C-reactive Protein Molecules Research Articles

Estimating Time Window to Administer Anti-Cytokine Therapeutic Drugs to COVID-19 Patients.

The severe COVID-19 infection often leads to "Cytokine Release Syndrome (CRS)", which is a serious adverse medical condition causing multiple organ failures. Anti-cytokine therapy has shown promising results for the treatment of the CRS. As part of the anti-cytokine therapy, the immuno-suppressants or anti-inflammatory drugs are infused to block the release of cytokine molecules. However, determining the time window to infuse the required dose of drugs is challenging due to the complex processes involving the release of inflammatory markers, such as IL-6 and C-reactive protein (CRP) molecules. In this work, we develop a molecular communication channel to model the transmission, propagation, and reception of cytokine molecules. The proposed analytical model can be used as a framework to estimate the time window to administer anti-cytokine drugs to get successful outcomes. Simulation results show that at a 50 s-1 release rate of IL-6 molecules, the cytokine storm is triggered at ~ 10 hours, and consequently, the CRP molecules reach the severe level of 97 mg/L at ~ 20 hours. Further, the results reveal that with one-half of the release rate of IL-6 molecules, the time to observe the severe level of 97 mg/L CRP molecules increases by 50%.

Phosphorylcholine-Functionalized PEDOT-Gated Organic Electrochemical Transistor Devices for Ultra-Specific and Sensitive C-Reactive Protein Detection.

Affinity-based organic electrochemical transistor (OECT) sensors offer an attractive approach to point-of-care diagnostics due to their extreme sensitivity and easy operation; however, their application in the real world is frequently challenged by the poor storage stability of antibody proteins and the interference from biofouling in complex biofluids. In this work, we developed an antibody-free and antifouling OECT biosensor to detect C-reactive protein (CRP) at ultra-high specificity and sensitivity. The key to this novel biosensor is the gate coated by phosphorylcholine-functionalized poly (3,4-ethylene dioxythiophene) (PEDOT-PC), which possesses large capacitance and low impedance, prevents biofouling of bovine serum albumin (BSA) and the fetal bovine serum (FBS), and interacts specifically with CRP molecules in the presence of calcium ions. This PEDOT-PC-gated OECT biosensor demonstrated exceptional sensitivity when detecting the CRP molecules at 10 pg/mL, while significantly depressing the signal from the nonspecific binding. This indicates that this biosensor could detect the CRP molecules directly without nonspecific binding blocking, the usual process for the earlier transistor sensors before detection. We envision that this PEDOT-PC-gated OECT biosensor platform may offer a potentially valuable tool for point-of-care diagnostics as it alleviates concerns about poor antibody stability and BSA blocking inconstancy.

Maternal blood metal concentrations are associated with C-reactive protein and cell adhesion molecules among pregnant women in Puerto Rico.

Background:Studies have revealed a link between aberrant levels of maternal C-reactive protein (CRP) and cell adhesion molecules (CAMs) with adverse birth outcomes. Some epidemiologic studies have indicated that long-term metal exposures can modulate the levels of CRP and CAMs, but the associations between prenatal metal exposures and the levels of CRP and CAMs have yet to be studied more extensively. In this study, we assessed associations between maternal blood metal levels and CRP/CAMs among 617 pregnant women in the Puerto Rico PROTECT birth cohort.Methods:Blood samples were collected from participants at 16–20 (visit 1) and 24–28 (visit 3) weeks gestation. We measured concentrations of 11 metals using inductively coupled plasma mass spectrometry (ICP-MS). From the blood samples, CRP and CAMs intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) were also quantified using a customized Luminex assay. Linear-mixed effects models (LMEs) were used to regress CRP and CAMs on metals and included random intercepts for study participants to account for correlated repeated outcome measures. Fetal sex and visit effects were estimated using interaction terms between metal exposure variables and fetal sex, as well as visit indicators, respectively.Results:We observed significant positive associations between nickel and CRP (Δ: 7.04, 95% CI = 0.75, 13.73) and between lead and VCAM (Δ: 4.57, 95% CI = 1.36, 7.89). The positive associations were mainly driven by mothers carrying male fetuses. We also observed various visit-specific associations. The significant associations between metals and CRP were predominantly driven by visit 3; however, the significant associations between metals and VCAM were mainly driven by visit 1.Conclusion:Certain maternal blood metal levels were significantly associated with CRP and CAMs and most of these associations were differentially driven by fetal sex, as well as by timing in pregnancy. Future studies should further explore metal-CRP/CAMs associations for a better understanding of the underlying mechanism of metal-induced adverse birth outcomes.

