IgE to cyclophilins in pollen-allergic children: Epidemiologic, clinical, and diagnostic relevance of a neglected panallergen.

BACKGROUND: Cyclophilins are ubiquitous panallergens whose epidemiologic, diagnostic, and clinical relevance is largely unknown and whose sensitization is rarely examined in routine allergy practice. OBJECTIVE: We investigated the epidemiologic, diagnostic, and clinical relevance of cyclophilins in seasonal allergic rhinitis and its comorbidities. METHODS: We examined a random sample of 253 (25%) of 1263 Italian children with seasonal allergic rhinitis from the Panallergens in Pediatrics (PAN-PED) cohort with characterized disease phenotypes. Nested studies of sensitization prevalence, correlation, and allergen extract inhibition were performed in patients sensitized to birch pollen extract but lacking IgE to Bet v 1/2/4 (74/1263) or with highest serum level of IgE to Bet v 1 (26/1263); and in patients with sensitization to various extracts (ragweed, mugwort, pellitory, Plantago, and plane tree), but not to their respective major allergenic molecule, profilins, and polcalcins. IgE to cyclophilin was detected with recombinant Bet v 7, and extract inhibition tests were performed with the same rBet v 7. RESULTS: IgE to rBet v 7 was detected in 43 (17%) of 253 patients. It was associated with asthma (P < .028) and oral allergy syndrome (P < .017) in univariate but not multivariate analysis adjusted for IgE to profilins (Phl p 12), PR-10s (Bet v 1), and lipid transfer proteins (Pru p 3). IgE to rBet v 7 was also highly prevalent (47/74, 63%) among patients with unexplained sensitization to birch pollen extract. In patients with unexplained sensitization to ragweed, mugwort, pellitory, Plantago and plane tree pollen, the levels of IgE to those extracts correlated with the levels of IgE to rBet v 7, and they were also significantly inhibited by rBet v 7 (inhibition range 45%-74%). CONCLUSIONS: IgE sensitization to cyclophilin is frequent in pollen-allergic patients living in temperate areas and can produce "false" positive outcomes in skin prick and IgE tests to pollen extracts. Molecular diagnostic guidelines should include this panallergen family.

IgE to cross-reactive carbohydrate determinants (CCD) in childhood: Prevalence, risk factors, putative origins.

BACKGROUND: IgE antibodies to cross-reactive carbohydrate determinants (CCD) are usually clinically irrelevant but they can be a cause of false positive outcomes of allergen-specific IgE tests in vitro. Their prevalence and levels have been so far cross-sectionally examined among adult allergic patients and much less is known about their origins and relevance in childhood. METHODS: We examined CCD with a cross-sectional approach in 1263 Italian pollen allergic children (Panallergen in Paediatrics, PAN-PED), as well as with a longitudinal approach in 612 German children (Multicenter Allergy Study, MAS), whose cutaneous and IgE sensitization profile to a broad panel of allergen extracts and molecules was already known. The presence and levels of IgE to CCD were examined in the sera of both cohorts using bromelain (MUXF3) as reagent and a novel chemiluminescence detection system, operating in a solid phase of fluorescently labelled and streptavidin-coated paramagnetic microparticles (NOVEOS, HYCOR, USA). RESULTS: IgE to CCD was found in 22% of the Italian pollen allergic children, mainly in association with an IgE response to grass pollen. Children with IgE to CCD had higher total IgE levels and were sensitized to more allergenic molecules of Phleum pratense than those with no IgE to CCD. Among participants of the German MAS birth cohort study, IgE to CCD emerged early in life (even at pre-school age), with IgE sensitization to group 1 and 4 allergen molecules of grasses, and almost invariably persisted over the full observation period. CONCLUSIONS: Our results contribute to dissect the immunological origins, onset, evolution and risk factors of CCD-sIgE response in childhood, and raise the hypothesis that group 1 and/or 4 allergen molecules of grass pollen are major inducers of these antibodies through an antigen-specific, T-B cell cognate interaction.

