A novel common single nucleotide polymorphism in the promoter region of the C-reactive protein gene associated with the plasma concentration of C-reactive protein

Inflammatory biomarkers and long-term outcome in young patients three months after a first myocardial infarction

BACKGROUND

Studies on predictive value of circulating inflammatory biomarkers after myocardial infarction (MI) have often been limited by blood sampling only in an acute setting and short follow-up time. We aimed to compare the long-term predictive value of nine inflammatory biomarkers, known to be involved in atherosclerosis, in young patients investigated three months after a first-time MI.

METHODS

Nine biomarkers (high-sensitivity C-reactive protein, interleukin (IL)-6, IL-18, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-1, MMP-3, MMP-9, serum amyloid A and tumor necrosis factor-alfa) were sampled in 382 young (<60 years) patients and in age and sex-matched controls, three months after a first-time MI between 1996 and 2000. Swedish national patient registers were used to determine cardiovascular (CV) outcomes during 20 years of follow-up.

RESULTS

In cases, random forest models identified IL-6 as the most important predictor of the primary composite endpoint of death, heart failure (HF) or MI hospitalization, and the separate endpoints death and HF hospitalization. IL-18 was the most important predictor of MI hospitalization. In a Cox regression, the highest tertile of IL-6 was associated with the composite endpoint (HR (95% CI) 1.91 (1.31-2.79)), death (2.38 (1.42-3.98)) and HF hospitalization (2.70 (1.32-5.50)), when adjusting for age, sex and CV risk factors. The highest tertile of IL-18 was associated with MI hospitalization (2.31 (1.08-4.91)) when severity of coronary atherosclerosis was added to the same type of model.

CONCLUSIONS

When nine inflammatory markers involved in atherosclerosis were analyzed three months after the acute event in young MI patients, IL-6 and IL-18 were the most important biomarkers to predict long-term CV outcomes during 20 years of follow-up.

Inflammatory markers and androstenedione modify the effect of serum testosterone on obesity among men: Findings from a Chinese population

BACKGROUND

Few studies are available on the relationship of androstenedione with inflammation and obesity and the effect of androstenedione and inflammation on the association between testosterone and obesity. This study intended to examine the mediation effect of inflammatory markers on the association of testosterone with obesity and the moderation effect of androstenedione on the association of testosterone with inflammation and obesity in Chinese rural men.

MATERIALS AND METHODS

This cross-sectional research enrolled 2536 male rural inhabitants from the Henan Rural Cohort study. The serum concentrations of testosterone and androstenedione were determined by liquid chromatography-tandem mass spectrometry. Linear and logistic regression were used to examine the relationships between testosterone, inflammatory markers, and obesity. Mediation and moderation analyses were carried out to evaluate the potential effects of inflammatory markers on the relationship between testosterone and obesity, as well as androstenedione on the relationships of testosterone with inflammation and obesity.

RESULTS

After adjusting for confounding factors, the results showed that testosterone and androstenedione were negatively related to obesity, and inflammatory markers were positively associated with obesity. Besides, testosterone and androstenedione were negatively associated with inflammatory markers. Mediation analysis showed that white blood cell, neutrophil, monocyte, and high-sensitivity C-reactive protein had mediating effects on the association between testosterone and obesity. The most vital mediator was high-sensitivity C-reactive protein, and its proportion of the effect was 11.02% (defined by waist circumference), 11.15% (defined by waist-to-hip ratio), 12.92% (defined by waist-to-height ratio), and full mediating effect (defined by body mass index). Moreover, androstenedione played negative moderation effects on the associations of testosterone with inflammation and obesity.

CONCLUSION

Inflammatory markers and androstenedione were first found to have modifying effects on the association of testosterone with obesity. Higher levels of testosterone and androstenedione could reduce the inflammation level and risk of obesity, indicating their potential roles in the prevention and treatment of chronic diseases.

Single nucleotide variations in the development of diabetic foot ulcer: A narrative review

Diabetes mellitus has become a global health problem, and the number of patients with diabetic foot ulcers (DFU) is rapidly increasing. Currently, DFU still poses great challenges to physicians, as the treatment is complex, with high risks of infection, recurrence, limb amputation, and even death. Therefore, a comprehensive understanding of DFU pathogenesis is of great importance. In this review, we summarized recent findings regarding the DFU development from the perspective of single-nucleotide variations (SNVs). Studies have shown that SNVs located in the genes encoding C-reactive protein, interleukin-6, tumor necrosis factor-alpha, stromal cell-derived factor-1, vascular endothelial growth factor, nuclear factor erythroid-2-related factor 2, sirtuin 1, intercellular adhesion molecule 1, monocyte chemoattractant protein-1, endothelial nitric oxide synthase, heat shock protein 70, hypoxia inducible factor 1 alpha, lysyl oxidase, intelectin 1, mitogen-activated protein kinase 14, toll-like receptors, osteoprotegerin, vitamin D receptor, and fibrinogen may be associated with the development of DFU. However, considering the limitations of the present investigations, future multi-center studies with larger sample sizes, as well as in-depth mechanistic research are warranted.

Analysis of Genetic Variants in the Glucocorticoid Receptor Gene NR3C1 and Stenosis of the Carotid Artery in a Polish Population with Coronary Artery Disease

Background: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Early diagnosis and elimination of risk factors are crucial for better managing CVDs. Atherosclerosis, whose development might be associated with glucocorticoids (GCs), is a critical factor in the development of carotid artery (CA) stenosis and most other CVDs. Aim: To investigate the association of Tth111I, N363S, and ER22/23EK-NR3C1 polymorphisms and the incidence of CA stenosis. Methods: The study group consisted of 117 patients diagnosed with coronary artery disease (CAD) and CA stenosis and 88 patients with CAD and ruled out CA stenosis. Genomic DNA was extracted from blood, and genotyping was carried out using Tth111I, N363S, and ER22/23EK-NR3C1 polymorphism sequencing. Results: No significant association between studied polymorphisms and the incidence or the severity of CA stenosis in the Polish population with CAD was found. Conclusion: This is the first study that proves that common NR3C1 gene variants do not influence CA stenosis and probably are not associated with atherosclerosis. The search for genes that can act as prognostic markers in predicting CA stenosis is still ongoing.

CRP levels are significantly associated with CRP genotype and estrogen use in The Lifestyle, Biomarker and Atherosclerosis (LBA) study

Background

The C-reactive protein (CRP) is an important biomarker for atherosclerosis and single nucleotide polymorphisms (SNPs) in the CRP locus have been associated with altered CRP levels and associated with risk for cardiovascular disease. However, the association between genetic variations in the CRP gene, estrogen use and CRP levels or early signs of atherosclerosis in young healthy individuals is not fully characterized. We aimed to evaluate the influence of five genetic variants on both plasma CRP levels and carotid intima-media thickness (cIMT) values, including aspects on estrogen containing contraceptive use in females.

Methods

Genotyping was performed with TaqMan real time PCR and compared with high sensitivity CRP serum levels in 780 Swedish young, self-reported healthy individuals. Haplotypes of the SNPs were estimated with the PHASE v 2.1. The cIMT was measured by 12 MHz ultrasound. The contraceptive use was self-reported.

