兽研引言
过敏性疾病常见于人类和伴侣动物，但关于共同家庭环境如何影响跨物种过敏原识别，目前知之甚少。蟑螂过敏原是人类过敏性疾病的主要诱因，但其对同居犬的免疫学影响尚未得到系统评估。我们采用基于“同一健康”理念的比较方法，研究了68对居住在共同家庭环境中的人–犬配对中蟑螂IgE识别谱。
方法
我们通过结构化问卷评估了家庭特征、过敏史和蟑螂侵扰模式。采用免疫印迹法分析配对主人–犬样本中对美洲大蠊过敏原的血清IgE反应性。
结果
52.9%的主人–犬配对中存在并发过敏性疾病。蟑螂活动最常报告于厨房（61.4%），另有证据显示犬进食碗附近（10.0%）和睡眠区域（4.3%）也存在蟑螂活动，表明存在共同环境暴露。比较免疫印迹分析揭示了共享性和物种特异性IgE识别模式。Per a 1、Per a 3、Per a 4和Per a 9在两个物种中均被识别，其中犬对Per a 4（69%）和Per a 9（40%）的识别频率较高，而主人对Per a 1（34%）、Per a 3（34%）和Per a 7（26%）的识别频率较高。
讨论
这些发现表明，共同家庭暴露不一定产生相同的过敏原识别谱，并支持在共同环境条件下存在物种特异性过敏原识别的概念。本研究为人类与伴侣犬的比较过敏学研究提供了新见解，并强调了在研究环境过敏性疾病的应考虑宿主生物学和家庭暴露两方面因素的重要性。
[内容请查看原文]
引言
家庭环境已成为人类和伴侣动物同时暴露于共同环境因素的共享微生态系统。这一概念与“同一健康”框架相一致，该框架认为人类、动物及其共享环境的健康密切关联（1–4）。随着全球宠物饲养持续增加，人们越来越关注了解共享室内环境如何促进跨物种过敏性疾病的发生（3, 5–7）。识别共同的环境风险因素可能增进我们对过敏发病机制的理解，同时为人类和伴侣动物的疾病预防策略提供依据。
在室内环境过敏原中，蟑螂来源的过敏原，特别是美洲大蠊（Periplaneta americana）来源的过敏原，是公认的人类过敏性鼻炎、哮喘和特应性皮炎的触发因素（8–12）。组分解析诊断的进展已鉴定出十种主要过敏原分子（Per a 1–Per a 10），使得能够详细表征过敏原特异性IgE反应并提高过敏诊断的精确性（8, 10, 13）。尽管蟑螂过敏原在人类过敏性疾病中的作用已被广泛研究，但对其在暴露于相同室内环境的伴侣动物中致敏作用的了解却少得多。
家犬经常发生自然发生的过敏性疾病，尤其是犬特应性皮炎，其与人类特应性疾病具有许多临床、免疫学和病理学特征，包括IgE介导的环境过敏原致敏（14, 15）。由于犬与主人居住在同一室内环境，同时表现出不同的行为模式，如增加与地板表面、家庭灰尘以及进食和休息区域周围有机碎屑的接触，因此尽管生活在同一家庭中，它们可能经历不同的过敏原暴露谱。因此，犬已被提议作为室内环境质量的生物哨兵，并代表在“同一健康”框架下研究环境过敏原暴露的有价值的比较模型（6, 16）。然而，共同家庭暴露是否导致对单个蟑螂过敏原组分的相似或物种特异性识别仍不清楚。迄今为止，尚无研究系统比较同居人类及其宠物犬对美洲大蠊过敏原的分子IgE识别谱。
为填补这一知识空白，我们开展了一项涉及68对居住在同一家庭的主人–犬配对的“同一健康”研究。使用结构化环境问卷评估家庭蟑螂暴露，并通过免疫印迹法分析对美洲大蠊过敏原的血清IgE反应性。我们旨在确定蟑螂过敏原特异性IgE识别的频率，比较人类与犬之间的分子识别谱，并评估家庭环境暴露与过敏原特异性IgE反应之间的关系。本研究为跨物种过敏原识别模式提供了新见解，并强调了整合人类和兽医学视角以更好地理解过敏性疾病环境决定因素的价值。
[内容请查看原文]
材料与方法
[内容请查看原文]
伦理批准
研究方案经台中荣民总医院机构审查委员会批准（IRB TCVGH 编号：CE23070A-1/-2），研究各方面均符合1975年《赫尔辛基宣言》的伦理准则。所有人类参与者在入组前均提供书面知情同意。宠物犬无需伦理批准，因为持证兽医在常规临床操作中采集血液。
[内容请查看原文]
研究参与者与招募
参与者于2024年9月至2025年7月期间在台湾台中荣民总医院门诊大厅招募。连续接触来院就医的犬主人，若其拥有至少一只居住于同一家庭的宠物犬，则邀请其参与。招募由受过培训的研究人员通过面对面筛查进行。同意参与的合格参与者完成问卷并提供血液样本。其宠物犬随后在合作兽医诊所进行血液采集。每对入组的 owner–dog 配对代表一个共享家庭环境，用于后续分析。
[内容请查看原文]
研究设计与基于问卷的环境评估
共纳入68对人–犬配对，居住于共享家庭环境，以研究过敏原特异性IgE反应模式。为表征家庭环境与暴露水平，犬主人完成了一份结构化问卷，旨在采集人口学特征、过敏史、环境暴露及与家庭过敏原分布相关的宠物相关因素。调查评估了：(1) 两个物种的人口学特征；(2) 过敏临床病史（如皮炎、呼吸道症状）；以及(3) 家中观察到的蟑螂活动。特别关注犬与蟑螂可能发生互动的“环境界面”，如厨房区域、食盆和宠物睡眠区。
[内容请查看原文]
美洲大蠊提取物及大肠杆菌表达重组蛋白的制备
美洲大蠊粗提物（CraA）按先前所述方法制备（8）。这些提取物作为代表性环境过敏原来源，反映家庭蟑螂暴露。
除 Per a 8 外，重组 Per a 1-10 蛋白均在本实验室使用大肠杆菌表达系统生产。细菌表达后，重组蛋白按我们先前建立的方案（8, 10）使用 Novagen（德国达姆施塔特）提供的试剂通过亲和色谱纯化。Per a 8 被排除，因其在 CraA 中检出频率低；因此，本分析纳入九种重组 Per a 过敏原。
