Allergenicity and cross-reactivity of Senecio pollen: identification of novel allergens using the immunoproteomics approach.

BACKGROUND: The genus Senecio is the largest genus of the family Asteraceae (Compositae). The allergenicity of Senecio has not been assessed previously. OBJECTIVE: The aim of this study was to investigate the allergens of Senecio jacobea pollen and to determine their immunological characteristics and clinical relevance. METHODS: Fifty patients with rhinoconjunctivitis and a positive skin prick test (SPT) to Senecio were recruited. The clinical relevance of this pollen was assessed by means of a nasal provocation test (NPT). Allergens were characterized by one-dimensional electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis and immunoblotting. Furthermore, characterization and identification of the allergens were performed by mass spectrometry (MS). In vitro inhibition tests were performed to evaluate cross-reactivity with other pollen. RESULTS: Three predominant allergens, both in the intensity of reaction and the frequency of recognition by human-allergic sera, were 59 (60%), 42 (50%) and 31 kDa (50%). The two-dimensional analysis allowed the identification of several allergens. One spot around 42 kDa was identified as a protein homologous to pectate lyase and three other spots were homologous to malate dehydrogenase by MS. S. jacobea proteins showed cross-reactivity with other proteins of the Asteraceae family and also with Parietaria judaica. This was demonstrated by immunoblotting and ELISA inhibition studies. CONCLUSION: S. jacobea constitute a newly discovered allergenic source. It shows cross-reactivity with other members of the Asteraceae plant family as well as with P. judaica.

Allergy to cypress pollen.

Although Cupressus sempervirens has been spread over southern Europe since antiquity, cypress pollen allergy has not been reported until 1945. In France, the very first case reports were published in 1962. Since then, the prevalence of cypress pollinosis seems to demonstrate an upward trend, concomitantly with the increased use of cypress trees as ornamental plants, as wind breaks and as hedges. Hyposensitization, using improved pollen extracts, is increasingly prescribed. Besides, prevention measures begin to be implemented. Such measures include avoidance of planting new cypress trees, especially near human populations' centres, trimming of cypress hedges before the pollination season and agronomical research for hypoallergenic trees. Altogether, such new developments in cypress allergy deserve an update review.

Environment and sensitization to cypress in Israel.

Cypresses are part of the Israeli landscape, as well as they are over most of the Mediterranian area. Pollen dispersal starts in January and peaks in March-April. Assessment of hay-fever patients showed a prevalence of 24%-32% (depending on the region) sensitization to Cypress (Cupressus sempervirens) pollen extracts. 13% of all those who are sensitive to Cypress were monosensitized. They are symptomatic from February till April, when 70% of them have rhinitis, 30% also asthma and 18% conjunctivitis. In the monosensitized patients, anti-cypress immunotherapy was successful.

Cypress pollen counts in Israel.

In accordance with the terms of the modern world, this presentation is based on the WWW, with a small change in interpretation: WWW stands for Who? When? and Where?

How to reduce air pollution by Cupressus pollen?

Cypress trees are among the most famous trees of the Mediterranean region. The origin of Cupressus sempervirens is apparently in the East Mediterranean. A nice description of the site of origin of Cupressus was provided by the Roman philosopher Plinius: "cypress trees sprout spontaneously on Mt. Ida on the island of Crete, whenever the soil there is disturbed". The aesthetic shape of the trees, the quality of their timber and their adaptation to harsh environmental conditions has attracted people. Certain varieties of the tree (e.g., var. Pyramidalis) were spread rapidly all over the Mediterranean and since the 16th century were introduced into the Western Hemisphere and other parts of the world. During historical times, Cupressus sempervirens was so widely used in the East Mediterranean countries that it reached the brink of extinction. Nowadays it is planted on a large scale as an ornamental plant as a windbreak and as a forest tree. Such plantations have various impacts on their environment, many positive ones, some negative ones, and some disastrous ones. This last aspect is where cypresses come in.

Allergic responses to pollen of ornamental plants: high incidence in the general atopic population and especially among flower growers.

