Polymorphism at the C-reactive protein locus influences gene expression and predisposes to systemic lupus erythematosus

Phytochemical production and antioxidant activity improvement of Rhinacanthus nasutus (L.) Kurz calli by in vitro polyploidization

Background

Rhinacanthus nasutus (L.) Kurz is a multipurpose ethnomedicinal shrub containing various bioactive compounds and phytochemicals. Inducing polyploidy is an alternative way to enhance the production of secondary metabolites in medicinal plants. The main objectives of this research were to study the effect of polyploidization on the phytochemical content and antioxidant activity of R. nasutus calli.

Methods

In vitro polyploidy was induced by soaking calli in colchicine at different concentrations and for different exposure times. To determine callus polyploidy, the relative DNA contents of each sample were examined using flow cytometry. Diploid, tetraploid, and mixoploid calli were extracted to determine the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity.

Results and conclusion

Results showed that the callus survival rate decreased with increasing colchicine concentration and exposure time. The highest percentage of induced tetraploid (66.67%) and mixoploid (66.67%) calli were obtained at 0.05% and 0.2% colchicine with exposure times of 48 and 24 h, respectively. Tetraploid calli showed the highest TPC (81.28 mg GAE/g extract), TFC (35.33 mg QE/g extract), and antioxidant activity compared to diploid and mixoploid calli. Additionally, tetraploid calli demonstrated an approximately twofold greater increase in TPC and TFC compared to diploid calli. The analysis of polyploid callus samples revealed that tetraploid calli exhibited the highest antioxidant activity, whereas diploid calli demonstrated the lowest antioxidant activity across all applied assays. Therefore, inducing a tetraploid of R. nasutus calli plays a critical role in modifying phytochemical content and antioxidant activity.

Recurrent pericarditis with normal C-reactive protein: Clinical and laboratory features, biomarkers and outcome in a non-inflammatory phenotype

BACKGROUND

Differences in recurrent pericarditis with normal vs. elevated C-reactive protein (CRP) are unknown.

MATERIALS AND METHODS

We studied 448 patients with recurrent or incessant pericarditis. CRP levels <10 mg/L were considered normal. Forty-one patients with normal CRP were tested for interleukin 6 (IL-6), serum amyloid A (SAA) and soluble urokinase plasminogen activator receptor (suPAR).

RESULTS

Among the cohort (median age 43 years, 48.4% females), 336 patients (75%) had elevated CRP, while 112 (25%) had normal levels. CRP-negative patients were younger (38.6 vs. 43.5 years, p=0.007) and predominantly female (67.9% vs. 42.0%, p<0.001). They presented less often with fever (23.2% vs. 74.1%, p<0.001), pleural involvement (7.1% vs. 61.6% p<0.001), and neutrophilic leucocytosis (WBC 6760 vs. 12315/µL, p<0.001). Pericardiocentesis was performed rarely in CRP-negative patients (2.7% vs. 13.4%, p=0.001). Recurrence rates were similar (5.4 vs. 5.5/100 months-patient, p=0.918). Among CRP-negative patients, 53 (47.3%) had an incessant course characterized by persistent symptoms (pain and tachycardia); abnormal instrumental findings included ECG changes (28.6%), mild pericardial effusion (86.6%), and cardiac magnetic resonance evidence of effusion/oedema/late gadolinium enhancement (43.7%). Anakinra was administered to 48 CRP-positive (14.3%) and 10 CRP-negative patients (8.9%), leading to good responses with discontinuation of NSAIDs and corticosteroids in 39/48 (81.2%) and 5/10 (50.0%), respectively. Among the 41 CRP-negative patients tested, IL-6 and suPAR levels were always normal, while SAA was elevated in 17.1%.

CONCLUSIONS

Pericarditis with normal CRP exhibits distinct clinical and laboratory features, often presenting with an incessant course. Although rarely elevated, SAA may help to identify inflammation beyond CRP.

Single‑nucleotide polymorphisms in the promoter of the gene encoding for C‑reactive protein associated with acute coronary syndrome

Acute coronary syndrome (ACS) is a leading cause of mortality worldwide. Several studies have shown that certain single nucleotide polymorphisms (SNPs) are linked to the development of ACS. In particular, C-reactive protein (CRP) has emerged as an important predictive biomarker for cardiovascular disease. The current study aimed to investigate four polymorphisms of the CRP gene as possible biomarkers for ACS in a sample of 252 individuals (114 patients with ACS and 138 healthy controls) from Southeastern Mexico. Multivariate analysis adjusted for clinical variables showed that the polymorphism 3872CT for the genotype CC/CT [adjusted Odds Ratio (AdOR)=3.78; 95% Confidence Interval (CI): 1.11-12.92; P=0.034] and the genotype GG/GC of the polymorphisms 2667CG (AdOR=4.82; 95% CI: 1.69-13.72; P=0.02) were associated with ACS. However, the polymorphisms 3006AC genotype AA/AC and 5237GA genotype GG/GC were not found to be associated in the multivariate analysis with ACS (P>0.05). These results suggested that 3872CC/CT and 2667CC/CG polymorphism of the CRP gene plays a significant role in the development of ACS.

Genetic susceptibility and clinical features of CYP2D6 associated with systemic lupus erythematosus in a Chinese population

OBJECTIVE

This study aims to explore possible susceptibility genes and clinical features for systemic lupus erythematosus (SLE) patients in a Chinese population.

METHODS

Expanding on the results of a prior single-center observational study involving 60 systemic lupus erythematosus patients, a subsequent single-center prospective observational study was conducted on SLE patients undergoing treatment at Nanfang Hospital Affiliated to Southern Medical University from 2021 to 2023. The identification process for drug-related target genes entailed an extensive search across PharmGKB (https://www.pharmgkb.org/), the Clinical Pharmacogenetics Implementation Consortium (CPIC),and PubMed literature databases, to pinpoint common drugs and target single nucleotide polymorphisms(SNPs)for SLE. Blood samples were individually collected and genotyped using MassARRAY® high-throughput nucleic acid mass spectrometry. Genotype frequency differences were assessed through Chi-square tests against both the larger East Asian population as well as kidney transplant recipients. Data collection relied on electronic medical records, encompassing demographic details(age, gender),medication regimens(hormones, NSAIDs, hydroxychloroquine, DMARDs, biologic agents, stomach medications, calcitriol, etc.),laboratory indicators(RF, Anti-CCP antibody, ESR, CRP, anti-ANA antibodies, dsDNA antibodies, anti-SM antibodies, S m. RNP antibodies, A LT, ALB, CR, UA, WBC, PLT, HGB, Ca, K, Glu, CHOL, TG, LDL-C, HDL-C) and lupus activity scores(SLEDAI-2K). Possible disease susceptibility genes were categorized, and SPSS26 software facilitated statistical analyses.

