Abstract
Alpha-gal syndrome (AGS) is an uncommon IgE-mediated allergy to mammalian-derived products, caused by sensitization to the oligosaccharide galactose-α-1,3-galactose (alpha-gal) after tick exposure. Although AGS is best recognized for delayed anaphylaxis following ingestion of red meat, its implications for exposure to mammalian-derived biomaterials remain poorly characterized. We present an elderly woman with AGS who required transcatheter aortic valve replacement (TAVR) using a bovine bioprosthesis. An 84-year-old woman with serologically confirmed AGS following a Lone Star tick bite in 2012 presented with symptomatic severe aortic stenosis. Her clinical history included multiple allergic reactions to beef, persistently elevated IgE to beef, pork, and lamb, and a specific alpha-gal IgE >100 kU/L. Following a multidisciplinary evaluation, she was not considered a candidate for a mechanical valve. A prophylactic regimen was implemented, including cetirizine, omalizumab, and 60 mg prednisone 6 h prior to TAVR. The procedure was successfully performed with a bovine-derived bioprosthetic valve. Perioperative tryptase levels remained within normal range (5.2 µg/L), and no hypersensitivity reactions occurred. Postoperatively, prednisone was tapered, while fexofenadine and omalizumab were continued for 6 months. This case highlights that bioprosthetic valve replacement can be safely performed in AGS patients through multidisciplinary planning and individualized prophylaxis strategies. Further data are needed to develop standardized perioperative management protocols for this rare but clinically significant condition.