BACKGROUND: The incidence of allergy to pollen of ornamental plants has not been deeply investigated, and its extent has remained obscure. Most of such studies have concentrated only on pollen of ornamental plants from the Asteraceae family (Compositae). In this study an attempt was made to clarify whether various other ornamental plants may also cause skin responses and allergic symptoms among allergic urban dwellers and among rural flower growers. METHODS: Two hundred ninety-two patients were referred for allergic evaluation by their primary physicians; 75 flower growers and 44 university students were evaluated. For all participants, a detailed health record was obtained, and skin prick tests (SPTs) were performed. Extracts for SPTs included commercial common airborne allergens and autochthonous pollen extracts of 11 species of plants belonging to the Asteraceae, Ranunculaceae, Liliaceae, Scrophulariaceae, and Genetianaceae families. RESULTS: Fifty-one of the 292 patients (17%) referred for allergic evaluation had positive SPT responses to pollen of various ornamental plants. A similar incidence was found among the students (23%). However, the incidence among flower growers was significantly higher, reaching 52%. Higher incidence (83%) of positive SPT responses to ornamental plants was found among flower growers also sensitive to the common allergens. All the tested plants, not only those belonging to the Asteraceae family, provoked positive SPT responses in all 3 groups of participants. None of the participants from the general population or the group of students reported exacerbation of allergic symptoms on exposure to the tested plants. In contrast, almost half of the flower growers (45%) described nasal, ocular, or respiratory symptoms associated with occupational exposure to the tested plants. Some 15% of the growers were eventually compelled to change their profession. CONCLUSIONS: The incidence of positive SPT responses to ornamental plants was 17% to 23% among the general public but 52% among flower growers. Thus the effects of ornamental plant pollen on atopic patients should be seriously contemplated.

Emergency room visits of asthmatic children, relation to air pollution, weather, and airborne allergens.

BACKGROUND: The worldwide increase in the incidence, prevalence, and severity of asthma may suggest that environmental factors play a role in these epidemiologic changes. OBJECTIVE: To examine the correlations between air pollutants, weather conditions, airborne allergens, and the incidence of emergency room (ER) visits of children with acute asthma attacks. DESIGN: One-year prospective study. Data of daily concentration of air pollutants, weather conditions, and selective airborne allergens were collected and compared with the number of ER visits of asthmatic children. SUBJECTS: 1076 asthmatic children (aged 1 to 18 years) who presented at the Pediatric ER between January 1 and December 31, 1993. RESULTS: Correlations between fluctuations in ER visits of asthmatic children and various environmental parameters were more relevant for weekly than for daily values. Emergency room visits correlated positively with concentrations of NOx, SO2 and with high barometric pressure; and negatively with O3 concentration and minimal and maximal temperature. There were no significant correlations with concentrations of particulates, humidity, or airborne pollen and spores. An exceptionally high incidence of ER visits of asthmatic children was observed during September. This peak coincided with the beginning of the school year and the Jewish holidays. The correlations between ER visits and the environmental factors increased significantly when the September peak was excluded, revealing that 61% of the variance in ER visits was explained by NOx, SO2, and 03 concentrations, 46% by weather parameters, 66% by NOx, SO2 and barometric pressure, and 69% by the combination of air pollutants and weather parameters. CONCLUSION: The major factors found to be associated with ER visits of asthmatic children were high NOx, high SO2, and high barometric pressure. Negative correlation was found between ER visits of asthmatic children and ozone concentrations. The particularly high number of ER visits at the beginning of the school year and the Jewish holidays was probably associated with an increase in the number of viral infections and/or emotional stress.

The 'traveling salesman problem': a new approach for identification of differences among pollen allergens.

BACKGROUND: It is not easy to identify the specific plant species that causes an allergic response in a certain patient at a certain time. This is further complicated by the fact that closely related plant species cause similar allergic responses. A novel mathematical technique is used for analysis of skin responses of a large number of patients to several groups of allergens for improvement of the understanding of their similarity or dissimilarity and their status regarding cross-reactivity. METHODS: The responses of 153 atopic patients to 42 different pollen extracts were tested by skin prick tests. Among the responses of patients to various extracts, a measure of dissimilarity was introduced and calculated for all pairs of allergens. A matrix-structuring technique, based on a solution of the 'Travelling Salesman Problem', was used for clustering of the investigated allergens into groups according to patients' responses. The discrimination among clusters was confirmed by statistical analysis. RESULTS: Sub groups can be discerned even among allergens of closely related plants, i.e. allergens that are usually regarded as fully cross-reactive. A few such cases are demonstrated for various cultivars of olives and pecans and for various sources of date palms, turf grasses, three wild chenopods and an amaranth. CONCLUSION: The usefulness of the proposed approach for the understanding of similarity and dissimilarity among various pollen allergens is demonstrated.

