Matrix fidelity in microsampling: Plasma-first LC-MS/MS quantification of mycophenolic acid and MPAG

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.

Therapeutic Drug Monitoring of Everolimus Using Volumetric Absorptive Microsampling and Quantitative Dried Blood Spot Methods with LC-MS/MS in Adult Solid Organ Transplant Recipients: An Analytical and Clinical Comparative Study — Kocur et al., Molecules · source ↗

• vams
• venous-agreement
• neoteryx-mitra
• blood
• qdbs
• tdm
• haematocrit
• 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

A study of 50 paediatric renal transplant recipients found that a UHPLC-MS/MS method successfully quantified mycophenolic acid in VAMS microsampling samples over a 0.10-15 µg/mL range. However, converting microsampling results to plasma equivalents using haematocrit-based regression is required for clinical interpretation, supporting patient-centric decentralised monitoring.

Therapeutic drug monitoring of mycophenolic acid (MPA) using volumetric absorptive microsampling (VAMS) in pediatric renal transplant recipients: ultra-high-performance liquid chromatography-tandem mass spectrometry analytical method development, cross-validation, and clinical application — Kocur et al., Pharmacological reports : PR · source ↗

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