Minimally Invasive Therapeutic Drug Monitoring of Immunosuppressants in Children with Kidney Diseases: Validation of Fingerstick Sampling Using LC-MS/MS

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

This study validated a method for monitoring mycophenolic acid in paediatric patients, demonstrating that quantitative dried plasma spots achieved close agreement with venous plasma. Quantitative dried blood spots showed significant haematocrit-related bias, making the plasma-based format more suitable for decentralised monitoring.

Matrix fidelity in microsampling: Plasma-first LC-MS/MS quantification of mycophenolic acid and MPAG — Kocur et al., Journal of chromatography. B, Analytical technologies in the biomedical and life sciences (paywalled) · source ↗

• venous-agreement
• blood
• qdbs
• tdm
• haematocrit
• dried
• pediatric
• immunosuppressants
• validation