This systematic review evaluates the efficacy, safety and economic impact of dupilumabcompared to standard of care for uncontrolled moderate-to-severe atopic dermatitis (AD). Pubmed, EMBASE and Cochrane Library were searched for RCTs and health economic evaluations. Critical and important AD-related outcomes were considered. The risk of bias and the certainty of the evidence were assessed using GRADE. Seven RCTs including 1845 subjects > 12 years treated with dupilumab16 to 52 weeks were evaluated. For adultsthere is high certainty that dupilumabdecreasesSCORAD (MD -30,72; 95%CI -34,65% to -26,79%) and EASI-75 (RR 3.09; 95%CI 2.45 to 3.89), pruritus (RR 2.96; 95%CI 2.37 to 3.70), rescue medication (RR 3.46; 95%CI 2.79 to 4.30), sleep disturbance (MD -7.29; 95%CI -8.23 to -6.35), anxiety/depression (MD -3.08; 95% CI -4.41 to -1.75) and improves quality of life (MD -4.80; 95% CI -5.55 to -4.06). The efficacy for adolescents is similar. Dupilumab-related adverse events (AEs) slightly increase (low certainty). The evidence for dupilumab-related serious AE is uncertain. The incremental cost-effectiveness ratio ranged from 28,500 £ (low certainty) to 124,541 US$ (moderate certainty).More data on long term safety are needed both for children and adults, together with more efficacy data in the paediatric population.

Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers. It has led to the development of nanomaterials, which behave very differently compared with materials with larger scales and can be applied in a wide range of applications in biomedicine. The physical and chemical properties of materials of such small compounds depend mainly on the size, shape, composition, and functionalisation of the system. Nanoparticles, carbon nanotubes, liposomes, polymers, dendrimers, nanogels, among others, can be nanoengineeried for controlling all parameters, including their functionalisation with ligands, which provide the desired interaction with the immunological system. However, undesired issues related to their toxicity and hypersensitivity responses have impeded more rapid health applications. Through interactions with the immune system, some of these nanostructures show promising applications as vaccines and diagnostics tools. Dendrimeric Antigens, Nanoallergens, and nanoparticles are potential tools for the in vitro diagnosis of allergic reactions. Glycodendrimers, liposomes, polymers, and nanoparticles have shown interesting applications in immunotherapy. There are wide panels of structures accessible, and controlling their physico-chemical properties would allow the obtainment of safer and more efficient compounds for clinical applications goals, either in diagnosis or treatment.

To the Editor, Severe asthma (SA) is a chronic disease affecting around 3-8% of adult asthma population in Europe, with the refractory form estimated to occur in 0.1% of the general population (1,2). SA is characterized by increased use of healthcare resources (i.e. emergency room/hospital admissions, access to intensive care units (ICU), use of biologics) due to exacerbations compared to the less severe form. In the current SARS-CoV-2 pandemic, there is an ongoing debate on the role of asthma and use of immunomodulating drugs, like corticosteroids and biologics, on COVID-19 outcomes. According to available data on COVID-19 hospitalizations, asthma seems to play little role on the clinical severity or access to health resources, unlike other chronic conditions such as hypertension, obesity and chronic obstructive pulmonary disease (3). However, to date, no information is available on the burden of SA on COVID-19 severity and hospitalization rates.A questionnaire was submitted to the Italian Registry of Severe Asthma (IRSA) network (4), assessing the prevalence and clinical characteristics of patients with SA who contracted COVID-19 during the outbreak in Italy (February 24th - May 18th 2020), and 41 out of 78 centers distributed evenly among different Italian regions participated to the survey (Figure 1a).Among the 558 subjects surveyed, 7 subjects contracted COVID-19 (1.25% of the national sample), with an average age of 54.5 years: 5 isolated at home/received home care (71.5%), while 2 subjects were admitted to the hospital (28.5%), none required accessed to ICU and no deaths were reported. All COVID-19 subjects with SA came from 2 regions of Northern Italy (6 Lombardy, 1 Emilia-Romagna, 3.7% of the regional population), all showing one or more comorbidities, and were treated with high-dose inhaled corticosteroids plus long-acting beta-2 agonists (ICS-LABA) and biologics (see Table 1).We then compared our results with data provided by the Italian Department for Civil Protection in the same time period from the affected geographic areas (5), and we observed that the frequency of COVID-19 among subjects referred to IRSA centers strongly correlated with the prevalence of SARS-CoV-2 infection in the corresponding province (Figure 1b). Furthermore, the hospitalization rate in COVID-19-SA subjects was not significantly different from the general population (24.1%, 23.6-24.6 95% C.I.; p=0.25, Chi-squared test). Lastly, we could not observe a significantly increased COVID-19 frequency in subjects undergoing high-dose ICS-LABA and biologics compared to SA treated with ICS-LABA alone (p=0.09, Fisher exact test).These findings from the IRSA registry offer some insights on the susceptibility to SARS-CoV-2 infection, access to healthcare resources and mortality by SA patients.Given the low prevalence of SA in Italy (2), we expected less COVID-19-SA cases per region than what reported by the IRSA survey. However, we observed that the geographic location of COVID-19-SA patients mostly reflected the bimodal distribution of the COVID-19 outbreak in Italy, mainly clustered in Lombardy and neighboring regions, where the highest cumulative COVID-19 cases were recorded (>500/100000 cases per inhabitants) (5). In these areas, the prevalence of positive cases by province also strongly correlated with the frequency of COVID-19-SA patients observed in each IRSA center (Figure 1b), suggesting that patients with SA most likely contract the infection when high circulation of the virus within the area of residence is present. The lack of positive cases reported in Southern regions further proves this hypothesis, and demonstrates the efficacy of the lockdown measures adopted to contain the further spread of the virus.Our results also suggest no increased risk of contracting COVID-19 in SA treated with biologics compared to ICS-LABA alone. Although there is currently no strong evidence that biologics used in asthma might affect the risk of contracting COVID-19, new evidence suggests a protective effect of inhaled corticosteroids against viral entry by ACE2 receptor downregulation, that are usually prescribed at a high dose in SA (6), thus a possible explanation to the lack of observed differences in our cohort.Despite the severity of asthma and reported comorbidities, no ICU admissions were reported, and hospital admissions in COVID-19-SA subjects did not differ from the median rate observed in the same geographic areas (5). Furthermore, we could observe no difference in the median monthly hospitalization rate of SA patients in 2019 compared to 2020 in Lombardy region where both hospital-admitted subjects reside (0.97 vs 0.9%, IRSA data).Our result is consistent with recent literature, showing that asthma in Western countries was not associated with an increased hospitalization rate and ICU admissions due to COVID-19 (3,8). It is still debated if a protective effect of Th2-inflammation in a significant proportion of asthma sufferers (7), or concomitant anti-inflammatory therapy could be the reasons for such outcomes (6). However, if asthma patients with COVID-19 require intubation, the duration of hospitalization was shown to be longer than average (8).As for the role of biologics in COVID-19 disease progression, we could not observe an increase in hospital admissions in patients with SA treated with biologics compared to the general population, with the majority isolating at home and requiring no additional treatment. Considering that, in areas with high prevalence of SARS-CoV-2 infection, 68.2% of SA subjects were treated with either omalizumab or mepolizumab, our observations further prove the safety of biologics during the COVID-19 pandemic.Lastly, we did not observe any deaths in our cohort, but we speculate that this outcome is most likely due to the small sample size and younger average age. In fact, advanced age seems to be the most determining risk factor on mortality due to COVID-19 compared to other causes. (9)Taken together, our results point at a neutral role of SA in the COVID-19 disease course and hospital admissions. One major strengths of our study is that, by using a fast and inexpensive tool, we could outline the salient features of severe asthma and COVID-19 at a national level, while the major weakness is the limited number of SA subjects diagnosed with COVID-19, that could lead to sampling bias and low accuracy. Further confirmation of these results with an increased sample size is therefore warranted

