Division of Allergy, Immunology, and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
Rho, Inc., Durham, NC, USA.
Pediatr Allergy Immunol. 2021 Jul;32(5):971-979. doi: 10.1111/pai.13480. Epub 2021 Mar 20.
Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma.
Ten adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells.
67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated.
We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.
鼻内变应原激发（NAC）可能是评估变应原特异性治疗的适应证和/或结果的一种手段，特别是针对常年性变应原。在患有哮喘的儿童中，NAC 并不常见，蟑螂 NAC 也尚未得到充分证实。本研究的目的是确定一系列诱导鼻部症状的德国蟑螂提取物剂量，并评估蟑螂 NAC 在患有哮喘的儿童中的安全性。
10 名成年人（18-37 岁）和 25 名儿童（8-14 岁），这些儿童患有控制良好的持续性哮喘和蟑螂致敏，接受了稀释剂 NAC 后，接受了多达 8 个递增剂量的蟑螂提取物（0.00381-11.9µg/mL Bla g 1）。NAC 结果通过总鼻部症状评分（TNSS）和/或喷嚏评分确定。蟑螂过敏原诱导的 T 细胞活化和 IL-5 产生在外周血单核细胞中进行测量。
67%（6/9）的成年人和 68%（17/25）的儿童在 Bla g 1 的中位反应剂量为 0.120µg/mL[中位数范围 0.0380-0.379µg/mL]时 NAC 呈阳性。此外，3 名儿童单独对稀释剂有反应，未接受任何蟑螂提取物。总体而言，32%（11/34）仅通过喷嚏呈阳性，15%（5/34）仅通过 TNSS 呈阳性，21%（7/34）同时通过两项标准呈阳性。在基线时，NAC 反应者的蟑螂特异性 IgE 更高（P=0.03），蟑螂特异性 IgG/IgE 比值更低（儿童，P=0.002），并且蟑螂特异性产生 IL-5 的 T 淋巴细胞增加（P=0.045）。NAC 耐受性良好。
我们报告了为持续性哮喘和蟑螂致敏的儿童开发 NAC 的方法。这种 NAC 可以被视为一种工具，用于确认临床上相关的致敏，并评估治疗研究中的反应。