Triple signal-enhancing electrochemical aptasensor based on rhomboid dodecahedra carbonized-ZIF67 for ultrasensitive CRP detection

C-reactive protein (CRP) is one of the most sensitive acute-phase reactants, which is an early stage indicator of cardiovascular disease and infectious inflammation in clinic. However, it is still challenging to accurately quantification the trace content of CRP molecules in plasma samples. In this work, we propose an ultrasensitive electrochemical CRP aptasensor based on rhomboid dodecahedra carbonized-ZIF67 loaded with gold nanoparticle modified by aptamer. Aptamer biomolecules are binded to AuNPs via Au-thiol bonds for selectively capturing CRPs. The ultrasensitivity is achieved based on triple signal enhancing strategy: enhancing the specific surface area via the rhomboid dodecahedra structure of ZIF67, increasing the conductivity via carbonization of ZIF67, and multiplying the number of probe molecules via an enzyme catalyzed reaction. Experimental parameters, including the volume of C-ZIF67 dispersion, electrodeposition time of AuNPs, incubation time of aptamer-CRP and aptamer-CRP concentration, are systemically investigated and optimized. Under optimal conditions, the proposed biosensor shows excellent sensing performance with the limit of detection (LOD) of 0.44 pg mL−1 (S/N = 3), and a broad linear dynamic range of 10 pg mL−1 ‒ 10 μg mL−1 within the total readout time of 5 min. This work provides an effective electrochemical biosensor for CRP assay in plasma, being highly potential for applications in bioanalysis and point-of-care (POC) clinical diagnosis.

Endostatin Inhibits Blood-Retinal Barrier Breakdown in Diabetic Rats by Increasing the Expression of ICAM-1 and VCAM-1 and Decreasing the Expression of VEGF.

Endostatin has become the strongest endogenous angiogenesis inhibitor due to suppressing VEGF expression. The purpose of this study was to assess the impact of endostatin on the blood-retinal barrier (BRB) in diabetic rats. SD rats were induced to develop diabetes by streptozotocin, and endostatin was administrated by intravitreal injection. The body weight, the level of blood glucose, the expressions of C-reactive protein (CRP), adhesion molecules intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), junction proteins (occludin, claudin-5, and zonula occluden-1), and VEGF were measured in rats' retinas of diabetes. The BRB breakdown was evaluated using Evans blue. The level of CRP and adhesion molecules (ICAM-1 and VCAM-1) was increased in retinas of diabetic rats, while endostatin significantly inhibited the upregulation of these. Diabetes increased the BRB permeability and retinal thickness. Diabetes also decreased the levels of occludin, claudin-5, and ZO-1 in retinals. These changes were inhibited by endostatin treatment. Upregulation of vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), and protein kinase C- (PKC-) β2 was also reversed by endostatin in retinas of diabetic rats. Endostatin provides protection against diabetic retinopathy, which may involve its barrier-enhancing effects.

Development of a Point-of-Care System Based on White Light Reflectance Spectroscopy: Application in CRP Determination.

The development of methods and miniaturized systems for fast and reliable quantitative determinations at the Point-of-Care is a top challenge and priority in diagnostics. In this work, a compact bench-top system, based on White Light Reflectance Spectroscopy, is introduced and evaluated in an application with high clinical interest, namely the determination of C-Reactive protein (CRP) in human blood samples. The system encompassed all the necessary electronic and optical components for the performance of the assay, while the dedicated software provided the sequence and duration of assay steps, the reagents flow rate, the real-time monitoring of sensor response, and data processing to deliver in short time and accurately the CPR concentration in the sample. The CRP assay included two steps, the first comprising the binding of sample CRP onto the chip immobilized capture antibody and the second the reaction of the surface immunosorbed CRP molecules with the detection antibody. The assay duration was 12 min and the dynamic range was from 0.05 to 200 μg/mL, covering both normal values and acute inflammation incidents. There was an excellent agreement between CRP values determined in human plasma samples using the developed device with those received for the same samples by a standard diagnostic laboratory method.

