Impact of sublingual immunotherapy on specific antibody levels in asthmatic children allergic to house dust mites

OBJECTIVE: To evaluate the clinical outcome and changes in allergen-specific antibodies during sublingual immunotherapy (SLIT) in house dust mite (HDM)-allergic asthma patients and to compare levels of allergen-specific antibodies in HDM-allergic patients before and after treatment with that of healthy controls. METHOD: Thirty-one asthma patients allergic to HDM were studied. Patients in groups I (n=17) and II (n=14) received SLIT with a standardized Dermatophagoides pteronyssinus plus Dermatophagoides farinae 50/50 extract for 6 and 12 months, respectively. A group of healthy children (n=8) were enrolled as controls. Patients in both groups were evaluated at the start and at the end of treatment according to daily symptom and medication scores, lung function and skin prick tests, PC20, blood eosinophil count, and Der-p-1-specific IgE, IgA, IgG1 and IgG4 levels. RESULTS: Drug consumption decreased significantly in both groups. Furthermore, PC20 and forced expiratory flow between 25 and 75% of vital capacity of patients in group II improved significantly. Although specific IgA, IgG1 and IgG4 levels did not change throughout the treatment period, total eosinophil count and specific IgE decreased significantly in both groups. According to baseline measurements, specific IgA levels of patients in groups I and II were significantly lower than that of controls. This difference disappeared at the end of the treatment period in both groups. CONCLUSION: SLIT seems to be effective in ameliorating clinical symptoms, drug consumption and bronchial hyperreactivity, and results in downregulation of Der-p-1-specific IgE production. Furthermore, at the end of SLIT, specific IgA levels, which were decreased compared to healthy controls initially, did no longer differ between patients and controls.     

Sublingual‐swallow immunotherapy (SLIT) in patients with asthma due to house‐dust mites: a double‐blind, placebo‐controlled study

A double-blind, placebo-controlled study was carried out in 85 patients with a well-documented history of perennial asthma caused by house-dust mites. Patients received either placebo or sublingual immunotherapy (SLIT) with a standardized Dermatophagoides pteronyssinus (DP)-D. farinae (DF) 50/50 extract. After a run-in period, patients received increasing doses up to 300 IR every day for 4 weeks and then three times a week for the following 24 months. The cumulative dose was about 104000 IR, equivalent to 4.2 mg Der p 1 and 7.3 mg Der f 1. Symptom and medication scores and respiratory function were assessed throughout the trial. Serum specific IgE and IgG4 were determined before SLIT (t0) and after 6 (t1), 11 (t2), 17 (t3), and 25 months (t4) of SLIT. Mite exposure was evaluated at t0, t2, and t4 by semiquantitative guanine determinations. Patients aged 15 years and older were asked to assess their quality of life (QoL) by completing the SF20 (Short Form Health Status Survey) plus two items at t0, t2, and t4. Use of inhaled corticosteroids and beta2-agonists was significantly decreased after 25 months of treatment in both groups (P<0.03). SLIT patients showed significant improvements in respiratory function at t4 (% predicted FEV1 (P = 0.01), VC (P = 0.002), morning (P = 0.01) and evening (P = 0.03) PEFR), and reduction in daytime asthma score (P = 0.02). In the SLIT group, the post-treatment PD20 was 1.75 times higher than the baseline value. There was no change in PD20 in the placebo group. Compared to the placebo group, the SLIT group showed a significant increase in specific IgE DP(P = 0.05), IgE DF(P = 0.02), IgG4 DP(P = 0.001), and IgG4 DF (P = 0.001) levels after SLIT. QoL scores were similar in both groups at t0 and t2. At t4, all scores were better in the SLIT group than in the placebo group, with the differences being most marked for the general perception of health (P = 0.01) and physical pain (P = 0.02). Adverse events were similar in the two groups. This study shows that SLIT in house-dust-mite-related asthma has a good safety profile and improves respiratory function, bronchial hyperreactivity, and QoL.     

Sublingual immunotherapy with Dermatophagoides monomeric allergoid down-regulates allergen-specific immunoglobulin E and increases both interferon-γ- and interleukin-10-production

