title: Dried blood spot measurement: application in tacrolimus monitoring using limited sampling strategy and abbreviated AUC estimation.
abstract: Dried blood spot (DBS) sampling and high-performance liquid chromatography tandem-mass spectrometry have been developed in monitoring tacrolimus levels. Our center favors the use of limited sampling strategy and abbreviated formula to estimate the area under concentration-time curve (AUC(0-12)). However, it is inconvenient for patients because they have to wait in the center for blood sampling. We investigated the application of DBS method in tacrolimus level monitoring using limited sampling strategy and abbreviated AUC estimation approach. Duplicate venous samples were obtained at each time point (C(0), C(2), and C(4)). To determine the stability of blood samples, one venous sample was sent to our laboratory immediately. The other duplicate venous samples, together with simultaneous fingerprick blood samples, were sent to the University of Maastricht in the Netherlands. Thirty six patients were recruited and 108 sets of blood samples were collected. There was a highly significant relationship between AUC(0-12), estimated from venous blood samples, and fingerprick blood samples (r(2) = 0.96, P < 0.0001). Moreover, there was an excellent correlation between whole blood venous tacrolimus levels in the two centers (r(2) = 0.97; P < 0.0001). The blood samples were stable after long-distance transport. DBS sampling can be used in centers using limited sampling and abbreviated AUC(0-12) strategy as drug monitoring.
authors.affiliation: Renal Unit, Department of Medicine, Queen Elizabeth Hospital, Hong Kong, China. simoncycheung@gmail.com
authors.forename: Chi Yuen
authors.initials: CY
authors.lastname: Cheung
authors.forename: Jaques
authors.initials: J
authors.lastname: van der Heijden
authors.forename: Karin
authors.initials: K
authors.lastname: Hoogtanders
authors.forename: Maarten
authors.initials: M
authors.lastname: Christiaans
authors.forename: Yan Lun
authors.initials: YL
authors.lastname: Liu
authors.forename: Yiu Han
authors.initials: YH
authors.lastname: Chan
authors.forename: Koon Shing
authors.initials: KS
authors.lastname: Choi
authors.forename: Afke
authors.initials: A
authors.lastname: van de Plas
authors.forename: Chi Chung
authors.initials: CC
authors.lastname: Shek
authors.forename: Ka Foon
authors.initials: KF
authors.lastname: Chau
authors.forename: Chun Sang
authors.initials: CS
authors.lastname: Li
authors.forename: Johannes
authors.initials: J
authors.lastname: van Hooff
authors.forename: Leo
authors.initials: L
authors.lastname: Stolk
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001800:Blood Specimen Collection; D002851:Chromatography, High Pressure Liquid; D016903:Drug Monitoring / Q000379:methods*; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics*; D016030:Kidney Transplantation; D008875:Middle Aged; D016559:Tacrolimus / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus