Personalized medicine for allergy treatment: Allergen immunotherapy still a unique and unmatched model.

The introduction of personalized medicine (PM) has been a milestone in the history of medical therapy, because it has revolutionized the previous approach of treating the disease with that of treating the patient. It is known today that diseases can occur in different genetic variants, making specific treatments of proven efficacy necessary for a given endotype. Allergic diseases are particularly suitable for PM, because they meet the therapeutic success requirements, including a known molecular mechanism of the disease, a diagnostic tool for such disease, and a treatment blocking the mechanism. The stakes of PM in allergic patients are molecular diagnostics, to detect specific IgE to single-allergen molecules and to distinguish the causative molecules from those merely cross-reactive, pursuit of patient's treatable traits addressing genetic, phenotypic, and psychosocial features, and omics, such as proteomics, epi-genomics, metabolomics, and breathomics, to forecast patient's responsiveness to therapies, to detect biomarker and mediators, and to verify the disease control. This new approach has already improved the precision of allergy diagnosis and is likely to significantly increase, through the higher performance achieved with the personalized treatment, the effectiveness of allergen immunotherapy by enhancing its already known and unique characteristics of treatment that acts on the causes.

Personalized medicine and allergen immunotherapy: the beginning of a new era?

The concept of personalized medicine as a diagnostic and therapeutic approach tailored to the medical needs of each patient is currently revolutionizing all fields of medicine and in particular allergology. Allergen immunotherapy (AIT) meets the three main needs for precision medicine: identification of molecular mechanism of disease, diagnostic tools for the mechanism and treatment blocking the mechanism itself. AIT adapts to the spectrum of specific IgE of each individual subject, changing the course and natural history of the disease, so is a clear model of precision and personalized medicine. This first step before the prescription of AIT is to define the sensitization profile of the patient; after that, the healthcare professional has numerous levers for adapting the treatment to the physio-pathological mechanisms involved. AIT allows to adapt treatments to the profile of the patients, but also to the its preferences, to ensure optimal treatment efficacy, resulting in an agile and personalized approach, with the aim to ensure adherence to the treatment, which is usually quite low. AIT also broadens the field of possibilities for healthcare professionals and patients, by allowing to choose the galenic formulation according to patient preferences and on the basis of their clinical history, adapting the product composition to the patient's sensitization profiles and the underlying biological mechanisms identified at the diagnostic stage, while guaranteeing quality of the prescribed product as the production of allergens and allergoids is today more regulated than in the past years. In the management of AIT, it is also possible to involve patients in decisions throughout their care pathway thanks to multiple services, offering personalized follow-up and support, to ensure the highest treatment efficacy levels, and recalling medication intake, medical appointments and prescription renewals.

IR (index of reactivity)-house dust mite sublingual immunotherapy liquid formulation for allergic rhinoconjunctivitis: Systematic review and meta-analysis of randomized and nonrandomized studies.

Background: Although randomized controlled trials (RCT) are the reference standard of evidence in allergen immunotherapy (AIT), nonrandomized studies (NRS) are needed to confirm their results in more representative populations, particularly for treatment duration and persistence. However, when discrepancies are observed between RCT and NRS, NRS reliability decreases because these discrepant results are generally attributed to the methodologic flaws of NRS. Objective: We compared the benefit of sublingual AIT (SLIT) for allergic rhinoconjunctivitis in NRS versus RCT focusing on a single product/allergen to reduce heterogeneity. Methods: For meta-analysis, house dust mite (HDM) SLIT liquid formulation studies were sourced from computerized (Medline, Web of Science, and LILACS databases, to January 2023) and manual literature searches. Populations, treatments, and outcome data were combined (DerSimonian-Laird method). Noncomparative NRS were compared to RCT' SLIT arm before and after treatment. Efficacy was determined as the standardized mean difference (SMD) in symptom score (SS) and medication score (MS). Results: Data from 12 NRS (682 patients) and 8 RCT (176 patients) were analyzed. The benefit with index of reactivity (IR)-HDM SLIT liquid formulation was found significant for, first, SS in both NRS (SMD = -1.27; 95% confidence interval [CI], -1.64, -0.90) and RCT (SMD = -0.56; 95% CI, -0.90, -0.21), and second, MS with SMD equal to -1.35 (95% CI, -1.77, -0.93) and -0.46 (95% CI, -0.67, -0.25), respectively. Metaregression showed that symptom improvement was correlated with treatment duration with consistent results in NRS and RCT with 12-month SS data: -0.87 (interquartile range, -1.02, -0.77) and -0.75 (interquartile range, -0.93, -0.41), respectively. Conclusion: This meta-analysis showed comparable clinical benefit of IR-HDM SLIT liquid formulation increasing over time in both NRS and RCT, suggesting that NRS may reliably integrate RCT results and be considered for guidelines.

