Atmospheric pollen grains and spores in relation to allergy. II

Isolating the species element in grass pollen allergy: A review

Grass pollen is a leading cause of allergy in many countries, particularly Europe. Although many elements of grass pollen production and dispersal are quite well researched, gaps still remain around the grass species that are predominant in the air and which of those are most likely to trigger allergy. In this comprehensive review we isolate the species aspect in grass pollen allergy by exploring the interdisciplinary interdependencies between plant ecology, public health, aerobiology, reproductive phenology and molecular ecology. We further identify current research gaps and provide open ended questions and recommendations for future research in an effort to focus the research community to develop novel strategies to combat grass pollen allergy. We emphasise the role of separating temperate and subtropical grasses, identified through divergence in evolutionary history, climate adaptations and flowering times. However, allergen cross-reactivity and the degree of IgE connectivity in sufferers between the two groups remains an area of active research. The importance of future research to identify allergen homology through biomolecular similarity and the connection to species taxonomy and practical implications of this to allergenicity is further emphasised. We also discuss the relevance of eDNA and molecular ecological techniques (DNA metabarcoding, qPCR and ELISA) as important tools in quantifying the connection between the biosphere with the atmosphere. By gaining more understanding of the connection between species-specific atmospheric eDNA and flowering phenology we will further elucidate the importance of species in releasing grass pollen and allergens to the atmosphere and their individual role in grass pollen allergy.

Forecasting methodologies for Ganoderma spore concentration using combined statistical approaches and model evaluations

High concentration levels of Ganoderma spp. spores were observed in Worcester, UK, during 2006-2010. These basidiospores are known to cause sensitization due to the allergen content and their small dimensions. This enables them to penetrate the lower part of the respiratory tract in humans. Establishment of a link between occurring symptoms of sensitization to Ganoderma spp. and other basidiospores is challenging due to lack of information regarding spore concentration in the air. Hence, aerobiological monitoring should be conducted, and if possible extended with the construction of forecast models. Daily mean concentration of allergenic Ganoderma spp. spores in the atmosphere of Worcester was measured using 7-day volumetric spore sampler through five consecutive years. The relationships between the presence of spores in the air and the weather parameters were examined. Forecast models were constructed for Ganoderma spp. spores using advanced statistical techniques, i.e. multivariate regression trees and artificial neural networks. Dew point temperature along with maximum temperature was the most important factor influencing the presence of spores in the air of Worcester. Based on these two major factors and several others of lesser importance, thresholds for certain levels of fungal spore concentration, i.e. low (0-49 s m(-3)), moderate (50-99 s m(-3)), high (100-149 s m(-3)) and very high (150 < n s m(-3)), could be designated. Despite some deviation in results obtained by artificial neural networks, authors have achieved a forecasting model, which was accurate (correlation between observed and predicted values varied from r s = 0.57 to r s = 0.68).

Grass pollen allergy in children and adolescents-symptoms, health related quality of life and the value of pollen prognosis

INTRODUCTION

An association between pollen count (Poaceae) and symptoms is well known, but to a lesser degree the importance of priming and lag effects. Also, threshold levels for changes in symptom severity need to be validated. The present study aims to investigate the relationship between pollen counts, symptoms and health related quality of life (HRQL), and to validate thresholds levels, useful in public pollen warnings.

MATERIAL AND METHODS

Children aged 7-18 with grass pollen allergy filled out a symptom diary during the pollen season for nose, eyes and lung symptoms, as well as a HRQL questionnaire every week. Pollen counts were monitored using a volumetric spore trap.

RESULTS

89 (91%) of the included 98 children completed the study. There was a clear association between pollen count, symptom severity and HRQL during the whole pollen season, but no difference in this respect between early and late pollen season. There was a lag effect of 1-3 days after pollen exposure except for lung symptoms. We found only two threshold levels, at 30 and 80 pollen grains/m(3) for the total symptom score, not three as is used today. The nose and eyes reacted to low doses, but for the lung symptoms, symptom strength did hardly change until 50 pollen grains/m(3).

CONCLUSION

Grass pollen has an effect on symptoms and HRQL, lasting up to 5 days after exposure. Symptoms from the lungs appear to have higher threshold levels than the eyes and the nose. Overall symptom severity does not appear to change during the course of season. Threshold levels need to be revised. We suggest a traffic light model for public pollen warnings directed to children, where green signifies "no problem", yellow signifies "can be problems, especially if you are highly sensitive" and red signifies "alert - take action".

