Dried plasma spot–based liquid chromatography–tandem mass spectrometry for the quantification of methotrexate in human plasma and its application in therapeutic drug monitoring

Abstract

Methotrexate, a folic acid antitumor drug, is widely used to treat childhood acute lymphoblastic leukemia. Therapeutic drug monitoring is crucial for adjusting the dosage of methotrexate according to its plasma concentration and reducing adverse effects. Micro‐sampling strategies, like dried plasma spot, is an attractive but underutilized method that has the desired features of easy collection, storage, and transport, and overcomes known hematocrit issues in dried blood spot analysis. This study describes a dried plasma spot–based liquid chromatography–tandem mass spectrometry method for quantification of methotrexate. The assay showed good linearity over 30–2000 ng/mL (R2 ≥ 0.995) as well as excellent precision (0.6–9.3%) and accuracy (89.2–108.3%). Methotrexate was extracted from dried plasma spot and wet plasma samples with recoveries greater than 92.1%, and no significant matrix effect was observed. A comparison of dried plasma spot and wet plasma concentrations was assessed in 27 patients treated with methotrexate and Passing–Bablok regression coefficients showed that no significant difference between the two methods. The Bland–Altman plots showed similar agreement between the methods, indicating that the proposed dried plasma spot sampling method is an effective way to monitor the concentration of methotrexate in human plasma.

Capillary-in-Capillary Electrospray Ionization (CC-ESI) Source Enabling Convenient Sampling and Quantitative Analysis for Point-of-Care Testing

“…With ultrahigh sensitivity, specificity, and analysis speed, mass spectrometry (MS) has been becoming an exciting analytical technology for increasingly more clinical applications, including identification of microbes, − newborn screening (NBS), and quantification of therapeutic drugs. , Nowadays, nearly all clinical MS analyses are performed using laboratory-scale mass spectrometers typically coupled with a gas chromatograph (GC) or liquid chromatograph (LC), which is always labor-intensive and time-consuming. As a result, these MS techniques are limited to only in-lab applications and cannot meet the increasing demands of in situ clinical analysis, especially point-of-care testing (POCT).…”

Blood microsampling technologies: Innovations and applications in 2022

“…28 In another study in patients with lymphoblastic leukaemia, DPS and wet plasma concentrations of methotrexate were found to have no statistically significant difference. 117 However, DPS from Telimmune cards have been shown…”

“…Evaluation of methotrexate polyglutamates in different matrices including plasma, RBCs, peripheral blood mononuclear cells and venous whole blood revealed that VAMS can be used for accurate TDM analysis only if sampling is done immediately before the next dose of methotrexate to ensure that concentrations are not overestimated 28 . In another study in patients with lymphoblastic leukaemia, DPS and wet plasma concentrations of methotrexate were found to have no statistically significant difference 117 . However, DPS from Telimmune cards have been shown to produce inconsistent filtration across different cards, in the study by Tang et al., for the quantification of giredestrant, stipulating the need for further optimization to ensure good accuracy and precision 118 .…”

“… 28 In another study in patients with lymphoblastic leukaemia, DPS and wet plasma concentrations of methotrexate were found to have no statistically significant difference. 117 However, DPS from Telimmune cards have been shown to produce inconsistent filtration across different cards, in the study by Tang et al., for the quantification of giredestrant, stipulating the need for further optimization to ensure good accuracy and precision. 118 Various LC‐MS/MS assays for the VAMS technology have been developed and validated for the quantification of other chemotherapy drugs and its metabolites such as 5‐fluorouracil, capecitabine, CP, 4‐OHCP and several tyrosine kinase inhibitors (TKIs).…”

A high‐throughput liquid chromatography‐tandem mass spectrometry method for simultaneous determination of direct oral anticoagulants in human plasma

“…However, several disadvantages should be recognized, such as calibration to the particular drug, the imprecise results at low plasma levels, and none of the methods being specific enough for quantifying all DOACs in a single run [10]. LC-MS/MS presents a golden standard and powerful technique for multiple drug analysis [11][12][13], including DOACs monitoring in preclinical drug development [14,15]. Due to the high degree of specificity, sensitivity, and selectivity over the coagulation-based assays, the use of LC-MS/MS in clinical laboratories has significantly increased in past years for DOAC monitoring [16].…”