Measurement of total and bioactive interleukin-2 in tissue samples by immunoaffinity-receptor affinity chromatography

Area of Science:

• Biochemistry
• Immunology
• Analytical Chemistry

Background:

• Cytokine measurement is crucial for diagnosing conditions like organ transplant rejection.
• Current methods quantify total cytokines but not their biological activity.
• Interleukin-2 (IL-2) plays a key role in immune responses and transplant outcomes.

Purpose of the Study:

• To develop a novel chromatographic system for measuring both total and bioactive IL-2.
• To differentiate between organ transplant rejection and drug-induced nephrotoxicity using IL-2 measurements.
• To assess the utility of the new system in clinical biopsy samples.

Main Methods:

• A combined immunoaffinity chromatography and immobilized receptor detection system was developed.
• High-pressure liquid chromatography with antibody-coated beads was used for IL-2 separation and concentration.
• Bioactivity was detected via molecular interactions with immobilized specific receptors.

Main Results:

• The system successfully measured total and bioactive IL-2 concentrations in renal transplant biopsy tissue extracts.
• Measurements were performed during episodes of both transplant rejection and drug-induced nephrotoxicity.
• The developed system demonstrated comparable performance to conventional bioassays and immunoassays.

Conclusions:

• The novel chromatographic system provides a method for assessing IL-2 bioactivity alongside total concentration.
• This technique can aid in distinguishing between transplant rejection and nephrotoxicity in renal transplant recipients.
• The system offers a valuable tool for the clinico-pathological diagnosis of transplant-related complications.