Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Southwell, United Kingdom.
PLoS One. 2021 Nov 15;16(11):e0257819. doi: 10.1371/journal.pone.0257819. eCollection 2021.
Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments.
To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens.
IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological samples from horses imported to Switzerland from Iceland that subsequently developed IBH or remained healthy. Furthermore, a longitudinal study of 31 IBH horses determined IgE profiles the summer preceding first clinical signs of IBH (TIBH-1), the summer of first clinical signs (TIBH) and the following summer (TIBH+1). In a group of Icelandic horses residing in Sweden, effects of origin (born in Iceland or Sweden) and duration of IBH (<4 years, 4-7 years, >7 years) on Culicoides-specific IgE was evaluated. Sero-positivity rates and IgE levels were compared.
At TIBH, horses were sensitized to a median of 11 r-allergens (range = 0-21), of which nine were major allergens. This was significantly higher than TIBH-1 (3, 0-16), as well as the healthy (1, 0-14) group. There was no significant increase between TIBH and TIBH+1(12, 0-23). IBH-affected horses exported from Iceland had a significantly higher degree of sensitization than those born in Europe, while duration of IBH did not significantly affect degree of sensitization.
Significant sensitization is only detected in serum the year of first clinical signs of IBH. Horses become sensitized simultaneously to multiple Culicoides r-allergens, indicating that IgE-reactivity is due to co-sensitization rather than cross-reactivity between Culicoides allergens. Nine major first sensitizing r-allergens have been identified, which could be used for preventive allergen immunotherapy.
昆虫叮咬超敏反应（IBH）是一种由库蠓属唾液过敏原引起的马的 IgE 介导的过敏性皮炎。由于致病因子不存在，冰岛不会发生 IBH，但出口到库蠓丰富环境的马匹中，IBH 的患病率很高。
利用库蠓重组（r-）过敏原的综合面板，研究对库蠓过敏原的自然致敏过程，并确定从冰岛出口的马匹中的主要致敏过敏原。
对 110 份来自从冰岛进口到瑞士的出现 IBH 或保持健康的马的血清样本进行了 27 种库蠓 r-过敏原的 IgE 微阵列分析。此外，对 31 匹 IBH 马进行了纵向研究，确定了在出现 IBH 临床症状的前一个夏季（TIBH-1）、第一个临床症状的夏季（TIBH）和下一个夏季（TIBH+1）的 IgE 谱。在一组居住在瑞典的冰岛马中，评估了起源（出生于冰岛或瑞典）和 IBH 持续时间（<4 年、4-7 年、>7 年）对库蠓特异性 IgE 的影响。比较了血清阳性率和 IgE 水平。
在 TIBH 时，马对中位数 11 种 r-过敏原（范围=0-21）敏感，其中 9 种为主要过敏原。这显著高于 TIBH-1（3、0-16）和健康组（1、0-14）。TIBH 和 TIBH+1 之间没有显著增加（12、0-23）。从冰岛出口的 IBH 受影响的马比在欧洲出生的马有更高程度的致敏，而 IBH 的持续时间并没有显著影响致敏程度。
只有在出现 IBH 临床症状的那一年，才能在血清中检测到显著的致敏。马同时对多种库蠓 r-过敏原敏感，这表明 IgE 反应是由于共致敏，而不是库蠓过敏原之间的交叉反应。已经确定了 9 种主要的初次致敏 r-过敏原，可用于预防性过敏原免疫治疗。
