赤潮毒素（短裸甲藻毒素）气溶胶与哮喘
2007/03/12
随着哮喘发病率的不断增高，人们对于可能诱发哮喘发作的环境因素也越来越加以关注。海洋微藻类，腰鞭毛藻，大量繁殖后，每年可在墨西哥湾引发赤潮。腰鞭毛藻可产生大量天然聚醚类毒素，称为短裸甲藻毒素。短裸甲藻毒素为Na+通道阻滞剂，且可能为组织胺激动剂。在动物实验中，短裸甲藻毒素可引起明显的支气管收缩。有报道度假期间或职业性接触佛罗里达赤潮气溶胶者，尤其是哮喘患者，可引发明显的呼吸道症状。
Lora E. Fleming等对97例哮喘患者（≥12岁）在海滩上接触腰鞭毛藻前及1h后的肺功能测定及哮喘问卷结果进行了研究，研究同时进行环境监测，对海水和空气进行取样，以及对每例患者进行短裸甲藻毒素监测。
研究结果发现，接触腰鞭毛藻后比接触前更易产生呼吸道症状，FEV1、呼气中期流速、峰流速轻度下降（统计学上有显著差异），尤其是常规应用哮喘药物治疗者。在无佛罗里达赤潮发生时，则无上述差异。
作者由此得出结论，哮喘患者，尤其是接受常规治疗的哮喘患者，在接触佛罗里达赤潮毒素气溶胶后可导致肺功能下降。这些毒素的长期效应以及对其亚群毒性的评估尚需进一步的研究。
（ 赵海涛 沈阳军区总医院呼吸内科 110016 摘译）
(CHEST 2007，131：187-194)
Aerosolized Red-Tide Toxins (Brevetoxins) and Asthma*
Lora E. Fleming, MD, PhD, MPH, MSc; Barbara Kirkpatrick, EdD; Lorraine C. Backer, PhD, MPH; Judy A. Bean, PhD; Adam Wanner, MD, FCCP; Andrew Reich, MS; Julia Zaias, DVM, PhD; Yung Sung Cheng, PhD; Richard Pierce, PhD; Jerome Naar, PhD; William M. Abraham, PhD and Daniel G. Baden, PhD
Abstract
Background: With the increasing incidence of asthma, there is increasing concern over environmental exposures that may trigger asthma exacerbations. Blooms of the marine microalgae, Karenia brevis, cause red tides (or harmful algal blooms) annually throughout the Gulf of Mexico. K brevis produces highly potent natural polyether toxins, called brevetoxins, which are sodium channel blockers, and possibly histamine activators. In experimental animals, brevetoxins cause significant bronchoconstriction. In humans, a significant increase in self-reported respiratory symptoms has been described after recreational and occupational exposures to Florida red-tide aerosols, particularly among individuals with asthma.
Methods: Before and after 1 h spent on beaches with and without an active K brevis red-tide exposure, 97 persons 12 years of age with physician-diagnosed asthma were evaluated by questionnaire and spirometry. Concomitant environmental monitoring, water and air sampling, and personal monitoring for brevetoxins were performed.
Results: Participants were significantly more likely to report respiratory symptoms after K brevis red-tide aerosol exposure than before exposure. Participants demonstrated small, but statistically significant, decreases in FEV1, midexpiratory phase of forced expiratory flow, and peak expiratory flow after exposure, particularly among those participants regularly using asthma medications. No significant differences were detected when there was no Florida red tide (ie, during nonexposure periods).
Conclusions: This study demonstrated objectively measurable adverse changes in lung function from exposure to aerosolized Florida red-tide toxins in asthmatic subjects, particularly among those requiring regular therapy with asthma medications. Future studies will assess these susceptible subpopulations in more depth, as well as the possible long-term effects of these toxins.
Key Words: asthma·brevetoxins·harmful algal blooms·Karenia brevis·red tides·sensitive populations·spirometry
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哮喘联合治疗的有效性：一项观察性研究
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哮喘急性发作患者的肺功能测定结果