BACKGROUND: The clinical efficacy and safety of sublingual immunotherapy (SLIT) for aeroallergens has been demonstrated in several trials, whereas the immunological changes induced by this treatment, which may account for the clinical improvement, are still unclear. OBJECTIVE: To investigate the effects of a successful SLIT on the in vitro allergen-driven T cell response and cytokine secretion as well as on the serum levels of chemokines and of IgE, IgG1 and IgG4 antibodies (Abs). MATERIALS AND METHODS: Twenty-five Dermatophagoides pteronyssinus (Dp)-sensitive patients with perennial rhinitic and/or rhinitic and asthmatic symptoms were randomized into two groups (13 untreated (UT) and 12 SLIT-treated) for a 1 year and half study. The proliferative response of peripheral blood mononuclear cell (PBMC) to purified Der p1 allergen, their cytokines (IFN-gamma, IL-4, IL-10 and TGF-beta) production and serum levels of chemokines associated with T helper type 1 (Th1) (CXCL10) or T helper type 2 (Th2) (CCL22) responses and of Dp-specific IgE, IgG1 and IgG4 Abs were evaluated before and after 6 months of treatment. RESULTS: SLIT induced a significant reduction of symptom medication scores after 6, 12 and 18 months of treatment in comparison with UT patients. SLIT-treated patients showed a significant decrease in serum levels of DP-specific IgE Abs, whereas total IgE, and specific IgG1 and IgG4 Abs remained unchanged. The proliferative response of allergen-specific T cells to Der p1 in vitro after 6 months of treatment was reduced, while no effect was observed on T cell proliferation to recall antigen (streptokinase). Moreover, Der p1-driven IFN-gamma and IL-10 were significantly increased in culture supernatants of PBMC from 6 month-treated patients in comparison with those detected at the beginning of therapy. CONCLUSIONS: These data suggest that the allergen-driven enhancement of IL-10- and IFN-gamma-producing T cells precedes and associates with SLIT-induced down-regulation of specific IgE, thus providing a rationale to explain the clinical benefit of SLIT in allergic patients.     

Correlation of nasal inflammation and nasal airflow with forced expiratory volume in 1 second in patients with perennial allergic rhinitis and asthma.

BACKGROUND: Allergic rhinitis and asthma are frequently associated and are characterized by TH2-dependent inflammation. Nasal and bronchial obstruction largely depend on allergic inflammation. OBJECTIVE: To evaluate the relationships among nasal eosinophil counts, interleukin 4 (IL-4) and interferon-gamma (IFN-gamma) levels, nasal airflow, and forced expiratory volume in 1 second (FEV1) in patients with perennial allergic rhinitis and asthma. METHODS: Eight men and 7 women (mean +/- SD age, 24.8 +/- 4.7 years) with perennial allergic rhinitis and asthma were evaluated. All 15 patients had a moderate-to-severe grade of nasal obstruction. Total symptom score, rhinomanometry, nasal lavage, nasal scraping, and spirometry were evaluated in all patients. Eosinophils were counted using conventional staining; IL-4 and IFN-gamma levels were measured by immunoassay in fluids recovered from nasal lavage. RESULTS: Significant positive relationships were demonstrated between eosinophil infiltration and IL-4 levels, nasal airflow and IFN-gamma levels, FEV1 and IFN-gamma levels, and nasal airflow and FEV1 (P < .001 for all). Significant negative relationships were demonstrated between eosinophil infiltration and IFN-gamma levels, IL-4 and IFN-gamma levels, eosinophil infiltration and nasal airflow, IL-4 values and nasal airflow, nasal eosinophil counts and FEV1, and IL-4 values and FEV1 (P < .001 for all). CONCLUSIONS: There is a close association between TH2 cytokines and eosinophil infiltration in the nose. There is also clear evidence concerning the relationships among eosinophil infiltration, IL-4 and IFN-gamma levels, and nasal airflow. Nasal eosinophil, IL-4, and IFN-gamma levels correlate with FEV1. Finally, nasal airflow is related to FEV1. These findings constitute the first evidence of a relationship between TH2-related nasal inflammation and nasal and bronchial airflow in patients with perennial allergic rhinitis and asthma.     

Peripheral Blood Neutrophil Activity During Dermatophagoides pteronyssinus-Induced Late-Phase Airway Inflammation in Patients with Allergic Rhinitis and Asthma

Recent investigations suggest that neutrophils may play an important role in the late-phase allergen-induced inflammation in allergic airway diseases. The aim of this study was to evaluate neutrophil chemotaxis, phagocytic activity, and reactive oxygen species (ROS) production in patients with allergic rhinitis and asthma challenged with inhaled Dermatophagoides pteronyssinus. Eighteen patients with allergic rhinitis and 14 with allergic asthma, all sensitized to D. pteronyssinus, as well as 15 healthy individuals underwent bronchial challenge with D. pteronyssinus. Peripheral blood collection and neutrophil isolation were performed 24 h before as well as 7 and 24 h after bronchial challenge. Neutrophils chemotaxis, phagocytic activity, and ROS production were analyzed by flow cytometer. Neutrophil chemotaxis and ROS production were increased, while phagocytic activity was decreased 24 h before challenge in patient groups compared with healthy individuals. After challenge, neutrophil chemotaxis and phagocytic activity increased after 7 and 24 h, when ROS production, only after 24 h. Bronchial allergen challenge had no influence for neutrophils activity in healthy subjects. Activated chemotaxis, phagocytic activity, and ROS production of peripheral blood neutrophils after challenge with D. pteronyssinus reflect an enhanced systemic inflammation in allergic rhinitis and asthma patients with induced late-phase airway inflammation.     

