ACQUITY™ UPLC™ I-Class/Xevo™ TQ Absolute IVD System: Analytical Performance for Immunosuppressive Agents

Significance of the Topic

Therapeutic drug monitoring of immunosuppressive agents is essential for transplant patient care, ensuring optimal dosing to prevent rejection and minimize toxicity. High-throughput, sensitive, and precise analytical platforms are critical in clinical laboratories to deliver reliable results within tight turnaround times.

Goals and Study Overview

This application note evaluates the analytical performance of the Waters ACQUITY UPLC I-Class/Xevo TQ Absolute IVD System for quantifying four key immunosuppressive compounds—cyclosporine, everolimus, sirolimus, and tacrolimus—in human whole blood samples. The study aims to determine linear range, sensitivity, precision, and accuracy relative to external quality assessment targets.

Methodology and Instrumentation

Sample Preparation

50 µL whole blood was subjected to protein precipitation using zinc sulfate and acetonitrile, followed by centrifugation to obtain clear supernatants.

Liquid Chromatography Conditions

• Column: ACQUITY UPLC HSS C18 SB, 1.8 µm, 2.1 × 30 mm
• Mobile Phase A: 2 mM ammonium acetate + 0.1% formic acid in water
• Mobile Phase B: 2 mM ammonium acetate + 0.1% formic acid in methanol
• Flow Rate and Gradient: 0.4 mL/min; 50% B (0.2 min), ramp to 100% B (0.4 min), hold (0.6 min), re-equilibrate at 50% B (0.6 min)

Mass Spectrometry Conditions

• Instrument: Xevo TQ Absolute IVD, ESI positive mode
• Acquisition: Multiple reaction monitoring (MRM)
• Resolution: MS1 and MS2 at 0.75 FWHM

Data Handling

System control and data processing were performed using MassLynx IVD v4.2 and TargetLynx Application Manager.

Key Results and Discussion

• All four analytes exhibited linear calibration curves with correlation coefficients (r2) greater than 0.995.
• Lower limit of quantification (LLOQ) was defined by signal-to-noise ratio >10, enabling detection at clinically relevant concentrations.
• Intra- and inter-day precision (n=25 across five days) demonstrated total coefficient of variation below 10% for quality control samples.
• External quality assessment (EQA) mean bias against LC-MS trimmed means was within ±8%, indicating excellent accuracy.
• Fast chromatographic separation achieved baseline resolution in under two minutes, supporting high sample throughput.

Benefits and Practical Applications

• Rapid analysis cycle enhances laboratory efficiency and reduces sample backlog.
• High sensitivity and precision support accurate therapeutic monitoring.
• IVD compliance of the system ensures standardized performance in regulated environments.
• Applicability to routine clinical testing of immunosuppressants in transplant programs.

Future Trends and Applications

Advances in IVD platforms are expected to integrate automated sample preparation, expand multiplexed analyte panels, and leverage AI-driven data analysis for decision support. Miniaturized UPLC-MS/MS setups may facilitate point-of-care testing and remote monitoring in telemedicine settings.

Conclusion

The ACQUITY UPLC I-Class/Xevo TQ Absolute IVD System delivers robust, sensitive, and reproducible quantification of key immunosuppressive drugs in whole blood. Its rapid throughput and compliance with in vitro diagnostic requirements make it a valuable tool for clinical laboratories performing therapeutic drug monitoring.

Reference

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