Comparative study of two automated high-sensitivity C-reactive protein methods in a large population

OBJECTIVES: Increased serum C-reactive protein (CRP) is associated with future risk of coronary heart disease in apparently healthy individuals. Numerous high-sensitivity CRP (hs-CRP) methods are available but their comparability in large populations has not been assessed. This study aimed to evaluate the performance of two CRP methods in a large Asian population. DESIGN AND METHODS: We compared the Tina-quant CRP immunoturbidimetric assay (Roche COBAS INTEGRA) to the N high-sensitivity latex-enhanced immunonephelometric (BN 100 nephelometer, Dade Behring) assay using 4118 serum samples from the International Collaborative Study on Atherosclerosis and Stroke in Asia (Inter ASIA). RESULTS: The median hs-CRP value for the N high-sensitivity CRP method (1.23 mg/L) was significantly lower than that for the Tina-quant method (1.50 mg/L), P < 0.001. The two methods were highly associated (r = 0.9916). Deming regression analysis gave a slope of 0.958 [95% confidence interval (CI): 0.954-0.962] with an intercept of 0.280 [95% confidence interval (CI): 0.268-0.292]. The mean of the method differences was 0.19 mg/L and the limits of agreement (LOA), which encompass 95% of results, were -0.36-0.74 mg/L. We found the percentages of low, average, and high-risk results were 42.9, 33.8, and 23.3 for the N high-sensitivity CRP and 33.2, 41.1, and 25.7 for the Tina-quant method. The percentage of samples concordant by both methods was 87.4%. The Tina-quant CRP classified more subjects into the high-risk group. CONCLUSIONS: The two hs-CRP methods were highly associated and are suitable for screening large populations.     

Highly sensitive determination of C-reactive protein on the Innotrac Aio! immunoanalyzer

C-reactive protein (CRP) is a widely recognized indicator of inflammation. Prospective studies have shown that CRP can be used to predict the risk of future cardiovascular events in apparently healthy subjects. Clinical and laboratory studies have also shown that inflammation has an important role in the inititation, progression and destabilization of atheromas, which makes high-sensitivity CRP determinations valuable in cardiovascular risk assessment. Innotrac Aio! is a fully automated random-access immunoanalyzer using a unique all-in-one (Aio!) dry reagent concept and time-resolved fluorometric detection. In this study, the analytic performance of the Innotrac Aio! ultrasensitive CRP assay (usCRP) was evaluated. The analytical detection limit was 0.003 mg/L, the limit of quantification was 相似文献   

Highly sensitive determination of C-reactive protein on the Innotrac Aio! immunoanalyzer

C-reactive protein (CRP) is a widely recognized indicator of inflammation. Prospective studies have shown that CRP can be used to predict the risk of future cardiovascular events in apparently healthy subjects. Clinical and laboratory studies have also shown that inflammation has an important role in the inititation, progression and destabilization of atheromas, which makes high-sensitivity CRP determinations valuable in cardiovascular risk assessment. Innotrac Aio! is a fully automated random-access immunoanalyzer using a unique all-in-one (Aio!) dry reagent concept and time-resolved fluorometric detection. In this study, the analytic performance of the Innotrac Aio! ultrasensitive CRP assay (usCRP) was evaluated. The analytical detection limit was 0.003?mg/L, the limit of quantification was ≤?0.03?mg/L and the carry-over result was within acceptable limits. Within-assay CVs obtained in lithium-heparin plasma at five concentrations ranged within 3.2 and 24.9%. Inter-assay precision using lithium-heparin plasma pools and commercial controls was 6.2-8.6% at concentrations of 0.17-33.3?mg/L. The inter-assay precision at a concentration of 0.04?mg/L using the serum pool was 67%. Regression analysis between Aio! usCRP and Cobas Integra CRP latex (Roche Diagnostics) using lithium-heparin plasma samples yielded the following results: correlation coefficient 0.983, slope 1.17 (&;lt;50?mg/L) and correlation coefficient 0.974, slope 1.137 (&;lt;10?mg/L). The correlation coefficient between Integra and Aio! usCRP assays using serum samples was 0.979 and the slope 1.106. Regresssion analysis between Aio! usCRP and Hitachi CRP (Latex) HS using serum samples revealed the following results: correlation coefficient 0.942, slope 0.879 (&;lt;20?mg/L) and correlation coefficient 0.973, slope 0.983 (&;lt;10?mg/L). EDTA whole blood samples correlated well with the corresponding plasma samples. Innotrac Aio! usCRP assay was found to be linear in the CRP concentration range of 0.09-62?mg/L. In the first quartile (0-25th percentile), 2nd quartile (25th-50th percentile), 3rd quartile (50th-75th percentile) and 4th quartile (75th-100th percentile), the mean CRP values were 0.16?mg/L, 0.52?mg/L, 1.24?mg/L and 4.39?mg/L, respectively.     

