A time-resolved immunofluorometric assay for porcine C-reactive protein quantification in whole blood.

A time-resolved immunofluorometric assay (TR-IFMA) for C-reactive protein (CRP) determination in whole blood of pigs was developed and validated. CRP was isolated from porcine acute-phase serum by affinity chromatography on agarose, coupled with phosphorylethanolamine and polyclonal antibodies to porcine CRP were purified from antiserum raised in sheep immunized with porcine CRP. Intra- and inter-assay coefficients of variation (CVs) were in the range 3.13-7.19% and 7.06-15.66%, respectively, showing good precision. The assay measured the CRP values in a proportional and linear manner (r=0.99); additionally, CRP concentrations measured in whole blood by the present TR-IFMA and in serum by an established immunoturbidimetric assay were highly correlated (R(2)=0.97). The limit of detection of the method was 0.0028 mg/L. Significantly lower CRP concentrations were observed after 7 days of sample storage at 4 degrees C. The injection of turpentine oil caused a significant increase in CRP concentrations and significantly higher CRP concentrations were observed in pigs with pathological processes compared to healthy animals.     

CRP determination based on a novel magnetic biosensor

The c-reactive protein (CRP) is a very significant human blood marker for inflammatory processes and is routinely determined for many clinical purposes. The widespread and well established detection method for this approximately 115 kDa hepatic protein is the high-sensitivity ELISA assay (hsCRP-ELISA) in blood serum. New approaches in medical CRP diagnosis (e.g. for CVD, inflammatory bowel disease) require rapid quantification in native matrices. A novel CRP determination method based on magnetic detection is described and tested for human blood serum, saliva and urine. The detection principle is based on two different anti-CRP antibodies (monoclonal, IgG) for CRP trapment and labelling. The linear detection range of this immunosensor ranged from 25 ng/ml to 2.5 microg/ml and is therefore much more sensitive than typical hsCRP-ELISA-assays.     

SPR-based immunosensor for the CRP detection--a new method to detect a well known protein

The c-reactive protein (CRP) is one of the significant human blood serum markers for inflammatory processes. The serum presence of this hepatic approximately 115 kDa protein of five identical subunits accompanies several diseases (e.g. CVD, inflammatory bowel diseases) and is nowadays detected by high-sensitivity ELISA assays in blood serum. To enable CRP detection in other matrices, an SPR-based (surface plasmon resonance) immunosensor for the CRP detection has been established. A linear detection range of 2-5 microg CRP per ml was found, using two different antiCRP antibodies (monoclonal, IgG) for CRP trapment and detection. Furthermore, the kinetic antibody association and dissociation constants of one antibody (antiCRP, clone C2) could be determined.     

Quantitative detection of C-reactive protein using phosphocholine-labelled enzyme or microspheres

C-reactive protein (CRP) is a positive, acute-phase protein. Plasma levels rise dramatically in response to tissue injury or inflammation and fall rapidly after recovery or treatment. Antibody-based human CRP test systems do not readily detect CRP from other animals due to the species specificity of antibodies directed against human CRP. Thus, generic systems for CRP detection, based solely on the interaction between CRP and phosphocholine (PC), have been developed. PC-bovine serum albumin (PC-BSA) conjugates were produced and either labeled with horseradish peroxidase to facilitate CRP detection in a CRP enzyme-linked sorbent assay (ELSA) or coupled to carboxy-modified microspheres to facilitate the nonenzymatic, turbidimetric detection of CRP. The CRP-ELSA is a competitive assay, where the total assay time is 45 min, the assay sensitivity is 1.06 mg/L CRP, and the dynamic range of the assay is 0-500 mg/L. When PC-BSA conjugate is covalently coupled to carboxylated microspheres, agglutination occurs in the presence of CRP, the extent of which depends on the quantity of CRP present in the sample. Total assay time is 5 min with a dynamic range of 25-500 mg/L. Both assay formats are capable of accurately detecting human CRP and the CRP-ELSA can detect canine CRP as a disease state indicator.     