Allergenicity of the pollen of Pistacia.

Differences in IgE binding and skin responses to pollen extracts of four species of Pistacia, and some immunochemical characteristics of this pollen were investigated. The incidence of positive SPT among atopic patients varied between 31.5% to the pollen extracts of P. vera and 24.6% to P. palaestina. The antigens are located on the exine of the grains as well as in their cytoplasm. Some of the antigens are common to all four species, whereas others seem to be specific. Cross-reactivity was found among the four species of Pistacia and between them and Schinus terebintifolious. Five conspicuous IgE-binding bands were observed in the immunoblots of the four examined species, the bands of 49, 57, 64, 68, and 79 kDa. The 36-37-kDa band of P. lentiscus and the 60- and 84-kDa bands of P. atlantica and P. vera were also noticeable. As the flowering seasons of Pistacia and Schinus do not overlap, the patients are exposed to such pollen for more than 4 months a year. Apparently, Pistacia pollen is a major source of allergy.

Antigenicity of the pollen proteins of various cultivars of Olea europaea.

The incidence of positive skin test responses among atopic subjects with suspected respiratory allergy was investigated with commercial and autochthonous pollen extracts of various cultivars of Olea europaea. Pollen was collected from olive trees of well-defined cultivars, extracted, and separated by SDS-PAGE. Immunoblots were used to identify the various IgE-binding proteins of the pollen extracts of the various cultivars. The results revealed six predominant IgE-binding bands, some of which appear in all the cultivars examined. The 18-20-kDa band (Ole e 1) appeared in only eight of the cultivars, but not in the nine others. The presence of specific IgE-binding bands in the various pollen extracts and their correlation with the incidence of positive skin tests are discussed.

Hypersensitivity to pollen of Olea europaea in Israel.

The incidence of skin-tested sensitivity to olive pollen allergens among subjects with suspected atopic respiratory allergy was investigated in various populations of Israelis. This incidence was correlated with the olive cultivars, with the abundance of trees in the patient's neighborhoods, and with the history of exposure of the studied populations to olive pollen. Positive skin reactions to olive pollen, among atopic patients of the Jewish population, is rather high where olive trees are abundant (66%), and lower (29%) where trees are scarce (P < 0.003). Sensitization was significantly lower (P < 0.003) among a population of Israeli atopic Arabs (16%), though these Arabs have lived in an olive-rich area for several generations.

[Correlation between exposure to allergenic pollens and allergic manifestations].

Due to increase in allergic morbidity, better understanding of the relationships between environmental parameters and clinical responses of patients is needed. Serious analysis of such correlations requires examination of an entire population. So far there has been no study in Israel that examined an entire population in order to establish the distribution of inhalant allergens, the prevalence of skin hypersensitivity and allergic clinical morbidity. To examine these parameters we studied the population of Kibbutz Netzer Sereni, a rural community exposed to large amounts of various pollen allergens. Of the 505 members aged 4-70 years, 395 (78.2%) responded. Air sampling, once a month throughout the year, identified the most prevalent inhaled allergens and measured amounts. Allergic profiles were evaluated using prick tests with allergenic extracts, clinical questionnaires and medical records. The most prevalent allergenic pollens in the air were pecan, olive, cypress and palm trees, grasses and weeds such as English plantain, sagebrush, pigweed and lamb's quarters. Over 45% of 395 participants were atopic to 1 or more of the 27 allergenic extracts. The most prevalent causes of atopy were the house dust mite (28.9%), sagebrush (16.5%), grasses (18.2%), pecan (13.2%) and cypress (11.1%). Over 50% of atopic residents were symptomatic, while 22.9% of those non-atopic reported symptoms that could be attributed to allergy. This investigation provides solid data for the prevalence of atopy and allergy in the region of this kibbutz.

Allergy to olive pollen: T-cell response from olive allergic patients is restricted by DR7-DQ2 antigens.