[内容请查看原文]
IgE免疫印迹与组分解析分析
通过免疫印迹评估对蟑螂提取物的过敏原特异性IgE反应性，以实现跨物种比较分析。CraA 蛋白经 SDS–PAGE（4%浓缩胶，12%分离胶）分离并转移至硝酸纤维素膜。膜用含2%牛血清白蛋白的PBST封闭，并与犬主人或犬的个体血清（1:5稀释）于4 °C孵育过夜。使用小鼠抗人IgE碱性磷酸酶偶联抗体或小鼠抗犬IgE辣根过氧化物酶偶联抗体进行物种特异性检测。洗涤后，免疫反应条带使用增强化学发光（Millipore，美国马萨诸塞州）显影，并用高分辨率凝胶成像系统（G:Box Chemi-XX9，SYNGENE）记录。
先前表征的抗九种选定 Per a 过敏原（Per a 1–7 和 Per a 9–10）的多克隆抗体被用作参考图谱，以协助识别 CraA 中相应的过敏原条带（8）。Per a 8 因其丰度低且在 CraA 中检出频率低而被排除；因此，使用了九种过敏原特异性抗体。对每种抗体分析两个泳道：左侧泳道含相应纯化重组 Per a 过敏原作为阳性参考，右侧泳道含 CraA，从而可识别相应天然过敏原组分的迁移位置。这些参考图谱随后用于协助在血清IgE免疫印迹中指定推定的 Per a 过敏原条带。
由于从宠物犬伦理上可采集的血清体积有限，现有犬样本优先用于定性免疫印迹分析。因此，全面的免疫印迹抑制试验、犬过敏原特异性IgE定量测定以及所有过敏原组分的验证均不可行。据此，本研究侧重于比较配对人血清与犬血清之间的IgE识别模式，而非犬过敏原特异性IgE反应的定量评估。据此，本研究侧重于比较IgE识别，而非犬过敏原库的全面表征。
[内容请查看原文]
统计分析
统计分析使用SPSS Statistics 22版进行。过敏患病率以百分比表示。采用卡方检验评估主人及其犬只过敏状态之间的关联，以反映共同的家庭暴露。应用逻辑回归分析评估环境因素与跨物种过敏患病率之间的关系。p值<0.05被认为具有统计学意义。
[内容请查看原文]
结果
[内容请查看原文]
人-犬配对的家居特征
本研究共纳入68对共享同一家庭环境的主人-犬配对。主人及其宠物的人口学和过敏相关特征总结于表1。在主人中，平均年龄为34.10±10.84岁，以女性参与者为主（79.41%）。82.35%的主人报告有过敏性疾病史。值得注意的是，16.18%的主人在家中引入宠物犬后自报过敏症状加重，提示在共享室内环境中养宠与过敏性疾病表现之间可能存在感知到的相互作用。在宠物犬中，66.18%被主人报告曾出现过敏症状。
Table 1. Demographic and allergy characteristics of dog owners and their pets ( N = 68).
| Characteristic | Owners ( n = 68) | Dogs ( n = 68) |
|---|---|---|
| Mean age, years (±SD) | 34.10 (±10.84) | 5.54 (±3.81) |
| Sex, %, male/female | 20.59/79.41 | 45.59/54.41 |
| Residential duration, years (±SD) | 8.83 (±10.64) | – |
| History of allergy, % | 82.35 | 66.18 |
| Self-reported worsening of allergy after dog ownership, % | 16.18 | – |
在家庭层面检查过敏状态时，超过半数的配对（52.94%，36/68）表现出主人和犬同时存在过敏状况（表2）。这种高共现率提示共享家庭环境暴露可能对多物种家庭的过敏健康产生影响。仅主人报告过敏的配对占29.41%，而犬过敏但主人不过敏的配对占13.23%。仅4.41%的家庭报告两个物种均无过敏症状。这些发现表明共享家庭环境中过敏表现存在高度重叠。
Table 2. Distribution of sample numbers in the owner–dog allergy matrix by owner self-assessment ( N = 68).
| Allergic disease status in dogs | Owner without self-reported allergy | Owner with self-reported allergy |
|---|---|---|
| Dog without allergic disease | N = 3 (4.41%) | N = 20 (29.41%) |
| Dog with allergic disease | N = 9 (13.23%) | N = 36 (52.94%) |
[内容请查看原文]
家庭蟑螂暴露的环境证据
基于问卷的评估显示，参与的人-犬配对中家庭蟑螂暴露广泛存在（表3）。蟑螂活动最常报告于厨房（61.43%），其次是客厅（30.43%）、卧室（18.84%）和浴室（11.59%）。除一般家庭区域外，犬相关微环境中也报告了蟑螂活动的证据，包括食碗附近区域（10.00%）和犬睡眠区域（4.29%），表明同一家庭环境中人和伴侣动物可能存在共享暴露途径。
Table 3. Household cockroach exposure characteristics in human–dog shared environments ( N = 68).