The "allergic nose as a pollen detector" concept: e-Diaries to predict pollen trends.

Hirst pollen traps and operator pollen recognition are worldwide used by aerobiologists, providing essential services for the diagnosis and monitoring of allergic patients. More recently, semiautomated or fully automated detector systems have been developed, which facilitate prediction of pollen exposure and risk for the individual patient. In parallel, smartphone apps consisting of short questionnaires filled in daily by the patient/user provide daily scores, time trajectories, and descriptive reports of the severity of respiratory allergies in patients with pollen allergy. The usual scientific and clinical approach to this matter is to monitor the environment (pollen concentration) in order to predict the risk of symptoms (allergic rhinitis) in a population. We discuss here the opposite, contraintuitive possibility, that is, the use of e-diaries to collect daily information of mono-sensitized pollen-allergic patients in order to predict the clinically efficient airborne exposure to a given pollen, area, and time period. In line with the "Patient as Sensor" concept, proposed in 2013 by Bernd Resch, the "allergic nose" may be used as a pollen detector in addition to existing calibrated hardware sensors, namely the pollen stations, thus contributing with individual measurements, sensations, and symptoms' perception. The target of this review is to present a novel concept of pollen monitoring based on "pollen-detector" patients to inspire future cooperative studies aimed at investigating and hopefully validating our hypothesis.

A singleplex IgE test to a mixture of molecules from multiple airborne allergen sources: Innovating in vitro screening of respiratory allergies.

BACKGROUND: In vitro immunoglobulin E (IgE) tests can be better standardized if based on molecules rather than extracts. However, singleplex screening tests for respiratory or food allergies are still based on extracts only. TARGET: To validate a novel singleplex IgE screening test for respiratory allergies, based on a mix of major allergenic molecules Der p 1, Der p 2, Fel d 1, Can f 1, Can f 2, Can f 3, Can f 5, Bet v 1, Phl p 1, and Art v 1 (Molecular SX01, NOVEOS, HYCOR, USA), and requiring only four microliters (µl) of serum. METHODS: We examined six subsets of sera from participants of the German Multicenter Allergy Study (MAS) birth cohort enrolling 1314 newborns during 1990: (1) monosensitized (n = 58); (2) polysensitized (n = 24); (3) nonsensitized, with total IgE levels above (n = 24) or (4) below (n = 24) 300 kU/L; (5) sensitized to milk and/or egg but not to airborne allergens (n = 24); and (6) sera of children aged ≤5 years at their earliest IgE monosensitization to airborne allergens (n = 41). Sera were analyzed with the novel molecular SX01 test (NOVEOS) and with three categories of comparators: ImmunoCAP Phadiatop SX01, extracts, and molecules of D. pteronyssinus, cat, dog, grass, and birch. Sensitivity, specificity, positive and negative predictive values were calculated. Quantitative interrelationships were determined using Spearman's rank-order correlation coefficient and Bland-Altmann plots. RESULTS: The molecular SX01 test predicted the outcome of IgE tests based on molecules, extracts, or Phadiatop in 188 (96.4%), 171 (87.7%), and 171 (87.7%) of the 195 sera, respectively. Accordingly, sensitivity was 93.5%, 89.0%, and 82.4%, whereas specificity was 100%, 97.6%, and 96.1% when compared with molecular, extract, and Phadiatop tests, respectively. Inconsistent outcomes were largely confined to sera with IgE-Ab levels around the cutoff value of 0.35 kU/L, except for 5/195 (2.5%) sera, containing high levels of IgE to Phl p 5 and/or Alt a 1 only. IgE levels measured by the molecular SX01 test and with IgE tests to molecules, extracts, and Phadiatop were highly correlated (rho 0.90; p < .001), (rho 0.87, p < .001), (rho 0.84, p < .001), respectively. The novel molecular SX01 test detected IgE-Ab in 27/28 (sensitivity 96.4%) of the sera of preschool children at their earliest IgE sensitization to the same molecules. DISCUSSION: Our study validates the prototype of a novel category of IgE test, based on molecular mixes. The test's rather good precision and accuracy in early screening IgE sensitization to airborne allergens in German children may be further improved by adding a few other molecules, such as Phl p 5 and Alt a 1.

