Association of CommonCRPGene Variants with CRP Levels and Cardiovascular Events

C-Reactive Protein Is Not the Driver Factor in Ulcerative Colitis

Purpose: C-reactive protein (CRP) functions as a nonspecific marker in various inflammatory disorders, particularly in evaluating the efficacy of pharmacological treatments in patients with ulcerative colitis. The existing body of evidence does not offer adequate support for the direct implication of CRP in modulating the advancement of ulcerative colitis. Methods: Our study employed a rigorous mouse model. An ulcerative colitis mouse model was established by subjecting CRP-deficient mice to dextran sulfate sodium (DSS) treatment. The phenotype of the mice, which encompassed parameters such as body weight, colon length, and spleen weight, was meticulously evaluated. Additionally, various physiological and biochemical indicators were assessed, including colon histopathology, expression levels of inflammatory factors, and staining of the intestinal mucus layer. Results: The absence of CRP did not significantly affect the phenotype, physiological characteristics, and biochemical indices in a mouse model of ulcerative colitis compared to mice with wild-type CRP. Additionally, eliminating intestinal bacteria flora interference through antibiotic treatment revealed that mice lacking CRP did not demonstrate any notable variations in the ulcerative colitis model. Meanwhile, the survival rate of mice lacking CRP did not exhibit a statistically significant difference compared to wild-type mice. Conclusion: The results of our study suggest that CRP may not directly mediate ulcerative colitis. Instead, it is more likely to be a bystander that is present alongside with elevated inflammatory factors. Further investigation is warranted to determine the precise role of CRP in humans, given the significant limitations associated with the use of mouse models.

The Influence of Balneotherapy Using Salty Sulfide-Hydrogen Sulfide Water on Selected Markers of the Cardiovascular System: A Prospective Study

Background: The sulfide-hydrogen sulfide brine balneotherapy (HSBB), including a combination of dissolved hydrogen sulfide (H2S) gas, inorganic sulfur ions (S2-), and hydrosulfide ions (HS-), is one of the most important and most effective forms of spa treatment in patients with osteoarticular disorders (OADs). Some cardiovascular diseases (CVDs) are often considered to be contraindications to HSBB since the presence of thiol groups may lead to an increased quantity of reactive oxygen species (ROS), which damage the vascular endothelium, and endothelial dysfunction is considered to be the main cause of atherosclerosis. However, there are a number of literature reports suggesting this theory to be false. H2S is a member of the endogenous gaseous transmitter family and, since it is a relatively recent addition, it has the least well-known biological properties. H2S-NO interactions play an important role in oxidative stress in CVDs. The general objective of this study was to assess the cardiovascular safety of HSBB and analyze the effect of HSBB on selected cardiovascular risk markers. Methods: A total of 100 patients at the age of 76.3 (±7.5) years from the Włókniarz Sanatorium in Busko-Zdrój were initially included in the study. The following parameters were assessed: age, sex, height, body weight, body surface area (BSA), body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), heart rate, the diagnosis of OAD that was the indication for balneotherapy, creatinine (CREAT), glomerular filtration rate (GFR), lipid panel, C-reactive protein (CRP), uric acid (UA), and fibrinogen (FIBR) and cardiovascular markers: (cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP). Results: A significant decrease in DBP and a trend towards SBP reduction were observed over the course of the study. A significant decrease was observed in CRP levels decreasing from 2.7 (±3.6) mg/L to 2.06 (±1.91) mg/L, whereas FIBR rose significantly from 2.95 (±0.59) g/L to 3.23 (±1.23) g/L. LDL-C levels decreased slightly, statistically significant, from 129.36 (±40.67) mg/dL to 123.74 (±36.14) mg/dL. HSBB did not affect the levels of evaluated cardiovascular biomarkers, namely NT-proBNP (137.41 (±176.52) pg/mL vs. 142.89 (±182.82) pg/mL; p = 0.477) and cTnT (9.64 (±4.13) vs. 9.65 (±3.91) ng/L; p = 0.948). A multiple regression analysis of pre-balneotherapy and post-balneotherapy values showed cTnT levels to be independently correlated only with CREAT levels and GFR values. None of the assessed parameters independently correlated with the NT-proBNP level. Conclusions: HSBB resulted in a statistically significant improvement in a subclinical pro-inflammatory state. HSBB has a beneficial effect in modifying key cardiovascular risk factors by reducing LDL-C levels and DBP values. HSBB has a neutral effect on cardiovascular ischemia/injury. Despite slightly elevated baseline levels of the biochemical marker of HF (NT-proBNP), HSBB causes no further increase in this marker. The use of HSBB in patients with OAD has either a neutral effect or a potentially beneficial effect on the cardiovascular system, which may constitute grounds for further studies to verify the current cardiovascular contraindications for this form of therapy.

C-Reactive Protein Level and the Genetic Variant rs1130864 in the CRP Gene as Prognostic Factors for 10-Year Cardiovascular Outcome

BACKGROUND

Cardiovascular disease (CVD) is the primary cause of premature death and disability worldwide. There is extensive evidence that inflammation represents an important pathogenetic mechanism in the development and prognosis of CVD. C-reactive protein (CRP) is a potential marker of vascular inflammation and plays a direct role in CVD by promoting vascular inflammation. The objective of this study (ClinTrials.gov identifier: NCT01045070) was to assess the prognostic impact of CRP protein levels and genetic variants of CRP gene events on cardiovascular (CV) outcome (10-year follow-up) in patients suffering from CVD.

METHODS

CVD patients were prospectively included in this study (n = 1002) and followed up (10 years) regarding combined CV endpoint (CV death, death from stroke, myocardial infarction (MI), and stroke/transient ischemic attack (TIA)). CRP protein level (particle-enhanced immunological turbidity test) and genetic variants (rs1130864, rs1417938, rs1800947, rs3093077; polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) after DNA extraction from EDTA-blood) were evaluated.

RESULTS

In survival analyses, increased CRP protein levels of ≥5 mg/L (log-rank test: p < 0.001, Cox regression: p = 0.002, hazard ratio = 1.49) and CT + TT genotype of rs1130864 (log-rank test: p = 0.041; Cox regression: p = 0.103, hazard ratio = 1.21) were associated with a weaker CV prognosis considering combined CV endpoint.

CONCLUSIONS

Elevated CRP level and genetic variant (rs1130864) were proven to provide prognostic value for adverse outcome in CVD patients within the 10-year follow-up period.

Risk Factors and Immunoinflammatory Mechanisms Leading to Atherosclerosis: Focus on the Role of Oral Microbiota Dysbiosis

Cardiovascular diseases (CVD), including myocardial infarction and stroke, are currently the leading cause of morbidity, disability and mortality worldwide. Recently, researchers have focused their attention on the alterations of the gut and oral microbiota, investigating the possible role of their dysbiosis in the pathogenesis and/or progression of CVD. In this regard, it has been shown that endothelial dysfunction, a major feature of CVD, can also be induced by chronic periodontal infection, due to a systemic pro-inflammatory condition, as suggested by increased plasma levels of acute phase proteins, IL-6 and fibrinogen. Moreover, proatherogenic dysfunctions can also be promoted by direct bacterial invasion of the endothelium. This review reports the current evidence about the possible role of oral microbiota dysbiosis and the related immunoinflammatory components in the pathophysiology of atherosclerosis and associated CVD. It is concluded that integration of oral microbiota sampling into clinical practice may result in a more accurate assessment of CV risk in patients and even modify their prognosis.

Association of - 717 A > G (rs2794521) CRP polymorphism with high cardiovascular risk by C-reactive protein in systemic lupus erythematosus patients

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease where genetic factors have been related to SLE susceptibility and disease severity. CRP polymorphisms have been associated with high C-reactive protein (CRP) serum levels, cardiovascular disease (CVD), and high clinical disease activity in SLE patients; however, the evidence is still inconclusive.

OBJECTIVE

This study was aimed to assess the association of the - 717 A > G, - 409 G > A, + 1444 C > T, and + 1846 C > T CRP polymorphisms with genetic susceptibility, clinical disease activity, and CVD risk in Mexican-mestizo SLE patients.