Impact of liquid sublingual immunotherapy on asthma onset and progression in patients with allergic rhinitis: a nationwide population-based study (EfficAPSI study).

Background: The only disease-modifying treatment currently available for allergic rhinitis (AR) is allergen immunotherapy (AIT). The main objective of the EfficAPSI real-world study (RWS) was to evaluate the impact of liquid sublingual immunotherapy (SLIT-liquid) on asthma onset and evolution in AR patients. Methods: An analysis with propensity score weighting was performed using the EfficAPSI cohort, comparing patients dispensed SLIT-liquid with patients dispensed AR symptomatic medication with no history of AIT (controls). Index date corresponded to the first dispensation of either treatment. The sensitive definition of asthma event considered the first asthma drug dispensation, hospitalisation or long-term disease (LTD) for asthma, the specific one omitted drug dispensation and the combined one considered omalizumab or three ICS ± LABA dispensation, hospitalisation or LTD. In patients with pre-existing asthma, the GINA treatment step-up evolution was analysed. Findings: In this cohort including 112,492 SLIT-liquid and 333,082 controls, SLIT-liquid exposure was associated with a significant lower risk of asthma onset vs. control, according to all definitions (combined: HR [95% CI] = 0.62 [0.60-0.63], sensitive: 0.77 [0.76-0.78], and specific: 0.67 [0.61-0.72]). Exposure to SLIT was associated with a one-third reduction in GINA step-up regardless baseline steps. Interpretation: In this national RWS with the largest number of person-years of follow-up to date in the field of AIT, SLIT-liquid was associated with a significant reduction in the risk of asthma onset or worsening. The use of three definitions (sensitive or specific) and GINA step-up reinforced the rigorous methodology, substantiating SLIT-liquid evidence as a causal treatment option for patients with respiratory allergies. Funding: Stallergenes Greer.

A successful linkage of a named patient products of sublingual immunotherapy-dispensing registry to French healthcare insurance database (SNDS): methodological constitution of the EfficAPSI cohort.

BACKGROUND: The only causal treatment for allergic rhinitis (AR) is allergen immunotherapy (AIT) including personalized liquid sublingual AIT (SLIT). We present the methodology for establishing the EfficAPSI cohort to further evaluate the real-life effectiveness and use of SLIT liquid. RESEARCH DESIGN AND METHODS: The EfficAPSI cohort was constituted by deterministic linkage of Stallergenes Greer dispensing and nationwide French healthcare insurance system (SNDS) databases. Data from 2006 to 2018 were extracted. All patients who initiated Stallergenes Greer SLIT liquid between 2010 and 2013 were considered as exposed and those dispensed with AR symptomatic treatment only as control. To limit the impact of confounding, the models will be weighted using the inverse probability of treatment weighting (IPTW). RESULTS: A total of 445,574 patients were included; median age was 38 years; 59.1% were female. Exposed patients (n = 112,492) were significantly younger, more frequently males, and less likely to have comorbidities than controls (n = 333,082). After IPTW, patients' characteristics from both groups were similar. CONCLUSIONS: To date, the EfficAPSI cohort has the largest number of person-years of follow-up in the field of AIT. The completeness of the data allows to evaluate SLIT liquid effectiveness with rigorous methodology, leading to important insights on personalized medicine in real-life.

Deciphering Differential Behavior of Immune Responses as the Foundation for Precision Dosing in Allergen Immunotherapy.

