Specific micro-radioimmunoassay for prednisolone in serum

Area of Science:

• Biochemistry
• Analytical Chemistry
• Pharmacology

Background:

• Accurate quantification of prednisolone is crucial for therapeutic drug monitoring.
• Existing methods may face interference from other glucocorticoids and drug metabolites.
• Development of sensitive and specific assays is essential for clinical applications.

Purpose of the Study:

• To develop and validate a novel radioimmunoassay for determining serum prednisolone concentrations.
• To address and overcome interference issues from prednisolone-21-phosphate and endogenous glucocorticoids.
• To compare the performance of the new assay with established analytical techniques.

Main Methods:

• Utilized Iodine-125 (125I) radioimmunoassay with magnetizable cellulose-coupled antiserum.
• Implemented dichloromethane extraction at pH 7.4 to remove prednisolone-21-phosphate interference.
• Employed selective chemical derivatization using Girard's Reagent T to eliminate endogenous glucocorticoid interference.
• Analyzed serum samples with a minimal volume of 10 microliters.

Main Results:

• The developed radioimmunoassay method demonstrated effective determination of prednisolone in small serum volumes.
• Interference from prednisolone-21-phosphate and endogenous glucocorticoids was successfully mitigated.
• Assay results showed strong correlation with an established liquid-chromatographic method.
• The method proved reliable for distinguishing prednisolone from its metabolites.

Conclusions:

• The novel 125I radioimmunoassay provides a sensitive and specific method for serum prednisolone measurement.
• The assay's ability to handle interference makes it a valuable tool in clinical settings.
• This method offers a reliable alternative to liquid chromatography for prednisolone quantification.
• The technique facilitates accurate therapeutic drug monitoring of prednisolone therapy.