Alpha-Gal Syndrome Allergy to Intravitreal Administration of Anti-Vascular Endothelial Growth Factor Agents.
To describe a case of allergic reaction to intravitreal (IVT) injection of antivascular endothelial growth factor (anti-VEGF) medications in patients with alpha-gal syndrome. A single case was evaluated. A 57-year-old woman with a known diagnosis of alpha-gal syndrome was evaluated. Clinical presentation, prior treatment history, and response to different anti-VEGF agents were reviewed. The patient presented with worsening vision in her right eye due to a subfoveal choroidal neovascular membrane secondary to neovascular age-related macular degeneration in the right eye. She had experienced a systemic allergic reaction following an IVT injection of bevacizumab, but subsequently tolerated ranibizumab without any adverse effects, resulting in improvement in her vision. Bevacizumab, aflibercept, and faricimab are recombinant immunoglobulins produced by DNA technology in Chinese hamster ovary cells, which may contain galactose-α-1,3-galactose (alpha-gal), a potential allergen for patients with alpha-gal syndrome. Patients with alpha-gal syndrome may develop allergic reactions to certain IVT anti-VEGF agents derived from mammalian expression systems. Ranibizumab, produced using an expression and lacking alpha-gal, seems to be a safe and effective option for patients with alpha-gal syndrome requiring IVT anti-VEGF therapy.