Like in many fields of medicine, the concept of precision dosing has re-emerged in routine practice in allergology. Only one retrospective study on French physicians' practice has addressed this topic so far and generated preliminary data supporting dose adaptation, mainly based on experience, patient profile understanding and response to treatment. Both intrinsic and extrinsic factors shape the individual immune system response to allergen immunotherapy (AIT). Herein, we focus on key immune cells (i.e., dendritic cells, innate lymphoid cells, B and T cells, basophils and mast cells) involved in allergic disease and its resolution to further understand the effect of AIT on the phenotype, frequency or polarization of these cells. We strive to discriminate differences in immune responses between responders and non-responders to AIT, and discuss the eligibility of a non/low-responder subset for dose adaptation. A differential behavior in immune cells is clearly observed in responders, highlighting the importance of conducting clinical trials with large cohorts of well-characterized subjects to decipher the immune mechanism of AIT. We conclude that there is a need for designing new clinical and mechanistic studies to support the scientific rationale of dose adaptation in the interest of patients who do not properly respond to AIT.

The MaDo real-life study of dose adjustment of allergen immunotherapy liquid formulations in an indication of respiratory allergic disease: Reasons, practices, and outcomes.

Sublingual allergen immunotherapy (SLIT) is a safe, effective, disease-modifying treatment for moderate-to-severe respiratory allergies. The function and responsiveness of the immune system components underlying the effects of allergen immunotherapy may vary from one patient to another. Furthermore, the severity of the symptoms of allergic disease can fluctuate over time, due to changes in environmental allergen exposure, effector cell responsiveness, and cell signaling. Hence, the allergen dose provided through SLIT can be fine-tuned to establish an optimal balance between effectiveness and tolerability. The objective of the MaDo study was to describe and understand dose adjustments of SLIT liquid formulations in France. We performed a retrospective, observational, cross-sectional, real-life study of allergists and other specialist physicians. Physicians described their patients via an anonymous case report form (CRF). The main patient inclusion criteria were age 5 years or over, at least one physician-confirmed IgE-driven respiratory allergy, and treatment for at least 2 years with one or more SLIT liquid preparations. A nationally representative sample of 33 specialist physicians participated in the study. The physicians' main stated reasons for dose adjustment were adverse events (according to 90.9% of the physicians), treatment effectiveness (60.6%), sensitivity to the allergen (42.4%) and other characteristics (30.3%: mainly symptom severity, type of allergen, and asthma). 392 CRFs (mean ± standard deviation patient age: 27.8 ± 17.5; under-18s: 42.1%; polyallergy: 30.9%) were analyzed. Respectively 53.6%, 25.8%, 15.3%, and 8.7% of the patients received house dust mite, grass pollen, birch pollen and cypress pollen SLIT. Dose adjustments were noted in 258 (65.8%) patients (at the start of the maintenance phase for 101 patients (39.2%) and later for 247 (95.7%)). Dose adjustment was not linked to sex, age, or the number of allergens administered. All measures of disease severity (including symptom severity noted on a 0-to-10 visual analogue scale by the physician) decreased significantly during SLIT. Notably, the mean AR symptom severity score decreased to a clinically relevant extent from 7.6 at SLIT initiation to 2.4 at last follow-up, and the mean asthma symptom severity score decreased from 5.0 to 1.3. The few differences in effectiveness between patients with vs. without dose adjustment were not major. For about one patient in five, a specialist physician decided to reduce or increase the SLIT liquid dose at the start of maintenance treatment and/or during maintenance treatment. This decision was influenced by a broad range of patient and treatment factors, mainly to improve tolerability to treatment and/or enhance effectiveness. In France, dose adjustment of SLIT liquid preparations as a function of the patient profile and/or treatment response is anchored in clinical practice. Precision dosing might optimize the overall benefit-risk profile of AIT for individual patients throughout their entire treatment course, enabling them to achieve both short- and long-term treatment goals, whilst maximizing the safety and tolerability.

Sublingual immunotherapy in children with allergic polysensitization.

Polysensitization is quite frequent in allergic children and may cause difficulties for the allergist in prescribing allergen-specific immunotherapy. This study aimed at evaluating the clinical effectiveness of 1 year of sublingual immunotherapy (SLIT) in a cohort of Italian allergic children with polysensitization. This open study was performed on 51 polysensitized children (34 boys; mean age, 11.8 years; range, 5.2-17.7 years) with allergic rhinitis and/or mild to moderate asthma. All of them were treated with SLIT for 1 year. The kind and the number of prescribed allergen extracts, the type of diagnosis, the severity of symptoms, and the use of drugs were evaluated at baseline and after 1 year. The adverse events to SLIT were also evaluated. Forty-two children were treated with a single extract, four with two different extracts and three with a mix of allergens. SLIT treatment induced a significant reduction in the number of sensitizations (p = 0.018); significant improvement of allergic rhinitis classification and severity; significant reduction of ocular, nasal, and bronchial symptoms (p < 0.01 for all); and drugs use (p < 0.01 for all drugs). No systemic reactions to SLIT were observed. This open study provides evidence that polysensitization is not an obstacle for prescribing SLIT in polysensitized children. Indeed, SLIT efficacy on clinical parameters is significant after 1 year and the therapy is safe.