RESULTS

The research encompassed a total of 137 SLE patients along with 50 SNPs. After conducting statistical analyses, it emerged that there existed significant disparities in CYP2D6 gene (rs1065852) distribution when compared against allele mutation rates within both East Asian populations (p < .05) and kidney transplant patients(p < .05). Wild-type gene (GG) constituted 14% of cases while mutant gene (GA + AA) constituted 86%. Allele mutation rate (A63.6%) was significantly higher among SLE patients (RR = 0.802; p = .0355). Furthermore, the variant rs1065852 genotype (GA + AA) demonstrated significant associations with lower CRP levels, higher HGB levels, and higher HDL-C levels (p < 0 0.05).

CONCLUSION

The metabolic enzyme CYP2D6 may be used as susceptibility gene for predicting systemic lupus erythematosus and are correlated with CRP and other indicators.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

C-reactive protein: a target for therapy to reduce inflammation

C-reactive protein (CRP) is well-recognized as a sensitive biomarker of inflammation. Association of elevations in plasma/serum CRP level with disease state has received considerable attention, even though CRP is not a specific indicator of a single disease state. Circulating CRP levels have been monitored with a varying degree of success to gauge disease severity or to predict disease progression and outcome. Elevations in CRP level have been implicated as a useful marker to identify patients at risk for cardiovascular disease and certain cancers, and to guide therapy in a context-dependent manner. Since even strong associations do not establish causality, the pathogenic role of CRP has often been over-interpreted. CRP functions as an important modulator of host defense against bacterial infection, tissue injury and autoimmunity. CRP exists in conformationally distinct forms, which exhibit distinct functional properties and help explaining the diverse, often contradictory effects attributed to CRP. In particular, dissociation of native pentameric CRP into its subunits, monomeric CRP, unmasks "hidden" pro-inflammatory activities in pentameric CRP. Here, we review recent advances in CRP targeting strategies, therapeutic lowering of circulating CRP level and development of CRP antagonists, and a conformation change inhibitor in particular. We will also discuss their therapeutic potential in mitigating the deleterious actions attributed to CRP under various pathologies, including cardiovascular, pulmonary and autoimmune diseases and cancer.

Association of C-reactive protein and complement factor H gene polymorphisms with risk of lupus nephritis in Chinese population

BACKGROUND

Complement overactivation is a major driver of lupus nephritis (LN). Impaired interactions of C-reactive protein (CRP) with complement factor H (CFH) have been shown as a pathogenic mechanism that contributes to the overactivation of complement in LN. However, genetic variations of neither CRP nor CFH show consistent influences on the risk of LN.

AIM

To examine whether genetic variations of CRP and CFH in combination can improve the risk stratification in Chinese population.

METHODS

We genotyped six CRP single nucleotide polymorphisms (SNPs) (rs1205, rs3093062, rs2794521, rs1800947, rs3093077, and rs1130864) and three CFH SNPs (rs482934, rs1061170, and rs1061147) in 270 LN patients and 303 healthy subjects.

RESULTS

No linkage was found among CRP and CFH SNPs, indicating lack of genetic interactions between the two genes. Moreover, CRP and CFH SNPs, neither individually nor in combination, are associated with the risk or clinical manifestations of LN. Given the unambiguous pathogenic roles of the two genes.

CONCLUSION

These findings suggest that the biological effects of most genetic variations of CRP and CFH on their expressions or activities are not sufficient to influence the disease course of LN.

The Complex Role of C-Reactive Protein in Systemic Lupus Erythematosus

C-reactive protein (CRP) is well-known as a sensitive albeit unspecific biomarker of inflammation. In most rheumatic conditions, the level of this evolutionarily highly conserved pattern recognition molecule conveys reliable information regarding the degree of ongoing inflammation, driven mainly by interleukin-6. However, the underlying causes of increased CRP levels are numerous, including both infections and malignancies. In addition, low to moderate increases in CRP predict subsequent cardiovascular events, often occurring years later, in patients with angina and in healthy individuals. However, autoimmune diseases characterized by the Type I interferon gene signature (e.g., systemic lupus erythematosus, primary Sjögren’s syndrome and inflammatory myopathies) represent exceptions to the general rule that the concentrations of CRP correlate with the extent and severity of inflammation. In fact, adequate levels of CRP can be beneficial in autoimmune conditions, in that they contribute to efficient clearance of cell remnants and immune complexes through complement activation/modulation, opsonization and phagocytosis. Furthermore, emerging data indicate that CRP constitutes an autoantigen in systemic lupus erythematosus. At the same time, the increased risks of cardiovascular and cerebrovascular diseases in patients diagnosed with systemic lupus erythematosus and rheumatoid arthritis are well-established, with significant impacts on quality of life, accrual of organ damage, and premature mortality. This review describes CRP-mediated biological effects and the regulation of CRP release in relation to aspects of cardiovascular disease and mechanisms of autoimmunity, with particular focus on systemic lupus erythematosus.

C-Reactive Protein Levels in Systemic Lupus Erythematosus Are Modulated by the Interferon Gene Signature and CRP Gene Polymorphism rs1205

Objectives

Patients with systemic lupus erythematosus (SLE) often display modest elevations of C-reactive protein (CRP) despite raised disease activity and increased interleukin (IL-) 6. We asked to what extent IL-6 levels, the CRP polymorphism rs1205, and the type I interferon (IFN) gene signature affects the basal CRP levels in patients with SLE during a quiescent phase of the disease.

Methods

CRP and IL-6 were analyzed in plasma from 57 patients meeting established classification criteria for SLE. The CRP polymorphism rs1205 was assessed and gene expression analyzed including four type I IFN-regulated genes (IGS).

Results

CRP was increased in patients with detectable IL-6 levels (p=0.001) and decreased among IGS-positive subjects (p=0.033). A multiple linear regression model revealed IL-6 to have a positive association with CRP levels, whereas both IGS-positivity and CRP genotype (rs1205) AA/GA were negatively associated with CRP-levels.

Conclusion

Our data offer an explanation to the modest CRP levels seen in viral infections and IFN-α driven autoimmunity and corroborate prior observations showing an IFN-α dependent downregulation of CRP. The latter observation, together with the fact that the CRP-lowering polymorphism rs1205 is overrepresented in human SLE, could explain low basal CRP and inadequate CRP-responses among patients with active SLE.