To the Editor Since the end of February 2020 Italy, first non- Asian Country, has reported an ever increasing number of COronaVIrus Disease 19 (COVID-19) patients, which has reached over 200,000 confirmed Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) infected subjects and resulted in more than 34000 deaths (data updated to June 19th, 20201).Patients with asthma are potentially more severely affected by by SARS-CoV-2 infection 2 and it is well established that respiratory viral infections are associated with severe adverse outcomes in patients with asthma, including increased risk of asthma exacerbation episodes 3. Nonetheless, according to the epidemiological studies published so far, chronic pulmonary diseases are not amongst the most common clinical conditions in COVID-19 patients4About 5-10% of entire asthma population, are severe asthmatics5 and one would expect increased vulnerability to SARS-CoV-2 infection, but no data is so fare available ti confirm this hypothesis.We investigated the incidence of COVID-19, describing its clinical course, in the population of the Severe Asthma Network in Italy (SANI), one of the largest registry for severe asthma worldwide6, and in an additional Center (Azienda Ospedaliero Univeristaria di Ferrara, Ferrara, Italy). All centers, have been contacted and inquired to report confirmed (i.e. patients with positive test result for the virus SARS-CoV-2 from analysis of nasopharyngeal or oropharyngeal swab specimens) or highly suspect cases of COVID-19 (i.e. patients with symptoms, laboratory findings and lung imaging typical of COVID-19 but without access to nasopharyngeal or oropharyngeal swab specimens because of clinical contingencies/emergency) among their cohorts of severe asthma. Demographic and clinical data of the entire cohort of severe asthmatics enrolled in the study and all reported cases of confirmed or suspect cases of COVID-19, have been obtained from the registry platform and collected from the additional Center. Additional data about COVID-19 symptoms, treatment and clinical course have been collected for all cases reported.Ethical issues and statistical analysis are reported in the online supplementary material.Twenty-six (1.73%) out of 1504 severe asthmatics had confirmed (11 out of 26) or highly suspect COVID-19 (15 out 26); eighteen (69.2%) were females and mean age was 56.2 ± 10 years. The geographical distribution of COVID-19 cases is presented in Figure 1.Nine (34.6%) infected patients experienced worsening of asthma during the COVID-19 symptomatic period; four of them needed a short course of oral corticosteroids for controlling asthma exacerbation symptoms.The most frequent COVID-19 symptoms reported were fever (100% of patients), malaise (84.6%), cough (80.8%), dyspnea (80.8%), headache (42.3%) and loss of smell (42.3%). Four patients (15.3%) have been hospitalized, one of which in intensive care unit; among hospitalized patients, two (7.7%) died for COVID-19 interstitial pneumonia. No deaths have been reported among the non-hospitalized patients.Severe asthmatics affected by COVID-19, had a significantly higher prevalence of non-insulin-dependent diabetes mellitus (NIDDM) compared to non-infected severe asthma patients (15.4% vs 3.8%, p=0.002; odds ratio: 4.7). No difference was found in other comorbidities (including rhinitis, chronic rhinosinusitis with or without nasal polyps, bronchiectasis, obesity, gastroesophageal reflux, arterial hypertension, cardiovascular diseases).Twenty-one patients with COVID-19 were on biological treatments: 15 (71%) were on anti-IL-5 or anti-IL5R agents (Mepolizumab n= 13; Benralizumab n=2 - counting for the 2.9% of all severe asthmatics treated with anti-IL5 in our study population) and 6 (29%) were on anti IgE (Omalizumab - 1.3% of all severe asthmatics treated with omalizumab in our study population).Table I summarizes demographic and clinical characteristics of the 26 COVID-19 patients.In conclusion, in our large cohort of severe asthmatics, COVID-19 was infrequent, not supporting the concept of asthma as a particularly susceptible condition to SARS-COV2 infection 2. This is in line with the first published large epidemiological data on COVID-19 patients, in which asthma is under-reported as comorbidity4. The COVID-19 related mortality rate in our cohort of patients was 7.7%, lower than the COVID-19 mortality rate in the general population (14.5% in Italy 1). These findings suggest that severe asthmatics are not at high risk of the SARS-CoV-2 infection and of severe forms of COVID-19. There are potentially different reasons for this. Self-containment is the first, because of the awareness of virus infections acting as a trigger for exacerbations, and therefore they could have acted with greater caution, scrupulously respecting social distancing, lockdown and hygiene rules of prevention, and being more careful in regularly taking asthma medications.Another possible explanation stands in the intrinsic features of type-2 inflammation, that characterizes a great proportion of severe asthmatics. Respiratory allergies and controlled allergen exposures are associated with significant reduction in angiotensin-converting enzyme 2 (ACE2) expression 7, the cellular receptor for SARS-CoV-2. Interestingly, ACE2 and Transmembrane Serine Protease 2 (TMPRSS2) (another protein mediating SARS-CoV-2 cell entry) have been found highly expressed in asthmatics with concomitant NIDDM8, the only comorbidity that was more frequent reported in our COVID-19 severe asthmatics.The third possible explanation refers to the possibility that inhaled corticosteroids (ICS) might prevent or mitigate the development of Coronaviruses infections. By definition, patients with severe asthma are treated with high doses of ICS 5 and this may have had a protective effect for SARS-CoV-2 infection.Noteworthy, among the patients of our case-series of severe asthmatics with COVID-19, the proportion of those treated anti-IL5 biologics was higher (71%) compared to the number of patients treated with anti-IgE (29%). Although the number of cases is too small to draw any conclusion, it is tempting to speculate that different biological treatments can have specific and different impact on antiviral immune response. In addition we may speculate of the consequence of blood eosinophils reduction: eosinopenia has been reported in 52-90% of COVID-19 patients worldwide and it has been suggested as a risk factor for more severe COVID-19 9.In conclusion, in our large cohort of severe asthmatics only a small minority experienced symptoms consistent with COVID-19, and these patients had peculiar clinical features including high prevalence of NIDDM as comorbidity. Further real-life registry-based studies are needed to confirm our findings and to extend the evidence that severe asthmatics are at low risk of developing COVID-19.

