Sensitization characteristics of ragweed pollen in Beijing area / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the sensitization characteristics of ragweed pollen in patients with allergic rhinitis（AR） and（or） allergic asthma in Beijing area, and to provide basis for the prevention and treatment of ragweed pollen sensitized population. Methods:Patients with allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were retrospectively analyzed in this study. Skin prick test（SPT） was performed with ragweed pollen allergen reagents to compare different ages, genders and respiratory diseases allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results:A total of 9 727 patients were enrolled in the end. The total positive rate of ragweed pollen SPT was 45.50%（4 426/9 727）, the highest positive rate was 65.54% in 13-17 years old group; The positive rate of ragweed pollen SPT was 49.79% in allergic rhinitis combined with asthma patients, followed by 46.46% in allergic rhinitis patients, and the lowest rate was 19.42% in single allergic asthma patients. There were more females than males in both ragweed pollen sensitized and non-ragweed pollen sensitized groups（P<0.05）, and the proportion was higher in 30-39 years old than in other age groups（P<0.05）. Ragweed pollen sensitization was higher than non-ragweed pollen sensitization in the allergic rhinitis group（98.49% vs 94.76%, P<0.05）. Ragweed pollen with other summer and autumn pollen allergens in patients with positive SPT, the top three were Chenopodium pollen, Humulus pollen and Artemisia grandis pollen, with positive rates of 90.42%, 89.63% and 85.40%, respectively. Ragweed combined with other pollen sensitization accounted for 99.57%（4 407/4 426）. Allergic rhinitis was the main disease in patients sensitized with ragweed pollen alone or combined with other pollens, and there was no significant difference between the two groups（94.97% vs 98.50%, P>0.05）. Conclusion:Ragweed pollen is highly sensitized in Beijing area, single ragweed pollen sensitization is rare, often combined with multiple pollen sensitization, and allergic rhinitis is the main disease.

Comparative study on establishing an immune tolerance model for allergic conjunctivitis in mice with different methods / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To establish an immune tolerance model for allergic conjunctivitis in newborn mice with different methods and observe the impact of environmental factors on allergic conjunctivitis in early life.METHOD: A total of 50 Balb/c newborn mice were randomly divided into blank control group, ovalbumin(OVA)+subcutaneous injection group, OVA+nebulized inhalation group, OVA+gastric group, ragweed pollen(RW)+subcutaneous injection group, RW+nebulized inhalation group, RW+gastric group, house dust mite(HDM)+subcutaneous injection group, HDM+nebulized inhalation group, HDM+intragastric group(n=5 animals/group). Except for the blank control group, mice in each group were individually exposed to the corresponding antigens to induce immune tolerance early in life and stimulated with the corresponding antigens in adulthood. The ocular surface was visualized by anterior segment photography. The relative expression level of conjunctival RANTES and IL-17 mRNA was measured by RT-qPCR and serum IL-17 concentration was measured by ELISA.RESULTS: Compared with the blank control group, the relative expression level of conjunctiva IL-17 mRNA in RW+gastric group was the highest, and it was the lowest in RW+subcutaneous group(all P&#x003C;0.05). The relative expression level of conjunctiva RANTES mRNA was the highest in RW+gastric group(P&#x003C;0.001). Compared with the blank control group, the serum concentration of IL-17 was increased in all treatment groups except OVA+nebulizer group and RW+subcutaneous group(P&#x003C;0.05).CONCLUSION: The immune tolerance of allergic conjunctivitis induced by subcutaneous injection of antigen was the most suitable method in the early life of mice.

Allergenic Pollen Calendar in Korea Based on Probability Distribution Models and Up-to-Date Observations

PURPOSE: The pollen calendar is the simplest forecasting method for pollen concentrations. As pollen concentrations are liable to seasonal variations due to alterations in climate and land-use, it is necessary to update the pollen calendar using recent data. To attenuate the impact of considerable temporal and spatial variability in pollen concentrations on the pollen calendar, it is essential to employ a new methodology for its creation.METHODS: A pollen calendar was produced in Korea using data from recent observations, and a new method for creating the calendar was proposed, considering both risk levels and temporal resolution of pollen concentrations. A probability distribution was used for smoothing concentrations and determining risk levels. Airborne pollen grains were collected between 2007 and 2017 at 8 stations; 13 allergenic pollens, including those of alder, Japanese cedar, birch, hazelnut, oak, elm, pine, ginkgo, chestnut, grasses, ragweed, mugwort and Japanese hop, were identified from the collected grains.RESULTS: The concentrations of each pollen depend on locations and seasons due to large variability in species distribution and their environmental condition. In the descending order of concentration, pine, oak and Japanese hop pollens were found to be the most common in Korea. The pollen concentrations were high in spring and autumn, and those of oak and Japanese hop were probably the most common cause of allergy symptoms in spring and autumn, respectively. High Japanese cedar pollen counts were observed in Jeju, while moderate concentrations were in Jeonju, Gwangju and Busan.CONCLUSIONS: A new methodology for the creation of a pollen calendar was developed to attenuate the impact of large temporal and spatial variability in pollen concentrations. This revised calendar should be available to the public and allergic patients to prevent aggravation of pollen allergy.