Results

Strong associations between CRP and genotype were observed for rs3091244, rs1800947, rs1130864, and rs1205 in women (all p < 0.001). In men, only rs1800947 was associated with CRP (p = 0.029). The independent effect of genotypes on CRP remained significant also after adjustment for established risk factors. Female carriers of the H1/ATGTG haplotype had higher CRP than non-carriers. This was specifically pronounced in the estrogen-using group (p < 0.001), and they had also higher cIMT (p = 0.002) than non-carriers but with a small cIMT difference between the haplotype groups (0.02 mm). In parallel, a significant correlation between CRP and cIMT in the estrogen using group was observed (r = 0.194; p = 0.026).

Conclusions

Estrogen use, genotypes and haplotypes in the CRP locus are significantly associated with CRP levels. Based on an observed interaction effect between sex/estrogen use and the H1/ATGTG haplotype on CRP, and a marginally thicker cIMT in the estrogen using group, our data suggest that both genotypes and estrogen usage could be involved in arterial wall structural differences. The causality between CRP levels and cIMT remains unclear, and the observed difference in cIMT is not clinically relevant in the present state. Future larger and longitudinal studies may shed further light on the role of more long-term estrogen use and early atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02610-z.

C-Reactive Protein Mediates the Effect of Serum Progesterone on Obesity for Men and Postmenopausal Women in Henan Rural Cohort Study

Purpose

Studies of progesterone with obesity have been lacking, and no prior studies have investigated progesterone and C-reactive protein in rural natural populations. This study aimed to investigate the association of serum progesterone with obesity based on anthropometric parameters in Henan Rural Cohort, then further to explore the potential role of C-reactive protein in this association.

Patients and Methods

A total of 4687 participants (2474 men and 2213 postmenopausal women) from the Henan Rural Cohort study were included. Logistic regression analysis, linear regression analysis, and restricted cubic splines were performed to estimate the relationships between progesterone, C-reactive protein, obesity, and obesity-related parameters. Mediation analysis was carried out to assess the intermediary role of C-reactive protein played in the association between progesterone and obesity.

Results

After controlling for confounders, the odds ratios of obesity no matter how obesity was defined was associated with progesterone (P trend <0.05). Moreover, progesterone was related to obesity-related parameters. Also, C-reactive protein increased with the elevation of progesterone, and C-reactive protein was associated with obesity no matter how obesity was defined (P trend <0.001). Mediation analysis indicated that hsCRP had the mediating effects on the obesity, and the proportion of the effects were 15.35% and full mediating effect (defined by body mass index), 15.46% and 12.24% (defined by waist circumference), 19.14% and 12.12% (defined by waist-to-hip ratio), 23.81% and 15.09% (defined by waist-to-height ratio) for men and postmenopausal women, relatively.

Conclusion

In the Chinese rural men and postmenopausal women population, progesterone and C-reactive protein are related to obesity. We firstly found C-reactive protein partly mediates the effect of progesterone on obesity, indicating that systemic inflammation played a critical role in the association.

Quantile-dependent expressivity of serum C-reactive protein concentrations in family sets

Background

“Quantile-dependent expressivity” occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., C-reactive protein, CRP) is high or low relative to its distribution. We have previously shown that the heritabilities (h²) of coffee and alcohol consumption, postprandial lipemia, lipoproteins, leptin, adiponectin, adiposity, and pulmonary function are quantile-specific. Whether CRP heritability is quantile-specific is currently unknown.

Methods

Serum CRP concentrations from 2,036 sibships and 6,144 offspring-parent pairs were analyzed from the Framingham Heart Study. Quantile-specific heritability from full-sib (β_FS, h² ={(1 + 8r_spouseβ_FS)^0.5 − 1}/(2r_spouse)) and offspring-parent regression slopes (β_OP, h² = 2β_OP/(1 + r_spouse)) were estimated robustly by quantile regression with nonparametric significance determined from 1,000 bootstrap samples.

Results

Quantile-specific h² (±SE) increased with increasing percentiles of the offspring’s age- and sex-adjusted CRP distribution when estimated from β_OP (P_trend = 0.0004): 0.02 ± 0.01 at the 10th, 0.04 ± 0.01 at the 25th, 0.10 ± 0.02 at the 50th, 0.20 ± 0.05 at the 75th, and 0.33 ± 0.10 at the 90th percentile, and when estimated from β_FS (P_trend = 0.0008): 0.03±0.01 at the 10th, 0.06 ± 0.02 at the 25th, 0.14 ± 0.03 at the 50th, 0.24 ± 0.05 at the 75th, and 0.53 ± 0.21 at the 90th percentile.

Conclusion

Heritability of serum CRP concentration is quantile-specific, which may explain or contribute to the inflated CRP differences between CRP (rs1130864, rs1205, rs1800947, rs2794521, rs3091244), FGB (rs1800787), IL-6 (rs1800795, rs1800796), IL6R (rs8192284), TNF-α (rs1800629) and APOE genotypes following CABG surgery, stroke, TIA, curative esophagectomy, intensive periodontal therapy, or acute exercise; during acute coronary syndrome or Staphylococcus aureus bacteremia; or in patients with chronic rheumatoid arthritis, diabetes, peripheral arterial disease, ankylosing spondylitis, obesity or inflammatory bowel disease or who smoke.

Association between CRP and TNF-α genes Variants and Cardiovascular Heart Disease in a Mexican Population: Protocol for a Case-Control Study

BACKGROUND

The C-reactive protein (CRP) and the tumor necrosis factor-alpha (TNF-α) are considered markers of inflammation and have been shown to predict the risk of incident cardiovascular events. However, few studies have undertaken a comprehensive examination of SNPs (single nucleotide polymorphisms) of the CRP and TNF-α genes; due to this, we will present a protocol study to evaluate the role of the CRP and TNF-α genes in Mexican individuals.

METHODS/DESIGN

we will perform a case-control study to explore the CRP and TNF-α genotype distribution as well as the serum influence of rs1800947, rs1130864, rs2794521 and rs1205 (polymorphisms of the CRP gene) and rs361525, rs1800629, rs1799724, rs1800630, rs1799964 (of the TNF-α gene) in Mexican individuals who present coronary artery disease.

ETHICS AND DISSEMINATION

a written informed consent will be obtained from all the participating subjects. An article detailing the results of the study will be submitted for publication in an international peer-reviewed journal, in accordance with STROBE criteria.

A micro RNA-146a polymorphism is associated with coronary restenosis

The association of the miRNA-146a polymorphism rs2910164 with atherosclerosis and restenosis was investigated. We found no association with atherosclerosis; however, we found a negative association for the G/C (P = 0.007) and a positive association for the C/C genotype with the risk of restenosis, which is the main drawback for cardiac surgery.

C-reactive protein and coronary heart disease: all said--is not it?

C-reactive protein (CRP) and coronary heart disease (CHD) have been the subject of intensive investigations over the last decades. Epidemiological studies have shown an association between moderately elevated CRP levels and incident CHD whereas genetic studies have shown that polymorphisms associated with elevated CRP levels do not increase the risk of ischemic vascular disease, suggesting that CRP might be a bystander rather than a causal factor in the progress of atherosclerosis. Beside all those epidemiological and genetic studies, the experimental investigations also try to reveal the role of CRP in the progress of atherosclerosis. This review will highlight the complex results of genomic, epidemiological, and experimental studies on CRP and will show why further studies investigating the relationship between CRP and atherosclerosis might be needed.

