Neural networks for increased accuracy of allergenic pollen monitoring.

Monitoring of airborne pollen concentrations provides an important source of information for the globally increasing number of hay fever patients. Airborne pollen is traditionally counted under the microscope, but with the latest developments in image recognition methods, automating this process has become feasible. A challenge that persists, however, is that many pollen grains cannot be distinguished beyond the genus or family level using a microscope. Here, we assess the use of Convolutional Neural Networks (CNNs) to increase taxonomic accuracy for airborne pollen. As a case study we use the nettle family (Urticaceae), which contains two main genera (Urtica and Parietaria) common in European landscapes which pollen cannot be separated by trained specialists. While pollen from Urtica species has very low allergenic relevance, pollen from several species of Parietaria is severely allergenic. We collect pollen from both fresh as well as from herbarium specimens and use these without the often used acetolysis step to train the CNN model. The models show that unacetolyzed Urticaceae pollen grains can be distinguished with > 98% accuracy. We then apply our model on before unseen Urticaceae pollen collected from aerobiological samples and show that the genera can be confidently distinguished, despite the more challenging input images that are often overlain by debris. Our method can also be applied to other pollen families in the future and will thus help to make allergenic pollen monitoring more specific.

Allergenicity at component level of sub-pollen particles from different sources obtained by osmolar shock: A molecular approach to thunderstorm-related asthma outbreaks.

BACKGROUND: The so-called "thunderstorm asthma" (TA) is an uncommon but dramatic outbreak of asthma attacks occurring during a thunderstorm in the pollen and moulds season. Mechanisms which make the pollen able to enter the deeper airways and provoke severe asthma symptoms are still unclear. OBJECTIVE: To test the hypothesis that sub-pollen particles (SPPs) originated from the rupture by an osmotic shock of pollen associated with TA contain allergens. METHODS: After hydration, SPPs released from pollen grains of grass, pellitory, olive, cypress, ragweed and birch were isolated and determined by microscopy. Allergens were determined by in vitro ELISA inhibition tests indirectly using the sera from 10 polyreactive patients. An inhibition <50% was considered as negative, 50%-75% moderate and > 75% complete. RESULTS: The inhibition experiments showed that the SPPs from birch and cypress were unable to inhibit serum IgE reactivity to Bet v 1 and Cup a 1, respectively. Ragweed SPPs inhibited ragweed pollen extract and Amb a 1 by 75.8 ± 0.11% and 81.2 ± 0.15%, respectively. Olive and pellitory SPPs retained almost the whole IgE-binding capability in all cases tested. Grass SPPs inhibited 32 ± 0.06% of Lolium perenne Lol p 1 and 65% of Phleum pratense extracts, but results were highly variable for individual allergens (97.5%-0.03% for Phl p 2, 45.3 ± 0.12% for Phl p 5, 24.7 ± 0.22% for Phl p 6, and 38.3 ± 0.2% for Phl p 1). CONCLUSIONS: Inhibition experiments confirm the hypothesis that SSPs obtained after the osmotic shock of pollen involved in TA, namely grass, pellitory and olive tree pollen, contain allergens and therefore they can induce severe asthma attacks during thunderstorms.

Safety and treatment compliance of subcutaneous immunotherapy: A 30-year retrospective study.

BACKGROUND: Safety and treatment compliance are still considered important shortcomings of subcutaneous immunotherapy (SCIT). OBJECTIVE: To assess the rate of side effects (SE) to SCIT and treatment compliance at a hospital medically supervised facility. METHODS: A retrospective review of patients with allergic rhino-conjunctivitis (ARC) with or without asthma, who received SCIT to mites and pollens from 1988 to 2018, was performed. The information was collected from patient's allergen immunotherapy forms that had been prospectically filled in by expert physicians. RESULTS: Two thousand two hundred patients (50.2% males; mean age 29.4 ±â€¯11.7 years) received 3037 SCIT courses. A total of 91,187 injections were given, with a mean SCIT duration of 2.5 ±â€¯1.9 years. Nine hundred fifty-seven patients (43.5%) were compliant as they completed the minimally required treatment duration of 3 years. A total of 1087 SE (1.2% of all injections; 76.8% local reactions) were reported in 513 patients (23.3%). There were 42 anaphylactic reactions (in 29 patients) during the study period; two of these were severe. Adrenalin was administered only once. No anaphylactic shock was reported. Only 39 patients (1.8%) discontinued SCIT because of SE, the majority of whom (24; 61.5%) because of systemic reactions (urticaria, asthma, anaphylaxis). Parietaria vaccines were the most frequently associated to SE. Female gender, number of vaccines administered (2 vaccine vs. 1 vaccine) and year of SCIT inception (1996-2018 vs. 1988-1995) were independently associated to SE. CONCLUSION: SCIT, although not absolutely free of risk, is safe and well tolerated. There is still room for improvement of treatment compliance.

