[Value of allergen nasal provocation test in assessment of the efficacy of house dust mites specific immunotherapy].

Objective:To investigate the value of nasal provocation test（NPT） in evaluating the efficacy of allergen immunotherapy（AIT） in patients with dust mite induced allergic rhinitis（AR）. Methods:A total of 83 patients with dust mite induced AR with/without asthma were included. Symptom score（SS）, daily medication score（DMS）, combined symptom and medication score（CSMS）, rhinoconjunctivitis quality of life questionnaire（RQLQ）, NPT and skin prick test（SPT） were assessed before and after 1 year AIT. Results:There were statistical differences in SS（P<0.000 1）, DMS（P<0.000 1）, CSMS（P<0.000 1）, and RQLQ（P<0.000 1） after 1 year of AIT compared with pre-treatment. The effective rate of CSMS was 73.49%, and the effective rate of NPT was 42.17%. CSMS was consistent with NPT in efficacy assessment（Kappa=0.437, P<0.001）; while in 54 patients with pre-treatment NPT concentrations other than the original concentration, CMSM and NPT showed better consistence（Kappa=0.895, P<0.001）. Among the 48 patients with ineffective NPT assessment in the first year, 25 patients completed the second-year follow-up, and 12 patients（48.00%） showed effective in NPT. However, 10 out of 12 patients（83.33%） with NPT concentration other than original solution pre-treatment showed effective NPT at the second year. Conclusion:NPT can be used as one of the indicators for efficacy evaluation for dust mite induced AR patients, especially for patients with positive NPT induced at lower concentrations before treatment.

Symptom Assessment of Patients with Allergic Rhinitis Using an Allergen Exposure Chamber.

Allergen exposure chambers (AECs) are clinical facilities that allow the exposure of participants to allergenic and non-allergenic airborne particles. They provide stable particle concentrations under controlled environmental conditions. This is of great importance both for diagnostic purposes and for the monitoring of treatment effects. Here, a protocol and the technical prerequisites for performing a safe and effective allergen challenge in subjects sensitized to airborne allergens (i.e., house dust mite [HDM]) in the ALL-MED AEC are presented. With this method, triggering allergic symptoms corresponds to natural exposure. This can be used for an allergy diagnosis or as a plausible endpoint in clinical trials, particularly for allergen immunotherapy (AIT). A controlled environment (temperature, humidity, and carbon dioxide [CO2]) in the chamber must be maintained. Allergen particles must be dispersed evenly within the AEC at stable levels throughout the challenge. For this presentation, allergic rhinitis (AR) patients sensitive to HDM allergens were enrolled. AR symptoms were assessed by the following parameters: total nasal symptom score (TNSS), acoustic rhinometry (ARM), peak nasal inspiratory flow (PNIF), and nasal secretion weight. The safety of the procedure was assessed by the peak expiratory flow rate (PEFR) and the forced expiratory volume in the first second (FEV1). The allergic subjects developed symptoms within 120 min of the trial. On average, the most intense symptoms appeared after 60-90 min and, after reaching a plateau, remained stable until the end of the trial.

Indoor exposure assessment for levels of dust mite and total volatile organic compounds (TVOCs) in living houses.

The purpose of this study is to measure the levels of dust mites (Dermatophagoides farina group 1 [Der f1] and Dermatophagoides pteronyssinus group 1 [Der p1]) and total volatile organic compounds (TVOCs) in the resident environments with living conditions such as the number of ventilation; the number of window, floor, and temperature; and relative humidity (RH) from vulnerable class in South Korea. Information on residents is designed to be prepared by residents on their general characteristics (daily residence time, heating and cooking type, and cleaning on the day of sampling). Dust mites levels ranged from 24.0 to 1087.5 ng/g with a mean of 215.4 ng/g for Der f1 and from 0.6 to 489.9 ng/g with a mean of 489.9 ng/g for Der p1. Total TVOC levels ranged from 15.3 to 1642.1 µg/m3 with a mean of 219.7 µg/m3. The correlation analysis showed a positive association between Der f1 levels and xylene levels in fall (r = 0.49, r < 0.05) of this study.