Specific immunotherapy by the sublingual route for respiratory allergy.

Specific immunotherapy is the only treatment able to act on the causes and not only on the symptoms of respiratory allergy. Sublingual immunotherapy (SLIT) was introduced as an option to subcutaneous immunotherapy (SCIT), the clinical effectiveness of which is partly counterbalanced by the issue of adverse systemic reactions, which occur at a frequency of about 0.2% of injections and 2-5% of the patients and may also be life-threatening. A large number of trials, globally evaluated by several meta-analyses, demonstrated that SLIT is an effective and safe treatment for allergic rhinitis and allergic asthma, severe reactions being extremely rare. The application of SLIT is favored by a good compliance, higher than that reported for SCIT, in which the injections are a major factor for noncompliance because of inconvenience, and by its cost-effectiveness. In fact, a number of studies showed that SLIT may be very beneficial to the healthcare system, especially when its effectiveness persists after treatment withdrawal because of the induced immunologic changes.

Updating on the pathogenic mechanisms 5 of the antiphospholipid antibodies-associated pregnancy loss.

Anti-phospholipid antibodies (aPL) are risk factor for recurrent pregnancy loss and obstetrical complications. The mechanisms of aPL-mediated pregnancy failure are still a matter of research. Although aPL are associated with thrombosis, thrombotic events cannot explain all the miscarriages. There is evidence for a direct in vitro aPL effect on the trophoblast as shown by their binding; reduction of proliferation, human chorionic gonadotrophin release, in vitro invasiveness, adhesion molecule expression; and increased apoptosis. Such a direct reactivity is supported by the expression of beta2 glycoprotein (beta 2GP) I on trophoblast cell membranes. aPL/anti-beta 2GPI antibodies also bind to human decidual/endometrial cells in vitro and induce a pro-inflammatory phenotype. APL-mediated inflammatory processes at the placental level are apparently responsible for fetal loss at least in animal models. Both complement activation and pro-inflammatory cytokine/chemokine secretion have been shown to play a role. More recently, complement-induced tissue factor expression on infiltrating neutrophils was described as an additional pathogenic mechanisms mediated by aPL. As a whole, these findings do suggest that aPL may induce a defective placentation by acting at different levels without involving necessarily thrombotic events.

I405V polymorphism of the cholesteryl ester transfer protein (CETP) gene in young and very old people.

This study was designed to analyse the prevalence of I405V polymorphism in the cholesteryl ester transfer protein (CETP) gene, the CETP serum concentration, the lipoprotein profile, and certain clinical end-points in two populations, one young and another of very old people. We recruited 100 healthy young people (median age 31 years) and 100 very old people (median age 89 years) and analysed their DNA for the presence of I405V polymorphism. The frequency of the VV genotype in very old people was more than double that in the young population. Subjects with this genotype had lower serum concentrations of CETP. Young people with the V/V genotype had a less atherogenic lipoprotein profile (lower total cholesterol, LDL cholesterol, Apo B, and Apo B/Apo A-I ratio) than those with the I/V or I/I genotypes. The older subjects, particularly the older women with the V/V genotype, had larger LDL than the young people. The prevalence of clinical endpoints was much lower among the very old people with the V/V genotype. In conclusion, the V/V genotype of the I405V CETP polymorphism is more frequent among very old people than young ones, and is associated with a lower incidence of vascular damage.

[I405V polymorphism of the cholesteryl ester transfer protein gene in young and very old individuals]. / Il polimorfismo I405V del gene della proteina di trasferimento degli esteri del colesterolo nei giovani e nei grandi vecchi.

