Rural and urban exposures shape early life immune development in South African children with atopic dermatitis and nonallergic children

BACKGROUND

Immunological traits and functions have been consistently associated with environmental exposures and are thought to shape allergic disease susceptibility and protection. In particular, specific exposures in early life may have more significant effects on the developing immune system, with potentially long-term impacts.

METHODS

We performed RNA-Seq on peripheral blood mononuclear cells (PBMCs) from 150 children with atopic dermatitis and healthy nonallergic children in rural and urban settings from the same ethnolinguistic AmaXhosa background in South Africa. We measured environmental exposures using questionnaires.

RESULTS

A distinct PBMC gene expression pattern was observed in those children with atopic dermatitis (132 differentially expressed genes [DEGs]). However, the predominant influences on the immune cell transcriptome were related to early life exposures including animals, time outdoors, and types of cooking and heating fuels. Sample clustering revealed two rural groups (Rural_1 and Rural_2) that separated from the urban group (3413 and 2647 DEGs, respectively). The most significantly regulated pathways in Rural_1 children were related to innate activation of the immune system (e.g., TLR and cytokine signaling), changes in lymphocyte polarization (e.g., TH17 cells), and immune cell metabolism (i.e., oxidative phosphorylation). The Rural_2 group displayed evidence for ongoing lymphocyte activation (e.g., T cell receptor signaling), with changes in immune cell survival and proliferation (e.g., mTOR signaling, insulin signaling).

CONCLUSIONS

This study highlights the importance of the exposome on immune development in early life and identifies potentially protective (e.g., animal) exposures and potentially detrimental (e.g., pollutant) exposures that impact key immunological pathways.

Differential diagnosis between urticarial vasculitis and chronic spontaneous urticaria: An international Delphi survey

BACKGROUND

Urticarial vasculitis (UV) should be differentiated from chronic spontaneous urticaria (CSU) in patients initially presenting with recurrent wheals, although criteria for differential diagnosis remain ill-defined.

OBJECTIVES

To set the goals, define criteria and unmet needs in UV diagnosis and differential diagnosis with CSU, and explore the possibility of coexistence of both diseases.

METHODS

Thirteen experts experienced in UV research participated in a Delphi survey of European Academy of Allergy and Clinical Immunology taskforce. This Delphi survey involved three rounds of anonymous responses to n = 32 questions with the aim to aggregate the experts' opinions and to achieve consensus. Urticaria specialists (n = 130, most from Urticaria Centers of Reference and Excellence) evaluated the consensus statements and recommendations in the fourth and final round.

RESULTS

The panel agreed that essential criteria to guide a skin biopsy in patients with recurrent wheals should include at least one of the following features: wheal duration >24 h, bruising/postinflammatory hyperpigmentation, and systemic symptoms. Leukocytoclasia and fibrin deposits were identified as a minimum set of UV histological criteria. As agreed by the panel members, CSU and normocomplementemic UV (NUV) may coexist in some patients.

CONCLUSIONS

The use of established criteria for the diagnosis and differential diagnosis of UV in patients with recurrent wheals can help guide the diagnostic approach and prompt earlier treatment. Further studies should investigate whether CSU and NUV are different entities or part of a disease spectrum.

Risk factors of NSAID-exacerbated respiratory disease: A population-based study

BACKGROUND

Asthma with NSAID-exacerbated respiratory disease (NERD) is associated with uncontrolled or severe asthma. NERD patients are more prone to severe allergic reactions and their asthma exacerbations lead to hospitalisations twice as often compared to patients with non-NERD-asthma. NERD patients are prone to recurrent nasal polyposis requiring frequent endoscopic sinus surgeries. However, the early risk factors of NERD are not fully understood. The aim was to identify risk factors of NERD among patients with adult-onset asthma.

METHODS

We used data from 1350 population-based adult asthmatics with adult-onset asthma from Finnish national registers. NERD was defined as self-reported wheeze or other typical respiratory symptoms after ingestion of NSAIDs. Thirty-six covariates covering several domains (personal characteristics, life-style, early life factors, asthma characteristics and multimorbidities) were selected based on literature and were studied in association with NERD using logistic regressions.