Aero-allergens in canine atopic dermatitis in southeastern Australia based on 1000 intradermal skin tests

OBJECTIVE

To determine the most relevant aero-allergens involved in canine atopic dermatitis in southeastern Australia and provide information about these aero-allergens to the general practitioner.

PROCEDURE

Dogs presented to the Animal Skin & Allergy Clinic with history and clinical signs of atopic dermatitis were injected intradermally with 38 different allergens and negative and positive control. Intradermal skin tests in 1000 dogs were retrospectively evaluated.

RESULTS

One third of all patients reacted to the house dust mite Dermatophagoides farinae. Allergens reacting in more than 15% of the patients were wheat (Triticum aestivum), sweet vernal (Anthoxanthum odoratum), English couch (Agropyron repens), yellow dock (Rumex crispus), Mexican tea (Chenopodium ambrosioides), plantain (Plantago lanceolata), melaleuca (Melaleuca quinquenervia) and peppercorn (Schimus spp).

CONCLUSION

House dust mites are the most common allergens in canine atopic dermatitis in southeastern Australia and D farinae is involved most frequently. However, a number of grass, weed and tree pollens also are involved regularly.

Abundance of airborne Penicillium CFU in relation to urbanization in Mexico City

Air was sampled simultaneously at three localities in Mexico City differing in urbanization index and air pollution level on 22 days during a period covering both dry and rainy seasons. An Andersen two-stage microbial sampler was used for 15 min at 28 liters min-1 to isolate culturable fungi on malt extract agar. After exposure, plates were incubated at 25 degrees C for 48 to 72 h before colonies were counted and identified to give concentrations of total fungal spores and of Penicillium spp., expressed as CFU per cubic meter of air. Total fungi numbered 91 to 602 CFU m-3 in Tlalpan Borough (southern area), 40 to 264 CFU m-3 in Cuauhtémoc Borough (downtown), and 26 to 495 CFU m-3 in Gustavo A. Madero Borough (northern area). Although Penicillium spp. were the second most frequently isolated fungal genus, concentrations were small, with a maximum of only 133 CFU m-3. Twice as many colonies were isolated in the southern area, with an urbanization index of 0.25 (arithmetic mean, 41 CFU m-3), as at other sampling stations with greater urbanization indices (arithmetic means, 19 and 20 CFU m-3). In the downtown area, with an urbanization index of 1.0, Penicillium spp. were more numerous than any other genus and formed 25% of the total fungal count compared with 14 and 17% in the other areas. Concentrations of airborne Penicillium spp. did not differ significantly between rainy and dry seasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory function in greenhouse workers

Respiratory findings were studied in a group of 135 female and 32 male workers employed in greenhouses. In addition 51 women and 30 men were studied as a control group. Exposed women had significantly higher prevalences of chronic cough, dyspnea, chest tightness, and rhinitis (P < 0.01) than the controls. Among the men, only rhinitis was more prevalent in greenhouse workers (P < 0.01) than in controls. Smokers had higher prevalences of all chronic respiratory symptoms than nonsmokers, but the differences were statistically significant only for chronic cough and rhinitis in women and for chronic phlegm in men. There was a high prevalence of acute symptoms during work. A large number of greenhouse workers complained of skin reactions to plants and pesticides (women: 37.8%; men: 34.4%). Workers had significantly lower mean ventilatory capacity measurements (except in the case of forced vital capacity) when compared to standard predicted values. Smokers and nonsmokers had similar values of lung function expressed as percentages of the predicted values. Greenhouse workers exposed for more than 10 years had a significantly lower FEF25, measured as a percentage of the predicted value, than workers exposed for less than 10 years. Our data indicate that occupational exposure to greenhouses may be associated with the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.

Outdoor airborne dermatophytes and related fungi: a survey in Turin (Italy)

Aerial dispersal of propagules, an important mechanism of fungal spread, has not been sufficiently studied for skin-infecting fungi. Over a period of one year, we have monitored the distribution of dermatophytes in the air of Turin. We have also examined the related aleurioconidic and arthroconidic fungi, which share physiological and morphological characters with dermatophytes and are sometimes considered to cause similar infections. A viable volumetric collector was used. Samples were taken each month; each sample collected 9.6 m3 of air. The medium was Dermasel agar supplemented with cycloheximide and chloramphenicol. Thirty-two species were isolated, within the genera Aphanoascus, Arthrographis, Chrysosporium, Geomyces, Gymnoascus, Malbranchea, Myceliophthora, Myxotrichum, Ovadendron, Trichophyton. The total mycoflora load obtained was rather low throughout the year and particularly in the hottest months. Apart from T. rubrum and T. mentagrophytes, which are dermatophytes very frequently encountered in Turin, many of the species detected have known pathogenic potential and/or keratinolytic activity.