Sensitive detection of cardiac biomarker using ZnS nanoparticles as novel signal transducers

C-reactive protein (CRP), a 115 kDa pentameric protein, is one of the important cardiac biomarkers that are indicative of coronary heart events. Sensitive detection of CRP in human serum is critical for the diagnosis of coronary heart disease. This work presents a sensitive sandwich immunoassay for the detection of CRP in human serum using zinc sulfide (ZnS) nanoparticles as novel fluorescence signal transducers. In this assay, monoclonal anti-CRP antibodies are used to capture CRP in human serum, and then the captured CRPs are incubated with biotinylated monoclonal anti-CRP and Neutravidin coated ZnS nanoparticle to form sandwich immunocomplexes. Quantification of CRP occurs when zinc ions released from ZnS nanoparticle labels are mixed with zinc-ion sensitive fluorescence indicator Fluozin-3 for fluorescence generation. The developed assay presents a detection limit around 10 pM and a detection range with more than two orders of magnitude.     

妊娠糖尿病患者血清HbA1c与CRP水平的相关性分析

目的:为明确妊娠期糖尿病(gestational diabetes mellitus,GDM)患者血清糖化血红蛋白(glycosylated hemoglobin,Hb A1c)与C反应蛋白(C-reactive protein,CRP)的关系,本研究检测了GDM患者血糖、血清Hb A1c与CRP水平,并对Hb A1c与CRP的相关性进行了分析。方法:以68例2015年4月至2017年4月于我院诊治的GDM孕妇为研究对象,所有患者均符合《妇产科学》中关于GDM的诊断标准,另选取68例正常孕妇为对照组。采用葡萄糖氧化酶法检测血糖水平(空腹血糖及餐后2 h血糖水平),采用免疫凝集法检测和比较两组血清糖化血红蛋白(HbA1c)水平,采用免疫透射比浊法检测血清C反应蛋白(CRP)水平,并分析HbA1c与CRP的相关性。结果:GDM组患者空腹血糖(fasting plasma glucose,FPG)、2 h血糖(plasma glucose,PG)、血清HbA1c和CRP水平均显著高于正常组(P0.05),GDM患者血清Hb A1c和CRP水平呈显著正相关关系(r=0.654,P0.05)。结论:GDM患者血清HbAlC和CRP水平相较于正常孕妇有显著提高,且二者呈显著的正相关关系,二者联合检测可能作为GDM早期诊断的筛查的重要参考指标。     

Serum C-reactive protein (CRP) levels and insulin resistance in non-obese women with polycystic ovarian syndrome, and effect of bicalutamide on hirsutism, CRP levels and insulin resistance

BACKGROUND/AIMS: Insulin resistance is associated with serum C-reactive protein (CRP) levels. We aimed to evaluate the effect of bicalutamide on insulin resistance and serum CRP levels in non-obese polycystic ovarian syndrome (PCOS) patients. METHODS: 40 non-obese patients (BMI < or =25 kg/m2) with PCOS and, 40 age- and BMI-matched healthy women were studied. Patients received bicalutamide orally at the dose of 25 mg/day. Serum CRP levels were measured with immunometric assay. Homeostasis model assessment (HOMA-IR) index was used for insulin resistance. RESULTS: Mean Ferriman-Gallwey score (FGS) (p = 0.001), insulin (p = 0.001), serum glucose (p = 0.001), prolactin (p < 0.003), total (p < 0.04) and free testosterone (p = 0.001) and free androgen index (FAI) levels (p = 0.001) of PCOS subjects were higher than in the control group. Mean HOMA-IR of PCOS patients was higher than in control subjects (2.43 +/- 1.2 and 0.94 +/- 0.37, p = 0.001). CRP levels in subjects with PCOS was also higher than in control subjects (4.27 +/- 1.33 and 0.98 +/- 0.19, p = 0.001). After bicalutamide treatment, FGS, free and total testosterone and FAI decreased (p = 0.001). HOMA-IR, prolactin and CRP levels did not show any statistical difference with bicalutamide treatment. CONCLUSIONS: PCOS patients had insulin resistance and a high CRP level. Bicalutamide treatment did not influence insulin resistance and CRP level in PCOS, and this ineffectiveness of bicalutamide on CRP levels may be the result of insulin resistance and/or high prolactin levels at this time.     

