Fully Automated Dried Blood Spot Extraction coupled to Liquid Chromatography-tandem Mass Spectrometry for Therapeutic Drug Monitoring of Immunosuppressants
Deprez & Stove
The finding, in our words
The authors developed and validated a fully automated dried blood spot extraction system coupled to LC-MS/MS for therapeutic drug monitoring of four immunosuppressants. The method showed good accuracy and reproducibility, which could reduce the burden of frequent hospital visits and venipunctures for patients on immunosuppressant therapy.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
This study validated a dried blood spot method for tacrolimus monitoring and demonstrated agreement with venous whole blood measurements in kidney transplant recipients. It also found that dried blood spot analysis of the biomarker CXCL-10 was elevated in patients experiencing rejection or infection, supporting its use for decentralised monitoring.
In matched clinical samples from rheumatoid arthritis, VAMS and DBS showed strong agreement for methotrexate polyglutamates (slopes 0.95-1.07; bias within -4.21% to 0.36%; SRCC ≥ 0.969), with up to 100% of total MTXPG results within ±20% limits; capillary microsampling agreed closely with whole blood but differed from red blood cells, indicating matrix-specific differences that must be accounted for when interpreting against RBC-based reference values.
Kocur et al., International journal of molecular sciences · source ↗
A systematic review found mixed economic evidence for microsampling in therapeutic drug monitoring; one study reported no cost reduction with DBS home-sampling, €688 versus €676, whilst another predicted savings up to 61%. The authors caution that more work is required to assess costs alongside clinical outcomes and optimise logistics for decentralised implementation.
Carland et al., British Journal of Clinical Pharmacology (paywalled) · source ↗
A 2025 review maps 28 microsampling devices, from dried spots and volumetric absorptive tips to upper-arm liquid capillary collectors, and names what a laboratory must control before their results are used: the haematocrit effect in non-volumetric dried samples, interstitial fluid from finger milking, volume, haemolysis and transport stability. Regulators on both sides of the Atlantic ask for the same two things, a device the patient can use safely and a sample fit for the test.
A dried blood spot LC-MS/MS method for voclosporin was analytically validated using volumetric sampling devices, demonstrating strong agreement with whole blood analysis across a 10-600 µg/L range. The method meets ICH M10 guidelines and allows remote therapeutic drug monitoring in kidney transplant recipients.
Metscher et al., Journal of pharmaceutical and biomedical analysis (paywalled) · source ↗