Department of Public Health, Section for Environment, Occupation and Health, Aarhus University, Danish Ramazzini Center, Aarhus, Denmark.
National Research Centre for the Working Environment, Copenhagen, Denmark.
Occup Environ Med. 2018 Feb;75(2):139-147. doi: 10.1136/oemed-2017-104384. Epub 2017 Aug 23.
Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults.
The cohort consisted of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline. Sensitisation to birch pollen, grass pollen, cat dander and house dust mite was measured by specific IgE levels in serum samples from baseline and at 15 years' follow-up. Changes in sensitisation were analysed in relation to cumulative endotoxin exposure during follow-up, considering early life farm exposure.
Endotoxin exposure during follow-up was significantly associated with less new onset of specifically grass and birch pollen sensitisation. For the highest versus lowest quartile of cumulative endotoxin exposure, the OR for new-onset IgE sensitisation was 0.35 (0.13-0.91) for birch and 0.14 (0.05-0.50) for grass. On the other hand, loss of pollen sensitisation showed a positive, although mostly non-significant, association with increased levels of endotoxin exposure. Endotoxin exposure was not associated with significant changes in cat dander and house dust mite sensitisation.
High exposure to endotoxin during young adulthood appears to protect against new onset of pollen sensitisation, independent of childhood farm exposure.
成人中新发和丧失特应性致敏的风险因素知之甚少。本研究旨在检测定量评估内毒素暴露对青年成人中特定变应原致敏变化的纵向影响。
该队列包括 1113 名丹麦年轻农民和农村对照者，基线时的平均年龄为 19 岁。在基线和 15 年随访时，通过血清样本中的特异性 IgE 水平测量桦树花粉、草花粉、猫皮屑和屋尘螨的致敏情况。考虑到早期农场暴露，分析了致敏变化与随访期间累积内毒素暴露之间的关系。
随访期间的内毒素暴露与特异性草和桦树花粉致敏的新发率降低显著相关。对于累积内毒素暴露量最高和最低四分位数的比较，桦树的新发生 IgE 致敏的 OR 为 0.35（0.13-0.91），草的 OR 为 0.14（0.05-0.50）。另一方面，花粉致敏的丧失与内毒素暴露水平的增加呈正相关，但大多无统计学意义。内毒素暴露与猫皮屑和屋尘螨致敏的显著变化无关。
在成年早期，高水平的内毒素暴露似乎可预防花粉致敏的新发，且与儿童期农场暴露无关。