This study was designed to analyze the prevalence of I405V polymorphism in the cholesteryl ester transfer protein (CETP) gene, the blood CETP concentration, the lipoprotein pattern and certain clinical endpoints in two populations, one of young and another of very old individuals. We recruited 100 healthy young adults (median age 31 years) and 100 very old subjects (median age 89 years) and analyzed their DNA for the presence of variants V and I of the CETP gene. Subjects with the V/V genotype had lower serum concentrations of CETP. The frequency of this genotype in the very old was more than double that in the young population. Young adults with the V/V genotype had a less atherogenic lipoprotein pattern [lower total and LDL cholesterol levels, lower apolipoprotein (Apo) B levels, and a lower Apo B/Apo A-I ratio] than those with the I/V or I/I genotypes. The very old subjects, particularly those with the V/V genotype, had larger LDL than the young adults. The prevalence of clinical endpoints was much lower among the very old subjects with the V/V genotype.

+874(T-->A) single nucleotide gene polymorphism does not represent a risk factor for Alzheimer's disease.

In the recent years, several cytokines have been associated with Alzheimer's disease (AD) development and progression and many studies have correlated this risk with polymorphisms in the genes encoding these molecules. Also the type 1 cytokine interferon (IFN)-gamma belongs to a cytokine class that affects the immune function; in fact it plays a major role in defence against viruses and intracellular pathogens but also in the induction of the immune-mediated inflammatory response. The aim of this study was to evaluate the role of IFN-gamma in AD by studying the association of +874T-->A IFN-gamma gene polymorphism with AD. We included in this study 115 AD patients (70 women, 45 men, mean age 80) and 90 sex and age-matched healthy controls (HC, 51 women, 39 men, mean age 82) from northern Italy. Genomic DNA was extracted with the salting-out method from whole blood of all subjects; the genotyping at IFN-gamma loci was assessed with ARMS-PCR. The data obtained from the +874T-->A IFN-gamma gene polymorphism analysis of AD patients and HC lack of any statistically significant differences also when stratified according to gender. In conclusion these results confirm the previous shown lack of association between +874T-->A IFN-gamma gene polymorphism and the risk of AD. However, other polymorphisms have been demonstrated to influence IFN-gamma transcription and since natural killer cells of AD patients show higher production of the cytokine, further analysis will be necessary to clarify the role of this gene in the pathogenesis of the disease.

Requirements for acquiring a high-quality house dust mite extract for allergen immunotherapy.

The house dust mite is a major cause of respiratory allergy worldwide. The management of mite allergy is based on avoidance measures, drug treatment, and allergen immunotherapy, but only allergen immunotherapy is able to modify the natural history of the disease. Injectable subcutaneous immunotherapy was introduced a century ago, while sublingual immunotherapy was proposed in the 1980s and emerged in the ensuing years as an effective and safe option to subcutaneous immunotherapy. However, the quality of the extracts to be used in allergen immunotherapy is crucial for the success of treatment. The mite extract for sublingual immunotherapy known as Staloral 300 was developed to offer optimal characteristics concerning the mite culture medium, standardization, and allergen dose. Double-blind, placebo-controlled trials with Staloral 300 have provided a substantial part of the clinical evidence analyzed in a meta-analysis of the efficacy of allergen immunotherapy in mite-induced rhinitis and asthma. Safety and tolerability are very good, mild local reactions in the mouth being the most common side effect. This makes it feasible to carry out sublingual immunotherapy for the 3-5-year duration needed to achieve long-lasting tolerance to the specific allergen. The performance of Staloral 300 may provide optimal conditions for an effective and safe sublingual immunotherapy in patients with mite-induced respiratory allergy.

The current role of sublingual immunotherapy in the treatment of allergic rhinitis in adults and children.

Allergic rhinitis is a very common disease affecting about 20% of people. It may be treated by allergen avoidance when possible, by antiallergic drugs such as antihistamines and topical corticosteroids, and by allergen-specific immunotherapy. The latter is the only treatment able to act on the causes and not only on the symptoms of respiratory allergy and is able to maintain its efficacy even after stopping, provided an adequate duration of treatment of 3-5 years is ensured. Sublingual immunotherapy (SLIT) was introduced in the 1990s as a possible solution to the problem of adverse systemic reactions to subcutaneous immunotherapy and has been demonstrated by more than 50 trials and globally evaluated thus far by five meta-analyses as an effective and safe treatment for allergic rhinitis. Life-threatening reactions are extremely rare. However, it is important to note that clinical efficacy occurs only if SLIT meets its needs, ie, sufficiently high doses are regularly administered for at least 3 consecutive years. This is often overlooked in the current practice and may prevent the same success reported by trials from being achieved.

