[Production of monoclonal antibodies]. / Production des anticorps monoclonaux.

In contrast to a polyclonal antiserum, a monoclonal antibody is specific to a single epitope on the surface of a complex antigen. In 1975, Kohler and Milstein produced the first monoclonal antibodies by using a method which rapidly became a key technology in immunology. By fusing activated antibody-forming cells (B cells) with myeloma cells, they obtained hybrid cells--the so-called hydridomas--which combine the ability of the activated B cells to secrete a single species of antibody and the immortality of the myeloma cell. The selected hybridomas proliferate continuously, their clonal progeny providing an unending supply of antibody with a single specificity. These antibodies have found many applications in basic research and in vitro diagnosis. In the clinical laboratory, monoclonal antibodies are used as reagents in immunoassays, often replacing traditional antisera. Many years of development and innovation were needed to humanize monoclonal antibodies in order to make them usable in human therapy.

[Interest of monoclonal antibodies in biomedical laboratory analysis]. / Intérêt des anticorps monoclonaux dans le laboratoire d'analyses biomédicales.

Immunoassays, or assays with antibodies as reagents, are widely used in medical laboratories. These assays are used to identify and quantify various substances in biological fluids, such as specific proteins (various tissue markers, markers of inflammation, hormones, coagulation factors...) or immunoglobulins (viral or bacterial antibodies, auto-antibodies...) and even both viral antigens and antibodies (HIV virology). The use of monoclonal antibodies allowed, through their specificity for a single epitope of the target molecule, the development of increasingly sophisticated immunoassays. In particular, the use of monoclonal antibodies with microarrays permits the simultaneous determination of various proteins (inflammatory profile, cardiac profile, specifics IgE...) quickly and accurately. Very important tools in the clinical laboratory, immunoassays techniques are, however, subject to various analytical interferences which may be responsible for significant changes in the test results.

[Vitamin D2 or vitamin D3?]. / Vitamine D2 ou vitamine D3?

PURPOSE: Nearly one billion people around the world are deficient in vitamin D and need to be supplemented. Vitamin D is available in medicines and fortified foods. It is available in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). KEY POINTS: The pharmacopeiae consider these steroid hormones as equivalent and interchangeable. However, several studies have showed that serum level of 25(OH)D is increased more effectively with vitamin D3 than vitamin D2. Vitamin D2 has shorter plasma half-life and a lower affinity for the vitamin D binding protein, the hepatic vitamin D hydroxylase and the vitamin D receptor. CONCLUSION: Vitamin D2 should not be regarded anymore as suitable for supplementation or fortification. Currently though, it is still the most used in some countries such as Portugal and Australia.