[Comparative study of 3 technics for the determination of plasma fibronectin. Results in the normal subject]

Three different techniques (electro-immunodiffusion: EIA, laser nephelemetry and competitive enzymo-assay: CELIA) were compared in order to select an accurate and reproducible assay of plasma fibronectin that could be used in testing large numbers of samples. Nephelemetry, gave results similar to the EIA and CELIA in assays performed with samples from 40 healthy subjects and was used to determine the plasma concentration of fibronectin in 182 male and female blood donors, ranging in age from 18 to 60. The results demonstrate a great variability in plasma fibronectin levels and show that the values are significantly lower in women, 322.9 +/- 94.7 mg/l, compared to 360.8 +/- 97.6 mg/l for men and increase with age. We conclude that the plasma fibronectin levels in various diseases must be interpreted with caution and that it seems more interesting to study the variations of values in comparison with the clinical evolution of the patients.