Comparison of two methods for rapid determination of C-reactive protein with the Tina-quant

C-reactive protein (CRP) as an acute phase protein is an important diagnostic marker for the presence and course of human processes. Out of the acute phase proteins it is one of those the concentrations increase most rapidly with its sensitivity being superior to other markers of inflammation, such as leukocytosis, erythrocytic sedimentation rate, and fever. This study compared two-point-of-care assays with the standard laboratory method Tina-quant CRP processed on a Hitachi 917: the immunofiltration assay NycoCard CRP Whole Blood and the turbidimetric immunoassay Micros CRP. Both methods are carried in the presence of a patient, by using capillary or venous blood. Seventy-eight blood samples were analyzed first in the standard laboratory routine and then by both rapid test assays. The precision of both assays was determined from the confidence interval. The results were statistically analyzed by arithmetic standard deviation mean method, variation coefficient, Spearman correlation index, Wilcoxon and Bland-Altman tests, and Passing-Bablock regression. NycoCard CRP Whole Blood showed a correlation coefficient of R = 0.9838; the precision had a coefficient of variation of CV = 1.8759% while As compared with Tina-quant CRP had R = 0.9934 and CV = 0.9160%. Both assays indicated the same results as Tina-quant CRP. Both Tina-quant CRP and NycoCard CRP Whole Blood give the best fit for the rapid determination of CRP.     

Simple, sensitive measurement of carbon monoxide in plasma

A simple, sensitive method for estimating carbon monoxide in plasma is described. In this method, the carbon monoxide in plasma is trapped with hemoglobin and subsequently estimated by dithionite reduction. The method has an intra- and interassay precision (CV) of 10.7% and 12.8%, respectively, at a concentration of 1.12 mg of carbon monoxide per liter and has a detection limit of 0.1 mg/L. The reference interval for carbon monoxide in plasma from 17 men and eight women ranged from 0.14 to 0.60 mg/L (mean 0.36 mg/L).     

Comparison of ELISAs for opiates, methamphetamine, cocaine metabolite, benzodiazepines, phencyclidine, and cannabinoids in whole blood and urine

BACKGROUND: ELISAs are widely utilized in forensic drug analysis. A comparative assessment of microtiter plate assays for the detection of six common classes of drug in blood and urine is described. METHODS: ELISAs for opiates, methamphetamine, benzodiazepines, cocaine metabolite, phencyclidine (PCP), and tetrahydrocannabinol (THC) metabolite were evaluated in a side-by-side study. The analytical performance of 12 commercially available ELISAs was determined in terms of binding characteristics, dose-response curves, limits of detection, sensitivity, intra- and interassay imprecision, and lot-to-lot reproducibility. Assay performance was also compared using 855 forensic casework samples. RESULTS: Detection limits in whole blood for morphine, D-methamphetamine, nordiazepam, benzoylecgonine, nordiazepam, PCP, and L-11-nor-9-carboxy-delta9-THC were 3, 2, <4, 5, 25, and 3 microg/L, respectively, for the STC ELISAs. Corresponding detection limits for Immunalysis ELISAs were <1, <2, <4, 5, <1, and 1 microg/L, respectively. Intraassay CVs (n = 8) at the immunoassay cutoff concentrations were 4.1-5.6% and 3.5-11% for STC and Immunalysis ELISAs, respectively. Corresponding interassay CVs were 3.1-10% and 6.5-20%. Of the 855 casework samples, there were a total of 92 discordant results (44 cannabinoid, 15 opiate, 15 methamphetamine, 11 benzodiazepine, and 7 cocaine metabolite). Gas chromatography-mass spectrometry analysis indicated a total of three unconfirmed positive results for Immunalysis assays and one unconfirmed positive for STC assays. CONCLUSIONS: A comparative assessment of drugs-of-abuse assays from two manufacturers indicated some key differences in analytical performance. Overall, Immunalysis assays offered superior binding characteristics and detection limits, whereas STC assays offered improved overall precision and lot-to-lot reproducibility.     