Reply to Morais-Almeida.To the Editor,We appreciate Dr. Morais-Almeida’s comments 1 about our Letter to the Editor, presenting additional literature about asthma prevalence in severe COVID-19 patients and highlighting data that contrasts our hypothesis that asthma, particularly type 2 asthma, may be protective against severe disease.The data that protection may be dependent on type 2 immunity is derived from the higher percentage of asthmatics being atopic2, also reflected in the series of ~2,500 patients regularly followed up in our Allergy Unit. Yu et al. 3 provided preliminary evidence about this in a single-center retrospective study, where COVID-19 atopic patients had less severe infections, milder lung damage compared to age- and gender- matched COVID-19 controls.ACE-2, the SARS-CoV-2 receptor, is linked to type 1 and 2 interferon signatures, and found to be overexpressed in type 2-low asthmatics4. Nevertheless, different outcomes in distinct asthma phenotypes still need to be addressed in COVID-19 studies.Besides Italy and China, reports from Russia 5 on ~1,300 intensive care unit patients with SARS-CoV-2 infection confirm the observation of a low prevalence of chronic lung diseases (i.e. asthma as well as COPD).Although preliminary data on the first COVID-19 cases in the US6 seem to contrast these observations, the higher prevalence of asthma in US COVID-19 hospitalised patients should be considered alongside a higher overall prevalence in these countries compared to Europe and China, as well as on the influence of other comorbidities (i.e. obesity) and host factors (i.e. age, race: 33% were non-Hispanic black patients in the study by Garg et al.) impacting COVID-19 outcomes. Another report from Sweden 7highlights the association between severe asthma and severe COVID-19.The severe asthma phenotype is often characterized by mixed granulocytic populations (neutrophilic and eosinophilic), prevalent type 1 inflammation, increased IFN-γ levels in the airways and ineffectiveness of ICS. This severe phenotype by itself, although accounting for less than 5% of asthmatic patients, would justify the CDC (and other institutions) including asthma as a risk factor for COVID-19. Data from the UK 8, apart from confirming the role of additional comorbidities, draw attention to the recent use of oral steroids, which, indeed, may be a clue for uncontrolled and/or severe asthma.Uncontrolled asthma is a risk factor for viral exacerbations and hospitalizations and we embrace the opportunity to stress the importance of optimal adherence to asthma controlling medications, regular follow-up and specialist-assessment of disease activity. Moreover, treatable comorbidities, which may impair asthma control, should always be managed. Promoting vaccination for preventable respiratory infections (i.e. Influenza and Pneumococcal pneumonia) is also advisable. Future studies may help better distinguishing the impact of different asthma phenotypes and comorbidities on COVID-19 outcome.Carli G.1, Cecchi L.1, Stebbing J.2, Parronchi P.3, Farsi A.11 SOS Allergy and Clinical Immunology, USL Toscana Centro, Prato Italy2 Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK3 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy

The “coronavirus disease 2019 (COVID-19)” outbreak was first reported in December 2019 (China). Since then, this disease has rapidly spread across the globe and in March 2020 the World Health Organization (WHO) declared the COVID-19 pandemic.1 Since the outbreak was first announced, our journal has extensively focused on the clinical features, outcomes, diagnosis, immunology, and pathogenesis of COVID-19 and its infectious agent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We published our first COVID-19 article on 19 February, focusing for the first time on the clinical characteristics of 140 cases of human-to-human coronavirus transmission without any links to the Huanan Wet Market.2 Hypertension and diabetes were mentioned as risk factors and there was no increased prevalence in allergic patients. This early study reported that the main symptoms at hospital admission were fever (91.7%), cough (75.0%), fatigue (75.0%), gastrointestinal symptoms (39.6%), and dyspnea (36.7%). Lymphopenia and eosinopenia were also reported as important signs and biomarkers for monitoring and severity of the patients.2 The prevalent eosinopenia in COVID-19 patients and the possible anti-viral role of eosinophils were further discussed in several following publications inAllergy .3,4 Our second COVID-19 paper brought attention to the wide range of clinical manifestations of this disease, from asymptomatic cases to patients with mild and severe symptoms, with or without pneumonia as well as with only diarrhea.5Patients with common allergic diseases did not develop distinct symptoms and severe courses. Cases with pre-existing chronic obstructive pulmonary disease or complicated with a secondary bacterial pneumonia were severe. Another article, timely appearing in our journal, alerted the scientific community that even in experienced hands there was a 14.1% false negative polymerase chain reaction (PCR) diagnosis in COVID-19 cases and were later diagnosed positive after repeated tests.6 A pediatric article was also published extensively analyzing 182 cases and it was reported that children with COVID-19 showed a mild clinical course.7 Patients with pneumonia had a higher proportion of fever and cough and increased inflammatory biomarkers compared to those without pneumonia. There were 43 allergic patients in this series and there was no significant difference between allergic and non-allergic COVID-19 children in disease incidence, clinical features, laboratory, and immunological findings. Allergy was not a risk factor for disease and severity of SARS-CoV-2 infection and did not significantly influence the disease course of COVID-19 in children.7The immunology of COVID-19 was extensively reviewed in two articles from leading experts with a comprehensive discussion of the tip of the iceberg in COVID-19 epidemiology, anti-viral response, antibody response to SARS-CoV-2, acute phase reactants, cytokine storm, and pathogenesis of tissue injury and severity. 8,9Two studies timely reported the role of possible trained immunity in countries with a Bacillus Calmette-Guérin (BCG) vaccination programme and a relatively low COVID-19 prevalence and mortality rate.10,11 In an extensive RNA sequencing analyses of SARS-CoV-2 receptor and their molecular partners revealed that ACE2 and TMPRSS2 were coexpressed at the epithelial sites of the lung and skin, whereas CD147 (BSG), cyclophilins (PPIA and PPIB), CD26 (DPP4) and related molecules were expressed in both, epithelium and in immune cells.12Allergists, respiratory physicians, pediatricians, and other health care providers treating patients with allergic diseases are frequently in contact with patients potentially infected with SARS-CoV-2. Practical considerations and recommendations given by experts in the field of allergic diseases can provide useful recommendations for clinical daily work. Since the beginning of this current pandemic, our journal has disseminated clinical reports, 2,3,5,6,13 statements on the urgent need for accuracy in designing and reporting clinical trials in COVID-19,14 preventive measures,10,11,15 and Position Statements elaborated by experts in the field in close collaboration with the European Academy of Allergy and Clinical Immunology (EAACI) and its task force “Allergy and Its Impact on Asthma (ARIA) ”.16-28 (keynote information in table 1). A compendium answering 150 frequently encountered questions regarding COVID-19 and allergic diseases has been recently published by experts in their respective area.29 In addition, readers can put further questions regarding this “living ” compendium electronically to the authors and their answers will be available through a new category in the journal’s webpage.30Besides, EAACI in collaboration with ARIA, has provided recommendations on operational plans and practical procedures for ensuring optimal standards in the daily clinical care of patients with allergic diseases, whilst ensuring the safety of patients and healthcare workers.23Table 1: Examples of recently published recommendations, statements and Position Papers of the EAACI

Dear Editor,we read with great interest the article recently published by Morishima L et al. (1 ). The Authors report an high incidence of Anisakis-specific IgE antiboides in patients with anaphylaxis in two towns in Japan.Worlwide the incidence of Anisakis patients is related to the ingestion of raw fish in seaside places. Herein we present the case of a child who has experienced an anaphylaxis with acute respiratory symptoms and a strange scrotal mass, in Calabria, a region completely surrounded by the sea in Southern Italy.An 8-year-old child italian child referred to our Emergency Department with a clinical complaint characterized by acute respiratory distress and right testicular pain since almost 24 hours, that worsened during the day. The respiratory picture resolved almost immediately with the use of corticosteroids via i.v. The clinical examination showed the presence of a painful testicle-independent swelling of about 1 cm in diameter, between the perineal plane and the scrotum, in the absence of signs of inflammation.The doppler ultrasonography demonstrated the presence of phlogistic area at the level of the right epididymis. We decide for home observation and medical therapy (betamethasone and amoxy-clavulanic acid) with mild improvement in symptoms in the following 3 days.After 4 days the child came back to our attention with an important scrotal lymphadenitis consensual to the previous epididymitis, with erythematous and warm scrotal skin. The intense scrotal pain, as in a clinical picture of acute scrotum, did not allow to visit the boy correctly.A second US showed an independent mass from the testicle of about 1 cm.The laboratory findings were completely negative, including testicular markers for tumour.The formula was; white blood cells 5.800, Neutrophiles 48.9%, Lymphocytes 41.8%, Eosinophils 0.8%. At surgical exploration the testicle was normal and a paratesticular granulomatous mass of about 2 cm in diameter was removed.The section of the anatomical specimen in the operatory room left us speechless.Inside the operating specimen we found … Worms! The histological examination confirmed a case of extra-gastrointestinal anisakiasis.

