News on Climate Change, Air Pollution, and Allergic Triggers of Asthma.

The rising frequency of obstructive respiratory diseases during recent years, in particular allergic asthma, can be partially explained by changes in the environment, with the increasing presence in the atmosphere of chemical triggers (particulate matter and gaseous components such as nitrogen dioxide and ozone) and biologic triggers (aeroallergens). In allergic individuals, aeroallergens stimulate airway sensitization and thus induce symptoms of bronchial asthma. Over the last 50 years, the earth's temperature has risen markedly, likely because of growing concentrations of anthropogenic greenhouse gas. Major atmospheric and climatic changes, including global warming induced by human activity, have a considerable impact on the biosphere and on the human environment. Urbanization and high levels of vehicle emissions induce symptoms of bronchial obstruction (in particular bronchial asthma), more so in people living in urban areas compared than in those who live in rural areas. Measures need to be taken to mitigate the future impact of climate change and global warming. However, while global emissions continue to rise, we must learn to adapt to climate variability.

Nasal filters in prevention of seasonal rhinitis induced by allergenic pollen grains. Open clinical study.

Nasal filters (Sanispira) might represent a novel approach in preventing exacerbations of symptoms of seasonal allergic rhinitis by reducing pollen access to nasal cavities. Female and male voluntary patients between the ages of 18 and 64 years living in Naples area and affected by allergic rhinitis were recruited in an open clinical study. All were allergic to Parietaria pollen as assessed by skin-prick and/or RAST test with or without associated sensitization to other pollens such as Gramineae and Olea europaea. A pollen count was also carried out from 10th April until 30th of June 2011. The results of our study show positive statistical differences between the scores of common nasal symptoms and the reduced use of antihistaminic drugs in patients using nasal filters in comparison to non users. Nasal filters constitute a useful mean to reduce symptoms of seasonal allergic rhinitis in patients suffering from pollen allergy.

Projections of the effects of climate change on allergic asthma: the contribution of aerobiology.

Climate change is unequivocal and represents a possible threat for patients affected by allergic conditions. It has already had an impact on living organisms, including plants and fungi with current scenarios projecting further effects by the end of the century. Over the last three decades, studies have shown changes in production, dispersion and allergen content of pollen and spores, which may be region- and species-specific. In addition, these changes may have been influenced by urban air pollutants interacting directly with pollen. Data suggest an increasing effect of aeroallergens on allergic patients over this period, which may also imply a greater likelihood of the development of an allergic respiratory disease in sensitized subjects and exacerbation of symptomatic patients. There are a number of limitations that make predictions uncertain, and further and specifically designed studies are needed to clarify current effects and future scenarios. We recommend: More stress on pollen/spore exposure in the diagnosis and treatment guidelines of respiratory and allergic diseases; collection of aerobiological data in a structured way at the European level; creation, promotion and support of multidisciplinary research teams in this area; lobbying the European Union and other funders to finance this research.

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.

Environmental risk factors and allergic bronchial asthma.

The prevalence of allergic respiratory diseases such as bronchial asthma has increased in recent years, especially in industrialized countries. A change in the genetic predisposition is an unlikely cause of the increase in allergic diseases because genetic changes in a population require several generations. Consequently, this increase may be explained by changes in environmental factors, including indoor and outdoor air pollution. Over the past two decades, there has been increasing interest in studies of air pollution and its effects on human health. Although the role played by outdoor pollutants in allergic sensitization of the airways has yet to be clarified, a body of evidence suggests that urbanization, with its high levels of vehicle emissions, and a westernized lifestyle are linked to the rising frequency of respiratory allergic diseases observed in most industrialized countries, and there is considerable evidence that asthmatic persons are at increased risk of developing asthma exacerbations with exposure to ozone, nitrogen dioxide, sulphur dioxide and inhalable particulate matter. However, it is not easy to evaluate the impact of air pollution on the timing of asthma exacerbations and on the prevalence of asthma in general. As concentrations of airborne allergens and air pollutants are frequently increased contemporaneously, an enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of allergic respiratory allergy and bronchial asthma. Pollinosis is frequently used to study the interrelationship between air pollution and respiratory allergy. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc) can affect both components (biological and chemical) of this interaction. By attaching to the surface of pollen grains and of plant-derived particles of paucimicronic size, pollutants could modify not only the morphology of these antigen-carrying agents but also their allergenic potential. In addition, by inducing airway inflammation, which increases airway permeability, pollutants overcome the mucosal barrier and could be able to "prime" allergen-induced responses. There are also observations that a thunderstorm occurring during pollen season can induce severe asthma attacks in pollinosis patients. After rupture by thunderstorm, pollen grains may release part of their cytoplasmic content, including inhalable, allergen-carrying paucimicronic particles.