METHODS

A comparative cross-sectional study was conducted on 369 unrelated women: 183 with SLE according to the 1997 SLE-ACR criteria and 186 healthy subjects (HS). The clinical disease activity was assessed by the Mex-SLEDAI score; CRP and lipid profile were quantified by turbidimetry and colorimetric-enzymatic assays, respectively. The CRP polymorphisms genotyping was carried out by allelic discrimination.

RESULTS

SLE patients with - 717 AA genotype had higher CRP serum levels than SLE carriers of AG and GG genotypes (AA = 5 mg/L vs. AG = 3.2 mg/L vs. GG = 2.4 mg/L; p = 0.01), and the AA genotype was associated with high CVD risk by CRP in SLE patients (OR = 3; CI: 1.2-7.6; p < 0.01).

CONCLUSIONS

The - 717 A > G CRP polymorphism is a risk factor for high CRP levels and high CVD risk in Mexican-mestizo SLE patients. Key Points • Cardiovascular disease is one of the major causes of death in SLE patients due to the higher prevalence of traditional and non-traditional cardiovascular risk factors. • C-reactive protein is a liver-derived acute-phase protein suggested as one powerful independent risk predictor factor for cardiovascular disease. • Single nucleotide polymorphisms in CRP have been suggested as genetic susceptibility factors that could modify the SLE pathophysiology outcomes. • Mexican-mestizo SLE patients carrying the -717 A>G CRP AA genotype had 3-fold high cardiovascular disease risk than SLE patients with AG or GG genotypes.

Association of high-sensitivity C-reactive protein and diabetic nephropathy in patients with type 2 diabetes: a Mendelian randomization study

INTRODUCTION

Observational studies support the relationship between C-reactive protein (CRP) level and diabetic nephropathy (DN) in patients with diabetes. The research question regarding whether the relationship between serum high-sensitivity C-reactive protein (hsCRP) level and DN is causal lacks experimental evidence. Therefore, this study aimed to evaluate the causality between hsCRP and DN based on Mendelian randomization (MR) analysis.

RESEARCH DESIGN AND METHODS

A total of 2332 participants with type 2 diabetes from the Taiwan Biobank database was analyzed. Genetic risk scores (GRSs), which comprise four validated CRP loci as two instrumental variables, were calculated as unweighted and weighted scores to evaluate the causal relationship of hsCRP with DN risk. The two-stage regression model was used to estimate OR and 95% CI.

RESULTS

The analyses of the observational study showed that the hsCRP level was significantly associated with DN after multivariate adjustment (adjusted OR 1.15; 95% CI 1.01 to 1.32). Unweighted/weighted GRSs for log-transformed hsCRP satisfied MR assumptions 1 and 3, respectively; that is, a significant association with hsCRP was observed but that with DN was absent (adjusted OR 1.00, 95% CI 0.92 to 1.09; 1.00, 0.72 to 1.39, respectively). The MR analyses demonstrated that a 1-unit increase in the log-transformed genetically predicted hsCRP by unweighted and weighted GRSs was associated with DN, demonstrating ORs of 1.80 (95% CI 1.51 to 2.14) and 1.67 (95% CI 1.40 to 1.98), respectively.

CONCLUSIONS

The current study provided experimental evidence that hsCRP level was causally related to DN. These findings suggest that the elevated hsCRP may be a causal risk factor for DN in patients with type 2 diabetes.

Relationship between CRP gene polymorphisms and ischemic stroke risk: A systematic review and meta-analysis

Ischemic stroke (IS), usually caused due to an abrupt blockage of an artery, is the leading cause of disability and the second leading cause of death worldwide. The association of the C-reactive protein (CRP) gene (s3093059 T/C and rs1205 C/T) polymorphisms and IS susceptibility has been widely studied, but the results remain inconsistent. Our study aimed to assess the association between CRP gene (s3093059 T/C and rs1205 C/T) polymorphisms and IS risk. PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, and WanFang databases were searched up to April 2022 to identify eligible studies. The Newcastle-Ottawa scale (NOS) score was calculated to assess study quality. The odd ratios (ORs) with a 95% confidence interval (CI) were calculated to assess the association between CRP gene (rs3093059 T/C and rs1205 C/T) polymorphisms and IS risk. Eighteen case–control studies with 6339 cases and 29580 controls were identified. We found that CRP (s3093059 T/C and rs1205 C/T) polymorphism was not significantly associated with the risk of IS in any genetic model (recessive model: OR 1.00, 95% CI 0.79–1.26; OR 1.06, 95% CI 0.90–1.25). When stratified analysis by country, genotype method, source of controls, and NOS score, still no statistically significant association was found. Our study indicated that the CRP (rs3093059 T/C and rs1205 C/T) polymorphisms were not associated with the susceptibility to IS.

Pre-diagnostic C-reactive protein concentrations, CRP genetic variation and mortality among individuals with colorectal cancer in Western European populations

BACKGROUND

The role of elevated pre-diagnostic C-reactive protein (CRP) concentrations on mortality in individuals with colorectal cancer (CRC) remains unclear.

METHODS

We investigated the association between pre-diagnostic high-sensitivity CRP concentrations and CRP genetic variation associated with circulating CRP and CRC-specific and all-cause mortality based on data from 1,235 individuals with CRC within the European Prospective Investigation into Cancer and Nutrition cohort using multivariable-adjusted Cox proportional hazards regression.

RESULTS

During a median follow-up of 9.3 years, 455 CRC-specific deaths were recorded, out of 590 deaths from all causes. Pre-diagnostic CRP concentrations were not associated with CRC-specific (hazard ratio, HR highest versus lowest quintile 0.92, 95% confidence interval, CI 0.66, 1.28) or all-cause mortality (HR 0.91, 95% CI 0.68, 1.21). Genetic predisposition to higher CRP (weighted score based on alleles of four CRP SNPs associated with higher circulating CRP) was not significantly associated with CRC-specific mortality (HR per CRP-score unit 0.95, 95% CI 0.86, 1.05) or all-cause mortality (HR 0.98, 95% CI 0.90, 1.07). Among four investigated CRP genetic variants, only SNP rs1205 was significantly associated with CRC-specific (comparing the CT and CC genotypes with TT genotype, HR 0.54, 95% CI 0.35, 0.83 and HR 0.58, 95% CI 0.38, 0.88, respectively) and all-cause mortality (HR 0.58, 95% CI 0.40, 0.85 and 0.64, 95% CI 0.44, 0.92, respectively).

CONCLUSIONS

The results of this prospective cohort study do not support a role of pre-diagnostic CRP concentrations on mortality in individuals with CRC. The observed associations with rs1205 deserve further scientific attention.

Osteoprotegerin and MTHFR gene variations in rheumatoid arthritis: association with disease susceptibility and markers of subclinical atherosclerosis

We aimed to explore whether the rs2073618 variant (G1181C) of the osteoprotegerin (OPG) gene and the methylenetetrahydrofolate reductase (MTHFR) rs1801131 (A1298AC) and rs1801133 (C677T) gene polymorphisms contribute to rheumatoid arthritis (RA) susceptibility and RA related subclinical atherosclerosis. Overall 283 RA patients and 595 healthy controls (HC) were genotyped for common variants of the OPG and MTHFR genes using PCR based assays. Clinical and laboratory parameters were recorded following thorough chart review. Surrogate markers of subclinical atherosclerosis (Carotid/Femoral intima media thickness/plaque formation) along with traditional risk factors for atherosclerosis were assessed in all RA patients and 280HC. Increased prevalence of the CC genotype of the rs2073618 variant was detected in RA patients vs HC (42.4% vs. 33%, p-value: 0.04). RA patients with high serum titers of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies displayed increased prevalence of the CC genotype of the rs2073618 variant of the OPG gene compared to HC (48.6% and 47.5 vs 33.3%, p-values: 0.0029and 0.0077 respectively). Of interest, this genotype turned to be associated with higher carotid IMT scores (0.872 ± 0.264 vs 0.816 ± 0.284, p-value: 0.01) and marginally with higher rates of carotid plaque formation (66% vs 54.1%, p = 0.06). The MTHFR 1298CC genotype was more prevalent only in the anti-CCP positive group compared to HC, with no associations detected with markers of subclinical atherosclerosis, following adjustment for traditional cardiovascular (CVD) risk factors. Reduced rates of carotid/femoral plaque formation were detected among RA patients harboring the MTHFR TT genotype (52.4 vs 72.7, p-value: 0.009, respectively). This association remained significant following adjustment for classical CVD risk factors (OR [95% CI 0.364 [0.173-0.765], p-value: 0.008). Genetic variations of the osteoprotegerin and MTHFR genes seem to increase susceptibility for seropositive RA and potentially contribute to subclinical atherosclerosis linked to RA. Larger studies are needed to confirm these findings.