Background This systematic review used the GRADE approach to compile evidence to inform an anaphylaxis guideline from the European Academy of Allergy and Clinical Immunology (EAACI). Methods We searched five bibliographic databases from 1946 to 20 April 2020 for studies about the diagnosis, management and prevention of anaphylaxis. We included 50 studies with 18,449 participants: 29 randomised controlled trials, seven controlled clinical trials, seven consecutive case series and seven case-control studies. Findings were summarised narratively because studies were too heterogeneous to conduct meta-analysis. Results It is unclear whether the NIAID/FAAN criteria or Brighton case definition are valid for immediately diagnosing anaphylaxis due to the very low certainty of evidence. Adrenaline is the cornerstone of first-line emergency management of anaphylaxis but, due to ethical constraints, little robust research has assessed its effectiveness . Newer models of adrenaline autoinjectors may slightly increase the proportion of people correctly using the devices and reduce time to administration. Face-to-face training for laypeople may slightly improve anaphylaxis knowledge and competence in using autoinjectors. Adrenaline prophylaxis prior to snake bite anti-venom may reduce anaphylaxis but the impact of prophylactic corticosteroids and antihistamines is uncertain. There was insufficient evidence about the impact of other anaphylaxis management strategies. Conclusions Anaphylaxis is a potentially life-threatening condition but, due to practical and ethical challenges, there is a paucity of robust evidence about how to diagnose and manage it.

In past ten years, microRNAs (miRNAs) have gained scientific attention due to their importance in the pathophysiology of allergic diseases and their potential as biomarkers in liquid biopsies. They act as master post-transcriptional regulators that control most cellular processes. As one miRNA can target several mRNAs, often within the same pathway, dysregulated expression of miRNAs may alter particular cellular responses and contribute or lead to the development of various diseases. In this review, we give an overview of the current research on miRNAs in allergic diseases, including atopic dermatitis, allergic rhinitis and asthma. Specifically, we discuss how individual miRNAs function in the regulation of immune responses in epithelial cells and specialized immune cells in response to different environmental factors and respiratory viruses. In addition, we review insights obtained from experiments with murine models of allergic airway and skin inflammation and offer an overview of studies focusing on miRNA discovery using profiling techniques and bioinformatic modelling of the network effect of multiple miRNAs. In conclusion, we highlight the importance of research into miRNA function in allergy and asthma to improve our knowledge of the molecular mechanisms involved in the pathogenesis of this heterogeneous group of diseases.

Background. Lymphocyte transformation test (LTT) has been widely used to evaluate non-immediate drug hypersensitivity reactions (NIDHRs). However, the lack of standardisation and the low sensitivity have limited its routine diagnostic use. The drug presentation by dendritic cells (DCs) and the assessment of proliferation on effector cells have shown promising results. Flow-cytometry-based methods can help apply these improvements. We aimed to assess the added value of using drug-primed-DCs and the determination of the proliferative response of different lymphocyte subpopulations in NIDHRs. Methods. Patients with confirmed NIDHR were evaluated by both conventional (C-LTT) and with drug-primed-DCs LTT (dDC-LTT) analysing the proliferative response in T-cells and other effector cell subpopulations by using the fluorescent molecule, carboxyfluorescein diacetate succinimidyl ester. Results. The C-LTT showed a significantly lower sensitivity (33.3%) compared with dDC-LTT (65.2%), which was confirmed analysing each particular clinical entity: SJS-TEN (62.5% vs 87.5%), MPE (14.3% vs 41.7%), and AGEP (33% vs 80%). When including the effector cell subpopulations involved in each clinical entity, CD3++CD4+Th1 cells in SJS-TEN, CD3++CD4+Th1+NK cells in MPE, and CD3++NK cells in AGEP, we could significantly increase the sensitivity of the in vitro test to 100%, 66.6%, and 100%, respectively. With an overall sensitivity of 87% and 85% of specificity in NIDHR. Conclusions. The use of a flow-cytometry-based test, DCs as drug presenting cells, and focussing on effector cell subpopulations for each clinical entity significantly improved the drug-specific proliferative response in NIDHRs with a unique cellular in vitro test.

To the Editor,We read carefully the research letter “Is asthma protective of COVID-19?” by Carli et al recently published.1Important topic for asthma patients in the coronavirus disease 2019 (COVID-19) pandemic were considered, including that until recently weak evidence that patients with chronic respiratory disorders are at a lower risk of being infected or becoming severely ill with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).Reflecting only about previous reports from China and Italy where asthma was underrepresented in COVID-19 patients, the authors accept the heterogeneous condition that it is asthma, speculating that T2-immunity, interferon-mediated immune responses and increased number of eosinophils in the airways could have a protective effect against COVID-19 severity.1The epidemiology of COVID-19 is changing rapidly with new data. More recent reports from the United States of America and from several European countries, in particular the United Kingdom (UK), states a higher asthma prevalence in patients with COVID-19, suggesting that asthma is more common in COVID-19 patients than it was previously reported in Asia and in the first European surveys.2Data from the UK Biobank, a large prospective case-control study, found an asthma prevalence of 17,9% in 605 COVID-19 hospitalized patients, mostly of them adults, surpassing the prevalence of asthma in the general population.3Besides that, in the OpenSAFELY Collaborative Study (UK), it was found a significant increased risk of severe CoViD-19 in patients with asthma, including death, in particular related with the recent use of oral corticosteroid (OCS).4 These findings can indicate an increased asthma severity and/or poor control and, in accordance with data from previous coronavirus outbreaks, that systemic corticosteroids were associated with a higher viral load.5We agree with Carli et al1 that further studies focused on asthma and its different phenotypes are needed to provide a better understanding of the impact of SARS-CoV-2 infection in patients with asthma.6 Nevertheless, for the moment, it seems crucial that patients with asthma do not stop their controller medication, that may lead to a higher risk of asthma exacerbations, increased OCS use and higher probability to emergency room access and hospitalization that represent themselves significant risk factors for coronavirus exposure and spread.In conclusion, according with the available data, patients with asthma must still be included in the high-risk groups for COVID-19 and more data are needed to understand the relationship between asthma and COVID-19.