Detection and assessment of dust mite allergens in an indoor environment in Anhui, China.

Dust in the home environment is thought to be a potential trigger for increasing allergic diseases, such as allergic rash, rhinitis, asthma, and other conditions, associated with dust mites. To verify the status of dust mite prevalence in indoor surroundings, we collected 189 dust samples from the air conditioner filters (n = 75) and floors (n = 114) of households, schools, and hotels in the Anhui area, China. All samples were measured for dust mite breeding rate and breeding density under light microscopy and analyzed for dust mite species Dermatophagoides farinae 1 (Der f 1) and Dermatophagoides pteronyssinus 1 (Der p 1) allergen using enzyme-linked immunosorbent assay (ELISA). The dust mite breeding rates were 34.67% (26/75) and 20.18% (23/114), respectively, in the dust samples from the floor and air conditioning filters. The breeding density was the highest in households (10/g), followed by schools (9/g) and hotels (4/g). ELISA indicated that the allergen threshold (2.0 µg/g dust) of Der f 1 was exceeded in only two samples and Der p 1 in one sample. Additionally, a questionnaire was used to investigate the health knowledge on allergic diseases involved in indoor facilities, finding that most allergy sufferers were aware that indoor dust might be responsible for their conditions. The findings suggest that regular maintenance of indoor hygiene and cleaning of air-conditioning filters should reduce the risks of exposure to indoor allergens.

House dust mite allergens and nitrated products: Identification and risk assessment in indoor dust.

Air pollutants can potentially lead to nitration of allergic proteins, thus promoting sensitization of these allergens. However, little is currently known about the nitration status of house dust mite (HDM) allergens. We identified the occurrence of nitrated products of two major HDM allergens Der f 1 and Der p 1 in dust samples collected from college dormitories in eastern China and assessed their associated health risk. The results showed that both non-nitrated and nitrated forms of the two allergens were detected in the dust in the range of non-detected (ND)-10.6, 1.44-15.4, ND-22.4, ND-7.28 µg/g for non-nitrated Der f 1, nitrated Der f 1, non-nitrated Der p 1 and nitrated Der p 1, respectively. The median rates of nitration were determined as 74.0% for Der f 1 and 20.4% for Der p 1 at consideration of one nitration site. Further analysis reveals that the levels of HDM allergens and their nitrated products were found to be generally higher during winter, in dormitories of lower altitude and with female occupants. Furthermore, the calculated risk indexes were at considerably high levels. Our findings suggest that nitrated HDM allergens have already accumulated in the environment at such significant levels and their associated health risk calls for our immediate attention.

Validated allergen exposure chamber is plausible tool for the assessment of house dust mite-triggered allergic rhinitis.

BACKGROUND: Allergen exposure chamber (AEC) is a clinical facility that allows exposure to allergenic airborne particles in controlled environment. Although AECs offer stable levels of airborne allergens, the validation of symptoms and other endpoints induced by allergen challenge is key for their recommendation as a plausible tool for the assessment of patients, especially in clinical research. This study aimed to demonstrate the reproducibility of defined clinical endpoints after AEC house dust mite (HDM) challenge under optimal conditions in patients with allergic rhinitis (AR). METHOD: HDM was distributed at different concentrations. The assessment was subjective by the patients: total nasal symptom score (TNSS), visual analog scale (VAS), and objective by the investigator: acoustic rhinometry, peak nasal inspiratory flow (PNIF), and nasal secretion weight. Safety was assessed clinically and by peak expiratory flow rate (PEFR) and forced expiratory volume in the first second (FEV1 ). RESULTS: Constant environment: temperature, humidity, and carbon dioxide (CO2 ) concentration were maintained during all challenges. The concentration of HDM on average remained stable within the targeted values: 1000, 3000, 5000, 7000 particles (p)/m3 . Most symptoms were observed at concentrations 3000 p/m3 or higher. The symptoms severity and other endpoints results were reproducible. 5000 p/m3 , and challenge duration of 120 min were found optimal. The procedure was safe with no lung function abnormalities due to challenge. CONCLUSION: HDM challenge in ALL-MED AEC offers a safe and reliable method for inducing symptoms in AR patients for the use in controlled clinical studies including allergen immunotherapy.

