Allergenic pollen and pollen allergy in Europe

The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases.     

Tree pollen allergy

872 adult hay fever patients were investigated with skin tests, using 20 different tree pollen allergens, and Phadebas RAST, using eight different tree pollen allergens. Correlation between test results with the different allergens were studied employing the Spearman's correlation coefficient (Rho). Most combinations showed statistically significant correlations. The highest values of Rho (0.8-0.9) were found for pollen from combinations of trees belonging to the families Betulaceae, Corylaceae and Fagaceae (birch, alder, hazel, beech and oak). High values were also found between pollens from aspen and sallow (belonging to Salicaceae). With several of the trees a high degree of pollen cross sensitization was found, even with trees from a different plant family. Since most of the patients were allergic to birch pollen, some of the reactions to other pollens could be due to allergens shared by birch. To exclude this possibility, a separate analysis was performed for patients having no birch pollen allergy. Even in these patients evidence of cross sensitization was found. It is concluded that cross reactions are common among tree pollens and are most pronounced within botanical families.     

Rice pollen allergy in Taiwan

A panel of tests including intracutaneous skin testing (ST), radioallergosorbent test (RAST), immunoblotting and allergen-induced lymphoproliferation was done to study rice pollen allergy in asthmatic children and to characterize the allergens. Of the 312 asthmatic patients skin tested, 29 (9.3%) had positive reactions (wheal greater than or equal to 6 mm) to rice pollen extract at a concentration of 10(-5) g/mL and the remaining 283 (90.7%) were negative. While eight (34.8%) of the 23 ST-positive patients were also RAST-positive, RAST was negative in all 34 ST-negative patients and 20 normals. Immunoblotting revealed three major allergens, with molecular weights of 16 kD, 26 kD, and 32 kD, respectively. Interestingly, RAST-positive patients showed IgE responses to most allergens but only a few of them had IgG antibodies, while normal controls had stronger IgG responses to the same allergens, particularly to 32 kD, but none had IgE antibody. The preliminary results of rice pollen protein induced-lymphoproliferation were not informative; thus, rice pollen proteins do elicit a specific response in asthmatic children and normals, but its pathogenic role in bronchial asthma needs further study.     

Oral allergy syndrome to chicory associated with birch pollen allergy

BACKGROUND: A few cases of IgE-mediated chicory allergy with oral, cutaneous, and/or respiratory symptoms are reported. We present 4 patients with inhalant birch pollen allergy and oral allergy syndrome to chicory. IgE-binding proteins in chicory and cross-reactivity with birch pollen were studied. METHODS: Chicory extract was prepared and immunoblotting was used to study IgE reactivity and cross-reactions with birch pollen. RESULTS: The pattern of IgE binding to chicory was variable among the patients, with protein bands recognized at 18, 21, 40, 52 and 71 kD. Bet v 1-like proteins were detected in chicory by monoclonal antibody binding. Chicory-birch pollen cross-reactivity, as studied in 2 patients from whom enough serum was available, could be demonstrated but did not involve the Bet v 1 protein family. In one of these cases, a 51-kD protein of birch pollen was found to be responsible for cross-reactivity. CONCLUSIONS: Chicory should be added to the list of foods that can cross-react with birch pollen and cause the birch pollen-associated oral allergy syndrome.     

Currant allergy and the Rosaceae-grass pollen allergy syndrome: a case report.

BACKGROUND: Despite the increasing use of currants in culinary recipes, currant allergy has rarely been reported. OBJECTIVES: To study a case of currant allergy and to explore cross-reactivity between grass pollen and Rosaceae family fruit allergens. METHODS: Skin prick tests to pollen and skin prick-to-prick tests with currants and peach were performed. Specific IgE levels were determined using the CAP method. We prepared a protein extract of 0.1 mg/mL in phosphate-buffered saline using red currant in the presence of protease inhibitors. Immunoblot inhibition studies were performed to explore cross-reactivity between grass pollen and currant allergens. RESULTS: Skin prick test results were positive to Dactylis, arizonic, and olive pollens. Results of skin prick-to-prick tests with fresh red and black currants were negative and positive, respectively, to peach. The specific IgE level was 5.7 KU/L to red currant and 2.92 KU/L to peach (CAP). Western blot analysis with red currant extract revealed specific IgE protein bands of 37 and 26 kDa. Preincubation of sera with extracts from red currant and peach inhibited both IgE bands, and preincubation with Dactylis pollen inhibited the 37-kDa band only. CONCLUSIONS: We report a case of allergy to grass pollen with an oral allergy syndrome involving several fruits from 2 different families of the Rosidae subclass confirmed by in vitro tests. Inhibition studies demonstrated cross-reactivity between different fruits (currant and raspberry) from the Rosidae subclass and were incomplete with grass pollen allergens.     

