Allergen immunotherapy and respiratory infections in children: an encouraging experience.

BACKGROUND: Allergic inflammation may promote respiratory infections (RI). House dust mite (HDM) sensitization is common in childhood. Allergen immunotherapy may cure allergy as it restores a physiological immune and clinical tolerance toward the causal allergen and exerts anti-inflammatory activity. This study retrospectively investigated whether 3 year high-dose HDM-sublingual immunotherapy (SLIT) could affect respiratory infections in children with allergic rhinitis. METHODS: Globally, 33 HDM allergic children (18 males, mean age 9.3 years) were subdivided in 2 groups: 20 treated with symptomatic drugs alone (group 1) and 13 by high-dose SLIT, titrated in mcg of major allergens (group 2) for 3 years. RESULTS: SLIT-treated children had significantly (P=0.01) less RI episodes (3.6) than symptomatically-treated children (5.4). In addition, SLIT-treated children had less fever (P<0.01) and took fewer medications, such as antibiotics (P<0.05) and fever-reducers (P<0.01), than symptomatically-treated children. CONCLUSIONS: This preliminary study suggests that high-dose 3-year SLIT might lessen RI in allergic children.

In children allergic to ragweed pollen, nasal inflammation is not influenced by monosensitization or polysensitization.

BACKGROUND: In patients polysensitized to pollen allergens, the priming effect, by which the sensitivity of the nasal mucosa to an allergen is increased by the previous exposure to another allergen, is a known phenomenon. This study was aimed at evaluating the degree of nasal inflammation, assessed by nasal cytology, in children with allergic rhinitis (AR) from ragweed pollen according to being monosensitized or polysensitized. METHODS: The study included 47 children. Of them, 24 suffered from AR caused by sensitization to grass pollen and ragweed pollen (group A) and 23 were sensitized only to ragweed pollen (group B). In all patients, the severity of AR was assessed according to the Allergic Rhinitis and Its Impact on Asthma guidelines, and comorbidities were also evaluated. RESULTS: In group A, 16.7% of children had a mild intermittent AR, 4.2% a moderate-to-severe intermittent, 33.3% a mild persistent, and 45.8% a moderate-to-severe persistent; in group B, 26.1% of children had a mild intermittent AR, 0% a moderate-to-severe intermittent, 52.2% a mild persistent, and 21.7% a moderate-to-severe persistent. No significant difference was detected in the number of the considered comorbidities between the two groups. The cell counts of neutrophils, eosinophils, lymphocytes/plasma cells, and mast cells were high but not significantly different in the two groups. CONCLUSION: These findings show that the degree of nasal inflammation found in children with ragweed-induced AR is not influenced by additional allergy to grass pollen and confirm the previously reported absence of priming effect in ragweed allergy.

Effect of high-dose sublingual immunotherapy on respiratory infections in children allergic to house dust mite.

BACKGROUND: Allergic rhinitis is characterized by eosinophil inflammation. Allergic inflammation may induce susceptibility to respiratory infections (RI). House dust mite (HDM) sensitization is very frequent in childhood. Allergen immunotherapy may cure allergy as it restores a physiologic immune and clinical tolerance to allergen and exerts anti-inflammatory activity. OBJECTIVE: This study investigated whether six-month high-dose, such as 300 IR (index of reactivity), HDM-sublingual immunotherapy (SLIT) could affect RI in allergic children. METHODS: Globally, 40 HDM allergic children (18 males; mean age, 9.3 years) were subdivided in 2 groups: 20 treated by symptomatic drugs (group 1) and 20 by high-dose HDM-SLIT (group 2), since September 2012 to April 2013. The daily maintenance dose of HDM-SLIT was 4 pressures corresponding to 24, 4.8, and 60 µg, respectively of the major allergens Dermatophagoides pteronyssinus (Der p) 1, Der p 2, and Dermatophagoides farinae (Der f) 1. RI was diagnosed when at least 2 symptoms or signs, and fever were present for at least 48 hours. A family pediatrician provided diagnosis on a clinical ground. RESULTS: SLIT-treated children had significantly (p = 0.01) less RI episodes (3.5) than control group (5.45). About secondary outcomes, SLIT-treated children had less episodes of pharyngo-tonsillitis (p < 0.05) and bronchitis (p < 0.005), and snoring (p < 0.05) than control group. In addition, SLIT-treated children had less fever (p < 0.01) and took fewer medications, such as antibiotics (p < 0.05) and fever-reducers (p < 0.01), than control group. CONCLUSION: This preliminary study might suggest that also a short course (6 months) of high-dose SLIT, titrated in µg of major allergens, could reduce RI in allergic children.