Der p 23-specific IgE response throughout childhood and its association with allergic disease: A birth cohort study.

BACKGROUND: The Dermatophagoides pteronyssinus molecule Der p 23 is a major allergen whose clinical relevance has been shown in cross-sectional studies. We longitudinally analysed the trajectory of Der p 23-specific IgE antibody (sIgE) levels throughout childhood and youth, their early-life determinants and their clinical relevance for allergic rhinitis and asthma. METHODS: We obtained sera and clinical data of 191 participants of the German Multicentre Allergy Study, a prospective birth cohort. Serum samples from birth to 20 years of age with sIgE reactivity to Der p 23 in a customised semiquantitative microarray were newly analysed with a singleplex quantitative assay. Early mite exposure was assessed by measuring the average content of Der p 1 in house dust at 6 and 18 months. RESULTS: Der p 23-sIgE levels were detected at least once in 97/191 participants (51%). Prevalence of Der p 23 sensitisation and mean sIgE levels increased until age 10 years, plateaued until age 13 years and were lowest at age 20 years. Asthma, allergic rhinitis (AR) and atopic dermatitis (AD) were more prevalent in Der p 23-sensitised children, including those with monomolecular but persistent sensitisation (11/97, 11%). A higher exposure to mites in infancy and occurrence of AD before 5 years of age preceded the onset of Der p 23 sensitisation, which in turn preceded a higher incidence of asthma. CONCLUSIONS: Der p 23 sensitisation peaks in late childhood and then decreases. It is preceded by early mite exposure and AD. Asthma and AR can occur in patients persistently sensitised to Der p 23 as the only mite allergen, suggesting the inclusion of molecular testing of Der p 23-sIgE for subjects with clinical suspicion of HDM allergy but without sIgE to other major D.pt. allergens.

Validation study of a new chemiluminescent singleplex IgE assay in a set of Italian allergic rhinitis patients.

BACKGROUND: The measurement of specific IgE to allergenic extracts and molecules in patients with allergic rhinitis (AR) is crucial for a precise diagnosis and further immunotherapy. Companies providing in vitro diagnostic methods in allergology continuously strive for the optimization and modernization of such methods. A new generation of automated allergy tests based on chemiluminescence detection and paramagnetic microparticles is now available, with possible advantages in sample volume, cost-effectiveness and avoidance of sample-related interference. OBJECTIVES: To test whether sIgE antibody levels obtained with a new singleplex chemiluminescent method have a good agreement with the corresponding results obtained with a "gold standard" test. METHODS: We tested sera from 368 AR patients. Specific IgE sera levels (kU/L) to a comprehensive panel of 15 allergen extracts and 6 molecules were tested with ImmunoCAP® (Thermo Fisher Scientific Inc, Phadia AB, Uppsala, Sweden) and NOVEOS™ (HYCOR® Biomedical, Garden Grove, CA, USA). We evaluated the qualitative and quantitative performance of the new NOVEOS system in matching the outcome of ImmunoCAP to each of the examined allergens. RESULTS: In relation to ImmunoCAP, the overall diagnostic sensitivity and specificity of sIgE tests with NOVEOS were 90.8% (95% CI = 88.6-92.7) and 96.2% (95% CI = 93.9-97.8), respectively. These values were higher when only molecules were considered (sensitivity = 98.7% [95% CI = 96.4%-99.7%]; specificity = 94.2% [95% CI = 88.4%-97.6%]) and lower when only extracts were considered (sensitivity = 87.6% [95% CI = 84.7%-90.2%]; specificity = 97% [95% CI = 94.4%-98.6%]). Spearman's correlation between the data set of both methods for a ≥ 0.1 kU/L cut-off was 0.84 (p < .001). CONCLUSIONS: The new singleplex NOVEOS system presented good results for qualitative and quantitative comparisons when testing specific serum IgE antibodies against a range of 21 allergens. This novel immunoassay system using only 4 µl of sample per test appears to be robust and reliable and can, therefore, be used as an aid in allergy diagnosis.