Sialic acid level reflects the disturbances of glycosylation and acute-phase reaction in rheumatic diseases

In the rheumatic diseases, the changes in the carbohydrate part of serum glycoproteins occur and these abnormalities can be monitored by serum level of total and free sialic acid. The aim of this study was to evaluate the total and free sialic acid level as a marker of inflammation activity (TSA) and the changes in glycosylation of blood glycoproteins (FSA) in rheumatoid arthritis (RA), systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). Studies were carried out in 50 patients with RA, 24 with SLE and 32 with SSc. TSA concentration was measured with an enzymatic, colorimetric method and FSA with a thiobarbituric method. The serum levels of TSA in RA and SLE patients were significantly increased compared to controls and in RA patients were higher than that in SSc patients. The mean serum level of FSA in RA patients was significantly higher, but in SSc patients significantly lower than that in the controls, and in RA patients was significantly higher than in SLE and in SSc patients. All acute-phase proteins were changed: Positive acute-phase proteins were elevated, and the negative protein was decreased. The positive acute-phase proteins positively correlated with the levels of TSA and FSA in RA and SSc patients. In SLE patients, TSA positively correlated with haptoglobin and α1-antitrypsin. In RA patients, there was the positive correlation of TSA and FSA with DAS 28. The changes in the serum levels of TSA and FSA in the course of rheumatic diseases could reflect the abnormalities in glycosylation/sialylation patterns of glycoproteins induced by acute-phase response.

Genomic organization of the cytosolic manganese superoxide dismutase gene from the Pacific white shrimp, Litopenaeus vannamei, and its response to thermal stress

Cytosolic manganese superoxide dismutase (cMnSOD) is an important antioxidant enzyme which catalyzes the conversion of superoxides to oxygen and hydrogen peroxide in several organisms. In the Pacific white shrimp, Litopenaeus vannamei, three cMnSOD genes (LvcMnSOD1-3) have previously been characterized. Here, the genomic structure of LvcMnSOD2 and its mRNA expression in response to thermal stress was examined. Analysis of the nucleotide sequence demonstrated that LvcMnSOD2 is comprised of 2392 bp spanning from the ATG translation start site to the stop codon and contains six exons interrupted by five introns. The 5' region upstream of the LvcMnSOD2 gene contains several putative regulatory elements but lacks the accepted TATA sequence. The putative transcription factor binding elements that may be involved in LvcMnSOD2 mRNA expression level include activator protein-1 (AP-1), cAMP response element binding protein (CREB), upstream stimulatory factor (USF), CAAT-enhancer binding protein (C/EBP), nuclear factor-κB (NF-κB) and heat shock regulatory element (HSE). In addition, we compared the 5' upstream sequences of the LvcMnSOD2 gene between two shrimp strains that are resistant or susceptible to Taura syndrome virus (TSV), respectively, which revealed the absence of the USF and C/EBP elements at positions -2125 and -1986, respectively, in the TSV-susceptible shrimp line. Moreover, genomic variations between the two shrimp strains were detected in some of the putative C/EBP, USF, HSE and NF-κB transcription factor binding elements. That these genomic variations might be involved in the TSV resistance as well as in stress responses remains to be evaluated. The presence of 15 putative HSEs suggests that the expression of LvcMnSOD2 is regulated under thermal stress. Here, we found that in response to a 1 or 3 h thermal stress (35 °C), the mRNA expression levels of LvcMnSOD2 were significantly increased and then gradually decreased in the recovering phase at room temperature (25 °C) to control levels by 3 h after the heat shock. Thus, the antioxidant system may be induced to protect cells from the oxidative damage caused by thermal stress. The genomic organization of LvcMnSOD2 likely provides a clue to the mechanisms that might regulate the antioxidant defense pathway in shrimps and so potentially in marine invertebrates.

Human C-reactive protein gene polymorphism and metabolic syndrome are associated with premature coronary artery disease

The aim of this study was to investigate the association between C-reactive protein (CRP) gene polymorphism and metabolic syndrome (MetS) with premature coronary artery disease (PCAD). 116 patients with PCAD (58 with MetS and 58 without MetS) and 119 controls were included in the study. CRP gene +1059 G>C polymorphism was analyzed by polymerase chain reaction. Serum hs-CRP was measured using high-sensitivity enzyme-linked immunosorbent assay. Carriers of C allele of the CRP +1059 G>C polymorphism had 3.37 fold increased risk to develop MetS in patients with PCAD. In addition CRP gene and hs-CRP levels were independent risk factors for PCAD and MetS. The present study provides new evidence that the presence of CRP +1059 G>C polymorphism and hs-CRP levels are independent determinants of PCAD and MetS in Egyptians. The results of our study suggest a synergistic effect of CRP C allele with classical risk factors such as hypertension, obesity, dyslipidemia and MetS.

Correlation of C-reactive protein level and obesity in Chinese adults and children: a meta-analysis

This meta-analysis evaluated the correlations between C-reactive protein (CRP) and obesity in Chinese adults and children. We searched three Chinese databases [Wanfang, WEIPU, and Chinese National Knowledge Infrastructure (CNKI)] in addition to PubMed. The search was restricted to only Chinese studies published online before January 9, 2013. Data from 28 articles were independently abstracted by two reviewers. The articles' characteristics were abstracted as follows: 1) first author name; 2) year of publication; 3) study population; 4) sample size; 5) sex, age, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and CRP level of the study population; 6) Pearson correlation coefficients, Spearman correlation coefficients, or odds ratios between CRP level and obesity. The metaanalysis was conducted to pool the Pearson correlation coefficients using a random-effects model. The pooled Pearson correlation coefficient between CRP and BMI was 0.45 [95% confidence interval (CI): 0.33-0.56] in Chinese adults and 0.46 (95% CI: 0.31-0.62) in Chinese children, and the pooled Pearson correlation coefficient was 0.32 (95% CI: 0.24-0.40) in the general Chinese population and 0.53 (95% CI: 0.42-0.64) in the obese Chinese population. Significant correlation was thus found between CRP and obesity in Chinese adults and children.

Association between CRP gene polymorphism 717A/G, C-reactive protein and neurological deficit in ischemic stroke

Inflammatory components play an important role in the pathogenesis of arteriosclerosis, one of the main causes of stroke. Blood C-reactive protein (CRP) level is connected with the severity of neurological deficit and disability after stroke. Production of CRP depends on CRP gene polymorphism. This study enrolled 125 patients with ischemic stroke. CRP 717A/G polymorphism was tested in all patients along with an assay of CRP levels measured on the first and tenth day after stroke onset. Neurological deficit on admission and before discharge from hospital was evaluated according to National Institutes of Health Stroke Scale (NIHSS), and then associated with CRP levels and the CRP polymorphism. The CRP 717AA genotype was the most frequent, observed in 53.6% of patients; AG genotype in 40%, and GG genotype in 6.4%. Carriers of the 717GG genotype had a significantly higher CRP level on the first day after stroke versus heterozygotes (p=0.023). The improvement in neurological state evaluated with the NIHSS was significantly better in CRP 717AA patients in comparison with other CRP 717 genotypes (p=0.035). A higher level of CRP on the first day after ischemic stroke was slightly associated with the CRP 717AG genotype. The CRP 717AA genotype promotes improvement of neurological state in patients with ischemic stroke.

Neonatal infections in Saudi Arabia: association with C-reactive protein, CRP -286 (C>T>A) gene polymorphism and IgG antibodies

Background

C-reactive protein (CRP) is a nonspecific, acute-phase protein that rises in response to infectious and non-infectious inflammatory processes. Infections are the single largest cause of neonatal deaths globally.

