.60 (1.71-3.58)) and B (2.52 (1.51-3.72)) than in the control group 1.75 (1.28-1.96) mg/L, P < 0.001. Neopterin correlated positively with the number of macrophages in biopsy specimens (P < 0.05) acute phase proteins: C-reactive proteins (P < 0.05); fibrinogen (P < 0.01); and NYHA functional class (P < 0.05) and negatively with left ventricular ejection fraction (P < 0.05).

CONCLUSIONS

Neopterin but not β-2 microglobulin concentration reflected immune response in biopsy specimens. Neopterin correlated with acute phase proteins and stage of heart failure and may indicate a general immune and inflammatory activation in heart failure.

Tryptophan breakdown is increased in euthymic overweight individuals with bipolar disorder: a preliminary report

OBJECTIVES

Individuals with bipolar disorder (BD) are disproportionately affected by symptoms of being overweight and metabolic syndrome when compared to the general population. The pertinence of this observation is underscored by observations that excess weight is associated with a more complex illness presentation, course, and outcome in BD. We present the first preliminary report of our BIPFAT study, which explored shared hypothesized pathophysiological pathways between being overweight and having BD.

METHODS

We investigated the tryptophan-kynurenine metabolism pathway as a proxy of dysregulated inflammatory homeostasis in euthymic, overweight individuals with BD (n = 78) compared to healthy controls (n = 156).

RESULTS

Both blood kynurenine concentrations and the kynurenine to tryptophan ratio [(Kyn:Trp); an estimate of tryptophan breakdown] were significantly higher in the total sample of euthymic patients with BD, with greater increases noted in both parameters in the subsample of overweight patients with BD. When compared to controls, peripheral neopterin concentrations were significantly lower. Within the BD group, there were also significant between-group differences in neopterin concentrations, with higher levels in those who were overweight and in subjects with BD in the later stages of illness compared to earlier stages.

CONCLUSIONS

Increased tryptophan breakdown, as well as neopterin levels in BD, may be an indirect mediator of immune-mediated inflammation. In BD, this may account for the high prevalence of medical comorbidities and increased mortality. The observation of increased kynurenine levels and Kyn:Trp, and altered circulating neopterin levels provides indirect evidence of increased activity of tryptophan-degrading indoleamine 2,3-dioxygenase in euthymic individuals with BD, underscoring the role of inflammatory mediators as a causative and/or consequent factor. More robust abnormalities in the overweight subsample underscore the additional inflammatory burden of medical comorbidity and suggest a shared pathophysiology as well as a mechanism mediating BD and cardiovascular disease.

Neopterin is associated with cardiovascular events and all-cause mortality in renal transplant patients

BACKGROUND

Inflammatory markers show significant associations with cardiovascular events and all-cause mortality after kidney transplantation. Neopterin, reflecting interferon-γ-release, may better reflect the proinflammatory state of recipients than less specific markers.

METHODS

Kidney transplant recipients in the Assessment of LEscol in Renal Transplant (ALERT) trial were examined and investigated for an association between serum neopterin and subsequent clinical events: graft loss, major cardiovascular events (MACE) and all-cause mortality.

RESULTS

After adjustment for established and emerging risk factors neopterin expressed as neopterin-to-creatinine ratio was significantly associated with MACE (p = 0.009) and all-cause mortality (p = 0.002). Endpoints were more frequent with increasing quartiles of neopterin-to-creatinine ratio. The incidence rates of MACE and all-cause mortality were significantly increased in the upper quartiles compared with the first.

CONCLUSIONS

This long-term prospective analysis in stable kidney allograft recipients suggests that neopterin is associated with long-term risk of cardiovascular events and all-cause mortality, but not renal outcomes.

Plasma level of neopterin as a marker of disease activity in treated rheumatoid arthritis patients: association with gender, disease activity and anti-CCP antibody

Immune system activation is known to be involved in the progression of rheumatoid arthritis (RA). The pro-inflammatory cytokine interferon-γ in various cells, including monocytes, induces neopterin production. Plasma level of neopterin has been measured in many autoimmune diseases and can be used as a marker of cellular immunity activation. In this study we measured the plasma level of neopterin in 418 treated RA patients and 398 age and sex matched healthy people by high pressure liquid chromatography (HPLC) method. Disease activity score was calculated in all patients by DAS-CRP method. Plasma level of neopterin was compared between RA and control groups. We also determined the association between neopterin level with gender and disease activity score in RA patients. Significantly higher level of neopterin was observed in RA patients compared to healthy controls. Moreover, there was higher neopterin level in male RA patients versus female patients. Plasma neopterin level was increased in patients with active disease and also was correlated with disease activity parameters. There was a significant correlation of plasma level of neopterin with age in both RA and control group and also age of onset and disease duration in RA patients. Anti-CCP positive patients had higher level of neopterin in comparison to anti-CCP negative patients and there was a significant correlation between neopterin level and anti-CCP titer. Our results indicated that neopterin is a sensitive marker for assaying background inflammation and disease activity score in RA patients and may be used as a marker for evaluation of therapy efficacy.

Pathophysiological roles and clinical importance of biomarkers in acute coronary syndrome

Early diagnosis of acute coronary syndrome (ACS) is important to guide appropriate therapy at a time when it is most likely to be of value. Accurate prognostic and risk stratification will facilitate high-risk patients to have early advanced diagnostic investigations and early appropriate interventions in a cost-effective and efficient manner, while those patients at low risk of ACS complications do not need such costly diagnostic tests and unnecessary hospital admission. Recent investigations have demonstrated that elevation of biomarkers upstream from acute-phase biomarkers, biomarkers of plaque destabilization and rupture, biomarkers of myocardial ischemia, necrosis, and dysfunction may provide an earlier assessment of patient risk and identify patients with higher risk of having an adverse event. This review provides an overview of the pathophysiology and clinical characteristics of several well-established biomarkers as well as emerging biomarkers that may have potential clinical utility in patients with ACS. Such emerging biomarkers hold promise and need to be more thoroughly evaluated before utilization in routine clinical practice.

Neopterin negatively regulates expression of ABCA1 and ABCG1 by the LXRα signaling pathway in THP-1 macrophage-derived foam cells

To investigate the effects of neopterin on ABCA1 expression and cholesterol efflux in human THP-1 macrophage-derived foam cells, and to explore the role of the liver X receptor alpha (LXRα) involved. In the present study, THP-1 cells were pre-incubated with ox-LDL to become foam cells. The protein and mRNA expression were examined by Western blot assays and real-time quantitative PCR, respectively. Liquid scintillation counting and high performance liquid chromatography assays were used to test cellular cholesterol efflux and cholesterol content. Neopterin decreased ABCA1 expression and cholesterol efflux in a time- and concentration-dependent manner in THP-1 macrophage-derived foam cells, and the LXRα siRNA can reverse the inhibitory effects induced by neopterin. Neoterin has a negative regulation on ABCA1 expression via the LXRα signaling pathway, which suggests the aggravated effects of neopterin on atherosclerosis.