@IT2020: An innovative algorithm for allergen immunotherapy prescription in seasonal allergic rhinitis.

BACKGROUND: Allergen immunotherapy (AIT) is the only disease-modifying treatment in patients with seasonal allergic rhinoconjunctivitis (SAR). Its efficacy depends on the precise identification of the triggering allergen. However, diagnostics based on retrospective clinical history and sensitization to whole extracts (SWE) often leads to equivocal results. OBJECTIVES: To assess the usability and impact of a recently established algorithm for a clinical decision support system (@IT2020-CDSS) for SAR and its diagnostic steps [anamnesis, SWE (skin prick test or serum IgE), component resolved diagnosis, CRD, and real-time digital symptom recording, eDiary] on doctor's AIT prescription decisions. METHODS: After educational training on the @IT2020-CDSS algorithm, 46 doctors (18 allergy specialists, AS, and 28 general practitioners, GP) expressed their hypothetical AIT prescription for 10 clinical index cases. Decisions were recorded repeatedly based on different steps of the algorithm. The usability and perceived impact of the algorithm were evaluated. RESULTS: The combined use of CRD and an eDiary increased the hypothetical AIT prescriptions, both among AS and GP (p < .01). AIT prescription for pollen and Alternaria allergy based on anamnesis and SWE was heterogeneous but converged towards a consensus by integrating CRD and eDiary information. Doctors considered the algorithm useful and recognized its potential in enhancing traditional diagnostics. CONCLUSIONS AND CLINICAL IMPLICATIONS: The implementation of CRD and eDiary in the @IT2020-CDSS algorithm improved consensus on AIT prescription for SAR among AS and GP. The potential usefulness of a CDSS for aetiological diagnosis of SAR and AIT prescription in real-world clinical practice deserves further investigation.

Toward personalization of asthma treatment according to trigger factors.

Asthma is a severe and chronic disabling disease affecting more than 300 million people worldwide. Although in the past few drugs for the treatment of asthma were available, new treatment options are currently emerging, which appear to be highly effective in certain subgroups of patients. Accordingly, there is a need for biomarkers that allow selection of patients for refined and personalized treatment strategies. Recently, serological chip tests based on microarrayed allergen molecules and peptides derived from the most common rhinovirus strains have been developed, which may discriminate 2 of the most common forms of asthma, that is, allergen- and virus-triggered asthma. In this perspective, we argue that classification of patients with asthma according to these common trigger factors may open new possibilities for personalized management of asthma.

The role of mobile health technologies in allergy care: An EAACI position paper.

Mobile health (mHealth) uses mobile communication devices such as smartphones and tablet computers to support and improve health-related services, data and information flow, patient self-management, surveillance, and disease management from the moment of first diagnosis to an optimized treatment. The European Academy of Allergy and Clinical Immunology created a task force to assess the state of the art and future potential of mHealth in allergology. The task force endorsed the "Be He@lthy, Be Mobile" WHO initiative and debated the quality, usability, efficiency, advantages, limitations, and risks of mobile solutions for allergic diseases. The results are summarized in this position paper, analyzing also the regulatory background with regard to the "General Data Protection Regulation" and Medical Directives of the European Community. The task force assessed the design, user engagement, content, potential of inducing behavioral change, credibility/accountability, and privacy policies of mHealth products. The perspectives of healthcare professionals and allergic patients are discussed, underlining the need of thorough investigation for an effective design of mHealth technologies as auxiliary tools to improve quality of care. Within the context of precision medicine, these could facilitate the change in perspective from clinician- to patient-centered care. The current and future potential of mHealth is then examined for specific areas of allergology, including allergic rhinitis, aerobiology, allergen immunotherapy, asthma, dermatological diseases, food allergies, anaphylaxis, insect venom, and drug allergy. The impact of mobile technologies and associated big data sets are outlined. Facts and recommendations for future mHealth initiatives within EAACI are listed.