Update on C-reactive protein and fecal calprotectin: are they accurate measures of disease activity in Crohn's disease?

'Treat-to-target' paradigms in Crohn's disease (CD) directed at suppressing intestinal inflammation require accurate and reliable measures of disease activity. Although endoscopy has traditionally been considered a gold standard, cost, complexity, resource limitations, and invasiveness are important limitations. Hence, substantial interest exists for non-invasive serum and fecal biomarkers, namely C-reactive protein (CRP) and fecal calprotectin (FC), in the diagnosis, monitoring, and treatment of CD. Areas covered: We review the evidence for using serum CRP and FC in distinguishing patients with CD from those with irritable bowel syndrome, categorizing disease activity among patients with an established diagnosis of CD, predicting the likelihood of treatment response, identifying asymptomatic patients in medically or surgically induced remission who are at risk for disease relapse, and as treatment targets. Expert commentary: Accurate interpretation of CRP and FC is dependent on several factors including the clinical context, the performance characteristics of the assay, the specified test cut-offs, and the pre-test probability of disease. Emerging evidence indicates that CRP and FC are valuable adjuncts for the management of CD in specific circumstances described in this review.

Iodine Quantification on Spectral Detector-Based Dual-Energy CT Enterography: Correlation with Crohn's Disease Activity Index and External Validation

Objective

To correlate CT parameters on detector-based dual-energy CT enterography (DECTE) with Crohn's disease activity index (CDAI) and externally validate quantitative CT parameters.

Materials and Methods

Thirty-nine patients with CD were retrospectively enrolled. Two radiologists reviewed DECTE images by consensus for qualitative and quantitative CT features. CT attenuation and iodine concentration for the diseased bowel were also measured. Univariate statistical tests were used to evaluate whether there was a significant difference in CTE features between remission and active groups, on the basis of the CDAI score. Pearson's correlation test and multiple linear regression analyses were used to assess the correlation between quantitative CT parameters and CDAI. For external validation, an additional 33 consecutive patients were recruited. The correlation and concordance rate were calculated between real and estimated CDAI.

Results

There were significant differences between remission and active groups in the bowel enhancement pattern, subjective degree of enhancement, mesenteric fat infiltration, comb sign, and obstruction (p < 0.05). Significant correlations were found between CDAI and quantitative CT parameters, including number of lesions (correlation coefficient, r = 0.573), bowel wall thickness (r = 0.477), iodine concentration (r = 0.744), and relative degree of enhancement (r = 0.541; p < 0.05). Iodine concentration remained the sole independent variable associated with CDAI in multivariate analysis (p = 0.001). The linear regression equation for CDAI (y) and iodine concentration (x) was y = 53.549x + 55.111. For validation patients, a significant correlation (r = 0.925; p < 0.001) and high concordance rate (87.9%, 29/33) were observed between real and estimated CDAIs.

Conclusion

Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD.

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.

Article Commentary: Serum C-Reactive Protein (CRP), Target for Therapy or Trouble?

High sensitivity serum C-reactive protein (hs-CRP) has come into clinical use as a marker of risk for cardiovascular disease (CVD). In addition to a role as a marker of disease, CRP has also been implicated in the pathogenesis of CVD. Specific small-molecule inhibitors of CRP have recently been developed with the intent of mitigating cardiac damage during acute myocardial infarction. However, the use of CRP, both as a risk marker and a disease target are controversial for several reasons. Serum hs-CRP concentrations can be elevated on the basis of genetics, female gender, and non-Caucasian ethnicity. It is not clear, in these contexts, that elevations of hs-CRP have any pathological significance. As a non-specific indicator of inflammation, CRP is also not a specific indicator of a single disease state such as cardiovascular disease but elevated concentrations can be seen in association with other comorbidities including obesity and pulmonary disease. In sharp contrast to the proposed inhibition of CRP for cardiovascular disease treatment, the infusion of CRP has been shown to have profound therapeutic benefits for autoimmune disease and septic shock. The balance between the risks and benefits of these competing views of the role of CRP in disease and disease therapy is reminiscent of the ongoing controversy regarding the use of non-steroidal anti-inflammatory drugs (NSAIDs) for musculoskeletal disease and their cardiovascular side effects. Soon, NSAIDs may not be the only agents about which Rheumatologists and Cardiologists may spar.

Modelling clinical systemic lupus erythematosus: similarities, differences and success stories

Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Magnetic resonance enterography has good inter-rater agreement and diagnostic accuracy for detecting inflammation in pediatric Crohn disease

BACKGROUND

Magnetic resonance enterography (MRE) is increasingly relied upon for noninvasive assessment of intestinal inflammation in Crohn disease. However very few studies have examined the diagnostic accuracy of individual MRE signs in children.

OBJECTIVE

We have created an MR-based multi-item measure of intestinal inflammation in children with Crohn disease - the Pediatric Inflammatory Crohn's MRE Index (PICMI). To inform item selection for this instrument, we explored the inter-rater agreement and diagnostic accuracy of individual MRE signs of inflammation in pediatric Crohn disease and compared our findings with the reference standards of the weighted Pediatric Crohn's Disease Activity Index (wPCDAI) and C-reactive protein (CRP).

MATERIALS AND METHODS

In this cross-sectional single-center study, MRE studies in 48 children with diagnosed Crohn disease (66% male, median age 15.5 years) were reviewed by two independent radiologists for the presence of 15 MRE signs of inflammation. Using kappa statistics we explored inter-rater agreement for each MRE sign across 10 anatomical segments of the gastrointestinal tract. We correlated MRE signs with the reference standards using correlation coefficients. Radiologists measured the length of inflamed bowel in each segment of the gastrointestinal tract. In each segment, MRE signs were scored as either binary (0-absent, 1-present), or ordinal (0-absent, 1-mild, 2-marked). These segmental scores were weighted by the length of involved bowel and were summed to produce a weighted score per patient for each MRE sign. Using a combination of wPCDAI≥12.5 and CRP≥5 to define active inflammation, we calculated area under the receiver operating characteristic curve (AUC) for each weighted MRE sign.

RESULTS

Bowel wall enhancement, wall T2 hyperintensity, wall thickening and wall diffusion-weighted imaging (DWI) hyperintensity were most commonly identified. Inter-rater agreement was best for decreased motility and wall DWI hyperintensity (kappa≥0.64). Correlation between MRE signs and wPCDAI was higher than with CRP. AUC was highest (≥0.75) for ulcers, wall enhancement, wall thickening, wall T2 hyperintensity and wall DWI hyperintensity.

