Radiolabelling of antibodies: methods and limitations

Area of Science:

• Nuclear medicine
• Immunology
• Radiochemistry

Background:

• Radioimmunoscintigraphy relies on labelled antibodies for tumor localization.
• Antibody-based imaging faces challenges due to potential degradation and fragment distribution.

Purpose of the Study:

• To outline the critical optimization parameters for developing labelled antibodies for radioimmunoscintigraphy.
• To address the unavoidable degradation of antibodies and its impact on imaging.

Main Methods:

• Investigating radionuclide selection and antibody conjugation strategies.
• Evaluating labeling techniques and the use of radioprotective agents.
• Analyzing the degradation pathways of labelled antibodies.

Main Results:

• Optimization involves balancing radionuclide choice, antibody attachment site, labeling method, and radioprotective agents.
• Both radiolytic and enzymatic degradation of antibodies occur, even under optimal conditions.
• Degraded antibody fragments distribute differently, potentially interfering with imaging of organs like the liver, kidney, and spleen.

Conclusions:

• Careful optimization is essential for effective radioimmunoscintigraphy.
• Antibody degradation is an inherent challenge that must be managed.
• Fragment distribution poses a significant obstacle for accurate scintigraphy in specific organs.