兽研致编辑
我们饶有兴趣地阅读了Colosimo等人[1]关于减少猫过敏原Fel d 1暴露及由此引发的过敏性致敏的创新策略的文章。
该文非常完整，我们对其内容没有异议。然而，我们希望提出一条额外的、普遍存在的暴露途径，即猫过敏原在无动物环境中的被动传播，尤其是缺乏针对这一关键方面的预防措施的信息。
这一澄清很重要，因为文中报道的大多数创新策略仅适用于患者所拥有的单只猫，或该动物居住的室内环境。显然，患者仍会暴露于他们可能遇到的其他猫的过敏原/环境。相反，针对被动传播的针对性预防措施具有普遍性，因为它们应能减少猫过敏原的“无处不在”现象，从而降低无动物接触条件下的致敏风险。
猫（和犬）过敏原应被视为无处不在，因为它们不仅存在于饲养这些动物的室内环境中，还存在于从未饲养过这些动物的其他私人或公共室内场所。公共空间包括托儿所、办公室、医院、酒店、学校和公共交通工具。这些被猫过敏原污染的室内环境能够在易感个体中诱导过敏性致敏，并在已高度致敏的受试者中触发呼吸道症状。事实上，在这些受污染的环境中，猫过敏原的量高于临床显著阈值。即，通常认为每克灰尘中1 μg和8–10 μg的过敏原分别足以诱导致敏或触发呼吸道症状。显然，这些阈值必须被视为临床研究中受试人群的“平均值”。然而，在临床实践中，有必要考虑由遗传和环境因素导致的个体对宠物过敏原暴露的广泛易感性，因为这些变量能够影响症状的轻重程度。
在发达国家，猫过敏原的无处不在导致气道受到持续刺激，类似于屋尘螨所诱导的刺激。
猫过敏原在无动物室内环境中的积累与养猫访客的数量或经常接触这些动物的人数相关。我们已经证明，衣物[2]以及人类头发[3]构成了将猫过敏原转移到无宠物室内环境中的途径（图1）。
[图：猫/狗过敏原在室内私人与公共环境中的动态变化及从污染物中去除猫过敏原的可能方法]
我们此前已在一种较少见的宠物（兔）中证明了这一点[5]。然而，较少的证据表明其他动物（如马[6, 7]、啮齿动物[8]和牛[9]）的过敏原也可能存在被动传播。对于后几类动物，被动传播最常见的原因是职业性的。事实上，饲养员、农民、动物处理人员和其他专业人员可以通过衣物或其他物品将这些动物的过敏原从工作场所带到家中。
因此，我们认为有必要提及不同清洁方法在去除被动污染的羊毛织物中猫过敏原方面的有效性。我们此前已证明，用水洗涤这些织物（效果极佳）[6, 7, 8, 9, 10]优于干洗（效果良好）[7, 8, 9, 10, 11]和吸尘（效果差）[8, 9, 10, 11, 12]（图1）。
穿着携带最少猫/犬过敏原的衣物对于避免其在医院、诊所、托儿所等场所的室内积累至关重要。一个例子是犬和训导员进入儿科医院病房进行宠物治疗。在瑞典，进入认证要求入院前对医院犬进行清洗。我们建议在这些指南中纳入关于医院犬主人/训导员衣物的一些预防措施[13]。
作为优先事项，我们建议更换私人衣物，使用医院服装和一次性发帽。或者，在衣物外穿一次性罩衣可能有用，同时始终用一次性帽子遮盖头部。我们建议即使是与宠物有持续/直接接触的普通访客也使用这些材料[9, 10, 11, 12, 13]。
总之，我们认为防止猫过敏原的被动扩散是减少室内污染及由此引发的过敏性致敏的重要措施。未来还应针对这一主题规划进一步的“创新性”研究，例如评估将蛋白酶（如Subtilisin A）应用于患者衣物的有效性，这可能比反复洗涤更为简便。遗憾的是，这些方法仍处于初步实验室阶段，需要进一步研究以确认其在真实条件下的有效性，尤其是尽量减少对气道和皮肤可能的不良反应。
作者贡献
Gennaro Liccardi：概念构思、初稿撰写、监督。Matteo Martini：审阅与编辑、监督。Maria Beatrice Bilò：审阅与编辑。Lorenzo Cecchi：审阅与编辑。Manlio Milanese：审阅与编辑。Roberta Maniscalco：审阅与编辑。Paola Rogliani：审阅与编辑。
基金
作者无需报告任何内容。
利益冲突
作者声明无利益冲突。
一目了然
在无宠物环境中防止宠物（猫/狗）过敏原的被动传播，似乎是降低易感人群对宠物过敏致敏程度的不可或缺的措施。
查看英文原文▾
To the Editor
We read with interest the article of Colosimo et al. [1] concerning innovative strategies to reduce exposure and consequent allergic sensitization to cat allergen Fel d 1.
