Prevalence of pollen‐induced allergic rhinitis with high pollen exposure in grasslands of northern China

Background

The aim of this study was to investigate the prevalence of epidemiologic and physician‐diagnosed pollen‐induced AR (PiAR) in the grasslands of northern China and to study the impact of the intensity and time of pollen exposure on PiAR prevalence.

Methods

A multistage, clustered and proportionately stratified random sampling with a field interviewer‐administered survey study was performed together with skin prick tests (SPT) and measurements of the daily pollen count.

Results

A total of 6043 subjects completed the study, with a proportion of 32.4% epidemiologic AR and 18.5% PiAR. The prevalence was higher in males than females (19.6% vs 17.4%, P = .024), but no difference between the two major residential and ethnic groups (Han and Mongolian) was observed. Subjects from urban areas showed higher prevalence of PiAR than rural areas (23.1% vs 14.0%, P < .001). Most PiAR patients were sensitized to two or more pollens (79.4%) with artemisia, chenopodium, and humulus scandens being the most common pollen types, which were similarly found as the top three sensitizing pollen allergens by SPT. There were significant regional differences in the prevalence of epidemiologic AR (from 18.6% to 52.9%) and PiAR (from 10.5% to 31.4%) among the six areas investigated. PiAR symptoms were positively associated with pollen counts, temperature, and precipitation (P < .05), but negatively with wind speed and pressure P < .05).

Conclusion

Pollen‐induced AR (PiAR) prevalence in the investigated region is extremely high due to high seasonal pollen exposure, which was influenced by local environmental and climate conditions.     

An occupational respiratory allergy caused by Sinapis alba pollen in olive farmers

BACKGROUND: Sinapis alba (white mustard) is a entomophilic species included in the Brassicaceae family. To date it has not been related to allergic sensitization or clinical respiratory disease. METHODS: Twelve olive orchard workers had a history of rhinitis and/or bronchial asthma that occurred during control weed management and/or harvest, from January to March. They underwent skin prick tests (SPT) with S. alba pollen extract and a standard battery of aeroallergens. Sinapis alba pollen extract was prepared for performing quantitative skin tests, enzyme allergosorbent test and nasal challenge test (NCT). A portable monitoring station and an urban volumetric Hirst-type spore trap were used for the aerobiological study. RESULTS: Eleven patients suffered from rhinitis and bronchial asthma and one had only from rhinitis. All patients were sensitized to S. alba pollen extract, and they showed a positive NCT response. In the urban aerobiologic monitoring station the amount of S. alba pollen only exceptionally reached peaks of 21 grains/m(3), whereas in the work environment peaks of 1801 grains/m(3) were detected between 15 February and 7 April. CONCLUSIONS: We demonstrate the existence of a new occupational allergen for olive farmers: S. alba pollen. We point out the importance of perform aerobiological sampling within the occupational environment for the detection and quantification of the allergenic source.     

不同颗粒物与致敏花粉联合暴露对中国仓鼠肺细胞的毒性

目的了解颗粒物与致敏花粉联合作用的细胞毒性。方法采用噻唑蓝(MTT)比色法检测12.5-200μg/ml发电厂燃煤飞灰、家用锅底灰、锅炉厂烟道灰、豚草花粉、梯牧草花粉和杨树花粉以及燃煤飞灰和三种花粉联合作用对中国仓鼠肺细胞(CHL)的毒性。结果三种颗粒物对CHL细胞生长抑制率为1.25%-19.62%,花粉对CHL细胞的生长抑制率为1.22%-46.96%,烯煤飞灰+花粉联合染毒组CHL细胞的生长抑制率为3.42%-30.23%。200μg/ml燃煤飞灰组CHL细胞抑制率为17.91%,豚草花粉、梯牧草花粉和杨树花粉组抑制率分别为15.87%、46.96%和19.98%,其混合物组CHL细胞抑制率为30.23%、21.26%和20.45%,燃煤飞灰+豚草花粉组抑制率高于其余两组(P<0.05)。结论颗粒物和花粉对CHL细胞毒性随染毒剂量增加而增加,燃煤飞灰与豚草花粉联合作用的细胞毒性高于单一受试物。     

Respiratory syncytial virus protects against the subsequent development of Japanese cedar pollen-induced allergic responses