C-reactive protein in adult Samoans: Population variation and physiological correlates

OBJECTIVES

C-reactive protein (CRP) has been associated with adiposity and cardiometabolic disease risk in many populations but remains remarkably understudied in Pacific Islander populations. Here, we provide the first examination of correlates of CRP in adult Samoans (n = 108, ages 35-55 years) to test the hypotheses that CRP exhibits sex-dependent associations with measures of BMI, adiposity, and cardiometabolic disease risks.

METHODS

We analyzed associations between measures of adiposity (total fat mass, visceral fat mass, percent total body fat), body mass index (BMI), cardiometabolic risks, behaviors, demographics, and CRP. Unadjusted analyses of CRP were undertaken using Pearson's pairwise, and Spearman's rank correlations; one-way analysis of variance and Kruskal-Wallis tests assessed variables by CRP quartiles. Adjusted analyses of CRP correlates were examined using generalized linear regression.

RESULTS

Serum CRP ranged from 0.08 to 13.3 mg/L (median 1.4 mg/L) and varied significantly by sex t (108) = -2.47, p = .015. CRP was weakly to moderately associated with measures of adiposity and BMI (r and ρ ranged between 0.25 and 0.50, p < .05) and some cardiometabolic markers (including HbA1c, fasting insulin, and insulin resistance). CRP was significantly associated with percent body fat in women and men, adjusting for other variables.

CONCLUSIONS

These data are among the first to demonstrate CRP correlates in a sample of adult Samoans. CRP differed by sex and was associated with BMI, adiposity, and some cardiometabolic risk markers. These data align with findings in other populations.

How Are Epigenetic Modifications Related to Cardiovascular Disease in Older Adults?

The rate of aging has increased globally during recent decades and has led to a rising burden of age-related diseases such as cardiovascular disease (CVD). At the molecular level, epigenetic modifications have been shown recently to alter gene expression during the life course and impair cellular function. In this regard, several CVD risk factors, such as lifestyle and environmental factors, have emerged as key factors in epigenetic modifications within the cardiovascular system. In this study, we attempted to summarized recent evidence related to epigenetic modification, inflammation response, and CVD in older adults as well as the effect of lifestyle modification as a preventive strategy in this age group. Recent evidence showed that lifestyle and environmental factors may affect epigenetic mechanisms, such as DNA methylation, histone acetylation, and miRNA expression. Several substances or nutrients such as selenium, magnesium, curcumin, and caffeine (present in coffee and some teas) could regulate epigenetics. Similarly, physical inactivity, alcohol consumption, air pollutants, psychological stress, and shift working are well-known modifiers of epigenetic patterns. Understanding the exact ways that lifestyle and environmental factors could affect the expression of genes could help to influence the time of incidence and severity of aging-associated diseases. This review highlighted that a healthy lifestyle throughout the life course, such as a healthy diet rich in fibers, vitamins, and essential elements, and specific fatty acids, adequate physical activity and sleep, smoking cessation, and stress control, could be useful tools in preventing epigenetic changes that lead to impaired cardiovascular function.

Genetic ablation of C-reactive protein gene confers resistance to obesity and insulin resistance in rats

AIMS/HYPOTHESIS

Besides serving as a traditional inflammatory marker, C-reactive protein (CRP) is closely associated with the development of obesity, diabetes and cardiovascular diseases as a metabolic and inflammatory marker. We hypothesise that CRP protein directly participates in the regulation of energy and glucose metabolism rather than just being a surrogate marker, and that genetic deficiency of CRP will lead to resistance to obesity and insulin resistance.

METHODS

Crp gene deletion was achieved by transcription activator-like effector nuclease (TALEN) technology in rats. The Crp knockout animals were placed on either a standard chow diet or a high-fat diet. Phenotypic changes in body weight, glucose metabolism, insulin sensitivity, energy expenditure and inflammation condition were examined. The central impact of CRP deficiency on leptin and insulin hypothalamic signalling, as well as glucose homeostasis, were examined via intracerebral ventricular delivery of leptin and CRP plus glucose clamp studies in the wild-type and Crp knockout rats.

RESULTS

CRP deficiency led to a significant reduction in weight gain and food intake, elevated energy expenditure and improved insulin sensitivity after exposure to high-fat diet. Glucose clamp studies revealed enhanced hepatic insulin signalling and actions. Deficiency of CRP enhanced and prolonged the weight-reducing effect of central injected leptin and promoted the central and peripheral roles of leptin. By contrast, reinstatement of CRP into the hypothalamus of the knockout rats attenuated the effects of central leptin signalling on insulin sensitivity and peripheral glucose metabolism.

CONCLUSIONS/INTERPRETATION

This study represents the first line of genetic evidence that CRP is not merely a surrogate blood marker for inflammation and metabolic syndromes but directly regulates energy balance, body weight, insulin sensitivity and glucose homeostasis through direct regulation of leptin's central effect and hypothalamic signalling.

Association of CRP genetic variation with symptomatology, cognitive function, and circulating proinflammatory markers in civilian women with PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) has been associated with increased inflammation. C-reactive protein (CRP) is a marker of systemic inflammation, and recently, single nucleotide polymorphisms (SNPs) in the CRP gene have been associated with increased blood CRP protein levels and illness severity in PTSD patients. However, the mechanism by which the CRP SNPs are involved in PTSD remains unclear. Here we investigated the association of CRP genetic variation with blood proinflammatory protein levels, symptomatology, and cognitive function, and further explored the moderating effect of childhood maltreatment history, in adult patients with PTSD.

METHODS

Fifty-seven Japanese civilian women with PTSD and 73 healthy control women were enrolled. Three SNPs in the CRP gene, namely rs2794520, rs1130864, and rs3093059, were genotyped, and analyses focused on rs2794520 (T/C). Serum levels of high-sensitivity CRP (hsCRP), high-sensitivity tumor necrosis factor-α (hsTNF-α), and interleukin-6 were measured. PTSD symptoms were evaluated by the Posttraumatic Diagnostic Scale. Cognitive function was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status. Childhood maltreatment history was assessed by the Childhood Trauma Questionnaire.

RESULTS

Patients with the rs2794520 CC/CT genotype, compared to those with the TT genotype, showed significantly higher levels of hsCRP (p=0.009) and hsTNF-α (p=0.001), more severe PTSD symptoms (p=0.036), and poorer cognitive function (p=0.018). A two-way analysis of variance revealed a significant genotype-by-maltreatment interaction for more severe PTSD avoidance symptom (p=0.012).

LIMITATIONS

The relatively small sample size limited our findings.

CONCLUSIONS

These findings may provide an insight into the etiology of PTSD from the inflammatory perspective.

The Genetic Variants -717T>C (rs2794521), 1444G>A (rs1130864), and 1846 C > T (rs1205) of CRP Gene, Their Haplotypes, and Their Association with Serum CRP Levels, Acute Coronary Syndrome, and Diabetes in Patients from Western Mexico

Background: C-reactive protein (CRP) is involved in inflammatory pathways that are associated with the onset and progression of type 2 diabetes mellitus (T2DM) as well as an increased risk of an acute coronary syndrome (ACS). This research aimed to evaluate the potential association of the genetic variants -717T>C, 1444G>A, and 1846 C > T of CRP gene on CRP levels, ACS, and T2DM in participants from Western Mexico. Methods: Six hundred three participants were studied: (1) control group (CG); (2) ACS participants classified as unstable angina (UA), myocardial infarction without ST-segment elevation (NSTEMI), and myocardial infarction with ST-segment elevation (STEMI); (3) T2DM Participants; and (4) ACS plus T2DM participants (ACS+T2DM). Genetic variants were genotyped using allelic discrimination with TaqMan^® probes, and high-sensitivity CRP (hs-CRP) was measured by Turbidimetry. Results: TAC haplotype frequency was significantly higher in ACS+T2DM versus CG and versus ACS participants (odds ratio [OR] = 2.774, P = 0.017 and OR = 3.479, P = 0.020, respectively). hs-CRP levels were especially higher for ACS and for ACS+T2DM participants with respect to CG and T2DM (with P < 0.0001). We observed higher hs-CRP levels in NSTEMI and STEMI versus UA in ACS scenario (P = 0.001, P = 0.027, respectively) and for ACS+T2DM scenario (P = 0.0001, P = 0.002, respectively). Conclusion: hs-CRP level fluctuations are related to the presence of T2DM and the presence and severity of ACS. Very high levels (>10 mg/L) are a risk marker of cardiovascular complications. Our results demonstrate a possible relationship between TAC haplotype and an increased risk for T2DM and ACS.