两种检测方法测定C反应蛋白的比较

目的评估速率散射比浊法和免疫透射比浊法检测C反应蛋白(CRP)的分析性能。方法分别采用速率散射比浊法(美国Siemens Healthcare Diagnostica公司BN-Ⅱ特定蛋白仪)和免疫透射比浊法(芬兰OrionDiagnostica公司CRP快速检测仪)对CRP进行测定,方法学评价指标为精密度、线性范围、抗干扰性、相关性及偏倚。结果 CRP浓度为2.0～80.0 mg/L时,BN-Ⅱ特定蛋白仪总变异系数(CV)<6%;CRP浓度为8.0～80.0 mg/L时,CRP快速检测仪总CV<7%;检测线性范围为8.0～70.0 mg/L。血红蛋白(Hb)<10 g/L、胆红素(Bil)<300 mg/L对2种方法检测干扰<10%,在可接受范围内。甘油三酯(TG)<20 mmoL/L时BN-Ⅱ特定蛋白仪不受影响(干扰<10%)。CRP快速检测仪在TG>15 mmol/L时低值血清干扰>10%,高值血清不受干扰。50份血样相关分析的结果显示2台仪器测定结果的相关性良好(r=0.98,P<0.01)。线性回归分析经Cusum检验显示2台仪器间偏倚差异无统计学意义(P>0.05),BN-Ⅱ特定蛋白仪测定结果较CRP快速检测仪结果偏低,Bland-Altman曲线显示2种方法的平均偏倚为-2.1。结论速率散射比浊法和免疫透射比浊法的精密度、抗干扰性、线性范围符合要求。虽然系统间测定结果存在一定偏倚,但也符合临床检测要求。     

Evaluation of the high-sensitivity, full-range Olympus CRP OSR6199 application on the Olympus AU640.

BACKGROUND: Implementation of high-sensitivity C-reactive protein (hs-CRP) assays as a routine laboratory parameter may be necessary. A single CRP method giving reliable results for the whole concentration range (0.1-160 mg/L) is the most practical solution for a laboratory. The aim of this study was to assess the Olympus CRP full-range immunoturbidimetric assay on an Olympus AU640 biochemistry analyser. METHODS: CRP was determined in a population of patients simultaneously with the Randox CRP immunoturbidimetric assay and two immunonephelometric assays, the Dade Behring and Beckman Coulter CRP, on BN 100 and Immage systems, respectively. RESULTS: Analytical performance, including precision and linearity, was excellent. The correlation coefficient for linear regression was r(2)=0.998, indicating that the assay method exhibited good linearity in the working range 0-160 mg/L. The intra- and inter-assay CVs for the Olympus CRP method were <3.6% over a wide range of CRP concentrations. Linear regression analysis indicated excellent agreement between CRP values for all patients, with correlation coefficients of r(2)>0.996, 0.993 and 0.989 for the Randox, Dade Behring and Beckman methods, respectively. Bland-Altman analyses demonstrated the excellent concordance of the CRP methods for patient samples. CONCLUSIONS: This study demonstrates that the new full-range Olympus method can be applied to measure CRP as a marker of inflammation and of cardiovascular risk.     

