[Evaluation of an automated assay of thyrotropin receptor antibody (TRAb) on Elecsys Analyser 2010]. / Evaluation du dosage automatisé des auto-anticorps anti-récepteur de la TSH sur l'analyseur Elecsys 2010.

2nd generation assays are currently available to determine the concentration of thyrotropin receptor antibody (TRAb) present in Graves' disease. The aim of this study was to evaluate the analytical performance of TRAb assay on Elecsys 2010 and Cobas(R)e of Roche Diagnostics, a new test using electrochemiluminescence immunoassay (ECLIA). The analytical performance observed with this assay is accurate (repetability and reproductibility, analytical and functional sensitivities). Comparing this method with Brahms' assay (TRAK human RIA), the correlation observed can be put in the equation: y = 1.013 x + 1.381; r = 0.92. With a positive value in ECLIA at 0.9 UI/L and at 1 UI/L in RIA (functional sensitivity fixed by manufacturers), concordance study shows a false negative and two false positive. With a positive value at 0.8 UI/L with ECLIA (functional sensitivity calculated from precision's profile for a CV inferior to 10%), there is no false negative and two false-positive results, this value seems to give a better sensitivity.

[NT-proBNP in practice: from chemistry to medicine]. / NT-proBNP en pratique "de la biologie à la clinique".

Since introduction of routine assay for natriuretic peptides, there are a growing number of clinical applications for those new tests. Numerous studies have defined analytical characteristics and clinical interest of NT-proBNP assay. Originally limited to acute heart failure diagnosis in the emergency room, NT-proBNP assay has now a wide number of applications. This review presents the "state of art" of this marker, detailing NT-proBNP physiological recent knowledge and its recognized or investigated clinical applications.

[Interest of S100B protein blood level determination for the management of patients with minor head trauma]. / Intérêt du dosage sérique de la protéine S100B dans la prise en charge du patient après traumatisme crânien léger.

Indication of cranial computed tomography (CCT) for patients with head minor injury (MHI) is difficult. Actually, 90% of patients with MHI who have CCT under the present clinical decision rules have normal scans. Serum concentrations of the protein S-100B were recently found to provide useful information. We have investigated whether S-100B concentrations in patients with MHI can provide additional information to improve indication of the need for an initial CCT scan. One hundred five patients with MHI were enrolled in this prospective study, at the French university hospital of Marseille and Clermont-Ferrand. Of the 105 patients studied, 16 exhibited trauma-relevant intracerebral lesions on the CCT scan (CCT+). With a cut-off limit of 0,10 microg/L S-100B, CCT+ patients were identified with a sensitivity level of 100% and a specificity level of 33%. Adding the measurement of S-100B serum concentration to the clinical decision rules for a CCT scan in patients with MHI could allow a 30% reduction in scans.

[Estimation of the glomerular filtration rate in elderly inpatients: comparison of four methods]. / Quelle méthode d'évaluation de la fonction rénale utiliser chez le sujet âgé hospitalisé en unité de court séjour gériatrique ? Comparaison de quatre méthodes.

PURPOSE: High variability has been observed in the estimation of the glomerular filtration rate (GFR) in older patients, according to the formula used and no single formula has been recommended to date. The aim of this study was to quantify the precision and accuracy of the GFR estimated by means of three formulas and the measurement of cystatin C. METHODS: This prospective study was conducted in an acute care geriatric unit. Participants were patients, aged 70 years and over, having a possible 24-hour urine collection. The GFR was estimated using the Cockroft-Gault (CG), the Modification of Diet in Renal Disease (MDRD), and the Creatinine Clearance (Cl-Cr) formulas. The serum level of cystatin C was also measured. RESULTS: Eighty-one patients were included in the study. CG formula underestimated the GFR by a mean difference of 8.65 ml/min, compared with MDRD formula. Cl-Cr underestimated the GFR by a mean difference of 7.56 ml/min, compared with CG formula, and by a mean difference of 16.79 ml/min, compared with the MDRD formula. The degree of discrepancy between CG and Cl-Cr estimates, and between Cl-Cr and MDRD estimates decreased as the estimated GFR approached normal values. MDRD best matched the measurement of cystatin C, followed by CG and Cl-Cr (Kappa coefficient=0.43, 0.22 and 0.16, respectively). CONCLUSION: Our study confirms the high variability of GFR in older patients and particularly in those with abnormal renal function, depending on the formula used. Serum cystatine C level and MDRD formula appear to be the most concordant estimates of GFR in this population.