Atherosclerosis and inflammation. New therapeutic approaches

The recognition of atherogenesis as an active process rather than a passive cholesterol storage disease has underlined key inflammatory mechanisms. Hence, innate and adaptive immune responses play an important role in the onset and progression of atherosclerosis. More recently, some clinical studies were designed to address the impact of anti-inflammatory intervention strategies in reducing risk of cardiovascular disease beyond the management of classic risk factors. Therefore, we review first the pathophysiological contribution of inflammation to atherosclerosis and the effect of lipid-lowering drugs on inflammatory biomarkers. Next, we address the effect of classic anti-inflammatory drugs, pharmacological therapies targeting specific inflammatory mediators and vaccines in cardiovascular prevention.

C-reactive protein concentration in bipolar disorder: association with genetic variants

Background

Several recent studies have investigated the role of C-reactive protein (CRP) in bipolar disorder (BD), but few studies have directly investigated the interaction between CRP genetic variants and peripheral CRP concentration across different phases of BD. In this study, we aimed to replicate previous findings that demonstrated altered CRP levels in BD, and to investigate whether there is an association of peripheral protein expression with genetic variants in the CRP gene.

Methods

221 patients were included in the study, of which 183 (all episodes, 46 not medicated, 174 medicated) were genotyped for CRP single-nucleotide polymorphisms (SNPs) shown to influence peripheral CRP protein expression (rs1800947, rs2808630, rs1417938, rs1205).

Results

There were no differences in CRP levels associated with the genotypes, only regarding the rs1205 SNP there were significantly different CRP protein expression between the genotypes when taking body mass index, age, BD polarity, subtype and leukocyte number into account. However, we could show significantly elevated CRP protein expression in manic patients compared to euthymic and depressed patients, independent from genotype. Medication was found to have no effect on CRP protein expression.

Conclusions

These results indicate that low grade inflammation might play a role in mania and might be rather a state than a trait marker of bipolar disorder.

Association of plasma C-reactive protein with ischaemic stroke: a Mendelian randomization study

BACKGROUND AND PURPOSE

Elevated C-reactive protein (CRP) is associated with an increased risk of ischaemic stroke (IS). However, the causality of this association is uncertain. The aim is to investigate whether genetically raised plasma CRP concentration levels are associated with IS on the basis of the Mendelian randomization method.

METHODS

Based on the National Center for Biotechnology Information single nucleotide polymorphism (SNP) database, the Chinese online genetic database as well as previously published studies, four CRP-associated SNP alleles (rs1130864, rs1205, rs876537 and rs3093059) with minor allele frequency ≥0.15 were selected and the concentration levels of CRP were measured in 378 first-ever IS patients and 613 healthy controls.

RESULTS

Three SNPs were chosen and used as instrumental variables. The adjusted odds ratios (ORs) [95% confidence interval (95% CI)] of IS per addition of the modelled allele were 1.07 (0.79-1.45) for rs876537, 0.99 (0.73-1.35) for rs1205 and 1.08 (0.71-1.65) for rs3093059. The OR (95% CI) of IS for plasma CRP ≥2.0 mg/l was 2.19 (1.06-4.53) compared with <2.0 mg/l. The adjusted OR (95% CI) of IS per genetically predicted 10% higher CRP concentration, based on the three SNPs as the instruments, was 1.02 (0.94-1.11). Furthermore, similar results were obtained with adjusted ORs (95% CI) of 1.00 (0.88-1.13) and 1.04 (0.93-1.16), respectively, for large-artery atherosclerosis and small-artery occlusion per genetically predicted 10% higher CRP concentration.

CONCLUSIONS

This Mendelian randomization study provides no clear support that elevated CRP concentration is causally associated with the risk of IS.

The relationship between CRP gene polymorphism (rs2794521, rs3091244), ASDAS-CRP and ASDAS-ESR in ankylosing spondylitis

Background: We aimed to investigate the haplotypes and alleles of two variants (rs2794521 and rs3091244) in AS patients and to examine their relationship with ASDAS-CRP and ASDAS-ESR values.Methods: We evaluated 160 AS patients diagnosed according to the ASAS criteria. ASDAS-CRP and ASDAS-ESR values were calculated. ESR and CRP were examined. The restriction fragment length polymorphism (RFLP) method was used for detecting the rs2794521 and rs3091244 regions on the CRP gene.Results: As a result of the evaluation of rs2794521 gene polymorphism using PCR, TT, TC and CC genotypes were observed in 90, 81 and 9 individuals, respectively. As a result of the evaluation of rs3091244 gene polymorphism, CC, AC and TT genotypes were observed in 104, 51 and 5 individuals, respectively. T allele and C allele were found in rs2794521 gene by 75% and 25%, respectively. In addition, T allele, C allele and A allele were found in rs3091244 gene by 80%, 17% and 3%, respectively. With the help of regression equation, ASDAS-CRP level was 0.34 units higher in cases with rs3091244 C allele than cases without rs3091244 C alleles.Conclusion: CRP rs3091244 C allele may be associated with the increased relative risk for ASDAS-CRP.

CRP Gene Polymorphism and Their Risk Association With Type 2 Diabetes Mellitus

BACKGROUND:

C-reactive protein (CRP) is an inflammatory marker associated with T2DM, obesity, insulin resistance, and cardiovascular disease.

AIM:

The present study evaluates the association of CRP +1059 G/C polymorphism of the CRP gene in 100 T2D cases and 100 healthy controls.

METHODS:

Present study was done by allele specific PCR method to study the CRP gene polymorphism in study subjects.

RESULTS:

Study found that CRP (+1059 G/C) genotype distribution among case and controls was found to be significant (p=0.001), Higher CRP C allele frequency (0.16) was observed compared to controls (0.04). CRP +1059 GC and CC had 2.72 (1.12-6.61), 20.56 (1.16-362.1) risk for T2D. It has been observed, HTN, Obesity, Smoking and alcoholism was found to be associated with increased risk of T2D, and a significant difference was observed in biochemical parameters.

CONCLUSION:

Study concluded that CRP gene polymorphism was found to be associated with risk of Type 2 Diabetes and risk was linked with heterozygosity and mutant homozygosity. Hypertension, Obesity, Smoking and alcoholism increases the risk of occurrence of Type 2 Diabetes.

Genetic Variation Affects C-Reactive Protein Elevations in Crohn's Disease

BACKGROUND

C-reactive protein (CRP) is a serum marker that is used to measure disease activity in Crohn's disease (CD). However, a subset of CD patients have normal CRP during flares. In rheumatoid arthritis and lupus, genetic variants can restrict CRP elevations during flares. This study sought to determine if common CRP genetic variants affect CRP values during active CD.

METHODS

Subjects with CD who participated in the Partners HealthCare BioBank were genotyped for 5 common CRP genetic variants (rs2794520, rs3122012, rs3093077, rs2808635, and rs1800947). Medical records were reviewed to determine disease activity and the highest CRP value during active CD. CRP values during active infection or malignancy at the time of the test were excluded. CRP values were compared by genotype using the Mann-Whitney test.

RESULTS

The study included 199 subjects with active CD (21 to 86 years of age). Subjects with the rs2794520 TT genotype had a lower CRP than subjects with the CC genotype (58.3 mg/L vs 28.4 mg/L, P = 0.008). Subjects with the rs1800947 CG genotype had a lower CRP than those with the CC genotype (54.3 mg/L vs 22.4 mg/L, P < 0.0001); 41.6% of TT subjects had a normal CRP compared with 24.1% of CT subjects and 16.5% of CC subjects (P = 0.041).

