Why is pet (cat/dog) allergen immunotherapy (AIT) such a controversial topic? Current perspectives and future directions.

Summary: Dogs and cats are the most common pets worldwide. In Italy, the prevalence of allergic sensitization to cats and dogs is 16% and 9% respectively. The limited standardization of allergenic extracts, especially for dogs, emphasizes the importance of Component Resolved Diagnosis (CRD) for accurate diagnosis and subsequent prescription of allergen immunotherapy (AIT). However, this low standardization is the main factor contributing to the unsatisfactory clinical efficacy of traditional AIT, AIT with modified allergens, and intralymphatic allergen-specific immunotherapy (ILAIT). Emerging immunological approaches, particularly for controlling the primary cat allergen, show promise but are hindered by high costs (e.g., use of anti-Fel d 1 monoclonal antibodies in humans) or by exclusively targeting Fel d 1 produced by one's own animal (e.g., immunizing cats to induce neutralizing antibodies against Fel d 1 or including an egg product with anti Fel d 1 IgY antibodies in feline diet). Further studies are imperative for standardizing pet allergens, enhancing the efficacy of various AIT modalities, and exploring other immunological approaches, to optimize the relationship between pets and their owners and prevent distressing "forced removals".

COVID-19 lockdown, personal protective equipment, hyper-hygiene and allergy.

Summary: At the beginning of SARS-CoV 2 pandemic, in the absence of "targeted" therapies, the national health authorities have introduced some measures aimed at reducing the spread of infection in the community (lockdown, social distancing, personal protective equipment (PPE), personal hygiene and disinfection of living environments). All the containment measures have led to both positive and negative effects in patients with allergic diseases. We believe that further studies should be undertaken to investigate the possible correlations between SARS-CoV-2 infection and allergy, from a broader perspective. In particular, the risk factors for the development of undesirable effects should be investigated, especially in healthcare professionals forced to use PPE and sanitizing agents for a long time. However, since the COVID-19 pandemic probably will not be short-lived, the use of such protective aids will necessarily be widespread even in the general population. Therefore, further studies on the materials used for the production of PPE and sanitizing agents would be necessary to reduce their sensitizing and, in some cases, toxic potential.

Pharmacology and Therapeutics of Bronchodilators Revisited.

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of ß 2-adrenoceptors (ß 2-ARs) on airway smooth muscle with ß 2-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting ß 2-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

Lessons from peculiar cases of anaphylaxis: why allergists should be prepared for the unexpected.

Summary: Anaphylaxis is the most severe systemic hypersensitivity reaction, it can be caused by a number of well identified triggers such as foods, drugs, stinging insects and facilitated by predisposing clinical conditions. However, sometimes anaphylaxis shows up with uncommon or peculiar characteristics which could delay diagnosis and therapeutic treatment. In this report we aimed to describe less accounted / difficult-to-approach shapes of anaphylaxis to facilitate clinicians to suspect these severe reactions even in uncommon conditions. We choose to present data on anaphylaxis regarding simulation, mode of exposure to sensitizing agents, pregnancy, exposure to animals, intimate behaviour, psychological stress and other situations.

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.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study.

BACKGROUND: The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization. METHODS: Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog. RESULTS: A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported. CONCLUSIONS: Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Dog allergy: can a prevalent or exclusive sensitization to Can f 5 be considered a lucky or negative event in real life?

Summary: Recent studies have shown the increasing relevance of allergic sensitization to Can f 5 (a prostatic kallikrein), which is an androgen-regulated protein expressed in the prostate and detectable only in male dogs. Can f 5 can be a prevalent or exclusive sensitizing agent in a considerable percentage of dog-allergic patients. Its specific allergenic characteristics are able to induce possible negative as well as positive clinical effects in individuals sensitized to dogs. In the present article we pointed out the possible pros or cons of sensitization to this allergen in real life. Further studies should be carried out to correctly assess some peculiar characteristics of Can f 5, in order to support the most of positive aspects and remedy at best the negative effects.