| Characteristic | n (%) |
|---|---|
| Section A. Household pest management and dog-related factors | |
| Cockroach bait placed in household | 42.86 |
| Dog observed catching cockroaches | 31.88 |
| Increased cockroach sightings after dog ownership | 8.57 |
| Section B. Locations of cockroach infestation within households | |
| Kitchen | 61.43 |
| Living room | 30.43 |
| Bedroom | 18.84 |
| Bathroom | 11.59 |
| Section C. Evidence of cockroach activity in dog-associated areas | |
| Near dog feeding bowls | 10.00 |
| Near dog sleeping areas | 4.29 |
关于家庭害虫管理和动物相关因素，42.86%的主人报告在家中放置了蟑螂饵剂，而31.88%观察到其犬捕捉蟑螂。在主人中，8.57%报告养犬后蟑螂目击更频繁。这一观察可能反映与养宠相关的家庭环境条件变化，包括喂食区域周围宠物食物残渣和其他有机物质的可用性。当喂食区域和食物残渣未得到充分清洁时，这些条件可能为蟑螂提供额外的食物资源，并可能增加其活动或可见度。然而，由于本研究未对蟑螂侵扰进行客观量化，该关联不应被解释为养犬直接导致或增加蟑螂侵扰的证据。
综上所述，问卷数据表明人和犬的过敏症状经常在同一家庭中共现，并与共享环境蟑螂侵扰暴露相关。
[内容请查看原文]
对蟑螂过敏原的IgE识别谱比较
为表征分子IgE识别模式，本研究检测了业主及其宠物犬血清中对美洲大蠊粗提物（CraA）的过敏原特异性IgE反应性。补充图S1展示了56对业主-犬配对样本的代表性免疫印迹图谱。如图1A所示，首先使用针对Per a 1–10的多克隆抗体（Per a 8除外）鉴定CraA中相应过敏原的位置。基于这些参考位置，随后分析业主及其犬的血清样本以建立其IgE结合谱，代表性结果分别见图1B、C。
[图：人业主与其宠物犬对美洲大蠊粗过敏原提取物（CraA）的IgE识别比较。（]
免疫印迹分析鉴定出若干由配对人与犬血清共同识别的主要IgE反应性蟑螂过敏原组分。各蟑螂过敏原组分IgE识别的频率总结于图2。在业主中，最常被识别的过敏原为Per a 1（34%）和Per a 3（34%），其次为Per a 7（26%）和Per a 4（18%）。同时也检测到针对Per a 2（9%）和Per a 9（9%）的IgE反应性，而未观察到针对Per a 5、Per a 6或Per a 10的可检测IgE反应性。相比之下，宠物犬对Per a 4（69%）、Per a 1（63%）和Per a 9（40%）的IgE识别频率显著更高。犬对Per a 3（9%）和Per a 10（6%）的反应性相对较低。两个物种中均观察到对Per a 5和Per a 6的IgE结合极少或无结合。
[图：选定美洲大蠊过敏原组分IgE识别的患病率。柱状图展示了……的百分比]
综上所述，这些发现表明业主与犬之间主要重叠的IgE识别过敏原为Per a 1、Per a 3、Per a 4和Per a 9。值得注意的是，犬对Per a 4、Per a 1和Per a 9的IgE识别频率更高，而业主对Per a 3和Per a 7的IgE反应性识别频率更高，突显了两个物种之间既有共享又有差异的IgE识别模式。
[内容请查看原文]
讨论
本研究对共同居住的人-犬配对中蟑螂过敏原识别进行了比较分析。通过整合比较性IgE免疫印迹分析与家庭环境调查数据，我们证明尽管业主与其宠物犬经常共享过敏性疾病，但它们表现出不同的过敏原识别谱。据我们所知，这是首项表征居住于同一家庭中配对人与伴侣犬对美国蟑螂过敏原物种特异性IgE识别模式的研究。
[内容请查看原文]
共享家庭作为同一健康微生态系统
我们的发现强调了家庭作为共享微生态系统的概念，其中人与动物承受相同的环境应激源。配对中并发过敏性疾病的比率较高（52.92%），提示蟑螂侵扰不仅是人类健康问题，而且是影响所有哺乳动物居住者的普遍环境危害。厨房被确定为美洲大蠊的主要储库（61.43%），但在食盆附近（10%）和睡眠区域（4.29%）发现蟑螂活动，揭示了犬的特定暴露途径。我们的结果与既往研究一致，表明家庭蟑螂暴露与蟑螂过敏原特异性IgE识别的可能性呈正相关（5, 17）。这些行为可能增加犬反复接触可能被蟑螂过敏原污染的家庭灰尘和表面的机会。
由于无法可靠地量化环境过敏原浓度，本研究中的家庭蟑螂暴露采用标准化问卷进行评估，描述侵扰地点和业主报告的蟑螂活动证据。这些指标代表环境暴露的替代指标，而非直接过敏原定量。
[内容请查看原文]
物种特异性分子特征：犬中的Per a 4和Per a 9
本研究的一项关键发现是物种间对过敏原Per a 1–10的IgE识别谱差异。虽然Per a 1和Per a 3是两个物种的共同抗原，但宠物犬对Per a 4（69%）和Per a 9（40%）的IgE反应性患病率显著更高。相比之下，业主对Per a 3和Per a 7的IgE识别频率更高。这些差异可能源于多种生物学过程，包括物种特异性暴露行为、上皮屏障功能、抗原摄取和免疫加工（18, 19）。
Per a 4（一种脂质运载蛋白样蛋白）和Per a 9（精氨酸激酶）在犬中占主导地位的识别可能反映的是暴露行为的差异，而非家庭过敏原来源的差异。犬通过嗅闻、舔舐、休息和进食行为长时间与地板表面密切接触，增加了其反复暴露于家庭灰尘和蟑螂相关微环境的机会（20–22）。支持这一观察的是，来自报告喂食碗附近有蟑螂活动的家庭的犬，其对Per a 4和Per a 9的IgE识别频率更高。尽管本研究未直接测量环境过敏原浓度，但这些发现表明，共同的家庭暴露并不一定导致相同的过敏原识别谱。相反，物种特异性的行为暴露，连同抗原加工和免疫反应的差异，可能促成了在人与犬之间观察到的不同IgE识别模式（23, 24）。