Cystatin C is not more sensitive than creatinine for detecting early renal impairment in patients with diabetes.

This study evaluated serum cystatin C as a potential new marker of glomerular filtration rate (GFR) in 49 patients who had steady-state diabetes with early renal impairment. We determined the correlation between GFR measured by chromium 51-labeled EDTA and levels of serum cystatin C, serum creatinine, serum beta(2)-microglobulin, endogenous creatinine clearance, and Cockcroft formula. Sensitivity and specificity for the diagnosis of renal failure, defined as a GFR less than either 80 or 60 mL/min/1.73 m(2), were calculated by receiver operating characteristic (ROC) curves for creatinine, cystatin C, and beta(2)-microglobulin. Finally, we compared mean values of these three serum parameters in patients grouped according to GFR using the two definitions of renal failure. Correlation coefficients with GFR were -0.77 for serum creatinine level, -0.65 for serum cystatin C level, -0.71 for serum beta(2)-microglobulin level, +0.56 for endogenous creatinine clearance, and +0.69 for Cockcroft formula (all P < 0.001). With a cutoff value of 60 mL/min/1.73 m(2), areas under the ROC curve were 0.972 for beta(2)-microglobulin, 0.925 for cystatin C, and 0.916 for creatinine levels. With a cutoff value of 80 mL/min/1.73 m(2), these were 0.838 for beta(2)-microglobulin, 0.780 for cystatin C, and 0.905 for creatinine levels (P = not significant between parameters). These results were not altered after the exclusion of patients (n = 8) with a serum creatinine level greater than 1.41 mg/dL. When patients were classified into three groups according to GFR (group 1, >80 mL/min/1.73 m(2); group 2, 60 to 80 mL/min/1.73 m(2); group 3, <60 mL/min/1.73 m(2)), mean values of serum parameters in the three groups were statistically different (P < 0.0001) except between groups 1 and 2 for cystatin C and beta(2)-microglobulin. With patients classified into two groups (GFR > or < 80 mL/min/1.73 m(2)), mean values for each parameter were statistically different (P < 0.001). Sensitivity, specificity, and positive and negative predictive values for serum creatinine and serum cystatin C levels were very close for both definitions of renal failure. Serum cystatin C is not better than serum creatinine or serum beta(2)-microglobulin levels for estimating GFR in patients with steady-state diabetes using ROC curves or other validation tests.

Increased plasma levels of pro-brain natriuretic peptide in patients with cardiovascular complications following off-pump coronary artery surgery.

OBJECTIVE: To compare N-terminal pro-brain natriuretic peptide (NT-pro-BNP), procalcitonin (PCT), and troponin I (Tn I) concentrations during and after coronary artery surgery in patients with or without cardiovascular complications. DESIGN AND SETTING: Prospective, comparative study of 12 months in the cardiovascular intensive care unit in a university hospital. PATIENTS: 60 adult patients undergoing coronary artery bypass grafting with the off-pump technique. MEASUREMENTS AND RESULTS: Plasma NT-pro-BNP, PCT, and Tn I levels were measured before and immediately after the end of operation and on PODs 1, and 2 and 3. We defined complicated postoperative course as myocardial infarction, cardiogenic shock, arrhythmias, congestive heart failure, and death occurring after the fourth postoperative hour. Receiver operating characteristic (ROC) curve cutoff values were used to assess the ability of the three markers to predict future cardiac events. The area under ROC curve (AUC) using NT-pro-BNP to detect a cardiovascular complicated course was 0.780 at the preoperative time and 0.850 at the end of surgery. A preoperative NT-pro-BNP value of 397 pg/ml had a sensitivity of 76%, specificity of 67%, and accuracy of 74% for predicting a subsequent cardiovascular complication. An immediate postoperative NT-pro-BNP value of 430 pg/ml had a sensitivity of 80%, specificity of 77%, and accuracy of 76%. Patients with preoperative NT-pro-BNP levels less than 275 pg/ml had an excellent postoperative prognosis. Other two markers were less appropriate. CONCLUSIONS: NT-pro-BNP levels measured before and immediately after off-pump coronary artery bypass seem to be predictive of postoperative cardiac events.