Cord blood mononuclear cell cytokine responses in relation to maternal house dust mite allergen exposure

BACKGROUND: Cord blood mononuclear cells have demonstrated specific immune responses to environmental allergens. OBJECTIVE: To establish whether the nature of this response is related to the level of maternal antenatal exposure to house dust mite (HDM) allergen and, hence, whether antenatal allergen avoidance may have a role in the prevention of allergic sensitization in children. METHODS: Children with a family history of asthma were recruited antenatally as subjects in a randomised controlled trial: the Childhood Asthma Prevention Study. HDM allergen (Der p 1) concentrations were measured in dust collected from the maternal bed at 36 weeks gestation. Cord blood mononuclear cells were stimulated in culture, separately, with phytohaemaglutinin (PHA) and HDM extract. Cytokine IL-4, IL-5, IL-10 and IFN-gamma concentrations in supernatant were measured by ELISA. mRNA signals for these cytokines were measured using RT-PCR. RESULTS: The median concentration of HDM allergen was 18.4 microg/g (interquartile range 7.3-35.3 microg/g). Median concentrations of IL-4, IL-5, IL-10 and IFN-gamma, after PHA stimulation were 4, 19, 401 and 1781 pg/mL, respectively. After HDM allergen stimulation the median concentrations were 0, 0, 20 and 14 pg/mL, respectively. The distribution of mRNA cytokine signals was similar. Neither cytokine protein concentrations nor cytokine mRNA signal levels were correlated with the concentration of HDM allergen in the mothers' beds at 36 weeks gestation. CONCLUSION: These findings do not support the view that the prevention of allergic disease in children requires the institution of HDM avoidance interventions during pregnancy.     

Induction of interleukin 10 by sublingual immunotherapy for house dust mites: a preliminary report.

BACKGROUND: Subcutaneous specific immunotherapy has been demonstrated to be capable of inducing T-cell regulatory response. Interleukin 10 (IL-10) plays a crucial role in inducing allergen-specific tolerance; however, no previous studies have examined IL-10 production after sublingual immunotherapy (SLIT). OBJECTIVE: To evaluate T-cell proliferation and IL-10 production in patients successfully treated with SLIT for house dust mites (HDMs). METHODS: Peripheral blood mononuclear cells were isolated from patients after at least 3 years of successful HDM SLIT and from matched untreated allergic patients and healthy control subjects. After 3 and 6 days of in vitro stimulation with phytohemagglutinin (PHA), Candida albicans, and Dermatophagoides farinae, proliferation and production of IL-10 were measured. RESULTS: Patients treated with SLIT showed a significant reduction of proliferation induced by C albicans compared with untreated atopic patients (P < .001), but a significant reduction was also demonstrated in healthy controls compared with untreated atopic patients (P < .001). Patients treated with SLIT also showed a significant increase of IL-10 production after Candida and PHA stimuli compared with patients with untreated rhinitis (P < .001 for both). Patients with untreated rhinitis did not produce IL-10. CONCLUSION: This preliminary study confirms reduced T-cell proliferation and preliminarily provides the first evidence, to our knowledge, of peripheral IL-10 production in allergic patients successfully treated with HDM SLIT.     

Pediatric sublingual immunotherapy efficacy: evidence analysis, 2009-2012

ObjectiveTo perform a structured analysis of the latest scientific evidence obtained for the clinical efficacy of sublingual immunotherapy (SLIT) in children.Data SourcesPubMed, Embase, reference lists from reviews, and personal databases were reviewed for original articles on clinical trials with SLIT in patients younger than 18 years published from January 1, 2009, through December 31, 2012, using broad search and medical subject heading terms.Study SelectionsClinical trials, irrespective of their design, of SLIT in the treatment of respiratory and food allergy in patients 18 years or younger were selected. Clinical outcomes (symptom scores, medication use, provocation tests, pulmonary function tests, skin prick tests, and adverse events) and immunologic changes were tabulated. Quality of each trial and total quality of compounded evidence was analyzed with the Grading of Recommendations Assessment, Development and Evaluation system.ResultsOf 56 articles, 29 met the inclusion criteria. New evidence is robust for the precoseasonal tablet and drop grass pollen SLIT efficacy in allergic rhinitis and scarce for seasonal asthma. Some evidence for Alternaria SLIT efficacy is appearing. For house dust mite (HDM) SLIT in asthma, there is high-quality evidence for medication reduction while maintaining symptom control; evidence for HDM SLIT efficacy in allergic rhinitis is of moderate-low quality. There is moderate evidence for efficacy of dual grass pollen–HDM SLIT after 12 months of treatment and 1 year after discontinuation. Specific provocation test results (nasal, skin) improve with grass pollen and HDM SLIT but nonspecific bronchial provocation testing does not. Food oral immunotherapy is more promising than food SLIT. Possible new surrogate markers have been reported. No anaphylaxis was found among 2469 treated children.ConclusionEvidence for efficacy of SLIT in children with respiratory or food allergy is growing.     

