Volumetric absorptive microsampling and dried blood spot microsampling vs. conventional venous sampling for tacrolimus trough concentration monitoring

Veenhof, H., Koster, R. A., Junier, L. A. T., Berger, S. P., Bakker, S. J. L. & Touw, D. J., 2020, In : Clinical chemistry and laboratory medicine. 58, 10, p. 1687-1695 9 p.

Research output: Contribution to journalArticleAcademicpeer-review

Objectives: Monitoring tacrolimus blood concentrations is important for preventing allograft rejection in transplant patients. Our hospital offers dried blood spot (DBS) sampling, giving patients the opportunity to sample a drop of blood from a fingerprick at home, which can be sent to the laboratory by mail. In this study, both a volumetric absorptive microsampling (VAMS) device and DBS sampling were compared to venous whole blood (WB) sampling. Methods: A total of 130 matched fingerprick VAMS, fingerprick DBS and venous WB samples were obtained from 107 different kidney transplant patients by trained phlebotomists for method comparison using Passing-Bablok regression. Bias was assessed using Bland-Altman. A multidisciplinary team pre-defined an acceptance limit requiring ï80% of all matched samples within 15% of the mean of both samples. Sampling quality was evaluated for both VAMS and DBS samples. Results: 32.3% of the VAMS samples and 6.2% of the DBS samples were of insufficient quality, leading to 88 matched samples fit for analysis. Passing-Bablok regression showed a significant difference between VAMS and WB, with a slope of 0.88 (95% CI 0.81-0.97) but not for DBS (slope 1.00; 95% CI 0.95-1.04). Both VAMS (after correction for the slope) and DBS showed no significant bias in Bland-Altman analysis. For VAMS and DBS, the acceptance limit was met for 83.0% and 96.6% of the samples, respectively. Conclusions: VAMS sampling can replace WB sampling for tacrolimus trough concentration monitoring, but VAMS sampling is currently inferior to DBS sampling, both regarding sample quality and agreement with WB tacrolimus concentrations. c 2020 Daan J. Touw et al., published by De Gruyter.

Original languageEnglish
Pages (from-to)1687-1695
Number of pages9
JournalClinical chemistry and laboratory medicine
Issue number10
Early online date15-May-2020
Publication statusPublished - 2020

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