Idiopathic eosinophilic parotitis in an eight-year-old boy: a case report.

INTRODUCTION: A number of medical conditions, some of them recently reported, are associated with an increased production of eosinophils. We report the first case of eosinophilic parotitis in the literature. CASE PRESENTATION: The patient was an eight-year-old Caucasian boy who presented with a two-year history of recurring acute parotitis with no fever. He had had a total of five episodes with no response to antibiotics, but remission had been achieved with oral corticosteroid therapy. We performed allergy tests for inhalant and food allergens and for haptens, but the results were all negative. The results of echography ruled out sialodochitis. Instead, a swab from the parotid duct led to the detection of a high number of eosinophils. CONCLUSIONS: This report is first in the literature to describe a case of eosinophilic parotitis, and we suggest that a cytological assessment, which is quite simple yet rarely used by physicians, be performed when patients with parotitis of uncertain origin are under evaluation.

Polysensitization as a challenge for the allergist: the suggestions provided by the Polysensitization Impact on Allergen Immunotherapy studies.

INTRODUCTION: Polysensitization, that is, sensitization to more than one allergen family, is a common feature of patients with allergic rhinitis (AR) and significantly impairs their quality of life (QoL). Allergen-specific immunotherapy is the only causal treatment for AR. However, the polysensitization phenomenon may represent a crucial obstacle as far as it concerns the choice of the allergen extract to be used for immunotherapy. AREAS COVERED: A series of real-life based multi-center studies, named POLISMAIL (Polysensitization Impact on Allergen Immunotherapy), have been designed with the aim of evaluating the behavior of allergists in managing polysensitized AR patients. The effect of immunotherapy treatment in these patients was also evaluated. A single allergen extract was used in two-thirds of patients, whereas a mix of two allergens was chosen in the remaining. The severity grade of AR and the QoL were significantly improved by immunotherapy. Both outcomes confirmed that immunotherapy with one or two allergen extracts achieves a significant improvement in polysensitized patients. EXPERT OPINION: In conclusion, POLISMAIL studies demonstrate that polysensitization should not represent a counter-indication for prescribing immunotherapy. The choice of limiting sublingual immunotherapy to one to two allergen extracts, preferably separated and at high dosages, is sufficient and effective in improving symptoms and QoL.

Patient-related factors in rhinitis and asthma: the satisfaction with allergy treatment survey.

BACKGROUND: Patient satisfaction with the prescribed treatments represents a crucial issue that may have clinical relevance as it may significantly affect treatment compliance. We designed an observational study to evaluate the satisfaction level concerning different pharmacological treatments for allergic rhinitis (AR) and asthma in a real-life setting. METHODS: The study was conducted in 21 allergy centres homogeneously distributed in Italy. Three hundred and one patients (46.8% males; 53.2% females; mean [SD] age, 33.1 [13.8] years) with AR and/or asthma were consecutively evaluated. Diagnosis, classification, symptom severity, and satisfaction degree (assessed by a questionnaire) were the parameters considered. RESULTS: Only 33.5% of the AR patients were satisfied with the rhinitis treatments. Only 40.7% of the asthmatic patients were satisfied with the asthma treatments. Some factors associated with treatment dissatisfaction are as follows: female gender (odds ratio [OR] 2.36; p < 0.01), co-morbidity (OR 2.39; p < 0.05), rhinitis severity (OR 1.39; p < 0.05), asthma severity (OR 2.04; p < 0.05), and antihistamine use (OR 2.53); however, the use of bronchodilators had a favourable impact (OR 0.28; p < 0.05). The relatively low number of subjects prevented performing stratification of patients by treatment classes. CONCLUSION: The findings of this real-life study strengthen the concept that AR is particularly troublesome and that most allergic patients suffering from both rhinitis and asthma are dissatisfied with prescribed drugs.

Adherence issues related to sublingual immunotherapy as perceived by allergists.

OBJECTIVES: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. METHODS: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. RESULTS: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. CONCLUSION: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers.