[Second set method for determining the immunogenicity of heart valves]

Area of Science:

• Biomaterials Science
• Immunology
• Tissue Engineering

Background:

• Heart valve tissue requires effective fixation for transplantation.
• Glutaraldehyde is a common fixative but can cause immunogenic reactions.
• Investigating methods to reduce the immunogenicity of fixed heart valves is crucial for improving transplant outcomes.

Purpose of the Study:

• To evaluate the immunogenicity of heart valves treated with a proteolytic enzyme and glutaric aldehyde.
• To compare this treatment's immunogenicity with valves treated with glutaric aldehyde alone.
• To determine if enzyme pretreatment reduces recipient immune response and tissue calcification.

Main Methods:

• The
• second set
• method was employed using inbred rats.
• Heart valves were treated with a proteolytic enzyme followed by glutaric aldehyde (0.2-0.5%).
• A control group received valves treated with 0.5% glutaric aldehyde alone (Hancock's method).

Main Results:

• Valves treated with enzyme and glutaric aldehyde did not induce body sensitization.
• Valves treated with glutaric aldehyde alone showed signs of immunologic response in recipients.
• Calcification of valvular tissue was observed 70 days post-subcutaneous implantation in the glutaric aldehyde-only group.

Conclusions:

• Pretreatment of heart valves with a proteolytic enzyme can significantly reduce their immunogenicity.
• This enzyme pretreatment appears to prevent the adverse immune responses and calcification seen with glutaric aldehyde fixation alone.
• Enzyme-assisted fixation offers a promising strategy for developing less immunogenic bioprosthetic heart valves.