Search

Background: Pediatric allergic rhinitis (AR), including cedar pollinosis (CP), is increasing in Japan. We investigated the effects of sublingual immunotherapy (SLIT), which has limited studies of its effectiveness in real‐world settings, on children with CP. Methods: This retrospective cohort study used a claim database in 2018–2021. Children aged ≤15 years with CP records in 2019 were eligible and were followed up through 2021. We included 2962 CP children undergoing SLIT and 547 who were not. The medication score was used to evaluate SLIT effectiveness in the cedar pollen dispersal season each year. Adverse events and the occurrence of allergic diseases were also evaluated. Results: Medication score was higher in the SLIT group during the index period but lower in 2021 compared to the non‐SLIT group (mean ± standard deviation: 5.17 ± 2.39 and 4.74 ± 2.38 in 2019, 3.13 ± 2.30 and 3.55 ± 2.48 in 2021, respectively). The adjusted mean difference between groups from 2019 to 2021 was −0.62 (95% confidence interval: −0.86 to −0.39, p <.0001), and the medication score was reduced in the SLIT group (risk ratio: 1.2: 1.1 to 1.3). The occurrence of adverse events involving abdominal disorders (adjusted odds ratio [aOR]: 0.64: 0.51 to 0.81), asthma exacerbation (aOR: 0.37: 0.24 to 0.57), and allergic diseases involving hay fever unrelated to CP (aOR: 0.60: 0.45 to 0.80) or asthma (aOR: 0.71: 0.58 to 0.86) was lower in the SLIT group. Conclusion: In children with CP, SLIT is effective, well tolerated, and could decrease the occurrence of other allergic diseases. [ABSTRACT FROM AUTHOR]

Background Patients allergic to pollen have been known to become more symptomatic during pollen season compared with the nonpollen season. However, there are few studies regarding whether higher exposure to pollen might increase the prevalence of allergic diseases. Methods An ecological analysis was conducted to evaluate whether pollen exposure is associated with the prevalence of allergic diseases in schoolchildren. Pollen count data of Japanese cedar ( Cryptomeria japonica) and Japanese cypress ( Chamaecyparis obtusa), which are the major pollen allergens in Japan, were obtained from each prefecture. The prevalence of allergic diseases in schoolchildren in each prefecture was based on a nationwide cross-sectional survey using the International Study of Asthma and Allergies in Childhood questionnaire. Results After omitting three prefectures where pollen data were not available, data of 44 prefectures were analysed. The prevalence of allergic rhinoconjunctivitis in children aged 6-7 years was positively associated with both cedar and cypress pollen counts ( P = 0.01, both), whereas the prevalence of allergic rhinoconjunctivitis in children aged 13-14 years was positively associated with only cypress pollen counts ( P = 0.003). Furthermore, the prevalence of asthma was positively associated with cedar pollen counts in 6- to 7-year-old children ( P = 0.003) but not cypress pollen counts in either age group. Conclusions There are ecological associations between pollen counts and the prevalence of allergic diseases in Japanese schoolchildren. Further studies are needed to determine whether the difference between the effects of cedar and cypress pollens is attributable to pollen counts or allergenicity. [ABSTRACT FROM AUTHOR]

Background B7-1 (CD80) and B7-2 (CD86), which are costimulatory molecules in T-cell activation, play important roles in the differentiation of TH1- or TH2-phenotypes. These molecules were also suggested to play important roles in sensitization to a cedar pollen antigen by blocking studies using neutralizing antibodies, but there have been very few studies concerning the effects following induction by antigen. Objective In this study, we investigated the roles of B7-1 and B7-2 in the differentiation of TH1 and TH2 subsets after stimulation with the antigen in subjects with cedar pollinosis. Methods Skin-prick test was performed in nine subjects with pollinosis and in nine normal controls. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with Japanese cedar pollen extract. After in vitro stimulation, the expression of CD80 and CD86 on CD19+ cells was analysed by two-colour flow cytometry. Culture supernatants were collected for all subjects and the production of type 1 and type 2 cytokines was measured by ELISA. Results After in vitro stimulation, the expression of CD80 (B7-1) was upregulated in both pollinosis and control subjects, but no significant difference was observed between the two groups. On the other hand, CD86 (B7-2) was significantly upregulated following stimulation in pollinosis subjects (P = 0.02). A significantly higher level of IL-5 (P = 0.04) was produced by PBMCs of pollinosis subjects than by those of normal controls. A significantly higher level of interferon (IFN)-γ (P = 0.03) was produced by PBMCs of normal controls than by those of pollinosis subjects. Conclusion These results indicated that TH2 response was predominant in pollinosis subjects, and that CD19+ cells of pollinosis subjects expressed higher levels of B7-2 than those of control subjects after in vitro stimulation. In pollinosis subjects, B7-2 rather than B7-1 may be the costimulatory molecule involved in allergen-induced... [ABSTRACT FROM AUTHOR]

This article focuses on the impact of the environment on allergic lung diseases. Episodes of severe air pollution, particularly by acid aerosols and sulphur dioxide resulting from excessive burning of coal, frequently resulted in substantial morbidity and mortality from respiratory disease during the first few decades of this century. However, studies from Japan have demonstrated that the incidence of rhinoconjunctivitis in residents living alongside old cedar tree-lined main roads with heavy traffic all day long was much higher than that in residents living in the cedar forest but with less traffic, despite the cedar pollen counts being similar in both areas.