Indoor moulds and asthma

SEVENTY-TWO ASTHMATIC patients aged 15 to 60 years were identified in a general practice. Together with 72 controls, matched for age and sex, they were investigated for evidence of allergy to moulds. Positive skin tests (weal at least 3mm greater in diameter than for saline control) to any of five moulds occurred in nine asthmatics and one control. Using RAST assay, IgE antibodies to any of four moulds were found in 38 asthmatics and 7 controls. Visible moulds were reported in the homes of 19 asthmatics (26%) and controls (12.5%). Penicillium was the mould most commonly found in the home and to which antibodies most often occurred, especially in the houses with mould. Exposure to indoor mould, especially Penicil lium, may be a contributory factor to the disease in some asthmatic patients.

Volumetric aerobiological survey of conidial fungi in the North-East Netherlands. II. Comparison of aerobiological data and skin tests with mould extracts in an asthmatic population

A study was undertaken to see whether the principal airborne fungi in the North-East Netherlands were also found to be the most reactive in skin testing. Atmospheric samples were taken weekly with the Andersen sampler, from April 1981, up to and including, June 1983. At the same time skin tests of 833 patients referred to the outpatient Departments of Pulmonology and Allergology, because of recurrent bronchial obstructive complaints and a suspected allergy, were studied for strongly positive skin reactivity to fungi. 4.6% of the patients reacted with a wheal of 10 mm diameter or more to one or more of the tested fungi. Almost three-quarters of the airborne fungal "flora" was composed of seven genera, namely (in order of occurrence): Cladosporium (42.6%), Botrytis (8.6%), Yeasts (7%), Penicillium (5.8%), Basidiomycetes (5.7%), Aspergillus (3.7%), and Alternaria (0.9%). In skin-testing, however, a different order of occurrence existed: namely: Beauveria (6.8%), Botrytis (6.1%), Aspergillus (4.7%), Mucor (3.8%), Epicoccum (3%), Cladosporium (2.3%), and Alternaria (1.1%). It is concluded that the most prevailing airborne moulds are not necessarily the most potent allergens, at least in skin testing. Aspergillus and Botrytis showed a high sensitization rate, while Cladosporium and Alternaria did not. Botrytis deserves further study because of its frequent airborne occurrence and marked allergenic properties.

Volumetric aerobiological survey of conidial fungi in the North-East Netherlands. I. Seasonal patterns and the influence of metereological variables

In order to obtain actual data about the qualitative and quantitative occurrence of airborne fungi in The Netherlands, a viable-volumetric sample survey with the Andersen sampler was undertaken. From April 1981 to the end of June 1983, one day a week samples were taken on the unobstructed rooftop of a hospital in the N-E Netherlands. An average of 268 Colony Forming Units (CFU), per sample, per cubic metre of air were found. Almost three-quarters of the total catch consisted of seven genera, Cladosporium predominating. Botrytis showed in surprisingly high numbers when compared with other surveys, while Alternaria occurred in very low concentrations. Most atmospheric airborne spora were found between May and September. Aspergillus and Penicillium prevailed in the autumn and winter months, although were present the year-round. Momentary weather conditions seemed less important for the overall spore picture than the average meteorological characteristics for a whole season. The obtained aero-mycological information may be useful in determining clinical strategies for skin testing and serological investigations in patients with suspected mould allergies.

Childhood asthma and grass pollen aerobiology in Melbourne

Children from the Melbourne metropolitan area with laboratory proven bronchial sensitivity to ryegrass pollen were selected for a clinical trial which was run concurrently with an aerobiological survey during the grass pollen season of 1975 to 1976. During periods of high pollen counts, significant deterioration in the children's asthma occurred. The grass pollen season was of 10 weeks' duration with the highest daily counts during November and December. Highest diurnal pollen concentrations occurred at night and were associated with winds from the north, north-west, and south-east and with other meteorological factors.