细菌定植/感染在婴幼儿喘息性疾病中的作用

喘息是婴幼儿时期最常见的呼吸系统临床表现之一,引起喘息的疾病包括毛细支气管炎、间质性肺炎、支气管哮喘等.目前认为病毒感染是诱发婴幼儿喘息最主要的因素,细菌在婴幼儿喘息中的作用尚不明确.近年来研究发现喘息性疾病患儿呼吸道通常合并细菌定植/感染,新生儿早期下呼吸道细菌定植在婴幼儿喘息性疾病的转归中起着重要作用,仍存在争议.     

病毒感染与婴幼儿喘息性疾病

婴幼儿喘息性疾病的发病率逐年上升,病毒感染是诱发婴幼儿喘息的重要因素,这一观点已得到国内外学者的普遍认可。探讨病毒感染引起婴幼儿喘息的机制,对于婴幼儿喘息的干预与转归有重要意义。本文介绍几种常见病毒感染的特点及研究进展。近几年,新发现的人偏肺病毒、人博卡病毒也可引起婴幼儿喘息。本文将其相关研究作一介绍。     

呼吸道常见病毒和新型病毒感染与婴幼儿喘息性疾病的关系

呼吸道病毒感染是诱发婴幼儿喘息的重要因素,常造成反复喘息,且日后发生支气管哮喘的风险显著增加.最新的研究发现某些新型呼吸道病毒如博卡病毒、人类偏肺病毒等与婴幼儿喘息有关,给哮喘的防治提出了新的课题和研究内容.文章就近年来在婴幼儿喘息性疾病中常见病毒和某些新型病毒感染与哮喘、特应质之间的关系,以及病毒感染的病原学、致病机制等研究进展进行阐述.     

婴幼儿肺功能测定及其在喘息性疾病中的应用

喘息性疾病是婴幼儿时期的常见病,引起婴幼儿喘息的原因比较多.在婴幼儿进行肺功能测定,对判别喘息的类型、协助诊断、监测病程进展及预后具有重要意义.近十余年来随着肺功能检测技术的迅速发展,很多肺功能检查项目已经可以在婴幼儿进行,如流速-容量曲线法、阻断法、婴幼儿体描仪法等.检查的具体内容与年长儿及成人类似,包括肺容积、通气功能、呼吸力学、支气管舒张试验及支气管反应性测定等.本文就目前可在婴幼儿进行的肺功能检测技术的原理、方法及其参数在喘息性疾病中改变的特点及其临床意义作一简介.     

婴幼儿喘息与呼吸道合胞病毒肺炎支原体感染及过敏的关系

目的了解婴幼儿喘息性疾病与呼吸道合胞病毒、肺炎支原体感染的关系,同时进行常见食物过敏原和吸入过敏原筛查,旨在探讨婴幼儿喘息与呼吸道合胞病毒、肺炎支原体感染及过敏的关系及其与支气管哮喘的相关性。方法对2000-01—2003-12在南京中医药大学附属医院就诊的232例下呼吸道感染的婴幼儿进行呼吸道合胞病毒、肺炎支原体抗体的检测,并进行过敏原检测,收集特异性体质的表现及家族史,对有喘息症状的部分患儿进行随访。结果喘息组患儿以上2种病原体感染率高于非喘息组;81例喘息患儿随访中,有67.90%(55例)的患儿转为哮喘,这部分患儿的特应性体质表现及家族史与发病密切相关。结论婴幼儿喘息性疾病与呼吸道合胞病毒、肺炎支原体感染密切相关,过敏是婴幼儿反复发生喘息性疾病的重要危险因素。     

婴幼儿喘息诊治进展

婴幼儿喘息是一种异质性疾病,可分为婴幼儿暂时性喘息、非过敏性持续性喘息和过敏性喘息(即哮喘).婴幼儿暂时性喘息主要与先天性支气管肺发育不良等因素有关,非过敏性持续性喘息主要与病毒感染引起的炎症有关,这一炎症参与的细胞主要是嗜中性粒细胞和淋巴细胞,而哮喘参与的细胞主要是嗜酸性粒细胞.婴幼儿期喘息的发作次数不是诊断哮喘的理想指标,婴幼儿期哮喘的诊断应重视过敏性疾病的遗传背景、个人过敏性疾病史、实验室过敏指标的检查及对支气管扩张剂治疗的反应.在不能明确婴幼儿喘息类型的情况下,联合应用激素、β2肾上腺素能受体激动剂、白三烯受体调节剂和组织胺H1受体阻断剂治疗是一个有效的选择.     