Association of APOE promoter but not A2M polymorphisms with risk of developing Alzheimer's disease.

The APOE4 allele is widely accepted as a major risk factor for late-onset Alzheimer's disease (AD). Recently, it has been reported that polymorphisms in the APOE promoter and in the alpha2-macroglobulin gene (A2M) are associated with AD. We have analyzed the distribution of APOE alleles, -219T/G APOE promoter polymorphism, and A2M/A2Mdel polymorphism in a large case-control study. Our results showed that APOE genotype was the only informative marker of AD risk contrary to -219T/G and A2M/A2Mdel polymorphism. In AD patients however, a strong linkage disequilibrium was observed between the T allele of -219T/G polymorphism and APOE4 allele. This result indicates that -219T/G APOE promoter polymorphism is a risk factor for AD by increasing the APOE4-associated risk.

[Ursodeoxycholic acid and prevention of tacrine-induced hepatotoxicity: a pilot study]. / Acide ursodésoxycholique et prévention de l'hépatotoxicité de la tacrine: une étude pilote.

Ursodeoxycholic acid is a protective agent against liver toxicity caused by some drugs. In the present pilot study, we assessed the effect of this bile acid on tacrine-induced hepatotoxicity. Fourteen patients with a diagnosis of Alzheimer's disease received tacrine and ursodeoxycholic acid (13 mg/kg/day) for 105 days. Serum ALAT was the main evaluation criterion. Serum levels of ALAT were compared with those of 100 patients who had been treated with tacrine in the same centre. In patients receiving ursodeoxycholic acid, ALAT serum levels were normal in 93 per cent of cases vs. 69 per cent in control patients and moderate hepatotoxicity (ULN < ALAT < 3 ULN) did not occur while it was present in 25 per cent of controls (p = 0.036). In contrast, the percentage of patients with ALAT > 3 ULN was similar in the two groups (7 per cent vs. 6 per cent). These present findings suggest that UDC could prevent moderate tacrine-induced hepatotoxicity. These results should be confirmed in a controlled therapeutical trial.

[Reaction surveillance: organization in public care/hospitals in Marseille]. / Réactovigilance: quelle organisation à l'Assistance publique-Hôpitaux de Marseille ?

For the French Drug Agency (AFSSAPS), the aim of the reactovigilance is to monitor the adverse effects resulting from the use of IVD-MD. More precisely, the goal is to evaluate all incidents and risks that can result in inadequate results or negative effects to the user and therefore for the patient. According to the French Law and before the transposition in the French Law of the European Guideline 98/79/CE, the University Hospital of Marseille has decided to organize its own reactovigilance network. Since 2001, an institutional organization has been set up. For each of the 33 labs of the University hospital one reactovigilant has been nominated as well as one coordinating reactovigilant. Specialized structures have been created: one central committee and one experts group. Standardized operating procedures have been established. The reactovigilance system is also integrated to the vigilance coordination network of the Marseille University Hospital. This organization allows to achieve tracability of all alerts, as well as information and training for the professionals. Four missions are defined: collection and management of all incidents IVD-MD-related; diffusion of AFFSAPS and industrials alerts to all labs in order to take appropriate measures; Tracability of alerts and incidents in all labs and in central committee, tracability of reactives according to French guidelines (GBEA). For the first 10 months of 2002, 46 alerts have been forwarded to all lab's correspondants. In the same period, one real adverse event has been locally notified and after analyse will be forwarded to the AFSSAPS. All these factors should contribute to the health professionals interest and participation in reactovigilance activities.

[Incidence of myocardial lesions after vascular surgery: diagnosis by troponin Ic]. / Incidence des lésions myocardiques après chirurgie vasculaire: diagnostic par la troponine Ic.