CONCLUSIONS

This study demonstrates that rs2794520 and rs1800947 are associated with a restriction of CRP elevations during active CD. While CRP is typically a reliable biomarker in CD, there is a subset of CD patients with a genetically determined restriction of CRP in whom other disease markers should be utilized.

The Clinical Significance and Potential Role of C-Reactive Protein in Chronic Inflammatory and Neurodegenerative Diseases

C-reactive protein (CRP) is an acute-phase protein synthesized by hepatocytes in response to pro-inflammatory cytokines during inflammatory/infectious processes. CRP exists in conformationally distinct forms such as the native pentameric CRP and monomeric CRP (mCRP) and may bind to distinct receptors and lipid rafts and exhibit different functional properties. It is known as a biomarker of acute inflammation, but many large-scale prospective studies demonstrate that CRP is also known to be associated with chronic inflammation. This review is focused on discussing the clinical significance of CRP in chronic inflammatory and neurodegenerative diseases, such as cardiovascular disease, type 2 diabetes mellitus, age-related macular degeneration, hemorrhagic stroke, Alzheimer’s disease, and Parkinson’s disease, including recent advances on the implication of CRP and its forms specifically on the pathogenesis of these diseases. Overall, we highlight the advances in these areas that may be translated into promising measures for the diagnosis and treatment of inflammatory diseases.

Association between CRP genetic diversity and bipolar disorder comorbid complications

Background

Chronic low-grade inflammation is believed to contribute, at least in a subset of patients, to the development of bipolar disorder (BD). In this context, the most investigated biological marker is the acute phase response molecule, C-reactive protein (CRP). While the genetic diversity of CRP was amply studied in various pathological settings, little is known in BD.

Methods

568 BD patients along with 163 healthy controls (HC) were genotyped for the following single-nucleotide polymorphisms (SNPs) on the CRP gene: intron rs1417938 (+ 29) T/A, 3′-UTR rs1130864 (+ 1444) G/A, and downstream rs1205 (+ 1846) (C/T). The statistical analysis was performed using Chi-square testing and consisted of comparisons of allele/genotype frequencies between patients and controls and within patient sub-groups according to BD clinical phenotypes and the presence of thyroid disorders.

Results

We found that the frequencies of the studied SNPs were similar in BD and HC groups. However, the CRP rs1130864 A allele carrier state was significantly more frequent: (i) in BD patients with thyroid disorders than in those without (pc = 0.046), especially among females (pc = 0.01) and independently of lithium treatment, (ii) in BD patients with rapid cycling than in those without (pc = 0.004).

Conclusions

Overall, our findings suggest the possibility that CRP genetic diversity may contribute to the development of auto-immune comorbid disorders and rapid cycling, both proxy of BD severity. Such findings, if replicated, may allow to predict complex clinical presentations of the disease, a possible step towards precision medicine in psychiatry.

Immunogenetics of prostate cancer: a still unexplored field of study

The immune system is a double-edged sword with regard to the prostate cancer (PCa) battle. Immunogenetics, the study of the potential role of immune-related polymorphisms, is taking its first steps in the treatment of this malignancy. This review summarizes the most recent papers addressing the potential of immunogenetics in PCa, reporting immune-related polymorphisms associated with tumor aggressiveness, treatment toxicity and patients' prognosis. With some peculiarities, RNASEL, IL-6, IL-10, IL-1β and MMP7 have arisen as the most significant biomarkers in PCa treatment and management, having a potential clinical role. Validation prospective clinical studies are required to translate immunogenetics into precision treatment of PCa.

C-reactive protein levels and genetic variants of CRP as prognostic markers for combined cardiovascular endpoint (cardiovascular death, death from stroke, myocardial infarction, and stroke/TIA)

BACKGROUND

The aim of this analysis was to evaluate the importance of C-reactive protein levels and genetic variants of CRP as prognostic markers for further cardiovascular (CV) events (3-year follow-up) in a cohort of in-patients with cardiovascular disease (CVD) patients.

METHODS AND RESULTS

Patients with angiographic proven CVD (n=939) were prospectively included. The three-year CV outcome of the patients was evaluated considering the predefined, combined endpoint (CV death, death from stroke, myocardial infarction, and stroke/TIA). Polymorphisms rs1800947, rs1417938, rs1130864, rs3093077 were analysed. In Kaplan-Meier survival curve and Cox regression increased CRP levels of ⩾5mg/l (log-rank test: p=0.001, Cox regression: hazard ratio=1.77, 95% CI: 1.2-2.7) and the GG genotype of rs1800947 (log-rank test: p=0.01, Cox regression: hazard ratio=1.99, 95% CI: 1.1-3.6) were associated with the incidence of the combined endpoint.

CONCLUSIONS

Both a CRP level ⩾5mg/l and SNP rs1800947 of the CRP gene were independent risk factors for further adverse CV events among patients with CVD within three years follow-up.

Evaluation of inflammation during fixed orthodontic treatment

OBJECTIVE

The aim of this study was to assess effects of fixed orthodontic therapy on high-sensitivity C-reactive protein (hs-CRP) level, CBC parameters and levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), urea, creatinine, sodium (Na), potassium (K), calcium (Ca), total protein (TP), and albumin (Alb).

DESIGN

Blood samples (7ml) were drawn at baseline, on days 1 and 7, and three months after placement of braces in the study group, while only one blood sample was drawn at baseline in the control group. Serum hs-CRP levels were measured by nephelometric method. Friedman two-way variance analysis was used to assess values with skewed distribution obtained at baseline, on days 1 and 7, in the third month. Wilcoxon rank sign test was performed if median values were unequal.

RESULTS

During measurement periods, there were significant increases in hs-CRP level, WBC count and neutrophil count while a significant decrease in Na level (p<0.05). K level was significantly decreased on the day 1. No significant differences were detected in other biochemical parameters evaluated.

CONCLUSION

Elevation in serum hs-CRP levels and neutrophil: lymphocyte ratio within first 3 months indicates that a systemic immune response develops against therapy in patients undergoing fixed orthodontic therapy.

Ischemic Stroke and Six Genetic Variants in CRP, EPHX2, FGA, and NOTCH3 Genes: A Meta-Analysis

BACKGROUND

Ischemic stroke (IS) is a leading cause of death and disability worldwide. As genetic heritability for IS is estimated at about 35%-40%, the identification of genetic variants associated with IS risk is of great importance. The main objective of this study was to carry out a meta-analysis for polymorphisms in CRP, EPHX2, FGA, and NOTCH3 genes and the risk for IS.

METHODS

Literature search for 6 candidate polymorphisms and IS was conducted using HuGE Navigator, PubMed, and Google Scholar databases. Meta-Analyst program was used to calculate pooled odds ratios (ORs) with a random effects model.

RESULTS

Twenty-five published studies for 6 candidate polymorphisms were included: CRP-rs1800947 (5 studies), CRP-rs1205 (3 studies), EPHX2-rs751141 (5 studies), FGA-rs6050 (6 studies), NOTCH3-rs3815188 (3 studies), and NOTCH3-rs1043994 (3 studies), for a total number of 7,825 IS cases and 56,532 control subjects. We did not find significant pooled ORs (P values > .05) for any of the genetic variants evaluated in this work.

CONCLUSIONS

Our meta-analysis results did not show significant associations between these 6 polymorphisms in 4 candidate genes and IS, despite the functional role of some of these single nucleotide polymorphisms (e.g., rs6050 in FGA gene). Future studies are needed to identify additional main genetic risk factors for IS in different populations.

