White cypress pine pollen: an important seasonal allergen source in rural Australia

Hay fever in a changing climate: linking an Internet-based diary with environmental data

Investigating the impact of climate change on human health requires the development of efficient tools that link patient symptoms with changing environmental variables. We developed an internet-based hay fever diary linked to simultaneously recorded pollen load and weather variables in Canberra, Australia over spring 2010. We recruited 42 hay fever sufferers to complete a simple online pollen diary daily over a period of 60 days. In conjunction, daily airborne pollen load was counted and meteorological data collected simultaneously. We focused on the relationships between temperature, rainfall, pollen count and rhinoconjunctivitis symptoms. Pollen load increased after a peak rainfall event until the end of the study. Compliance was high, averaging 79% of days per person. Nasal rhinoconjunctivitis symptoms increased in concert with increasing pollen load, and then remained high. Mucosal itching increased more gradually and strongly coincided with increased daily maximum temperature. Our study successfully demonstrated the feasibility of linking pollen load and climate variables to symptoms of rhinoconjunctivitis in the Australian community. However, a larger study would better explore the nature of associations between these variables. Similar online methods could be used to monitor a range of health responses to our changing environment.

Allergenic relationship between taxonomically diverse pollens

BACKGROUND

Skin tests and tests for IgE antibodies show that subjects are usually sensitive to a number of different pollens, frequently from taxonomically diverse species which are assumed to be allergenically non-crossreactive. This suggests that the presence of IgE antibody-reactivity to an individual pollen may not necessarily have resulted from contact with that pollen or even with a taxonomically closely related species.

OBJECTIVE

Since this has important consequences for allergen avoidance and desensitization of patients, we attempted to define allergenic relationships between diverse pollen species.

METHODS

Sera from subjects were examined in direct IgE antibody binding experiments and by quantitative inhibition, protein blotting and adsorption and elution studies.

RESULTS

Sera from subjects diagnosed as allergic to white cypress pine, Italian cypress, ryegrass or birch pollen were shown to have IgE antibodies that reacted with pollens from these four species and from cocksfoot, couch grass, lamb's quarter, wall pellitory, olive, plantain and ragweed. These reactions were confirmed in protein blotting and adsorption and elution studies where numerous IgE-binding bands were detected in all 11 different pollen extracts with sera from each of the different allergic categories. Further evidence of allergenic (i.e. IgE-binding crossreactivity between the different pollens was provided by inhibition studies in which clear-cut inhibitions of IgE binding to the different pollen allergen discs were obtained with comparable amounts of the different pollen extracts.

CONCLUSION

We conclude that the presence of pollen reactive IgE antibodies may not necessarily be a true reflection of sensitizing pollen species.

Cypress pollen allergy. Identification of allergens and crossreactivity between divergent species

Studies employing sera from 34 subjects allergic to white cypress pine (Callitris glaucophylla) pollen identified 18 IgE antibody-binding components in the pollen of this species, five of which (MWs approximately 94, 68, 64, 43 and 34 kDa) were recognized by all of the sera. Protein blotting and quantitative inhibition studies revealed clear cross-reactivity between C. glaucophylla and Cupressus sempervirens pollen proteins and striking similarities in the IgE recognition band patterns of the two pollens. Inhibition experiments with other pollen extracts revealed that sera from C. glaucophylla pollen-allergic subjects can be divided into two groups--those inhibited only by extracts from the two Cupressaceae pollens and those inhibited both by these pollen proteins and by pollen extracts from other species. Most of the crossreactions in the latter group cannot be explained on the basis of taxonomic relationships or separate sensitizations. As with previous studies on birch and olive pollens, we conclude that pollen allergenic crossreactivity is much more wide-ranging than generally believed.