General strategy for the management of bronchial asthma in pregnancy.

Epidemiological studies showed that bronchial asthma is one of the most common diseases which can complicate pregnancy (1-7%). In about 0.05-2% of the cases, asthma occurs as a life-threatening event. In the common medical practice a waiting strategy or, even, the complete refusal for drug therapies are frequently observed. This is justified by the fear of the possible adverse effects of drugs on developing fetus. On the contrary, several studies have demonstrated that severe and uncontrolled asthma may produce serious maternal and fetal complications, such as gestational hypertension and eclampsia, fetal hypoxemia and an increased risk of perinatal death. Therefore, all pregnant women suffering from bronchial asthma should be considered as potentially at high risk of complications and adequately treated. Since asthma is a chronic disease with acute exacerbations, a continuous treatment is mandatory to control symptoms, to prevent acute episodes and to reduce the degree of airway inflammation. The global strategy for asthma management in pregnancy includes five main topics: (1) objective evaluation of maternal/ fetal clinical conditions; (2) avoidance/control of triggering factors; (3) pharmacological treatment; (4) educational support; (5) psychological support. As far as drug therapy is concerned, the International Guidelines and Recommendations suggest that the general strategy does not differ significantly from management outside pregnancy. We herein review and discuss the available data and the criteria for the management of asthma in pregnant patients.

Outdoor air pollution, climatic changes and allergic bronchial asthma.

Both the prevalence and severity of respiratory allergic diseases such as bronchial asthma have increased in recent years. Among the factors implicated in this "epidemic" are indoor and outdoor airborne pollutants. Urbanisation with its high levels of vehicle emissions and Westernised lifestyle parallels the increase in respiratory allergy in most industrialised countries, and people who live in urban areas tend to be more affected by the disease than those of rural areas. In atopic subjects, exposure to air pollution increases airway responsiveness to aeroallergens. Pollen is a good model with which to study the interrelationship between air pollution and respiratory allergic diseases. Biological aerosols carrying antigenic proteins, such as pollen grains or plant-derived paucimicronic components, can produce allergic symptoms. By adhering to the surface of these airborne allergenic agents, air pollutants could modify their antigenic properties. Several factors influence this interaction, i.e., type of air pollutant, plant species, nutrient balance, climatic factors, degree of airway sensitisation and hyperresponsiveness of exposed subjects. However, the airway mucosal damage and the impaired mucociliary clearance induced by air pollution may facilitate the penetration and the access of inhaled allergens to the cells of the immune system, and so promote airway sensitisation. As a consequence, an enhanced immunoglobulin E-mediated response to aeroallergens and enhanced airway inflammation favoured by air pollution could account for the increasing prevalence of allergic respiratory diseases in urban areas.

The role of outdoor air pollution and climatic changes on the rising trends in respiratory allergy.

Evidence suggests that allergic respiratory diseases such as hay fever and bronchial asthma have become more common world-wide in the last two decades, and the reasons for this increase are still largely unknown. A major responsible factor could be outdoor air pollution, derived from cars and other vehicles. Studies have demonstrated that urbanization and high levels of vehicle emissions and westernized lifestyle is correlated with the increasing frequency of pollen-induced respiratory allergy. People who live in urban areas tend to be more affected by pollen-induced respiratory allergy than those from of rural areas. Pollen allergy has been one of the most frequent models used to study the interrelationship between air pollution and respiratory allergic diseases. Pollen grains or plant-derived paucimicronic components carry allergens that can produce allergic symptoms. They may also interact with air pollution (particulate matter, ozone) in producing these effects. There is evidence that air pollutants may promote airway sensitization by modulating the allergenicity of airborne allergens. Furthermore, airway mucosal damage and impaired mucociliary clearance induced by air pollution may facilitate the access of inhaled allergens to the cells of the immune system. In addition, vegetation reacts with air pollution and environmental conditions and influence the plant allergenicity. Several factors influence this interaction, including type of air pollutants, plant species, nutrient balance, climatic factors, degree of airway sensitization and hyperresponsiveness of exposed subjects.

Environmental risk factors (outdoor air pollution and climatic changes) and increased trend of respiratory allergy.