Joint effect of gene-physical activity and the interactions among CRP, TNF-α, and LTA polymorphisms on serum CRP, TNF-α levels, and handgrip strength in community-dwelling elders in Taiwan - TCHS-E

This study assesses interactions of tumor necrosis factor α (TNF-α) gene polymorphisms with C-reactive protein (CRP) or lymphotoxin α (LTA) gene on serum CRP and TNF-α levels and handgrip strength. Eleven single nucleotide polymorphisms (SNPs), including rs2794520, rs1205, rs1130864, rs1800947, and rs3093059 in CRP; rs1799964, rs1800629, and rs3093662 in TNF-α; and rs2239704, rs909253, and rs1041981 in LTA, were genotyped in 472 unrelated elders (mean age 73.8 years). Among elders with TNF-α rs1799964 AA genotype, adjusted mean difference for handgrip strength decreased by -2.60 (-4.82, -0.38) and -2.51 kg (-4.75, -0.28) for LTA rs909253 and rs1041981 in women and by -2.39 kg (-3.98, -0.81) for CRP rs3093059 in men. Among elders with TNF-α rs1799964 AA genotype, adjusted mean ratios for hs-CRP levels increased by 2.32 (1.38, 3.90) and 2.27 (1.35, 3.84) for both CRP rs909253 and rs1041981 in women. The A-A-C LTA haplotype was associated with TNF-α levels that were 1.55 times higher than those of the C-G-A haplotype (P = 0.005). The joint effects of SNPs (the rs1800947 or rs3093059 of CRP, rs1799964 or rs1800629 of TNF-α, and rs909253 or rs1041981 of LTA) and physical inactivity appeared to have greater magnitude of decreased handgrip strength than main effects of these SNPs and physical inactivity. Our data showed that significant interactions of TNF-αrs1799964 and LTA rs909253 were observed. Moreover, joint effects of these CRP, TNF-α, and LTA risk alleles with physical inactivity in elders were observed, suggesting that physical activity may modulate effects of genotypes on handgrip strength.

Elevated C-reactive protein and late-onset bipolar disorder in 78 809 individuals from the general population

BACKGROUND

No prospective studies have examined the role of C-reactive protein (CRP) in late-onset bipolar disorder.

AIMS

We tested the hypothesis that elevated levels of CRP are associated cross-sectionally and prospectively with late-onset bipolar disorder, and that such an association possibly is causal.

METHOD

We performed cross-sectional and prospective analyses with a median follow-up time of 5.9 years (interquartile range: 4.4-7.6) in 78 809 individuals from the general population, and used genetic variants influencing CRP levels to perform a Mendelian randomisation study.

RESULTS

Elevated levels of CRP were associated both cross-sectionally and prospectively with late-onset bipolar disorder. When CRP was on a continuous scale, a doubling in CRP yielded an observational odds ratio for late-onset bipolar disorder of 1.28 (1.08-1.52) with a corresponding causal odds ratio of 4.66 (0.89-24.3).

CONCLUSION

Elevated CRP is associated with increased risk of late-onset bipolar disorder in the general population which was supported by the genetic analysis.

Increased Baseline C-Reactive Protein Concentrations Are Associated with Increased Risk of Infections: Results from 2 Large Danish Population Cohorts

BACKGROUND

The acute-phase reactant C-reactive protein (CRP) increases rapidly during an infection. We tested the hypothesis that chronic low-level increases in CRP are associated with an increased risk of infectious disease.

METHODS

We studied 9660 individuals from a prospective general population cohort, including 3592 in whom infectious disease developed, and another 60 896 individuals from a cross-sectional general population study, of whom 13 332 developed infectious disease; 55% were women, and the mean age was 57 years. Hospital diagnoses of infections in 1977-2010 were based on International Classification of Diseases-coded discharge records from the national Danish Patient Registry. We measured CRP concentrations and conducted genotyping for 4 CRP polymorphisms that increase CRP. Individuals with CRP >10 mg/L were excluded because of possible ongoing infection at the time of testing.

RESULTS

Individuals with CRP >3 mg/L had 1.2 and 1.7 times increased risk of infectious disease, in the prospective general population cohort and the cross-sectional general population study, respectively, compared with individuals with CRP <1 mg/L. In the combined populations, individuals in the highest CRP tertile (compared with the lowest) had an increased risk of bacterial diseases (hazard ratio 1.7, 95% CI 1.6-1.8), but not viral, mycosis, and parasitic diseases. The increased risk was mainly carried by pneumonia, sepsis, and particularly gram-negative infections. None of the genotype combinations examined conferred an increased risk of infectious disease.

CONCLUSIONS

Chronic low-level CRP increases were associated with increased risk of bacterial infections, gram-negative infections in particular. Genotypes associated with increases in CRP were not associated with increased risk of infection.

Association of the C-Reactive Protein Gene (CRP) rs1205 C>T Polymorphism with Aortic Valve Calcification in Patients with Aortic Stenosis

Elevation in C-reactive protein (CRP) levels have been shown in patients with aortic valve stenosis (AS). Minor allele of the CRP gene (CRP) rs1205 C>T polymorphism has been associated with lower plasma CRP concentrations in cohorts of healthy and atherosclerotic patients. Considering the existing similarities between atherosclerosis and AS, we examined the effect of CRP rs1205 C>T polymorphism on the AS severity. Three hundred consecutive Caucasian patients diagnosed with AS were genotyped for the rs1205 C>T polymorphism using the TaqMan assay. Severity of the AS was assessed using transthoracic echocardiography. The degree of calcification was analyzed semi-quantitatively. Carriers of the rs1205 T allele were characterized by elevated serum CRP levels (2.53 (1.51-3.96) vs. 1.68 (0.98-2.90) mg/L, p<0.001) and a higher proportion of the severe aortic valve calcification (70.4% vs. 55.1%, p=0.01) compared with major homozygotes. The effect of CRP rs1205 polymorphism on CRP levels is opposite in AS-affected than in unaffected subjects, suggesting existence of a disease-specific molecular regulatory mechanism. Furthermore, rs1205 variant allele predisposes to larger aortic valve calcification, potentially being a novel genetic risk marker of disease progression.

Genetic Association Studies Reporting on Variants in the C-Reactive Protein Gene and Coronary Artery Disease: A Meta-Analysis

C-reactive protein (CRP) is a commonly used inflammatory marker and elevated CRP levels are shown to increase the risk of coronary artery disease (CAD). Sequence variations in the CRP gene believed to influence the protein levels have been extensively investigated in CAD community. Most of the published studies, however, have reported mixed findings. The objective of the present study was to examine the associations of CRP variants (+942G>C, -717A>G, +1444C>T) with genetic risk of CAD by use of a meta-analysis.The human case-control studies were identified through online search, hand search, and contacting the authors of original articles. We performed both random-effect and fixed-effect meta-analysis to estimate CAD risk (odds ratios, OR). This analysis combined 16 studies in total. We found +942G>C was not associated with CAD risk when all data were pooled together, nor did we find a significant association in subgroup analyses. Meta-analysis of +1444C>T studies showed a similar trend. However, a borderline association with CAD risk was revealed for -717A>G (random-effect: OR = 0.53, 95% CI = 0.28-1.00 for the homozygous model; random-effect: OR = 0.51, 95% CI = 0.26-1.00 for the recessive model).These data suggest that the CRP gene variants examined may not modulate CAD risk.

Evaluation of Hs-CRP levels and interleukin 18 (-137G/C) promoter polymorphism in risk prediction of coronary artery disease in first degree relatives

BACKGROUND

Coronary Artery Disease (CAD) is clearly a multifactorial disease that develops from childhood and ultimately leads to death. Several reports revealed having a First Degree Relatives (FDRS) with premature CAD is a significant autonomous risk factor for CAD development. C - reactive protein (CRP) is a member of the pentraxin family and is the most widely studied proinflammatory biomarker. IL-18 is a pleiotrophic and proinflammatory cytokine which is produced mainly by macrophages and plays an important role in the inflammatory cascade.

METHODS AND RESULTS

Hs-CRP levels were estimated by ELISA and Genotyping of IL-18 gene variant located on promoter -137 (G/C) by Allele specific PCR in blood samples of 300 CAD patients and 300 controls and 100 FDRS. Promoter Binding sites and Protein interacting partners were identified by Alibaba 2.1 and Genemania online tools respectively. Hs-CRP levels were significantly high in CAD patients followed by FDRS when compared to controls. In IL-18 -137 (G/C) polymorphism homozygous GG is significantly associated with occurrence of CAD and Hs-CRP levels were significantly higher in GG genotype subjects when compared to GC and CC. IL-18 was found to be interacting with 100 protein interactants.

CONCLUSION

Our results indicate that Hs-CRP levels and IL-18-137(G/C) polymorphism may help to identify risk of future events of CAD in asymptomatic healthy FDRS.