The primary aim of this study is to examine the association between CRP gene polymorphism and serum levels of CRP in correlation with early onset sepsis (EOS) infection in newborns living in Taif city, Saudi Arabia. The second aim is to examine the relationship between specific IgG/IgG subclasses and early onset sepsis (EOS) infection among these newborns.

Methods

Staphylococcus aureus (S. aureus) is one of the most common organisms related to sepsis infection in the newborn at King Abdel Aziz Specialist Hospital (KAASH). This study was conducted in Taif city, at KAASH’s neonatal intensive care unit between March and August 2012. Neonates were consecutively enrolled onto the study having met our inclusion criteria (as per our research protocol).

The CRP concentration level was analysed using NycoCard® CRP Single Test. CRP -286 (C>T>A) A polymorphisms were analyzed using Pyrosequencing technology for CRP genotyping. IgG subclasses were analysed in the study population using ELISA.

Result

Logistic regression analyses showed that the AA and AC genotypes were negatively associated amongst EOS neonates compared to suspected neonates. The frequency of CC and CT were significantly associated with the EOS neonates compared to the suspected group. The levels of specific IgG1, IgG2 and IgG3 antibodies were significantly lower amongst EOS compared to the suspected group.

Conclusions

Taken together, the CRP-286 (C>T>A) A genotype polymorphism and specific IgG antibodies isotype levels can contribute to a reduced risk of EOS. Furthermore, CRP has a potential use in detecting EOS in neonates, which may mean earlier detection and management of EOS and subsequently better clinical outcome.

C-reactive protein 1059G/C gene polymorphism, C-reactive protein levels and acute myocardial infarction

AIMS

High-sensitivity C-reactive protein (hs-CRP) is an inflammatory marker, predicting the occurrence of acute myocardial infarction (AMI). Genetic predisposition to high baseline CRP might account for a high risk of heart diseases. Our study aimed at investigating an association of CRP 1059G/C gene polymorphism with plasma CRP levels and AMI in Egyptian patients.

METHODS

Genotypes of 150 patients with AMI and 150 healthy sex and age-matched controls were analyzed using PCR-restriction fragment length polymorphism methods. hs-CRP concentrations were assessed.

RESULTS

There was no significant association between CRP 1095G/C polymorphism and AMI. However, individuals with GG genotype had significantly higher plasma CRP concentration than those with GC and CC genotypes, in both controls (3.82 ± 1.03 vs. 2.34 ± 0.7; P = 0.001) and patients with AMI (8.39 ± 2.6 vs. 6.67 ± 2.4; P = 0.005).

CONCLUSION

Our results revealed that CRP 1059G/C gene variation influences plasma CRP levels. Conversely, this polymorphism was not associated with the risk for AMI.

Genome-wide association with C-reactive protein levels in CLHNS: evidence for the CRP and HNF1A loci and their interaction with exposure to a pathogenic environment

Recent genome-wide association studies have related several genetic loci, including C-reactive protein (CRP), hepatocyte nuclear factor 1 homeobox (HNF1A), and genetic variations in the leptin receptor (LEPR), to circulating CRP levels in populations of European ancestry. The genetic effects in other populations and across varying levels of exposure to a pathogenic environment, an important environmental factor associated with CRP, remain to be determined. We tested 2,073,674 single-nucleotide polymorphisms (SNPs) for association with plasma CRP (limited to ≤10 mg/L) in 1,709 unrelated Filipino women from the Cebu Longitudinal Health and Nutrition Survey. The strongest evidence of association was observed with variants at CRP (rs876537, P = 1.4 × 10(-9)) and HNF1A (rs7305618, P = 1.0 × 10(-8)). Among other previously reported CRP-associated loci, the apolipoprotein E ε4 haplotype was associated with decreased CRP level (P = 7.1 × 10(-4)), and modest association was observed with LEPR (rs1892534, P = 0.076), with direction of effects consistent with previous studies. The strongest signal at a locus not previously reported mapped to a gene desert region on chromosome 6q16.1 (rs1408282, P = 2.9 × 10(-6)). Finally, we observed nominal evidence of interaction with exposure to a pathogenic environment for top main effect SNPs at HNF1A (rs7305618, P = 0.031), LEPR (rs1892535, P = 0.030) and 6q16.1 (rs1408282, P = 0.046). Our findings demonstrate convincing evidence that genetic variants in CRP and HNF1A contribute to plasma CRP in Filipino women and provide the first evidence that exposure to a pathogenic environment may modify the genetic influence at the HNF1A, LEPR, and 6q16.1 loci on plasma CRP level.

The polymorphisms of C-reactive protein gene modify the association between central obesity and lung function in taiwan asthmatics

High-sensitivity C-reactive protein (hs-CRP) concentrations and obesity are proposed to have a significant relationship with impairment of lung function, but little has been reported to date on the association between CRP gene and lung function. We studied the association of three tagSNPs (tag single nucleotide polymorphisms) of CRP gene and their interactions with central obesity on lung function. A total of 384 asthmatic adults and 384 controls who were 1:1 matched by sex and age were recruited for this study. Three tagSNPs polymorphisms for CRP rs1417938, rs1800947 and rs1205 were selected from HapMap data and genotyping by using TaqMan allelic discrimination assay. A questionnaire interview, body composition and pulmonary function tests were performed. CRP single nucleotide polymorphisms (SNPs) did not increase the risk of asthma, but CRP rs1205 CC genotype significantly decreased the predictive value of forced vital capacity (FVC) in the asthma group (adjusted mean change = -7.54%, 95% CI = -13.82 to -1.25%). Waist-to-hip ratio, not body mass index, also decreased the predictive value of FVC in asthmatics. The subjects with central obesity who carried CRP SNPs have a significant reduction effect in lung function. The current results suggest that central obesity may play a major role in lung function, and these effects were modified significantly by the polymorphisms for CRP gene.

Study of C-reactive protein and myocardial infarction in the Indian population

To analyse the association of high sensitivity C-reactive (hsCRP) protein levels and -717A/G single nucleotide polymorphism of CRP with acute myocardial infarction (AMI) in the Indian population. Study population included 100 MI cases wherein 32 patients had experienced previous MI (MI-Group-1), 68 MI cases were recruited at presentation (MI-Group-2) and equal number of age and gender matched healthy individuals. hsCRP levels were determined by ELISA and genotyping of -717A/G was carried out by polymerase chain reaction-based restriction digestion method. The -717A/G genotypes did not influence hsCRP level and their distribution did not differ between groups. However, in the present study hsCRP demonstrated significant correlation with BMI in controls of both the genders and with triglycerides in females of AMI at presentation who otherwise are with low risk profile. Identifying traditional risk factors associated with inflammation may help in controlling the acute event.

C-reactive protein (CRP) gene polymorphisms: implication in CRP plasma levels and susceptibility to acute myocardial infarction

C-reactive protein (CRP) is one of the many molecular factors involved in pathogenesis of coronary artery disease which its plasma levels are associated with increased risk of cardiovascular events. The present study designed to determine whether polymorphisms in the CRP gene are associated with plasma CRP levels and susceptibility to acute myocardial infarction (AMI). Plasma CRP levels were measured in patients with AMI and control subjects and genomic DNA and peripheral blood mononuclear cells (PBMCs) were extracted. The -717A/G and 1059G/C CRP polymorphisms were detected. The mRNA expression of CRP gene and plasma levels of CRP and interleukin-6 (IL-6) were also analyzed. The -717A/G variation was significantly associated with higher CRP levels, but 1059G/C variation was associated with lower CRP levels. The AA genotype frequency of -717A/G variation was significantly more frequent in the patients than control subjects. By contrast, the genotype and allele distribution in 1059G/C of patient were not statistically different between patients and controls. There were significant differences in circulating levels of CRP and IL-6 in the patients than in controls. The mRNA expression levels of CRP were significantly higher in the patient plasma compared with controls. Our results indicate relationship between many polymorphisms in CRP gene and risk of AMI which suggest that genetic variations in CRP might be helpful for determining susceptibility to AMI in Iranian patients. In addition, CRP gene polymorphisms are associated with plasma CRP levels and susceptibility to AMI might be related to CRP gene expression which affects its plasma levels.