The first, holistic immunological model of COVID-19: Implications for prevention, diagnosis, and public health measures.

The natural history of COVID-19 caused by SARS-CoV-2 is extremely variable, ranging from asymptomatic or mild infection, mainly in children, to multi-organ failure, eventually fatal, mainly in the eldest. We propose here the first model explaining how the outcome of first, crucial 10-15 days after infection, depends on the balance between the cumulative dose of viral exposure and the efficacy of the local innate immune response (natural IgA and IgM antibodies, mannose-binding lectin). If SARS-CoV-2 runs the blockade of this innate immunity and spreads from the upper airways to the alveoli in the early phases of the infections, it can replicate with no local resistance, causing pneumonia and releasing high amounts of antigens. The delayed and strong adaptive immune response (high-affinity IgM and IgG antibodies) that follows, causes severe inflammation and triggers mediator cascades (complement, coagulation, and cytokine storm), leading to complications often requiring intensive therapy and being, in some patients, fatal. Low-moderate physical activity can still be recommended. However, extreme physical activity and oral breathing with hyperventilation during the incubation days and early stages of COVID-19 facilitates re-inhalation and early direct penetration of high numbers of own virus particles in the lower airways and the alveoli, without impacting on the airway's mucosae covered by neutralizing antibodies ("viral auto-inhalation" phenomenon). This allows the virus to bypass the efficient immune barrier of the upper airway mucosa in already infected, young, and otherwise healthy athletes. In conclusion, whether the virus or the adaptive immune response reaches the lungs first is a crucial factor deciding the fate of the patient. This "quantitative and time-/sequence-dependent" model has several implications for prevention, diagnosis, and therapy of COVID-19 at all ages.

Digital allergology: Towards a clinical decision support system for allergen immunotherapy.

Mobile health is the "medical and public health practice supported by mobile devices, such as mobile phones, patient monitoring devices, personal digital assistants, and other wireless devices." For example, mobile apps (such as MASK-Air, Allergy.Monitor, Pollen, and others) have proven useful in the management of patients with allergic rhinitis. These apps can be used in the context of broader clinical decision support systems (CDSS) for enhancing allergy-related decisions and actions with pertinent, organized clinical knowledge and patient information to improve allergy care. A CDSS targeted to control rhinitis with drugs and other interventions guiding the patient in his/her self- and doctor-driven management is currently being produced and investigated by the MACVIA network. Another one, called @IT-2020, is targeted to support etiologic diagnostics and allergen immunotherapy (AIT) prescriptions for patients with seasonal allergic rhinitis. Intensive investigation is necessary to better define the advantages and limitations of mobile-health technology in allergology and establish guidelines for their proper use in daily practice in the context of a rapidly evolving European regulatory environment.

IgE antibody repertoire in nasal secretions of children and adults with seasonal allergic rhinitis: A molecular analysis.

BACKGROUND: There is growing interest both in testing IgE in nasal secretions (NS) and in molecular diagnosis of seasonal allergic rhinitis (SAR). Yet, the reliability of nasal IgE detection with the newest molecular assays has never been assessed in a large cohort of pollen allergic patients. OBJECTIVE: To investigate with microarray technology and compare the repertoires of specific IgE (sIgE) antibodies in NS and sera of a large population of children and adults with SAR. METHODS: Nasal secretions were collected with an absorbent device (Merocel 2000® , Medtronic) and a minimal dilution procedure from 90 children and 71 adults with SAR. Total IgE (tIgE) (ImmunoCAP, Thermo Fisher Scientific (TFS)) and sIgE antibodies against 112 allergen molecules (ISAC-112, TFS) were measured in NS and serum. RESULTS: Nasal sIgE was detectable in 68.3% of the patients. The detected nasal sIgE antibodies recognized airborne (88%), vegetable (10%), and animal food or other (<1%) allergen molecules. The prevalence and average levels of sIgE in NS and serum were highly interrelated at population level. A positive nasal sIgE antibody to a given molecule predicted the detection of the same antibody in the patient's serum with a specificity of 99.7% and a sensitivity of 40%. CONCLUSIONS: The concentration of sIgE is much lower in nasal secretions than in the serum. sIgE assays with very high analytical sensitivity and sampling methods with minimal dilution will be therefore needed to validate nasal secretions as alternative to serum in testing the sIgE repertoire.