A wealth of evidence suggests that allergic respiratory diseases such as rhinosinusitis and bronchial asthma have become more common worldwide in recent years and a great deal of etiological and pathogenic research has been carried out to evaluate the possible causes of this increasing trend. There is also some evidence that increased atmospheric concentrations of pollutants such as ozone (O3), nitric oxides (NOx), respirable particulate (PM10) and volatile organic chemicals (VOC5), which result from increased use of liquid petroleum gas or kerosene, may be linked to the increased prevalence of allergic diseases which develop more frequently in urban areas of developed countries. Since bronchial asthma is a syndrome which can be aggravated by inhaled compounds, the effects of air pollutants on health have been the focus of attention. In fact, various studies have demonstrated that inhalation of air pollutants such as O3, nitrogen dioxide (NO2) and sulfur dioxide (SO2), either individually or in combination, can enhance the airway response to inhaled allergens in atopic subjects, thus inducing asthma exacerbations. Moreover, experimental studies have shown that diesel exhaust particulate causes respiratory symptoms and is able also to modulate the immune response by increasing IgE synthesis in predisposed animals and humans. There is also some evidence that air pollutants can interact with aeroallergens in the atmosphere and/or on human airways, potentiating their effects. In fact, by inducing airway inflammation which increases epithelial permeability, some pollutants overcome the mucosal barrier and lead to allergen-induced responses. However, air pollution and climatic changes should also have an indirect effect on allergic response by influencing quantitatively and qualitatively the pollen production by allergenic plants.

Outdoor air pollution in urban areas and allergic respiratory diseases.

Respiratory allergic diseases (rhinitis, rhinosinusitis, bronchial asthma and its equivalents) appear to be increasing in most countries, and subjects living in urban and industrialized areas are more likely to experience respiratory allergic symptoms than those living in rural areas. This increase has been linked, among various factors, to air pollution, which is now an important public health hazard. Laboratory studies confirm the epidemiological evidence that inhalation of some pollutants, either individually or in combination, adversely affect lung function in asthmatics. The most abundant air pollutants in urban areas with high levels of vehicle traffic are respirable particulate matter, nitrogen dioxide and ozone. While nitrogen dioxide does not exert consistent effects on lung function, ozone, respirable particulate matter and allergens impair lung function and lead to increased airway responsiveness and bronchial obstruction in predisposed subjects. However, besides acting as irritants, airborne pollutants can modulate the allergenicity of antigens carried by airborne particles. By attaching to the surface of pollen grains and of plant-derived paucimicronic particles, pollutants can modify the morphology of these antigen-carrying agents and after their allergenic potential. In addition, by inducing airway inflammation, which increases airway epithelial permeability, pollutants overcome the mucosal barrier and so facilitate the allergen-induced inflammatory responses. Moreover, air pollutants such as diesel exhaust emissions are thought to modulate the immune response by increasing immunoglobulin E synthesis, thus facilitating allergic sensitization in atopic subjects and the subsequent development of clinical respiratory symptoms.

Pollen-related allergy in Europe.

The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are having a relevant impact on our understanding of pollinosis and its distribution throughout Europe.

The perennial pattern of clinical symptoms in children monosensitized to Olea europaea pollen allergens in comparison with subjects with Parietaria and Gramineae pollinosis.

Because the pediatric age represents a good model to study the correlation between the exposure to allergens and development of respiratory allergy, we investigated the occurrence of a perennial type of symptomatology in children monosensitized to Olea europaea (O.e.) pollen allergens compared with subjects with monosensitization to Parietaria (P) and Gramineae (G) in order to confirm our previous observations in adults. We selected a group of 52 children with rhinitis and/or bronchial asthma and a SPT positivity only to pollens (30 to P, 15 to G, and 7 to O.e.). Using commercially available allergenic extracts and reagents, the following diagnostic procedures were performed: skin prick test (SPT), specific IgE assays (RAST), nonspecific bronchial provocation test (NsBPT) and specific nasal provocation test (sNPT), respectively, in patients with bronchial asthma and rhinitis. Pollen counts and a statistical analysis using Spearman's correlation test were also carried out. Six of seven children with monosensitization to O.e. allergens showed a perennial pattern of symptoms in comparison to 7 of 23 and 3 of 12, respectively, in subjects with P and G pollinosis. All patients with perennial nasal symptoms of O.e. group exhibited a late nasal response after sNPT. Although these findings on nasal response may partially explain the occurrence of a prolonged inflammation of the nose induced by O.e. allergens, we think that other possibilities could be investigated. In our opinion, further studies are necessary using better purified and standardized diagnostic materials and, moreover, a greater number of O.e. monosensitized children living in other geographical areas need to be examined for a comparison of our results with theirs.

Oral allergy syndrome (OAS) in pollinosis patients after eating pistachio nuts: two cases with two different patterns of onset.

We describe two uncommon cases of oral allergy syndrome (OAS) after eating pistachio nuts (p.n.) in subjects (a 54-year-old man and a 3-year-old girl) with exclusive skin prick test (SPT) positivity to Parietaria (P.) and pistachio nut (p.n.) allergens. Serologic P.- and p.n.-specific IgE determinations were also carried out. A double-blind, placebo-controlled food challenge (DBPCFC) was performed, for ethical reasons, only in the adult patient, but we observed a positive intraoral reaction only after slight scratching of the oral mucosa. Since this patient had put three whole p.n. with their shells into his mouth, breaking them with his teeth, before the onset of symptoms, we suggest that slight injury of the oral mucosa may enhance the local response. Preliminary results with SDS-PAGE and immunoblotting demonstrate the occurrence of a slight degree of cross-reactivity between these allergens, but further studies are necessary to obtain a definite conclusion.