One-step kinetics-based immunoassay for the highly sensitive detection of C-reactive protein in less than 30 min

This article reveals a rapid sandwich enzyme-linked immunosorbent assay (ELISA) for the highly sensitive detection of human C-reactive protein (CRP) in less than 30 min. It employs a one-step kinetics-based highly simplified and cost-effective sandwich ELISA procedure with minimal process steps. The procedure involves the formation of a sandwich immune complex on capture anti-human CRP antibody-bound Dynabeads in 15 min, followed by two magnet-assisted washings and one enzymatic reaction. The developed sandwich ELISA detects CRP in the dynamic range of 0.3 to 81 ng ml⁻¹ with a limit of detection of 0.4 ng ml⁻¹ and an analytical sensitivity of 0.7 ng ml⁻¹. It detects CRP spiked in diluted human whole blood and serum with high analytical precision, as confirmed by conventional sandwich ELISA. Moreover, the results of the developed ELISA for the determination of CRP in the ethylenediaminetetraacetic acid plasma samples of patients are in good agreement with those obtained by the conventional ELISA. The developed immunoassay has immense potential for the development of rapid and cost-effective in vitro diagnostic kits.     

Common variants in the CRP gene are associated with serum C-reactive protein levels and body mass index in healthy individuals in Mexico

Variants in the C-reactive protein (CRP) gene have been found to be associated with various phenotypic traits. We evaluated the effect of four SNPs in the CRP gene on serum levels of protein and body mass index (BMI) in 150 unrelated Mexican subjects from 18 to 25 years old, without hypertension, non-overweight, and without inflammatory diseases, non-smoking and non-consumers of alcohol. Subjects were measured for BMI, waist circumference, blood pressure, and serum glucose and triglycerides. The identification of SNPs was performed by PCR-RFLP. Three of the four SNPs were associated with variation in serum levels of CRP, increased in TT (rs1130864) and GG (rs2794521) genotypes, and decreased in the AA genotype of rs1205. The TT genotype was associated with a significant increase in BMI (β = 1.1 kg/m(2), P = 0.04). Two haplotypes were significantly associated with increased serum levels of CRP, but not with BMI. We conclude that variation in the CRP gene affects serum protein levels.     

手足口病合并脑炎患儿外周血T淋巴细胞亚群、血清VCAM-1及CRP的表达水平及其检测价值分析

摘要 目的：探讨与分析手足口病（HFMD）合并脑炎患儿外周血T淋巴细胞亚群、血清VCAM-1及CRP的表达水平及其检测价值。方法：2017年4月到2020年10月选择在本院诊治的手足口病合并脑炎患儿42例作为合并组,同期选择手足口病不合并脑炎患儿68例作为对照组,检测两组外周血T淋巴细胞亚群、血清血管细胞粘附分子-1（VCAM-）及C-反应蛋白（CRP）表达水平,并判断检测价值与进行相关性分析。结果：合并组的CD4⁺、CD8⁺T淋巴细胞相对比例都明显少于对照组（P<0.05）。合并组的血清VCAM-1及CRP含量明显高于对照组（P<0.05）。在80例患儿中,Spearsman分析显示CD4⁺、CD8⁺T淋巴细胞相对比例和血清VCAM-1、CRP含量都与手足口病合并脑炎的发生存在相关性（P<0.05）。二分类Logistic回归分析显示CD4⁺、CD8⁺T淋巴细胞相对比例和血清VCAM-1、CRP含量都为导致手足口病合并脑炎发生的重要因素（P<0.05）。结论：手足口病合并脑炎患儿多伴随有外周血T淋巴细胞亚群异常与血清VCAM-1、CRP的高表达,CD4⁺、CD8⁺T淋巴细胞相对比例、血清VCAM-1、CRP含量都为导致手足口病合并脑炎发生的重要因素。     

Altered serum and salivary C-reactive protein levels in patients with oral premalignant lesions and oral squamous cell carcinoma

Chronic inflammation is associated with cancer development. C-reactive protein (CRP), an acute phase protein synthesized primarily in the liver, is a marker for inflammation and for the progression of many cancers. We compared serum and salivary CRP levels in 20 normal individuals, 20 patients with oral premalignant lesions and 20 patients with oral squamous cell carcinoma (OSCC) to assess its efficacy as a prognostic indicator for OSCC. Saliva and blood samples were obtained and evaluated for CRP levels. Mean CRP levels were higher in patients with oral premalignant lesions compared to controls. CRP levels in OSCC patients were elevated and were associated with advanced tumor stages.     

Maternal and cord blood levels of serum amyloid A, C-reactive protein, tumor necrosis factor-alpha, interleukin-1beta, and interleukin-8 during and after delivery

C-reactive protein (CRP) and serum amyloid A (SAA) are acute-phase proteins mainly synthesized by the liver in response to some cytokines. They are potentially useful to diagnosing infection and monitoring different clinical conditions. The aim of this study was to measure SAA and CRP in maternal and cord blood during and after delivery and try to correlate these proteins with tumor necrosis factor-alpha, interleukin-1beta, and interleukin-8. Acute-phase proteins and cytokines were measured by ELISA in 24 healthy pregnant women undergoing vaginal delivery or Cesarean section. Cord blood samples in addition to maternal blood were collected. SAA and CRP reached the maximum maternal serum levels 24 hours after delivery, while cytokines remained constant over time. SAA and CRP were significantly higher in maternal serum than in newborn's (P< .001) at the moment of delivery. SAA and CRP, regardless of the type of delivery, reproduce the common pattern observed in most inflammatory conditions. Proinflammatory cytokine serum levels do not mirror the increase in SAA and CRP levels.     

Association of C-reactive Protein and Circulating Leukocytes with Resistance to Staphylococcus aureus Infection in Endotoxin-treated Mice and Rabbits

The response of rabbits and mice to treatment with Escherichia coli endotoxin, as measured by C-reactive protein (CRP) and leukocyte levels, and resistance to Staphylococcus aureus infection was studied to evaluate the significance of these responses and their associations. In both species, there was an initial leukopenia without early recovery of normal lymphocyte levels. This was followed by an increase in polymorphonuclear leukocytes and a return to near the normal range. The CRP level was slightly altered during the stage of decreased resistance and increased throughout the remainder of the period of observation. The resistance level was decreased initially, recovered to normal levels, and continued to increase. The changes in CRP and resistance levels were closely associated. It would appear that this association between CRP and resistance, the antibacterial activity of CRP, and its action on the polysaccharides obtained from bacterial cell walls are evidence for the participation of CRP in nonspecific resistance to infection.     

Evaluation of a high-affinity QCM immunosensor using antibody fragmentation and 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer

This study evaluated construction of a highly affinitive quartz crystal microbalance (QCM) immunosensor using anti-C-reactive protein (CRP) antibody and its fragments for CRP detection. Three types of antibody were immobilized on the surface of a QCM via covalent-bounding. Then affinity was evaluated through antigen-antibody binding between CRP and its antibody. Affinity between antigen-antibody was shown to be highest when anti-CRP F(ab')2-IgG antibody (70 microg/mL) was immobilized on the QCM. In case of anti-CRP F(ab')2-IgG antibody, affinity which was attributable to antigen-antibody binding was almost twice that of anti-CRP IgG antibody, which is used conventionally for QCM immunosensors. In addition, when it was treated with 2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate, so-called MPC polymer, highly affinitive and selective immunosensing for CRP was achieved without non-specific binding from plasma proteins in human serum. When anti-CRP F(ab')2-IgG antibody was immobilized on the QCM, the detection limit and the linearity of CRP calibration curve were achieved at concentrations from 0.001 to 100 microg/dL even during investigation in serum samples. Experimental results verified the successful construction of a highly affinitive and selective QCM-immunosensor which was modified with anti-CRP F(ab')2-IgG antibody and MPC polymer.     