In vitro responsiveness to IL-18 in combination with IL-12 or IL-2 by PBMC from patients with bronchial asthma and atopic dermatitis

Interleukin (IL)-18 is a proinflammatory cytokine and is now recognized as an important regulator of both helper T cells (Th) 1 and 2 cytokine production. An increased IL-18 secretion has been reported in patients with allergic disorders. It is predominantly produced by activated macrophages, and synergizes with IL-12 and IL-2 to induce IFN-gamma synthesis, thereby promoting Th1 cytokine response. Paradoxically, IL-18, by itself, strongly induces immunoglobulin (Ig) E and allergic inflammation, indicating a role for IL-18 in promoting Th2 response. We investigated the inducing effect in vitro of combining IL-18 and Il-12 or Il-2 on Th1- and Th2-type cytokines production by peripheral blood mononuclear cells (PBMC) from patients with allergic diseases. PBMC derived from 44 allergic patients [23 bronchial asthma (BA) and 21 atopic dermatitis (AD)] and 20 healthy controls were cultured with IL-18 in the presence of phytohemagglutinin (PHA) and IL-12 or IL-2. The levels of IFN-gamma, IL-13, and IL-4 in the culture supernatants were measured using enzymatic immunoassaying. IFN-gamma production was detected in all cultures from nonallergic controls stimulated with IL-18 in the presence of IL-12; however, the results for five BA patients and five AD patients were under the detection limit for IFN-gamma. In collaboration with IL-2, IL-18 was able to induce IFN-gamma production by PBMCs from all nonallergic controls and all allergic patients, with the exception of one AD patient. Synergistic induction of IL-13 production was found in cultures with IL-18 + IL-2, and the IL-13 induction was significantly increased in BA patients when compared with that in nonallergic controls (P = 0.006). The stimulation by IL-18, even in combination with IL-2, failed to induce IL-4 production by PBMC from both nonallergic controls and allergic patients. Although the induction of IFN-gamma by IL-18 + IL-12 was impaired in around a quarter of the allergic patients, the impairment of the IFN-gamma production was completely restored by IL-2 in the presence of IL-18. Thus, IL-18 enhances IFN-gamma production through an IL-12-dependent pathway and exhibits synergism when combined with IL-2 in terms of enhanced IL-13 and IFN-gamma production, suggesting the involvement of IL-18/IL-12/IL-2 pathway in modulating Th1/Th2 cytokine response.     

EAACI Guidelines on Allergen Immunotherapy: House dust mite‐driven allergic asthma

Allergen immunotherapy (AIT) has been in use for the treatment of allergic disease for more than 100 years. Asthma treatment relies mainly on corticosteroids and other controllers recommended to achieve and maintain asthma control, prevent exacerbations, and improve quality of life. AIT is underused in asthma, both in children and in adults. Notably, patients with allergic asthma not adequately controlled on pharmacotherapy (including biologics) represent an unmet health need. The European Academy of Allergy and Clinical Immunology has developed a clinical practice guideline providing evidence‐based recommendations for the use of house dust mites (HDM) AIT as add‐on treatment for HDM‐driven allergic asthma. This guideline was developed by a multi‐disciplinary working group using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. HDM AIT was separately evaluated by route of administration and children and adults: subcutaneous (SCIT) and sublingual AIT (SLIT), drops, and tablets. Recommendations were formulated for each. The important prerequisites for successful treatment with HDM AIT are (a) selection of patients most likely to respond to AIT and (b) use of allergen extracts and desensitization protocols of proven efficacy. To date, only AIT with HDM SLIT‐tablet has demonstrated a robust effect in adults for critical end points (exacerbations, asthma control, and safety). Thus, it is recommended as an add‐on to regular asthma therapy for adults with controlled or partially controlled HDM‐driven allergic asthma (conditional recommendation, moderate‐quality evidence). HDM SCIT is recommended for adults and children, and SLIT drops are recommended for children with controlled HDM‐driven allergic asthma as the add‐on to regular asthma therapy to decrease symptoms and medication needs (conditional recommendation, low‐quality evidence).     