OBJECTIVE: To compare the incidence of myocardial damages diagnosed following vascular surgery using the cardiac troponin I measurement technique and conventional methods. STUDY DESIGN: Prospective epidemiological study. PATIENTS: Fifty-four patients who underwent surgery for either aneurysmal disease in 28 cases or occlusive aortic disease in 26 cases. METHODS: Plasma concentration of cardiac troponin I (significant at a concentration > 1.5 ng.mL-1) was measured by immunoenzymofluorimetry on the second and fifth postoperative days. Conventional monitoring methods included daily electrocardiogram (ECG), enzymatic assay of total-PCK, and measurement of plasma levels of the MB isoenzyme of phosphokinase creatine (MB-PCK) (significant at > 1 ng.mL-1 and RI > 1.5). RESULTS: The cardiac troponin I measurement technique allowed the diagnosis of minor myocardial damages during the postoperative period in five patients, whereas with the conventional methods (clinical signs. ECG, and MB-PCK) only three myocardial lesions were diagnosed. CONCLUSION: The cardiac troponin I measurement technique allows diagnosis of minor myocardial damages following vascular surgery. Conventional methods underestimate the incidence of these damages.

[Guidelines for point-of-care testing quality management according to ISO 22870]. / Recommandations pour la mise en place d'un système de management de la qualité des examens de biologie médicale délocalisés.

In this paper, we focus on the additional requirements of EN ISO 22870 compared to those described in Chapter 4: Quality Management of EN ISO 15189. They concern the quality policy, the management reviews and the audits. Thus, we propose a template of quality policy statement, and specific requirements for conducting management review of POCT are given. Finally, a questionnaire for performing an audit of POCT activities is proposed. The composition and activities of the multidisciplinary group for the supervision of POCT activities, which is also a specific requirement of EN ISO 22870, is discussed in another article of this volume.

[NT-proBNP in practice: from chemistry to medicine]. / NT-proBNP en pratique "De la biologie à la clinique".

Since the introduction of routine assay for natriuretic peptides, there are a growing number of clinical applications for those new tests. Numerous studies have defined analytical characteristics and clinical interest of NT-proBNP assay. Originally limited to acute heart failure diagnosis in the emergency room, NT-proBNP assay has now a wide number of applications. This literature review presents the "state of art" of this marker, detailing NT-proBNP physiological recent knowledge and its recognized or investigated clinical applications.

Determination of nicotine and its main metabolites in urine by high-performance liquid chromatography.

Nicotine and its main metabolites (cotinine, trans-3'-hydroxycotinine, trans-3'-hydroxycotinine glucuronide, nicotine-1'-N-oxide and 3-pyridylcarbinol) were analysed in urine after liquid-liquid extraction by high-performance liquid chromatography using norephedrine as internal standard, ultraviolet detection at 260 nm and scanning ultraviolet spectra with a photodiode-array detector. The conjugated trans-3'-hydroxycotinine was determined after enzymatic hydrolysis. Specific determination of 3-pyridylcarbinol was also carried out. Owing to its good selectivity, sensitivity and reproducibility, the method was applied to the analysis of urine samples from smokers and non-smokers. The results obtained suggest that the urinary markers used to assess active smoking or exposure to environmental tobacco smoke must be not only nicotine and cotinine, but also their main free and conjugated metabolites.

Rapid and sensitive high-performance liquid chromatographic determination of nicotine and cotinine in nonsmoker human and rat urines.

A simple reversed-phase high-performance liquid chromatographic method with paired-ion and UV detection has been developed for the rapid quantification of urinary nicotine and cotinine. A one-step solid-liquid extraction on Extrelut was used. Separation from endogenous substances was achieved with a decreasing flow-rate. With 20 ml of urine for extraction, the limit of quantification was 0.5 ng/ml for cotinine and 5 ng/ml for nicotine; linearity was obtained from 50 to 5000 ng/ml. The intra- and inter-day coefficients of variation were less than 9% for cotinine and 30% for nicotine. Average recoveries for cotinine were 92-100% and 47-86% for nicotine. The present method was applied to the urine analysis of smokers, nonsmoker children, and experimental animals.

Possible interaction between exposure to environmental tobacco smoke and therapy in children with asthma.