对婴幼儿反复喘息的再认识

喘息是婴幼儿最为常见的呼吸道症状之一,可伴随呼吸困难和咳嗽,常见于毛细支气管炎。由于婴幼儿气道发育尚不完善,喘息常常反复发生。有专家认为,婴幼儿反复喘息(recurrent wheezing)在除外异物、纵隔占位等其他喘息性疾病后要考虑支气管哮喘,并主张早期激素吸入治疗。那么,是不是所有的婴幼儿反复喘息都是哮喘?这些患儿是否都该接受激素治疗呢?     

婴幼儿喘息性疾病尿MA、TRF、IgG、α1-MG的测定及临床意义

目的　 了解婴幼儿喘息性疾病患儿的肾小球和肾小管功能损害情况。 方法 　应用速率免疫散射比浊法测定尿MA、TRF、IgG、α1 MG。尿肌酐测定用碱性苦味酸速率法。 结果 　婴幼儿喘息性疾病尿MA、TRF、IgG、α1 MG排泄率 ,与正常对照组比较均有非常显著性差异 (P <0 0 1)。 结论 　婴幼儿喘息性疾病可能存在肾小球和肾小管功能早期一过性损伤。对临床用药有指导意义。     

喘息性疾病患儿过敏原检测分析

目的分析喘息性疾病婴幼儿过敏情况,以利早期干预治疗。方法用UniCAP全自动检测仪和皮肤点刺试验对243例喘息性疾病婴幼儿(毛细支气管炎、伴喘息的支气管炎或肺炎、婴幼儿哮喘)进行过敏原筛查和特异性IgE测定。结果1.婴儿期过敏原以食物为主(P=0.03),幼儿期气媒性过敏原阳性率达67.2%;婴幼儿期主要的食物过敏原为牛奶、鸡蛋白;气媒性过敏原是户尘螨。2.进行过敏原特异性IgE测定时,皮肤点刺试验阳性比例低(0～37.5%)。结论婴儿出生后即食入蛋白质,胃肠道功能未健全,易发生食物过敏;幼儿期添加易致敏食物,且在户外时间增多,食物和吸入性过敏均明显。UniCAP系统是一种用于筛查和寻找变应原的较为准确的方法。     

喘息性疾病患儿血清特异性IgE测定及临床意义

目的研究喘息性疾病患儿血清特异性IgE(sIgE)的变化,为喘息性疾病的治疗和预防提供可靠的科学依据。方法采用酶联免疫分析法对324例喘息患儿进行血清总IgE及sIgE的测定,综合分析其在喘息发生发展中的作用机制。结果婴幼儿以食物性过敏为主,而年长儿以吸入性过敏为主。反复喘息发作患儿血清总过敏原和单一sIgE均高于非反复发作者。反复喘息发作患儿血清总IgE阳性者其首次喘息发作年龄较IgE阴性者大。结论变应原是引起儿童喘息的一个重要原因,尘螨是最常见的变应原。随着年龄增长,sIgE从食物性向吸入性移行。在反复喘息发作的患儿中,高IgE血症者喘息首发年龄较迟,这一部分患儿成为哮喘的高发人群。     

Relation between serum IL‐4, IL‐13 and IFN‐γ levels and recurrence of wheezing episodes in infants with acute bronchiolitis