Pru p 3 sensitization in children with allergy to Parietaria pollens.

BACKGROUND: Pru p 3 is the major allergen of the peach and belongs to the LTP family. Pru p 3 sensitization has been associated with severe allergic symptoms after eating LTP-containing foods. However, a previous experience partially downsized the potential danger of Pru p 3 sensitization in a group of adult rhinitics. This study aimed to evaluate the real impact of Pru p 3 sensitization in children in a real-world setting. METHODS: 82 consecutive paediatric patients (55 males and 27 females, mean age 8.19±4.23 years) with allergic rhinitis due to Parietaria pollen allergy and sensitization to Pru p 3, documented by ISAC test, were evaluated. Serum IgE was measured by ImmunoCap method. Allergic symptoms occurring after ingesting LTP-containing foods were considered and scored as oral allergy syndrome, food allergy, and anaphylaxis. RESULTS: About one-quarter of Pru p 3-sensitized children reported anaphylaxis after ingesting LTP-containing foods, about half reported food allergy or oral allergy syndrome. Only » was merely sensitized. CONCLUSIONS: Pru p 3 sensitization deserves careful attention in children contrary to what might occur in adult patients. It could depend on the age and the serum IgE level. Thus, Pru p 3 sensitization should be adequately interepreted and managed in clinical practice.

Detection of profilin in SPT extracts that are supposed to contain it

Introduction and objectives: Profilin is a panallergen contained in pollen, plant foods and latex. Although cross-reactivity is expected while performing skin prick tests (SPT) with allergens that contain profilin, this is not always noticed. The purpose of this study was to detect if profilin is contained in the commercial SPT extracts of pollen and plant foods which, in their fresh form, contain determined epitopes of profilin. Material and methods: Commercial SPT extracts of different pharmaceuticals were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The study included purified palm date profilin, peach (whole, pulp and peel extracts), hazelnut, Olea europea, Parietaria judaica and Phleum pratense. Results: Profilin was detected in all, but peach extracts; it was neither contained in the whole peach extract nor in the ones of peel or pulp. Conclusion: The only accurate way to detect sensitization to profilin, while performing SPT, is the use of purified profilin extract. Even if a plant food or pollen contain an identified molecule of profilin, the relevant SPT commercial extract may not

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Allergy in adolescent population (14-18 years) living in Campania region (Southern Italy). A multicenter study.

Summary: Adolescents (Ad) constitute a difficult to manage population among individuals suffering from asthma. The aim of our study was to assess the prevalence, clinical characteristics and age of onset of allergic sensitization and clinical symptoms in a sample of atopic Ad living in the Campania region (Southern Italy). Sixteen Allergy units or Centers belonging to the Italian Association of Hospital and Territorial Allergologists (AAIITO, Campania region) participated in this cross-sectional study. A case report form (CRF) was specifically designed for this study and commercial allergen extracts used for screening SPTs were provided by ALK-Abelló Group (Milan, Italy). A total of 443 patients were examined (females, f 220, 49.6 %; males, m 223, 50.3%). Dust mites represent the most common sensitizing agents in allergic Ad living in Campania region (Dermatoph. pteronyssinus 67.4% and Dermatoph. farinae 66.5%), followed by Parietaria (58.9%), grasses (45.8%), Artemisia vulgaris (16.7%), Olea Europaea (32.2%), dog dander (17.1%), cat dander (20.0%), Alternaria alternata (8.1%), Cupressus sempervirens (4.9%), Betula pendula (4.7%), other allergens (19.4%). An interesting comparison has been made between clinical data of our Ad with data of elderly patients (E). The role of allergic sensitization is significantly higher in Ad compared to E. Dermatophagoides pteronyssinus is the first sensitizing allergen in Ad and the last in E. Parietaria constitutes the first sensitizing pollen both in Ad and E, the percentage of sensitization is higher in Ad. Another important difference is the higher prevalence of As, as only symptom, in E compared to Ad (19.7% versus 7.6%). In conclusion, our findings confirm the high prevalence and clinical significance of airway allergic sensitization in the adolescents living in Campania region.

Detection of profilin in SPT extracts that are supposed to contain it.

