[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.

[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.