Respiratory syncytial virus (RSV) infection has been hypothesized to be a risk factor for the development of allergy and asthma, but epidemiologic studies in humans still remain inconclusive. The association between RSV infection and allergic diseases may be dependent on atopic background and previous history of RSV infection. In this study, the influence of the timing of RSV infection on the development of Japanese cedar pollen (JCP)-induced allergic responses was examined. BALB/c mice were intranasally infected with RSV before or after sensitization to JCP. Production of cytokines in the culture fluid of lung parenchyma cells and the level of antigen-specific antibodies in the serum were determined. It became clear that JCP was a strong inducer for the elicitation of Th2-type responses, characterized by production of interleukin (IL)-4 and IL-5 in the lung and JCP-specific IgE antibody in the serum. RSV infection, however, suppressed JCP-induced allergic responses by decreasing the production of Th2-like cytokines and Th2-type antibodies. This phenomenon was observed more clearly in the groups that were infected with RSV, 2 weeks or 2 days before sensitization to JCP. The inhibitory mechanism of RSV infection seems to be due to RSV-induced Th1 type dominant environment, which down-regulated the Th2-type responses subsequently induced by allergen sensitization. On the other hand, JCP-inoculation altered RSV-induced immune responses to shift from Th1- to Th2-type dominance, by inhibiting RSV-induced Th1-like cytokine production. These data provide evidence that under a certain condition, RSV infection may play a protective role in JCP-induced allergic responses.     

SURVEY OF AIRBORNE POLLEN IN HUBEI PROVINCE OF CHINA

Objective To study the genera and seasonal distribution of airborne pollen in Hubei province of China, and its relationship with pollinosis.
Methods From November 2003 to October 2004, an airborne pollen investigation was performed in 16 chosen areas in 12 cities of Hubei province using gravity sedimentation technique. Meanwhile, univalent skin prick tests of pollens were performed and the invasion season was studied on 2 300 patients with pollinosis. Among them, 352 cases underwent the airway responsiveness measurements, and the correlation between airway responsiveness and results of pollen count was analyzed.
Results A total of 61 pollen genera were observed and 257 520 pollens were collected. The peak of airborne pollen distribution occurred in two seasons each year： spring （March and April） and autumn （from August to October）. The attack of pollinosis corresponded to the peak of pollen distribution. There was a significantly negative relationship between the provocation dose causing a 20% decrease of forced expiratory volume in one second （FEV1） from baseline and airborne pollen concentration （r= -0.6829, P 〈 0.05）.
Conclusion This study provides useful information for airborne pollen epidemiology of Hubei province, and it provides important insights to clinical prevention, diagnosis, and treatment of pollen-related allergic diseases.     

Climate change: allergens and allergic diseases

Climate change has been described as the biggest global health threat of the 21st century. The atmospheric concentrations of greenhouse gases, such as carbon dioxide, methane and nitrous oxide, have increased significantly since the start of the Industrial Era around 1750, with much of this increase occurring over just the last 50 years or so. This is resulting in warming of the climate system as well as changes in precipitation and weather and climate extremes. These changes in climate are having wide‐ranging impacts on the Earth’s physical, biological and human systems, including human health. It is these impacts of climate change on human health that are the focus of this paper, particularly the impacts on allergens and allergic diseases. Such impacts are particularly significant in many countries where the prevalence of such diseases is high and/or increasing. There is now compelling evidence that rising air temperatures and carbon dioxide concentrations are, in some plant species, resulting in increased pollen production and allergenicity and advancement and lengthening of the pollen season. Changes in extreme events, such as thunderstorms and tropical cyclones, will also have impacts on allergic diseases, with, for example, the flooding associated with tropical cyclones leading to proliferation of mould growth in damp homes. The article also considers a range of responses to these health threats, including greenhouse gas mitigation, and adaptation strategies, such as enhanced environmental monitoring and health surveillance and adequate planning for the future medical workforce.     

松花粉破壁前后显微形态和营养成分的研究

目的 :　通过对天然和破壁松花粉显微形态和营养成分的研究 ,了解花粉破壁的营养学意义。方法 :　使用低温高速气流干法粉碎技术破壁 ,分析天然和破壁松花粉的营养成分 ,用扫描电镜观察其显微形态的变化 ,研究破壁处理对天然花粉的影响。结果 :　观察到松花粉经高速气流粉碎破壁后 ,相当比例花粉颗粒的形态学改变是气囊从花粉主体颗粒上破碎、分离 ,花粉颗粒主体相对富集。花粉破壁后在容器中的流体特性丧失 ;破壁松花粉粘附性很强 ,已完全不能飞散。松花粉破壁后粗纤维、半纤维素、纤维素和木质素含量显著下降 ;总能量、总脂、淀粉含量明显提高 ;水溶性和脂溶性成分溶出量也大幅度增加。破壁松花粉总氨基酸含量除胱氨酸、精氨酸和甲硫氨酸外均高于天然松花粉 ;而游离氨基酸含量除胱氨酸、甘氨酸和甲硫氨酸外也都高于天然松花粉。松花粉破壁后可被乙醚提取的脂类成分大大增加。增幅达 7倍。结论 :　天然花粉经破壁处理后某些营养成分能充分释放。但因花粉所含脂类大多为不饱和脂肪酸 ,极易氧化 ,因此经破壁处理的花粉无法长时间贮存。