title: Diagnosing protein S deficiency: analytical considerations.
abstract: The anticoagulant protein S functions as a cofactor to activated protein C (APC) in the degradation of procoagulant factors Va and VIIIa. In plasma, approximately 70% of circulating protein S is bound to the complement regulatory C4b-binding protein. Deficiency of protein S is an established risk factor for thrombosis, but diagnosing such a condition is not a trivial task. Most protein S deficiencies are quantitative and only few qualitative deficiencies have been characterized. This review is focused on various aspects of protein S: the gene, the protein molecule, and measurement of the protein in plasma. Development of new methods and strict protocols for standardization and sample handling will considerably improve the ability to predict protein S deficiency.
authors.affiliation: Department of Clinical Chemistry, Lund University, University Hospital, SE-205 02 Malmö, Sweden. Kristina.Persson@klkemi.mas.lu.se
authors.forename: Kristina E M
authors.initials: KE
authors.lastname: Persson
authors.forename: Björn
authors.initials: B
authors.lastname: Dahlbäck
authors.forename: Andreas
authors.initials: A
authors.lastname: Hillarp
mesh_terms: D002893:Chromosomes, Human, Pair 3 / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008954:Models, Biological; D008957:Models, Genetic; D017293:Protein S / Q000032:analysis* / Q000235:genetics; D018455:Protein S Deficiency / Q000175:diagnosis*; D011544:Pseudogenes; D019851:Thrombophilia / Q000175:diagnosis
chemical_list: D017293:Protein S