艾蒿花粉诱导豚鼠过敏反应

目的：研究艾蒿花粉粗提物（MPE）和其主要成分之一artemisia vulgaris 1（Art V1）能否诱导豚鼠过敏反应,为艾蒿花粉过敏症研究建立动物模型。方法: 艾蒿花粉粗提物或Art V1混悬于佐剂氢氧化铝凝胶中,每间隔10 d致敏豚鼠1次,共4次,然后以艾蒿花粉粗提物或Art V1抗原滴鼻诱发鼻炎症状。气道高反应性(AHR)、炎症细胞和肺组织病理的观察于Art V1气雾攻击5 d后,以乙酰甲胆碱（Mch）气雾吸入激发AHR,测定气道阻力和动态肺顺应性,计数和分类计数支气管肺泡灌洗液（BALF）中的炎症细胞,观察肺组织病理学改变。 结果: Art V1组豚鼠在抗原激发下喷嚏次数和抓鼻次数显著增加,吸入Mch后气道阻力明显增加,动态肺顺应性明显降低,Mch气雾吸入可激发AHR;MPE组豚鼠喷嚏次数有所增加,气道反应性有所升高;两组BALF和病理切片均显示明显的嗜酸性粒细胞和中性粒细胞浸润。结论: 艾蒿花粉粗提物和其主要成分Art V1均能诱导豚鼠过敏反应,Art V1致敏效果明显优于艾蒿粗提物。该模型的建立有利于过敏性疾病机制和治疗新药的研究。     

Neonatal birch-pollen contact and subsequent allergy to birch pollen

It is shown by regression analysis that the risk of immediate hypersensitivity to birch pollen, as measured by a skin test, is positively correlated with the quantity of birch male flowers and the number of non-rainy days in the first birch flowering season (May) met in infancy. The risk is also dependent on the month of birth, with maximal risk associated with birth in Februarys–April. The results suggest that early pollen contacts, particularly during the first 6 months of life, increase the risk of pollen allergy for a period of 20 years. We estimate that elimination of early birch pollen contacts could have reduced the prevalence of immediate hypersensitivity to birch by 28% in our age group 0–19 years.     

Celery sensitivity: clinical and immunological correlations with pollen allergy

The authors studied twenty patients with celery allergy and concomitant hypersensitivity to certain pollens (mugwort, birch). The specific symptoms induced by eating celery were attacks of urticaria and angio oedema (seventeen out of twenty) respiratory complaints (eight out of twenty), systemic anaphylaxis with vascular collapse (three out of twenty). A strong association between clinical reactions to celery and mugwort sensitization, and to a lesser degree between celery allergy and birch pollen sensitization was established. Celery allergy is mediated by IgE antibodies and can be easily diagnosed by cutaneous tests using fresh material and/or by adequate RAST test. RAST inhibitions performed on individual sera suggest the existence of common antigens in celery and mugwort, and in celery and birch pollen. However, the exact nature of these common antigens has not yet been determined.     

Living in towers as risk factor of pollen allergy

BACKGROUND: The effects of fluctuations in pollen counts have important implications for health services. Little research on the clinical implications of the vertical distribution of pollen in allergy symptoms has been carried out. METHODS: We have investigated the allergic symptoms of a population of 17 171 patients coming from our health area (Valladolid, Spain) and living in the city and villages. We compared the prevalence of sensitization to different pollens: Graminae, trees and shrub in relation with the floor of the building where they were living. RESULTS: Relative risk of pollen sensitization (confidence index, CI 95%) was higher in patients who were living at high floors than in those patients who were living in lower floors or at street level, independently of rural or urban conditions The chi-square showed a lineal trend in this relationship in the case of sensitization to grass pollen: chi(2): 1794, P > 0.00001 CONCLUSIONS: On the basis of our local investigations, natural pollen sensitization appears to increase with height where the patient lives. This paper reports clinical results on the influence of vertical pollen distribution in pollen allergy.