Simultaneous assessment of organophosphate flame retardants, plasticizers, trace metals, and house dust mite allergens in settled house dust.

Settled house dust (SHD) is a reservoir for various contaminants, including endocrine-disrupting chemicals (EDCs), trace metals, and house dust mite allergens. This study aimed to characterize various chemical and biological contaminants in SHD and identify determinants governing the indoor contaminants. In total, 106 SHD samples were collected from 106 houses in Seoul and Gyeonggi Province, Korea, in 2021. Bedding dust samples were collected from 30 of these 106 houses. All participants completed a questionnaire comprised of housing and lifestyle-related factors. The samples were analyzed for 18 organophosphate flame retardants (OPFRs), 16 phthalates, five alternative plasticizers (APs), seven trace metals, and two house dust mite allergens (Dermatophagoides farinae type 1 [Der f1] and Dermatophagoides pteronyssinus type 1 [Der p1]). A multiple regression analysis was conducted to identify the determinants governing the concentrations and profiles of various contaminants. OPFRs, phthalates, APs, and trace metals were detected in all SHD samples, indicating ubiquitous contamination in indoor environments. Among the three EDC groups, APs were detected at the highest concentrations (geometric mean [GM] (geometric standard deviation, [GSD]): 1452 (1.6) µg/g in total), followed by phthalates (GM (GSD): 676 (1.4) µg/g in total) and OPFRs (GM (GSD): 10 (1.4) µg/g in total). Der f1 was detected in all bedding dust samples with significantly higher levels than Der p1 (GM (GSD): 0.1 (1.8) µg/g vs. 1.4 × 10-3 (2.3) µg/g). The concentrations of OPFRs, plasticizers, and trace metals in SHD were significantly associated with the type and number of electronic appliances and combustion activities. Der f1 was significantly associated with the number of occupants and water penetration. Ventilation, vacuum cleaning, and wet cleaning or dry mopping significantly reduced the levels of most contaminants in SHD. As residents are persistently exposed to a wide array of pollutants, comprehensive and adequate measures are required to prevent potential exposures.

Cost-effectiveness analysis of house dust mite allergen immunotherapy in children with allergic asthma.

BACKGROUND: Cost-effectiveness studies evaluating allergen immunotherapy (AIT) in children are limited but needed to drive clinical and policy-making decisions such as reimbursement of new interventions. In this study, we compared the cost effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) tablets to the standard of care (SOC) treatment in children with house dust mite-driven (HDM) allergic asthma. METHODS: We developed a hypothetical Markov model based on the Global Initiative for Asthma (GINA) severity steps to compare the three strategies over a 10-year horizon divided by cycles of 6 months. SOC was used as a reference to calculate the incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were used to assess models' uncertainty. Other scenarios were evaluated to strengthen the presentation of results. RESULTS: The ICER for SCIT and SLIT tablets was 1281€ and 7717€, respectively. The cost-effectiveness threshold for Portugal was 18,482.80€; both treatment approaches were below this limit. The major contributors to these results were the AIT effects on reducing moderate and severe exacerbations and asthma controller medication. In the sensitivity analysis, SCIT revealed a higher probability of cost-effectiveness than SLIT. When including allergic rhinitis as comorbidity, ICER values reduced markedly, especially for SCIT intervention. CONCLUSIONS: AIT was cost effective in children with HDM-driven allergic asthma, especially when given by the subcutaneous route. The high probability of cost effectiveness, especially for SCIT, may drive future policy decisions and AIT-prescribing habits. AIT adherence greatly influenced the results highlighting the value of implementing strategies to promote adherence rates.

Evaluation and predictive value of IgE responses toward a comprehensive panel of house dust mite allergens using a new multiplex assay: a real-life experience on an Italian population.

