Dried blood spot measurement: application in tacrolimus monitoring using limited sampling strategy and abbreviated AUC estimation
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 (AUC0–12). 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 (C0, C2, and C4). 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 AUC0–12, estimated from venous blood samples, and fingerprick blood samples (r2 = 0.96, P < 0.0001). Moreover, there was an excellent correlation between whole blood venous tacrolimus levels in the two centers (r2 = 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 AUC0–12 strategy as drug monitoring.
Document Type: Research Article
Affiliations: 1: Renal Unit, Department of Medicine, Queen Elizabeth Hospital, Hong Kong, China 2: Department of Clinical Pharmacy, University Hospital Maastricht, Maastricht, The Netherlands 3: Department of Internal Medicine, University Hospital Maastricht, Maastricht, The Netherlands 4: Department of Pathology, Queen Elizabeth Hospital, Hong Kong, China
Publication date: February 1, 2008