The pandemic condition Coronavirus-disease (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can take asymptomatic, mild, moderate, and severe courses. COVID-19 affects primarily the respiratory airways leading to dry cough, fever, myalgia, headache, fatigue, and diarrhea and can end up in interstitial pneumonia and severe respiratory failure. Different clinical symptoms caused by involvement of organs outside the respiratory system have been also described. Interestingly, reports about the manifestation of various skin lesions and lesions of the vascular system in some subgroups of SARS-CoV-2 positive patients as such features outside the respiratory sphere, are rapidly emerging. However, knowledge about prevalence and pattern of skin involvement, time of onset, predilection, and its direct or indirect relation to SARS-CoV-2 is still limited. In order to update information gained, we provide a systematic overview of the skin lesions described in COVID-19 patients, discuss potential causative factors and describe differential diagnostic evaluations.

Background Currently, the coronavirus disease 2019 (COVID-19) has become pandemic globally. 10-20% of the cases are severe and more than 397,000 deaths have occurred. The risk factors for the mortality of critically ill COVID-19 patients remain to be elucidated. Conclusions Survived severe and non-survived COVID-19 patients had distinct clinical and laboratory characteristics, which were separated by principle component analysis. Logistic regression revealed several risk factors such as elder age, greater affected lobe numbers and higher level of serum CRP for the mortality of severe COVID-19 patients. Longitudinal changes of laboratory findings indicate the advancement of the disease and may be helpful in predicting the progression of severe patients.

Asthma control, self-management and healthcare access during the COVID-19 Epidemic in BeijingChun Chang a* M.D., Linlin Zhanga*B.S., Fawu Dong a* B.S., Ying Liang a M.D., Yahong Chen a M.D., Ying Shang a B.S., Mairipaiti Abulikemua B.S., Yongchang Suna# M.D.aDepartment of Respiratory and Critical Care Medicine, Peking University Third Hospital, Beijing, China.#, Corresponding to Yongchang Sun:Department of Respiratory and Critical Care Medicine, Peking University Third Hospital, Beijing, China.North Garden Rd. 49.Haidian District, Beijing, 100191, ChinaTel: +86 010 139 1097 9132Fax +86 108 226 6989E-mail: [email protected]* Chun Chang, Linlin Zhang and Fawu Dong contributed equally to this work;To the Editor:The pandemic of COVID-19, caused by the pathogen SARS-CoV-2, has now spread around the globe. Social distancing and restriction measures during COVID-19 pandemic may have impacts on asthma control and management in terms of medication availability and healthcare access. International societies responded quickly by releasing guidance on the management of asthma during the COVID-19 pandemic1-4. However, these temporary guidelines were based largely on previous asthma guidelines and expert consensus, because evidence from related studies was lacking. Therefore, we investigated the status of asthma control, self-management, medications and healthcare utilization of asthma patients during the COVID-19 epidemic in Beijing, aiming to provide data for guideline recommendations on asthma managements during the emergency.Patients with asthma, selected randomly from our hospital database, were interviewed by phone call. Detailed description of items in the questionnaire is available in this article’s online supplementary material.We contacted 286 patients, of whom 178 (62.2%) responded with valid results. Sociodemographic data and clinical characteristics of the patients before the COVID-19 pandemic are provided as online supplements. During the COVID-19 epidemic in Beijing (January 25, 2020 to April 25, 2020), the majority (74.2%, 132/178) of the patients felt that their symptoms had not changed as compared with usual times, while 18.0% (32/178) felt better, and 7.9% (14/178) felt worse. The mean ACT score of the 178 patients was 22.76 ± 3.06 (ranging from 8 to 25) in the last 4 weeks before the survey. According to the criteria of ACT scoring from GINA, asthma was classified as well-controlled in 89.3%, not well-controlled in 6.2%, and very poorly controlled in 4.5% of the patients. During this period, only 24.7% (44/178) of the patients had ever visited a hospital or clinic for asthma, of whom 11 patients had 2 visits, and 6 had ≥3 visits, totaling 74 visits. 14.9% (11/74) of all medical visits were due to exacerbation of asthma, while the remaining visits (63/74, 85.1%) were for regular prescription of asthma medications. Only 6 patients (3.4%) sought consultation online. (Table 1)Notably, 25.6% (45/176) of the patients experienced aggravation of asthma symptoms during the COVID-19 epidemic, but 75.6% (34/45) of them did not see a doctor, because 67.6% (23/34) of the patients thought that they did not need to go to the hospital and took more medications by themselves, and the remaining 32.4% (11/34) worried about cross-infection of COVID-19 in the hospital. No patient said that they did not see a doctor because they could not arrange an appointment. Eleven patients went to the hospital due to aggravation, 81.8% (9/11) to the outpatient, while only 18.2% (2/11) to the Emergency Department (ED).Table 1 Asthma control and management during the COVID-19 epidemic in Beijing

Atopic diseases have increased in prevalence over the last few decades and the rapid increases suggest that the predominant driving forces behind these increases are environmental factors rather than genetic alterations. A number of environmental factors have been implicated in the increased prevalence of allergic diseases. Predominant among them are increased exposure to pollutants and decreased exposure to microbes and parasitic infections. The hygiene hypothesis suggests that increased hygiene and lack of exposure to microbes and parasitic infections at an early age prevents the necessary stimulus to train the developing immune system to develop tolerogenic responses. Lifestyle factors, such as increased time spent indoors, use of antibiotics, and consumption of processed foods and decreased exposure to farm animals and pets, limit exposure to environmental allergens, infectious parasitic worms, and microbes. The lack of exposure to these factors is thought to prevent proper education and training of the immune system. Other factors that are also associated with increased risk of allergic diseases are Caesarian birth, birth order, tobacco smoke exposure and psychosomatic factors. Here, we review current knowledge on the environmental factors that have been shown to affect the development of allergic diseases and the recent developments in the field.

