Sensitization rates of airborne pollen and mold in children

Purpose

Aeroallergens are important causative factors of allergic diseases. Previous studies on aeroallergen sensitization rates investigated patients groups that had visited pediatric allergy clinics. In contrast, we investigated sensitization rates in a general population group of elementary school to teenage students in Incheon, Jeju, and Ulsan.

Methods

After obtaining parental consent, skin-prick tests were performed on 5,094 students between March and June 2010. Elementary school students were tested for 18 common aeroallergens, whereas middle and high school students were tested for 25 allergens. The 25 allergens included Dermatophagoides pteronyssinus, Dermatophagoides farinae, pollen (birch, alder, oak, Japanese cedar, pine, willow, elm, maple, Bermuda grass, timothy grass, rye grass, orchard grass, meadow grass, vernal grass, mugwort, Japanese hop, fat hen, ragweed, and plantain), and mold (Penicillatum, Aspergillus, Cladosporium, and Alternaria).

Results

The sensitization rates in descending order were 25.79% (D. pteronyssinus), 18.66% (D. farinae), 6.20% (mugwort), and 4.07% (willow) in Incheon; 33.35% (D. pteronyssinus), 24.78% (D. farinae), 15.36% (Japanese cedar), and 7.33% (Alternaria) in Jeju; and 32.79% (D. pteronyssinus), 30.27% (D. farinae), 10.13% (alder), and 8.68% (birch) in Ulsan. The dust mite allergen showed the highest sensitization rate among the 3 regions. The sensitization rate of tree pollen was the highest in Ulsan, whereas that of Alternaria was the highest in Jeju. The ragweed sensitization rates were 0.99% in Incheon, 1.07% in Jeju, and 0.81% in Ulsan.

Conclusion

The differences in sensitization rates were because of different regional environmental conditions and distinct surrounding biological species. Hence, subsequent nationwide studies are required.

The revised edition of korean calendar for allergenic pollens

The old calendar of pollens did not reflect current pollen distribution and concentrations that can be influenced by changes of weather and environment of each region in South Korea. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in eight regions nationwide between 1997 and 2009. The distribution of pollen was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) for 12 years between July 1, 1997 and June 30, 2009. Pollens were collected by using Burkard 7-day sampler (Burkard Manufacturing Co Ltd, UK). Pollens which were stained with Calberla's fuchsin staining solution were identified and counted. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. In Kangneung, birch appeared earlier, pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja and alder produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than ragweed. In Busan the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among all areas. In Kwangju, Oriental thuja and hazelnut appeared in early February. Japanese cedar showed the highest pollen concentration in March in Jeju. In conclusion, update information on pollen calendar in South Korea should be provided for allergic patients through the website to manage and prevent the pollinosis.

Cross-allergenicity of pollens from the Compositae family: Artemisia vulgaris, Dendranthema grandiflorum, and Taraxacum officinale

BACKGROUND

Chrysanthemum, dandelion, and mugwort belong to the Compositae (Asteraceae) family. Their cross-allergenicity has not yet been completely evaluated.

OBJECTIVE

To investigate the sensitization and cross-allergenicity of these 3 plants.

METHODS

We reviewed 6,497 respiratory allergic patients who underwent skin prick tests (SPTs) during the last 10 years (1995-2005) and analyzed the sensitization rates of the 3 pollens. We sorted this population by wheal size and selected the monosensitized or cosensitized patients. Their serum samples were used to evaluate specific IgE (sIgE) and cross-allergenicity of the 3 pollens by CAP, immunoblotting, and inhibition enzyme-linked immunosorbent assay (ELISA).

RESULTS

On SPTs, mugwort, chrysanthemum, and dandelion sensitized 13.4%, 10.0%, and 8.5% of the enrolled population, respectively, and 5.2% of the population was cosensitized to all 3 pollens. Some patients were monosensitized to 1 species (1.5% to chrysanthemum, 1.4% to dandelion, and 4.5% to mugwort). In inhibition ELISA that used a pooled serum sample cosensitized to all 3 pollens, mugwort inhibited sIgE bindings to chrysanthemum, dandelion, and mugwort up to 95%, 86%, and 96%, respectively. The 50% inhibitory allergen concentrations for sIgE to each of the 3 species were not different between solid-phase antigen and mugwort. The mugwort sIgE of this pooled serum was suppressed up to 74% and 27% by chrysanthemum and dandelion, respectively. The 50% inhibitory allergen concentrations of chrysanthemum and dandelion for mugwort sIgE were 0.3 and 57.0 microg/mL, respectively, whereas that of mugwort was 0.05 microg/mL. We found a patient who was truly monosensitized to dandelion.

CONCLUSION

Chrysanthemum and dandelion were frequently cosensitized with mugwort in the general population with respiratory allergic diseases. These 2 species also showed extensive cross-allergenicity with mugwort. True monosensitization to these 2 species was possible.

IgE immune response to Ginkgo biloba pollen

BACKGROUND

The ginkgo (Ginkgo biloba L.) continues to be planted as a shade tree in preference to other species in Seoul, Korea. The proportion of ginkgo to total shade trees was 43.2% in 1998, but the allergenic characteristics of ginkgo pollen has not been elucidated.

OBJECTIVES

This study was undertaken to obtain information regarding the skin reactivity rate to ginkgo pollen in a population of Korean subjects with respiratory allergy. Possible ginkgo pollen allergens and the cross-reactivity of ginkgo pollen with other prevalent pollens were also examined.

METHODS

Four hundred and forty-seven patients with asthma and/or allergic rhinitis were skin prick tested with extract of ginkgo pollen (1:20 wt/vol). Of these patients, positive skin responders (A/H ratio > or =2+) were selected for ELISA and immunoblot experiments.

RESULTS

A total of 21 patients (4.7%) showed skin reactivity (A/H ratio > or =2+) to ginkgo pollen in the skin prick test. They were also cosensitized to many other tree, grass, and weed pollens. Sixteen (76%) of the 21 positive skin responders showed specific IgE responses to ginkgo pollen in ELISA. In inhibitory ELISA, IgE binding to ginkgo pollen was inhibited by more than 80% by oak, ryegrass, mugwort, and ragweed; and 34% by hop Japanese; and 10% by rBet v 2 at 10 microg/mL. In immunoblot, 10 out of 21 sera (48%) reacted to the 15-kD protein of ginkgo pollen, 9 (43%) to 33-35 kD, and 8 (38%) to 36-38 kD. In inhibitory immunoblot, IgE binding to ginkgo pollen proteins was almost completely inhibited by oak, ryegrass, mugwort and ragweed, but only partially by hop Japanese and rBet v 2.

CONCLUSION

The skin reactivity rate to ginkgo pollen is approximately 4.7% in a population of Korean subjects with respiratory allergy. Since ginkgo pollen has a high cross-reactivity with other prevalent pollens, it could cause clinical symptoms during its pollen season by cross-reacting with the IgE produced in response to other pollens in patients sensitized to multiple pollens.