ACQUITY UPLC I-Class SM-FL/Xevo TQ-S micro IVD System: Analytical Performance for Immunosuppressive Agents

Significance of the topic

Accurate and simultaneous quantification of key immunosuppressive drugs in whole blood is critical for ensuring therapeutic efficacy and patient safety in transplant and autoimmune therapy.

Objectives and Study Overview

This study evaluates the analytical performance of the Waters ACQUITY UPLC I-Class SM-FL/Xevo TQ-S micro IVD System for simultaneous measurement of cyclosporine, everolimus, sirolimus, and tacrolimus in human whole blood samples.

Methodology

Sample preparation:

• 50 µL whole blood mixed with zinc sulfate and acetonitrile
• Centrifugation to remove proteins and particulates

Chromatographic 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
• Gradient: 50% B (0–0.2 min), 50→100% B (0.2–0.6 min), hold 100% B (0.6–1.2 min), re-equilibrate at 50% B
• Flow rate: 0.45 mL/min (initial), 0.8 mL/min during re-equilibration

Mass spectrometry conditions:

• Instrument: Xevo TQ-S micro triple quadrupole
• Ionization: ESI positive mode
• Acquisition: MRM with 0.75 FWHM resolution in MS1 and MS2

Main Results and Discussion

All four analytes showed linear calibration curves (r2 > 0.995) over clinically relevant ranges. Lower limits of quantification (LLOQ) were defined by S/N > 10 and %RSD ≤ 20%. Precision and repeatability studies across five days (n=25) demonstrated total RSD < 15%. External quality assessment against LC-MS all laboratories trimmed mean (LC-MS ALTM) indicated bias within acceptable limits. Chromatographic separation allowed detection of 25 ng/mL cyclosporine and 1 ng/mL everolimus, sirolimus, and tacrolimus in a single 1.5-minute run time.

Benefits and Practical Applications

• Simultaneous multi-analyte assessment reduces turnaround time.
• High sensitivity and precision support therapeutic drug monitoring.
• Compact workflow suitable for clinical diagnostic laboratories.

Future Trends and Opportunities

Emerging directions include automation of sample preparation, expansion to additional transplant drugs, integration with laboratory information systems, and continued miniaturization to increase throughput and reduce solvent usage.

Conclusion

The ACQUITY UPLC I-Class SM-FL/Xevo TQ-S micro IVD System delivers robust, rapid, and precise quantification of key immunosuppressive agents in whole blood, meeting stringent clinical diagnostic requirements.