EAACI Allergen Immunotherapy User's Guide.

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.

Validation of the analytical performance of the NOVEOS™ System, a system which improves upon the third-generation in vitro allergy testing technology.

Objectives Detection of allergen-specific immunoglobulin E (sIgE) is important for the diagnosis of allergy. IgE sensitization is commonly demonstrated in vivo by skin prick testing (SPT), or in vitro utilizing automated systems. Recently, HYCOR® Biomedical launched its new system for allergen sIgE testing called the NOVEOS™ Immunoanalyzer. This study aims to evaluate the analytical performance of the NOVEOS system in a bi-center study at Philipps-University Marburg (Site-1) and Charité Medical University Berlin (Site-2), respectively. Methods The analytical performance was evaluated based on the guidelines I/LA20-A3, EP5-A3, EP17-A2, EP6-A, EP7-A3, and EP9-A3 of the Clinical and Laboratory Standards Institute (CLSI). Results The conducted repeatability and within-laboratory precision tests provided acceptable performance with 3.0%-11.9% coefficient of variation across both sites. The limit of blank (LoB) and limit of detection (LoD) were <0.1 kU/L at both centers. A within-parameter linearity for all tested allergens was reported at both sites. Of note, no significant interference was observed for high levels of biotin, methylprednisolone, diphenhydramine, omalizumab, or ranitidine. Method comparison between the NOVEOS calibration and the latest World Health Organization (WHO) reference standard showed good agreement at both sites. Conclusions The results from the analytical performance of the NOVEOS allergen sIgE assay and instrument testing at both sites were comparable. Overall, a good precision and linearity as well as a detection limit <0.1 kU/L were observed, with minimal impact of common interfering substances on patient recoveries. The NOVEOS is calibrated to the latest WHO reference standard and adds benefits like a small sample size and para-magnetic microparticles that improve upon third-generation allergen sIgE assays' design and performance.

Adherence to Prescribed E-Diary Recording by Patients With Seasonal Allergic Rhinitis: Observational Study.

BACKGROUND: Complete diagnosis and therapy of seasonal allergic rhinoconjunctivitis require evidence that exposure to the sensitizing pollen triggers allergic symptoms. Electronic clinical diaries, by recording disease severity scores and pollen exposure, can demonstrate this association. However, patients who spontaneously download an e-diary app show very low adherence to their recording. OBJECTIVE: The objective of our study was to assess adherence of patients with seasonal allergic rhinitis to symptom recording via e-diary explicitly prescribed by an allergist within a blended care approach. METHODS: The @IT-2020 project is investigating the diagnostic synergy of mobile health and molecular allergology in patients with seasonal allergic rhinitis. In the pilot phase of the study, we recruited Italian children (Rome, Italy) and adults (Pordenone, Italy) with seasonal allergic rhinitis and instructed them to record their symptoms, medication intake, and general conditions daily through a mobile app (Allergy.Monitor) during the relevant pollen season. RESULTS: Overall, we recruited 101 Italian children (Rome) and 93 adults (Pordenone) with seasonal allergic rhinitis. Adherence to device use slowly declined during monitoring in 3 phases: phase A: first week, ≥1267/1358, 90%; phase B: second to sixth week, 4992/5884, 80% to 90%; and phase C: seventh week onward, 2063/2606, 70% to 80%. At the individual level, the adherence assessed in the second and third weeks of recording predicted with enough confidence (Rome: Spearman ρ=0.75; P<.001; Pordenone: ρ=0.81; P<.001) the overall patient adherence to recording and was inversely related to postponed reporting (ρ=-0.55; P<.001; in both centers). Recording adherence was significantly higher during the peak grass pollen season in Rome, but not in Pordenone. CONCLUSIONS: Adherence to daily recording in an e-diary, prescribed and motivated by an allergist in a blended care setting, was very high. This observation supports the use of e-diaries in addition to face-to-face visits for diagnosis and treatment of seasonal allergic rhinitis and deserves further investigation in real-life contexts.

