Wang Chloe, Campbell Jackie, Lea-Banks Harriet, Lee Erika
Faculty of Science and Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
Drug Allergy Clinic, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
Allergy Asthma Clin Immunol. 2025 May 7;21(1):22. doi: 10.1186/s13223-025-00964-5.
Perflutren lipid microsphere suspension, sold under the brand name Definity®, is a microbubble ultrasound contrast agent. The microspheres contain octafluoropropane (CF) gas encapsulated by an outer lipid shell of phospholipids and a polyethylene glycol (PEG)ylated phospholipid. Anaphylaxis to perflutren lipid microsphere is very rare, with only one case report clearly attributing the reaction to the PEG excipient. We report a novel case of anaphylaxis likely caused by a non-PEGylated component of Definity®.
Our patient is a healthy 54-year-old female, who underwent an exercise stress transthoracic echocardiogram using Definity® as an enhancing agent. She experienced anaphylaxis within 15 min of injection. Symptoms resolved after she was treated with diphenhydramine and epinephrine, followed by a systemic corticosteroid and ondansetron in the Emergency Department. The patient underwent allergy testing at our clinic for Definity® and various PEG-containing substances. While all PEG products tested negative, she had positive intradermal tests to Definity®. She also had negative skin prick testing to PEG 8000 and passed an oral challenge to PEG 3350, thus ruling out PEG as the causative agent of anaphylaxis.
Our case report highlights a previously undocumented instance of anaphylaxis to Definity® not caused by PEG. We suspect the reaction to be an IgE-mediated response to a non-PEGylated component of Definity®. An alternative explanation for the reaction could be a complement activation-related pseudoallergy. This report provides critical information to physicians on the potential risks of using Definity® and contributes to growing research surrounding the profile of Definity®.
全氟丙烷脂质微球混悬液，商品名为Definity®，是一种微泡超声造影剂。微球包含由磷脂外层脂质壳和聚乙二醇（PEG）化磷脂包裹的八氟丙烷（CF）气体。对全氟丙烷脂质微球的过敏反应非常罕见，仅有一例病例报告明确将该反应归因于PEG辅料。我们报告了一例可能由Definity®的非PEG化成分引起的过敏反应新病例。
我们的患者是一名54岁健康女性，她使用Definity®作为增强剂进行了运动负荷经胸超声心动图检查。注射后15分钟内她发生了过敏反应。在急诊科用苯海拉明和肾上腺素治疗后，症状缓解，随后给予全身性皮质类固醇和昂丹司琼。患者在我们诊所接受了针对Definity®和各种含PEG物质的过敏测试。虽然所有PEG产品测试均为阴性，但她对Definity®进行皮内试验呈阳性。她对PEG 8000皮肤点刺试验也为阴性，并通过了对PEG 3350的口服激发试验，因此排除了PEG作为过敏反应的致病因素。
我们的病例报告突出了一例先前未记录的由非PEG引起的对Definity®的过敏反应。我们怀疑该反应是对Definity®的非PEG化成分的IgE介导反应。该反应的另一种解释可能是补体激活相关的假过敏反应。本报告为医生提供了关于使用Definity®潜在风险的关键信息，并有助于围绕Definity®特性的研究不断增加。