C-Reactive Protein-Based Strategy to Reduce Antibiotic Dosing for the Treatment of Pneumococcal Infection.

C-reactive protein (CRP) is a component of innate immunity. The concentration of CRP in serum increases in microbial infections including Streptococcus pneumoniae infection. Employing a mouse model of pneumococcal infection, it has been shown that passively administered human wild-type CRP protects mice against infection, provided that CRP is injected into mice within two hours of administering pneumococci. Engineered CRP (E-CRP) molecules have been reported recently; unlike wild-type CRP, passively administered E-CRP protected mice against infection even when E-CRP was injected into mice after twelve hours of administering pneumococci. The current study was aimed at comparing the protective capacity of E-CRP with that of an antibiotic clarithromycin. We established a mouse model of pneumococcal infection in which both E-CRP and clarithromycin, when used alone, provided minimal but equal protection against infection. In this model, the combination of E-CRP and clarithromycin drastically reduced bacteremia and increased survival of mice when compared to the protective effects of either E-CRP or clarithromycin alone. E-CRP was more effective in reducing bacteremia in mice treated with clarithromycin than in untreated mice. Also, there was 90% reduction in antibiotic dosing by including E-CRP in the antibiotic-treatment for maximal protection of infected mice. These findings provide an example of cooperation between the innate immune system and molecules that prevent multiplication of bacteria, and that should be exploited to develop novel combination therapies for infections against multidrug-resistant pneumococci. The reduction in antibiotic dosing by including E-CRP in the combination therapy might also resolve the problem of developing antibiotic resistance.

Treatment of Pneumococcal Infection by Using Engineered Human C-Reactive Protein in a Mouse Model.

C-reactive protein (CRP) binds to several species of bacterial pathogens including Streptococcus pneumoniae. Experiments in mice have revealed that one of the functions of CRP is to protect against pneumococcal infection by binding to pneumococci and activating the complement system. For protection, however, CRP must be injected into mice within a few hours of administering pneumococci, that is, CRP is protective against early-stage infection but not against late-stage infection. It is assumed that CRP cannot protect if pneumococci got time to recruit complement inhibitor factor H on their surface to become complement attack-resistant. Since the conformation of CRP is altered under inflammatory conditions and altered CRP binds to immobilized factor H also, we hypothesized that in order to protect against late-stage infection, CRP needed to change its structure and that was not happening in mice. Accordingly, we engineered CRP molecules (E-CRP) which bind to factor H on pneumococci but do not bind to factor H on any host cell in the blood. We found that E-CRP, in cooperation with wild-type CRP, was protective regardless of the timing of administering E-CRP into mice. We conclude that CRP acts via two different conformations to execute its anti-pneumococcal function and a model for the mechanism of action of CRP is proposed. These results suggest that pre-modified CRP, such as E-CRP, is therapeutically beneficial to decrease bacteremia in pneumococcal infection. Our findings may also have implications for infections with antibiotic-resistant pneumococcal strains and for infections with other bacterial species that use host proteins to evade complement-mediated killing.

Intravenous omega-3 fatty acids are associated with better clinical outcome and less inflammation in patients with predicted severe acute pancreatitis: A randomised double blind controlled trial.

