title: A study of Protein S antigen levels in 3788 healthy volunteers: influence of age, sex and hormone use, and estimate for prevalence of deficiency state.
abstract: Total Protein S (tPS) and free Protein S (fPS) antigen levels were measured in 3788 healthy blood donors. Men had higher levels of both parameters than women (P < 0.001). Age had no effect on tPS in men, although there was a slight reduction in fPS levels with increasing age. In women increasing age was associated with a significant increase in tPS levels (P < 0.001) but had no effect on fPS after adjustment for menopausal state. Oral contraceptive pill (OCP) use significantly lowered tPS but had no effect on fPS. In post-menopausal women, hormone replacement therapy (HRT) use had no statistically significant effect on either tPS or fPS. Donors with tPS or fPS levels in the lowest percentile (n = 56) were retested; only nine with repeat low levels were identified, eight of whom had persistently low levels over a 4-7-year follow-up. Acquired deficiency was excluded. When possible, family studies were performed, leading to an estimate of prevalence of familial PS deficiency of between 0.03% and 0.13% in the general population.
authors.affiliation: Department of Haematology, Glasgow Royal Infirmary, Scotland, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Dykes
authors.forename: I D
authors.initials: ID
authors.lastname: Walker
authors.forename: A D
authors.initials: AD
authors.lastname: McMahon
authors.forename: S I
authors.initials: SI
authors.lastname: Islam
authors.forename: R C
authors.initials: RC
authors.lastname: Tait
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000941:Antigens / Q000097:blood*; D016001:Confidence Intervals; D003278:Contraceptives, Oral, Hormonal / Q000008:administration & dosage; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017293:Protein S / Q000032:analysis / Q000276:immunology*; D018455:Protein S Deficiency / Q000453:epidemiology* / Q000235:genetics; D012016:Reference Values; D012606:Scotland / Q000453:epidemiology; D012737:Sex Factors; D012907:Smoking
chemical_list: D000941:Antigens; D003278:Contraceptives, Oral, Hormonal; D017293:Protein S