Summary: Background. House dust mites (HDM) are among the most important allergen sources worldwide, representing a major cause of perennial allergic rhinitis and asthma. Aim. To evaluate the prevalence of IgE responses towards a comprehensive panel of HDM allergens and to evaluate the implications of molecular sensitization profiles on respiratory symptoms. Methods. 155 consecutive HDM-allergic patients (mean age: 27.5 years; range: 1-62; female: 63), 86 affected by rhinitis and 68 by asthma, were enrolled. Specific IgE reactivity to Der f 1, Der p 1, Der f 2, Der p 2, Der p 5, Der p 7, Der p 10, Der p 11, Der p 20, Der p 21 and Der p 23 was tested in patients' sera using the last version of the multiparametric assay Allergy Explorer (ALEX). Results. In all, major and minor allergens were positive, respectively, in 96.8% and 50.9% of the patients. Prevalence and IgE levels of Der f 1, Der f 2, Der p 1 and Der p 20 were significantly higher in asthmatic patients (p less than 0.05), whereas subjects negative for minor allergens resulted more frequently suffering from rhinitis (p = 0.0001). Asthmatic patients had IgE reactivity to a larger number of HDM allergens (mean 5.4; SD ± 2.3) than patients with only rhinitis (mean 4.2; SD ± 2.5) (p = 0.003), whereas no differences in the number of HDM positive molecules and in the specific IgE levels were found among different ages. Conclusions. This study confirms that the assessment of IgE to a comprehensive panel of HDM allergens defines different serological reactivity profiles that seem associated with different clinical presentations.

Satisfaction of allergic patients treated with house dust mite sublingual immunotherapy.

Sublingual immunotherapy (SLIT) has been used for more than three decades as a therapeutic strategy for the treatment of allergic diseases. Studies have demonstrated its efficacy and safety, and numerous clinical trials have evaluated these parameters. In the present study, through patient perception, we investigated the patient satisfaction with the use of house dust mite SLIT treatment. "Satisfaction Scale for Patients Receiving Allergen Immunotherapy" (ESPIA) questionnaire, a standardized and validated instrument for clinical studies evaluating allergen immunotherapy, was applied to allergic patients (N = 136). Children and adults of both sexes who received SLIT for Dermatophagoides pteronyssinus and/or Blomia tropicalis, according to the results of an immediate reading puncture test, were included. Data analysis showed that the perception of treatment effectiveness was 92%, performance improvement in the daily activities was 91%, a satisfactory cost-benefit balance was 84%, and the perception of general satisfaction was 97%. The results showed a high perception of satisfaction in allergic patients undergoing house dust mite SLIT.

Dermatophagoides spp. hypoallergens design: what has been achieved so far?

Introduction: Allergic illnesses are one of the most prevalent immunological disorders worldwide and house dust mites are important triggers of these diseases. Allergen-specific immunotherapy (AIT) is an alternative treatment to pharmacotherapy and among its technologies, recombinant hypoallergenic derivatives have shown promising features, turn them into safer and more efficient allergy vaccines.Areas covered: Patents and scientific publications referring to advances in the design of Dermatophagoides spp. hypoallergenic molecules. Data were obtained from the Espacenet® and PubMed websites, using different key terms, advanced tools and Boolean operators for searches. The retrieved data were then descriptively analyzed, taking into consideration clinical targets, geographical, temporal, collaborative, and different classification aspects of the productions.Expert opinion: Joint advances of molecular biology, genetic engineering, and bioinformatics technologies led to progresses in the design of Dermatophagoides spp. hypoallergenic derivatives. Collaborative networks seem to be an interesting way not only to improve technologies in AIT but also to boost the number of patents, publications, and grants for researchers. The observed trend for the use of hypoallergenic hybrid molecules was a fundamental AIT advance and this type of molecule appears to be a more attractive product for companies and more convenient, efficient, and safer allergy immunotherapy for patients.

Socio-environmental profile of child and adolescents sensitized by house dust mite in northeast of Brazil.