Brain activation after nasal histamine provocation in house dust mite allergic rhinitis patientsCallebaut I1, Steelant B1, Backaert W1, Peeters R2-3, Sunaert S2-3, Van Oudenhove L4-5*, Hellings PW1*1Allergy and Clinical Immunology Research Group, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium2Department of Imaging & Pathology, KU Leuven, Leuven, Belgium3Department of Radiology, University Hospitals Leuven, Leuven, Belgium4Laboratory for Brain-Gut Axis Studies (LaBGAS), Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism, and Ageing (CHROMETA), University of Leuven, Belgium5Cognitive and Affective Neuroscience Laboratory (CANlab), Center for Cognitive Neuroscience, Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA*Joined senior authorshipTo the editor . The nasal mucosa is armed with a complex nervous system of sensory, sympathetic and parasympathetic nerves, allowing swift defensive responses to physical and chemical stimuli. In allergic rhinitis (AR) patients, nasal allergen deposition leads to mast cell activation with release of allergic mediators such as histamine. Apart from its direct effects on the surrounding tissue, histamine also activates sensory nerve endings giving rise to symptoms like sneezing, rhinorrhoea, and/or congestion(1). Activated nasal sensory nerves transmit action potentials to their cell bodies in the trigeminal ganglion and further to the midbrain where secondary synapses lead to the generation of central reflex signals. Despite activation of neural pathways in AR(2), it is not known which particular regions in the brain are activated by different nasal stimuli. Clinical studies using Positron Emission Tomography scans indicate that there is no isolated itch center in the brain but that different cortical centers are involved in the processing of itch(3, 4). Activation of the anterior cingulate cortex (ACC), the supplementary motor area (SMA), and the inferior paretial lobe partly explains the connection between itching and the related reflex of scratching(4). Using functional magnetic resonance imaging (fMRI), the activation of the superior temporal gyrus, insula and nucleus caudate following painful intranasal trigeminal stimulation has been shown(5). When asthmatic patients are challenged with metacholine or allergens, activity in ACC and insula was associated with markers of bronchial inflammation and obstruction(6).To fill the abovementioned knowledge gap, a prospective, single-blind, cross-over study was designed to investigate brain responses to nasal histamine provocation in healthy volunteers and AR patients.Eight house dust mite (HDM) AR patients and 7 non-allergic healthy controls (HC) were recruited at the outpatient clinic for Otorhinolaryngology of University Hospitals Leuven. HDM allergy was confirmed by a skin prick test. Relevant nasal anatomic abnormalities or rhinosinusitis were ruled out by nasal endoscopy. Non-allergic HC showed a negative skin prick test for all the tested allergens, showed no nasal symptoms and had normal nasal endoscopy. Patients of <18 and >50 years of age, having used nasal or oral steroid treatment <6weeks prior to the study or nasal or oral antihistamine treatment <4weeks prior to the study were excluded, as well as those with past or ongoing immunotherapy for HDM, asthma, smoking and clinical signs of rhinosinusitis or anatomic nasal deformities. Informed consent was signed by all participants. The study was approved by the local medical ethics committee of the University Hospitals Leuven (B322201215751).All HC and AR patients underwent a nasal provocation by means of a canulla placed under the nose with either nebulized sham solution (saline) or with histamine for 5 minutes while in supine position in the MR scanner on 2 separate days with a minimum of 1 week in between, and in a single-blinded and random order. An aerosol of 10 ml histamine HCl (16 mg/ml) or 10 ml saline was delivered via the canulla by means of air (8 bar) after 10 minutes of baseline scanning in a pharmacological (ph)MRI design. This concentration of histamine was chosen as optimal dose after a pilot study in 3 HCs, 1 birch and grass pollen AR patient and 1 HDM AR patient where the dose of histamine resulted in a reduction of 20% in the Peak Nasal Inspiratory Flow (PNIF). Moreover, patients did not had the urge to sneeze at this concentration, as was the case for the dose of 32 mg/ml.PNIF values were used for measuring nasal flow at baseline and after the nasal provocation at the end of the phMRI scan, as recommended(7). The best value out of three consecutive measurements with a variability of <10% was recorded. Changes in PNIF from baseline to post-provocation were compared between conditons (histamine & saline) as well as between groups (patients & controls) using marginal linear mixed models.phMRI data were preprocessed and analyzed as described previously(8, 9). The effect of interest for the present study was the group (patient versus controls)-by-substance (histamine versus saline)-by-time interaction effect, comparing the time-course of the brain response to histamine vs saline provocation between AR patients and controls. A whole-brain voxel-wise FWE-corrected threshold of p<0.05 was used combined with an extent threshold of k=10 voxels (corresponding to pFWE<0.001 at cluster level).In total, 8 HDM AR patients (5 females and 3 males) and 7 HC (5 females and 2 males) were recruited with a mean age of 22.5 ± 0.72 and 23.8 ± 1.11 years respectively. One female HDM AR and two female HC were excluded due to excessive head movement during MR scanning.After nasal provocation with saline, no significant decrease in PNIF was found compared to baseline in both groups (AR: 135 ± 61.82 l/min vs 137.5 ± 44.88 l/min, p=0.74; HC: 120 ± 36.74 vs 129 ± 31.30, p=0.46). Nasal provocation with histamine induced a significant decrease in PNIF in both HDM AR patients (158.8 ± 71.55 l/min vs 112.5 ± 83.67, p=0.0053) as well as in the HC (134.2 ± 27.64 l/min vs 85.83 ± 40.55, p=0.002).The analysis on PNIF values showed a significant condition-by-time (pre- to post-provocation) interaction effect (F(1,11)=28.8, p=0.0002), driven by a significant decrease in PNIF after histamine (-47.30±8.87, pHolm=0.0004), but not after saline (-5.81±5.96, pHolm=0.35) in the entire sample. No significant group-by-condition-by-time interaction effect was found (F(1,11)=0.09, p=0.78) indicating that the decrease from baseline after histamine compared to saline did not differ between patients and controls, with a significant decrease from baseline after histamine but not saline in both groups (p=0.002 and p=0.015, respectively).Brain regions showing a differential response to histamine versus saline in AR patients versus HCs included bilateral mid-/posterior insula, right anterior insula, bilateral postcentral/superior temporal gyrus/rolandic operculum (including secondary somatosensory cortex), bilateral putamen, left cerebellum (crus 1 & 2), right mid-occipital gyrus, bilateral medial orbital gyrus/gyrus rectus, and right middle/superior frontal gyrus (ventrolateral prefrontal cortex) (Table 1,Figure 1). Most of these differential responses were due to a stronger activation in controls vs AR patients, except for the right anterior insula, right middle occipital gyrus, right middle/superior frontal gyrus, and left cerebellum, where a stronger activation was observed in AR patients.

