The theophylline method of the Abbott "Vision" analyzer evaluated

Area of Science:

• Clinical Chemistry
• Analytical Toxicology
• Pharmacokinetics

Background:

• Theophylline is a critical medication requiring precise therapeutic drug monitoring.
• Accurate and reliable analytical methods are essential for effective theophylline therapy.
• Evaluating new analytical platforms is crucial for improving patient care.

Purpose of the Study:

• To assess the analytical performance of the Abbott Vision analyzer for theophylline measurement.
• To determine the interference effects of common endogenous substances on the assay.
• To compare the Vision method with an established method (TDX) and evaluate sample matrix effects.

Main Methods:

• Analytical performance evaluation including precision and linearity.
• Interference studies with bilirubin, triglycerides, and hemoglobin.
• Method comparison study using Abbott Vision and TDX analyzers.
• Assessment of sample matrix effects (serum, plasma, whole blood, capillary blood).

Main Results:

• Excellent within-day (1.8-3.1%) and between-day (3.5-4.8%) precision for theophylline measurement.
• No significant interference from bilirubin or triglycerides; minimal interference (<10%) from hemoglobin at 1 g/L.
• High correlation (r=0.98) with the TDX method, with minimal bias (y = 0.978x - 0.270 mg/L).
• Comparable results across serum, plasma, whole blood, and capillary blood samples.

Conclusions:

• The Abbott Vision analyzer demonstrates robust analytical performance for theophylline quantification.
• The method is reliable for various sample types, including capillary blood from finger sticks, simplifying sample collection.
• The Vision analyzer is a suitable tool for therapeutic drug monitoring of theophylline.