The effect of treatment with montelukast on in vitro interleukin-10 production of mononuclear cells of children with asthma

BACKGROUND: The effects of leukotriene modifiers on IL-10 production have not been studied in children with asthma. OBJECTIVE: The primary objective of this study was to determine the changes in IL-10 concentrations, clinical efficacy and peripheral blood eosinophil counts after treatment with montelukast. METHODS: The study was conducted on 27 patients: 13 patients monoallergic to grass pollen during the pollen season (GPs group) and out of the pollen season (GPos group), and on 14 patients monoallergic to house dust mite (HDM) from May to September (HDM group). Main outcome measures were changes in concentrations of IL-10 in the supernatant after a 4-week treatment with montelukast. Measurements of asthma severity score, forced expiratory volume in 1 s (FEV1) and peripheral blood eosinophil counts were the secondary end-points. RESULTS: Montelukast resulted in a within-group significant increase in IL-10 concentration in the supernatant in the GPs (54.0 vs. 125.5 pg/mL) and in the HDM (51.2 vs. 77.1 pg/mL) group. Montelukast had no effect on changes of IL-10 concentration in the supernatant from peripheral blood mononuclear cell (PBMC) culture after non-sensitizing allergen stimulation. Montelukast significantly improved asthma control and FEV1, and significantly decreased eosinophil blood count in the GPs and in the HDM group after a 4-week treatment. Montelukast did not lead to changes of all measured parameters within the GPos group. CONCLUSION: Montelukast increased IL-10 concentration in supernatants from sensitizing allergen-stimulated PBMC culture obtained from children with asthma monoallergic to grass pollen during the pollen season, and from children with asthma monoallergic to HDM.     

Effect of BCG vaccination on cytokine mRNA expression in atopic children with asthma

BACKGROUND: To investigate whether a preexisting T(H2)-type immune response could be suppressed by BCG immunization in atopic children with asthma. METHODS AND RESULTS: We have used PCR to amplify reverse transcribed (RT) IFN-gamma and IL-5 mRNA expressed by peripheral blood mononuclear cells (PBMCs) in response to in vitro phytohemagglutinin A, purified protein derivative and Dermatophagoides pteronyssinus II stimulation from nine atopic children, both before and 8 weeks after BCG vaccination. We have demonstrated that IFN-gamma expression was induced in response to all stimulants (IFN-gamma/beta-actin) after the vaccination, whereas there was no expression before (P<0.001). Although there was a tendency to diminish in the expression of IL-5 mRNA in response to the stimulants, only PHA rendered a statistically significant decrease after the vaccination. CONCLUSIONS: These results provide some evidence of TH1 dominance after BCG administration in atopic children.     

特异性免疫治疗对变应性鼻炎合并哮喘患儿的影响

目的: 探讨屋尘螨变应原特异性免疫治疗对变应性鼻炎合并哮喘患儿血清白细胞介素 13(IL-13)、白细胞介素 4(IL-4)、干扰素 γ(IFN-γ)水平及鼻部症状和肺功能的影响。方法: 选择屋尘螨变应原阳性的变应性鼻炎合并支气管哮喘的患儿58例,其中35例接受屋尘螨特异性免疫治疗为免疫组,其余23例予局部糖皮质激素治疗为药物组。于治疗前及治疗1年后分别测定患儿血清IL-4、IFN-γ和IL-13水平,并评估鼻部症状和肺功能。结果: 经过1年治疗后,免疫组鼻部症状评分较治疗前明显减少(P<0.05),与药物组相比有显著差异(P<0.05);免疫组因哮喘急性发作而急诊就诊的频率明显少于药物组;与治疗前比较,免疫组血清IL-4和IL-13水平下降,IFN-γ水平及IFN-γ/IL-4升高 (P<0.05),肺功能改善明显(P<0.05);而药物组血清IL-4和IL-13水平较治疗前无明显下降 (P>0.05),肺功能无改善 (P>0.05)。结论: 特异性免疫治疗后患儿血清IL-4和IL-13下调, IFN-γ及IFN-γ/ IL-4上调,提示特异性免疫治疗可能调节体内T辅助细胞(Th)Th1/Th2细胞的平衡,从而改善患儿鼻部症状和肺功能。     

Usefulness of specific immunotherapy in patients with severe perennial allergic rhinitis induced by house dust mite: a double-blind, randomized, placebo-controlled trial

