title: Capillary blood collected on volumetric absorptive microsampling (VAMS) device for monitoring hydroxychloroquine in rheumatoid arthritis patients.
abstract: A novel technique for collection of capillary blood, termed volumetric absorptive microsampling (VAMS), has been recently cleared by the FDA for collection of human blood. VAMS absorbs a fixed volume of blood (10μl) and overcomes area bias and homogeneity issues associated with dried blood spot (DBS). This study is the application of VAMS for therapeutic drug monitoring (TDM) in human capillary blood. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) workflow for analysis of VAMS sample was developed and validated. Concentration of hydroxychloroquine (HCQ) and its metabolites, desethylhydroxychloroquine (DHCQ), desethylchloroquine (DCQ), and bisdesethylchloroquine (BDCQ), in capillary blood on VAMS sampler were compared to those in venous blood in rheumatoid arthritis patients. Feasibility of capillary blood collected on both VAMS and DBS card were evaluated on patients. Stability of dried capillary blood on VAMS was also examined. Our results established that VAMS is a simple and accurate sampling technique that delivers the benefits of DBS sampling while overcoming the issues associated with hematocrit and homogeneity. It requires a small blood volume, simplifies sample logistics management, and may allow sample collection in the patient's home setting.
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA. Electronic address: yqu@exagen.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Kelley
authors.initials: K
authors.lastname: Brady
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Apilado
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: O'Malley
authors.affiliation: Arthritis Care and Research Center, Poway, CA, USA.
authors.forename: Smitha
authors.initials: S
authors.lastname: Reddy
authors.affiliation: Center for Arthritis and Rheumatologic Excellence, Chula Vista, CA, USA.
authors.forename: Puja
authors.initials: P
authors.lastname: Chitkara
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ibarra
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Roberta Vezza
authors.initials: RV
authors.lastname: Alexander
authors.affiliation: Research and Development, Exagen Diagnostics Inc., Vista, CA, USA.
authors.forename: Thierry
authors.initials: T
authors.lastname: Dervieux
mesh_terms: D001172:Arthritis, Rheumatoid; D001800:Blood Specimen Collection; D059788:Dried Blood Spot Testing; D006801:Humans; D006886:Hydroxychloroquine; D053719:Tandem Mass Spectrometry
chemical_list: D006886:Hydroxychloroquine
keywords: Dried blood spot; Hydroxychloroquine; LC–MS/MS; Rheumatoid arthritis; Therapeutic drug monitoring; Volumetric absorptive microsampling