降钙素原与C反应蛋白联合检测在细菌感染中的应用

目的评价联合检测降钙素原（PCT）、C反应蛋白（CRP）水平的改变在细菌感染患者疗效观察及预后判断中的临床意义。方法对重症监护病房（ICU）的60例细菌感染患者血清PCT、CRP的含量及动态变化进行检测,同时将60例细菌感染患者分为重症感染组和局部感染组,并与病毒感染组进行分析比较。结果重症细菌感染组血清PCT、CRP浓度中位数分别为15.0μg/L和90.0 mg/L;局部细菌感染组血清PCT、CRP中位数分别为1.8μg/L和55.3 mg/L;重症感染组和局部感染组血清PCT、CRP浓度均明显升高,与病毒感染组比较,差异有统计学意义（P〈0.001）;经有效抗菌药物治疗后,细菌感染组患者PCT、CRP水平与治疗前比较,差异有统计学意义（P〈0.001）;重症感染组与局部感染组比较,差异亦有统计学意义（P〈0.001、0.05）;以PCT〉0.5μg/L为界,诊断细菌感染的敏感性为96.7%（58/60）,特异性为85.3%（29/34）;以CRP〉8 mg/L为界,诊断细菌感染的敏感性为96.7%（58/60）,特异性为73.5%（25/34）。结论血清PCT、CRP联合检测在细菌感染的早期诊断中有一定价值,动态监测PCT水平有助于评估治疗效果,协助临床判断病情的转归和恶化。     

Measurement of C-reactive protein: two high sensitivity methods compared

C-reactive protein (CRP) is an acute phase marker and a predictor of the risk of developing atherosclerotic complications. However, as a predictor of this risk, high sensitivity measurements are needed, and high sensitive CRP (hsCRP) assays have been developed. In this study, we experimentally compared two hsCRP assays, based on nephelometry and turbidimetry, both implemented on automated analyzers. Linearity, imprecision, turbidity interference, and results in the assay of 96 samples have been compared. Method comparison of the same two analytical systems in the assay of CRP was also performed on the basis of results in an interlaboratory external quality assessment scheme (EQAS). The two systems were found to perform substantially equally, both in hsCRP and in CRP measurement, but in the hsCRP assay the precision of nephelometry (CV% in the interval 3.0-5.8) was lower than that of turbidimetry (CV% in the interval 1.8-2.3). The classification of results by the two methods into three predefined relative risk classes gave 18% rate of discordance, in any case by one class only. The two methods proved reliable and comparable in the measurement of hsCRP, but precision should be improved.     

超敏CRP检测在肺部感染疾病中的应用分析

目的 探讨超敏C反应蛋白（high sensitive C-reactive protein,Hs-CRP）对肺部感染性疾病病情、预后判断的价值和意义.方法 回顾性分析2009年1月～2009年12月我院呼吸科133名单纯性肺炎患者、68名肺炎合并轻度脓毒症患者和22名肺炎合并重度脓毒血症患者临床资料[1],血清hs-CRP采用乳胶增强免疫比浊法检测[2].结果 单纯肺炎组、合并轻度脓毒症组和合并重度脓毒症组抗生素治疗前超敏CRP分别为36.7±30.8mg/L、88.3±22.8mg/L、144.6±55.8mg/L.治疗一周后三组Hs-CRP水平分别为17.7±11.8mg/L、50.3±13.8mg/L、99.6±25.8mg/L,治疗前三组间数据存在统计学差异（P＜0.05）.与治疗前相比,治疗后三组Hs-CRP水平均存在统计学差异.而治疗前轻度脓毒症组与重度脓毒症组中性粒细胞检测无明显差异（10.7±3.8×10^9/L vs.13.1±6.8×10^9/L,P＞0.05）.抗生素治疗一周后,重度脓毒血症组白细胞（14.8±6.8×10^9/L vs.13.1±6.8×10^9/L）和中性粒细胞计数（13.1±6.8×10^9/L vs.12.1±4.4×10^9/L）较治疗前均无显著差异（P＞0.05）.结论 hs-CRP是反映肺部感染性疾病的严重程度及预后判断有价值的诊断指标.     