[内容请查看原文]
人与犬之间过敏原暴露和IgE识别途径的潜在差异
尽管人与犬共享相同的家庭环境，但其过敏原特异性IgE识别谱存在显著差异，提示单纯的环境暴露不能完全解释两个物种之间观察到的物种特异性IgE反应。相反，过敏原暴露途径、宿主生物学特征和行为模式的差异可能促成不同的过敏原识别。
一种可能的解释是过敏原主要暴露途径的差异。在人类中，吸入通常被认为是室内气传过敏原（包括蟑螂过敏原）的重要暴露途径，对上呼吸道和下呼吸道产生影响。相比之下，伴侣犬通过行走、躺卧、嗅闻和梳理频繁接触地板表面，导致皮肤和口腔黏膜频繁接触可能含有过敏原的环境物质。实验研究表明，经皮过敏原暴露可诱导过敏原特异性IgE反应并促进过敏性炎症，尤其是当上皮屏障完整性受损时（9, 12）。
上皮屏障的物种特异性特征可能进一步影响过敏原摄取和随后的IgE识别。犬特应性皮炎与皮肤屏障功能受损、脂质组成改变和经表皮水分丢失增加相关，这些变化可能促进过敏原渗透和免疫激活（25）。类似机制在人类特应性皮炎中已有描述，尽管呼吸道暴露和皮肤暴露的相对贡献可能因物种而异（15）。因此，暴露于相同的家庭过敏原来源可能导致抗原摄取、加工和IgE识别的差异。
此外，先天免疫反应、抗原呈递和行为暴露的差异可能进一步塑造过敏原识别谱。这些因素可能促成了在犬中观察到的对Per a 4和Per a 9更高的IgE识别频率，而主人则表现出对Per a 3和Per a 7更高的IgE识别。然而，由于本研究未直接评估过敏原暴露途径、上皮屏障功能、抗原呈递或IgE产生，这些机制应被视为假设而非实验证明的途径。未来整合标准化环境过敏原定量、上皮屏障生物标志物以及人–犬配对纵向监测的研究，将有助于阐明物种之间观察到的不同IgE识别模式背后的生物学机制。
[内容请查看原文]
犬作为家庭过敏原暴露的生物学哨兵
从比较过敏学的角度来看，我们的发现提示宠物犬可作为家庭过敏原暴露的生物学哨兵。犬长时间与地板表面、家庭灰尘和宠物相关微环境密切接触，导致其环境过敏原的累积暴露量高于主人。因此，犬IgE识别谱的改变可能在人类出现类似临床明显模式之前反映家庭过敏原负荷的变化（12, 26）。尽管需要额外的纵向研究，但我们的发现支持以下假设：伴侣犬可作为监测家庭过敏原暴露的实用生物学哨兵，并可能补充传统的环境评估。
[内容请查看原文]
对综合害虫与过敏原管理的启示
本研究结果可能对公共卫生和兽医实践具有启示意义。标准害虫控制措施通常侧重于可见的以人为中心的区域。然而，我们的研究强调需要“综合害虫管理”，特别针对宠物相关界面，如定期清洁喂食点和睡眠区域。减少这些热点区域的蟑螂侵扰不仅对管理犬特应性皮炎至关重要，而且对于减轻共享家庭环境中的累积过敏原负荷也必不可少，从而保护整个配对的健康。
[内容请查看原文]
局限性与未来方向
一项局限性涉及在伦理和临床考量下可采集的犬血清体积有限。因此，分析优先用于比较免疫印迹，而全面的犬过敏原特异性IgE定量、免疫印迹抑制试验以及额外过敏原组分的评估均不可行。因此，本研究表征的是比较性IgE识别模式，而非提供过敏原交叉反应性或犬蟑螂过敏原特异性IgE识别全谱的直接证据。
另一项局限性是环境蟑螂过敏原浓度未纳入最终分析。家庭灰尘样本由犬主人采集，而非由经过培训的研究人员使用标准化采样方案采集。因此，采样位置、表面积、采集方法以及所获灰尘数量和质量方面的显著变异性限制了定量ELISA测量的可比性和可靠性。在评估现有标本和检测性能后，这些测量被认为可靠性不足以纳入分析。因此，家庭问卷数据应被解读为对报告蟑螂暴露的评估，而非环境过敏原负荷的定量测量。未来研究应采用标准化、前瞻性监督的灰尘采集和经验证的定量过敏原检测，以直接将环境过敏原水平与人-犬配对中组分特异性IgE识别相关联。
尽管对九种选定过敏原的分析无法完全捕捉美洲大蠊的分子IgE识别谱——目前WHO/IUIS过敏原命名数据库（http://www.allergen.org）中已注册该物种的23种过敏原——但足以实现本研究的主要比较目标。具体而言，我们的研究结果表明，共享同一家庭环境的人和犬表现出不同的过敏原特异性IgE识别模式。
综上所述，这些发现表明，人-犬配对研究为理解环境过敏原特异性IgE识别提供了有用的转化模型，并可能促进兽医和人类过敏研究领域的未来比较研究。此类研究可能有助于区分暴露途径的差异与物种固有的免疫应答差异。
[内容请查看原文]
结论
总之，尽管生活在同一家庭环境中，人类及其同居的宠物犬对美国蟑螂过敏原表现出共享的和物种特异性的IgE识别。这些发现为比较过敏学提供了新见解，并支持使用人-犬配对研究来调查家庭过敏原暴露和过敏性疾病。
查看英文原文▾
Introduction
Allergic diseases commonly affect both humans and companion animals, yet little is known about how shared household environments influence allergen recognition across species. Cockroach allergens are major contributors to human allergic disease, yet their immunological impact on cohabiting dogs has not been systematically evaluated. Using a One Health–informed comparative approach, we investigated cockroach IgE recognition profiles in 68 human–dog dyads residing in shared domestic environments.