C reactive protein and alpha1-antitrypsin: relationship between levels and gene variants

The first step in laboratory diagnosis of alpha1-antitrypsin deficiency (AATD) is the determination of alpha1-antitrypsin (AAT) serum levels; these levels in turn are influenced by the inflammatory status. C reactive protein (CRP) has been proposed as a marker of systemic inflammation. Single nucleotide polymorphisms (SNPs) in the CRP gene have been associated with differences in baseline CRP levels. The purpose of this study was to investigate the relationship between CRP and AAT in the AATD diagnostic setting and to verify whether variations in the CRP gene could influence CRP. We determined AAT and CRP levels in 362 consecutive dried blood spot (DBS) samples submitted for AATD diagnosis and genotyped 3 CRP gene SNPs (rs1205, rs3093077, and rs3091244) associated with variations in serum CRP concentrations. To this aim, we developed a method to measure CRP in a DBS with a good correlation with CRP measurement in serum (r2=0.9927). We showed then that systemic inflammatory status parallels increased levels of AAT (80% of subjects with intermediate AATD and a CRP>0.8 mg/dL had an AAT level above the cut-off of 113 mg/dL) and that this increase might mask the presence of AATD variants. No association was detected between CRP levels and the 3 CRP gene polymorphisms. Simultaneous determination of CRP and AAT is useful in the correct diagnosis of heterozygotes carrying intermediate AATD genotypes; their genetic influence on the CRP level is negligible.

Polymorphism in the C-reactive protein (CRP) gene affects CRP levels in plasma and one early marker of atherosclerosis in men: The Health 2000 Survey

BACKGROUND

C-reactive protein (CRP) is an inflammatory protein that may play a role in the pathogenesis of cardiovascular disease (CVD). However, its status as a causal risk factor is still controversial. CRP gene single nucleotide polymorphisms (SNPs) have been shown to associate with CRP concentration, but not convincingly with early atherosclerotic changes.

OBJECTIVE

We assessed whether CRP genotypes or their haplotypes associate with plasma CRP levels or carotid artery intima-media thickness (IMT) or carotid artery elasticity (CAE) in a Finnish middle-aged study population.

METHODS

We genotyped CRP gene polymorphisms -717A>G (rs2794521), -286C>T>A (rs3091244), +1059G>C (rs1800947), +1444C>T (rs1130864) and +1846G>A (rs1205) and measured CRP concentration in a sub-population (N=1332, mean age 58.2 ± 8.0, women n=727 and men n=605) of a large Finnish cross-sectional health examination survey, The Health 2000 Study, carried out in 2000-2001. Results. Significant association (both sexes p<0.0001, women p=0.015 and men p=0.029) was found between CRP rs1800947 genotype and CRP concentration. Multivariate analysis showed an independent effect of the genotype on CRP concentration after adjustment for risk factors (women p=0.036 and men p=0.009). Similar associations were seen at the haplotype level in haplotype ACCCA where +1059 C-carriers had lower median CRP values than non-carriers (p=0.008). One CRP genotype (rs1130864) was associated with one CAE parameter in men but no association was observed between CRP genotypes and carotid artery IMT.

CONCLUSIONS

CRP gene allelic variation is associated with CRP levels in both sexes and with one CAE parameter (SI) in men in a population-based Finnish cohort of middle-aged subjects.

Inflammatory gene variants in the Tsimane, an indigenous Bolivian population with a high infectious load

The Tsimane of lowland Bolivia are an indigenous forager-farmer population living under conditions resembling pre-industrial European populations, with high infectious morbidity, high infection and inflammation, and shortened life expectancy. Analysis of 917 persons ages 5 to 60+ showed that allele frequencies of 9 SNPs examined in the apolipoprotein E (apoE), C-reactive protein (CRP), and interleukin-6 (IL-6) genes differed from some European, African, and north Asian-derived populations. The apoE2 allele was absent, whereas four SNPs related to CRP and IL-6 were monomorphic: CRP (rs1800947, rs3093061, and rs3093062) and IL-6 (rs1800795). No significant differences in apoE, CRP, and IL-6 variants across age were found CRP levels were higher in carriers of two CRP proinflammatory SNPs, whereas they were lower in carriers of apoE4. Taken together the evidence for (1) different allele frequencies between the Tsimane and other populations and (2) the correlations of CRP and apoE alleles with blood CRP may suggest that these variants are under selection in response to a high infection environment.

Effect of the rs2259816 polymorphism in the HNF1A gene on circulating levels of c-reactive protein and coronary artery disease (the ludwigshafen risk and cardiovascular health study)

Background

C-reactive protein is a well established marker of inflammation and has been used to predict future cardiovascular disease. It is still controversial if it plays an active role in the development of cardiovascular disease. Recently, polymorphisms in the gene for HNF1α have been linked to the levels of C-reactive protein and coronary artery disease.

Methods

We investigated the association of the rs2259816 polymorphism in the HNF1A gene with the circulating level of C-reactive protein and the hazard of coronary artery disease in the LURIC Study cohort.

Results

Compared to CC homozygotes, the level of C-reactive protein was decreased in carriers of at least one A-allele. Each A-allele decreased CRP by approximately 15%. The odds ratio for coronary artery disease was only very slightly increased in carriers of the A-allele and this association did not reach statistical significance.

Conclusions

In the LURIC Study cohort the A-allele of rs2259816 is associated with decreased CRP but not with coronary artery disease.

Genetic polymorphism of the C-reactive protein (CRP) gene and a deep infection focus determine maximal serum CRP level in Staphylococcus aureus bacteremia

C-reactive protein (CRP) is widely used in early detection of sepsis or organ dysfunction. Several single nucleotide polymorphisms (SNPs) in the CRP gene are shown to be associated with variability of basal CRP. To clarify the effect of these SNPs to CRP response in systemic infections, we compared genetic and clinical data on patients with Staphylococcus aureus bacteremia (SAB). Six SNPs in the CRP gene region (rs2794521, rs30912449, rs1800947, rs1130864, rs1205 and rs3093075) were genotyped in 145 patients and analyzed for associations with CRP and various clinical outcomes. We found that the rare minor A-allele of triallelic SNP rs30912449 (C > T > A) and presence of a deep infection focus were strongly associated to the higher maximal CRP during the first week of SAB. Median of the maximal CRP in patients who had the A-minor allele was 282 mg/L (interquartile range [IQR, defined as the difference between the third quartile and the first quartile], 169 mg/L) but only 179 mg/L (IQR, 148 mg/L) in patients without this allele (P = 0.004), and CRP in patients who had deep infection focus was higher 208 mg/L (IQR, 147 mg/L) than in other patients 114 mg/L (IQR, 121 mg/l) (P < 0.0001). Mortality, degree of leucocytosis, time to defervescence or number of deep infections were not affected by CRP gene SNPs. The maximal CRP during the first week in SAB was partly determined by variation in the CRP gene and partly by presence of deep infection focus. This finding suggests cautiousness in interpreting exceptionally high CRPs from SAB patients and comparison between patients.

