We identified a negative association between pinworm infestation and allergic airway diseases, which could in part be attributed to protective effect of pinworm infestation on development of allergic symptoms. Other mechanisms of association could not be ruled out.

To elucidate the link between the intake of animal fat and asthma, a murine model was developed to examine the effect of dietary cholesterol on pulmonary allergic inflammation. Male C57BL6 mice were fed either a control diet or a diet supplemented with 2% cholesterol. Following sensitization and inhalation exposure to ovalbumin, the bronchoalveolar lavage fluid of mice in the cholesterol group contained higher numbers of eosinophils and elevated levels of IL-5, PGE(2), and MCP-1. In addition, dietary cholesterol also resulted in elevated production of IL-4 and IFN-gamma by lymphocytes isolated from the lungs. These inflammatory indicators were all significantly correlated with serum cholesterol levels. In contrast to the effect of dietary cholesterol, adding pravastatin to the drinking water significantly reduced eosinophil infiltration and the levels of IL-5, PGE(2) and MCP-1 in lavage fluid. Although dietary cholesterol did not alter baseline IL-12 in the lungs, in mice challenged with ovalbumin the IL-12 levels were reduced in the cholesterol group and elevated significantly in the pravastatin group. The results suggest that dietary cholesterol might enhance pulmonary allergic inflammation, possibly involving both nonspecific inflammatory processes and lymphocyte activities.

Background: Epidemiological studies have suggested that the dietary pattern may be associated with the prevalence of asthma. We previously reported that an increased intake of foods of animal origin was associated with the occurrence of allergic rhinitis and asthma in adolescents. Here we examined the effect of dietary cholesterol in a murine model of allergic pulmonary inflammation. Methods: Weanling C57BL/6 mice were fed a control diet containing 0.02% cholesterol or a diet supplemented with 1% or 2% cholesterol. Four weeks later the mice were sensitized with intraperitoneal ovalbumin (OVA) followed by OVA or saline inhalation 2 weeks later. OVA aerosol-induced inflammation was significantly enhanced by dietary supplementation of 1% or 2% cholesterol. Results: Among OVA-challenged mice, leukocyte numbers, particularly those of eosinophils, in the bronchoalveolar space increased by 3- to 5-fold with the cholesterol supplement. Among OVA aerosol-challenged mice, the levels of interleukin-5 and cysteinyl leukotrienes in the bronchoalveolar lavage fluid were significantly higher in those fed the 2% cholesterol diet compared with mice on the control diet. Conclusions: Dietary cholesterol may enhance pulmonary allergic inflammation.