INTRODUCTION: The association regarding the atopic sensitization to mite aeroallergens and the socio-environmental features is still inconsistent. OBJECTIVES: We analyzed the role played by socioeconomic and environmental factors in the prevalence of sensitization to house dust mite (HDM) allergens, and associated with the risk of developing asthma symptoms. PATIENTS AND METHODS: This is a case-control study conducted with 108 patients, aged 1-17. We inquired about family habits, socioeconomic and environmental features. We applied the International Study of Asthma and Allergies in Childhood questionnaire. RESULTS: We observed patients sensitized to all HDM tested, Derp (42%), Derf (37%) and Blot (33%). Middle family income (OR: 2.74; CI95%: 1.127-6.684), exposure to dog (OR: 3.758, CI95%: 1.127-6.684) and artificial climatization (OR: 4.319, CI95%: 1.398-13.348) were associated with sensitization to Derp. We also observed protective factors, such as sharing of dormitories, washing cycle for bedspreads and the presence of basic sanitation. An increased risk of sensitization to Derf was associated with Blot sensitization (OR: 3.172, CI95%: 1.083-9.292) and presence of mold on the walls (OR: 3.095, CI95%: 1.063-9.008). A protective factor was dormitory sharing. For sensitization to Blot, we observed an increase in the risk associated with Derp sensitization (OR: 3.462, CI95%: 1.191-10.061) and exposure to dog (OR: 3.255, CI95%: 0.987-10.736). In addition, sensitization to Blot increases the risk of developing asthma symptoms (OR: 2.732, CI95%: 0.981-7.606). CONCLUSION: Our data show distinct sociodemographic and environmental relations that lead to HDM sensitization and increased probability of development of allergic diseases.

Cost-effectiveness of the SQ HDM SLIT-tablet for the treatment of allergic asthma in three Eastern European Countries.

Summary: Background.The SQ® house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (ACARIZAX®, ALK-Abelló A/S, Hørsholm, Denmark) is an allergy immunotherapy tablet for people with allergic respiratory disease. This analysis aims to assess the cost-effectiveness of the SQ HDM SLIT-tablet from the perspective of three Eastern European countries: Czech Republic, Poland and Slovakia. Methods.A cost-utility model per country was developed, which compared the SQ HDM SLIT-tablet as add-on to pharmacotherapy with pharmacotherapy alone in patients with HDM allergic asthma (AA) over a five year time horizon. The effectiveness of the two interventions was based on the results from a large-scale randomised controlled trial. In the models, annual costs and quality-adjusted life year (QALY) scores from the trial were extrapolated over a five year period, and the incremental cost-effectiveness ratios (ICERs) were estimated. One-way deterministic sensitivity and scenario analyses were undertaken. Results.The SQ HDM SLIT-tablet is cost-effective in all three markets over the five year time horizon (ICERs of less than € 10,000 per additional QALY). Treatment with the SQ HDM SLIT-tablet improves patient outcomes, with QALY gains of 0.35, versus pharmacotherapy only. In all three countries, the SQ HDM SLIT-tablet also incurs increased costs compared to pharma-cotherapy treatment only. The sensitivity analysis identified utility values from the clinical trial as the main driver of the model results. Conclusion.The SQ HDM SLIT-tablet is a cost-effective treatment option for people with HDM AA in three different health care settings in Eastern Europe.

Clinical Characteristics and Allergen Sensitization Patterns of Patients with Local Allergic Rhinitis in Southern China.

BACKGROUND: Local allergic rhinitis (LAR) is characterized by the production of specific IgE (sIgE) in the nasal mucosa without evidence of systemic atopy. The characteristics of LAR in Caucasians have been well documented. LAR is understudied in China, with prevalence, patient demographics, symptomatology, and the allergen sensitization profile being poorly understood. The purpose of this study is to investigate the demographics, characteristics, and allergen sensitization profile of patients with LAR in Southern China. METHODS: A total of 194 patients with rhinitis and 13 healthy subjects were enrolled in the current study. The patients' demographic data, clinical history, and symptoms were recorded. Local and systemic sIgE to a wide panel of specific allergens were measured in the nasal secretion and serum samples. RESULTS: Among the rhinitis patients, 115 were classified as allergic rhinitis (AR; 59.3%), 15 as LAR (7.7%), and 64 as non-AR (33.0%). The demographic characteristics, duration, frequency, and severity of symptoms were similar, although LAR exhibited higher symptom scores for nasal itch. Monosensitization was the predominant pattern of sensitization in both AR (109 out of 115, 95%) and LAR (14 out of 15, 93%). House dust mite was the dominant allergen in AR patients (109 out of 115, 95%), while pollen was the dominant allergen in LAR patients (11 out of 15, 73%). CONCLUSION: The prevalence of LAR patients in Southern China was 7.7%. Pollen was the most common sensitizing allergen for the local LAR patients, which differs from Caucasian studies, in which house dust mite was the dominant sensitizing allergen. Monosensitization was the predominant pattern in both AR and LAR.