Molecular diagnosis for allergen immunotherapy.

The extensive use of allergen molecules in birth cohort studies revealed that atopic sensitization is a sequential IgE response to distinct non-cross-reacting molecules from the same allergenic source (ie, molecular spreading), starting with an initiator molecule. This phenomenon reaches different degrees of progression (monomolecular, oligomolecular, and polymolecular) according to the individual atopic propensity and allergen exposure, thus producing an extreme heterogeneity of IgE sensitization profiles in patient populations. In patients with allergic rhinitis, the broader the IgE molecular sensitization profile, the greater is the risk of asthma and other allergic comorbidities, such as oral allergy syndrome. Hence it has been proposed to anticipate immunologic intervention at disease onset (early allergen immunotherapy) or even earlier during the preclinical sensitization stage (allergen immunoprophylaxis). Diagnostic algorithms based on singleplex or multiplex molecular IgE tests allow the discrimination of genuine from cross-reacting sensitization and the selection of the right extracts for allergen immunotherapy composition. Patients with extreme molecular poly-sensitization and greater risk of asthma or other IgE-mediated comorbidities, can be easily identified by means of allergen microarray or macroarray procedures and might benefit from anti-IgE treatment. IgE molecular tests have opened the era of precision allergology, and their routine use should aim at cost-effectiveness, according to the principles of the Choosing Wisely initiative.

A new molecular multiplex IgE assay for the diagnosis of pollen allergy in Mediterranean countries: A validation study.

BACKGROUND: The identification of the primary sensitizing pollen is difficult in Southern European patients with Seasonal Allergic Rhinitis (SAR) if sensitized to various pollen sources with overlapping seasonality. A more precise diagnosis is obtained by IgE assays to allergen molecules, currently available as singleplex or microarrays. OBJECTIVES: To test the analytical performance of a multi-parameter immunoblot molecular "Pollen Test" specifically designed to test IgE antibodies to pollen extracts and molecules clinically relevant in Southern Europe. METHODS: Sera were obtained from 101 children and 98 adults with SAR and tested with a customized multiplex immunoblot assay (EUROLINE Southern European Pollen Profile [ESEP]; EUROIMMUN AG, Luebeck, Germany) containing a comprehensive panel of allergen extracts and molecules. ESEP's outcomes were then compared in selected sera (ESEP positive to negative = 2:1) with those of singleplex IgE assays (ImmunoCAP; ThermoFisher Scientific, Uppsala, Sweden). For each of the examined reagents, qualitative (sensitivity, specificity, accuracy), semi-quantitative (classes) and quantitative (Spearman's rank correlation, Bland-Altmann plots) comparisons were performed. RESULTS: Compared to ImmunoCAP, cumulative ESEP's sensitivity and specificity were 87% (95% CI 84%-90%) and 88% (83%-93%) for extracts and 99% (98%-100%) and 87% (83%-91%) for molecules. Cohen's kappa coefficients (κC ) ranged for extracts from 0.18 (Pellitory) to 0.50 (Cypress) and for molecules from 0.21 (Ole e 1) to 0.68 (Phl p 7). The quantitative outcomes of the two diagnostic tests were highly correlated, with Spearman's rank correlation coefficients always exceeding 0.80. Bland-Altmann plots showed a tendency of ESEP to overestimate serum specific IgE levels, when compared to ImmunoCAP. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitivity and specificity of ESEP in testing serum IgE antibodies against pollen allergen extracts and molecules, in Italian patients with SAR, both exceeded 85%. The advantages and limitations of a multiplex customized immunoblot assay, in the routine clinical use of molecular diagnostics in Southern European pollen allergic patients, deserve to be tested.