Omega-3 fatty acids (FA) can ameliorate the hyper-inflammatory response that occurs in conditions such as severe acute pancreatitis (SAP) and this may improve clinical outcome. We tested the hypothesis that parenteral omega-3 FA from a lipid emulsion that includes fish oil could be beneficial in patients with predicted SAP by reducing C-reactive protein (CRP) concentration (primary outcome), and modulating the inflammatory response and improving clinical outcome (secondary outcomes). In a phase II randomized double-blind single-centre controlled trial, patients with predicted SAP were randomised to receive a daily infusion of fish oil containing lipid emulsion (Lipidem® 20%, BBraun) for 7 days (n=23) or a daily infusion of a lipid emulsion without fish oil (Lipofundin® MCT 20%, BBraun) (n=22). On admission, both groups had comparable pancreatitis predicted severity and APACHE II scores. Administration of fish oil resulted in lower total blood leukocyte number (P=0.04), CRP (P=0.013), interleukin-8 (P=0.05) and intercellular adhesion molecule 1 (P=0.01) concentrations, multiple organ dysfunction score, sequential organ failure assessment score (P=0.004), early warning score (P=0.01), and systemic inflammatory response syndrome (P=0.03) compared to the control group. The fish oil group had fewer new organ failures (P=0.07), lower critical care admission rate (P=0.06), shorter critical care stay (P=0.03) and shorter total hospital stay (P=0.04). It is concluded that intravenous administration of a fish oil containing lipid emulsion, a source of omega-3 FA, improves clinical outcomes in patients with predicted SAP, benefits that may be linked to reduced inflammation. CLINICALTRIALS. NCT01745861. EudraCT (2010-018660-16).

Pro-Inflammatory Markers in Relation to Cardiovascular Disease in HIV Infection. A Systematic Review

BackgroundIn the past years many inflammatory markers have been studied in association with clinically manifest cardiovascular disease (CVD) and carotid intima-media thickness (CIMT) in HIV-infected patients, to obtain insights in the increased cardiovascular risk observed in HIV infection. This systematic review provides an oversight of the current knowledge.MethodsA search was performed in PubMed, Embase and Cochrane in July 2014, identifying all articles from 1996 onwards addressing the relation between inflammatory markers and CVD or CIMT in HIV-positive adults. Two authors, using predefined criteria, independently conducted the selection of articles, critical appraisal and extraction of the data. Analysis was focused on the immune markers that were most frequently assessed. The review protocol was registered in the PROSPERO database at 11 July 2014 (registration number CRD42014010516). This review was performed according to the PRISMA guideline.FindingsForty articles were selected; eight addressing cardiovascular disease (CVD) and thirty-two addressing CIMT. C-reactive protein (CRP), interleukin-6 (IL-6) and d-dimer were assessed most frequently in relation to the occurrence of CVD; in four out of eight studies. All three markers were positively related to CVD in three out of four studies. Studies addressing CIMT were too heterogeneous with respect to patient populations, inflammatory markers, CIMT measurement protocols and statistical methods to allow for a formal meta-analysis to obtain summary statistics. CRP, IL-6 and soluble vascular cell adhesion molecule (sVCAM-1) were the most studied markers in relation to CIMT. None of the inflammatory markers showed an association with CIMT.InterpretationThis review showed a relation between some inflammatory markers and CVD, however, no consistent relation is observed for CIMT. Statistical approaches that yields effect estimates and standardized CIMT protocols should be chosen. Further research should focus on prospective studies and a selected set of inflammatory markers.

Solubilization and purification of recombinant modified C-reactive protein from inclusion bodies using reversible anhydride modification.

The precise function of C-reactive protein (CRP) as a regulator of inflammation in health and disease continues to evolve. The true understanding of its role in host defense responses has been hampered by numerous reports of comparable systems with contradictory interpretations of CRP as a stimulator, suppressor, or benign contributor to such processes. These discrepancies may be explained in part by the existence of a naturally occurring CRP isoform, termed modified CRP (i.e., mCRP), that is expressed when CRP subunits are dissociated into monomeric structures. The free mCRP subunit undergoes a non-proteolytic conformational change that has unique solubility, antigenicity, and bioactivity compared to the subunits that remain associated in the native, pentameric CRP molecule (i.e., pCRP). As specific reagents have been developed to identify and quantify mCRP, it has become apparent that this isoform can be formed spontaneously in calcium-free solutions. Furthermore, mCRP can be expressed on perturbed cell membranes with as little as 24–48 h incubation in tissue culture. Because mCRP has the same size as pCRP subunits as evaluated by SDS-PAGE, its presence in a pCRP reagent would not be apparent using this technique to evaluate purity. Finally, because many antibody reagents purported to be specific for “CRP” contains some, or substantial specificity to mCRP, antigen-detection techniques using such reagents may fail to distinguish the specific CRP isoform detected. All these caveats concerning CRP structures and measurements suggest that the aforementioned contradictory studies may reflect to some extent on distinctive bioactivities of mCRP rather than on pCRP. To provide a reliable, abundant supply of mCRP for separate and comparable studies, a recombinant protein was engineered and expressed in E. coli (i.e., recombinant mCRP or rmCRP). Synthesized protein was produced as inclusion bodies which proved difficult to solubilize for purification and characterization. Herein, we describe a method using anhydride reagents to effectively solubilize rmCRP and allow for chromatographic purification in high yield and free of contaminating endotoxin. Furthermore, the purified rmCRP reagent represents an excellent comparable protein to the biologically produced mCRP and as a distinctive reagent from pCRP. Deciphering the true function of CRP in both health and disease requires a knowledge, understanding, and reliable supply of each of its structures so to define the distinctive effects of each on the body’s response to tissue damaging events.

