哮喘联盟

    回顾目的：出生前和围产期事件可以增加对过敏性疾病和早期呼吸道疾病发生率的影响。
    最近的发现：去年的研究提示宫内暴露，包括烟草烟雾的暴露、饮食暴露包括维生素D、出生前感染、以及细菌产物的暴露可以调整特应质和呼吸系统疾病。已经有研究提示，X基因会受到环境因素炎症通路基因和宫内被动吸烟的相互影响。也有研究显示，出生前暴露于内毒素可以起到保护作用。另一方面，近期的研究显示胎膜炎症可以增加早产儿发生喘息的风险。最后，两个大样本的离体队列研究评价了母体孕期的饮食，并建议维生素D水平可以保护性的对抗哮喘和喘息。
    概要：出生前众多的影响因素对出生后早期呼吸道疾病发生率的关系还需要流行病学的证据。这些因素的影响机制还需要更多的研究，以及对肺发育、过敏性和非过敏性炎症、气道重塑影响等多条途径。早期那些可以诱发喘息的因素将会转变为增加哮喘的风险。

（苏楠 卫生部中日友好医院呼吸内科 100029 摘译）
（Curr Opin Pediatr. 2008 Dec;20(6):682-6877）

Curr Opin Pediatr. 2008 Dec;20(6):682-7.
 
Prenatal factors and the development of asthma.

Kumar R.
Division of Allergy and Immunology, Children’s Memorial Hospital, Chicago, Illinois, USA. rkumar@childrensmemorial.org

PURPOSE OF REVIEW: There is increasing evidence that both prenatal and perinatal events influence both allergic diseases and early-life respiratory morbidity. 
RECENT FINDINGS: Studies in the last year have suggested that in-utero exposures including tobacco smoke exposure, dietary exposures including vitamin D, and prenatal infection and exposure to microbial products may modulate both atopy and respiratory disease. There have been studies revealing gene x environment interactions between inflammatory pathway genes and in-utero smoke exposure. There have also been studies which have revealed that prenatal exposure to endotoxin may be protective. On the other hand, a recent study also suggested that chorioamnionitis may increase the risk of recurrent wheezing in combination with preterm birth. Finally, two separate large cohort studies evaluated maternal diet in pregnancy and suggested that vitamin D levels may be protective against asthma and wheezing. 
SUMMARY: There is epidemiological evidence for multiple prenatal factors impacting early-life respiratory morbidity. The mechanisms of these factors need further investigation and may act via various pathways which include effects on lung development, allergic and nonallergic inflammation, and airway remodeling. It remains to be determined if some of these early-life factors which predispose to wheezing will all translate into increased risk of asthma.