Measurement is an essential activity in the field of allergy and due to the subjective nature of the results that are being measured, it is increasingly necessary to have valid, reproducible, and reliable methods. There are some reviews or task forces that present different methods or techniques to develop a validation study, which may cause some confusion. With this review, we intend to bring together and synthesize some of the information found, to help researchers and clinicians to interpret or understand the varied nomenclature read in the literature. Before any data collection, a translation of the questionnaire is needed. Psychometry involves the application of statistical techniques to test the measurement properties of an instrument. There are several measures to evaluate an instrument, the main ones being: classical test theory and modern test theory. Regarding the classical test theory, the key psychometric characteristics are scale structure, accuracy (validity), precision (reliability) and responsiveness. Modern test theory models are techniques to assess the psychometric characteristics of an instrument, focused on the dimensionality of the questionnaire. Responsiveness, validity, and precision are interlinked. Following these steps ensures the development of validated questionnaires that provide valuable insights into allergy prevalence, impact, and management.

Background: Increasing evidence are available about the presence of increased serum concentration of Immunoglobulin (Ig) Free Light Chains (FLCs) in both atopic and non-atopic inflammatory diseases, including severe asthma, providing a possible new biomarker of disease, disease severity and also an alternative approach to the treatment. Methods: We analyzed clinical and laboratory data, including FLCs, obtained from a cohort of 79 asthmatic subjects, clinically classified into different GINA steps. A control group of 40 age-matched healthy donors (HD) was considered. Particularly, HD have been selected according to the absence of monoclonal components (in order to exclude paraproteinemias), were tested for total IgE (that were in the normal ranges) and were negative for aeroallergens specific IgE. Moreover, no abnormality of common inflammatory markers (i.e. erythrocyte sedimentation rate, C-reactive protein) was detectable. Results: FLC-k levels were significantly increased in the asthmatic population, compared to the control group. Despite the absence of statistically significant differences in FLC-λ levels, the FLC-k/FLC-λ ratio displayed remarkable differences between the two groups. A positive correlation between FLC-κ and FLC-λ levels was found. FLC- λ level displayed a significant negative correlation with the FEV1 value. Moreover, the FLC-κ /FLC- λ ratio was negatively correlated with the SNOT-22 score and a positive correlation was observed between FLCs and Staphylococcus Aureus IgE enterotoxins sensitization. Conclusions: Our findings confirmed the role of FLCs in asthma as a potential biomarker in an inflammatory disease characterized by different endotypes and phenotypes. In particular, FLC-κ and FLC-k/FLC-λ ratio could be a qualitative indicator for asthma, while FLC-λ levels could be a quantitative indicator for disease severity.

Background: Several biologics are now available as add-on treatment for severe asthma but, currently there are no universally accepted criteria to measure the response to these therapies. This survey aims to establish consensus criteria to use in practice for the initial evaluation of response to biologics after four months of treatment. Method: Using Delphi methodology, a questionnaire including ten items was developed and validated by a 13-member panel of international experts in asthma. The electronic survey circulated within the INterasma Scientific Network platform, Global Asthma Association membership, contact list of the co-authors, national associations for specialists, and social media. For each item, five answers were proposed graduated from “no importance” to “very high importance” and by a score (A=2 points; B=4 points; C=6 points; D=8 points; E=10 points). The final criteria were selected if the median score for the item was ≥7 and >60% of responses accorded “high importance” and “very high importance”. All selected criteria were validated by the thirteen experts. Results: Four criteria were identified to evaluate the efficacy of biologics in asthma: to reduce daily systemic corticosteroids dose by ≥50% (ideally complete withdrawal); to decrease the number of asthma exacerbations requiring systemic corticosteroids by ≥50%, (ideally no asthma exacerbation); to have no/minimal side-effects and to obtain asthma control according validated questionnaires. The consensual decision was that ≥3 criteria are needed to conclude a good response to biologics. Conclusions: Specific criteria were defined by an international panel of experts and could be used as tool in clinical practice.

Asthma is a chronic inflammatory airway disease resulting in airflow obstruction, which in part can become irreversible to conventional therapies, defining the concept of airway remodeling. The introduction of biologics in severe asthma has led in some patients to the complete normalization of previously considered irreversible airflow obstruction. This highlights the need to distinguish a “fixed” bronchial obstruction due to structural changes unresponsive to current therapies, from a “reversible” one as demonstrated by lung function normalization during biological therapies not previously obtained even with high dose systemic glucocorticoids. The mechanisms by which exposure to environmental factors initiates the inflammatory responses that trigger airway remodeling are still incompletely understood. Alarmins represent tissue-derived cytokines that initiate immunologic events leading to inflammatory airway remodeling. Biological therapies can improve airflow obstruction by addressing these airway inflammatory changes. In addition, biologics might prevent and possibly even revert “fixed” remodeling due to structural changes. Hence, it appears clinically important to separate the therapeutic effects (early and late) of biologics as a new paradigm to evaluate the effects of these drugs and future treatments on airway remodeling in severe asthma.

Immune modulation is a key therapeutic tool for allergic diseases and asthma. It can be achieved in an antigen-specific way via allergen immunotherapy (AIT) or in endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: IgE, IL-5 and IL-4/IL-13. COVID-19 vaccine provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. It works as well through immune modulation. Thus, as there is an obvious interference between these treatment modalities recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) gathered an outstanding expert panel under its Research and Outreach Committee (ROC). This expert panel was called to evaluate the evidence and formulate recommendation on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals.

Although there is a considerable body of knowledge about allergen immunotherapy (AIT), there is a lack of data on the reliability of real-world evidence (RWE) in AIT and consequently, a lack of information on how AIT effectively works in real life. To address the current unmet need for an appraisal of the quality of RWE in AIT, the European Academy of Allergy and Clinical Immunology Methodology Committee recently initiated a systematic review of observational studies of AIT, which will use the RELEVANT tool and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) to rate the quality of the evidence base as a whole. The next step will be to develop a broadly applicable, pragmatic “real-world” database using systematic data collection. Based on the current RWE base, and perspectives and recommendations of authorities and scientific societies, a hierarchy of RWE in AIT is proposed, which places pragmatic trials and registry data at the positions of highest level of evidence. There is a need to establish more AIT registries that collect data in a cohesive way, using standardised protocols. This will provide an essential source of real-world data that can be easily shared, promoting evidence-based research and quality improvement in study design and clinical decision-making.