Methods
We assessed household characteristics, allergic histories, and cockroach infestation patterns through structured questionnaires. Serum IgE reactivity to Periplaneta americana allergens was analyzed by immunoblotting in paired owner–dog samples.
Results
Concurrent allergic conditions were identified in 52.9% of owner–dog pairs. Cockroach activity was most frequently reported in kitchens (61.4%), with additional evidence near dog feeding bowls (10.0%) and sleeping areas (4.3%), indicating common environmental exposure. Comparative immunoblot analysis revealed both shared and species-specific IgE recognition patterns. Per a 1, Per a 3, Per a 4, and Per a 9 were recognized in both species, whereas dogs showed higher recognition frequencies for Per a 4 (69%) and Per a 9 (40%), while owners more frequently recognized Per a 1 (34%), Per a 3 (34%) and Per a 7 (26%).
Discussion
These findings suggest that shared household exposure does not necessarily produce identical allergen recognition profiles and support the concept of species-specific allergen recognition under common environmental conditions. This study provides new insights into comparative allergy between humans and companion dogs and highlights the importance of considering both host biology and household exposure when investigating environmental allergic diseases.
[内容请查看原文]
Introduction
The domestic environment has become a shared micro-ecosystem in which humans and companion animals are simultaneously exposed to common environmental factors. This concept aligns with the One Health framework, which recognizes that the health of humans, animals, and their shared environment is closely interconnected (1–4). As pet ownership continues to increase worldwide, there is growing interest in understanding how shared indoor environments contribute to the development of allergic diseases across species (3, 5–7). Identifying common environmental risk factors may improve our understanding of allergy pathogenesis while informing strategies for disease prevention in both humans and companion animals.
Among indoor environmental allergens, cockroach-derived allergens, particularly those from Periplaneta americana (the American cockroach), are well-established triggers of allergic rhinitis, asthma, and atopic dermatitis in humans (8–12). Advances in component-resolved diagnostics have identified ten major allergenic molecules (Per a 1–Per a 10), enabling detailed characterization of allergen-specific IgE responses and improving the precision of allergy diagnosis (8, 10, 13). Although the role of cockroach allergens in human allergic disease has been extensively investigated, considerably less is known about their contribution to allergic sensitization in companion animals exposed to the same indoor environment.
Domestic dogs frequently develop naturally occurring allergic diseases, particularly canine atopic dermatitis, which shares many clinical, immunological, and pathological characteristics with human atopic disease, including IgE-mediated sensitization to environmental allergens (14, 15). Because dogs inhabit the same indoor environment as their owners while exhibiting distinct behavioral patterns, such as increased contact with floor surfaces, household dust, and organic debris around feeding and resting areas, they may experience different allergen exposure profiles despite living in the same household. Consequently, dogs have been proposed as biological sentinels of indoor environmental quality and represent a valuable comparative model for investigating environmental allergen exposure within a One Health framework (6, 16). However, whether shared household exposure results in similar or species-specific recognition of individual cockroach allergen components remains unknown. To date, no study has systematically compared molecular IgE recognition profiles to P. americana allergens between cohabiting humans and their pet dogs.
To address this knowledge gap, we conducted a One Health study involving 68 owner–dog pairs living in the same household. Household cockroach exposure was assessed using a structured environmental questionnaire, and serum IgE reactivity against P. americana allergens was analyzed by immunoblotting. We aimed to determine the frequency of cockroach allergen-specific IgE recognition, compare molecular recognition profiles between humans and dogs, and evaluate the relationship between household environmental exposures and allergen-specific IgE responses. This study provides novel insights into cross-species allergen recognition patterns and highlights the value of integrating human and veterinary perspectives to better understand the environmental determinants of allergic diseases.
[内容请查看原文]
Materials and methods
[内容请查看原文]
Ethical approval
The study protocol was approved by the Institutional Review Board of Taichung Veterans General Hospital (IRB TCVGH No: CE23070A-1/-2), and all aspects of the study conformed to the ethical guidelines of the 1975 Declaration of Helsinki. All human participants provided written informed consent before enrollment. Ethical approval was not required for pet dogs, as licensed veterinarians collected blood during routine clinical procedures.
[内容请查看原文]
Study participants and recruitment
Participants were recruited between September 2024 and July 2025 from the outpatient lobby of Taichung Veterans General Hospital, Taiwan. Dog owners visiting the hospital for medical services were approached consecutively and invited to participate if they owned at least one pet dog living in the same household. Recruitment was conducted by trained research personnel using face-to-face screening. Eligible participants who agreed to participate completed the questionnaire and provided blood samples. Their pet dogs subsequently underwent blood collection at a collaborating veterinary clinic. Each enrolled owner–dog pair represented a shared household environment for subsequent analyses.
[内容请查看原文]
Study design and questionnaire-based environmental assessment
A total of 68 human–dog dyads residing in shared household environments were enrolled to investigate patterns of allergen-specific IgE responses. To characterize the household environment and exposure levels, owners completed a structured questionnaire designed to capture demographic characteristics, allergic history, environmental exposures, and pet-related factors relevant to household allergen distribution. The survey assessed: (1) demographic characteristics of both species; (2) clinical history of allergies (e.g., dermatitis, respiratory symptoms); and (3) observed cockroach activity within the home. Specific attention was paid to “environmental interfaces” where dogs and cockroaches are likely to interact, such as kitchen areas, feeding bowls, and pet sleeping quarters.
[内容请查看原文]
Preparation of American cockroach extracts and Escherichia coli-expressed recombinant proteins
Crude extracts of Periplaneta americana (CraA) were prepared as previously described (8). These extracts served as a representative environmental allergen source reflecting household cockroach exposure.