INTRODUCTION AND OBJECTIVES: Profilin is a panallergen contained in pollen, plant foods and latex. Although cross-reactivity is expected while performing skin prick tests (SPT) with allergens that contain profilin, this is not always noticed. The purpose of this study was to detect if profilin is contained in the commercial SPT extracts of pollen and plant foods which, in their fresh form, contain determined epitopes of profilin. MATERIAL AND METHODS: Commercial SPT extracts of different pharmaceuticals were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The study included purified palm date profilin, peach (whole, pulp and peel extracts), hazelnut, Olea europea, Parietaria judaica and Phleum pratense. RESULTS: Profilin was detected in all, but peach extracts; it was neither contained in the whole peach extract nor in the ones of peel or pulp. CONCLUSION: The only accurate way to detect sensitization to profilin, while performing SPT, is the use of purified profilin extract. Even if a plant food or pollen contain an identified molecule of profilin, the relevant SPT commercial extract may not.

Parietaria Allergy: An Intriguing Challenge for the Allergist.

Parietaria pollen is the most important cause of pollen allergies in the Mediterranean area, as Parietaria is widespread in this region. Many issues are associated with Parietaria allergy, including the duration of the pollen season (many doctors in fact believe that it lasts throughout the year), pollen load (which seems to be increasing over time), the impact of age (on IgE production and symptom severity), inflammatory changes (after pollen exposure), and the choice of allergen immunotherapy (AIT). In addition, molecular diagnostics allows for the defining of a correct diagnosis, differentiating between mere sensitization and true allergy. This review considers these topics and will hopefully help the allergist in clinical practice. Parietaria allergy is an intriguing challenge for the allergist in clinical practice, but it may be adequately managed by knowing the peculiarities of respective territories and the clinical characteristics of each patient.

Tolerability and positive efficacy results after subcutaneous immunotherapy with Parietaria judaica depot extract.

AIM: To evaluate tolerability and efficacy of Parietaria judaica subcutaneous immunotherapy on patients with allergic rhinoconjunctivitis. PATIENTS & METHODS: 51 patients were assigned to build-up scheme (six increasing doses) of P. judaica depot native extract, plus three maintenance monthly administrations. RESULTS: Out of 470 administered doses, only 3.8% elicited systemic reactions (1.5% nonspecific and 2.3% grade I). Concerning the exploratory efficacy parameters: cutaneous reactivity at the final visit versus baseline was significantly decreased; specific titers of IgG and IgG4 increased significantly and patients showed a significant decrease in the rhinitis symptoms score. CONCLUSION: P. judaica subcutaneous immunotherapy (Allergovac® depot ROXALL Medicina España S.A., Zamudio, Spain) with an abbreviated up-dosing scheme showed an adequate safety and tolerability profile and induced preliminary efficacy changes.

Basophil biomarkers as useful predictors for sublingual immunotherapy in allergic rhinitis.

Prevalence of allergic diseases is increasing worldwide. Allergen-specific immunotherapy (ASIT) is potentially the only curative treatment for allergy, but there is a lack of reliable methods to monitor the immune responses to ASIT and to predict clinical efficacy. Recently, the definition of allergen sensitivity threshold (CD-Sens) by Basophil Activation Tests has been suggested as potential method in this context. The aim of this study was to compare trends of CD-Sens, measured by the markers CD63 and CD203c, and clinical symptoms in subjects with allergic rhinitis receiving Sublingual Immunotherapy (SLIT). 26 rhinitis patients allergic to Parietaria were selected and matched into two groups; a SLIT treated group (SG) and a reference group (RG) treated by traditional anti-allergic medications. Visual Analogue Scale (VAS) score for the four cardinal symptoms of rhinitis and peripheral blood was collected before the first dose of SLIT (T0) and after 12 months (T12) to define the severity of the symptoms and the sensitivity of basophils to Parietaria. The comparison between T0 and T12 in SG patients showed a significant decrease of symptom severity (VAS score) and an increased tolerability of basophils to Parietaria (CD-Sens) both by CD63 and CD203c. But, only CD203c seems to be correlated with the clinical symptoms. These data corroborate the hypothesis that SLIT could change the immunological course of allergic sensitization already in the first year, and that an immunological parameter as CD-Sens measured by CD63 and CD203c expression on stimulated basophils could be useful to monitor the changes in the immune system.

Parietaria pollination duration: myth or fact?