CONCLUSION

Some MRE signs had good inter-rater agreement and AUC for detection of inflammation in children with Crohn disease.

Interferon-α coincides with suppressed levels of pentraxin-3 (PTX3) in systemic lupus erythematosus and regulates leucocyte PTX3 in vitro

Dysfunctional elimination of cell debris, and the role of opsonins such as pentraxins, is of interest regarding systemic lupus erythematosus (SLE) pathogenesis. Interferon (IFN)-α is typically elevated during SLE flares, and inhibits hepatocyte production of the pentraxin 'C-reactive protein' (CRP), partly explaining the poor correlation between CRP levels and SLE disease activity. The extrahepatically produced 'pentraxin 3' (PTX3) shares waste disposal functions with CRP, but has not been studied extensively in SLE. We analysed serum PTX3 in SLE, and assessed its interference with IFN-α in vitro. Serum samples from 243 patients with SLE and 100 blood donors were analysed regarding PTX3. Patient sera were analysed for IFN-α, and genotyped for three PTX3 single nucleotide polymorphisms reported previously to associate with PTX3 levels. Stimulated PTX3 release was assessed in the presence or absence of IFN-α in blood donor neutrophils and peripheral blood mononuclear cells (PBMC). Serum PTX3 was 44% lower in patients with SLE compared to blood donors (P < 0·0001) and correlated with leucocyte variables. Patients with undetectable IFN-α had 29% higher median PTX3 level than patients with detectable IFN-α (P = 0·01). PTX3 production by PBMC was inhibited by IFN-α, whereas neutrophil degranulation of PTX3 was increased. No differences in PTX3 levels were observed between the SNPs. In conclusion, median serum PTX3 is lower in SLE (especially when IFN-α is detectable) compared to blood donors. In addition to its potential consumption during waste disposal, it is plausible that IFN-α also attenuates PTX3 by inhibiting synthesis by PBMC and/or exhausting PTX3 storage in neutrophil granules.

Kruppel-like factor4 regulates PRDM1 expression through binding to an autoimmune risk allele

A SNP identified as rs548234, which is found in PRDM1, the gene that encodes BLIMP1, is a risk allele associated with systemic lupus erythematosus (SLE). BLIMP1 expression was reported to be decreased in women with the PRDM1 rs548234 risk allele compared with women with the nonrisk allele in monocyte-derived DCs (MO-DCs). In this study, we demonstrate that BLIMP1 expression is regulated by the binding of Kruppel-like factor 4 (KLF4) to the risk SNP. KLF4 is highly expressed in MO-DCs but undetectable in B cells, consistent with the lack of altered expression of BLIMP1 in B cells from risk SNP carriers. Female rs548234 risk allele carriers, but not nonrisk allele carriers, exhibited decreased levels of BLIMP1 in MO-DCs, showing that the regulatory function of KLF4 is influenced by the risk allele. In addition, KLF4 directly recruits histone deacetylases (HDAC4, HDAC6, and HDAC7), established negative regulators of gene expression. Finally, the knock down of KLF4 expression reversed the inhibitory effects of the risk SNP on promoter activity and BLIMP1 expression. Therefore, the binding of KLF4 and the subsequent recruitment of HDACs represent a mechanism for reduced BLIMP1 expression in MO-DCs bearing the SLE risk allele rs548234.

Endocan Levels and Subclinical Atherosclerosis in Patients With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology. A major cause of morbidity and mortality in SLE is accelerated atherosclerosis. Endothelial-specific molecule 1 (endocan) is a potential predictor of vascular events and is expressed in response to inflammatory cytokines in endothelial cells. We investigated the relationship between endocan and carotid intima-media thickness (cIMT) as a marker of early atherosclerosis. We included 44 women with SLE and 44 healthy women as controls. Disease severity of SLE was evaluated using the SLE Disease Activity Index. Endocan, C-reactive protein, erythrocyte sedimentation rate (ESR), and lipid panel were measured. The cIMT was 0.70 (range: 0.45-1.20) mm in patients with SLE and 0.40 (0.25-0.60) mm in controls (P < .001). Endocan value was 1.6 ± 0.9 ng/mL in controls and 2.2 ± 1.0 ng/mL in patients with SLE (P = .014). Endocan levels were positively correlated with cIMT (r = .469, P < .001), body mass index (r = .373, P = .013), and ESR (r = .393, P = .008). Endocan level may be associated with subclinical atherosclerosis in SLE. Consequently, endocan levels may be a promising clinical tool for patients with SLE as a guide for preventive strategy.

Cell death in the pathogenesis of systemic lupus erythematosus and lupus nephritis

Nephritis is one of the most severe complications of systemic lupus erythematosus (SLE). One key characteristic of lupus nephritis (LN) is the deposition of immune complexes containing nucleic acids and/or proteins binding to nucleic acids and autoantibodies recognizing these molecules. A variety of cell death processes are implicated in the generation and externalization of modified nuclear autoantigens and in the development of LN. Among these processes, apoptosis, primary and secondary necrosis, NETosis, necroptosis, pyroptosis, and autophagy have been proposed to play roles in tissue damage and immune dysregulation. Cell death occurs in healthy individuals during conditions of homeostasis yet autoimmunity does not develop, at least in part, because of rapid clearance of dying cells. In SLE, accelerated cell death combined with a clearance deficiency may lead to the accumulation and externalization of nuclear autoantigens and to autoantibody production. In addition, specific types of cell death may modify autoantigens and alter their immunogenicity. These modified molecules may then become novel targets of the immune system and promote autoimmune responses in predisposed hosts. In this review, we examine various cell death pathways and discuss how enhanced cell death, impaired clearance, and post-translational modifications of proteins could contribute to the development of lupus nephritis.

Association of inflammatory gene polymorphisms with mechanical heart valve reoperation

Background

Various complications lead to reoperation in patients who undergo prosthetic valve replacement where inflammatory process could be involved. The goals of this study were to identify risk factors that correlate with reoperation in patients with prosthetic heart valves and to investigate the relationship between reoperation and inflammatory gene polymorphisms.

Results

The study included 228 patients from the EwhA–Severance Treatment Group of Warfarin. Single nucleotide polymorphisms of c-reactive protein (CRP), interferon-gamma, interleukin 1 beta, interleukin 6, interleukin 10, transforming growth factor beta 1, and tumor necrosis factor genes were genotyped by means of SNaPshot and TaqMan assays. Thirty-nine patients (17.1 %) underwent more than one heart valve operation. A threefold increased risk for heart valve reoperation was evident in homozygous variant-type (TT) carriers as compared with ancestral allele carriers of CRP rs1205. Logistic regression analysis revealed that CRP rs1205 (OR 2.68, 95 % CI 1.22–5.90, p = 0.014), valve position (mitral valve OR 2.80, 95 % CI 1.01–7.80, p = 0.048; tricuspid valve OR 9.24, 95 % CI 2.46–34.70, p = 0.001; reference: aortic valve) and time after first operation (OR 1.13, 95 % CI 1.06–1.20, p < 0.001) affected the risk of reoperation.