Why are nasal and bronchial symptoms mostly perennial in patients with monosensitization to Olea europaea pollen allergens?

In the last few years interest in the clinical aspects of Olea europaea (O.e.) pollen allergy has increased. For many years we have observed in our geographical area a perennial pattern of clinical symptoms in subjects with monosensitization to O.e. allergens without any worsening during the olive pollen season. We tried to demonstrate the clinical relevance of O.e. sensitization in our patients and, moreover, to determine why this pattern is elicited. We selected a group of 26 patients with rhinitis and/or bronchial asthma and an immediate positive skin reaction only to O.e. pollen extract. Using commercially available extracts and reagents, the following diagnostic procedures were performed: Skin prick tests (SPT), specific O.e. IgE assays, nonspecific bronchial provocation tests (NsBPT) and specific nasal provocation tests (sNPT), respectively, in patients with bronchial asthma and rhinitis. Pollen counts and a statistical analysis using Spearman's correlation test were also carried out. 21 of 26 O.e. monosensitive patients showed perennial type of clinical symptoms without any particular worsening during olive pollination season. We found a high degree of statistical significance between the results of SPT/sNPT and serum specific IgE determination. Many patients exhibited a late response after sNPT. No definitive data were derived from our findings, even though the occurrence of many late reactions after sNPT could in part explain the perennial type of nasal symptoms. We would like to emphasize the necessity of better purification and standardization of diagnostic materials and, moreover, suggest further studies with a greater number of O.e. monosensitive patients living in different geographical areas.

Oleaceae pollinosis: a review.

In the Oleaceae family, the most allergenic pollen is produced by Olea europaea, the olive tree, which in the Mediterranean area has been recognized as one of the most important cause of seasonal respiratory allergy. The olive pollination season lasts from May to the end of June and sometimes causes severe symptoms (oculorhinitis and/or bronchial asthma). Olive pollinosis is quite rare in the form of monosensitization. Although adults are affected the most, olive sensitization can be recognized in children, too. However, it is not easy to be sure about the clinical relevance of allergic sensitization to olive, even in patients with positivity to this pollen, as results from allergological tests in vivo and/or in vitro, because positivity to Olea pollen is not equivalent to clinical responsibility, above all in patients without seasonal respiratory symptomatology. Studies on the allergenic content of O. europaea pollen are currently in progress. In Northern and Central Europe, where there are no olive trees, there are two commonly occurring genera of the Oleaceae family, namely Fraxinus and Ligustrum, but these have a low frequency of allergic sensitization. A fourth anemophilous member of the Oleaceae, Phillyrea, has a more regional distribution in some parts of the Mediterranean. Other nonanemophilous and usually not allergenic Oleaceae genera are Forsythia, Jasminum and Syringa.

Comparison between outdoor and indoor airborne allergenic activity.

BACKGROUND: Allergenic pollens are usually detected in outdoor air by using volumetric spore traps, which allow measurement of atmospheric concentration as pollen grains per m3 of air. The results of the pollen count are useful primarily for outdoor environments while most people spend most of the day indoors. OBJECTIVE: The purpose of our study was to compare outdoor pollen levels with allergenic activity measured both outdoors and indoors. METHODS: We used a Lanzoni spore trap to measure airborne Urticaceae pollen and filters collecting particles simultaneously indoors and outdoors and assayed each filter for Parietaria judaica allergenic activity. Samples were collected at the Allergological Service of the "A. Cardarelli" Hospital in Naples with the balcony open on some days and closed on others. Allergenic activity (ng/m3) was measured using the immunocapture RAST. RESULTS: With the balcony open there was no great difference between outdoor and indoor allergenic activity, but with the balcony closed there was a reduction of indoor allergenic activity of about one-third in comparison with outdoor allergenic activity. Statistical analysis (Pearson correlation test) indicated a significant correlation between outdoor allergen levels and indoor allergen levels with the balcony open (r = .4415, P < .05), but not with the balcony closed (r = .3160, P > .05); a significant correlation between outdoor pollen count and indoor allergen levels with the balcony open (r = .4809, P < .05), but not with the balcony closed (r = .3858, P > .05); and a highly significant correlation (r = .5225, P < .001) between outdoor pollen count and outdoor allergen levels. CONCLUSIONS: These data provide scientific evidence for the recommendation to hay fever patients to remain indoors during seasons with high levels of outdoor pollens.