Sensitization to subtropical grass pollens in patients with seasonal allergic rhinitis from Bahia Blanca, Argentina

Abstract

BackgroundGrass pollinosis is an important contributor to allergic diseases, with varying patterns and frequency of allergens according to the geographical location studied. Our study aims to provide a better understanding of subtropical grass pollinosis in Argentinian patients with seasonal allergic rhinitis.MethodsWe conducted a retrospective cross-sectional study involving 894 patients with seasonal allergic rhinitis from Bahía Blanca, Argentina. Skin prick tests were performed to selected pollen species belonging to three subfamilies of the Poaceae genera. Frequency of sensitization to specific grass pollen extracts, cross-reactivity of allergens assessed by skin prick test, and possible associations between allergen extracts and asthma or allergic conjunctivitis were analyzed.ResultsSensitization to the Pooideae subfamily was the most frequent, encompassing 86.8% (CI: 84.4%–88.9%) of the studied population. Positive reactions to allergen extracts from the Chloridoideae and the Panicoideae subfamilies showed smaller papule size than allergen extracts from the Pooideae subfamily (χ2(5) = 83.75, p < 0.001). Patients with a positive skin prick test (SPT) to a specific extract were more likely to present some degree of cross-reactivity to the remaining pollens when compared to patients with negative SPT to the same specific extract. Even though the proportion of patients presenting with asthma (46.9%) was higher than those with conjunctivitis (22.6%), there was only a statistically significant association between sensitization to Festuca arundinacea (φ = 0.089, p = .009), Phalaris arundinacea (φ = 0.074, p = .032) and Paspalum notatum (φ = 0.070, p = .038) and the presence of conjunctivitis.ConclusionsOur results suggest a high frequency of sensitization to grass pollen extracts from the Poaceae family among patients with seasonal allergic rhinitis. Overall, sensitization to the Pooidae subfamily was the most common, where Phalaris arundinacea presented the highest frequency.

Latin American Guideline on the Diagnosis and Treatment of Ocular Allergy - On behalf of the Latin American Society of Allergy, Asthma and Immunology (SLAAI)

“…Recent studies of these subtropical species describe their own allergens that they do not share with the Pooideae. 32,33 There is a wide variety of species that do not belong to trees and grasses, which is often called a "weed group", or weeds, in English. This is a group that encompasses a large number of genera, making it difficult to use a single taxonomic name.…”

<p>Major Pollen Allergen Components and CCD Detection in Bermuda Grass Sensitized Patients in Guangzhou, China</p>

“…A study in Argentina has shown that 43.5% of asthma patients were positive to Cyn d 12. 3 With the advantage of CRD, which provides a more accurate sensitization profile, we were able to identify the correlation between disease and particular allergen components.…”

“…1,2 Recent research from Argentina found that 48.1% of patients with seasonal allergic rhinitis were sensitized to Bermuda grass pollen, while in Thailand, the positive rate of Bermuda grass was 21.1% in patients with allergic diseases by skin prick test. 3,4 Our previous research found that more than 60% of Bermuda grass sensitized rhinitis/asthma patients were sensitized to Timothy grass, while another study showed that some Bermuda grass sensitized patients were also co-sensitized to Mugwort. 5 It is likely that these allergens might contain the same protein components inducing cross-reactive.…”

Year-long trends of airborne pollen in Argentina: More research is needed

“…5 In another study, it was found that among patients with seasonal allergic rhinitis there was a high frequency of sensitization to grass pollen extracts. 6 …”

“…10 Even though it is not under the scope of this study, it is likely that the prevalence of allergic diseases follows this pattern, since it has been reported in Argentina that grass allergen extracts induce the strongest positive reactions when compared to tree and weed extracts; grass have high cross-reactivity between them and only 4 pollen grains/m 3 are required to elicit a response, all of which represent factors that favor hypersensitivity. 6 , 21 , 22 …”