The pathophysiology of equine asthma (EA) is still not fully described, but the involvement of an allergic reaction is strongly suspected. This theory has led to the use of allergen-specific immunoglobulin (Ig)E tests to support a diagnosis of asthma. The objective of this descriptive study was to evaluate the correlation between four subgroups of EA (mastocytic mild equine asthma [MEA], neutrophilic MEA, mixed MEA, and severe equine asthma [SEA]), allergen specific IgE (measured in both serum and BALF) and mRNA expression of selected genes in bronchoalveolar lavage fluid (BALF). Serum and BALF were collected from 64 horses with a history of lower airway problems with or without poor performance. Differential cell counts from BALF were used to assign horses to one of four groups (mastocytic MEA; neutrophilic MEA, mixed MEA, and SEA). The expression of messenger RNA (mRNA) coding for IL4, IL5, IL8, IL10, TGFB, TNFA, toll-like receptor (TLR)4, IL1RA, IL1B, matrix metalloproteinase 8 (MMP8), TLR9, chemokine ligand 5 (CCL5) and cluster of differentiation (CD)14 in BALF were measured using reverse transcriptase (RT) quantitative PCR (qPCR). Allergen-specific IgE was measured in serum and BALF using an allergen-specific IgE ELISA test with the screening panel: house mites, storage mites, mould and pollen. As expected, the BALF neutrophil differential count correlated with mRNA expression of MMP-8 (r = 0.611, p < 0.001), TLR-4 (r = 0.540, p < 0.001), IL-1RA (r = 0.490, p < 0.001), IL-1β (r = 0.463, p < 0.001) and IL-8 (r = 0.302, p = 0.015). Cytokine expression of IL-1β (p = 0.014), MMP8 (p = 0.028) and IL-1RA (p = 0.037) was significantly higher in the SEA group compared to the MEA subgroups. The BALF mast cell count was correlated with allergen-specific IgE for insects (r = 0.370, p = 0.002) and pollen (r = 0.313, p = 0.011). Eosinophils in BALF were correlated with BALF mRNA expression of IL-4 (r = 0.340, p = 0.006) together with a significant correlation between BALF eosinophils and allergen-specific IgE for mites (r = 0.930, p < 0.001) and pollen in BALF (r = 0.837, p < 0.001). No correlation was found between allergen-specific IgE in serum and BALF for any of the allergen in the screening panel. Based on these results from allergen-specific IgE in horses with EA is not found in systemic circulation, and only the mastocytic and mixed subgroups of horses with EA had allergen-specific IgE in BALF. Further studies are needed to clarify the relationships identified here.

中文翻译：

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马哮喘患者马匹中支气管肺泡灌洗液的细胞因子，细胞学和IgE过敏原。

马哮喘（EA）的病理生理学仍未完全描述，但强烈怀疑涉及过敏反应。该理论导致使用变应原特异性免疫球蛋白（Ig）E测试来支持哮喘的诊断。这项描述性研究的目的是评估EA的四个亚组（肥大性轻度马哮喘[MEA]，嗜中性MEA，混合MEA和重度马哮喘[SEA]），过敏原特异性IgE（在血清和BALF中均测得）之间的相关性）和支气管肺泡灌洗液（BALF）中所选基因的mRNA表达。血清和BALF是从64头有气道问题或无表现的下呼吸道病史的马中收集的。使用来自BALF的差异细胞计数将马分配到四组（肥大膜MEA，嗜中性MEA，混合MEA和SEA）之一。编码IL4，IL5，IL8，IL10，TGFB，TNFA，toll​​样受体（TLR）4，IL1RA，IL1B，基质金属蛋白酶8（MMP8），TLR9，趋化因子配体5（CCL5）的信使RNA（mRNA）的表达使用逆转录酶（RT）定量PCR（qPCR）测量BALF中的CD14和分化簇（CD）14。使用过敏原特异性IgE ELISA测试和以下筛查小组对血清和BALF中的过敏原特异性IgE进行了检测：屋螨，储藏螨，霉菌和花粉。如预期的那样，BALF中性粒细胞差异计数与MMP-8（r = 0.611，p <0.001），TLR-4（r = 0.540，p <0.001），IL-1RA（r = 0.490，p <0.001）的mRNA表达相关），IL-1β（r = 0.463，p <0.001）和IL-8（r = 0.302，p = 0.015）。IL-1β（p = 0.014），MMP8（p = 0.028）和IL-1RA（p = 0）的细胞因子表达。与MEA亚组相比，SEA组的037）显着更高。BALF肥大细胞计数与昆虫（r = 0.370，p = 0.002）和花粉（r = 0.313，p = 0.011）的过敏原特异性IgE相关。BALF中的嗜酸性粒细胞与IL-4的BALF mRNA表达相关（r = 0.340，p = 0.006），并且BALF嗜酸性粒细胞与螨的过敏原特异性IgE之间显着相关（r = 0.930，p <0.001）和BALF中的花粉（r = 0.837，p <0.001）。在筛查小组中，对于任何过敏原，血清中的过敏原特异性IgE与BALF之间均未发现相关性。基于这些结果，在体循环中未发现具有EA的马的过敏原特异性IgE，只有具有EA的马的肥大细胞和混合亚组在BALF中具有过敏原特异性IgE。