Association of common polymorphisms in IL10, and in other genes related to inflammatory response and obesity with colorectal cancer

OBJECTIVE AND METHODS

The association of 17 candidate single nucleotide polymorphisms (SNPs) in IL10 and other immune response genes (CRP, TLR4, IL6, IL1B, IL8, TNF, RNASEL) and genes related to obesity (PPARG, TCF7L2, ADIPOQ, LEP) with colorectal cancer was investigated. Haplotype tagging SNPs were chosen for IL10, CRP, and TLR4. Incident colorectal cancer cases (n = 208) and matched controls (n = 381) were identified between baseline in 1989 and 2003 among participants in the CLUE II cohort. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression.

RESULTS

Compared with the AA genotype at the candidate IL10-1082 locus (rs1800896), carrying one (OR, 0.79; 95% CI, 0.53-1.18) or two (OR, 0.58; 95% CI, 0.35-0.95) G alleles, a known higher producer of the anti-inflammatory cytokine IL-10, was associated with lower risk of colorectal cancer (p trend = 0.03). Statistically significant associations with colorectal cancer were observed for three tagSNPs in IL10 (rs1800890, rs3024496, rs3024498) and one common haplotype, but these associations were due to high linkage disequilibrium with IL10-1082. Two CRP haplotypes (global p = 0.04) and TLR4 tagSNPs (rs7873784, rs11536891), but not TLR4 haplotypes, were associated with colorectal cancer.

CONCLUSIONS

Our study suggests that polymorphisms in IL10, and also possibly in CRP and other genes related to immune response or obesity may be associated with colorectal cancer.

Association of a single nucleotide polymorphism in the C-reactive protein gene (-286) with susceptibility to Plasmodium falciparum malaria

The role of inflammation in malaria pathogenesis is not fully understood, although C-reactive protein (CRP) may have a negative influence on host immunity to infections. An upstream polymorphism, -286 (C > T > A), in the CRP gene is known to influence CRP levels. In this study, a cohort of 192 Sudanese donors, followed for malaria infection for 9 years, had their CRP -286 gene locus genotyped by pyrosequencing. The number of malaria episodes experienced by each individual over the study period was used as an index for malaria susceptibility. The prevalence of the CRP alleles A, C and T were 21%, 52% and 27%, respectively. Importantly, the A-allele, unlike the C- and T-alleles or CRP genotypes, was significantly associated with an increased number of malaria episodes, P = 0.007. The proportion of A-allele carriers among donors not known to have had malaria during the study period was 18%, whereas it was 43% and 63% among donors who had experienced 1-4 and > or =5 malaria episodes, respectively, over the same period (P = 0.002). Furthermore, the A-allele was associated with higher parasite counts. In conclusion, the CRP -286 A-allele was associated with an increased susceptibility to uncomplicated Plasmodium falciparum malaria.

Does elevated C-reactive protein cause human atherothrombosis? Novel insights from genetics, intervention trials, and elsewhere

PURPOSE OF REVIEW

To evaluate evidence from human epidemiology, mechanistic studies, animal studies, human genetics, and human intervention trials to address whether elevated C-reactive protein (CRP) causes human atherothrombotic cardiovascular disease.

RECENT FINDINGS

Human epidemiology demonstrates that elevated CRP levels are associated with increased risk of atherothrombosis. Mechanistic and animal studies provide evidence both for and against a causal relationship of CRP with atherothrombosis. Human genetics demonstrate that genetic variation in the CRP gene is associated with lifelong increased CRP levels, but not with increased risk of atherothrombosis. A human intervention trial in healthy people with low LDL cholesterol and elevated CRP demonstrated that aggressive statin treatment caused reductions of 50% in LDL cholesterol, 37% in CRP, 50% in atherothrombotic cardiovascular events, 20% in total mortality, and 45% in venothrombotic events. Importantly, the maximal atherothrombotic treatment benefits were obtained in those who achieved the lowest levels of both LDL cholesterol and CRP.

SUMMARY

Given the data available in mid-2009, elevated CRP per se does not seem to cause atherothrombotic cardiovascular disease, which questions whether CRP-reducing agents will prevent these diseases. However, inflammation per se possibly contributes to atherothrombotic and venothrombotic disease, and CRP measurement may be used in risk assessment and treatment monitoring in atherothrombotic cardiovascular disease.

C-Reactive Protein Gene Polymorphisms in Disease Susceptibility and Clinical Manifestations of Korean Systemic Lupus Erythematosus

Objective.

C-reactive protein (CRP) is a sensitive marker of inflammation. It is hypothesized that polymorphism of CRP gene contributes to susceptibility to systemic lupus erythematosus (SLE). We tested this hypothesis by identifying CRP gene polymorphisms in Korean patients with SLE.

Methods.

Approximately 1.5 kb of CRP promoter region was screened for single nucleotide polymorphism (SNP) using direct sequencing and 3 SNP in CRP exons by restriction fragment length polymorphism. The basal levels of CRP were measured by immunoturbidimetry. The effect of −390 C>A or T polymorphism on the promoter activity was analyzed by luciferase reporter assay in Hep3B cells.

Results.

Allele frequency at polymorphisms within CRP promoter and exon in our Korean patients with SLE differed from that of Caucasians. The A allele was a major allele at position 2043 in Korean SLE patients, whereas G is a major allele in Caucasian SLE. Our SLE patients had minor allele in the −390 polymorphism more frequently versus controls (p = 0.033). CRP 1185 polymorphism was associated with thrombocytopenia (p = 0.043). The basal levels of CRP were significantly higher in individuals who had minor allele in −390 and 2043 polymorphisms (p = 0.03. p = 0.024, respectively). Promoter-reporter construct carrying the −390 A or T allele displayed significantly higher promoter activity than that with the −390 C allele (p < 0.001).

Conclusion.

CRP gene −390 polymorphism plays a role in disease susceptibility of SLE through regulation of serum CRP level. Our results suggest that elevated basal CRP level may be important in the pathogenesis of SLE, even though CRP responsiveness to noninfectious inflammation of SLE is decreased.

Marked differences in CRP genotype frequencies between the Fulani and sympatric ethnic groups in Africa

Background

C-reactive protein (CRP) is an acute phase protein that can activate various immune cells and bind to certain Fcγ receptors. The latter may compete with the binding of IgG antibodies to these receptors and could thereby interfere with the antigen-specific immune response. Polymorphisms in the promoter region of the CRP gene have been strongly associated with the plasma concentration of CRP. The known lower susceptibility to malaria in the Fulani ethnic group, as compared to their sympatric neighbours in Africa, has been linked to different genetic backgrounds. The present study was performed to investigate if polymorphisms in the CRP gene could contribute to the lower susceptibility to malaria seen in the Fulani ethnic group.

Methods

The CRP -717 T>C, -286 C>T>A, and +1444 C>T polymorphisms were analysed in asymptomatic Fulani and non-Fulani individuals from Mali and Sudan using Pyrosequencing T and TaqMan r MGB probes.

Results

The rare -286 A allele, previously shown to be associated with increased CRP expression and plasma levels, was shown to be more frequent in the non-Fulani ethnic groups as compared to the sympatric Fulani ethnic group both in Mali and Sudan. The common -717 T allele was more prevalent in the non-Fulani ethnic group compared to the sympatric Fulani ethnic group, but only in Mali. The parasite prevalence was increased for the -286 A allele, but not for the -717 T allele. No differences regarding genotype frequency or parasite prevalence were seen for +1444 C>T.