Conclusions

Inflammatory gene polymorphisms could be a possible marker of risk for reoperation in patients with prosthetic heart valve surgery.

Selecting instruments for Mendelian randomization in the wake of genome-wide association studies

Mendelian randomization (MR) studies typically assess the pathogenic relevance of environmental exposures or disease biomarkers, using genetic variants that instrument these exposures. The approach is gaining popularity-our systematic review reveals a greater than 10-fold increase in MR studies published between 2004 and 2015. When the MR paradigm was first proposed, few biomarker- or exposure-related genetic variants were known, most having been identified by candidate gene studies. However, genome-wide association studies (GWAS) are now providing a rich source of potential instruments for MR analysis. Many early reviews covering the concept, applications and analytical aspects of the MR technique preceded the surge in GWAS, and thus the question of how best to select instruments for MR studies from the now extensive pool of available variants has received insufficient attention. Here we focus on the most common category of MR studies-those concerning disease biomarkers. We consider how the selection of instruments for MR analysis from GWAS requires consideration of: the assumptions underlying the MR approach; the biology of the biomarker; the genome-wide distribution, frequency and effect size of biomarker-associated variants (the genetic architecture); and the specificity of the genetic associations. Based on this, we develop guidance that may help investigators to plan and readers interpret MR studies.

CRP 1846C>T Genetic Polymorphism Is Associated with Lymph Node Metastasis and/or Severe Lymphatic Invasion in Endometrial Cancer

Endometrial cancer (EC) rates are rising in Japan. Lymph node (LN) metastasis is an important prognostic factor in EC, and its risk is increased with higher tumor grade, deep myometrial invasion, larger tumor size, and lymphovascular space invasion (LVSI). Current methodologies to assess these factors are unreliable. We previously showed the association between C-reactive protein (CRP) 1846C>T (rs1205) polymorphism and LN metastasis in esophageal, non-small cell lung, and breast cancers. The CRP gene is located on chromosome 1q21-q23, and the polymorphism in the noncoding region (1846C>T) of this gene decreases serum CRP levels. We investigated the relationship between CRP 1846C>T genetic polymorphism and LN metastasis or LVSI in 130 EC patients using polymerase chain reaction-restriction fragment length polymorphism. The CRP 1846C/T genotype was C/C in 11 patients, C/T in 58 patients and T/T in 61 patients. The patients were divided into two groups based on their CRP 1846 genotypes: "C/C" and "C/T + T/T". Nine (7%) and 18 (13%) patients, all with the polymorphism, had LN metastasis and moderate or prominent lymphatic invasion, respectively. LN metastasis and/or severe lymphatic invasion were observed in the C/T + T/T group, while patients with the C/C genotype had no LN metastases or severe lymphatic invasion. Univariate and multivariate logistic regression models revealed that the C/T + T/T patients had a significant likelihood of developing LN metastasis and/or severe lymphatic invasion. Our results suggest that CRP genetic polymorphism is a novel risk predictor of LN metastasis and/or lymphatic invasion in EC.

The Clinical Value of Soluble Urokinase Plasminogen Activator Receptor (suPAR) Levels in Autoimmune Connective Tissue Disorders

The assessment of the general inflammatory condition of patients with autoimmune connective tissue disorders (ACTD) is a major challenge. The use of traditional inflammatory markers including CRP-levels and erythrocyte sedimentation rate (ESR) is limited by several preanalytical factors and their low specificities. Soluble urokinase plasminogen activator receptor (suPAR) is one of the novel candidate markers that is increasingly used in immune mediated disorders. In our studies we compared suPAR levels of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and ankylosing spondylitis with those of healthy controls. suPAR provided valuable clinical information on disease activity in RA, SLE and SSc. We identified a subgroup of remitted RA patients, who presented still clinical symptoms of inflammatory activity which correlated to high plasma suPAR (while ESR and CRP were normal). In SLE we established specific suPAR cut-off values that support the discrimination between patients with high and those with moderate SLE activity. In patients with SSc suPAR correlated with objective measures of lung and other complications. In the majority of ACTDs including SLE, SSc or RA, suPAR is seemingly a good biomarker that would provide valuable clinical information. However, before the introduction of this novel parameter in laboratory repertoire important issues should be elucidated. These include the establishment of appropriate and disease specific cutoff values, clarification of interfering preanalytical values and underlying conditions and declaration of age- and gender-specific reference ranges.

Clearance Deficiency and Cell Death Pathways: A Model for the Pathogenesis of SLE

Alterations of cell death pathways, including apoptosis and the neutrophil specific kind of death called NETosis, can represent a potential source of autoantigens. Defects in the clearance of apoptotic cells may be responsible for the initiation of systemic autoimmunity in several chronic inflammatory diseases, including systemic lupus erythematosus (SLE). Autoantigens are released mainly from secondary necrotic cells because of a defective clearance of apoptotic cells or an inefficient degradation of DNA-containing neutrophil extracellular traps (NETs). These modified autoantigens are presented by follicular dendritic cells to autoreactive B cells in germinal centers of secondary lymphoid organs. This results in the loss of self-tolerance and production of autoantibodies, a unifying feature of SLE. Immune complexes (IC) are formed from autoantibodies bound to uncleared cellular debris in blood or tissues. Clearance of IC by blood phagocytes, macrophages, and dendritic cells leads to proinflammatory cytokine secretion. In particular, plasmacytoid dendritic cells produce high amounts of interferon-α upon IC uptake, thereby contributing to the interferon signature of patients with SLE. The clearance of antinuclear IC via Fc-gamma receptors is considered a central event in amplifying inflammatory immune responses in SLE. Along with this, the accumulation of cell remnants represents an initiating event of the etiology, while the subsequent generation of autoantibodies against nuclear antigens (including NETs) results in the perpetuation of inflammation and tissue damage in patients with SLE. Here, we discuss the implications of defective clearance of apoptotic cells and NETs in the development of clinical manifestations in SLE.