Association of CRP genetic variants with blood concentrations of C-reactive protein and colorectal cancer risk

High blood concentrations of C-reactive protein (CRP) have been associated with elevated risk of colorectal cancer in several prospective studies including the European Prospective Investigation into Cancer and Nutrition (EPIC), but it is unknown whether these observations reflect a causal relationship. We aimed to investigate whether CRP genetic variants associated with lifelong higher CRP concentrations translate into higher colorectal cancer risk. We conducted a prospective nested case-control study within EPIC including 727 cases diagnosed between 1992 and 2003 and 727 matched controls selected according to an incidence-density sampling protocol. Baseline CRP concentrations were measured in plasma samples by a high sensitivity assay. Tagging single nucleotide polymorphisms (SNPs) in the CRP gene (rs1205, rs1800947, rs1130864, rs2808630, rs3093077) were identified via HapMap. The causal effect of CRP on colorectal cancer risk was examined in a Mendelian Randomization approach utilizing multiple CRP genetic variants as instrumental variables. The SNPs rs1205, rs1800947, rs1130864 and rs3093077 were significantly associated with CRP concentrations and were incorporated in a CRP allele score which was associated with 13% higher CRP concentrations per allele count (95% confidence interval 8-19%). Using the CRP-score as instrumental variable, genetically twofold higher CRP concentrations were associated with higher risk of colorectal cancer (odds ratio 1.74, 95% confidence interval 1.06-2.85). Similar observations were made using alternative definitions of instrumental variables. Our findings give support to the hypothesis that elevated circulating CRP may play a direct role in the etiology of colorectal cancer.

CRP genotype and haplotype associations with serum C-reactive protein level and DAS28 in untreated early rheumatoid arthritis patients

INTRODUCTION

Single-nucleotide polymorphisms (SNPs) in the CRP gene are implicated in the regulation of the constitutional C-reactive protein (CRP) expression and its response to proinflammatory stimuli. Previous reports suggest that these effects may have an impact on clinical decision-making tools based on CRP, such as the Disease Activity Score in 28 joints (DAS28). We aimed to investigate the possible association between seven CRP SNPs, their haplotypes and the serum levels of CRP, as well as DAS28 scores, in two cohorts of untreated active early rheumatoid arthritis (RA) patients followed during their initial treatment.

METHODS

Overall, 315 patients with RA from two randomized controlled trials (the CIMESTRA and OPERA trials) who were naïve to disease-modifying antirheumatic drugs and steroids with disease durations less than 6 months were included. Seven CRP SNPs were investigated: rs11265257, rs1130864, rs1205, rs1800947, rs2808632, rs3093077 and rs876538. The genotype and haplotype associations with CRP and DAS28 levels were evaluated using linear regression analysis adjusted for age, sex and treatment.

RESULTS

The minor allele of rs1205 C > T was associated with decreased CRP levels at baseline (P = 0.03), with the TT genotype having a 50% reduction in CRP from 16.7 to 8.4 mg/L (P = 0.005) compared to homozygosity of the major allele, but no association was observed at year 1 (P = 0.38). The common H2 haplotype, characterized by the T allele of rs1205, was associated with a 26% reduction in CRP at baseline (P = 0.043), although no effect was observed at year 1 (P = 0.466). No other SNP or haplotype was associated with CRP at baseline or at year 1 (P ≥ 0.09). We observed no associations between SNPs or haplotypes and DAS28 scores at baseline or at year 1 (P ≥ 0.10).

CONCLUSION

CRP genotype and haplotype were only marginally associated with serum CRP levels and had no association with the DAS28 score. This study shows that DAS28, the core parameter for inflammatory activity in RA, can be used for clinical decision-making without adjustment for CRP gene variants.

TRIAL REGISTRATION

The OPERA study is registered at Clinicaltrials.gov (NCT00660647). The CIMESTRA study is not listed in a clinical trials registry, because patients were included between October 1999 and October 2002.

Association of serum C-reactive protein levels with lupus disease activity in the absence of measurable interferon-α and a C-reactive protein gene variant

OBJECTIVE

The type I interferon (IFN) system is important in the pathogenesis of systemic lupus erythematosus (SLE). We previously demonstrated an inhibitory effect of IFNα on interleukin-6 (IL-6)-induced C-reactive protein (CRP) in vitro, hypothetically explaining the poor correlation between disease activity and CRP levels in SLE. This study was undertaken to investigate disease activity, IL-6 levels, and CRP levels in relation to a CRP gene polymorphism and IFNα.

METHODS

Sera from 155 SLE patients and 100 controls were analyzed for CRP. Patients were genotyped for a CRP single-nucleotide polymorphism (rs1205) associated with low CRP levels. Serum IFNα and IL-6 levels were quantified by immunoassays. Clinical disease activity was assessed using the SLE Disease Activity Index 2000 (SLEDAI-2K).

RESULTS

CRP levels were increased in SLE patients compared to controls, but were not associated with SLEDAI-2K or IL-6 levels. However, exclusion of patients carrying at least one rs1205 minor allele revealed an association between disease activity and CRP levels (P = 0.005). We found a strong association between disease activity and CRP levels (P < 0.0005) when patients with measurable IFNα levels as well as the minor allele of rs1205 were excluded from the analysis. Similarly, when patients with elevated IFNα levels and/or the rs1205 polymorphism were excluded, IL-6 levels were associated with CRP levels.

CONCLUSION

The present study demonstrates that the serum IFNα level as well as the CRP genotype affect the CRP response in SLE patients. Lack of correlation between serum levels of CRP and disease activity could therefore be explained by activation of the type I IFN system and polymorphisms in the CRP gene.

Elevated C-reactive protein, depression, somatic diseases, and all-cause mortality: a mendelian randomization study

BACKGROUND

Elevated levels of plasma C-reactive protein (CRP) have been associated with many diseases including depression, but it remains unclear whether this association is causal. We tested the hypothesis that CRP is causally associated with depression, and compared these results to those for cancer, ischemic heart disease, chronic obstructive pulmonary disease, and all-cause mortality.

METHODS

We performed prospective and instrumental variable analyses using plasma CRP levels and four CRP genotypes on 78,809 randomly selected 20- to 100-year-old men and women from the Danish general population. End points included hospitalization or death with depression and somatic diseases, prescription antidepressant medication use, and all-cause mortality.

RESULTS

A doubling in plasma CRP yielded an observed odds ratio (OR) of 1.28 (95% confidence interval [CI]: 1.23-1.33) for hospitalization or death with depression, whereas for genetically elevated CRP, the causal OR was .79 (95% CI: .51-1.22; observed vs. causal estimate, p = .03). For prescription antidepressant medication use, corresponding ORs were 1.12 (1.11-1.15) and .98 (.83-1.15; p = .08). These results were similar to those for risk of cancer (p = .002), ischemic heart disease (p = 4 × 10(-99)), chronic obstructive pulmonary disease (p = 6 × 10(-86)), and all-cause mortality (p = .001) examined in the same individuals.

CONCLUSIONS

Elevated CRP was associated with increased risk of depression in individuals in the general population, but genetically elevated CRP was not. This indicates that CRP per se is not a causal risk factor for depression.

Genetic and environmental influences on the prospective correlation between systemic inflammation and coronary heart disease death in male twins

OBJECTIVE

Because of lack of evidence, we aimed to examine to what degree low-grade systemic inflammation and coronary heart disease (CHD) death shared common genetic and environmental substrates.

APPROACH AND RESULTS

From the 41-year prospective National Heart, Lung, and Blood Institute Twin Study, we included 950 middle-aged male twins at baseline (1969-1973). Low-grade systemic inflammation was measured with plasma levels of interleukin-6 (IL-6) and C-reactive protein. Univariate and bivariate structural equation models were used, adjusted for a risk score for CHD death. The score-adjusted heritability was 19% for IL-6, 27% for C-reactive protein, and 22% for CHD death. The positive phenotypic correlation of IL-6 with CHD death (radjusted=0.27; 95% confidence interval [CI], 0.08-0.43) was driven by additive genetic factors (contribution [relative contribution], 0.30 [111%]) but attenuated by unique environment (-0.03 [-11%]). The genetic correlation between IL-6 and CHD death was 0.74 (95% CI, 0.21-1.00), whereas the unique environmental correlation was -0.05 (95% CI, -0.35 to 0.25). The proportion of genetic variance for CHD death shared with that for IL-6 was 74%. The phenotypic correlation of C-reactive protein with CHD death (radjusted=0.10; 95% CI, -0.02 to 0.22) was explained by additive genetic factors (0.20 [149%]) but was attenuated by the unique environment (-0.09 [-49%]). The genetic correlation of C-reactive protein with CHD death was 0.63 (95% CI, -0.07 to 1.00), whereas the unique environmental correlation was -0.07 (95% CI, -0.29 to 0.17).