C‐reactive protein in blood plasma and serum samples of harbor seals (Phoca vitulina)

C‐reactive protein (CRP) belongs to the acute phase proteins. Increased levels are present in inflammatory conditions, trauma, or intoxications. In veterinary medicine CRP is used as powerful diagnostic parameter in health studies, whereas little is known about the role of CRP in Pinnipedia. Therefore, samples were collected from 131 harbor seals from the North Sea between November 2002 and November 2007. CRP blood values were measured and the physiological range was calculated. Furthermore, the influence of age and sex of the animal, geographical location and season was investigated. The CRP concentrations in plasma/serum showed a median of 33 μg/mL, a 5th percentile of 18 μg/mL, and a 95th percentile of 80 μg/mL. No significant influences of sex, season, or geographical location on CRP concentration were detected. Juveniles showed significantly higher CRP levels than adult animals, whereas CRP values in newborns appear to be lower than in juveniles and adults. Our report describes for the first time CRP plasma/serum concentrations in a large group of harbor seals. It suggests that CRP is useful to detect inflammatory conditions and may help to improve health studies of this species.     

阿托伐他汀对大脑中动脉支架置入后患者血脂、血清CRP及脑缺血性不良事件的影响

目的:探讨阿托伐他汀对大脑中动脉支架置入后患者血脂、血清C-反应蛋白(CRP)及脑缺血性不良事件的影响。方法:选择本院收治的60例行大脑中动脉支架置入术后的患者,采用随机序号的方式将其分为观察组和对照组各30例,其中对照组给予口服拜阿司匹林和硫酸氢氯吡格雷进行治疗,观察组在对照组基础上加服阿托伐他汀进行治疗,对两组治疗后6个月、12个月时患者血脂、血清C-反应蛋白(CRP)及脑缺血性不良事件发生率进行对比分析。结果:观察组在治疗后6个月时LDL-C、TC、TG及CRP含量与治疗前和对照组比较显著下降,比较差异均有统计学意义(P0.05);观察组患者在治疗后的12个月时LDL-C、TC、TG及CRP含量亦明显低于治疗前和对照组,比较差异均有统计学意义(P0.05);观察组不良事件发生率为10%,明显低于对照组不良事件发生率的30%,两组比较差异有统计学意义(P0.05)。结论:阿托伐他汀对不仅可有效改善大脑中动脉支架置入术后患者的血脂、血清C-反应蛋白(CRP)的各项指标水平,而且还能有效的降低脑缺血性不良事件的发生。     

Development of a bead-based aptamer/antibody detection system for C-reactive protein

A multiplexing bead-based platform provides an approach for the development of assays targeting specific analytes for biomonitoring and biosensing applications. Multi-Analyte Profiling (xMAP) assays typically employ a sandwich-type format using antibodies for the capture and detection of analytes of interest, and the system permits the simultaneous quantitation of multiple targets. In this study, an aptamer/antibody assay for the detection of C-reactive protein (CRP) was developed. CRP is an acute phase marker of inflammation whose elevated basal levels are correlated with an increased risk for a number of pathologies. For this assay, an RNA aptamer that binds CRP was conjugated to beads to act as the capture agent. Biotinylated anti-CRP antibody coupled to fluorescently labeled streptavidin was used for quantification of CRP. The detection limit of the CRP assay was 0.4 mg/L in diluted serum. The assay was then used to detect spiked CRP samples in the range of 0.4 to 10 mg/L in diluted serum with acceptable recoveries (extrapolated values of 70–130%), including that of a certified reference material (129% recovery). The successful incorporation of the CRP aptamer into this platform demonstrates that the exploration of other aptamer–target systems could increase the number of analytes measurable using xMAP-type assays.     

血清PCT、CRP及IL-6联合检测诊断细菌性血流感染的临床价值分析

目的:探讨血清降钙素原(PCT)、C反应蛋白(CRP)及白介素-6(IL-6)联合检测诊断细菌性血流感染(BSI)的临床价值。方法:选取我院2015年8月到2016年10月收治的疑似细菌性BSI患者216例,入院后均送检血培养,根据培养结果将其分为阳性组(102例)和阴性组(114例)。统计细菌性BSI阳性率、革兰阳性菌感染率和革兰阴性菌感染率;检测血清PCT、CRP、IL-6水平,并比较两组患者的差异,同时绘制ROC曲线并计算出各指标及联合检测的灵敏度、特异度、阳性预测值、阴性预测值及约登指数值。结果:所有疑似BSI患者的细菌阳性检出率为47.22%,革兰阳性菌感染率与革兰阴性菌感染率对比无差异(P0.05);阳性组的血清PCT、CRP、IL-6水平均明显高于阴性组(P0.05);血清IL-6的AUC明显大于PCT和CRP(P0.05);PCT、CRP及IL-6联合检测的灵敏度、特异度、阳性预测值、阴性预测值及约登指数均明显高于单项检测(P0.05)。结论:血清PCT、CRP及IL-6对于BSI均有着一定诊断价值,而各指标联合检测诊断BSI的临床价值更高。     