Combining long-acting bronchodilators with different mechanisms of action: A pharmacological approach to optimize bronchodilation of equine airways.

The ultra long-acting ß2 -adrenoceptor agonist olodaterol plus the ultra long-acting muscarinic antagonist tiotropium bromide are known to relax equine airways. In human bronchi combining these drugs elicits a positive interaction, thus we aimed to characterize this information further in equine isolated airways stimulated by electrical field stimulation (EFS) and using the Concentration-Reduction Index (CRI) and Combination Index (CI) equations. The drugs were administered alone and together by reproducing ex vivo the concentration-ratio delivered by the currently available fixed-dose combination (1:1). The single agents elicited a significant (p < .05) concentration-dependent reduction in the EFS-induced contractility, that was synergistically improved (CI 0.18) when administered in combination (0.9 logarithms more potent, 24% more effective than the monocomponents). The drugs mixture allowed a reduction in the concentration of olodaterol from ≃1 to ≃2.3 logarithms. A favorable CRI was detected also for tiotropium bromide, whose concentration can be reduced ≃1 logarithm at medium effect levels, remaining positive up to submaximal relaxant effect in the presence of olodaterol. The combination of tiotropium bromide/olodaterol allows the reduction in the concentration of the monocomponents to achieve airway smooth muscle relaxation, thus potentially decreases the risk of adverse events when these drugs are used to treat severe asthmatic horses.

Letter to the Editor: Can dog allergen immunotherapy reduce concomitant allergic sensitization to other furry animals? A preliminary experience.

Summary: It has been shown that allergen immunotherapy (AIT) is effective in reducing symptoms of allergic asthma and rhinitis. Data on the efficacy are less convincing with regard to AIT for allergens of common pets (cats/dogs). We describe a case of dog allergy in which we explored if dog AIT (DAI) could reduce a concomitant allergic sensitization to other allergens of furry animals. Our case demonstrates the efficacy of sublingual DAI on SPTs, symptom score, and spirometric responses despite persistent exposure to dog allergens at home in a patient sensitized, but not exposed, to several other furry animals. Moreover, this is the first report suggesting that DAI is able to reduce SPTs responses not only to dog, but also to other furry animals such as rabbit, horse, mouse, rat, hamster, cow. We recommend an accurate anamnesis and diagnosis of dog allergy before prescribing DAI. In particular, the use of ImmunoCAP ISAC is essential to verify the presence of IgE to lipocalins / albumins belonging to other furry animals. Obviously further studies carried out by using different DAI schedules, allergen amount and time of re-evaluation, laboratory procedure should be performed to confirm our findings.

Can the presence of cat/dog at home be considered the only criterion of exposure to cat/dog allergens? A likely underestimated bias in clinical practice and in large epidemiological studies.

An important aspect of allergic sensitization to furry animals is the association of dog and cat exposure in early childhood with the incidence of respective allergies later in life. This topic is very controversial, because some authors have found a "facilitating" effect, while others have noticed a "protective" or even no significant effect in individuals living in urban areas. It is likely that some biases could be responsible of these contradictory findings. Cat/dog ownership or their presence in indoor environments are considered usually the main criteria to assess the exposure to these pets in studies' questionnaires. Even in clinical practice "are there animals at home?" is the common query usually done when collecting anamnestic data. In our opinion, these commonly used questions should not be considered the main index of exposure to pet allergens, because they can lead to erroneous interpretation of the clinical significance of positive skin prick tests for pet allergens as well as of the real risk of exposure to allergens of dog/cat in epidemiological studies. Consequently, we suggest a new, more realistic, classification of modalities of exposure to pet allergens in "real life" based on five possible conditions.

Influence of allergic status and nasal polyposis on long-term Benralizumab response in eosinophilic severe asthma.