OBJECTIVES: To evaluate the effectiveness of specific immunotherapy (SIT) in patients with severe house dust mite (HDM)-induced perennial allergic rhinitis using diary cards and objective endpoints. PATIENTS AND METHODS: Thirty-six adult patients were selected with moderate to severe allergic rhinitis due to HDM allergy uncontrolled by regular anti-allergic drugs. Twenty-eight patients completed the study, 22 of these patients also had mild asthma. Subjects were stratified for HDM sensitivity on the basis of their 4-week diary card score and the size of their immediate and late-phase skin reaction to HDM. The groups were well matched for all relevant parameters. Patients were randomized to receive active preparation (Alutard(R)-SQ, ALK, Dermatophagoides pteronyssinus extract) or an identical placebo preparation. Increasing doses were administered until the maintenance dose was reached. This dose was then given once a month for 12 months. RESULTS: Clinical efficacy was evaluated by symptom medication diary cards recorded for 4 weeks after 12 months of continuous treatment and compared with pre-treatment scores. Skin test reactivity was re-measured after 12 months of treatment to HDM, cat dander and codeine phosphate. After 1 year of treatment, the actively treated group showed a 58% reduction in diary card symptom scores (P<0.002) and a 20% reduction in the use of rescue medication. The placebo group had a 32% reduction in symptom scores (P=NS), but no reduction in rescue medication requirements. The active group showed 36% reduction in skin prick test sensitivity to D. pteronyssinus (P=0.006), while the placebo group values were unchanged. Skin reactivity to codeine was unchanged in both groups. No significant adverse reactions to SIT were encountered. CONCLUSIONS: One year of SIT for D. pteronyssinus in patients with poorly controlled rhinitis (+/-mild asthma) produced clinically useful improvement as shown by symptom-medication diary cards and reductions in immediate skin reactions compared with placebo treatment.     

CD4+ CD30+ T cells perpetuate IL-5 production in Dermatophagoides pteronyssinus allergic patients

BACKGROUND: Airway allergic diseases are regulated by interleukin (IL)-5, which causes infiltration of eosinophils into the bronchial epithelium, and by IL-4 which increases serum immunoglobulin E (IgE) production and promotes CD30 expression on Th cells. CD30 generates a costimulatory signal involved in apoptosis or cell proliferation, depending on the microenvironment. Our aims were: (i) to analyze if CD4+ CD30+ T cells from allergic patients proliferate in response to Dermatophagoides pteronyssinus, and (ii) if upon stimulation this cell population produces IL-4 and IL-5. METHODS: Peripheral blood mononuclear cell (PBMC) from 17 allergic rhinitis and mild allergic asthma patients and 12 healthy nonallergic individuals were stimulated with allergen in the presence or absence of anti-IL-4, anti-IL-5 or anti-IL-4Ralpha monoclonal antibodies (mAbs). TdT-mediated dUTP nick end-labeling (TUNEL) assay, 7-aminoactinomycin-D (7-AAD) intercalation, and flow cytometry were used to determine the CD4+ CD30+ blasts percentage, cell proliferation, apoptosis, and intracellular cytokines after 7 culture days. RESULTS: Cell proliferation induced with allergen showed that 90% of the allergen-stimulated blasts were CD4+, 50% of which were CD30+. Allergen-stimulated PBMC showed a progressive increase (mean: from 7% to 23%) of CD4+ CD30+IFN-gamma+ and CD4+ CD30+IL-4+ blasts which diminished (mean: 6%) after 5 culture days. In contrast, CD4+ CD30+IL-5+ blasts showed a continuous progression (from 12% to 24%) that maintained after 7 culture days. The vast majority of CD4+ CD30+ blasts were negative to 7-AAD or TUNEL. Additionally, a significant decrease (34%) was observed in the number of CD4+ CD30+ blasts when IL-4 was neutralized. CONCLUSIONS: These data suggest that specific allergen stimulation of PBMC isolated from allergic patients generates a nonapoptotic CD4+ CD30+ blast subset that produces IL-5.     

Clinical efficacy and immunological mechanisms of sublingual and subcutaneous immunotherapy in asthmatic/rhinitis children sensitized to house dust mite: an open randomized controlled trial