Lower respiratory tract infections are the most important factors among various causes which trigger wheezing in the first year of life. The factors associated with episodic wheezing in children with acute bronchiolitis are still subjects of research. Infections, environmental factors, immunologic mechanisms are sorted as etiologic risk factors of episodic wheezing. We aimed to investigate the relationship between serum interleukin (IL)‐4, IL‐13 and γ‐interferon (IFN‐γ) levels and recurrence of wheezing episodes in infants with acute bronchiolitis. One hundred twenty infants between 3 and 36 months with acute bronchiolitis enrolled in the study. Personal histories, clinical and laboratory data of infants were recorded. The patients were followed for a year. Venous blood samples were obtained to determine serum IL‐4, IL‐13, and IFN‐γ levels during acute bronchiolitis episode. The number of wheezing episodes was significantly higher in infants with a positive family history of allergy. A statistically significant correlation was determined between serum IL‐13 levels of infants and number of wheezing episodes. High serum IL‐13 levels and a positive history of allergy may have important roles in the recurrence of acute bronchiolitis.     

Breastfeeding protects against adverse respiratory outcomes at 15 months of age

The relationship between breastfeeding, respiratory and other allergic disorders has been controversial. Our aim was to investigate the relationships between breastfeeding, respiratory outcomes, eczema and atopy at 15 months of age in a prospective birth cohort in New Zealand.
A total of 1105 children were enrolled at birth, and 1011 (91.2%) were followed up at 15 months. Logistic regression was used to model associations between breastfeeding duration and respiratory outcomes, eczema and atopy after adjusting for relevant confounding variables: ethnicity, socio-economic status, parity, body mass index, smoking in pregnancy, gender and respiratory infections in the first 3 months of life.
Breastfeeding was associated with a significant reduction in the risk of adverse respiratory outcomes at 15 months. After adjustment for confounders, each month of exclusive breastfeeding reduced the risk of doctor-diagnosed asthma by 20% (odds ratio 0.80, 95% confidence interval 0.71 to 0.90), wheezing by 12% (0.88, 0.82 to 0.94) and inhaler use by 14% (0.86, 0.78 to 0.93). Associations for both exclusive and additional breastfeeding durations, and respiratory outcomes remained independently significant when modelled simultaneously. Although independently associated with all respiratory outcomes, adjusting for parental history of allergic disease or maternal history of asthma did not alter our findings. Breastfeeding was not associated with eczema or atopy at 15 months.
In conclusion, there was a significant protective effect of breastfeeding on infant wheezing and other adverse respiratory outcomes that may be early indicators of asthma in New Zealand children.     

Mast cell activation and leukotriene secretion in wheezing infants. Relation to respiratory syncytial virus and outcome

The persistence of wheezing after early wheezing episodes in infancy may be related to the virus involved and to the type of inflammation during the initial wheezing. The role of mast cell activation and leukotriene secretion in wheezing, and the relation to outcome, is not known. Our objective was to study markers of mast cell activation and leukotriene secretion from wheezing infants, and the relation to respiratory syncytial virus (RSV) infection and persistent wheezing. Urinary 9alpha,11beta-PGF(2), a marker of mast cell activation, and urinary leukotriene E4 were measured in 106 infants hospitalized for wheezing during their first year of life. Results were related to the presence of RSV infection and the persistence of wheezing at follow-up 20 months later. Levels of 9alpha,11beta-PGF(2) were higher in infants positive for RSV than in those with RSV negative wheezing, but both groups had higher levels than controls. Leukotriene E4 levels were higher in wheezing infants than in controls. Urinary 9alpha,11beta-PGF(2) levels were higher in infants with transient compared with persistent wheezing. We found a positive correlation between 9alpha,11beta-PGF(2) and leukotriene E4, strongest in infants with RSV negative disease and in infants with persistent wheezing. The results suggest that mast cells play an important role in infant wheezing, and may be a major source of leukotriene secretion in these infants. Mast cell activation and leukotriene secretion were not associated with persistent wheezing.     

Vitamin A deficiency and wheezing

Background  

Vitamin A deficiency may increase the responsiveness of the respiratory tract and increase the risk of respiratory tract infection, resulting in airway obstruction and wheezing. This study aimed to investigate the relation between vitamin A deficiency and infant wheezing.     