Development of a new microparticle-enhanced turbidimetric assay for C-reactive protein with superior features in analytical sensitivity and dynamic range

Novel assay techniques were applied to a newly developed microparticle-based assay for C-reactive protein (CRP). By using two different sized microparticles covalently coated with two monoclonal antibodies of different reactivity, high analytical sensitivity and a high upper measuring limit could be simultaneously attained, resulting in a remarkably wide dynamic range. This range was further increased by calculating the signal (reaction rate) optimally with a new software capability of COBAS® INTEGRA, a clinical chemistry analyzer. The assay showed high precision between 2 mg/l and 160 mg/l with use of only 2.5 μl specimen. The detection limit was estimated as 0.3 mg/l CRP. The assay was four to eight times more sensitive and precise than existing turbidimetric or nephelometric assays with comparable upper measuring limits. The assay also showed good linearity and correlated well with commercial assays. This new microparticle-based CRP assay provides the accuracy and precision that are required to determine CRP at low concentrations where new clinical implications such as prognosis of cardiovascular diseases are envisaged. The assay's wide dynamic range will additionally lead to a reduction in the number of repeated analyses, thus improving the efficiency of CRP determinations in clinical laboratories. J. Clin. Lab. Anal. 12:137–144, 1998. © 1998 Wiley-Liss, Inc.     

Performance characteristics of a point of care C-reactive protein assay.

BACKGROUND: C-reactive protein (CRP) is a non-specific marker of inflammation that can be used for atherosclerotic risk assessment. This application requires increased precision at low CRP concentrations compared to traditional assays. METHODS: The Micros CRP analyzer (ABX Diagnostics) is a small bench top device. Its limit of detection, limit of quantitation, linearity and imprecision were assessed. Method comparison studies were performed using samples both inside and outside the reference interval. Anticoagulant effects and the prozone effect were also evaluated. RESULTS: The limit of detection was 0.1 mg/l. The method was linear from 2 to 60 and 0.3 to 60 mg/l using systematic error limits of 10% and 20%, respectively. The total imprecision was <8% for CRP concentrations from 0.7 to 9.1 mg/l. A prozone effect was seen at CRP concentrations >500 mg/l. Using samples from 120 apparently healthy adults, the Micros CRP method demonstrated excellent concordance with the BN II high sensitivity CRP (hs-CRP) method. The Micros CRP method compared well with a nephelometric method using samples with elevated CRP concentrations. CONCLUSIONS: The Micros CRP method is adequate for atherosclerotic risk prediction in clinical practice but does not have adequate accuracy at CRP concentrations <2 mg/l for epidemiological studies.     

Evaluation of nine automated high-sensitivity C-reactive protein methods: implications for clinical and epidemiological applications. Part 2

BACKGROUND: C-Reactive protein (CRP) can provide prognostic information about risk of future coronary events in apparently healthy subjects. This application requires higher sensitivity assays than have traditionally been available in the clinical laboratory. METHODS: Nine high-sensitivity CRP (hs-CRP) methods from Dade Behring, Daiichi, Denka Seiken, Diagnostic Products Corporation, Iatron, Kamiya, Olympus, Roche, and Wako were evaluated for limit of detection, linearity, precision, prozone effect, and comparability with samples from 388 apparently healthy individuals. RESULTS: All methods had limits of detection that were lower than the manufacturers' claimed limit of quantification except for the Kamiya, Roche, and Wako methods. All methods were linear at 0.3-10 mg/L. The Diagnostic Products Corporation, Kamiya, Olympus, and Wako methods had imprecision (CVs) >10% at 0.15 mg/L. The Iatron, Olympus, and Wako methods demonstrated prozone effects at hs-CRP concentrations of 12, 206, and 117 mg/L, respectively. hs-CRP concentrations demarcating each quartile in a healthy population were method-dependent. Ninety-two to 95% of subjects were classified into the same quartile of hs-CRP established by the Dade Behring method by the Denka Seiken, Diagnostic Products Corporation, Iatron, and Wako methods. In contrast, 68-77% of subjects were classified into the same quartile by the Daiichi, Kamiya, Olympus, and Roche methods. No subject varied by more than one quartile by any method. CONCLUSIONS: Four of the nine examined hs-CRP methods classified apparently healthy subjects into quartiles of hs-CRP similar to the classifications assigned by the comparison method. Additional standardization efforts are required because an individual patient's results will be interpreted using population-based cutpoints.     

Evaluation of Denka-Seiken turbidimetric high-sensitivity C-reactive protein assay.