RESULTS

The study population included 153 (11.3%) asthmatics with NERD. Thirty-six covariates were entered in univariate logistic regression analysis, in which 23 were associated with NERD (p < 0.05). These variables were entered in a multivariable logistic regression model in which allergic respiratory symptoms, female sex, osteoarthritis, difficult asthma, nasal polyps, second-hand smoke exposure at home, having 3 or more older siblings and being overweight were significantly associated with asthma with NERD (p < 0.05). Overweight decreased the risk of NERD, other factors increased it.

CONCLUSION

According to our study, risk factors of NERD in part are associated with female sex, BMI, exposure to tobacco smoke, allergy, orthopaedic disorders and infection history, and their early recognition might thus be important to manage the burden of NERD.

Allergenic risk assessment of cowpea and its cross-reactivity with pea and peanut

BACKGROUND

Novel protein sources can represent a risk for allergic consumers. The aim of this study was to evaluate the allergenicity of cowpea (Vigna unguiculata), an increasingly consumed legume and potential new industrial food ingredient which may put legume-allergic patients at risk.

METHODS

Children with allergy to legumes associated to peanut (LP group: n = 13) or without peanut allergy (L group: n = 14) were recruited and sensitization to several legumes including cowpea was assessed by prick tests and detection of specific IgE (sIgE). Cowpea protein extract was analyzed by SDS-PAGE and immunoblotting, IgE-reactive spots were subjected to mass spectrometry. IgE-cross-reactivity between cowpea, pea, and peanut was determined using ELISA inhibition assays. Basophil activation tests were performed to evaluate sensitivity and reactivity of patient basophils toward legumes.

RESULTS

Prick tests and sIgE levels to cowpea were positive in 8/14 and 4/13 patients of the L group and in 9/13 and 10/13 patients of the LP group, respectively. Four major IgE-binding proteins were identified as vicilins and seed albumin. Cowpea extract and its vicilin fraction strongly inhibited IgE-binding to pea and peanut extract. Peanut, lentil, and pea were the strongest activators of basophils, followed by cowpea, soybean, mung bean, and lupin.

CONCLUSION

A majority of patients with legume allergy were sensitized to cowpea proteins. Four novel allergens were identified in cowpea, among which storage proteins were playing an important role in IgE-cross-reactivity, exposing legume-allergic patients to the risk of clinical cross-reactivity to cowpea and thus adding cowpea to the group of nonpriority legumes that are not subjected to allergen labeling such as chickpea, pea, and lentil.

Allergic patients during the COVID-19 pandemic-Clinical practical considerations: An European Academy of Allergy and Clinical Immunology survey

BACKGROUND

The COVID-19 pandemic has affected health care systems unexpectedly. However, data focusing on practical considerations experienced by health care professionals (HCPs) providing care to allergic patients is scarce.

METHODS

Under the framework of the European Academy of Allergy and Clinical Immunology (EAACI), a panel of experts in the field of immunotherapy developed a 42-question online survey, to evaluate real-life consequences of the COVID-19 pandemic in allergy practice.

RESULTS

The respondents in the survey were 618. About 80% of HCPs indicated being significantly affected in their allergy practice. A face-to-face visit reduction was reported by 93% of HCPs and about a quarter completely interrupted diagnostic challenges. Patients with severe uncontrolled asthma (59%) and anaphylaxis (47%) were prioritized for in-person care. About 81% maintained an unaltered prescription of inhaled corticosteroids (ICS) in asthmatics. About 90% did not modify intranasal corticosteroids (INCS) in patients with allergic rhinitis. Nearly half of respondents kept biological prescriptions unmodified for asthma. About 50% of respondents kept their allergen immunotherapy (AIT) prescription patterns unchanged for respiratory allergies; 60% for insect venom allergies. Oral immunotherapy (OIT) for food allergies was initiated by 27%. About 20% kept carrying out up-dosing without modifications and 14% changed to more prolonged intervals. Telemedicine practice was increased.

CONCLUSIONS

HCPs providing care to allergic patients were affected during the pandemic in diagnostic, management, and therapeutic approaches, including AIT for respiratory, insect-venom, and food allergies. Most HCPs maintained controller treatments for both asthma, and allergic rhinitis consistent with international recommendations, as well as biological agents in asthma. Remote tools are valuable in delivering allergy care.