Catching allergy by a simple questionnaire.

BACKGROUND: Identifying allergic rhinitis requires allergy testing, but the first-line referral for rhinitis are usually primary care physicians (PCP), who are not familiar with such tests. The availability of easy and simple tests to be used by PCP to suggest allergy should be very useful. METHODS: The Respiratory Allergy Prediction (RAP) test, based on 9 questions and previously validated by a panel of experts, was evaluated in this study. RESULTS: An overall number of 401 patients (48.6% males, age range 14-62 years) with respiratory symptoms was included. Of them, 89 (22.2%) showed negative results to SPT, while 312 (77.8%) had at least one positive result to SPT. Cohen's kappa coefficient showed that all questions had an almost perfect excellent agreement between pre and post-test. The algorithm of decision-tree growth Chi-squared Automatic Interaction Detector showed that answering yes to the question 4 (Your nasal/ocular complains do usually start or worsen during the spring?), 6 (Did you ever had cough or shortness of breath, even during exercise?) and 8 (Do you use nasal sprays frequently?) gave a probability to have a positive SPT of 85%. CONCLUSIONS: These findings show that RAP test can be proposed as an useful tool to be used by physician other than allergists when evaluating patients with rhinitis, suggesting the need of allergy testing.

Focusing the mechanism of action to dissect the different treatments of respiratory allergy.

The treatment of respiratory allergy is based on several drugs with different mechanisms of action, which encompass an effect only on symptoms, limited factors of inflammation or the whole process of inflammation. Dissecting the different treatments by their mechanism of action is relevant for the management of allergic patients. Corticosteroids, administered as nasal sprays in rhinitis or by inhalation devices in asthma, and allergen immunotherapy (AIT) are the most effective treatments for respiratory allergy, achieving the control on inflammation by a number of cellular and molecular mechanisms. What distinguishes corticosteroids from AIT is the duration of clinical outcomes that ends with treatment withdrawal for the former but persists after stopping for AIT, due to its disease-modifying effect.

Allergic rhinitis phenotypes based on mono-allergy or poly-allergy.

BACKGROUND: Allergic rhinitis (AR) is characterized by typical symptoms that are dependent on inflammation. Poly-allergy is a frequent phenomenon. Phenotyping AR represents an up-to-date issue. OBJECTIVE: The aim of this study was to evaluate whether the number of allergies is able to define different phenotypes in patients with AR. METHODS: 83 patients (43 males, mean age 34.7 years) suffering from AR were evaluated. Sensitization, VAS for nasal symptoms perception, and nasal cytology were evaluated. RESULTS: Poly-allergic patients perceived more severe nasal obstruction than mono-allergic ones (p = 0.0006) as well as they had more frequent sneezing (p < 0.0001). Moreover, poly-allergic patients had a more intense inflammatory infiltrate, concerning both eosinophils (p = 0.0005) and mast cells (p = 0.0001), than mono-allergic patients. CONCLUSIONS: The present study demonstrates that the presence of poly-allergy could define a distinct AR phenotype in comparison with mono-allergy. It could be clinically relevant as poly-allergic patients have more intense inflammation and more severe symptoms than mono-allergic ones.

Severity of allergic rhinitis and asthma development in children.

Allergic rhinitis (AR) is a relevant risk factor for the development of asthma in children. We recruited a cohort of 104 children with AR and re-evaluated them after 5 years. We considered the ARIA classification. All patients, who had moderate to severe persistent AR at baseline, developed asthma symptoms. These results strongly indicate that the severity of AR may be an important factor that increases the risk of asthma development in children.