婴幼儿喘息与呼吸道病毒感染及过敏的关系

目的探讨婴幼儿喘息与呼吸道病毒感染及过敏的关系。方法选择反复喘息(哮喘和喘息性支气管炎)患儿152例、毛细支气管炎(毛支)患儿191例、肺炎患儿101例,取鼻咽分泌物进行7种常见呼吸道病毒检测,同时取血筛查过敏原。结果3组患儿病毒检测总阳性率为60.4%,各组患儿病毒检测阳性率差异有显著性(P<0.01),但均以呼吸道合胞病毒(RSV)为主,其他病毒阳性率很低。所有患儿食物过敏阳性率为25.5%,吸入过敏原阳性率仅5.6%。3组患儿的过敏原阳性率差异有显著性(P<0.05或0.01),反复喘息组显著高于毛支组和肺炎组(P均<0.05),而后两组间差异无显著性。结论RSV是诱发婴幼儿喘息和喘息反复发作的主要病原;过敏是婴幼儿反复喘息发生的重要危险因素,而呼吸道合胞病毒感染的发生与患儿是否存在过敏无关。     

The Wheezy Child

ABSTRACT. Wheezing in association with viral respiratory tract infections occurs in 10-20 % of all infants and young children and usually indicates hyperreactive bronchi. Signs of airway hyperreactivity can usually be demonstrated many years after the child has stopped wheezing. This hyperreactivity is partly constitutional, but it may be further aggravated by viral infections in the respiratory tract. Similarly, allergic inflammation or long-term exposure to airway irritants may also cause or aggravate a state of hyperreactivity which may be expressed as a proneness to asthmatic reactions. As viral infections are among the most potent asthma-provoking factors known, the hyperreactivity does not need to be very pronounced before wheezing develops in the infant or young child, with its small-calibred airway. As long as wheezing only occurs sporadically and only in association with viral respiratory tract infections, the prognosis is usually excellent. However, recommendations regarding avoidance of potent allergens and airway irritants in the daily environment should be given to such families. Such advice is especially important for families with a proneness to atopic reactions or if wheezing begins to occur even during infection-free periods     

The wheezy child

Wheezing in association with viral respiratory tract infections occurs in 10-20% of all infants and young children and usually indicates hyperreactive bronchi. Signs of airway hyperreactivity can usually be demonstrated many years after the child has stopped wheezing. This hyperreactivity is partly constitutional, but it may be further aggravated by viral infections in the respiratory tract. Similarly, allergic inflammation or long-term exposure to airway irritants may also cause or aggravate a state of hyperreactivity which may be expressed as a proneness to asthmatic reactions. As viral infections are among the most potent asthma-provoking factors known, the hyperreactivity does not need to be very pronounced before wheezing develops in the infant or young child, with its small-calibred airway. As long as wheezing only occurs sporadically and only in association with viral respiratory tract infections, the prognosis is usually excellent. However, recommendations regarding avoidance of potent allergens and airway irritants in the daily environment should be given to such families. Such advice is especially important for families with a proneness to atopic reactions or if wheezing begins to occur even during infection-free periods.     

Association of higher adiposity and wheezing in infants with lower respiratory illnesses

Aim: The incidences of asthma and obesity have been steadily increasing over the past two decades, with several studies showing a relationship between these conditions. We investigated the influence of higher weight for height (WFH) Z‐score on wheezing in infants with lower respiratory tract infections (LRTI). Methods: We reviewed the medical charts of all infants younger than l year of age who were admitted with the first episode of LRTI between 2000 and 2008. Subjects were classified into six groups according to WFH Z‐score. Results: Wheezing was more frequent in infants with higher WFH Z‐scores. Especially, wheezing infants aged 3–6 months and 6–9 months had significantly higher WFH Z‐scores than had their non‐wheezing counterparts (p = 0.05 and p < 0.01 respectively). Multivariate logistic regression showed that age (OR = 0.76, p < 0.001), male gender (OR = 1.61, p = 0.005) and WFH Z‐score (OR = 1.12, p = 0.007) were independently associated with wheezing. Conclusion: In this study we could show that a higher WFH Z‐score was independently associated with wheezing in infancy. Attainment of appropriate weight for age may reduce the risk of wheezing in infants with respiratory diseases.