BACKGROUND: We have recently described the association between the IgE antibody response to Ole e I (the major antigen from olive tree pollen) and the DR7-DQ2 haplotype in a Spanish population. OBJECTIVE AND METHODS: Due to the linkage disequilibrium between DR7 and DQ2, and thus the difficult distinction between the role of these two antigens in the T-cell activation response, we decided to solve this question by two approaches: 1. The study of another ethnic group, individuals of Arabic origin, with a presumably distinct disequilibrium linkage between DR and DQ antigens. Genomic DNA typing was performed in 46 subjects (allergic and non-allergic) by Restriction Fragment Length Polymorphism (RFLP) and results showed that patients with specific IgE antibodies alpha-Ole e I, were DR7 and/or DQ2. These data show a similar restriction pattern to those previously described for Spanish patients. The phenotypic frequency of DR7 antigen is significantly greater than in the non-allergic population, with a corrected P (Pc) value of 0.03. 2. The analysis of the genetic requirements of Ole e I response, using T-cell lines specific for this antigen. This was first carried out by blocking the proliferative response of these T-cell lines with specific anti-human HLA class II antibodies and then testing the genetic restriction of this response using a panel of histocompatible and histoincompatible Antigen Presenting Cells (APCs). Both experiments corroborate the hypothesis that DR7 and DQ2 are implicated in the recognition of Ole e I.

The importance of the pecan tree pollen in allergic manifestations.

BACKGROUND: Pecan tree pollen is considered to be highly allergenic. However, no specific scientific data about its role in causing allergic diseases are available. OBJECTIVE: To study the role of pecan tree pollen in the development of allergy. METHODS: The presence of pecan tree pollen was determined by weekly and monthly counting of airborne grains. The incidence of pecan tree pollen atopy and clinical manifestations were studied in 395 participants, aged 4-70 years, who comprised 78.2% of the whole eligible population of a rural community. The participants were skin tested for different extracts of allergens, completed detailed questionnaires, and their medical files were evaluated. RESULTS: During May, pecan tree pollen grains comprised 70% of the total airborne grains. A positive skin-prick test (SPT) to pecan was shown by 46 (11.6%) participants, constituting 25.4% of the atopic population. Of those who were found atopic to one or more allergens 50.3% had symptoms, whereas the parallel figure for those atopic to pecan pollen was 76.1% (P < 0.005); 58.7% of the pecan atopic participants had hay fever, 43.5% had asthma, and 31.5% had both hay fever and asthma. Among pecan atopic participants the incidence of hay fever increased with age (P = 0.05), while the incidence of bronchial asthma, as a sole manifestation of allergy, decreased in the > 17-year-old age group (P < 0.01). Of the pecan atopics 65.2% had clinical symptoms coinciding only with the pecan pollen season and an additional 10.9% had perennial symptoms. CONCLUSION: Pecan tree releases highly allergenic pollen grains, which are correlated to the incidence of hay fever in the exposed population. The contribution of pecan tree pollen to the symptoms was highly significant after discounting olive and cypress trees that also pollinate in the spring. In children, the pecan tree constitutes a possible etiologic agent for the development of asthma.

Podocarpus gracilior and Callitris verrucosa--newly identified allergens that crossreact with Cupressus sempervirens.

Thirty-six symptomatic patients, with positive skin reactions to Cupressus sempervirens pollen extract were skin-tested with pollen extracts of Podocarpus gracilior and Callitris verrucosa, of these 17 (47%) had positive responses to P. gracilior, nine (25%) to C. verrucosa, and six (17%) to both. None of the non-atopic healthy controls had positive reactions to either of the extracts. Radioallergosorbent test (RAST)-inhibition studies were performed with pooled sera from three patients. Fifty per cent inhibition was obtained with 11 micrograms protein of C. sempervirens, 54 micrograms of P. gracilior, and 71 micrograms of C. verrucosa; however, when pollen extract of Olea europaea, an unrelated allergen, was tested, 265 micrograms protein were needed to obtain 50% inhibition. One-dimension sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of pollen extracts from the three species revealed that they had several very similar protein bands. Using Western blot analysis, several closely related IgE binding proteins were identified in the three species. It was concluded that the pollen grains of P. gracilior and of C. verrucosa are potentially allergenic. The presence of common allergenic proteins indicate partial crossreactivity with C. sempervirens.

Sensitivity to olea Europaea pollen in different populations in Israel.

Sensitivity to olive pollen was studied (by skin tests) in different Israeli populations suffering from respiratory allergies. The results were compared with aerobiological data, in order to correlate amount of exposure to prevalence of sensitization. It was found that in the Jewish population, sensitivity to olive pollen developed in direct proportion with the number of olive trees in the settlement: 66% where trees density is high, 29% where it is low. In the Arab population however, possibly genetically determined, the sensitization to olive pollen was low (only 14%) even though the density of trees is high.