Mourao Elizabeth Maria Mercer, Rosario Nelson Augusto
Department of Pediatrics, Federal University of Parana, Curitiba, Brazil.
Front Allergy. 2021 May 7;2:673462. doi: 10.3389/falgy.2021.673462. eCollection 2021.
Conjunctival provocation test (CPT) is used to demonstrate clinical relevance to a specific allergen. (Bt) is a prevalent allergen in tropical regions. Its major allergen is commonly detected in house dust in Brazil. Patients with allergic rhinoconjunctivitis (ARC) have IgE antibodies to Bt although it may not indicate clinical allergy. The purpose of this study is to demonstrate the role of CPT in clinical allergy to Bt in allergic conjunctivitis (AC). CPT was performed in asymptomatic subjects with ARC ( = 26) outside the grass pollen season. They had positive skin prick tests (SPT) to Bt and other common inhalant allergens and they were off topical or systemic antihistamines. Standardized allergens were used for CPT (Blo t 5 462.5 ng/mL in 1:1 solution, Alk Abelló). CPT was conducted on a control group of subjects ( = 29) without symptoms of ARC and with negative SPT. CPT was performed with progressive doses of allergen solutions in normal saline (1:32, 1:16, 1:8, 1:4, 1:2). CPT with the same allergen dose that elicited a positive reaction was repeated one week later. The protocol was approved by the local Ethics Board and signed informed consent was obtained from all participants. There were 92% (24/26) of positive CPT in subjects sensitized to Bt. Significant association was found between SPT and CPT results with Bt ( < 0.0001). CPT had 92% sensitivity and 100% specificity when compared to SPT results. Positive reactions with the same dose or one immediately higher occurred in 21 out of 22 subjects who repeated TPC 1 week later. Mild transient nasal symptoms (21/24) were the major side effects of positive CPT followed by moderate periorbital edema which occurred in 41% (10/24). One controlled asthmatic BT-sensitized subject developed wheezing and dyspnea during a positive CPT with Bt that cleared with inhaled albuterol (400 mcg). There were no reactions whatsoever of CPT in non-allergic subjects. This study demonstrated that Bt may cause allergic conjunctivitis in our population. In addition, CPT is a safe and reproducible test if standardized allergens are used.
结膜激发试验（CPT）用于证明对特定过敏原的临床相关性。巴西曲霉（Bt）是热带地区一种常见的过敏原。在巴西，其主要过敏原通常能在室内灰尘中检测到。过敏性鼻结膜炎（ARC）患者体内有针对巴西曲霉的IgE抗体，尽管这可能并不表明存在临床过敏。本研究的目的是证明CPT在过敏性结膜炎（AC）患者对巴西曲霉的临床过敏中的作用。在草花粉季节之外，对26例无症状的ARC患者进行CPT。他们对巴西曲霉和其他常见吸入性过敏原的皮肤点刺试验（SPT）呈阳性，且未使用局部或全身性抗组胺药。CPT使用标准化过敏原（Alk Abelló公司的Blo t 5 462.5 ng/mL，1:1溶液）。对29例无ARC症状且SPT阴性的受试者作为对照组进行CPT。CPT采用在生理盐水中逐步递增剂量的过敏原溶液（1:32、1:16、1:8、1:4、1:2）进行。一周后，对引起阳性反应的相同过敏原剂量重复进行CPT。该方案经当地伦理委员会批准，所有参与者均签署了知情同意书。对巴西曲霉致敏的受试者中，92%（24/26）的CPT呈阳性。发现巴西曲霉的SPT和CPT结果之间存在显著相关性（P<0.0001）。与SPT结果相比，CPT的敏感性为92%，特异性为100%。在22例一周后重复CPT的受试者中，21例对相同剂量或更高一级剂量出现阳性反应。轻度短暂的鼻部症状（21/24）是CPT阳性的主要副作用，其次是41%（10/24）的受试者出现中度眶周水肿。一名对巴西曲霉致敏的哮喘患者在CPT阳性时出现喘息和呼吸困难，吸入沙丁胺醇（400 mcg）后症状缓解。非过敏受试者的CPT未出现任何反应。本研究表明，巴西曲霉可能在我们的人群中引起过敏性结膜炎。此外，如果使用标准化过敏原，CPT是一种安全且可重复的检测方法。