Background. Even though the Parietaria pollen season may be rather long, it is commonly thought that Parietaria pollen is a perennial allergen present along the whole year. Objective. This study aimed at investigating the duration of Parietaria pollen season during a 10-year period in Italy, analysing also the annual pollen quantity and the differences among geographical areas. Methods. Pollen count was assessed daily for 10 years. Globally, ten Italian centers measured Parietaria pollen count. Start date, peak date, end date, duration (days), peak value, and seasonal pollen index were evaluated in each center. Results. Ten-year Parietaria pollen count demonstrates that the pollen season usually lasted for 6-7 months in Italy. There are important differences among centres, mainly attributable to geoclimatic factors. Conclusion. This study demonstrates that Parietaria pollen season lasts about 6-7 months with two peaks (mainly in spring and lower in autumn) in Italy with important geographical variations. This information may have clinical relevance in managing patients allergic to Parietaria.

Allergic sensitization prevalence in a children and adolescent population of northeastern Greece region.

OBJECTIVES: To evaluate the prevalence of allergic sensitization in a childhood and adolescent population, to explore age- and gender-specific variations and finally to discover co-sensitivities among allergens. METHODS: A two-stage cross-sectional survey among school-aged children. The two stages of the study involved enrollment of schools and then skin prick testing (SPT) within schools. A total of 675 school children were included in the study. Of those, 231 were diagnosed with allergic rhinitis (AR), according to the medical history as provided by parental-completed questionnaires and positive SPT results. The antigen panel consisted of common allergens and more specifically house dust mites-HDM (Dermatophagoides farinae and Dermatophagoides pteronyssinus), grass mix, trees (olive, cypress and pine), weeds (Parietaria spp.), cat and dog epithelium and moulds (Alternaria spp., Cladosporium spp.). The SPT sensitivity was graded according to SPT-USA Standards. RESULTS: The overall prevalence rate of AR was 34.22%. In total, 93 school children (40.3%) were mono- and 138 (59.7%) were poly-sensitized. Overall, the most prevalent sensitizations in decreasing order were to HDM (59.74%), to grasses (48.9%), to Alternaria (34.6%) and to olive (14.71%). There were no age- and sex-specific differences, except for Alternaria mould that showed a significant prevalence among primary school-aged children and predominance in the female gender, by contrast to grass pollen allergy that was predominant to males. A 32% of SPT-positive individuals were not aware of their allergy, with no statistically significant differences between ages. Co-sensitivities were detected for grass pollens and pine and olive trees, for Alternaria and Cladosporium moulds, for cypress and pine trees, and finally for dog and cat danders. CONCLUSIONS: Given data among school-aged children should be a baseline from which to monitor disease trends and is considered important for the optimal management of AR patients.

Serum allergen-specific IgE, allergic rhinitis severity, and age.

BACKGROUND: Allergic rhinitis (AR) is characterized by an IgE-mediated reaction. Aging usually induces a progressive decline of immune system function. There is common belief that both allergic symptoms severity and serum IgE production decline during aging. OBJECTIVE: This study aimed to evaluate the possible impact of age on: i) serum allergen-specific IgE levels in a large sample of subjects, and ii) AR symptom severity in a group of mono-allergic patients. METHODS: Serum allergen-specific IgE to birch, Bet v 1, Parietaria, and Dermatophagoides pteronyssinus were measured by immunofluorometric assay (IFMA) in a sample of 8098 subjects. AR symptom severity was assessed by visual analogue scale (VAS) in a sub-group of 531 mono-allergic patients. RESULTS: The analysis of variance showed that IgE to Bet v 1, birch, and Dermatophagoides pteronyssinus significantly decreased considering the age, whereas IgE to Parietaria did not significantly decline in respect of the age. Considering the global sample of mono-allergic patients, elderly subjects (over 65 years old) tended to have lower IgE levels, but had significantly lower VAS rating, and significantly less sensitizations than adult subjects (18-65 years old). In both adult and elderly patients VAS strongly correlated with IgE values. CONCLUSIONS: Allergen-specific IgE levels tend to reduce with aging, but with differences between types of allergy. The IgE decrease is usually associated with reduced AR symptom severity. Elderly AR patients seem to have a different phenotype/endotype in comparison with adult AR ones, characterized by milder symptoms, lower IgE production, and less sensitizations. However, a close positive relationship between IgE values and VAS scores is shared by both adult and elderly AR patients, confirming the close link between allergy and symptoms that persists also in the elderly.

Pre-co-seasonal Allergen Immunotherapy in Parietaria allergic patients.