The article is very complete, and we have no objections to its contents. However, we wish to address an additional and universal exposure pathway that is the passive transport of cat allergens in animal‐free environments and, above all, the lack of information on preventive measures to this crucial aspect.
This clarification is important because the majority of the innovative strategies reported in the text are applicable just to the single cat that is owned by the patient, or to the indoor environment where the animal lives. Obviously, patients remain exposed to the allergens/environments of other cats that they may encounter. On the contrary, targeted prevention measures against passive transport have a universal character as they should reduce the phenomenon of the “ubiquity” of the cat allergen and therefore the risk of sensitization without contact with animals.
Cat (and dog) allergens should be considered as ubiquitous because they are found not only in indoor environments where these animals are kept, but also in other indoor private or public places where they have never been kept. Public spaces include nurseries, offices, hospitals, hotels, schools and means of public transport. These indoor environments, contaminated by cat allergens, are able to induce allergic sensitization in susceptible individuals and trigger respiratory symptoms in already highly sensitized subjects. In fact, in these contaminated environments, the amount of cat allergens is higher than clinically significant thresholds. Namely, 1 and 8–10 μg of allergen/g are generally recognized as sufficient to induce sensitization or trigger respiratory symptoms for dust, respectively. Obviously, these thresholds must be considered as “averages” over the population examined in clinical studies. However, in clinical practice, it is necessary to account the wide individual susceptibility to pet allergen exposure resulting from genetic and environmental factors, as these variables are able of influencing the onset of more or less severe symptoms.
In developed countries, the cat allergen ubiquity causes a persistent stimulation of airways like that induced by dust mite.
Accumulation of cat allergens in indoor environments without animals is correlated with the number of visitors owning a cat or with those who are in regular contact with these animals. We have shown that clothing [2], but also human hair [3], constitute a means of transferring cat allergens into pet‐free indoor environments (Figure 1).
[图：Dynamics of cat/dog allergens in indoor private/public environments and possible means to remove cat allergens from cont]
We have previously demonstrated it in a less common pet (rabbit) [5]. However, a smaller body of evidence suggests the possibility of passive transport of allergens also in other animals such as horses [6, 7], rodents [8] and cattle [9]. For these latter animals, the most common cause of passive transport is occupational. Indeed, breeders, farmers, animal handlers, and other professionals can transfer these animals' allergens from their workplaces to their homes, presumably through clothing or other items.
Therefore, we believe it is important to mention the validity of different cleaning methods in removing cat allergens from passively contaminated wool fabrics. We have previously demonstrated the efficacy of washing these fabrics in water (excellent) [6, 7, 8, 9, 10] compared to dry cleaning (good) [7, 8, 9, 10, 11] and vacuuming (poor) [8, 9, 10, 11, 12] (Figure 1).
The need to wear clothes that carry minimal amounts of cat/dog allergens becomes crucial to avoid their indoor accumulation in some places such as hospitals, clinics, nurseries, etc. An example could be the entry of dogs and trainers into pediatric hospital departments for pet therapy. In Sweden, for entry certification, washing the hospital dog before entering is required. We proposed including in these Guidelines some precautions regarding the clothing of hospital dog owners/trainers [13].
As a priority, we suggested changing private clothes and using hospital clothing and a disposable cap for hair. Alternatively, it may be useful to wear disposable gowns over clothes, always with head covered by a disposable cap. We suggest the use of these materials even by ordinary visitors who have constant/direct contact with pets [9, 10, 11, 12, 13].
In conclusion, we believe that preventing the passive spread of cat allergens is an important measure to try to reduce indoor contamination and consequent allergic sensitization. Further “innovative” studies should be planned also on this topic in the future, such as evaluating the effectiveness of proteolytic enzymes (e.g. Subtilisin A) applied to patients' clothes, that could be easier than repeated washing. Unfortunately, these procedures are still in the preliminary laboratory stage, and further studies are needed to confirm their effectiveness in real‐world conditions and, above all, to minimize possible adverse effects on airways and skin.
Author Contributions
Gennaro Liccardi: conceptualization, writing – original draft, supervision. Matteo Martini: writing – review and editing, supervision. Maria Beatrice Bilò: writing – review and editing. Lorenzo Cecchi: writing – review and editing. Manlio Milanese: writing – review and editing. Roberta Maniscalco: writing – review and editing. Paola Rogliani: writing – review and editing.
Funding
The authors have nothing to report.
Conflicts of Interest
The authors declare no conflicts of interest.
Summary at a Glance
The prevention of passive transport of pet (cat/dog) allergens in pet‐free environments appears to be an indispensable measure to reduce the degree of allergic sensitization to pets in susceptible population.