Objective: It is unclear whether Benralizumab effectiveness in severe eosinophilic asthma can be influenced by nasal polyposis (NP) or allergic status associations. We evaluated whether Benralizumab long-term efficacy in asthma outcomes could be different in subjects with atopy (SAEA) compared to the effectiveness in those without allergies (SNAEA) and in individuals with NP compared to those without NP. Methods: This observational retrospective study considered 95 consecutive patients divided into allergic (SAEA; n:65[68.4%]; skin prick tests positive [SPT] and/or IgE values ≥100 UI/mL), and non-allergic (SNAEA; n:30[31.6%], SPT negative and normal IgE levels<100 UI/mL). Overall population was also divided into two groups according to NP presence (NP+:39[41%] and NP-:56[59%]). Benralizumab treatment mean was19.7±7.2 months (range 12-35). Results: No differences in Benralizumab effectiveness were found in asthma outcomes in patients with/without NP. SNOT-22 improvement was higher in NP+ (-22±24) compared to NP- groups (6.33±15.5;p=0.055). FEV1 (16.33±19.22%), ACT(7.45±3.95) increases and frequency of SABA use (3.37±4.99) reduction were higher in SAEA compared to what obtained in non-allergic subjects (FEV1:8.15±15.6%,p=0.043; ACT:4.89±3.57,p=0.005; SABA use:-1.16±1.84;p=0.015). 93.8% of SAEA patients whereas only 72.2% of SNAEA individuals reduced OC doses at least half after Benralizumab (p=0.035). These results were partially confirmed by linear regression models showing associations between allergic status and FEV1, ACT and SABA use changes (ß=8.37;p=0.048, ß=2.056;p=0.033 and ß=-2.184;p=0.042 respectively). Conclusion: Benralizumab effectiveness in asthma appears to be independent of NP presence. The allergic eosinophilic disease, compared to just eosinophilic asthma, may be a more severe phenotype. Benralizumab may have greater efficacy in SAEA on some outcomes.

Severe asthma and long-term Benralizumab effectiveness in real-life.

OBJECTIVE: Long-term efficacy of Benralizumab in real life is not clearly known. We assessed the long-term effectiveness persistence to anti-IL-5R treatment in a group of severe eosinophilic asthmatics. PATIENTS AND METHODS: We retrospectively analyzed 95 individuals affected by severe asthma (36 males  ̶ 37.9%; mean age 58.1 ± 12.2) treated with Benralizumab (mean time 19.7 ± 7.2 months, range 12-35). Outcomes were evaluated at the beginning and at the end of patients' treatment periods. RESULTS: Mean baseline blood eosinophils were 897.5 ± 720.1 cells/µL (11 ± 5.6%) decreasing to 7.4 ± 20.6 cells/µL (0.97 ± 0.26%; p < 0.0001) after Benralizumab. FENO likewise decreased from 63.9 ± 68.4 to 28.4 ± 23.6 ppb, while FEV1% significantly improved (p < 0.0001). Mean FEF25-75 also increased from 45.8 ± 24.6% to 60.7 ± 24.6%, whereas RAW dropped from 202.15 ± 109.6% to 135.2 ± 54.75% (p < 0.0001). Also, lung volumes greatly decreased. ACT/ACQ significantly improved, while exacerbations number fell from 4.1 ± 2.4, before anti-IL-5R, to 0.33 ± 0.77, after treatment (p < 0.0001). Rhinitis severity levels and SNOT-22 also changed favorably. Patients that took long-term OCs were 71.6% before treatment, decreasing to 23.2% after Benralizumab (p < 0.0001), with an OCs dose reduction from 14.8 ± 8.9 to 1.45 ± 2.8 mg/day (p < 0.0001). 51.6% of subjects used SABA as needed before Benralizumab, falling to 4.2% after treatment. Several patients showed a reduction of ICS doses, SABA use and maintenance therapy step-down. Clinical/biological response with anti-IL-5R remained constant or even improved in terms of exacerbations or maintenance therapy reductions over time. On the contrary, FEF25-75% improvement slowed down in the long-term. No relationship was found between baseline blood eosinophil number and therapeutic response. CONCLUSIONS: Long-term Benralizumab effectiveness persistence in all outcomes in real life was confirmed.