Predictability of Capillary Blood Spot Toward Venous Whole Blood Sampling for Therapeutic Drug Monitoring of Tacrolimus in Solid Organ Transplant Recipients

VAMS microsampling found no significant difference from venous blood for tacrolimus in paediatric patients; samples were stable for 14 days, with average difference between paired at-home samples of 0.12 ± 0.94 ng/mL.

VAMS and parallel-reaction-monitoring mass spectrometry for tacrolimus trough measurements at home in paediatric heart-transplant patients — Zhao et al., J. Mass Spectrometry and Advances in the Clinical Lab · source ↗

• vams
• venous-agreement
• acceptability
• blood
• dbs
• tdm
• self-collection
• dried
• capillary
• pediatric
• immunosuppressants
• validation

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.

Multi-Matrix LC-MS/MS Validation of Methotrexate Polyglutamates: Comparison of VAMS, DBS, and Conventional Blood Sampling in Rheumatoid Arthritis — Kocur et al., International journal of molecular sciences · source ↗

• vams
• venous-agreement
• neoteryx-mitra
• blood
• dbs
• tdm
• dried
• capillary
• immunosuppressants
• validation

In children with SLE, VAMS finger-prick capillary blood gave haematocrit-adjusted MPA and MPAG concentrations indistinguishable from plasma, and the AUC from VAMS derived plasma-equivalent concentrations matched plasma AUC with R2 0.97. This supports accurate pharmacokinetically guided dosing of MMF using only three timed capillary microsamples.

Volumetric Absorptive Microsampling Combined with Mass Spectrometry to Support Pharmacokinetically-Guided Precision Dosing of Mycophenolate Mofetil in Pediatric Lupus Nephritis Patients — Zhao et al., The journal of applied laboratory medicine (paywalled) · source ↗

• vams
• venous-agreement
• blood
• tdm
• haematocrit
• dried
• capillary
• pediatric
• immunosuppressants
• validation

The study validated a VAMS-based LC-MS/MS method for measuring sirolimus levels, showing it was clinically equivalent to the standard whole blood method and suitable for therapeutic drug monitoring in paediatric transplant patients, supporting the use of decentralised microsampling for this purpose.

Personalization of pharmacotherapy with sirolimus based on volumetric absorptive microsampling (VAMS) in pediatric renal transplant recipients-from LC-MS/MS method validation to clinical application — Kocur et al., Pharmacological reports : PR · source ↗

• vams
• venous-agreement
• neoteryx-mitra
• blood
• tdm
• haematocrit
• dried
• capillary
• pediatric
• immunosuppressants
• validation

A study of 50 paediatric renal transplant recipients found that a validated VAMS LC-MS/MS method for tacrolimus showed high correlation with the reference method over 0.5–60 ng/mL, with minimal haematocrit effect.

Therapeutic Drug Monitoring of Tacrolimus Based on VAMS in Renal Transplant Pediatric Recipients — LC-MS/MS Method, Hematocrit Effect, and Clinical Application — Kocur et al., Pharmaceutics · source ↗

• vams
• venous-agreement
• neoteryx-mitra
• blood
• tdm
• haematocrit
• dried
• capillary
• pediatric
• immunosuppressants
• validation