Bircher Andreas J, Hofmeier Kathrin Scherer, Link Susanne, Heijnen Ingmar
Allergy Unit, Dermatology Clinic.
Medical Immunology, Laboratory Medicine, University Hospital Basel, Petersgraben 4, CH-4031 Basel, Switzerland.
Eur J Dermatol. 2017 Feb 1;27(1):3-9. doi: 10.1684/ejd.2016.2908.
Until recently, food allergies to mammalian meats have been considered to be very rare. The observation that patients not previously exposed to the monoclonal chimeric antibody cetuximab suffered from severe anaphylaxis upon first exposure, led to the identification of galactose-alpha-1,3-galactose as a new relevant carbohydrate allergen. These patients later often suffered from anaphylactic reactions to red meat. Epidemiological data indicated that bites by the tick Amblyomma americanum in the USA, later also by Ixodes species in other continents, resulted in sensitisation to alpha-gal. On the other hand, in African patients with parasitic disorders, a high prevalence of anti-alpha-gal IgE, without clinical relevance, has been reported. In our four cases, one patient with a late onset of meat allergy had a history of a tick bite. The other three patients had symptoms from childhood or at a juvenile age. This indicates that in some patients, other ways of sensitisation may also take place. However, in patients without atopy, tick bite-induced IgE to alpha-gal may be more relevant. Diagnosis is based on a history of delayed onset of anaphylaxis. Skin tests with commercially available meat test solutions are often equivocal or negative; skin tests with raw meat and particularly pork kidney are more sensitive. Determination of specific IgE to alpha-gal is commercially available. The highest sensitivity is observed with skin and basophil activation tests with cetuximab which is, however, limited by its high costs.
直到最近，对哺乳动物肉类的食物过敏一直被认为非常罕见。未曾接触过单克隆嵌合抗体西妥昔单抗的患者在首次接触时会发生严重过敏反应，这一现象导致半乳糖-α-1,3-半乳糖被确定为一种新的相关碳水化合物过敏原。这些患者后来经常对红肉发生过敏反应。流行病学数据表明，在美国被美洲钝眼蜱叮咬，后来在其他大陆被硬蜱属物种叮咬，会导致对α-半乳糖致敏。另一方面，在患有寄生虫疾病的非洲患者中，已报告有高比例的抗α-半乳糖IgE，但无临床相关性。在我们的4例病例中，1例肉类过敏起病较晚的患者有蜱叮咬史。其他3例患者在儿童期或青少年期就出现了症状。这表明在一些患者中，也可能存在其他致敏途径。然而，在无特应性的患者中，蜱叮咬诱导的针对α-半乳糖的IgE可能更具相关性。诊断基于过敏反应延迟发作的病史。使用市售肉类测试溶液进行皮肤试验往往结果不明确或呈阴性；用生肉尤其是猪肾进行皮肤试验更敏感。针对α-半乳糖的特异性IgE检测在市面上可以买到。使用西妥昔单抗进行皮肤和嗜碱性粒细胞活化试验观察到的敏感性最高，然而，这受到其高成本的限制。