Effect of a high dose of vitamin D on a rabbit model of atherosclerosis.

Multifactorial factors have been involved in atherosclerosis. An association has been shown between osteoporosis and carotid atherosclerosis. This work evaluates the effect of vitamin D on regression of atherosclerosis. Forty-eight male rabbits were divided into: Group Ia: [Standard diet + saline for 4 weeks]; Group I b: [Standard diet + a high dose of vitamin D3 daily for 4 weeks]; Group IIa: [Cholesterol–enriched diet for 4 weeks]; Group IIb: [Cholesterol–enriched diet + a single high dose of vit D3, daily for 4 weeks. At the end of 4 weeks, the rabbits were sacrificed for assay in serum lipid profile, C reactive protein (CRP), vitamin D3 metabolite, calcium, soluble adhesion molecules (sVCAM and sICAM) and nitrite (NO) and malondialdehyde (MDA) released from isolated aortic rings. Results showed that vitamin D produced a significant reduction in the sera of lipid profile, CRP, and adhesion molecules, associated with a non-significant change in serum calcium and a significant increase in the body level of vitamin D3. Addition of vitamin D to the incubated aortic rings of the atherosclerotic rabbits resulted in a significant increase in NO and decrease in MDA release. It could be concluded that vitamin D has anti-atherosclerotic effects, and may exert these effects by inhibiting lipid peroxidation and stimulation of nitric oxide, resulting in attenuation of the inflammatory atherosclerotic process.

Infusion of Pharmaceutical-Grade Natural Human C-Reactive Protein Is Not Proinflammatory in Healthy Adult Human Volunteers

Baseline circulating concentrations of C-reactive protein (CRP) are significantly associated with cardiovascular disease risk in general populations. This modest association has been inappropriately conflated with causality, and it has been claimed that CRP is proatherogenic. Most of the known causative factors for atherosclerosis stimulate increased CRP production, but comprehensive genetic epidemiology studies provide no support for a pathogenic role of CRP. The reported proinflammatory effects of human CRP preparations on healthy cells in vitro and in healthy animals in vivo have all been produced by poorly characterized CRP preparations, demonstrably caused by impurities, or elicited by CRP made in recombinant Escherichia coli not by humans. None of the in vitro or animal findings have been reproduced with pure natural human CRP. Nevertheless, the strong proinflammatory effects of infusing recombinant bacterial CRP into humans have still been inappropriately ascribed to CRP. To investigate the effects of infusion into healthy adult human volunteers of pure natural human CRP. Comprehensively characterized, pharmaceutical-grade, endotoxin-free, purified CRP, prepared to GMP standard from pooled normal human donor plasma was infused as an intravenous bolus in 7 healthy adult human volunteers at ≤2 mg/kg to provide circulating CRP concentrations ≤44 mg/L. No recipient showed any significant clinical, hematologic, coagulation, or biochemical changes, or any increase in proinflammatory cytokines or acute phase proteins. The human CRP molecule itself is not proinflammatory in healthy human adults.