血清sPLA2-X、8-羟基-2'-脱氧鸟苷及hs-CRP水平诊断慢性阻塞性肺疾病急性加重的价值

摘要 目的：探究血清sPLA2-X、8-羟基-2''-脱氧鸟苷及hs-CRP水平诊断慢性阻塞性肺疾病急性加重的价值。方法：随机选取2021年3月~2023年11月在我院进行治疗的COPD患者128例,以患者是否出现急性加重分为稳定组和AECOPD组,其中稳定组29例,AECOPD组99例。比较两组研究对象外周血sPLA2-X、8-OHdG及hs-CRP水平水平差异;COX比例风险因素回归模型分析AECOPD的影响因素,采用ROC曲线分析相关指标单独及联合检测诊断AECOPD的价值。结果：AECOPD组FEV₁指标显著低于稳定组,差异具有统计学意义（P<0.05）。与稳定组组相比,AECOPD组患者外周血sPLA2-X、8-OHdG及hs-CRP水平均明显升高,差异具有统计学意义（P<0.01）。外周血sPLA2-X、8-OhdG、hs-CRP水平与GOLD分级成正相关（P<0.05）,外周血sPLA2-X、8-OhdG、hs-CRP水平与FEV₁/FVC（%）、FEV₁%pred成负相关（P<0.05）。采用COX比例风险因素回归模型分析,外周血sPLA2-X、8-OhdG、hs-CRP均为影响AECOPD的独立危险因素。ROC曲线分析外周血sPLA2-X、8-OhdG、hs-CRP诊断AECOPD的曲线下面积（AUC）分别为0.689、0.708、0.642、0.875,联合各指标预测价值明显高于单独检测。结论：AECOPD 患者外周血sPLA2-X、8-OhdG、hs-CRP水平高表达。外周血sPLA2-X、8-OhdG、hs-CRP水平与肺功能严重程度、肺功能指标相关,同时三者可用作诊断COPD患者急性加重的潜在预测指标。三者联合具有更高的诊断价值。     

腹部外伤患者术后感染与血清炎症因子的关联性研究

本研究旨在探讨外伤术后腹腔感染患者血清降钙素原(PCT)、肿瘤坏死因子-α(TNF-α)、C-反应蛋白(CRP)和白细胞介素6 (IL-6)的水平变化与感染程度的相关性,为外伤术后腹腔感染临床治疗、抗菌药物应用提供依据。本研究选取我院2015年1月至2017年5月收治的腹部外伤手术患者150例,其中术后发生感染患者83例,未感染组,未发生感染患者67例,为非感染组。通过检测其术前术后及进行抗感染治疗后的PCT、TNF-α、CRP、IL-6水平,对腹腔感染标本进行菌种鉴定,并分析PCT、TNF-α、CRP、IL-6水平变化与腹腔感染的相关性,本研究发现,感染组患者术后各时间段血清PCT、TNF-α、CRP、IL-6水平明显较术前升高(p<0.05);且在术后12 h、24 h、72 h的PCT、TNF-α、CRP、IL-6水平明显高于未感染组(p<0.05);感染患者标本共检出76株不同的菌株,革兰阴性杆菌45株,革兰阳性菌22株,真菌9株;PCT、TNF-α、CRP在术后12 h、24 h、72 h检出感染的阳性率与病原学诊断结果相关性较高,血清IL-6则在术后72 h检出感染的阳性与病原学诊断相关性较高。本研究初步得出结论,临床检测血清PCT、TNF-α、CRP和IL-6均有助于鉴别是否存在外科腹腔感染,对抗菌药物的应用有一定的指导作用。