Background In children, the clinical efficacy and immunological mechanisms of sublingual immunotherapy (SLIT) compared with subcutaneous immunotherapy (SCIT) is still to be elucidated. Objectives To compare SLIT, SCIT and pharmacotherapy in relation to clinical efficacy and immunological mechanisms that govern its effect in asthmatic/rhinitis children who were sensitized to house dust mite (HDM). Methods In this single centre, prospective, randomized, controlled, open labelled, three parallel group trial, 48 patients mono‐sensitized to HDM were randomized to receive either SLIT (n=16), SCIT (n=16) or pharmacotherapy alone (n=16). Symptom, medication and visual analogue score (VAS) were collected and bronchial‐nasal hyper‐reactivity, skin prick tests, total‐specific IgE were performed at baseline and 12 months after treatment. In addition, peripheral blood mononuclear cells were cultured with recombinant Der p 1 and Bet v 1 extracts and allergen‐specific IL‐4, IL‐5, IL‐13, IFN‐γ, IL‐10, and TGF‐β secretions were measured. Results SLIT and SCIT demonstrated a significant reduction of total rhinitis and asthma symptom score, total medication score, VAS and skin reactivity to HDM (P<0.05) when compared with pharmacotherapy. A significant reduction of serum‐specific HDM‐IgE in SCIT and SLIT were observed. Moreover, titrated nasal provocative dose significantly increased in both immunotherapy groups when compared with the pharmacotherapy group. No adverse effects were reported in SLIT, while two patients demonstrated serious adverse events in SCIT. After 1 year of treatment, Der p 1‐driven IL‐10 significantly increased in SLIT compared with pharmacotherapy, whereas Bet v 1‐driven TGF‐β (negative control) increased significantly in SLIT only. No changes were observed for Th1–Th2 cytokines. Conclusion Both SLIT and SCIT demonstrated clinical improvement compared with pharmacotherapy in asthma/rhinitis children sensitized to HDM.     

Neonatal interleukin-12 capacity is associated with variations in allergen-specific immune responses in the neonatal and postnatal periods

BACKGROUND AND OBJECTIVES: A reduced capacity of antigen presenting cells (APC) to provide pro-T helper 1 (Th1) signals, such as IL-12, to T cells during early life may be implicated in the development of T helper 2 (Th2)-mediated allergic disease. In this study we examined the relationships between the capacity for IL-12 responses in the neonatal period and atopic risk (family allergy), in vitro T cell responses to allergens, and the subsequent development of allergic disease at 6 years. METHODS: The capacity of circulating neonatal (and maternal) APC to produce IL-12 p70 in response to LPS (and IFN-gamma) stimulation was assessed in a group of 60 children with previously well-characterized immune responses to allergens and atopic outcomes. The IL-12 responses were compared with allergen-induced lymphoproliferation (to house dust mite (HDM) ovalbumin (OVA), cat and beta-lactoglobulin (BLG)) and IL-13 and IFN-gamma cytokine responses (to OVA, HDM and phytohaemaglutinin (PHA)) in the neonatal and postnatal periods. IL-12 responses were also compared according to atopic risk and atopic outcomes (doctor-diagnosed asthma, eczema, food allergies and sensitization as evidenced by skin prick testing) at 6 years clinical follow-up. RESULTS: Maternal peripheral blood mononuclear cells (PBMC) synthesized significantly greater amounts of IL-12 than neonatal PBMC, though within maternal-infant pairs IL-12 responses were significantly correlated (r = 0.4, P = 0.019). Moreover, neonatal IL-12 responses were positively correlated with neonatal allergen proliferation for HDM (r = 0.6, P < 0.0001), OVA (r = 0.55, P < 0.0001), cat (r = 0.5, P = 0.003) and BLG (r = 0.55, P = 0.001), but negatively correlated with neonatal IL-13 responses to both allergens tested (HDM: r = - 0.4, P = 0.03 and OVA: r = - 0.5, P = 0.001). Both neonatal and maternal IL-12 responses were positively correlated with postnatal IFN-gamma responses to HDM at 12, 18 and 24 months of age (responses after age of 2 years were not assessed). There was no relationship between atopic risk and IL-12 capacity in the neonatal period, but there was a (non-significant) trend for neonatal IL-12 responses to be lower in the high-risk children who developed clinical allergy at 6 years (compared with the low risk group) although the number in this analysis was small. CONCLUSIONS: Reduced APC IL-12 production in the perinatal period was associated with reduced T cell activation (lymphoproliferation), stronger neonatal Th2 responses, and weaker Th1 responses to allergen in the postnatal period. This supports the notion that variations in APC function in early life may contribute to altered allergen-specific cytokine responses associated with later allergy.     

Allergen-induced interleukin-9 production in vitro: correlation with atopy in human adults and comparison with interleukin-5 and interleukin-13