Single C-Reactive Protein Molecule Detection on a Gold-Nanopatterned Chip Based on Total Internal Reflection Fluorescence

Single C-reactive protein (CRP) molecules, which are non-specific acute phase markers and products of the innate immune system, were quantitatively detected on a gold-nanopatterned biochip using evanescent fieldenhanced fluorescence imaging. The 4 × 5 gold-nanopatterned biochip (spot diameter of 500 nm) was fabricated by electron beam nanolithography. Unlabeled CRP molecules in human serum were identified with single-molecule sandwich immunoassay by detecting secondary fluorescence generated by total internal reflection fluorescence (TIRF) microscopy. With decreased standard CRP concentrations, relative fluorescence intensities reduced in the range of 33.3 zM-800 pM. To enhance fluorescence intensities in TIRF images, the distance between biochip surface and CRP molecules was optimally adjusted by considering the quenching effect of gold and the evanescent field intensity. As a result, TIRF only detected one single-CRP molecule on the biochip the first time.

Sterol Regulatory Element-Binding Factor 2 (SREBF-2) Predicts 7-Year NAFLD Incidence and Severity of Liver Disease and Lipoprotein and Glucose Dysmetabolism

We prospectively assessed the impact of a sterol regulatory element-binding factor-2 (SREBF-2) polymorphism on the risk of developing nonalcoholic fatty liver disease (NAFLD) and on liver histology and lipoprotein and glucose metabolism in biopsy-proven NAFLD. In a population-based study, we followed 175 nonobese, nondiabetic participants without NAFLD or metabolic syndrome at baseline, characterized for the SREBF-2 rs133291 C/T polymorphism, dietary habits, physical activity, adipokines, C-reactive protein (CRP), and endothelial adhesion molecules. A comparable cohort of NAFLD patients underwent liver biopsy, an oral glucose tolerance test with minimal model analysis to yield glucose homeostasis parameters, and an oral fat tolerance test with measurement of plasma lipoproteins, adipokines, and cytokeratin-18 fragments. After 7 years, 27% of subjects developed NAFLD and 5% developed diabetes. SREBF-2 predicted incident NAFLD and diabetes and CRP and endothelial adhesion molecule changes. In biopsy-proven NAFLD patients, SREBF-2 predicted nonalcoholic steatohepatitis (odds ratio 2.92 [95% CI 2.08–4.18], P = 0.002) and the severity of tissue insulin resistance, β-cell dysfunction, and oral fat intolerance (characterized by higher postprandial lipemia, cholesterol enrichment of triglyceride-rich lipoproteins and oxidized LDLs, HDL cholesterol fall, adipokine imbalance, and postprandial apoptosis activation). An SREBF-2 polymorphism predisposes individuals to NAFLD and associated cardiometabolic abnormalities and affects liver histology and glucose and lipid metabolism in biopsy-proven NAFLD.

An aptamer based competition assay for protein detection using CNT activated gold-interdigitated capacitor arrays

An aptamer can specifically bind to its target molecule, or hybridize with its complementary strand. A target bound aptamer complex has difficulty to hybridize with its complementary strand. It is possible to determine the concentration of target based on affinity separation system for the protein detection. Here, we exploited this property using C-reactive protein (CRP) specific RNA aptamers as probes that were immobilized by physical adsorption on carbon nanotubes (CNTs) activated gold interdigitated electrodes of capacitors. The selective binding ability of RNA aptamer with its target molecule was determined by change in capacitance after allowing competitive binding with CRP and complementary RNA (cRNA) strands in pure form and co-mixtures (CRP:cRNA=0:1, 1:0, 1:1, 1:2 and 2:1). The sensor showed significant capacitance change with pure forms of CRP/cRNA while responses reduced considerably in presence of CRP:cRNA in co-mixtures (1:1 and 1:2) because of the binding competition. At a critical CRP:cRNA ratio of 2:1, the capacitance response was dramatically lost because of the dissociation of adsorbed aptamers from the sensor surface to bind when excess CRP. Binding assays showed that the immobilized aptamers had strong affinity for cRNA (Kd=1.98μM) and CRP molecules (Kd=2.4μM) in pure forms, but low affinity for CRP:cRNA ratio of 2:1 (Kd=8.58μM). The dynamic detection range for CRP was determined to be 1–8μM (0.58–4.6μg/capacitor). The approach described in this study is a sensitive label-free method to detect proteins based on affinity separation of target molecules that can potentially be used for probing molecular interactions.

High-Sensitive C-Reactive Protein: Universal Prognostic and Causative Biomarker in Heart Disease?