The relationship between C-reactive protein rs3091244 polymorphism and ankylosing spondylitis

AIMS

Previous studies have shown that C-reactive protein (CRP) gene polymorphism can be related to inflammatory changes. The present study aimed to examine the association between CRP gene polymorphism and clinical and laboratory findings in ankylosing spondylitis (AS) patients.

MATERIALS AND METHODS

A total of 80 patients, 40 with AS and 40 controls, were included in the study. Diagnosis of AS was made according to Assessment in AS International Working Group criteria. Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index and Bath Ankylosing Spondylitis Radiology Index scores were evaluated. CRP gene C, A and T alleles were evaluated and were determined using the analysis of melting curves after real time polymerase chain reaction. The odds ratios were calculated for all alleles and haploids of the CRP gene. We investigated the relationship between the CRP polymorphism and clinical and laboratory findings.

RESULTS

A, C, T allele frequencies in the control group were 15%, 57.5% and 27.5%. The allele frequencies in the AS group were 38%, 68.8% and 26.2%. While C and T allele frequencies were shown to be similar in the two groups, A allele frequency was higher in the AS group compared to the control group. The CC wild allele was 42.5% in the control group and 47.5% in the AS group (P = 1.0). Odds ratios for the C allele were 1.6, for the CC haploid 1.2 and for the CT haploid 3.7. Chest expansion and finger-to-ground distance was better in the CRP gene polymorphism group compared to the no polymorphism group.

CONCLUSION

The presence of the CRP gene CC wild haploid and C allele in patients may indicate an increased risk for AS.

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.

Adverse events of anti-tumor necrosis factor α therapy in ankylosing spondylitis

Objective

This study aims to investigate the prevalence of short-term and long-term adverse events associated with tumor necrosis factor-α (TNF-α) blocker treatment in Chinese Han patients suffering from ankylosing spondylitis (AS).

Methods

The study included 402 Chinese Han AS patients treated with TNF-α blockers. Baseline data was collected. All patients were monitored for adverse events 2 hours following administration. Long-term treatment was evaluated at 8, 12, 52 and 104 weeks follow-up for 172 patients treated with TNF-α blockers.

Results

Short-term adverse events occurred in 20.15% (81/402), including rash (3.5%; 14/402), pruritus (1.2%; 5/402), nausea (2.2%; 9/402), headache (0.7%; 3/402), skin allergies (4.0%; 16/402), fever (0.5%; 2/402), palpitations (3.0%; 12/402), dyspnea (0.5%; 2/402), chest pain (0.2%; 2/402), abdominal pain (1.0%; 4/402), hypertension (2.2%; 9/402), papilledema (0.5%; 2/402), laryngeal edema (0.2%; 1/402) and premature ventricular contraction (0.2%; 1/402). Long-term adverse events occurred in 59 (34.3%; 59/172) patients, including pneumonia (7.6%; 13/172), urinary tract infections (9.9%; 17/172), otitis media (4.7%; 8/172), tuberculosis (3.5%; 17/172), abscess (1.2%; 2/172), oral candidiasis (0.6%; 1/172), elevation of transaminase (1.7%; 3/172), anemia (1.2%; 2/172), hematuresis (0.6%; 1/172), constipation (2.3%; 4/172), weight loss (0.6%; 1/172), exfoliative dermatitis (0.6%; 1/172). CRP, ESR and disease duration were found to be associated with an increased risk of immediate and long-term adverse events (P<0.05). Long-term treatment with Infliximab was associated with more adverse events than rhTNFR-Fc (P<0.01).

Conclusion

This study reports on the prevalence of adverse events in short-term and long-term treatment with TNF-α blocker monotherapy in Chinese Han AS patients. Duration of disease, erythrocyte sedimentation rate, and c-reactive protein serum levels were found to be associated with increased adverse events with anti-TNF-α therapy. Long-term treatment with Infliximab was associated with more adverse events than rhTNFR-Fc.

Serum C-reactive protein and CRP genotype in pediatric inflammatory bowel disease: influence on phenotype, natural history, and response to therapy

BACKGROUND

C-reactive protein (CRP) is an acute phase reactant. Patients with pediatric inflammatory bowel disease (PIBD) differ from adult patients with inflammatory bowel disease with regard to phenotype, inflammatory profile, and treatment response. We hypothesized that variations in CRP and CRP genotype influence PIBD phenotype, natural history, and remission after anti-tumor necrosis factor alpha therapy.

METHODS

Six single nucleotide polymorphisms tagging CRP (rs1935193, rs1130864, rs1205, rs1417938, rs11265263, and rs1800947) were genotyped in 465 patients with PIBD (diagnosed <17 yr). Phenotyping was serially performed until last follow-up and serum CRP levels recorded at diagnosis and before biological therapy in a subgroup.

RESULTS

CRP haplotype (ATGCTC) differed in those diagnosed <10 years, with rs1205T more frequent in Crohn's disease (CD) than ulcerative colitis (UC) (P = 0.009); the haplotype ATGCTC was less frequent in UC (P = 0.002). Three single nucleotide polymorphisms (rs1205, rs1130864, and rs1417938) showed association with elevated CRP levels at diagnosis. CRP genotype had no association with CD phenotype or natural history. CRP was more frequently raised at diagnosis in CD than UC (63% versus 22%, P < 0.0001). Elevated CRP at diagnosis was associated with a higher risk of progression to surgery in patients with CD (P < 0.0001) and the need for azathioprine in the overall PIBD cohort (P = 0.002). There was no effect of CRP genotype or serum CRP on the achievement of remission using anti-tumor necrosis factor alpha therapy.

CONCLUSIONS

CRP and CRP genotype differ between pediatric patients with CD and UC with a high inflammatory burden at diagnosis suggesting a worse prognosis. Additional evaluation of CRP in inflammatory bowel disease pathogenesis and natural history is now warranted.

CRP 1059 G/C and 1846G/A polymorphisms and cancer risk: a meta-analysis of 26,634 subjects

BACKGROUND AND OBJECTIVE

Previous studies have shown that C-reactive protein (CRP) 1059G/C and 1846G/A polymorphisms may play a role in cancer risk. However, the results from the published studies are conflicting. To derive a more precise estimation of the relationship between CRP 1059G/C and 1846G/A polymorphisms and cancer risk, we conducted a meta-analysis of 21 studies involving a total of 26,634 subjects.

METHODS

Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association.