CONCLUSIONS

Low-grade systemic inflammation, measured by IL-6, and long-term CHD death share moderate genetic substrates that augment both traits.

Genetic variants in C-reactive protein and ischemic stroke susceptibility

Considerable discrepancies in the previously reported associations of the C-reactive protein (CRP) gene variants and ischemic stroke (IS) risk prompted us to perform this meta-analysis. We selected the fixed effects Mantel-Haenszel method to estimate the risk of IS [OR (odds ratio) along with its 95 % CI (confidence interval)] in relation to the CRP variants (-717 A > G, 1444 C > T). Heterogeneity test, influence analysis and publication bias test were appropriately performed using respective methods. We analyzed 1,926 IS patients and 2,678 controls and found the -717 A > G variant was not significantly associated with overall IS risk. Subsequent analysis of the 1444 C > T variant involving 3,278 samples similarly revealed no significant association with IS. There was no substantial heterogeneity or publication bias in this analysis. Our meta-analysis may provide first evidence showing that genetic variants within the CRP locus are unlikely to modulate risk of IS.

A novel haplotype within C-reactive protein gene influences CRP levels and coronary heart disease risk in Northwest Indians

According to several epidemiological and clinical studies, the concentration of C-reactive protein (CRP) in blood is associated with the risk of coronary heart disease (CHD). However, these studies are limited in high incidence and prevalence area of North-West India. The present case control study investigated the contribution of three relevant CRP single nucleotide polymorphisms: -717A>G located in the promoter region (rs2794521), +1059G>C on exon2 (rs1800947) and +1444C>T in the 3' UTR (rs1130864) in 180 angiographically verified CHD cases and 175 control subjects. Minor allele frequencies (G, C and T) of rs2794521, rs1800947 and rs1130864 are observed to be 21.1, 11.7, 29.4 and 11.4, 10.0, 19.7 % in CHD cases and controls respectively. AA genotype of -717A>G and TT genotype of +1444C>T were significantly associated (P = 0.02 & 0.03 respectively) with the risk of CHD whereas, +1059G and +1444T were found to be strongly related (P = 0.023 & P = 0.008 respectively) with multivariable adjusted CRP levels. AGT Haplotype was significantly associated with the adjusted CRP levels (P < 0.05). Disease association analysis revealed that haplotype AGT influences CHD risk (OR 2.4, 95 % CI 1.23-4.84, P = 0.006) which exacerbates after correcting the confounding effects of risk variables (OR 2.5, 95 % CI 1.27-4.99, P = 0.004). With the global index of Akaike information criterion, it has been observed that the carrying each single unit of this susceptibility haplotype increases CHD risk by a value of 2.41 ± 0.439 (β ± SE) in the recessive mode.

Serum C-reactive protein level but not its gene polymorphism is associated with Takayasu arteritis

Takayasu arteritis (TA) patients with active disease often have elevated serum C-reactive protein (CRP) levels, which usually decline with the disease remission. The serum CRP concentration has been showed to be related to CRP gene polymorphisms in previous studies. The present study aims to investigate the associations of serum level of CRP and CRP polymorphisms with TA. A total of 178 unrelated Chinese Han TA patients and 229 unrelated Chinese Han individuals without documented disease were enrolled in our studies. After a systemic search in the HapMap database, four single-nucleotide polymorphisms (SNPs) were selected, namely, rs1800947, rs3093077, rs1205, and rs2808630. The ligase detection reaction (LDR) was used in genotyping. CRP concentrations were determined using turbidimetric immunoassay. Genotype frequencies and allele frequencies of CRP variations were similar between TA patients and controls. CRP haplotype frequencies in patients were not significantly different from those of controls. No significant association between serum CRP concentrations and genotypes was found. Moreover, no association was found in CRP concentration between patients with types I, II, and III TA or between patients with or without pulmonary involvement. By contrast, serum CRP concentration was directly correlated with disease severity. In conclusion, CRP polymorphisms were not associated with TA susceptibility or serum CRP levels in the Chinese Han population. However, higher CRP level was correlated with a more serious disease status, which implies that CRP possibly contributes to the progression of TA.

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.

Evaluation of the potential for lymph node metastasis using CRP 1846C>T genetic polymorphism in invasive breast cancer

Lymph node status is a key indicator of the best approach to treatment of invasive breast cancer. However, the accuracy with which lymph node metastasis is diagnosed is not currently satisfactory. New and more reliable methods that enable one to know who has a greater potential for lymph node metastasis would be highly desirable. We previously reported that lymph node involvement in esophageal and lung cancer may have a genetic component: C-reactive protein (CRP) 1846C>T genetic polymorphism. Here we examined the diagnostic value of CRP 1846C>T polymorphism for assessing the risk of lymph node metastasis in cases of invasive breast cancer. The study participants were 185 women with invasive breast cancer who underwent curative surgery with lymph node dissection. Using DNA from blood samples and polymerase chain reaction-restriction fragment length polymorphism, the utility of CRP genetic 1846C>T polymorphism (rs1205) for assessing the risk of lymph node metastasis was evaluated. Fifty-two (28 %) patients had lymph node metastasis. After the patients were divided into two groups based on their CRP 1846 genotypes (C/C+C/T and T/T), the clinical characteristics did not differ between the groups, but there was a significantly greater incidence of lymph node metastasis among patients in the T/T group. Moreover, the odds ratio for lymph node involvement in patients carrying the 1846 T/T genotype was more than 2.2 in multivariate logistic regression models. CRP genetic polymorphism may be a novel predictor of the risk of lymph node metastasis in invasive breast cancer.

Association of gene polymorphisms with the risk of warfarin bleeding complications at therapeutic INR in patients with mechanical cardiac valves

WHAT IS KNOWN AND OBJECTIVE

Pharmacogenetic studies of the genetic regulation of warfarin dose requirement have been reported, but few have been on the bleeding complications at therapeutic international normalized ratio (INR). This study aimed to evaluate the effect of gene polymorphisms of CYP2C9, VKORC1, thrombomodulin (THBD) and C-reactive protein (CRP) on the risk of bleeding complications of warfarin at therapeutic INR in Korean patients with mechanical cardiac valves.

METHODS

A retrospective warfarin pharmacogenetic association study was performed. One hundred and forty-two patients with mechanical cardiac valves who were on warfarin anticoagulation therapy and maintained INR levels of 2·0-3·0 for 3 consecutive time intervals were followed up. CYP2C9 rs1057910, VKORC1 rs9934438, CRP rs1205, THBD rs1042580 and THBD rs3176123 were genotyped. The association between genotypes and warfarin bleeding complications was evaluated using logistic regression analysis, adjusted for demographic and clinical factors.

RESULTS AND DISCUSSION

Of 142 eligible patients, 21 patients (14·8%) had bleeding complications at therapeutic INR. Patients with the G allele in THBD rs1042580 (AG or GG) had a lower risk of bleeding than patients with the AA genotype (adjusted OR: 0·210, 95% CI: 0·050-0·875, P = 0·032). The THBD rs3176123 polymorphism did not show any association with bleeding. For CRP rs1205, patients with the A allele (GA or AA genotype) had a higher risk of bleeding than patients with the GG genotype (adjusted OR: 5·575, 95% CI: 1·409-22·058, P = 0·014). Variant VKORC1 and CYP2C9 genotypes did not confer a significant increase in the risk for bleeding complications.

WHAT IS NEW AND CONCLUSIONS

As expected, no association could be found between bleeding complications and two dose-related genes (CYP2C9*3 and VKORC1 rs9934438). In contrast, our results suggest that two genetic markers (THBD rs1042580 and CRP rs1205) could be predictors of bleeding complications of warfarin at normal INR. Given the retrospective study design and the relatively small sample size, our hypothesis requires further independent validation using more robust prospective designs. However, additional retrospective studies similar to ours but in populations with different genetic backgrounds should also be useful.