Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study

BACKGROUND

Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach.

OBJECTIVE

To describe sensitization profiles and clinical phenotypes of pollen allergic patients in nine Southern European cities with a uniform methodological approach.

METHODS

Within the @IT.2020 multicenter observational study, pediatric and adult patients suffering from SAR were recruited in nine urban study centers located in seven countries. Clinical questionnaires, skin prick tests (SPT) and specific IgE (sIgE) tests with a customized multiplex assay (Euroimmun Labordiagnostika, Lübeck, Germany) were performed.

RESULTS

Three hundred forty-eight children (mean age 13.1 years, SD: 2.4 years) and 467 adults (mean age 35.7 years SD: 10.0 years) with a predominantly moderate to severe, persistent phenotype of SAR were recruited. Grass pollen major allergenic molecules (Phl p 1 and/or Phl p 5) ranged among the top three sensitizers in all study centers. Sensitization profiles were very heterogeneous, considering that patients in Rome were highly poly-sensitized (sIgE to 3.8 major allergenic molecules per patient), while mono-sensitization was prominent and heterogeneous in other cities, such as Marseille (sIgE to Cup a 1: n = 55/80, 68.8%) and Messina (sIgE to Par j 2: n = 47/82, 57.3%). Co-sensitization to perennial allergens, as well as allergic comorbidities also broadly varied between study centers.

CONCLUSIONS

In Southern European countries, pollen allergy is heterogeneous in terms of sensitization profiles and clinical manifestations. Despite the complexity, a unique molecular, multiplex, and customized in-vitro IgE test detected relevant sensitization in all study centers. Nevertheless, this geographical diversity in pollen allergic patients imposes localized clinical guidelines and study protocols for clinical trials of SAR in this climatically complex region.

Factors predicting the outcome of allergen-specific nasal provocation test in children with grass pollen allergic rhinitis

Background

Nasal provocation testing (NPT) is a reference methodology to identify the culprit allergen in patients with allergic rhinitis. Selecting the right allergen for NPT is particularly difficult in poly-sensitized patients with seasonal allergic rhinitis (SAR). Predictors of NPT outcomes may facilitate the proper use of this test or even substitute it.

Objective

To identify predictors of grass pollen NPT outcome from an array of clinical data, e-diary outcomes, and allergy test results in poly-sensitized pediatric patients with SAR.

Methods

Poly-sensitized, SAR patients with grass pollen allergy, participating in the @IT.2020 pilot project in Rome and Pordenone (Italy), participated in a baseline (T0) visit with questionnaires, skin prick testing (SPT), and blood sampling to measure total (ImmunoCAP, TFS, Sweden) and specific IgE antibodies to grass pollen extracts and their major allergenic molecules (ESEP, Euroimmun Labordiagnostika, Germany). During the pollen season, patients filled the AllergyMonitor® e-diary app measuring their symptoms, medication intake, and allergy-related well-being via the Visual Analogue Scale (VAS). After the pollen season (T1), patients answered clinical questionnaires and underwent a nasal provocation test (NPT) with grass pollen extract.

Results

We recruited 72 patients (age 14.3 ± 2.8 years, 46 males) sensitized to grass and/or other pollens, including olive (63; 87.5%) and pellitory (49; 68.1%). Patients positive to grass pollen NPT (61; 84.7%), compared to the negative ones, had worse VAS values in the e-diary, larger SPT wheal reactions, and higher IgE levels, as well as specific activity to timothy and Bermuda grass extracts, rPhl p 5 and nCyn d 1. A positive NPT to grass pollen was predicted by an index combining the specific activity of IgE towards Phl p 5 and Cyn d 1 (AUC: 0.82; p < 0.01; best cut-off ≥7.25%, sensitivity 70.5%, specificity: 90.9%). VAS results also predicted NPT positivity, although with less precision (AUC: 0.77, p < 0.01; best cut-off ≥7, sensitivity: 60.7%, specificity: 81.8%).

Conclusions

An index combining the specific activity of IgE to rPhl p 5 and nCyn d 1 predicted with moderate sensitivity and high specificity the outcome of a grass pollen NPT in complex, poly-sensitized pediatric patients with seasonal allergic rhinitis. Further studies are needed to improve the index sensitivity and to assess its usefulness for NPT allergen selection or as an alternative to this demanding test procedure.

Pollens causing allergy and their monitoring by aerobiology and phenology

Allergies caused by inhalant allergens, particularly pollens, are steadily increasing in urban centers. It is known that atmospheric pollution is strongly related to the inflammatory disease of the upper and lower airways but it is equally important in the development of sensitization towards pollens. Particulate Matter (PM), sulfur dioxide (SO2) and nitrogen dioxide (NO2) have an enhancement function on the persistence of pollens in the air, increasing the concentration and duration of pollinosis. It is therefore essential to use air quality control methods in urban centers to monitor the presence of pollen and fine dust that can drive the doctor and the patient to improve prevention, a step of primary importance in the treatment of allergies. Aerobiology and phenology are essential tools to monitor pollen production. The opportunity for the patients to use social media as information sources, including teletext, sms, mail and social networks, as well as a wide range of apps, allows to have reliable information on the air we breathe and therefore to better manage the methods of prevention at our disposal.

Pilot study on the short-term prediction of symptoms in children with hay fever monitored with e-Health technology

Forecasting symptoms of pollen-related allergic rhinoconjunctivitis at the level of individual patients would be useful to improve disease control and plan pharmacological intervention. Information Technology nowadays facilitates a more efficient and easier monitoring of patients with chronic diseases. We aimed this study at testing the efficiency of a model to short-term forecast symptoms of pollen-AR at the "individual" patient level. We analysed the data prospectively acquired from a group of 21 Italian children affected by pollen-related allergic rhinoconjunctivitis and recorded their symptoms and medication "Average Combined Score" (ACS) on a daily basis during April-June 2010-2011 through an informatics platform (Allergymonitor™). The dataset used for prediction included 15 variables in four categories: (A) date, (B) meteo-climatic, (C) atmospheric concentration of 5 pollen taxa, and (D) intensity of the patient's IgE sensitization. A Partial Least Squares Discriminant Analysis approach was used in order to predict ACS values above a fixed threshold value (0.5). The best performing predicting model correctly classified 77.8% ± 10.3% and 75.5% ± 13.2% of the recorded days in the model and test years, respectively. In this model, 9/21 patients showed ≥ 80% correct classification of the recorded days in both years. A better performance was associated with a higher degree of patient's atopic sensitization and a time lag > 1. Symptom forecasts of seasonal allergic rhinitis are possible in highly polysensitised patients in areas with complex pollen exposure. However, only predictive models tailored to the individual patient's allergic susceptibility are accurate enough. Multicenter studies in large population samples adopting the same acquisition data system on smart phones are now needed to confirm this encouraging outcome.