Recombinant Per a 1-10 proteins, except Per a 8, were produced in our laboratory using Escherichia coli expression systems. Following bacterial expression, the recombinant proteins were purified by affinity chromatography using reagents supplied by Novagen (Darmstadt, Germany), according to our previously established protocols (8, 10). Per a 8 was excluded because it was infrequently detected in CraA; therefore, nine recombinant Per a allergens were included in the present analysis.
[内容请查看原文]
IgE immunoblotting and component-resolved analysis
Allergen-specific IgE reactivity to cockroach extracts was assessed by immunoblotting to enable comparative analysis across species. CraA proteins were separated by SDS–PAGE (4% stacking gel, 12% resolving gel) and transferred onto nitrocellulose membranes. Membranes were blocked with 2% bovine serum albumin in PBST and incubated overnight at 4 °C with individual sera from owners or dogs (1:5 dilution). Species-specific detection was performed using mouse anti-human IgE alkaline phosphatase–conjugated antibodies or mouse anti-canine IgE horseradish peroxidase–conjugated antibodies. Following washing, immunoreactive bands were visualized using enhanced chemiluminescence (Millipore, MA, USA) and recorded with a high-resolution gel imaging system (G:Box Chemi-XX9, SYNGENE).
Previously characterized polyclonal antibodies against nine selected Per a allergens (Per a 1–7 and Per a 9–10) were used as reference profiles to assist in identifying corresponding allergen bands in CraA (8). Per a 8 was excluded because of its low abundance and infrequent detection in CraA; therefore, nine allergen-specific antibodies were used. For each antibody, two lanes were analyzed: the left lane contained the corresponding purified recombinant Per a allergen as a positive reference, whereas the right lane contained CraA, allowing identification of the migration position of the corresponding native allergen component. These reference profiles were subsequently used to assist in assigning putative Per a allergen bands in the serum IgE immunoblots.
Because the volume of serum that could be ethically collected from pet dogs was limited, the available canine samples were prioritized for qualitative immunoblot analyses. Comprehensive immunoblot inhibition assays, quantitative canine allergen-specific IgE measurements, and validation of all allergen components were therefore not feasible. Accordingly, the present study focused on comparative IgE recognition patterns between paired human and dog sera rather than on quantitative assessment of canine allergen-specific IgE responses. Accordingly, the present study focused on comparative IgE recognition rather than comprehensive characterization of the canine allergen repertoire.
[内容请查看原文]
Statistical analysis
Statistical analyses were performed using SPSS Statistics version 22. Allergy prevalence was expressed as percentages. Chi-squared tests were used to assess associations between allergic status in owners and their dogs, reflecting shared household exposure. Logistic regression analysis was applied to evaluate the relationship between environmental factors and allergy prevalence across species. A p-value of < 0.05 was considered statistically significant.
[内容请查看原文]
Results
[内容请查看原文]
Household-based characteristics of human–dog dyads
A total of 68 owner–dog pairs sharing the same household environment were included in this study. The demographic and allergy-related characteristics of owners and their pets are summarized in Table 1. Among owners, the mean age was 34.10 ± 10.84 years, with a predominance of female participants (79.41%). A history of allergic disease was reported by 82.35% of owners. Notably, 16.18% of owners self-reported a worsening of allergic symptoms following the introduction of a pet dog into the household, suggesting a perceived interaction between pet ownership and allergic disease expression in a shared indoor environment. Among pet dogs, 66.18% were reported by their owners to have experienced allergic symptoms.
Table 1. Demographic and allergy characteristics of dog owners and their pets ( N = 68).
| Characteristic | Owners ( n = 68) | Dogs ( n = 68) |
|---|---|---|
| Mean age, years (±SD) | 34.10 (±10.84) | 5.54 (±3.81) |
| Sex, %, male/female | 20.59/79.41 | 45.59/54.41 |
| Residential duration, years (±SD) | 8.83 (±10.64) | – |
| History of allergy, % | 82.35 | 66.18 |
| Self-reported worsening of allergy after dog ownership, % | 16.18 | – |
When allergy status was examined at the household level, more than half of the dyads (52.94%, 36/68) exhibited concurrent allergic conditions in both the owner and the dog (Table 2). This high rate of co-occurrence suggests that shared household environmental exposure may contribute to the allergic health of the multi-species household. Dyads in which only the owner reported allergies accounted for 29.41%, while dyads with allergic dogs but non-allergic owners comprised 13.23%. Only 4.41% of households reported no allergic symptoms in either species. These findings indicate a high degree of overlap in allergic manifestations within shared domestic environments.
Table 2. Distribution of sample numbers in the owner–dog allergy matrix by owner self-assessment ( N = 68).
| Allergic disease status in dogs | Owner without self-reported allergy | Owner with self-reported allergy |
|---|---|---|
| Dog without allergic disease | N = 3 (4.41%) | N = 20 (29.41%) |
| Dog with allergic disease | N = 9 (13.23%) | N = 36 (52.94%) |
[内容请查看原文]
Environmental evidence of household cockroach exposure
Questionnaire-based assessment revealed widespread household exposure to cockroaches among participating human–dog dyads (Table 3). Cockroach activity was most frequently reported in kitchens (61.43%), followed by living rooms (30.43%), bedrooms (18.84%), and bathrooms (11.59%). In addition to general household areas, evidence of cockroach activity was reported in dog-associated micro-environments, including areas near feeding bowls (10.00%) and dog sleeping areas (4.29%), indicating potential shared exposure pathways for both humans and companion animals within the same domestic setting.