Conclusion

This study indicate that CRP may play an important role in the immune responses to malaria, and that the -286 C/T/A CRP polymorphism may be a contributing factor to the lower susceptibility to malaria seen in the Fulani.

C-Reactive protein gene variants are associated with postoperative C-reactive protein levels after coronary artery bypass surgery

Background

Elevated baseline C-reactive protein (CRP) levels are associated with increased risk for developing cardiovascular disease. Several CRP gene variants have been associated with altered baseline CRP levels in ambulatory populations. However, the influence of CRP gene variants on CRP levels during inflammatory states, such as surgery, is largely unexplored. We describe the association between candidate CRP gene variants and postoperative plasma CRP levels in patients undergoing primary, elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB).

Methods

Using a multicenter candidate gene association study design, we examined the association between seventeen candidate CRP single nucleotide polymorphisms (SNPs) and inferred haplotypes, and altered postoperative CRP levels in 604 patients undergoing CABG surgery with CPB. Perioperative CRP levels were measured immediately prior to surgery, post-CPB and on postoperative days (POD) 1–4.

Results

CRP levels were significantly elevated at all postoperative time points when compared with preoperative levels (P < 0.0001). After adjusting for clinical covariates, the minor allele of the synonymous coding SNP, rs1800947 was associated with lower peak postoperative CRP levels (P = 2.4 × 10^-4) and lower CRP levels across all postoperative time points (P = 4.8 × 10^-5). rs1800947 remained highly significant after Bonferroni adjustment for multiple comparisons.

Conclusion

We identified a CRP gene SNP associated with lower postoperative CRP levels in patients undergoing CABG surgery with CPB. Further investigation is needed to clarify the significance of this association between CRP gene variants and the acute-phase rise in postoperative CRP levels with regard to the risk of adverse postoperative outcomes.

C-reactive protein genotypes and haplotypes, polymorphisms in NSAID-metabolizing enzymes, and risk of colorectal polyps

INTRODUCTION

C-reactive protein (CRP) is a nonspecific marker of inflammation linked to cardiovascular disease and possibly colon cancer. Polymorphisms in CRP have been associated with differential CRP concentrations among healthy adults, with some evidence for functional effects on CRP expression.

METHODS

A linkage disequilibrium-based tag single nucleotide polymorphism (SNP)-selection algorithm identified six tagSNPs for Europeans (-821A>G, -390C>T/A, 90A>T, 838G>C, 2043G>A, and 4363C>A), defining six haplotypes with more than 1% frequency. In a case-control study of adenomatous (n=491) or hyperplastic (n=184) polyps versus polyp-free controls (n=583) we investigated these SNPs in relation to colorectal polyp risk.

RESULTS

Individuals with 838 GC or CC genotypes had a modestly, although not statistically significantly, increased risk of adenomas (odds ratio: 1.4 95% confidence interval: 0.9-2.1) and a nearly 2-fold increased risk of concurrent adenomas and hyperplastic polyps (odds ratio: 2.0 95% confidence interval: 1.1-3.6). Increased risk for concurrent adenomas and hyperplastic polyps was also observed for haplotype ACACAC. No other main associations were detected. Risk of adenomas associated with 2043G>A differed with nonsteroidal anti-inflammatory drug (NSAID) use. Among NSAID nonusers, there was a suggestion that the GA or AA genotypes were associated with decreased risk of adenomas; this was not seen among NSAID users (P interaction=0.03). We also observed interactions between UGT1A1 [TA](7) promoter repeat polymorphism and CRP tagSNPs -390C>T/A and 90A>T, in which only the homozygous variant CRP genotype was associated with increased risk of adenoma among those with the UGT1A1 6rpt/6rpt genotype (P interaction=0.02 and 0.04 for -390C>T/A and 90A>T, respectively).

CONCLUSION

These results provide limited support for associations between genetic variation in CRP and colorectal polyp risk. The observed interactions should be evaluated further.

C-Reactive Protein Gene Polymorphisms in Biopsy-proven Giant Cell Arteritis from Northwestern Spain

Objective.

To investigate the potential implication of several polymorphisms of the C-reactive protein (CRP) gene in the predisposition to or clinical expression of giant cell arteritis (GCA).

Methods.

A total of 125 patients diagnosed with biopsy-proven GCA and 234 ethnically matched controls from the Lugo region of Northwestern Spain were included in our study. Four functional gene polymorphisms for CRP rs1417938, rs1800947, rs1205, and rs3093059 variants were assessed using a polymerase chain reaction system with predeveloped TaqMan allelic discrimination assay.

Results.

Although we observed a significant increase in the frequency of heterozygotes for rs1417938 A/T [odds ratio (OR) = 1.70; 95% confidence interval (CI) 1.04–2.80; p = 0.03] and rs1205 C/T (OR 1.73; 95% CI 1.07–2.78; p = 0.02) in patients with GCA, no statistically significant differences in the allelic frequencies of these 2 polymorphisms were found between patients with GCA and controls. A marginal significant increase in the frequency of rs3093059 allele T in patients with GCA compared to controls was observed (OR 1.81; 95% CI 0.97–3.39; p = 0.04). However, the increased frequency of patients with GCA homozygous for rs3093059 T/T in patients with GCA compared to controls was out of the range of significance (OR 1.77; 95% CI 0.92–3.40; p = 0.07). No significant differences were found when we stratified patients with GCA according to the presence of polymyalgia rheumatica or severe ischemic complications of the disease.

Conclusion.

The functional CRP gene polymorphisms assessed in our study do not seem to play a major role in the pathogenesis of GCA in individuals from Northwestern Spain.

Association between C-reactive protein gene haplotypes and C-reactive protein levels in Taiwanese: interaction with obesity

OBJECTIVE

The level of C-reactive protein (CRP), an inflammatory marker that predicts future cardiovascular events, is a heritable trait. Our aim was to test the statistical associations between variations in the CRP gene and serum CRP levels in a Taiwanese population with interaction analysis.

METHODS

A sample population of 617 Taiwanese subjects was enrolled. Five CRP single nucleotide polymorphisms (SNPs) previously reported to be associated with CRP level and with reasonable coverage of the CRP gene region were analyzed using polymerase chain reaction and restriction enzyme digestion or by TaqMan SNP Genotyping Assays.

RESULTS

After adjusting for clinical covariates, minor alleles of 3 of the 5 SNPs were associated with change in CRP level: rs3091244 and rs1205 were associated with increased CRP level (P=0.001 and P<0.001, respectively) and rs1800947 with decreased CRP level (P=0.003). Two haplotypes inferred from 5 SNPs (GCGCG and AAGCG) were associated with increased CRP level (P=0.017 and P<0.0001, respectively). Interaction analysis revealed interaction of obesity with CRP genotypes associated with high CRP level (interaction P=0.034 and 0.020 for SNPs rs2794521 and rs1800947, respectively). An effect of obesity on CRP level was also noted in haplotype interaction analysis with the association occurring predominantly in obese subjects (P=0.034).

CONCLUSION

CRP polymorphisms are independently associated with increased or decreased CRP level in Taiwanese. Further, CRP genotypes/haplotypes interact with obesity to set CRP level. These findings have implications for the prediction of atherosclerotic disease.

