van Boven Frank E, de Jong Nicolette W, Braunstahl Gert-Jan, Gerth van Wijk Roy, Arends Lidia R
1Department of Internal Medicine, Section of Allergology & Clinical Immunology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
Department of Pulmonology, Sint Franciscus Vlietland Groep, P.O. Box 10900, 3004 BA Rotterdam, The Netherlands.
Clin Transl Allergy. 2020 Jan 6;10:2. doi: 10.1186/s13601-019-0306-3. eCollection 2020.
Evidence regarding the clinical effectiveness of mite allergen avoidance for the treatment of asthma is lacking. In previous meta-analyses on mite allergen control, the baseline data were not discussed in detail. This study updates and extends the existing Cochrane review by Gøtzsche and Johansen (Cochrane Database of Systematic Reviews, 2008, Art. No: CD001187), with a focus on baseline asthma outcomes and allergen exposures.
We used the existing trials in the original Cochrane review and included newly published studies. The baseline data for the mite allergen load from the mattress, the standardized asthma symptom score (ASS), the forced expiratory volume in 1 s percentage of predicted (FEV %pred.), and the histamine provocative concentration causing a 20% drop in FEV (PC) were extracted. First, the mean values of the outcomes were calculated. The influence of the mite allergen load was examined with a random-effect meta-regression using the Metafor package in R.
Forty-five trials were included; 39 trials reported strategies for concurrent bedroom interventions, and 6 trails reported strategies for air purification. The mite allergen load ranged from 0.44 to 24.83 μg/g dust, with a mean of 9.86 μg/g dust (95% CI 5.66 to 14.05 μg/g dust, I = 99.8%). All health outcomes showed considerable heterogeneity (standardized ASS mean: 0.13, 95% CI 0.08 to 0.18, I = 99.9%; FEV %pred. mean: 85.3%, 95% CI 80.5 to 90.1%, I = 95.8%; PC mean: 1.69 mg/mL, 95% CI 0.86 to 2.52 mg/mL, I = 95.6%). The covariate mite allergen load did not significantly influence health outcomes.
This meta-analysis shows that mite avoidance studies are characterized by the inclusion of patients with rather mild to moderate asthma and with varying and sometimes negligible levels of allergen exposure. Future studies should focus on patients with severe asthma and increased levels of allergen exposure.
缺乏关于避免螨过敏原治疗哮喘临床有效性的证据。在之前关于螨过敏原控制的荟萃分析中，未详细讨论基线数据。本研究更新并扩展了Gøtzsche和Johansen（《Cochrane系统评价数据库》，2008年，编号：CD001187）现有的Cochrane综述，重点关注哮喘的基线结局和过敏原暴露情况。
我们使用了原始Cochrane综述中的现有试验，并纳入了新发表的研究。提取了床垫上螨过敏原负荷的基线数据、标准化哮喘症状评分（ASS）、第1秒用力呼气容积占预计值的百分比（FEV %pred.）以及导致FEV下降20%的组胺激发浓度（PC）。首先，计算结局的平均值。使用R语言中的Metafor软件包通过随机效应荟萃回归分析螨过敏原负荷的影响。
纳入了45项试验；39项试验报告了卧室同步干预策略，6项试验报告了空气净化策略。螨过敏原负荷范围为0.44至24.83μg/g灰尘，平均为9.86μg/g灰尘（95%置信区间5.66至14.05μg/g灰尘，I² = 99.8%）。所有健康结局均显示出相当大的异质性（标准化ASS平均值：0.13，95%置信区间0.08至0.18，I² = 99.9%；FEV %pred.平均值：85.3%，95%置信区间80.5至90.1%，I² = 95.8%；PC平均值：1.69mg/mL，95%置信区间0.86至2.52mg/mL，I² = 95.6%）。协变量螨过敏原负荷对健康结局无显著影响。
这项荟萃分析表明，避免螨的研究纳入的患者多为轻度至中度哮喘患者，且过敏原暴露水平各不相同，有时可忽略不计。未来的研究应聚焦于重度哮喘患者和过敏原暴露水平增加的患者。