1. The aim of the study was to determine the carbachol and albuterol responsiveness in treated and untreated asthmatic and allergic children exposed to environmental tobacco smoke assessed by urinary cotinine measurements. 2. Forty-six asthmatic and allergic children with normal spirometric values were recruited. The doubling dose, concentration of carbachol producing a 2-fold increase in specific airway resistance (SRaw) was determined and 200 micrograms of albuterol were administered via a Volumatic(R) spacer. The percentage of bronchodilatation was defined as the difference between the largest obtained SRaw and the post-beta2 SRaw divided by the largest SRaw. Data were compared by a Mann-Whitney U-test. 3. The 23 children with a high urinary cotinine, compared with the 23 children without urinary cotinine, had a decreased doubling dose (108.2+/-14.7 micrograms versus 160.9+/-19.5 micrograms; P=0.04) and an increased percentage of bronchodilatation (74.8+/-1.4% versus 68.8+/-1.8%; P=0.03). A prophylactic anti-inflammatory treatment induced a weaker bronchial reactivity to carbachol and a slightly greater bronchodilatation in children exposed to environmental tobacco smoke. 4. Environmental tobacco smoke increases bronchial reactivity in asthmatic and allergic children. This effect might be reduced by anti-inflammatory therapy. The bronchodilator response may be enhanced in exposed children and may be caused by one or several direct interactions between tobacco smoke compounds and albuterol.

High concentrations of N-BNP are related to non-infectious severe SIRS associated with cardiovascular dysfunction occurring after off-pump coronary artery surgery.

BACKGROUND: Procalcitonin (PCT) blood concentrations are known to be an appropriate marker of severe systemic inflammatory response syndrome (SIRS) induced by coronary artery surgery with and without cardiopulmonary bypass. Pro-brain natriuretic peptide (N-BNP) is a newly described cardiac hormone considered to be an effective marker of severity and prognosis of acute coronary syndromes and congestive heart failure. We evaluated the perioperative time courses of PCT and N-BNP and investigated their role as early markers of severe SIRS (SIRS with cardiovascular dysfunction) induced by off-pump coronary artery bypass (OPCAB). METHODS: Sixty-three patients were prospectively included. The American College of Chest Physicians Classification was used to diagnose SIRS and organ system failure to define severe SIRS. Serum concentrations of PCT and N-BNP were determined before, during and after surgery. Receiver operating characteristic curves and cut-off values were used to assess the ability of these markers to predict postoperative severe SIRS. RESULTS: SIRS occurred in 25 (39%) patients. Nine of them (14%) showed severe SIRS. Significantly higher serum concentrations of N-BNP and PCT were found in patients with severe SIRS with peak concentrations respectively at 8887 pg ml(-1) (range 2940-29372 pg ml(-1)) for N-BNP and 9.50 ng ml(-1) (range 1-65 ng ml(-1)) for PCT. The area under the curve using N-BNP to detect postoperative severe SIRS was 0.799 before surgery (0.408 for PCT; P<0.01) and 0.824 at the end of surgery (0.762 for PCT; P<0.05). CONCLUSIONS: N-BNP may be an appropriate marker indicating the early development of non-infectious postoperative severe SIRS after OPCAB.

Urinary cotinine and exposure to parental smoking in a population of children with asthma.

BACKGROUND: Studies of the effects of tobacco smoke often rely on reported exposure to cigarette smoke, a measure that is subject to bias. We describe here the relationship between parental smoking exposure as assessed by urinary cotinine excretion and lung function in children with asthma. METHODS: We studied 90 children 4-14 years of age, who reported a confirmed diagnosis or symptoms of asthma. In each child, we assessed baseline pulmonary function (spirometry) and bronchial responsiveness to carbachol stimulation. Urinary cotinine was measured by HPLC with ultraviolet detection. RESULTS: Urinary cotinine concentrations in the children were significantly correlated (P <0.001) with the number of cigarettes the parents, especially the mothers, smoked. Bronchial responsiveness to carbachol (but not spirometry test results) was correlated (P <0.03) with urinary cotinine in the children. CONCLUSION: Passive smoke exposure increases the bronchial responsiveness to carbachol in asthmatic children.