[Lipemia and bilirubin influences for twenty-four biochemical parameters measurement]. / Interférences de la lipémie et de l'ictère sur le dosage de 24 paramètres biochimiques.

The study of the influence of the lipemia and icterus was performed experimentally for twenty-four biochemistry parameters on the Roche Cobas 6000 CE analyzer. Overloads in Intralipid(®) or ditaurate of bilirubin were performed on several plasma pools. The limit of 10% was chosen to define interference on the measurement. The parameters studied were classified into different categories depending on their measurement is affected or not. Knowledge of these data allows the biologist to adapt its reporting procedures in the case of lactescent and/or icteric samples.

[Comparison of calculated LDL cholesterol (LDL-C) versus measured LDL cholesterol (LDL-M) and potential impact in terms of therapeutic management]. / Évaluation d'une méthode de dosage direct du LDL-cholestérol et de son impact potentiel en termes de prise en charge thérapeutique.

LDL-cholesterol value is one of the criteria used by the Haute autorité de santé (HAS) in the management of patients in primary and secondary prevention with the aim to reduce cardiovascular mortality. In this respect, the recommendations have been established based on target to achieve LDL-cholesterol. Currently in France, the determination of LDL-cholesterol is mainly carried out by the Friedewald formula whose limits are well known. However, reliable methods for the determination of LDL-cholesterol exist. We compared the results of calculated and measured LDL-cholesterol obtained from 444 patients presenting normal triglyceridemia values in terms of ranking relative to the thresholds of the HAS. The correlation between the two methods is quite good, but a significant difference (p <0.0001) was observed between the calculated and measured values of LDL-cholesterol. On the other hand in 17% of cases the classification of subjects will be different, with a majority so overestimation of calculated LDL-cholesterol with respect to measured LDL-cholesterol. This overestimation is not proportional, in fact most values measured LDL-cholesterol, the higher the calculate-measured difference is important. The rating difference is particularly important when subjects have between 1 and 3 factors of cardiovascular risk where the target LDL-cholesterol to achieve is between 1.3 and 1.9 g/L. The management of patients with lipid lowering may potentially be dependent on the method used for the determination of LDL-cholesterol.

[Hemolysis influence on twenty-two biochemical parameters measurement]. / Interférence de l'hémolyse sur le dosage de vingt-deux paramètres biochimiques.

The study of the influence of hemolysis was determined experimentally for twenty two biochemical parameters on the analyzer Cobas 6000 ce (Roche Diagnostics). The addition method of hemolysate was used to create an increasing concentration of hemoglobin ranging from 0 to 2000 µmol/L. The limit of 10% variation was chosen to define the influence of hemolysis on the measurement. The parameters studied were classified into several categories: the parameters for which hemolysis does not influence the measurement: albumin, uric acid, calcium, C-reactive protein, myoglobin, NT -pro BNP, S100 protein, and urea; parameters impacted positively leading to an overestimation of the result: aspartate aminotransferase, total cholesterol, creatine kinase, creatinine, lactate dehydrogenase, magnesium, magnesium, total protein, triglycerides; and negatively impacted settings so causing an underestimation of the result: alanine amino- transferase, gamma glutamyl transferase, lipase, alkaline phosphatase, troponin T hypersensitive. Certain parameters influence of hemolysis varies depending on the magnitude of the measured parameter this interference being observed for normal values but disappearing for pathological values: creatinine, cholesterol, alkaline phosphatase, triglycerides, or the inverse interference is greater than for conventional pathological values: lipase, alanine amino-transferase. Knowledge of this variability interference allows the biologist to adapt its methods of reporting in the case of haemolysed samples.

[Influence of anticoagulant on the plasma level of fifteen biochemical parameters]. / Influence de la nature de l'anticoagulant sur le dosage plasmatique de quinze paramètres biochimiques.

The study of the influence of the anticoagulant used in blood collection tubes to obtain plasma was performed for fifteen biochemical parameters measured with automated Cobas 6000 (Roche Diagnostics). For each parameter tested the entire measurement domain was studied. The comparison of results obtained on plasma blood sample obtained by lithium heparin and EDTA include: correlation, the limits of acceptability in the standards of monitoring and interpretation standards regression defined by the SFBC and analysis of Bland-Altman. The parameters studied were classified into three categories. The parameters for which the assay is not influenced by the nature of the anticoagulant used: apolipoprotéin A1, apolipoprotein B, alanine amino-transferase, creatine kinase, creatinine, total cholesterol, HDL-cholesterol, lipase, NT-Pro BNP, troponine T and urea. The parameters for which the results are underestimated EDTA plasma, including those for which the impact is moderate and for which the interpretive standards are not changed: triglycerides, and those for which performance standards are changed on one or more levels: aspartate aminotransferase and lactate dehydrogenase; and finally the not practicable EDTA plasma parameters: alkaline phosphatase.

Value of neuropsychological testing, imaging, and CSF biomarkers for the differential diagnosis and prognosis of clinically ambiguous dementia.