A Cost-Minimisation Analysis Comparing Sublingual Immunotherapy to Subcutaneous Immunotherapy for the Treatment of House Dust Mite Allergy in a Swedish Setting.

BACKGROUND AND OBJECTIVES: In Sweden, approximately 6% of children and 10% of adults suffer from house dust mite (HDM) allergy with symptoms of allergic rhinitis and allergic asthma. Treatment is aimed at reducing HDM exposure and to control the symptoms of allergic rhinitis and allergic asthma by symptom-relieving pharmacotherapy. This pharmacotherapy is often effective, but some patients remain inadequately controlled. For these patients, allergy immunotherapy (AIT, subcutaneous or sublingual) with repeated administration of HDM allergen should be considered. The objective of this study was to compare the costs for sublingual AIT (SLIT; SQ® SLIT-tablet) to the costs for subcutaneous AIT (SCIT; SQ® SCIT) for the treatment of HDM allergy in a cost-minimisation analysis (CMA). METHODS: The CMA included resources (and costs) for treatment, healthcare visits, travelling and lost productivity. Resource use based on Swedish clinical treatment practice and costs were obtained from medical price lists. Analyses were conducted from the societal, as well as healthcare perspective, by use of a time horizon of 3 years. RESULTS: The results show that SQ® SLIT-tablet is a cost-saving treatment as compared to SQ® SCIT for the treatment of HDM allergy (€6800 over 3 years). The results are mainly driven by the cost of healthcare visits and the frequency of SCIT administrations. CONCLUSION: In conclusion, cost-savings of €6800 over 3 years are expected from treating HDM allergy with SQ® SLIT-tablet as compared to SQ® SCIT, including costs for treatment, healthcare visits, travelling and lost productivity. The reduced number of healthcare visits compensates for higher medication costs.

Evolution and predictive value of IgE responses toward a comprehensive panel of house dust mite allergens during the first 2 decades of life.

BACKGROUND: The evolution of the IgE response to the numerous allergen molecules of Dermatophagoides pteronyssinus is still unknown. OBJECTIVES: We sought to characterize the evolutionary patterns of the IgE response to 12 molecules of D pteronyssinus from birth to adulthood and to investigate their determinants and clinical relevance. METHODS: We investigated the clinical data and sera of 722 participants in the German Multicenter Allergy Study, a birth cohort started in 1990. Diagnoses of current allergic rhinitis (AR) related to mite allergy and asthma were based on yearly interviews at the ages of 1 to 13 years and 20 years. IgE to the extract and 12 molecules of D pteronyssinus were tested by means of ImmunoCAP and microarray technology, respectively, in sera collected at ages 1, 2, 3, 5, 6, 7, 10, 13, and 20 years. Exposure to mites at age 6 and 18 months was assessed by measuring Der p 1 weight/weight concentration in house dust. RESULTS: One hundred ninety-one (26.5%) of 722 participants ever had IgE to D pteronyssinus extract (≥0.35 kUA/L). At age 20 years, their IgE recognized most frequently Der p 2, Der p 1, and Der p 23 (group A molecules; prevalence, >40%), followed by Der p 5, Der p 7, Der p 4, and Der p 21 (group B molecules; prevalence, 15% to 30%) and Der p 11, Der p 18, clone 16, Der p 14, and Der p 15 (group C molecules; prevalence, <10%). IgE sensitization started almost invariably with group A molecules and expanded sequentially first to group B and finally to group C molecules. Early IgE sensitization onset, parental hay fever, and higher exposure to mites were associated with a broader polymolecular IgE sensitization pattern. Participants reaching the broadest IgE sensitization stage (ie, ABC) had significantly higher risk of mite-related AR and asthma than unsensitized participants. IgE to Der p 1 or Der p 23 at age 5 years or less predicted asthma at school age. CONCLUSIONS: Parental hay fever and early exposure to D pteronyssinus allergens promote IgE polysensitization to several D pteronyssinus molecules, which in turn predicts current mite-related AR and current/future asthma. These results might inspire predictive algorithms and prevention strategies against the progression of IgE sensitization to mites toward AR and asthma.