Early molecular biomarkers predicting the evolution of allergic rhinitis and its comorbidities: A longitudinal multicenter study of a patient cohort.

BACKGROUND: Pollen-related seasonal allergic rhinoconjunctivitis (SAR) is a very frequent pediatric disease in Westernized countries. Risk factors and disease phenotypes have been thoroughly examined in several cross-sectional studies. By contrast, only a few studies have examined disease evolution in patient cohorts. We investigated predictive biomarkers of disease evolution in a large cohort of children with SAR. METHODS: During 2015-2017 (follow-up), we re-examined 401 patients from those enrolled in 2009-2011 (baseline) by the "Panallergens in Pediatrics" study, a large multicenter survey of Italian children with SAR. Information on clinical history (standard questionnaire, AllergyCARD®; TPS, Italy) and skin prick tests for inhalant and foods extracts (ALK-Abelló, Hørsholm, Denmark) was acquired as at baseline visit. Evolution in clinical and sensitization data of patients was analyzed over time, as well as their association with the main baseline characteristics and atopy risk factors. RESULTS: The average age of participants was 10.4 ± 3.4 years at baseline and 16.2 ± 3.6 years at follow-up. SAR persisted in 93.3% of patients at follow-up and became more frequently associated with asthma (from 36.7% at baseline to 48.6% at follow-up) and oral allergy syndrome (OAS, from 23.4% to 37.7%). Compared to baseline, the prevalence of skin sensitization to some pollens (Phleum pratense, Corylus avellana, Platanus acerifolia, Artemisia vulgaris) and vegetables (hazelnut, wheat, and apple) significantly decreased at follow-up. Earlier onset of SAR and polysensitization at baseline were associated with incident asthma at follow-up. The presence at baseline of serum IgE to the following allergen molecules was identified as biomarkers of clinical evolution: (a) Phl p 1, for persistence of SAR; (b) Phl p 5, for persistence of both rhinitis and asthma; (c) Pru p 3, for new onset of asthma; (d) Bet v 1, for persistence of OAS. CONCLUSIONS: Seasonal allergic rhinoconjunctivitis is clinically heterogeneous in its evolution from childhood to adolescence. The detection of serum IgE to specific molecules (Phl p 1, Phl p 5, Bet v 1, Pru p 3) may be useful as biomarkers to predict SAR persistence and future onset of comorbidities, such as asthma and/or OAS.

Allergy and atopy from infancy to adulthood: Messages from the German birth cohort MAS.

OBJECTIVE: We present an overview of important results obtained during the first 20 years of the Multicenter Allergy Study (MAS), one of the first and longest-running population-based birth cohorts focusing on asthma and allergy. DATA SOURCE/STUDY SELECTIONS: The MAS is an observational population-based allergy-risk enriched cohort of 1,314 newborns enrolled in Germany in 1990. Assessments of various lifestyle and environmental exposures took place at 19 points, including 9 clinical visits for physical examinations and biosampling up to age 20 years. RESULTS: A positive allergic family history was a strong predictor of asthma from childhood up to adulthood, more so for allergic multimorbidity than single allergic entities. For asthma prevalence, the early male preponderance shifted toward females during adolescence, leading to a sex-balanced distribution by age 20 years. Eczema prevalence switched toward a clear and persisting female predominance, whereas allergic rhinitis continued to affect more males up to age 20 years. The immunoglobulin (Ig) E antibody response to grass evolved in many allergic children from a simple, often mono- and oligomolecular to a polymolecular sensitization stage ("molecular spreading"). Indoor allergen exposure increased the risk for specific sensitization, which was linked to asthma and impaired lung function at early school-age. Moreover, the MAS birth cohort has made important contributions to the investigation of genetic factors in the manifestation of clinical subphenotypes and in the long-term temporal trajectory of allergic diseases. CONCLUSION: Follow-up assessments over 2 decades provided new insights into risk factors and predictors for eczema, rhinitis, and asthma up to adulthood to develop better prevention strategies.