Liquid chromatography-tandem mass spectrometry for therapeutic drug monitoring of immunosuppressants and creatinine from a single dried blood spot using the Capitainer® qDBS device
Deprez et al.
The finding, in our words
Deprez et al. validated LC‑MS/MS methods for four immunosuppressants and creatinine from a single 10 μL quantitative dried blood spot. With biases under 10 % and CVs below 8 %, the approach enables accurate patient‑centric therapeutic drug monitoring from capillary blood at home, mitigating the haematocrit effect through volumetric collection.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Microsampling, particularly VAMS and quantitative DBS, can enable patient-centric therapeutic drug monitoring of immunosuppressants after transplantation, allowing home self-sampling and long-term monitoring when patients live far from transplant centres. These volumetric dried formats have largely overcome the haematocrit effect and sample heterogeneity that limit conventional dried blood spots.
This review found that volumetric microsampling devices, such as Mitra, HemaPEN, HemaXis DB10, and Tasso-M20, overcome haematocrit bias, whilst Telimmune plasma separation cards enable direct plasma collection without centrifugation. These technologies support patient-centric, decentralised sampling, though the authors note that clinical validation remains limited across different drugs and patient populations.
Volumetric microsampling can enable patient-centred therapeutic drug monitoring with high patient preference and acceptable method validation for many drugs, but conversion from capillary to plasma and agreement with venous sampling varies by analyte and requires careful validation.
A validated LC-MS/MS method for everolimus using Mitra and Capitainer devices found excellent agreement between capillary microsamples and venous whole blood in 33 adult transplant recipients. The results showed high accuracy and negligible haematocrit effects, supporting the use of microsampling for decentralised therapeutic drug monitoring.
A study of 37 kidney transplant recipients found Capitainer and Mitra microsampling feasible for decentralised monitoring. Capitainer showed consistent sampling success, 92%-96%, and higher analytical accuracy than Mitra, 52%-88% success. Proportions within ±15% of venous reference for creatinine and haemoglobin were 92%-100% and 93%-100% for Capitainer, versus 79%-96% and 67%-92% for Mitra, despite small cohorts.