[Biological variations and reference values of transferrin, immunoglobulin A and orosomucoid]

To explain laboratory test results, it is necessary to know for each parameter the biological variation factors and the reference values. The principal biological variations factors for transferrin, IgA and orosomucoid (age, sex, body weight, exercise, puberty, menstrual cycle, professional class and work conditions) have been studied on a sample of the population who have come to the Center for Preventive Medicine (Vandoeuvre-Lès-Nancy, France) for a health check-up (males and females, 4-60 years). We have assembled bibliographical data concerning the other main variations factors. Our results (variations calculated on the medians) and literature results (variations calculated on the medians or on the means) are presented together. These are respectively: 1. For transferrin: age (new-born/20-30 years: -29 to -71%, 50-60 years/20-30 years: -15%), menstrual cycle (+15%), pregnancy (+37 to +70%), exercise (+9 to +13%), oral contraceptives (+10 to +62%), medications (danazol: +60%, testosterone: -13%, D-penicillamine: -13 to -30%, L-asparaginase: -68%); 2. For IgA: age (new-born/20-30 years: -98 to 100%, 3-5 years/20-30 years: about -50%, 50-60 years/20-30 years: up to +60%), sex (men/women: up to +30%), exercise (+14%), pregnancy (-20%), obesity (+30%), season (winter/summer: +10 to +14%, in Africa humid season/dry season: +20%), oral contraceptives (-11 to -40%), medications (L-asparaginase: +36 to +60%), socio-economical factors (black/white: +20 to +75%); 3. For orosomucoid: age (new-born/20-30 years: -70 to -95%, 60-80 years/20-30 years: up to +50%), sex (men/women: up to +15%), obesity (+26%), menstrual cycle (+14%), pregnancy (-20 to -30%), oral contraceptives (-21 to -36%), medications (L-asparaginase: +17%, anabolic steroids: +68%). We determined the three proteins reference values with a nephelometric method.