Efficacy and Safety of a Pressurized Metered-Dose Inhaler in Older Asthmatics: Comparison to a Dry Powder Inhaler in a 12-Week Randomized Trial

PURPOSE: Asthma control in older asthmatics is often less effective, which may be attributed to small airway dysfunction and poor inhalation technique. We compared the efficacy of 2 inhalers (fluticasone propionate/formoterol treatment using a pressurized metered-dose inhaler [p-MDI group] vs. fluticasone propionate/salmeterol treatment using a dry powder inhaler [DPI group]) in older asthmatics.METHODS: We conducted a 12-week, randomized, open-label, parallel-designed trial in older patients (over 55 years old) with moderate-to-severe asthma, and compared the efficacy and safety for asthma control between the 2 groups. Subgroup analyses on disease duration and air trapping were performed. Clinical parameters, including changes in lung function parameters, inhaler technique and adherence, were compared with monitoring adverse reactions between the 2 groups.RESULTS: A total of 68 patients underwent randomization, and 63 (30 in the p-MDI group and 33 in the DPI group) completed this study. The p-MDI group was non-inferior to the DPI group with regard to the rate of well-controlled asthma (53.3% vs. 45.5%, P < 0.001; a predefined non-inferiority limit of 17%). In subgroup analyses, the proportion of patients who did not reach well-controlled asthma in the p-MDI group was non-inferior to that in the DPI group; the difference was 12.7% among those with a longer disease duration (≥ 15 years) and 17.5% among those with higher air-trapping (RV/TLC ≥ 45%), respectively (a predefined non-inferiority limit of 17%, P < 0.001). No significant differences were observed in lung function parameters, inhalation techniques, adherence and adverse reactions between the 2 groups.CONCLUSION: These results suggest that the p-MDI group may be comparable to the DPI group in the management of older asthmatics in aspects of efficacy and safety.

A Retrospective Study of Clinical Response Predictors in Subcutaneous Allergen Immunotherapy With House Dust Mites for Allergic Rhinitis

PURPOSE: House dust mites (HDM) are major allergens that cause allergic rhinitis (AR). Allergen-specific subcutaneous immunotherapy (SCIT) has been shown to be clinically beneficial in many clinical trials. Such trials, however, are not reflective of all patient populations. The aim of this study was to describe the efficacy and safety of SCIT in routine clinical practice in Korean adults with AR sensitized to HDM. METHODS: We reviewed medical records of 304 patients with AR treated at an allergy clinic of a tertiary hospital using SCIT with aluminum hydroxide-adsorbed allergen extract targeting HDM alone or with pollens for at least 1 year from 2000 to 2012. Patients with asthma were excluded. Rates of remission, defined as no further requirement of maintenance medication, over time were determined by means of life tables and extension of survival analysis. Specific immunoglobulin E (IgE) levels to HDM were categorized into 6 classes. RESULTS: The mean time until achieving remission was 4.9±0.1 years, and the cumulative incidence of remission from AR was 76.6%. Severe AR (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.23-0.69; P=0.001), specific IgE levels to HDM ≥17.5 kU/L (OR, 1.85; 95% CI, 1.01-3.37; P=0.045), and duration of immunotherapy ≥3 years (OR, 7.37; 95% CI, 3.50-15.51; P<0.001) were identified as significant predictors of clinical remission during SCIT for patients with AR sensitized to HDM. Overall, 73 patients (24.0%) experienced adverse reactions to SCIT, and only 1 case of anaphylaxis (0.3%) developed. CONCLUSIONS: SCIT with HDM was found to be effective and safe for patients with AR. Specific IgE levels to HDM and a duration of SCIT ≥3 years may be predictors of clinical responses to SCIT in AR patients.

Subcutaneous Immunotherapy for Allergic Asthma in a Single Center of Korea: Efficacy, Safety, and Clinical Response Predictors

Allergen-specific immunotherapy is the only causal treatment for allergic diseases. However, the efficacy of immunotherapy may vary around the world due to differences in climate, the nature of aero-allergens and their distribution. The aim of this study was to describe the effects of subcutaneous immunotherapy (SCIT) in Korean adults with allergic asthma (AA). As a retrospective cohort study, we reviewed medical records for 627 patients with AA in Korea who were sensitized to house dust mite (HDM) and/or pollens and who underwent SCIT with aluminum hydroxide adsorbed allergen extract from 2000 to 2012. Rates of remission, defined as no further requirement of maintenance medication, over time were determined by means of life tables and extension of survival analysis. Herein, 627 asthmatic patients achieved remission within a mean of 4.7 ± 0.2 years. The cumulative incidence rates of remission from AA were 86.9% upon treatment with SCIT. Baseline forced expiratory volume in the first second (FEV1) ≥ 80% (hazard ratio [HR], 3.10; 95% confidence interval [CI], 1.79–5.39; P < 0.001), and maintenance of immunotherapy for more than 3 years (HR, 1.82; 95% CI, 1.21–2.72; P = 0.004) were significant predictors of asthma remission during SCIT. In 284 patients on SCIT with HDM alone, initial specific immunoglobulin E (IgE) levels to Dermatophagoides pteronyssinus and Dermatophagoides farinae did not show significant difference between remission and non-remission group after adjusting demographic variables. In conclusion, SCIT was effective and safe treatment modality for patients with AA. Initial FEV1 ≥ 80% and immunotherapy more than 3 years were found to be associated with favorable clinical responses to SCIT.

Effect of Interleukin-18 Gene Polymorphisms on Sensitization to Wheat Flour in Bakery Workers

Lower respiratory symptoms in bakery workers may be induced by wheat flour and endotoxins. We hypothesized that endotoxins from wheat flour may stimulate innate immunity and that interleukin-18 (IL-18) gene polymorphisms may affect their regulatory role in innate immune responses to endotoxins. To investigate the genetic contribution of IL-18 to sensitization to wheat flour, we performed a genetic association study of IL-18 in Korean bakery workers. A total of 373 bakery workers undertook a questionnaire regarding work-related symptoms. Skin prick tests with common and occupational allergens were performed and specific antibodies to wheat flour were measured by ELISA. Three polymorphisms of the IL-18 gene (-607A/C, -137G/C, 8674C/G) were genotyped, and the functional effects of the polymorphisms were analyzed using the luciferase reporter assay. Genotypes of -137G/C (GC or CC) and haplotype ht3 [ACC] showed a significant association with the rate of sensitization to wheat flour. Luciferase activity assay indicated ht3 [AC] as a low transcript haplotype. In conclusion, the regulatory role of IL-18 in lipopolysaccharide-induced responses in bakery workers may be affected by this polymorphism, thus contributing to the development of sensitization to wheat flour and work-related respiratory symptoms.