The objective of this study was to examine the diagnostic accuracy of imaging and CSF biomarkers in clinically ambiguous dementia (CAD). 69 patients were prospectively followed. The endpoint was clinical diagnosis at follow-up of 24 months based upon existing criteria. Medial temporal lobe atrophy score on MRI, distinctive patterns on 99 mTc-HMPAO-SPECT, and CSF levels of amyloid-ß peptide, total tau protein, and P-tau181P were used together with neuropsychological testing to assess Se (sensitivity) and Sp (specificity) of separate and combined markers. 60 patients reached the endpoint. A definite diagnosis was achieved in 48 patients. CSF biomarkers had a Sp of 71% and a Se of 100% for Alzheimer's disease (AD) diagnosis. Sp increased to 88% and 93% when MRI and MRI + SPECT were combined, at the expense of Se. CSF biomarkers levels also provided clues to frontotemporal (FTD) or vascular dementias (VaD) diagnosis when situated in an intermediate range between normal and pathological values. MRI and SPECT contributed mostly to the diagnosis of VaD (Se 88%, Sp 75%) and FTD (Se 73%, Sp 78%), respectively. Initial neuropsychological testing had a poor diagnostic accuracy, except for a neuropsychiatric inventory score >40 for the diagnosis of FTD (Se 73%, Sp 84%). Independent of the clinical diagnosis, medial temporal lobe atrophy and total-tau were best correlated with cognitive decline at 2 years. In conclusion, CSF biomarkers efficiently predict evolution toward an AD phenotype in CAD. Imaging biomarkers mostly contribute to the differential diagnosis between non-AD dementias. Initial neuropsychological testing was poorly contributive in CAD diagnosis.

Ischemia-modified albumin and heart fatty acid-binding protein: could early ischemic cardiac biomarkers be used in acute stroke management?

BACKGROUND: The detection of biomarkers such as ischemia-modified albumin (IMA) and heart fatty acid-binding protein (HFABP) is used in the early diagnosis of acute myocardial infarction. As these biomarkers are not organ specific, we tested them in the neurovascular field. METHODS: A total of 41 patients with acute stroke were enrolled (31 ischemic strokes and 10 intracerebral hemorrhages). IMA and HFABP levels were measured in serum samples collected within 4.5 hours of stroke onset. Clinical, imaging, and outcome data were recorded. RESULTS: No difference in baseline IMA or HFABP was found between patients with ischemic and hemorrhagic stroke. There was no correlation among biomarker levels at admission, National Institutes of Health Stroke Scale score, or stroke volume. Neither of the biomarkers could predict short-term prognosis. CONCLUSIONS: IMA and HFABP do not appear to be relevant in acute stroke management.

Prospective clinical and biological comparison of three blood cardioplegia techniques in low-risk CABG patients: better is worse than good enough.

OBJECTIVE: Three myocardial protection techniques were evaluated in a prospective, randomised trial during coronary artery bypass grafts in 69 patients. MATERIAL AND METHOD: Twenty seven patients received intermittent hyperkalaemic undiluted warm blood anterograde cardioplegia (AC), 21 received continuous hyperkalaemic undiluted warm blood retrograde cardioplegia (RC) and 21 received intermittent, hyperkalaemic, diluted cold blood (15 degrees C), anterograde cardioplegia (CC). Assessment criteria were clinical, laboratory and haemodynamic. RESULTS: Groups were homogeneous in terms of age, sex, cardiovascular risk factors, severity of coronary disease, preoperative ejection fraction, and number of bypass grafts performed. The oxygen extraction coefficient, and lactate and troponin production in the coronary sinus on aortic unclamping was not significantly different between the three groups. The base excess was -0.19+/-0.13 in the RC group, -0.18+/-0.52 in the AC group and -2.67+/-0.59 in the CC group (P<0.01 CC vs. AC and CC vs. RC). The priming volume was 1485+/-64 ml (CC), 1317+/-44 ml (RC) and 1318+/-30 ml (AC) (P<0.05 CC vs. AC and CC vs. RC). The haematocrit during CPB was 28.9+/-0.9 (CC), 32.5+/-0.8 (RC) and 32+/-0.7 (AC) (P<0.05 CC vs. AC and CC vs. RC). The volume of crystalloid delivered was 735+/-85 ml (CC), 362+/-67 ml (RC) and 357+/-105 ml (AC) (P<0.05 CC vs. AC and CC vs. RC). The incidence of ventricular fibrillation on aortic unclamping was 61.9% (CC), 9.5% (RC) and 0% (AC) (P<0.01 CC vs. AC and CC vs. RC). The transfusion rate, duration of intubation, postoperative troponin level, complication rate and mortality were not significantly different between the three groups. Haemodynamic parameters at H2, H4, H8 did not vary significantly between the three groups. CONCLUSION: These three techniques appear to be comparable in terms of myocardial protection. Anterograde cardioplegia ensures an identical degree of security to retrograde cardioplegia regardless of the coronary lesions, apart from redo lesions. CC requires greater haemodilution of the patients during CPB.