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.

Food-dependent exercise-induced allergic reactions in Lipid Transfer Protein (LTP) hypersensitive subjects: new data and a critical reappraisal

Summary

Background. Lipid transfer protein is the main cause of both primary food allergy and food-dependent exercise-induced allergic reactions (FDEIAR) in Italy. What characterizes LTP-hypersensitive patients with FDEIAR is still unclear. We investigated the key characteristics of LTP-hypersensitive patients with or without FDEIAR in a large cohort of individuals sensitized to this allergen. Methods. 1,203 food-allergic patients, diagnosed on the basis of unequivocal clinical history and presence of circulating food allergen-specific IgE were studied. Serum IgE reactivity was assessed using the Allergen ExplorerALEX® system (Macroarray Diagnostics, Vienna, Austria). Association of specific IgE reactivities with FDEIAR was investigated, and patients with and without FDEIAR sensitized to LTP were compared. Results. 116 subjects (9.6%) had FDEIAR. Among these, 77 (66.3%) were LTP-reactors and 16 (13.8%) were sensitized to Tri a 19 (omega-5-gliadin). Different LTPs and omega-5-gliadin emerged as the sole allergens clearly associated with FDEIAR. Severity of allergic reactions was paralleled the level of specific IgE to LTPs. Patients with FDEIAR showed significantly lower IgE levels than their counterparts with food allergy at rest, and displayed nearly identical IgE levels regardless of the severity of allergic reactions induced by exercise. Conclusions. FDEIAR are associated with specific allergens. Specific IgE levels in LTP-hypersensitive patients with FDEIAR show an intermediate titer between those simply sensitized and those showing classic food allergy.

Investigating Novel Food Sensitization: A Real-Life Prevalence Study of Cricket, Locust, and Mealworm IgE-Reactivity in Naïve allergic Individuals

BACKGROUND AND OBJECTIVE

With the global population on the rise, edible insects are considered a potential solution to food security, although concerns about risks such as anaphylaxis exist.

METHODS

2,014 participants underwent testing with the Allergy Explorer-ALEX-2 including extracts of three novel foods: Acheta Domesticus (Ad), Locusta migratoria (Lm), and Tenebrio molitor (Tm). The IgE-mediated sensitization status was investigated in participants who had never knowingly consumed these insects. Data was recorded using an electronic database.

RESULTS

195 individuals (9.7% of all participants) were sensitized to insects. Tropomyosin was co-recognized by 34%, and 18.5% were positive for arginine kinases. Reactivity to Sarcoplasmic-CB, Troponin-C, Paramyosin, or Myosin-light-chain was found in less than 5% of the population, whereas 108 individuals (55.4%) did not show any reactivity to invertebrate panallergens. Additionally, 33 individuals (16.9%) exhibited monosensitization exclusively to insects. Multivariate analysis revealed an inverse association between arachnid reactivity and sensitization to insect allergens, while Mollusca, Blattoidea, and tropomyosin reactivity displayed a direct relationship. Furthermore, Myosin-light-chain reactivity correlated with Ad and Lm, and Troponin-C with Ad and Tm sensitization.

CONCLUSION

Edible insect extract IgE sensitization was observed in individuals without prior exposure to such foods. Mites showed a low likelihood of being primary sensitizers due to their inverse association with insect reactivity. Conversely, the direct association of insect sensitization with mollusk and cockroach extract reactivity suggests their potential as primary sensitizers in these participants. Tropomyosin consistently exhibited a positive association with reactivity to all studied insects, supporting its role as a primary sensitizer.

Clinical severity of LTP syndrome is associated with an expanded IgE repertoire, FDEIA, FDHIH, and LTP mono reactivity

Summary

Background. LTP allergy is often a challenge for clinicians. We evaluated a multiplex diagnostic approach with diverse cofactors to stratify LTP syndrome risk. Methods. Of the 1,831 participants screened with 'Allergy Explorer-ALEX-2', 426 had reactions to at least one LTP. Data was gathered and recorded via an electronic database. Results. Reactivity to peach Pru p 3 was found in 77% of individuals with LTP allergy. Higher levels of specific IgE and concurrent sensitization to more than 5 molecules (50% of all LTP-sensitised participants, 62% of symptomatic cases) were significantly associated with an increased risk of severe reactions (p = 0.001). Several cofactors, either alone or in combination, also influenced patients' clinical outcomes. Some cofactors increased the risk of severe reactions, such as mono reactivity to LTP in 44.6% of cases (p = 0.001), FDEIA in 10.8% of patients (p = 0.001), and FDNIH in 11.5% (p = 0.005). On the other hand, reactivity to PR10 (24.2%; p = 0.001), profilin hypersensitivity (10.3%; p = 0.001), and/or atopic dermatitis (16.7%; p = 0.001) had a mitigating effect on symptom severity. Conclusions. Clinical severity of LTP syndrome is associated with an expanded IgE repertoire in terms of the number of LTP components recognized and increased IgE levels in individual molecules. Ara h 9, Cor a 8, and Mal d 3 showed the strongest association with clinical severity. In addition, several cofactors may either exacerbate (FDEIA, FDHIH, and LTP monoreactivity) or ameliorate (atopic dermatitis and co-sensitization to profilin and/or PR10) individual patient outcomes. These factors may be utilized for the daily clinical management of LTP syndrome.

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.

Eosinophilic granulomatosis with polyangiitis (EGPA) and PRES: a case-based review of literature in ANCA-associated vasculitides

Eosinophilic granulomatosis with polyangiitis (EGPA) is a small-sized vessel systemic necrotizing vasculitis and belongs to the family of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides. The involvement of central nervous system in this condition is pretty rare. Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity described for the first time by Hinchey et al. (N Engl J Med 334(8):494-500, 1996) and characterized by MRI findings of reversible subcortical vasogenic edema predominantly in the white matter of posterior cerebral lobes. There are few case reports describing the concurrence of PRES with ANCA-associated vasculitides. We describe a case of PRES in a patient with a diagnosis of EGPA with a concise review of the literature. The exact cause of this syndrome is unknown. It has been related to eclampsia, drug-induced hypertension, renal insufficiency and also to rheumatologic diseases. Endothelial injury, hypertension and immunosuppressive medications can compromise the regulation of cerebral blood flow. In ANCA-associated vasculitides, patients presenting with symptoms of PRES represent a challenge to treatment with immunosuppressive medications. However, since an inflammatory process might be implicated, judicious use of these agents along with tight control of blood pressure and a supportive therapy may contribute to the resolution of the encephalopathic syndrome treating at the same time other manifestation related to the rheumatologic disease. Larger clinical studies are warranted to optimize the management of vasculitis-associated PRES.