In December 2019, China reported the first cases of the coronavirus disease 2019 (COVID-19). This disease, caused by the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), has developed into a pandemic. To date it has resulted in ~5.6 million confirmed cases and caused 353,334 related deaths worldwide. Unequivocally, the COVID-19 pandemic is the gravest health and socio-economic crisis of our time. In this context, numerous questions have emerged in demand of basic scientific information and evidence-based medical advice on SARS-CoV-2 and COVID-19. Although the majority of the patients show a very mild, self-limiting viral respiratory disease, many clinical manifestations in severe patients are unique to COVID-19, such as severe lymphopenia and eosinopenia, extensive pneumonia, a “cytokine storm” leading to acute respiratory distress syndrome, endothelitis, thrombo-embolic complications and multiorgan failure. The epidemiologic features of COVID-19 are distinctive and have changed throughout the pandemic. Vaccine and drug development studies and clinical trials are rapidly growing at an unprecedented speed. However, basic and clinical research on COVID-19-related topics should be based on more coordinated high-quality studies. This paper answers pressing questions, formulated by young clinicians and scientists, on SARS-CoV-2, COVID-19 and allergy, focusing on the following topics: virology, immunology, diagnosis, management of patients with allergic disease and asthma, treatment, clinical trials, drug discovery, vaccine development and epidemiology. Over 140 questions were answered by experts in the field providing a comprehensive and practical overview of COVID-19 and allergic disease.

Medical Algorithm: Early Introduction of Food Allergens in High Risk PopulationsHelen R Fisher,1,2 Gideon Lack,1,2,3 Graham Roberts,4,5,6 Henry T Bahnson,7 George Du Toit.1,2,31Paediatric Allergy Group, Department of Women and Children’s Heath, School of Life Course Sciences, King’s College London, London, United Kingdom2Paediatric Allergy Group, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom.3Children’s Allergy Service, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom.4The David Hide Asthma and Allergy Research Centre, St Mary’s Hospital, Newport, UK.5NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.6Faculty of Medicine, Clinical and Experimental Sciences, Human Development in Health Academic Units, University of Southampton, Southampton, UK.7Immune Tolerance Network, Benaroya Research Institute, Seattle, WashingtonCorresponding Authour:Professor George Du ToitPaediatric AllergyBlock B, South WingSt Thomas’ HospitalLondonSE1 7EHTel: 0207 188 9784Email: [email protected] Count: 602Tables: 0Figures: 1Oral Tolerance Induction (OTI) is the only RCT-proven effective intervention for preventing childhood food allergy.(1) OTI to peanut is effective in a general population, with the greatest effect, 81% RRR, noted in the high-risk population.(2) OTI also reduced egg allergy in the general population.(1) Many governmental and allergy societies now recommend introducing peanut in infancy and some suggest other foods, such as well-cooked egg, are also introduced. Choosing which infants should undergo OTI, at what age, to which foods, and under which circumstances is critical for successful OTI prevention in populations where food allergy is a public health concern.Infants with eczema are at increased risk of food allergy but infants from the general population are also at risk and contribute most cases at a population level. Risk of food sensitisation or food allergy increase with age; OTI is most likely to be successful when started in early infancy. Oral tolerance induction from 4 months of age, when completed using standard foods, is safe for nutrition, growth and general child health outcomes (3). Commencing multiple food OTI at 4 months of age, has no detrimental effect on established breastfeeding.(4) All children should adopt a diverse weaning diet, including allergenic foods such as well-cooked egg and peanut, as soon as weaning commences. High risk children should not delay weaning but start weaning and actively include peanut and well-cooked egg, as soon as developmentally ready; usually at about 4 months of age (Fig 1).A 2g/week dosing regime of peanut and well-cooked egg in early infancy is more effective in inducing oral tolerance than later introduction.(5) A lower dosing regime has not been shown to be effective in preventing allergy but, importantly, does not increase allergy risk above that of children who introduce allergenic foods in later infancy.(4) There are limited data regarding the efficacy of OTI to other allergenic foods, or the dose required.(1) All infants should aim to consume about 2g of peanut protein and well-cooked egg per week; parents of high-risk infants should give these amounts more diligently. Given the benefit observed for peanut and egg, it is reasonable for all weaning infants to additionally incorporate 2g of other common and nutritious food allergens; cow’s milk (e.g. as yoghurt), wheat, fish and sesame.Whether children should undergo allergy testing and/or have their first feed of peanut under medical supervision is contested. This cautious approach, potentially requiring large numbers of children to access specialist allergy care, must be balanced against the risks of severe allergic reaction, particularly as most allergic reactions occur on first oral exposure. RCTs of OTI using whole foods had no cases of anaphylaxis on first exposure (4, 6) although anaphylaxis has occurred to OTI using pasteurised whole egg powder.(7) Children with no personal food allergy risk factors do not require testing prior to, or medical supervision during, their first consumption of peanut or well-cooked egg. Children with moderate to severe eczema, or with an existing food allergy should undergo allergy testing +/- OFC at a specialist allergy centre(8), if doing so would not cause undue delay to OTI. It is likely that rapid access to allergy services will be further compromised as a consequence of the COVID-19 pandemic. It may however be that access to SpIgE is available through GP or paediatrician which, if ≥0.35KiU/L, will require referral for OFC. If negative (<0.35KiU/L) the food may be introduced at home following precautionary measures for the first feed: child is well; parent is aware of the signs of IgE mediated reaction has, access to medical support if required and age-appropriate form of the food is given incrementally (Figure 1).