Aluminium in allergen-specific subcutaneous immunotherapy--a German perspective

Area of Science:

• Toxicology
• Immunology
• Public Health

Background:

• Humans experience increasing aluminum bioavailability, leading to body burden accumulation in organs like the brain, lungs, and bones.
• Aluminum toxicity is linked to neurological disorders, yet aluminum salts are widely used as safe adjuvants in prophylactic vaccinations.
• Subcutaneous immunotherapy (SCIT) involves repeated injections with higher aluminum adjuvant doses than vaccines, raising concerns about cumulative exposure.

Purpose of the Study:

• To review the safety of aluminum adjuvants in long-course subcutaneous immunotherapy (SCIT).
• To highlight the need for updated regulatory guidelines on cumulative aluminum exposure from SCIT.
• To discuss methods for measuring and reducing aluminum accumulation in patients undergoing SCIT.

Main Methods:

• Literature review of aluminum bioavailability, toxicity, and adjuvant use in vaccines and immunotherapy.
• Analysis of current regulatory limits for aluminum in vaccines versus immunotherapy.
• Discussion of potential health risks associated with high cumulative aluminum doses from SCIT.

Main Results:

• While prophylactic vaccines have a favorable benefit-risk profile for aluminum adjuvants, SCIT presents a significantly higher cumulative aluminum dose.
• Current regulatory frameworks do not adequately address cumulative aluminum thresholds for long-course immunotherapy.
• High aluminum levels from SCIT may lead to focal accumulation and potential toxicity, particularly concerning long-term health effects.

Conclusions:

• The safety of aluminum adjuvants in long-course SCIT requires further investigation and transparency from health authorities.
• There is a need for revised regulatory guidance on cumulative aluminum exposure limits in immunotherapy.
• Developing methods to monitor and mitigate aluminum accumulation in SCIT patients is crucial for patient safety.