Association between the AGTR1 polymorphism +1166A>C and serum levels of high-sensitivity C-reactive protein

Genetic factors have been shown to influence high-sensitivity C-reactive protein (hsCRP) levels, however, which genes that are involved in this process remains to be clarified. The renin-angiotensin system (RAS) is of importance for the regulation of inflammation, and blockade of angiotensin II type 1 receptors (AGTR1) influences hsCRP levels. These findings prompted us to investigate whether a polymorphism in the AGTR1 gene may influence hsCRP levels. Additionally, a polymorphism in the CRP gene that has previously been shown to influence hsCRP levels was genotyped. Serum levels of hsCRP were measured in 270 42-year-old women recruited from the population registry. Two single nucleotide polymorphisms were analysed: +1166A>C and +1444C>T of the AGTR1 and CRP gene, respectively. The A allele of the AGTR1 polymorphism +1166A>C was dose-dependently associated with higher hsCRP levels (p=0.014, adjusted for confounding factors and multiple comparisons). hsCRP levels were not significantly influenced by the CRP +1444C>T genotype; however, an interaction between the two studied polymorphisms with respect to hsCRP levels was observed (p=0.018). The significant association between the AGTR1 polymorphism and hsCRP levels, which appears to be independent of anthropometric and metabolic traits, is yet another indication of a direct influence of RAS on inflammation.

Relationships between disease activity and serum and fecal biomarkers in patients with Crohn's disease

BACKGROUND & AIMS

The quantitative relationships between instruments and assays that measure clinical, endoscopic, and biologic disease activity in patients with Crohn's disease are poorly characterized. This study evaluated the correlations between the Crohn's Disease Activity Index (CDAI), the Simple Endoscopic Score for Crohn's Disease (SES-CD), serum high-sensitivity C-reactive protein (hsCRP) (both phenotype and genotype) and interleukin-6 (IL-6), and fecal calprotectin and lactoferrin.

METHODS

A total of 164 patients with Crohn's disease undergoing colonoscopy were enrolled. The CDAI and SES-CD scores, serum hsCRP and IL-6, CRP and IL-6 genotypes, and fecal calprotectin and lactoferrin were measured.

RESULTS

There were no significant associations between the CDAI and SES-CD scores (Spearman rank correlation coefficient, 0.15) or between the CDAI scores and the serum concentrations of hsCRP and IL-6, or the fecal concentrations of calprotectin and lactoferrin. In contrast, the serum hsCRP and IL-6 concentrations and the fecal calprotectin and lactoferrin concentrations were significantly higher in patients with more severe endoscopic disease activity (SES-CD score > 7 points) (P < .001 for all comparisons). The CRP 717 mutant homozygote and heterozygote status was associated with significantly lower concentrations of hsCRP (P = .02). There was a trend toward higher hsCRP concentrations in the CRP 286 heterozygous adenine mutant-type mutant genotype, but this did not reach statistical significance.

CONCLUSIONS

Serum and fecal biomarker concentrations are associated with endoscopic but not clinical disease activity in patients with Crohn's disease. Stimulated hsCRP concentration is affected significantly by select genetic polymorphisms.

Genetically elevated C-reactive protein and ischemic vascular disease

BACKGROUND

Elevated levels of C-reactive protein (CRP) are associated with increased risks of ischemic heart disease and ischemic cerebrovascular disease. We tested whether this is a causal association.

METHODS

We studied 10,276 persons from a general population cohort, including 1786 in whom ischemic heart disease developed and 741 in whom ischemic cerebrovascular disease developed. We examined another 31,992 persons from a cross-sectional general population study, of whom 2521 had ischemic heart disease and 1483 had ischemic cerebrovascular disease. Finally, we compared 2238 patients with ischemic heart disease with 4474 control subjects and 612 patients with ischemic cerebrovascular disease with 1224 control subjects. We measured levels of high-sensitivity CRP and conducted genotyping for four CRP polymorphisms and two apolipoprotein E polymorphisms.

RESULTS

The risk of ischemic heart disease and ischemic cerebrovascular disease was increased by a factor of 1.6 and 1.3, respectively, in persons who had CRP levels above 3 mg per liter, as compared with persons who had CRP levels below 1 mg per liter. Genotype combinations of the four CRP polymorphisms were associated with an increase in CRP levels of up to 64%, resulting in a theoretically predicted increased risk of up to 32% for ischemic heart disease and up to 25% for ischemic cerebrovascular disease. However, these genotype combinations were not associated with an increased risk of ischemic vascular disease. In contrast, apolipoprotein E genotypes were associated with both elevated cholesterol levels and an increased risk of ischemic heart disease.

CONCLUSIONS

Polymorphisms in the CRP gene are associated with marked increases in CRP levels and thus with a theoretically predicted increase in the risk of ischemic vascular disease. However, these polymorphisms are not in themselves associated with an increased risk of ischemic vascular disease.

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

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

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

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

Maternal and fetal C-reactive protein genotype and first trimester CRP concentrations in maternal plasma

Maternal plasma CRP concentrations in pregnancy are increased over pre-pregnancy values and high concentrations have been associated with adverse obstetrical outcomes. The objective of this study was to explore the relationship between maternal and fetal variation in C-reactive protein (CRP) genotype and maternal plasma CRP concentrations in the first trimester in low risk patients. DNA was extracted from maternal and cord blood of subjects in a prospective observational cohort. Single-nucleotide polymorphism (SNP) selection was made using a linkage disequilibrium bin approach. CRP concentrations were measured in first trimester maternal plasma using an enzyme-linked immunosorbent assay (ELISA) kit. Kruskal-Wallis rank testing was used to analyze genetic and clinical determinants of CRP concentrations. Genotype results were available in 190 mother-baby pairs. There was no significant difference in CRP concentration among maternal or fetal CRP genotypes. Thus, first trimester concentrations of maternal plasma CRP in low risk subjects do not appear to be significantly associated with CRP genotype. Instead, differences in clinical factors probably have more influence on baseline maternal CRP concentrations.

Does high C-reactive protein concentration increase atherosclerosis? The Whitehall II Study

BACKGROUND

C-reactive protein (CRP), a marker of systemic inflammation, is associated with risk of coronary events and sub-clinical measures of atherosclerosis. Evidence in support of this link being causal would include an association robust to adjustments for confounders (multivariable standard regression analysis) and the association of CRP gene polymorphisms with atherosclerosis (Mendelian randomization analysis).

METHODOLOGY/PRINCIPAL FINDINGS

We genotyped 3 tag single nucleotide polymorphisms (SNPs) [+1444T>C (rs1130864); +2303G>A (rs1205) and +4899T>G (rs 3093077)] in the CRP gene and assessed CRP and carotid intima-media thickness (CIMT), a structural marker of atherosclerosis, in 4941 men and women aged 50-74 (mean 61) years (the Whitehall II Study). The 4 major haplotypes from the SNPs were consistently associated with CRP level, but not with other risk factors that might confound the association between CRP and CIMT. CRP, assessed both at mean age 49 and at mean age 61, was associated both with CIMT in age and sex adjusted standard regression analyses and with potential confounding factors. However, the association of CRP with CIMT attenuated to the null with adjustment for confounding factors in both prospective and cross-sectional analyses. When examined using genetic variants as the instrument for serum CRP, there was no inferred association between CRP and CIMT.

CONCLUSIONS/SIGNIFICANCE

Both multivariable standard regression analysis and Mendelian randomization analysis suggest that the association of CRP with carotid atheroma indexed by CIMT may not be causal.