Quantification of Alpha-Gal Expression in Commercial BioProsthetic Heart Valves and Its Potential Mitigation.

Background and Aims: Bioprosthetic heart valves (BHVs) are inherently susceptible to structural degeneration, driven by a combination of mechanical stress, lipid infiltration, glutaraldehyde-induced crosslinking instability, and progressive calcification. Recent evidence has implicated the αGal antigen (galactose-α-1,3-galactose) as an additional contributor to BHV deterioration through activation of innate immune pathways. The present study aims to: 1) perform a quantitative assessment of the residual presence of xenoantigens, specifically αGal, in a range of commercial BHV models; 2) evaluate the efficacy of an experimental polyphenol-based treatment in neutralizing these antigenic determinants; and 3) investigate the long-term stability of glutaraldehyde fixation concerning the potential re-exposure of αGal epitopes. Methods: Twelve distinct BHV models were subjected to in vitro analysis for αGal antigen quantification both before and following application of an experimental polyphenol treatment. Additionally, glutaraldehyde-fixed bovine pericardial tissues were incubated in a physiologically mimetic, blood-like environment for up to 9 years in real-time to simulate the long-term behavior of BHV materials and assess antigen unmasking associated with glutaraldehyde degradation. Results: The average count of the αGal epitope in original pericardial valve models was 4.18 ± 0.72 × 10 Conclusion: The data confirm that commercially available BHVs retain a substantial immunogenic burden attributable to αGal xenoantigens. Importantly, the overtime degradation of glutaraldehyde crosslinks facilitates the gradual re-exhibition of these epitopes, potentially undermining long-term valve performance. The pronounced efficacy of polyphenol-based treatment in inhibiting αGal antigens highlights its promise as a biocompatibility-enhancing pretreatment strategy for next-generation BHVs.