Table 3. Household cockroach exposure characteristics in human–dog shared environments ( N = 68).
| Characteristic | n (%) |
|---|---|
| Section A. Household pest management and dog-related factors | |
| Cockroach bait placed in household | 42.86 |
| Dog observed catching cockroaches | 31.88 |
| Increased cockroach sightings after dog ownership | 8.57 |
| Section B. Locations of cockroach infestation within households | |
| Kitchen | 61.43 |
| Living room | 30.43 |
| Bedroom | 18.84 |
| Bathroom | 11.59 |
| Section C. Evidence of cockroach activity in dog-associated areas | |
| Near dog feeding bowls | 10.00 |
| Near dog sleeping areas | 4.29 |
Regarding household pest management and animal-related factors, 42.86% of owners reported placing cockroach bait in the household, while 31.88% observed their dogs catching cockroaches. Among the owners, 8.57% reported more frequent cockroach sightings after dog ownership. This observation may reflect changes in household environmental conditions associated with pet keeping, including the availability of pet food residues and other organic materials around feeding areas. When feeding areas and food residues are not adequately cleaned, such conditions may provide additional food resources for cockroaches and potentially increase their activity or visibility. However, because cockroach infestation was not objectively quantified in the present study, this association should not be interpreted as evidence that dog ownership directly causes or increases cockroach infestation.
Taken together, the questionnaire data indicate that allergic symptoms in humans and dogs frequently co-occur within the same household and are associated with shared environmental exposure to cockroach infestation.
[内容请查看原文]
Comparative IgE recognition profiles to cockroach allergens
To characterize molecular IgE recognition patterns, allergen-specific IgE reactivity to Periplaneta americana crude extracts (CraA) was examined in sera from owners and their pet dogs. Representative immunoblotting profiles from 56 owner–dog pairs are shown in Supplementary Figure S1. As shown in Figure 1A, polyclonal antibodies against Per a 1–10, except Per a 8, were first used to identify the corresponding allergen positions in the CraA. Based on these reference positions, serum samples from owners and their dogs were subsequently analyzed to establish their IgE-binding profiles, with representative results shown in Figures 1B,C, respectively.
[图：Comparative IgE recognition of Periplaneta Americana crude allergen extract (CraA) in human owners and their pet dogs. (]
Immunoblot analysis identified several major IgE-reactive cockroach allergen components that were recognized by paired human and canine sera. The frequencies of IgE recognition of individual cockroach allergen components are summarized in Figure 2. Among owners, the most frequently recognized allergens were Per a 1 (34%) and Per a 3 (34%), followed by Per a 7 (26%) and Per a 4 (18%). IgE reactivity was also detected against Per a 2 (9%) and Per a 9 (9%), whereas no detectable IgE reactivity was observed against Per a 5, Per a 6, or Per a 10. In contrast, pet dogs exhibited markedly higher IgE recognition frequencies for Per a 4 (69%), Per a 1 (63%), and Per a 9 (40%). Reactivity to Per a 3 (9%) and Per a 10 (6%) was comparatively low in dogs. Minimal or no IgE binding to Per a 5 and Per a 6 was observed in either species.
[图：Prevalence of IgE recognition of selected P. Americana allergen components. The bar chart illustrates the percentage of ]
Taken together, these findings indicate that the major overlapping IgE-recognized allergens between owners and dogs are Per a 1, Per a 3, Per a 4, and Per a 9. Notably, dogs showed higher IgE recognition frequencies for Per a 4, Per a 1, and Per a 9, whereas owners showed higher IgE reactivity recognition frequencies for Per a 3, and Per a 7, highlighting both shared and distinct IgE recognition patterns between the two species.
[内容请查看原文]
Discussion
This study provides a comparative analysis of cockroach allergen recognition in cohabiting human–dog pairs. By integrating comparative IgE immunoblot analysis with household environmental survey data, we demonstrated that although owners and their pet dogs frequently shared allergic conditions, they exhibited distinct allergen recognition profiles. To our knowledge, this is the first study to characterize species-specific IgE recognition patterns to American cockroach allergens in paired humans and companion dogs living in the same household.
[内容请查看原文]
The shared household as a one health micro-ecosystem
Our findings underscore the concept of the household as a shared micro-ecosystem where humans and animals are subject to the same environmental stressors. The high rate of concurrent allergic conditions (52.92%) within the dyads suggests that cockroach infestation is not merely a human health issue but a pervasive environmental hazard affecting all mammalian inhabitants. The kitchen was identified as the primary reservoir for P. americana (61.43%), but the identification of cockroach activity near feeding bowls (10%) and sleeping areas (4.29%) reveals a specific exposure pathway for dogs. Our results are consistent with previous studies showing a positive correlation between domestic cockroach exposure and the likelihood of cockroach allergen-specific IgE recognition (5, 17). These behaviors may increase dogs' opportunities for repeated contact with household dust and surfaces potentially contaminated with cockroach allergens.
Because environmental allergen concentrations could not be reliably quantified, household cockroach exposure in the present study was evaluated using standardized questionnaires describing infestation sites and owner-reported evidence of cockroach activity. These measures represent surrogate indicators of environmental exposure rather than direct allergen quantification.
[内容请查看原文]
Species-specific molecular signatures: per a 4 and per a 9 in dogs
A pivotal discovery of this research is the interspecies discrepancy in IgE recognition profiles toward allergens Per a 1–10. While Per a 1 and Per a 3 were common antigens for both species, pet dogs exhibited a strikingly higher prevalence of IgE reactivity to Per a 4 (69%) and Per a 9 (40%). In contrast, owners showed higher IgE recognition frequencies for Per a 3 and Per a 7. These differences likely result from multiple biological processes, including species-specific exposure behaviors, epithelial barrier function, antigen uptake, and immune processing (18, 19).
The predominance of Per a 4 (a lipocalin-like protein) and Per a 9 (arginine kinase) recognition in dogs may reflect differences in exposure behavior rather than differences in household allergen sources. Dogs spend prolonged periods in close contact with floor surfaces through sniffing, licking, resting, and feeding behaviors, increasing their opportunity for repeated exposure to household dust and cockroach-associated microenvironments (20–22). In support of this observation, dogs from households reporting cockroach activity near feeding bowls showed higher frequencies of IgE recognition to Per a 4 and Per a 9. Although environmental allergen concentrations were not directly measured in the present study, these findings suggest that shared household exposure does not necessarily result in identical allergen recognition profiles. Instead, species-specific behavioral exposure, together with differences in antigen processing and immune responses, may contribute to the distinct IgE recognition patterns observed between humans and dogs (23, 24).
