title: [Assay of plasma fibronectin in clinical biology: comparison of nephelometric and turbidimetric technics].
abstract: The aim of this study was to determine the optimal conditions for the assay of plasma Fn by laser nephelometry, to compare the nephelometric and turbidimetric techniques and to confirm the influence of various parameters on the Fn concentration. The results reveal that both techniques are sensitive (threshold of sensitivity: 20 mg/l with laser nephelometry, 125 mg/l with turbidimetry), reproducible (coefficient of variation of less than 10 p. cent), specific, simple and rapid. The interpretation of the results must take into account the influence of various factors on the Fn concentration. Fn is present in lower concentrations in the serum and the percentage of serum Fn to the plasma concentration varies from one sample to another in the same patient. The optimal conditions for the assay include collection of the plasma on EDTA, storage of the samples at - 20 degrees C and incubation of the sample at 37 degrees C prior to the assay. There is a relationship between the concentration of Fn and the sex and age of the subject. There is a significant difference between the sexes between the ages of 18 and 40, which is no longer seen after the age of 50. The ability to assay plasma Fn by rapid, specific and sensitive techniques enables us to evaluate the capacity of response of the reticulo-endothelial system in conditions of severe sepsis.
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation; D001793:Blood Preservation; D005260:Female; D005353:Fibronectins / Q000097:blood*; D005615:Freezing; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*
chemical_list: D000925:Anticoagulants; D005353:Fibronectins
vernacular_title: Dosage de la fibronectine plasmatique en biologie clinique: comparaison des techniques néphélométrique et turbidimétrique.