RESULTS

No significant association was found between CRP 1846G/A polymorphism and cancer risk. However, a significant association was found between CRP 1059G/C polymorphism and cancer risk (CC vs CG+GG: OR=3.60, 95% CI=1.63-7.92, PH=0.67; CC vs GG: OR=3.53, 95% CI=1.60-7.77, PH=0.69). In the subgroup analysis by ethnicity, a significant association was found for the CRP 1846G/A polymorphism among mixed population. Interestingly, when stratifying by cancer type, marginally increased risks were observed for CRP 1846G/A polymorphism in colorectal cancer (AA vs AG+GG: OR=1.17, 95% CI=1.00-1.36, PH=0.27) and significantly decreased risks were found for CRP 1846G/A polymorphism in breast cancer (AA vs GG: OR=0.73, 95% CI=0.56-0.95, PH=0.93; A vs G: OR=0.88, 95% CI=0.79-0.99, PH=0.54). For 1059G/C polymorphism, a significant association was found in colorectal cancer.

CONCLUSION

This meta-analysis showed the evidence that CRP 1059G/C and 1846G/A polymorphisms were risk factors for the development of colorectal cancer, and CRP 1846G/A polymorphism is also a protective factor for decreasing breast cancer.

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.

C-reactive protein and lung diseases

C-reactive protein (CRP), a member of the pentraxin family of plasma proteins, is one of the most distinctive acute phase reactants. In response to inflammation, cell damage or tissue injury, plasma level of CRP rapidly and dramatically increases up to 1000-fold, a phenomenon that has been used for years to monitor infections and many destructive/inflammatory conditions. The magnitude of CRP increase usually correlates with the severity of injury or inflammation and reflects an important physiological role of this interesting but still under-investigated protein. It is now generally accepted that CRP is involved in host defense and inflammation. However, the exact function of this protein in health and disease remains unclear. Many studies have demonstrated that in different pathophysiological conditions CRP might be involved in the regulation of lung function and may participate in the pathogenesis of various pulmonary disorders. The fluctuation of CRP concentrations in both alveolar fluid and serum associated with different pulmonary diseases suggests its important role in lung biology. Discussion of the still controversial functions of CRP in lung physiology and diseases is the main focus of this review.

Breaking immunological tolerance in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a fairly heterogeneous autoimmune disease of unknown etiology that mainly affects women in the childbearing age. SLE is a prototype type III hypersensitivity reaction in which immune complex depositions cause inflammation and tissue damage in multiple organs. Two distinct cell death pathways, apoptosis and NETosis, gained a great deal of interest among scientists, since both processes seem to be deregulated in SLE. There is growing evidence that histone modifications induced by these cell death pathways exert a central role in the induction of autoimmunity. In the current review, we discuss how abnormalities in apoptosis, NETosis, and histone modifications may lead to a break of immunological tolerance in SLE.

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.

Sex Differences in monocytes and TLR4 associated immune responses; implications for systemic lupus erythematosus (SLE)

It has been shown that TLR7 and TLR9 signaling play a role in SLE pathogenesis. Our recent study revealed that estrogen receptor α knockout mice have impaired inflammatory responses to TLR3, TLR4, TLR7 and TLR9 ligand stimulation in DCs, B cells and whole spleen cells. These findings indicate that estrogen receptor mediated signaling may impact universal TLR responsiveness. Whether estrogen has a direct or indirect effect on TLR responsiveness by immune cells is not clear. There is evidence of a role of TLR4 in SLE disease pathogenesis, such as the kidney damage, the induction of CD40 and autoantibodies, the suppression of regulatory T cells, and the role of pro-inflammatory cytokines (e.g., IL-6, IL-1β, TNF-α) in SLE pathogenesis that can be induced by TLR4-mediated monocyte activation, suggesting that TLR4 and TLR4 responsiveness are also important for SLE disease. This review will focus on TLR4 responses and monocytes, which are understudied in systemic autoimmune diseases such as SLE.

Decreased apopto-phagocytic gene expression in the macrophages of systemic lupus erythematosus patients

The clearance of apoptotic cells has an important role in the maintenance of tissue homeostasis and in the protection of tissues from the inflammatory and immunogenic contents of dying cells. A defect in the recognition and phagocytosis of apoptotic cells contributes to the development of chronic inflammation and autoimmune disorders. We have observed that compared with healthy donors, differentiated macrophages from patients with untreated systemic lupus erythematosus (SLE) showed decreased phagocytosis of apoptotic neutrophils. A TaqMan Low Density Array was designed to determine the mRNA expression levels of 95 apopto-phagocytic genes in differentiated non-phagocytosing and phagocytosing macrophages. In the macrophages of clinically and immunoserologically active SLE patients, 39 genes were expressed at lower levels than in the control macrophages. When inactive patients were compared with those with minor immunoserological abnormalities or patients in an immunoserologically active state, a relationship was observed between the altered gene expression profile and the disease state. In the macrophages of patients with engulfing apoptotic cells, an upregulation of genes involved in inflammation, autophagy, and signaling was observed. These results indicate that novel immune-pathological pathways are involved in SLE and suggest targets for potential therapeutic modulation.

Pentraxins: structure, function, and role in inflammation

The pentraxins are an ancient family of proteins with a unique architecture found as far back in evolution as the Horseshoe crab. In humans the two members of this family are C-reactive protein and serum amyloid P. Pentraxins are defined by their sequence homology, their pentameric structure and their calcium-dependent binding to their ligands. Pentraxins function as soluble pattern recognition molecules and one of the earliest and most important roles for these proteins is host defense primarily against pathogenic bacteria. They function as opsonins for pathogens through activation of the complement pathway and through binding to Fc gamma receptors. Pentraxins also recognize membrane phospholipids and nuclear components exposed on or released by damaged cells. CRP has a specific interaction with small nuclear ribonucleoproteins whereas SAP is a major recognition molecule for DNA, two nuclear autoantigens. Studies in autoimmune and inflammatory disease models suggest that pentraxins interact with macrophage Fc receptors to regulate the inflammatory response. Because CRP is a strong acute phase reactant it is widely used as a marker of inflammation and infection.

C-reactive protein inhibits plasmacytoid dendritic cell interferon responses to autoantibody immune complexes

OBJECTIVE

C-reactive protein (CRP) is a serum pattern recognition molecule that binds to apoptotic cells and nucleoprotein autoantigens and Fcγ receptors (FcγR). In systemic lupus erythematosus (SLE), immune complexes (ICs) containing nucleoprotein autoantigens activate plasmacytoid dendritic cells (PDCs) to produce type I interferon (IFN), which contributes to disease pathogenesis. Autoantibody ICs are taken up by PDCs through FcγR type IIa into endosomes, where the nucleic acid components activate Toll-like receptor 7 (TLR-7) or TLR-9. The objective of this study was to investigate the effect of CRP on PDC and monocyte responses to nucleoprotein autoantigens and ICs.