BACKGROUND: Even though the Parietaria pollen season may be rather long, many physicians think that Parietaria pollen is a perennial allergen present along the whole year. In fact, many doctors prefer to prescribe allergen immunotherapy (AIT) in Parietaria allergic patients, using continuous courses. On the other hand, physicians usually prescribe pre-co-seasonal AIT course for other pollen allergies. OBJECTIVE: This study aimed at investigating whether a single pre-co-seasonal AIT course could be effective in Parietaria allergic patients. METHODS: Globally, 59 subjects (31 males, mean age 35.9 years) were retrospectively evaluated. All were treated with SLIT as a pre-co-seasonal course: 33 with Parietaria extract and 26 with birch extract. Patients' perception of symptom severity and medication use was assessed by visual analogue scale, comparing the previous pollen season and the present. RESULTS: The Parietaria 2012 pollen season started from the 60(th) day and ended at the 205(th) day of 2012. A single pre-co-seasonal SLIT course was able to significantly (p < 0.0001) reduce symptom severity and medication use. CONCLUSION: This preliminary study demonstrates that Parietaria pollen season in Genoa lasted about six months and a single pre-co-seasonal SLIT Parietaria course could be sufficient to reduce symptom severity and medication use.

Evaluation of methods for the estimation of threshold concentrations by the skin prick test.

BACKGROUND: The allergen dose-response curve is flat; thus, small changes in wheal size reflect large differences in skin sensitivity. The sensitivity as measured by provocation tests is given by the threshold concentration that causes symptoms and/or objective signs. The threshold concentrations differ by several magnitudes between the most and the least sensitive individuals clinically allergic to the same allergen. Variation in technique can be minimized by relating allergen responses to that to histamine. The aim here is to present and validate simple methods for estimation of the skin sensitivity given as the concentration inducing a wheal of the same size as that with the positive reference, 10 mg/ml of histamine HCl, in the same patient. METHODS: Data from previously reported trials on the biological equilibration of allergen extracts were used to document a method to calculate the concentration of allergen required to induce a wheal of the same size as that with 10 mg/ml of histamine dihydrochloride in the same patient, and to validate the methods using the parallel line bioassay as the gold standard. RESULTS: The validated methods correlated well with the results obtained using the gold standard method and provide results of skin prick testing based on threshold concentrations of allergen. CONCLUSIONS: The validated methods reduce the error of differences in testing techniques and make it possible to report skin sensitivity at threshold concentrations. A simple method to be used in clinical practice and a method suitable to describe changes in skin reactivity over time or during treatment are proposed.

Clinical bystander effect exerted by allergen immunotherapy: a hypothesis.

Allergen Immunotherapy (AIT) is able to restore a physiological Th1 response and Tregs function. This effect is allergen-specific, even though it has been reported that it may also be non-specific, such as also extended to allergens not used in AIT. This immunological phenomenon may also be of clinical nature. This case report shows that a poly-allergic patient, successfully treated with Parietaria extract, also achieved a clinical tolerance towards other causal allergens, such as mites and cat. Of course, this was an anecdote, but it is reasonable to prospect the hypothesis that a bystander clinical effect may be observed during AIT in poly-allergic patients.

Dimerisation increases the immunogenicity of recombinant Parj1/Parj2 allergens.

Purified recombinant Parj1 and Parj2 allergens bind an IgE repertoire common to the Parietaria species, allowing their use as marker molecules for diagnosis and therapy of allergic disease induced by the Urticaceae family. Preclinical studies on the in vivo immunogenicity of recombinant Parj1, Parj2 and their isoforms indicated differential capacity to induce IgG1 antibody responses, as indication of potential clinical use. A recombinant hetero-dimeric hybrid derivative (PjED), encompassing the shorter Parj1 isoform (Parj1.0201) and Parj2 allergen, was characterised. In vivo immunisation with PjED induces IgG1 antibodies capable of binding all the isoforms of Parietaria major allergens, overcoming the poor immunogenicity of single monomeric allergens. This feature makes PjED a promising candidate molecule to be further characterised for clinical applications in the treatment of Parietaria allergy.

An unusual case of occupational asthma in a part time magician. He has got an allergy surprise from his top hat!

In this report we describe a case of respiratory allergy induced by an unusual occupational exposure to rabbit. The patient worked as a part-time magician in theatres and private parties and the most popular performance of his show was to pull out a white rabbit from a top hat. Unfortunately, a few minutes after the extraction of rabbit from top hat, the patient experienced the onset of upper and lower airway symptoms, and in some occasions he was forced to stop the show and to use short acting ß2agonists and intramuscular steroids. The results of SPT and evaluation of serological specific IgE (ImmunoCAP and ImmunoCAP ISAC IgE) revealed allergic sensitization to rabbit (Oryctolagus cuniculus) dander as well as to Parietaria and dust mites. ImmunoCAP ISAC IgE excluded allergic sensitization to other cross-reacting animal allergens. Rabbit constitutes a reliable risk factor for allergic sensitization in individuals working as professional / part-time magicians or as animators in some recreational settings (resorts, parties, charity shows, etc).