Automation of tacrolimus measurement on volumetric absorptive microsampling devices by tandem mass spectrometry.

Aims: An automated method for the measurement of blood tacrolimus on volumetric absorptive microsampling (VAMS) devices was developed. Materials & methods: VAMS devices prepared by the automated method were compared with those prepared by the existing manual method (n = 284; mean concentration: 8.0 µg/l; range: 0.6-18.1). Results: The performance of both methods was comparable. Passing-Bablok regression demonstrated an acceptable correlation (y = -0.449 + 1.06x). Bland-Altman analysis demonstrated acceptable agreement (mean bias: -0.007 µg/l; standard deviation: 1.536). Automation reduced operator touch time by 40 min (48-sample batch). Conclusion: Automated preparation of VAMS devices reduced touch time and improved process consistency, facilitating high-throughput testing and transformation of existing laboratory workflows. Automation did not improve precision for VAMS devices but did so for liquid blood samples.

After a kidney transplant, many patients take a drug called tacrolimus to help prevent their new kidney from being rejected. Blood levels of tacrolimus are checked regularly to ensure each patient is receiving the right dose. This means regular visits to the hospital for blood tests, which can be inconvenient and time-consuming for the patient. Microsampling devices are now available that would enable patients to collect blood from a finger prick sample, at home, and post it back to the lab for testing. However, to date, access to home sampling is limited because measuring tacrolimus from blood collected on a microsampling device relies on a manual laboratory process that is difficult to do and takes a long time. Measurement of tacrolimus from blood collected on a microsampling device can be successfully automated with a Gerstel MPS robot. The robot extracts the tacrolimus from the blood on the microsampling device and injects the resulting sample into a mass spectrometer for measurement. Two sets of microsamples were prepared. One set of samples was extracted by the robot and one set of VAMS samples was extracted manually. Tacrolimus was measured by mass spectrometry for both sets of samples and the results compared well. The automated method requires less operator input than the manual method, which will make it easier to measure large numbers of microsamples quickly and safely, increasing the number of patients who can benefit from the advantages of remote sampling.

Validation of a liquid chromatography tandem mass spectrometry method for the simultaneous determination of hydroxychloroquine and metabolites in human whole blood.

Objectives Hydroxychloroquine (HCQ) is an anti-malarial and immunomodulatory drug reported to inhibit the Corona virus, SARS-CoV-2, in vitro. At present there is insufficient evidence from clinical trials to determine the safety and efficacy of HCQ as a treatment for COVID-19. However, since the World Health Organisation declared COVID-19 a pandemic in March 2020, the US Food and Drug Administration issued an Emergency Use Authorisation to allow HCQ and Chloroquine (CQ) to be distributed and used for certain hospitalised patients with COVID-19 and numerous clinical trials are underway around the world, including the UK based RECOVERY trial, with over 1000 volunteers. The validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of HCQ and two of its major metabolites, desethylchloroquine (DCQ) and di-desethylchloroquine (DDCQ), in whole blood is described. Methods Blood samples were deproteinised using acetonitrile. HCQ, DCQ and DDCQ were chromatographically separated on a biphenyl column with gradient elution, at a flow rate of 500 µL/min. The analysis time was 8 min. Results For each analyte linear calibration curves were obtained over the concentration range 50-2000 µg/L, the lower limit of quantification (LLOQ) was 13 µg/L, the inter-assay relative standard deviation (RSD) was <10% at 25, 800 and 1750 µg/L and mean recoveries were 80, 81, 78 and 62% for HCQ, d4-HCQ, DCQ and DDCQ, respectively. Conclusion This method has acceptable analytical performance and is applicable to the therapeutic monitoring of HCQ, evaluating the pharmacokinetics of HCQ in COVID-19 patients and supporting clinical trials.

Challenging the status quo: A comparison of ion exchange chromatography with liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry methods for the measurement of amino acids in human plasma.

BACKGROUND: Plasma amino acid analysis is key to the diagnosis and monitoring of inherited disorders of amino acid synthesis, catabolism and transport. Ion exchange chromatography (IEC) is widely accepted as the gold standard method of analysis, but with the introduction of liquid chromatography tandem mass spectrometry (LC-MS/MS) and liquid chromatography mass spectrometry (LC-MS) methods, this should now be questioned. METHODS: The analytical performance of three commercially available reagent kits, Waters AccQ Tag™ ULTRA LC-MS, SpOtOn Amino Acids LC-MS/MS and Chromsystems MassChrom® Amino Acid Analysis LC-MS/MS, were evaluated and compared with Biochrom Physiological Amino Acids ion exchange chromatography. Correlation with IEC was assessed by Passing-Bablok regression, concordance correlation coefficients (CCC) and Bland-Altman analysis for 21 common amino acids. Calculation of the total error from imprecision and bias was also used to benchmark performance. RESULTS: The MassChrom® and SpOtOn kits demonstrated acceptable inter-batch imprecision (CV < 10%) and accuracy (mean bias < 10%), whereas the AccQ Tag™ ULTRA kit did not. Good correlation (CCC > 0.95) with Biochrom IEC was demonstrated for 10/21 analytes in both the MassChrom® and SpOtOn kits and 6/21 in the AccQ Tag™ ULTRA kit. CONCLUSIONS: The LC-MS assay demonstrated variable analytical performance and correlated poorly with ion exchange chromatography. Both LC-MS/MS assays demonstrated comparable analytical performance and reasonable correlation with ion exchange chromatography. They also confer practical advantages which cannot be realized by ion exchange chromatography, superior specificity and significantly faster analysis time, suggesting that ion exchange chromatography should no longer be described as the gold standard method for plasma amino acid analysis.

The child's experience of single room isolation: a literature review.

Studies have shown that people who require single room isolation while in hospital often feel lonely, sad, worried, bored and in need of information. A literature review identified only 16 papers reporting on the child's experience of isolation. Findings indicate that children feel lonely, are scared of the personal protective equipment and feel bored. Patients' parents feel guilty, worried and under increased pressure to visit their children. It is also suggested that isolation may affect child development.

The psychophysiological effects of music therapy in intensive care units.

This article reviews the evidence for using music therapy with young people who are supported by mechanical ventilation. The author argues that music therapy is essential for developing a holistic approach focusing on the developmental level of a child or young person, as well as being an inexpensive, non-pharmacological, non-invasive therapy, with significant physiological and psychological benefits. She argues that more research is needed in this area to develop a sound evidence base on which guidelines to inform practice could be based.