Chamber and Field Studies demonstrate Differential Amb a 1 Contents in Common Ragweed Depending on CO₂ Levels

Although atmospheric carbon dioxide (CO₂) has no apparent direct effect on human health, it does have direct effects on plants. The present study evaluated the influence of increased CO₂ levels on the concentration of allergens from common ragweed pollen by setting up a chamber study to model future air conditions and a field study to evaluate current air conditions. For the chamber study, we established 20 ragweed plants in an open-top chamber under different CO₂ levels (380–400, 500–520, 600–620, and 1,000–1,100 parts per million [ppm]). For the field study, we established ragweed plants in rural (Pocheon, Gyeonggi-do; mean CO₂ 320±54.8 ppm) and urban (Gangnam, Seoul; mean CO₂ 440±78.5 ppm) locations. Seeds of the common ragweed (Ambrosia artemisiifolia) were obtained from Daejin University. The Amb a 1 protein content of pollen extracts was quantified using a double sandwich enzyme-linked immunosorbent assay. In our chamber study, the median concentration of Amb a 1 in pollen increased with increasing in CO₂ concentration (1.88 ng/µg in 380–400 ppm CO₂; 3.14 ng/µg in 500–520 ppm CO₂; 4.44 ng/µg in 600–620 ppm CO₂; and 5.36 ng/µg in 1,000–1,100 ppm CO₂). In our field study, we found no significantly different concentration of Amb a 1 between the pollen extracts at the Pocheon (mean±standard deviation, 1.63±0.3 ng/µg pollen in 320±54.8 ppm CO₂) and the Gangnam (2.04±0.7 ng/µg pollen in CO₂ in 440±78.5 ppm CO₂) locations, although the concentration of Amb a 1 was increased in the Gangnam than in the Pocheon locations. Our results suggest that future increases in CO₂ levels to more than 600 ppm will significantly elevate the Amb a 1 content in common ragweeds, although the current different CO₂ levels do not cause differences in the Amb a 1 content of ragweed pollen.

The Correlation between Increased Sensitization Rate to Weeds in Children and the Annual Increase in Weed Pollen in Korea / 소아알레르기및호흡기학회지

PURPOSE: Recently allergic diseases have gradually increased in schools and among preschool aged childhood. Pollen amount of weeds also, especially ragweed, were increased. We evaluated the increased pollen count of weed was associated with the sensitization rate to weed in childhood. METHODS: Airborne particles carrying allergens were collected daily from eight stations nationwide(Seoul, Guri, Cheongju, Daegu, Kwangju, Busan, Kangneung, and Jeju) by using 7 days-Burkard sampler(Burkard Manufacturing Co Ltd, Hertfordshire, UK), for 7 years in South Korea(July 1, 1997-June 30, 2004). They were counted and recorded along with the weather. Data was collected through pediatric patients with allergic symptoms, who visit the pediatrics allergy clinics and capable of allerfy skin test among hospitals that have pollen collecting centers. RESULTS: Airborne pollen has two peak seasons:May and September in Korea. There were the tree pollen seasons from the middle of February to late July, then followed the grasses and weed season from the middle of July to the end of October. Ragweed was one of the most common pollens of autumn in Korea. In skin prick tests, Mugwort was the highest sensitization rate(7.6 percent), followed by ragweed(7.1 percent), birch(6.1 percent), alder, grasses mix among the pollen extracts in Korean school aged children. Ragweed pollen counts have gradually increased since 2000. In the same period, sensitization rates for airborne pollen, especially weeds, in Korean children have increased annually(1999:4.4 percent, 2000:7.1 percent, 2001:7.4 percent, 2002:8.5 percent, 2003:7.7 percent). CONCLUSION: Sensitization rates for outdoor airborne pollens have increased in Korean children. These findings might result from the changes of life styles and living environments in Korea.

Antigenic relationship between mugwort and ragweed pollens by crossed immunoelectrophoresis

Mugwort and ragweed pollens have been considered as important respiratory allergens in Korea. These two pollens are abundant in the air of Seoul from August through October. Many ragweed-sensitive patients have shown concurrent sensitivities to mugwort pollen. However the antigenic relationship between these two pollens has not been clarified. To observe the cross-reactivity between them, we developed polyclonal anti-mugwort and anti-ragweed antibodies by immunization on New Zealand white rabbits, and performed crossed immunoelectrophoresis(CIE) with two pollen extracts. Five precipitation lines were formed by mugwort and anti-mugwort antibody. One precipitation line was formed by ragweed and anti-ragweed antibody. There was no reaction from mugwort and anti-ragweed antibody, and from ragweed and anti-mugwort antibody. These results indicate that there is no cross-antigenicity between mugwort and ragweed pollens.

Evaluation of effectiveness of antigen specific immunotherapy for patients with allergic rhinitis / 解放军医学杂志

Objective To evaluate the effectiveness of allergen specific immunotherapy (SIT) in the treatment of allergic rhinitis. Methods A total of 132 patients with seasonal ragweed allergic rhinitis were enrolled in this study. The patients were randomly divided into two groups. SIT group, in which 68 patients were treated with ragweed SIT for six months before July for 3 years. ST (symptomatic therapy) group, in which 64 patients were treated with ST during seasonal symptomatic period. The healthy control group included 40 subjects. The levels of serum total IgE (tIgE), specific IgE (sIgE), ECP, IgG and IL-4, IL-5, IFN-? were measured, and eosinophil numbers were counted. The symptom score, lung-function test and skin prick test were performed before and after the treatment. Results The elevated levels of tIgE, ECP, IL-4, IL-5 in the sera and eosinophil counts in peripheral blood of the patients were significantly reduced, whereas the levels of IgG and IFN-? were increased following SIT. The levels of serum sIgE were not changed in both SIT and ST groups. 30.88% of the patients were clinically cured, the effective rate was 41.18%, the improvement rate was 20.59% after SIT, and only in 7.39% of patients there was no clinical improvement. In 16.18% of patients there were mild side effects to SIT. In the ST group, there was on change in all the laboratory results and clinical symptoms, and 25% of the patients developed asthma. Conclusion SIT was able to improve the symptoms and laboratory results of the patients with allergic rhinitis. The results indicated that SIT may be an effective and safe therapy for patients with allergic rhinitis.