C-reactive protein measured with a high sensitivity method (hsCRP) is an important prognostic indicator in patients with an acute coronary syndrome. We evaluated hsCRP measurement with regard to its precision, functional sensitivity, linearity, and interferences using Denka-Seiken CRP II Latex X2 turbidimetric method on two chemistry autoanalyzers: Olympus AU 640 and Hitachi 747. The coefficients of variation (CV) for within-run and between-run precision of hsCRP were satisfactory on both autoanalyzers. Functional sensitivities, expressed as concentrations associated with 10% total interassay CV, were 0.19 mg/l for the Hitachi 747 analyzer and 0.41 mg/l for the Olympus AU 640. The assay was linear up to 300 mg/l with a wide measuring range, which suggested the possibility of using this hsCRP measurement as an inflammation marker and as a risk marker for coronary heart disease (CHD). No significant interference was observed up to a triglyceride concentration of 34 mmol/l, and up to hemoglobin concentration of 4 g/l. The determination of hsCRP by turbidimetric method was satisfactory and acceptable for CHD risk assessment, as well as for use as a marker of inflammation.     

Prognostic role of high-sensitivity C-reactive protein and B-type natriuretic peptide in implantable cardioverter-defibrillator patients

Background: High‐sensitivity C‐reactive protein (hs‐CRP) and B‐type natriuretic peptide (BNP) are useful biomarkers for cardiovascular risk stratification. Little data are available regarding the prognostic value of hs‐CRP and BNP serum levels and future ventricular arrhythmic events triggering implantable cardioverter defibrillator (ICD) therapy. Methods: A total of 100 patients eligible for ICD implantation were enrolled in a prospective cohort study. Serum levels of hs‐CRP and BNP were obtained the day before ICD implantation and at scheduled follow‐up visits. For risk analysis, the study cohort was dichotomized based on serum level of hs‐CRP using a cut‐off value of 3 mg/L. The endpoint was appropriate ICD therapy triggered by ventricular arrhythmias during a follow‐up of 24 months. Results: Appropriate ICD therapy was delivered in 20% of patients. Median baseline serum level of hs‐CRP was significantly higher in patients with appropriate ICD therapy than in those without appropriate ICD therapy (5.33 mg/L vs 2.19 mg/L; P = 0.002). The same was true for median serum levels of hs‐CRP and BNP during follow‐up (5.43 mg/L vs 2.61 mg/L, P = 0.001 and 261.0 pg/mL vs 80.1 pg/mL, P = 0.01, respectively). Multivariate analysis demonstrated that baseline hs‐CRP level > 3 mg/L was independently associated with appropriate ICD therapy (odds ratio 4.0, 95% 1.1–14.2; P = 0.03). Conclusion: Elevated preimplantation hs‐CRP serum level is independently associated with increased risk for appropriate ICD therapy. Monitoring for elevated BNP levels during follow‐up adds to the assessment of risk for future arrhythmias. (PACE 2011;1–8)     

Performance characteristics of an automated high-sensitivity C-reactive protein assay on the Dimension RXL analyzer

BACKGROUND: C-reactive protein (CRP) is a nonspecific marker of inflammation that can be used as a marker for atherosclerotic risk. This application requires increased precision at low CRP concentrations compared to traditional assays. METHODS: The Dimension RXL is an automated chemistry analyzer for central laboratory use. The limit of detection, limit of quantification, linearity and imprecision of a high-sensitivity CRP assay developed for it were assessed. Method comparison studies were performed using samples both inside and outside the reference interval. The presence of a prozone effect was also evaluated. RESULTS: The limit of detection was 0.7 mg/l. The method was linear from 2 to 60 mg/l and from 1 to 60 mg/l using systematic error limits of 10% and 20%, respectively. The total imprecision was <10% for CRP concentrations above 1.5 mg/l. No prozone effect was seen at a CRP concentration of 450 mg/l, the highest concentration tested. Using samples from 212 apparently healthy adults, the Dimension RXL method demonstrated good concordance with the BN II high-sensitivity CRP method for samples in the highest quartile. It also compared well using samples with elevated CRP concentrations. CONCLUSIONS: The Dimension RXL high-sensitivity CRP method may be adequate for atherosclerotic risk prediction in clinical practice if accurate and precise measurement is only required for the highest quartile. However, the total error of this method for CRP concentrations <3 mg/l appears too large for accurate assignment to lower risk groups.     