BACKGROUND: The contribution of IL-9 to human atopy is supported by genetic studies. However, IL-9 production in response to allergen in vitro has been reported only in children. OBJECTIVE: Study IL-9 induction by allergen in adults, compare it with IL-5 and IL-13 and evaluate its association with atopy. METHODS: Peripheral blood mononuclear cell (PBMC) from control adults and from atopic patients were cultured with various allergens or phytohaemagglutinin (PHA) and secreted IL-5, IL-9 and IL-13 were measured by ELISA. RESULTS: IL-9 was produced in response to Dermatophagoides pteronyssinus (Der p) by PBMC from Der p-hypersensitive adults at levels equivalent to those induced by PHA but with slower kinetics. The induction of IL-9 was allergen specific, reflecting donor RAST profile. In Der p-triggered reactions of non-atopic and atopic subjects, IL-9 showed the highest selectivity for atopics, IL-5 and IL-13 being produced more frequently in non-atopic donors. Significant correlations with specific IgE titres were found for IL-9 with all allergens tested (Der p and two peptides of Bet v 1 birch allergen). For IL-5 and IL-13, they were in the same range for Der p but more variable for birch allergens. Patterns of cytokine production by individual patients in response to allergen reflected these differences: for Der p, IL-5, IL-9 and IL-13 productions were strongly correlated but for birch IL-5 differed from the latter two. The in vitro production of IL-9 reflected clinical hypersensitivity profiles and was higher in individuals with asthma than in those with disease limited to rhinitis and/or conjunctivitis. CONCLUSIONS: Allergen-triggered IL-9 production in vitro is an excellent marker for atopy in adults given its virtual absence in allergen-stimulated PBMC from non-atopic individuals and its correlation with allergen-specific IgE and asthma.     

Clinical improvement and immunological changes in atopic dermatitis patients undergoing subcutaneous immunotherapy with a house dust mite allergoid: a pilot study

BACKGROUND: House dust mites (HDMs) represent significant indoor allergen sources for patients with atopic dermatitis (AD). Subcutaneous allergen-specific immunotherapy (SCIT) has been shown to be successful in patients with allergic rhinitis and mild asthma and might represent an attractive therapeutic option for the long-term treatment of HDM sensitizations in AD patients. However, only a few studies have been conducted on the effectiveness of HDM SCIT in AD, resulting in controversial clinical results. Data on immunological changes induced by SCIT in AD patients are rare. OBJECTIVES: We performed an open pilot study to assess clinical changes and objective laboratory parameters and evaluate the benefit of HDM SCIT in 25 AD patients with IgE-mediated sensitization against HDM. METHODS: The severity of AD was evaluated by the severity scoring of atopic dermatitis system (SCORAD). Specific IgE and IgG4 against HDM and serum levels of TARC/CCL17, MDC/CCL22, IL-16, IL-4, IFN-gamma, IL-10 and TGF-beta1 were measured during SCIT. RESULTS: Subjective and objective SCORAD improved significantly within only 4 weeks of treatment. The level of the tolerogenic cytokine IL-10 increased, whereas CCL17 and IL-16 decreased in the sera of the patients during SCIT. Allergen specific IgE decreased, while IgG4 increased during SCIT. CONCLUSION: In this open-label pilot study, SCIT with an HDM extract in patients with AD led to a significant improvement of AD mirrored by a reduction of SCORAD as well as serological and immunological changes, which might serve as valuable parameters to estimate the therapeutic effect of SCIT.     

IL-16 inhibits IL-5 production by antigen-stimulated T cells in atopic subjects

BACKGROUND: We have previously shown increased expression of the CD4+ cell chemoattractant IL-16 at sites of airway allergic inflammation. Little is known about the significance of IL-16 in allergic inflammation and its role in allergen-driven T-cell cytokine responses. Because IL-16 interacts specifically with CD4+ T cells, we hypothesized that IL-16 released at sites of inflammation may modulate the pattern of cytokines produced by CD4+ T cells. OBJECTIVE: We investigated the effects of exogenous rhIL-16 on cytokine production of PBMCs from atopic and nonatopic subjects in response to antigen and PHA. METHODS: Primary cultures of freshly isolated PBMCs from ragweed-sensitive atopic subjects and nonatopic subjects were stimulated with ragweed or PHA in the presence or absence of rhIL-16. Supernatant levels of IL-4, IL-5, and IFN-gamma were determined by means of ELISA at different time points between 2 and 6 days. Effects of IL-16 on antigen-induced cellular proliferative responses were determined. RESULTS: No IL-4 protein was detected after antigen stimulation of PBMCs from atopic subjects, whereas significant levels of IL-5 were measured on day 6 (median, 534.9 pg/mL). IL-5 secretion was abolished in PBMC cultures depleted of CD4+ cells. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly reduced the amount of IL-5 released (median, 99.8 pg/mL; P <.001). Detectable levels of IFN-gamma (median, 53.3 pg/mL) were identified after antigen stimulation. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly increased IFN-gamma levels (median, 255.6 pg/mL; P <.05). Effects of rhIL-16 appear to be specific for antigen-stimulated PBMCs in atopic subjects because rhIL-16 did not alter IL-5 or IFN-gamma production in response to PHA nor did rhIL-16 alter cytokine production in nonatopic normal subjects. CONCLUSION: These studies suggest that IL-16 can play a role in regulating the production of cytokines seen in allergic states in response to antigen.