[Evaluation of two automated methods for blood lactate levels]. / Evaluation de deux méthodes de dosage de la concentration sanguine de lactate.

We evaluated two automated methods for measuring blood levels of lactates with Integra 800 (Roche Diagnostics) and ABL 725 (Radiometer). Our evaluation had shown a within run imprecision of 1% (Intégra 800) and 2% (ABL 725) and a between-assay imprecision of 2% (Intégra 800) and 5% (ABL 725). The two methodologies appeared very well associated. The selective electrode remains expensive but it is very interesting because it saves a blood sample.

[Analytical interference in determination of procalcitonin by PCT-Q (Brahms)]. / Interférence analytique dans le dosage semi-quantitatif de la procalcitonine (PCT-Q Brahms).

Procalcitonin (PCT) is a biological marker of infection. We present the cas of a patient who has presented a high concentration of PCT with PCT-Q test (Brahms). At the same time, the concentration of CRP is remained low, which is no physiological. Then, PCT concentration has been determinated with an automatic system (Kryptor-Brahms) and finded at low than 0.5 microg/l. Brahms company has searched an analytical interference: human anti-mouse antibodies (HAMA) were positive. If PCT concentration stay a marker of infection for the most part, this case show that biologists have to keep in mind that immunological assays remain submitted to interferences.

[Acute organophosphorus pesticide poisoning and cholinesterases activities]. / Intoxication aiguë au pesticide organophosphoré et activités des cholinestérases.

Suicides attempts with an organophosphate pesticide still occur in Brittany, an agricultural French area. The acute poisoning due to this nerve agent, responsible for the inhibition of the cholinesterases enzymes, is severe and can be fatal. The diagnosis is based on the decrease of cholinesterases activity, an assay which has been performed because of the patient context. The measurement of butyrylcholinesterases activity in emergency guarantees an appropriate and rapid management of the patient in order to rapidly regenerate cholinesterases. Even if the decrease level of butyrylcholinesterases activity does not give a significant prognostic value, its follow-up with time indicates the efficacy of the treatment and the gradual remission. In routine the measurement of acetylcholinesterase activity is more useful for the biological follow-up of subjects exposed to organophosphate phytosanitary compounds.

[Evaluation of an automated method for measuring low-density lipoprotein cholesterol]. / Evaluation du dosage direct du cholestérol des lipoprotéines LDL.

We evaluated an automated method for measuring low-density lipoprotein cholesterol (LDL-cholesterol) with Integra 800 (Roche Diagnostics). This method uses detergents which show selectivity for the different lipoproteins. Our evaluation has shown a within run imprecision of 2% and a between-assay imprecision of 1.2%. This method was not perturbed by haemoglobin, bilirubin or lipids. However, the reagents remain expensive: we will use it when calculation or interpretation of lipid results are not possible.