Clinical efficacy of an automated high-sensitivity C-reactive protein assay

BACKGROUND: Prospective studies have shown that C-reactive protein (CRP) can be used to predict risk of future cardiovascular events. High-sensitivity methods for CRP (hs-CRP) measurement are needed for this purpose. METHODS: We compared the clinical efficacy of an automated and commercially available latex-enhanced assay (Latex) for hs-CRP (Dade Behring) to a validated in-house ELISA, previously shown to predict future peripheral arterial disease (PAD) in asymptomatic populations. Using a prospective, nested, case-control design, we measured baseline hs-CRP concentrations in 144 apparently healthy men who subsequently developed symptomatic PAD and 144 age- and smoking habit-matched controls who remained free of vascular disease over the follow-up period of 60 months. RESULTS: The two hs-CRP assays correlated highly (r = 0.95; P <0.001), and all but two participants were classified into concordant quartiles or varied by only one quartile. The median hs-CRP of the case group was significantly higher than that of controls when measured by either the ELISA (1.34 vs 0.99 mg/L; P = 0.034) or the Latex method (1.80 vs 1.20 mg/L; P = 0.042). Furthermore, for both ELISA and the Latex method, the calculated relative risks of developing PAD increased significantly with each increasing quartile of hs-CRP. The calculated interquartile increase in relative risk of PAD was 31% (95% confidence interval, 5.2-62.2%; P = 0.01) for ELISA and 34% (95% confidence interval, 8.2-66.1%; P = 0.007) for the Latex method. CONCLUSIONS: Our findings indicate that the Latex method is equally as efficacious as the validated ELISA in classifying patients into cutoff points established by prospective studies for risk stratification for coronary and cerebrovascular disease.     

High C‐reactive protein levels are associated with oral hormonal menopausal therapy but not with intrauterine levonorgestrel and transdermal estradiol

Objective. Oral hormone replacement therapy (HRT) has been linked to increased cardiovascular (CVD) morbidity. HRT causes a sustained increase in C‐reactive protein (CRP), an excellent marker of subclinical inflammation and CVD. The aim of the study was to support our hypothesis that CRP, which is synthesized in the liver, is not increased in association with transdermal/intrauterine HRT. Material and methods. A case‐control study was performed in which CRP measurements in women receiving levonorgestrel intrauterine system combined with transdermal estradiol (LNG/TDE, n = 27) were followed for 9 months or longer. CRP concentrations in these women were compared with those of either oral HRT users (n = 20) or controls (n = 19). Results. No significant differences were found in CRP concentrations between the LGN/TDE and control groups (1.8±1.2 and 1.8±1.8?mg/L, respectively). However, CRP was significantly increased in the oral HRT group (5.5±2.9?mg/L, p<0.001). Conclusions. CRP is significantly increased by oral HRT but not by the LNG/TDE combination after 9 months of treatment. This trend may explain the preponderance of some menopausal women on HRT being at increased risk for the development of CVD. Therefore, the use of LNG/TDE is acceptable for relief of severe climacteric symptoms possibly not imposing an increased CVD risk documented upon oral HRT.     

血清降钙素原鉴别细菌性感染的临床价值

目的比较血清降钙素原(PCT)水平与其他炎症指标对鉴别诊断细菌性感染的临床价值。方法采用回顾性队列研究,按临床病例终诊结果将患者分为细菌性感染和非细菌性感染两组,采用受试者工作特征曲线比较PCT、C反应蛋白(CRP)、白细胞计数(WBC)3项炎症指标对细菌性感染的诊断价值。结果预测细菌性感染的ROC曲线下面积PCT为0.89,CRP为0.70,WBC为0.60;以PCT>0.25 ng/mL为阳性界值诊断细菌性感染的灵敏度为46%,特异度为100%;以PCT≥0.1 ng/mL为临界值则灵敏度达75%,特异度96%;CRP>5 mg/L的诊断灵敏度为85%,特异度为38%;WBC>10.0×109/L的诊断灵敏度为39%,特异度为82%。结论在鉴别细菌性感染和其他炎症疾病上,血清PCT优于CRP和WBC,以PCT≥0.1 ng/mL为阳性界值,对诊断有最佳的灵敏度和特异度。