Background

Alpha-gal syndrome is a hypersensitivity reaction to red meat mediated by IgE antibody specific to galactose-α-1,3-galactose carbohydrate (alpha-gal). Amblyomma tick bites are associated with this condition, but the pathophysiology is not understood.

Objective

To clarify the mechanism of development of alpha-gal syndrome after tick bites.

Methods

We compared alpha-gal antibody levels between patients with and without a history of tick bites and examined histologic stainings of tick bite lesions between patients with and without detectable alpha-gal IgE antibody.

Results

Patients who had ≥2 tick bites had higher levels of alpha-gal IgE antibody compared with those with only 1 tick bite or healthy individuals. On histologic investigation, greater numbers of basophils and eosinophils, but not mast cells, were observed infiltrating lesions of patients with ≥2 tick bites compared with those with 1 tick bite. Type 2 cytokine-producing T-cell infiltration was predominantly observed in such patients.

Limitations

The study was conducted at a single institution in Japan.

Conclusion

In Amblyomma tick bite lesions, basophils; eosinophils; and type 2, cytokine-producing T cells infiltrate the skin and alpha-gal IgE antibodies are produced. These findings provide a potential mechanistic connection between Amblyomma bites and red meat hypersensitivity.

中文翻译：

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反复的 Amblyomma testudinarium 蜱叮咬与半乳糖-α-1,3-半乳糖碳水化合物 IgE 抗体水平升高有关：在单一机构进行的回顾性队列研究

背景

α-gal 综合征是由对半乳糖-α-1,3-半乳糖碳水化合物 (α-gal) 特异的 IgE 抗体介导的对红肉的超敏反应。Amblyomma蜱叮咬与这种情况有关，但其病理生理学尚不清楚。

客观的

阐明蜱叮咬后发生α-gal综合征的机制。

方法

我们比较了有和没有蜱叮咬史的患者之间的 α-gal 抗体水平，并检查了有和没有可检测到 α-gal IgE 抗体的患者之间蜱叮咬病变的组织学染色。

结果

与仅有 1 次蜱叮咬或健康个体相比，被蜱叮咬 ≥2 次的患者的 α-gal IgE 抗体水平更高。在组织学研究中，与被蜱叮咬 1 次的患者相比，被蜱叮咬 ≥2 次的患者的病灶中观察到更多的嗜碱性粒细胞和嗜酸性粒细胞，而不是肥大细胞。在此类患者中主要观察到产生 2 型细胞因子的 T 细胞浸润。

限制

该研究是在日本的一个机构中进行的。

结论

在Amblyomma蜱叮咬病变中，嗜碱性粒细胞；嗜酸性粒细胞；和 2 型，产生细胞因子的 T 细胞浸润皮肤并产生 α-gal IgE 抗体。这些发现提供了Amblyomm a 叮咬和红肉超敏反应之间的潜在机制联系。