Clinical and anti-inflammatory effects of ultra-short preseasonal vaccine to Parietaria in asthma

The ultra-short course preseasonal allergy vaccine, containing the adjuvant monophosphoryl lipid A (MPL), is effective in treating allergic symptoms; however, the efficacy in controlling asthmatics symptoms has not been fully demonstrated. We aimed at evaluating whether the ultra-short preseasonal course of immunotherapy contributes to asthma control. Four subcutaneous injections of the active product (Pollinex Quattro) were administered, before the pollen season, to 20 Parietaria-sensitive mild, untreated asthmatics (M/F: 12/8; age: 38 ± 14 years). After the screening visit (visit 1), asthma control was assessed by the Asthma Control Test (ACT) immediately before the first (visit 2) and immediately after the last (visit 5) injections, as well as during the pollen season (visit 6). Bronchial and alveolar exhaled nitric oxide (NO) concentrations were also measured. Nine Parietaria-sensitive mild asthmatics (M/F: 3/6; age: 40 ± 12 years) served as untreated controls. The ACT remained constant during allergen exposure in specific immunotherapy (SIT)-treated asthmatics (visit 2: 22 ± 3.2; visit 5: 23 ± 2.8; visit 6: 22 ± 3.6; analysis of variance [ANOVA], p = 0.47), whereas it dropped during pollen exposure in controls (visit 2: 20 ± 2.5; visit 5: 21 ± 2.8; visit 6: 16 ± 5.7; ANOVA, p = 0.01). The forced expiratory NO (FENO) values significantly increased during pollen exposure in both groups; however, the alveolar NO concentrations remained stable in SIT-treated asthmatics (p = 0.11), whereas they doubled in controls (p = 0.01). The current findings show that the preseasonal vaccine adjuvated with MPL contributes to the maintenance of control of asthma during the pollen season.