[SFBC Working Group on sources of errors in laboratory medicine: objectives and key areas of work].

Laboratory medicine plays a crucial role in patient care, contributing to approximately 70 % of clinical decisions. In collaboration with clinicians, laboratory medicine specialists perform analyses that are useful for diagnosis, screening and prevention. Laboratories are known for their efficiency, which is reached through a rigorous quality system.

Preanalytical, analytical and postanalytical considerations in circulating microRNAs measurement.

Microribonucleic acids (miRNAs) have emerged as a new category of biomarkers for many human diseases like cancer, cardiovascular and neurodegenerative disorders. MicroRNAs can be detected in various body fluids including blood, urine and cerebrospinal fluid. However, the literature contains conflicting results for circulating miRNAs, which is the main barrier to using miRNAs as non-invasive biomarkers.

[Measurement of angiotensin-I-converting enzyme in the blood: help for method validation].

Blood angiotensin-converting enzyme (ACE) assay is now realized by the determination of enzyme activity on synthetic substrate, mostly furylacryloyl-phenylalanyl-L-glycyl-L-glycine (FAPGG). The matrix can be serum or heparin-plasma, with or without a separator; the assay developed on serum or plasma is not adapted to other matrix such as cerebrospinal fluid where the ACE activity is much lower. This assay has been adapted on a number of automated biochemistry analyzers with the specifications of the supplier of reagents, sometimes with modification of volumes or times for analysis.

Glycated albumin.

Glycated hemoglobin (HbA) is the reference test for long-term glucose monitoring. However, HbA is not recommended in several situations such as hemoglobinopathies, pregnancy or chronic kidney disease. The quantification of serum glycated albumin (GA) can serve as an alternative in these situations.

Circulating microRNAs as novel biomarkers of Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disorder. Biomarkers could help identify patients at risk and define stages of this disease. Furthermore, biomarkers can be used to evaluate the efficiency of therapeutic agents under testing and thus accelerate the therapeutic discovery process.

[The microRNAs as biomarkers: What prospects?].

MicroRNAs are nucleic acids of about twenty nucleotides that regulate about a third of the genome at the post-transcriptional level. Thanks to their different forms of transport, microRNAs are stable and can be detected in biological fluids such as blood, urine, cerebrospinal fluid, or saliva. In addition, the profile of circulating microRNAs is a specific part of the cells in which it is secreted and is modified according to the physiological or pathological conditions of these cells.

Role of mass spectrometry in steroid assays.

In addition to protein hormones, steroids measurement constitutes the basis of modern endocrinology. Immunoassays have shown their limits in this field. In contrast, mass spectrometry shows an excellent sensitivity and specificity that make it the method of choice for steroids assays.