Grass Pollen-induced Asthma Research Articles

Long-term comparison of sublingual immunotherapy vs inhaled budesonide in patients with mild persistent asthma due tograss pollen

Few studies have compared the effects of immunotherapy and inhaled steroids. The main limitation of such studies is the long duration required to fully appreciate the effects of immunotherapy. To compare the effects of inhaled budesonide and sublingual immunotherapy (SLIT) in mild persistent asthma for up to 5 years. Patients with mild persistent asthma and rhinitis due to grass pollen were enrolled in an open randomized controlled trial. After a run-in season, they were randomized to either budesonide, 800 microg/d, in the pollen season or continuous grass SLIT for 5 years. All patients received rescue medications. Symptoms were evaluated by diary cards filled out from May to July at baseline and after 3 and 5 years. In-season nasal eosinophils and bronchial hyperresponsiveness were also assessed. Fifty-one patients were enrolled and 46 completed the study. The bronchial symptom scores and the use of bronchodilators decreased significantly in both groups, but the improvement was greater in the SLIT patients at 3 and 5 years. The nasal symptom score and the intake of nasal steroids decreased only in the SLIT group, and the difference vs the budesonide group was always significant. In the SLIT group vs the budesonide group, a statistically significant decrease of nasal eosinophils was found at 3 and 5 years (P < .01). The bronchial hyperresponsiveness improved significantly only in the SLIT group. In patients with grass pollen-induced asthma, in the long term SLIT was equally effective as inhaled budesonide in treating bronchial symptoms and provided an additional benefit in treating rhinitis symptoms and bronchial hyperresponsiveness.

Grass Pollen Immunotherapy as an Effective Therapy for Childhood Seasonal Allergic Asthma

Roberts G, Hurley C, Turcanu V, Lack G. J Allergy Clin Immunol. 2006;117:263–268 PURPOSE OF THE STUDY. There is abundant evidence to support the use of specific immunotherapy (SIT) in the treatment of allergic rhinoconjunctivitis. Studies that have looked at the role of SIT for the treatment of seasonal allergic asthma are lacking. This study evaluated the safety and effectiveness of SIT for the treatment of seasonal allergic asthma in children. STUDY POPULATION. A total of 39 of 161 screened subjects 3 to 16 years old were enrolled onto the study from the allergy clinic at St Mary's Hospital (London, United Kingdom). All of them had history of grass-pollen–induced asthma that required 200 μg of inhaled beclomethasone (or equivalent) daily. All subjects had a positive skin-prick–test response: a positive specific immunoglobulin E level (Pharmacia CAP) to a relevant grass pollen (Phleum pratense). Subjects also had a positive conjunctival provocation test. Subjects were excluded if they previously had been treated with grass-pollen immunotherapy or had a history of perennial asthma requiring inhaled corticosteroids, significant perennial allergic rhinitis, or sensitization to a pet present in the household. METHODS. The study was a single-center, randomized, double-blind, placebo-controlled study over 2 successive pollen seasons. Subjects were randomly assigned to receive SIT or placebo. The primary outcome was the asthma-symptom–medication score during the second pollen season. Secondary outcome measures included lung function, cutaneous, conjunctival, and bronchial allergen reactivity, and both exhaled nitric oxide and sputum eosinophil levels. RESULTS. The use of SIT was associated with a substantial reduction in asthma-symptom–medication score as compared with placebo (P = .04). There was significant reduction in cutaneous (P = .002), conjunctival (P = .02), and bronchial (P = .01) reactivity to allergen after SIT compared with placebo. Children in the 2 groups had similar levels of airway inflammation, although less inhaled steroids were required for those in the active group. No serious adverse events were reported, and no subjects withdrew because of adverse events. CONCLUSIONS. SIT is effective and well tolerated in children with seasonal allergic asthma to grass pollen. REVIEWER COMMENTS. There are limited studies that have demonstrated the efficacy of immunotherapy for treatment of asthma. On the basis of the complex nature of asthma and realizing that multiple phenotypes exist, it is understandable that there is difficulty in evaluating SIT for asthma. This study provided encouraging evidence for the role of SIT in the treatment of seasonal allergic asthma. Unfortunately, the majority of allergic patients are sensitized to multiple allergens, and symptoms are typically triggered by several different allergens.

Prophylactic treatment of grass pollen‐induced asthma with cetirizine

In a double-blind randomized parallel-group study, six investigators enrolled 43 subjects to study the prophylactic effect of 10 mg cetirizine b.i.d. on grass pollen-induced asthma. The control group received 60 mg b.i.d. terfenadine, given to avoid withdrawals from the trial because of hay fever symptoms. Subjects were included in the study between the appearance of the first symptoms of hay fever and those of pollen-induced asthma. The hay fever and asthma symptoms, visual analogue scores (VAS), FEV1 and self-assessment data on complaints, salvage treatment and peak-flow values were statistically analysed. Both treatments were well tolerated, with a low and similar incidence of side-effects. During the last 3 weeks of treatment, six (32%) of the 19 subjects on cetirizine who were evaluable for efficacy remained free of asthma complaints, and another two (10%) had only a single minor attack. None had a grade 3 (incapacitating) attack. Conversely, only one (5%) of the 20 evaluable subjects on terfenadine remained complaint free, and all others (95%) had multiple attacks, which incapacitated three (15%) of them. Nasal obstruction, dyspnoea, morning peak flow, consumption of beta 2-mimetics and an efficacy index on asthma, combining complaints and rescue drug consumption, were significantly better on cetirizine (P less than 0.05). It is concluded that cetirizine is able to prevent the exacerbation of asthma induced by grass pollen.

Grass pollen immunotherapy: A single year double-blind, placebo-controlled study in patients with grass pollen-induced asthma and rhinitis

Fifteen grass pollen--sensitive asthmatic patients were selected from 200 patients with grass pollenosis on the basis of positive SPTs and RASTs that were restricted to grass pollens (except Bermuda grass), no previous IT, and residence and occupation in an area monitored by serial pollen counts. They underwent a double-blind trial of specific IT with a mixture of three grass pollen--aqueous extracts (velvet, sweet vernal, and timothy) or placebo. After 10 mo, the mean maintenance dose of pollen extract (assayed by RAST inhibition) in eight actively treated patients was 6000 RAST units (range 3000 to 8000) and the mean total dose was 18,700 RAST units (range 10,200 to 30,000). Results were assessment done by the following clinical and immunological data: (1) during the pollen season, daily symptom scores; (2) PD 20% FEV1, IgE antibody to timothy by RAST in serum and in nasal secretions, serum IgG antibody to purified timothy allergen D by solid-phase radioimmunoassay, and the four IgG subclass antibodies by enzyme immunoassay were all measured before treatment and before and after the pollen season. Symptom scores of both treated patients and controls correlated with pollen counts (R = 0.88, p less than 0.05 and R = 0.71, p less than 0.05, respectively). There was a significant difference between the mean symptom score values of treated patients versus controls (Kruskal-Wallis test, p less than 0.001). No significant differences or changes either in the PD 20% FEV1 or IgE antibody to timothy in serum and nasal secretions were found in the two groups before or after IT.(ABSTRACT TRUNCATED AT 250 WORDS)