METHODS

Peripheral blood mononuclear cells (PBMCs), purified monocytes, and PDCs were isolated from healthy volunteers and stimulated with autoantibody ICs containing apoptotic cells, small nuclear RNPs (snRNPs), or DNA, or directly with TLR-7 and TLR-9 agonists. Supernatants were analyzed for IFNα and cytokine levels by enzyme-linked immunosorbent assay and multiplex assay. Small nuclear RNPs were fluorescence-labeled, and the effect of CRP on binding, uptake, and intracellular localization of autoantibody snRNP complexes was measured by flow cytometry and confocal microscopy.

RESULTS

CRP bound to autoantigen did not induce IFNα in PBMCs or PDCs, whereas complexes formed with autoantibody did. Significantly, CRP inhibited the IFNα response to both anti-U1 RNP-snRNP complexes and anti-DNA-DNA complexes, but not to other TLR-7 and TLR-9 agonists. CRP directly inhibited PDC IFNα release, promoted PDC differentiation, and increased late endosome localization of autoantigen in PDCs and monocytes.

CONCLUSION

CRP is a regulator of the type I IFN response to SLE ICs. CRP increased the intracellular processing of ICs in late endosomes, which is associated with decreased synthesis of type I IFN after intracellular TLR activation.

Decreased ITGAM and FcγRIIIA mRNA expression levels in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with complex genetic predisposing factors involved. ITGAM and FCγRIIIA are two kinds of immune complex clearance molecules. The variants in ITGAM and FCγRIIIA genes have been confirmed to be associated with SLE. The aim of this study is to investigate the association of mRNA expression levels of ITGAM and FCγRIIIA with SLE. Real-time transcription-polymerase chain reaction analysis (RT-PCR) was used to determine the expression levels of ITGAM and FCγRIIIA mRNA in peripheral blood mononuclear cells (PBMC) from 60 patients with SLE and 60 healthy controls. Flow cytometry was used to measure the expression level of ITGAM and FcγRIIIA from 30 SLE patients and 30 healthy controls. The expression levels of ITGAM mRNA was significantly decreased in SLE patients compared with healthy controls (P = 0.007). Patients with arthritis had higher ITGAM mRNA level than those without arthritis (P = 0.029). The expression level of FCγRIIIA mRNA in SLE patients was significantly lower than that of healthy controls (P = 0.001). Decreased expression level of FCγRIIIA mRNA was also found in patients with LN compared with those without LN (P = 0.015). The level of ITGAM mRNA in patients with anti-SSB positive, anti-RNP positive, complement reduction and increased IgG was significantly reduced. No significant correlation was found between ITGAM and FcγRIIIA mRNA expression level in SLE patients (r = -0.019, P = 0.882). Expression of ITGAM protein in T cells, neutrophil and monocyte of SLE patients was significantly lower than healthy controls (P < 0.05). For FcγRIIIA protein expression in monocyte and NK cells, there were no significant difference between SLE patients and healthy controls (P > 0.05). The altered expression levels of ITGAM and FCγRIIIA mRNA in SLE patients and their correlations with clinical data suggest that ITGAM and FCγRIIIA may play a role in this disease.

High-sensitivity C-reactive protein, disease activity, and cardiovascular risk factors in systemic lupus erythematosus

OBJECTIVE

To study the level of high-sensitivity C-reactive protein (hsCRP) and its relationship with disease activity, damage, and cardiovascular risk factors in patients with systemic lupus erythematosus (SLE).

METHODS

Consecutive patients who fulfilled ≥4 American College of Rheumatology criteria for SLE who did not have a concurrent infection were recruited. Blood was assayed for hsCRP level, and disease activity, organ damage of SLE, and cardiovascular risk factors were assessed. Linear regression analyses were performed for the relationship between hsCRP levels, SLE activity, damage, and cardiovascular risk factors.

RESULTS

In total, 289 patients were studied (94% women, mean ± SD age 39.0 ± 13.1 years, and mean ± SD SLE duration 7.8 ± 6.7 years). The mean ± SD Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score was 4.9 ± 5.6 and clinically active SLE was present in 122 patients (42%). The mean ± SD hsCRP level was 4.87 ± 12.7 mg/liter, and 28 patients with active SLE (23%) had an undetectable hsCRP level (<0.3 mg/liter). The linear regression analyses revealed a significant correlation between hsCRP level and musculoskeletal disease (β = 0.21), hematologic disease (β = 0.19), active serositis (β = 0.46), and clinical SLEDAI score (β = 0.24) after adjusting for age, sex, body mass index, serum creatinine, and the use of various medications (P < 0.005 for all). hsCRP levels correlated significantly with anti-double-stranded DNA titer (β = 0.33, P < 0.001) but did not correlate with complement C3 (β = -0.07, P = 0.26). An hsCRP level >3 mg/liter was significantly associated with male sex, long-term smoking, diabetes mellitus, a higher atherogenic index, and a history of arterial thrombosis. hsCRP levels correlated significantly with pulmonary and endocrine damage scores.

CONCLUSION

hsCRP was detectable in 77% of SLE patients with clinically active disease and correlated with SLEDAI scores, particularly in serositis and in the musculoskeletal and hematologic systems. Elevated hsCRP levels in SLE were associated with certain cardiovascular risk factors and a history of arterial thromboembolism.

Association study of CRP gene in systemic sclerosis in European Caucasian population

Opsonization and apoptotic cell elements are critical in systemic lupus erythematosus (SLE) and could act through the activation of the innate immunity. C-reactive protein (CRP) belongs to opsonins, and polymorphisms of CRP gene have been shown to be associated with SLE susceptibility. Accumulating evidences show that SLE and systemic sclerosis (SSc) share some genetic susceptibility factors. To determine whether polymorphisms of CRP confer susceptibility to SSc, four SNPs (rs1130864, rs1205, rs1800947 and rs1341665), chosen using Hapmap linkage disequilibrium data and published data, were genotyped in a cohort of 651 SSc patients (569 with antinuclear antibodies, 258 with anti-centromere and 153 with anti-topoisomerase I) and 442 controls. All individuals were of French Caucasian origin. The four polymorphisms were in Hardy-Weinberg equilibrium in the control population. Allelic and genotypic frequencies for these four polymorphisms were found to be similar in SSc patients and controls. Moreover, subphenotype analyses in particular for subgroups having antinuclear antibodies did not detect any difference between SSc patients and controls. These results obtained through a large cohort of European Caucasian SSc patients do not support the implication of CRP gene in the pathogenesis of SSc.