[内容请查看原文]
Potential differences in allergen exposure and IgE recognition pathways between humans and dogs
Although humans and dogs shared the same household environment, their allergen-specific IgE recognition profiles differed considerably, suggesting that environmental exposure alone does not fully explain species-specific IgE responses observed between the two species. Instead, differences in allergen exposure routes, host biological characteristics, and behavioral patterns may contribute to differential allergen recognition.
One possible explanation is the difference in the primary route of allergen exposure. In humans, inhalation is generally regarded as an important route of exposure to indoor aeroallergens, including cockroach allergens, with effects on the upper and lower respiratory tracts. In contrast, companion dogs frequently contact floor surfaces through walking, lying, sniffing, and grooming, resulting in frequent contact of the skin and oral mucosa with environmental materials that may contain allergens. Experimental studies have demonstrated that epicutaneous allergen exposure can induce allergen-specific IgE responses and promote allergic inflammation, particularly when epithelial barrier integrity is impaired (9, 12).
Species-specific characteristics of the epithelial barrier may further influence allergen uptake and subsequent IgE recognition. Canine atopic dermatitis is associated with impaired skin barrier function, altered lipid composition, and increased transepidermal water loss, changes that may facilitate allergen penetration and immune activation (25). Similar mechanisms have been described in human atopic dermatitis, although the relative contribution of respiratory and cutaneous exposure may differ between species (15). Consequently, exposure to the same household allergen source may result in differences in antigen uptake, processing, and IgE recognition.
In addition, differences in innate immune responses, antigen presentation, and behavioral exposure may further shape allergen recognition profiles. These factors may contribute to the higher frequencies of IgE recognition of Per a 4 and Per a 9 observed in dogs, whereas owners showed greater IgE recognition of Per a 3 and Per a 7. However, because the present study did not directly assess allergen exposure routes, epithelial barrier function, antigen presentation, or IgE production, these mechanisms should be considered hypotheses rather than experimentally demonstrated pathways. Future studies integrating standardized environmental allergen quantification, epithelial barrier biomarkers, and longitudinal monitoring of human–dog dyads will be valuable for clarifying the biological mechanisms underlying the distinct IgE recognition patterns observed between species.
[内容请查看原文]
Dogs as biological sentinels of household allergen exposure
From a comparative allergy perspective, our findings suggest that pet dogs may serve as biological sentinels of household allergen exposure. Dogs spend prolonged periods in close contact with floor surfaces, household dust, and pet-associated microenvironments, resulting in greater cumulative exposure to environmental allergens than their owners. Consequently, alterations in canine IgE recognition profiles may reflect changes in household allergen burden before similar patterns become clinically apparent in humans (12, 26). Although additional longitudinal studies are required, our findings support the hypothesis that companion dogs may function as practical biological sentinels for monitoring household allergen exposure and may complement conventional environmental assessments.
[内容请查看原文]
Implications for integrated pest and allergen management
The results of this study may have implications for public health and veterinary practice. Standard pest control measures often focus on visible human-centric areas. However, our study highlights the need for “Integrated Pest Management” that specifically addresses pet-related interfaces, such as regular cleaning of feeding stations and sleeping quarters. Reducing cockroach infestation in these hotspots is essential not only for managing canine atopic dermatitis but also for mitigating the cumulative allergen load within the shared domestic environment, thereby protecting the health of the entire dyad.
[内容请查看原文]
Limitations and future directions
A limitation relates to the restricted volume of canine serum that could be collected under ethical and clinical considerations. Consequently, analyses were prioritized for comparative immunoblotting, and comprehensive canine allergen-specific IgE quantification, immunoblot inhibition assays, and evaluation of additional allergen components were not feasible. Therefore, the present study characterizes comparative IgE recognition patterns rather than providing direct evidence of allergen cross-reactivity or the complete spectrum of canine cockroach allergen-specific IgE recognition.
A further limitation is that environmental cockroach allergen concentrations were not included in the final analysis. Household dust samples were collected by dog owners rather than by trained study personnel using a standardized sampling protocol. Consequently, substantial variability in sampling location, surface area, collection method, and the amount and quality of dust obtained limited the comparability and reliability of quantitative ELISA measurements. After evaluation of the available specimens and assay performance, these measurements were not considered sufficiently reliable for inclusion in the analysis. Therefore, the household questionnaire data should be interpreted as an assessment of reported cockroach exposure rather than a quantitative measure of environmental allergen burden. Future studies should employ standardized, prospectively supervised dust collection and validated quantitative allergen assays to directly relate environmental allergen levels to component-specific IgE recognition in human–dog dyads.
Although analysis of nine selected allergens could not fully capture the molecular IgE recognition profile of P. americana, for which 23 allergens are currently registered in the WHO/IUIS Allergen Nomenclature Database (http://www.allergen.org), it was sufficient to address the primary comparative objective of this study. Specifically, our findings demonstrate that humans and dogs sharing the same household environment exhibit distinct allergen-specific IgE recognition patterns.
Together, these findings suggest that paired human–dog investigations provide a useful translational model for understanding environmental allergen-specific IgE recognition and may facilitate future comparative studies in both veterinary and human allergy research. Such studies may help distinguish differences in exposure routes from intrinsic species-specific immune responses.
[内容请查看原文]
Conclusions
In conclusion, humans and their cohabiting pet dogs exhibit both shared and species-specific IgE recognition of American cockroach allergens despite living in the same household environment. These findings provide new insights into comparative allergy and support the use of paired human–dog studies to investigate household allergen exposure and allergic disease.