C-reactive protein (CRP), a pentraxin protein, is an established marker of acute phase reactions. There is some experimental evidence that the CRP molecule could be causative in all stages of atherosclerotic disease starting from endothelial dysfunction, continuing to plaque formation and destabilization, and to atherothrombotic complications. However, each claim of causality has elicited a counterpoint argument, and Mendelian randomization studies have confidently shown that the concentration of CRP is unlikely to be causative. Meta-analyses have attributed a 1.5-1.7-fold risk to one standard deviation increase of high-sensitive CRP (a high-sensitivity CRP assay) for major cardiovascular events after adjustments for classical risk factors. Additional adjustments for metabolic factors reduced the risk to approximately 1.2-1.4-fold, which is still significant. Of interest, high-sensitive CRP also predicted all-cause and cancer mortality. Driven by the JUPITER trial that showed a benefit on outcome for treatment with rosuvastatin in primary prevention, treatment has been recommended in patients with a moderate Framingham Risk Score with a high-sensitive CRP of >2 mg/l. However, adding CRP to risk charts and biomarker panels mostly yielded small and inconsistent improvements.

Molecular switching fluorescence based high sensitive detection of label-free C-reactive protein on biochip

A novel detection technique on biochip for the quantification of label-free C-reactive protein (CRP) based on molecular switching of fluorescence (MSF) is demonstrated by total internal reflection fluorescence microscopy. It alters fluorescence intensity of fluoreseinamine isomer 1 (FAI) upon binding with its specific ligand, O-phosphorylethanolamine (PEA). In the MSF-based detection, FAI was used as an ink, printed on a 3-glycidoxypropyl-trimethoxysilane (GPTS)-coated glass coverslip. With the addition of GPTS conjugated PEA solution to the FAI-printed coverslip, the fluorescence intensity was remarkably decreased. Addition of CRP increased fluorescence intensity linearly in the range of 800 aM to 500 fM ( R = 0.997). The MSF-based biochip assay for the estimation of CRP in human sera showed ∼200 times increased detection sensitivity in less than a third of the time to obtain results using a conventional enzyme-linked immunosorbent assay. This biochip detection is a promising new technique for the quantification of CRP molecules from trace amounts of clinical samples.

High sensitive detection of C-reactive protein by total internal reflection fluorescence microscopy on rapidly making nanoarray protein chip

This study investigated a method for the high sensitivity detection and quantification of the C-reactive protein (CRP) in human serum using total internal reflection fluorescence microscopy (TIRFM) on a rapidly made nanoarray protein chip. The nanoarray biotin-probe was patterned onto 3-mercaptopropyl trimethoxysilane-coated cover glass with a spot diameter of approximately 400nm within 1min using a NanoeNabler-based surface patterning tool. The unlabeled CRP molecules were detected in human sera using TIRFM, based on a sandwich fluorescence immunoassay. The linear regression for standard CRP in the range of 50zM-1fM was determined using the equation y=0.437x+84.991 (R=0.9993). This proposed method was approximately 2000 times faster than conventional atomic force microscopy based dip-pen nanolithography in terms of the chip manufacturing process. Additionally this method was 6 x 10(6) times more sensitive than enzyme-linked immunosorbent assay and exhibited a wide dynamic linear range (50zM-1fM).

Regulation of cell function by isoforms of C-reactive protein: a comparative analysis.

Despite the emerging evidence suggesting a proatherogenic role of C-reactive protein (CRP) in atherosclerosis, the contribution of CRP in pathogenesis of atherosclerosis and atherothrombosis has not been unequivocally defined. The role of CRP in pathophysiology/pathology seems to largely depend on its structure. Two CRP isoforms, the native pentameric and the modified monomeric one, differ substantially in their physiological functions, which is thought to origin from the considerable structural heterogeneity of the CRP molecule. The present review provides an overview of the experimental evidence with relevance to the clinical role(s) of various CRP isoforms. The biological role of the protein, its structure and distribution are discussed with particular emphasis on the diverse properties of the pentameric and monomeric forms of CRP. Some methodological aspects, related to experimental models and techniques of CRP preparation, are also critically reviewed.