Real-Life Study for the Diagnosis of House Dust Mite Allergy - The Value of Recombinant Allergen-Based IgE Serology.

BACKGROUND: Dermatophagoides pteronyssinus is one of the most important perennial allergen sources worldwide. Molecular diagnostics using the commercially available major allergens (Der p 1 and Der p 2) in combination with Der p 10 do not detect house dust mite (HDM) sensitization in a number of cases when used alone. The objective was to evaluate the IgE reactivity profiles of these patients using an experimental immunoassay biochip. METHODS: Sera of HDM-allergic patients (positive skin prick test, CAP class ≥1 for allergen extract, and positive intranasal provocation) were tested for IgE antibodies against Der p 1, Der p 2, and Der p 10 by ImmunoCAP fluorescence enzyme immunoassay. Negatively tested sera were examined by an experimental chip containing 13 microarrayed HDM allergens. RESULTS: Of 97 patients tested, 16 showed negative results to Der p 1, Der p 2, and Der p 10. MeDALL chip evaluation revealed 5 patients monosensitized to Der p 23, and 11 patients were negative for all HDM MeDALL chip components. Seven sera were available for further testing, and 3 of them showed IgE reactivity to dot-blotted nDer p 1, and 2 reacted with high-molecular weight components (>100 kDa) in nitrocellulose-blotted HDM extract when tested with 125I-labeled anti-IgE in a RAST-based assay. The HDM extract-specific IgE levels of the 11 patients were <3.9 kU/l. CONCLUSIONS: Recombinant allergen-based IgE serology is of great value when conventional IgE diagnostics fails. Der p 23 is an important HDM allergen, especially when major allergens are negative. Therefore, it would be desirable to have Der p 23 commercially available. Further research concerning the prevalence and clinical significance of different HDM allergens is needed.

Cost-minimization analysis of sublingual immunotherapy versus subcutaneous immunotherapy for house dust mite respiratory allergic disease in Denmark.

Objectives Currently, patients with persistent moderate-to-severe house dust mite (HDM) allergic rhinitis despite use of symptom-relieving medication can be offered subcutaneously administered allergy immunotherapy (SQ SCIT; Alutard SQ) as standard care of treatment in Denmark. Recently, a HDM sublingually administered allergy immunotherapy tablet (SQ SLIT-tablet; ACARIZAX) has been developed for at-home treatment. The purpose of this analysis is to compare the costs related to treatment and administration of SQ SLIT-tablet and SQ SCIT. Methods Assuming equal efficacy between ther SQ SLIT-tablet and SQ SCIT, the cost-minimization analysis was the most appropriate for the comparison. According to guidelines and Summary of Product Characteristics, the treatment duration of SQ SLIT-tablet is 3 years and 3-5 years for SQ SCIT. The courses of treatment vary among patients and, therefore, the costs of treatment have been calculated for an average patient with HDM respiratory allergic disease (RAD) receiving either SQ SLIT-tablet or SQ SCIT. All costs associated with allergy immunotherapy were collected, i.e., cost of medication, administration and treatment setting, and discounted according to Danish guidelines. Comprehensive univariate sensitivity analyses were carried out. Results The treatment costs for an average patient with HDM RAD are €3094 for SQ SLIT-tablet and €3799 for SQ SCIT; however, when adding indirect costs to the calculations the total costs of the treatments are €3697 and €6717 for SQ SLIT-tablet and SQ SCIT, respectively. Therefore, if 2500 patients with HDM RAD were treated with SQ SLIT-tablet instead of SQ SCIT, it would elicit a saving to the healthcare system of ∼€1.8 million. The conclusion was robust to any changes in the sensitivity analysis. Conclusion With regards to the cost of treating Danish patients with HDM RAD, it is clearly cost-saving to treat patients with SQ SLIT-tablet compared to SQ SCIT.