Background: mycobacterial cells contain complex mixtures of mycolic acid esters. These can be used as antigens recognised by antibodies in the serum of individuals with active tuberculosis, caused by Mycobacterium tuberculosis. In high burden populations, a significant number of false positives are observed; possibly these antigens are also recognised by antibodies generated by other mycobacterial infections, particularly ubiquitous ‘environmental mycobacteria’. This suggests similar responses may be observed in a low burden TB population, particularly in groups regularly exposed to mycobacteria. Methods: ELISA using single synthetic trehalose mycolates corresponding to major classes in many mycobacteria was used to detect antibodies in serum of individuals with no known mycobacterial infection, comprising farmers, abattoir workers, and rural and urban populations. Results: serum from four Welsh or Scottish cohorts showed lower (with some antigens significantly lower) median responses than those reported for TB negatives from high-burden TB populations, and significantly lower responses than those with active TB. A small fraction, particularly older farmers, showed strong responses. A second study examined BCG vaccinated and non-vaccinated farmers and non-farmers. Farmers gave significantly higher median responses than non-farmers with three of five antigens, while there was no significant difference between vaccinated or non-vaccinated for either farmer or non-farmer groups. Conclusions: this initial study shows that serodiagnosis with mycobacterial lipid antigens can detect antibodies in a population sub-group that is significantly exposed to mycobacteria, in an assay that is not interfered with by vaccination. Given the links between mycobacterial exposure and a range of immune system diseases, further understanding such responses may provide a new opportunity for monitoring public health and directing treatment.

中文翻译：

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英国农民对合成分枝杆菌脂质抗原的血清抗体反应升高：是否表明暴露于环境分枝杆菌？

背景：分枝杆菌细胞含有分枝杆菌酸酯的复杂混合物。这些可用作由结核分枝杆菌引起的活动性结核病患者血清中抗体识别的抗原。在高负担人群中，观察到大量误报；可能这些抗原也被其他分枝杆菌感染产生的抗体识别，特别是无处不在的“环境分枝杆菌”。这表明在低负担结核病人群中可能会观察到类似的反应，特别是在经常接触分枝杆菌的人群中。方法：ELISA 使用与许多分枝杆菌中的主要类别相对应的单一合成海藻糖分枝杆菌来检测没有已知分枝杆菌感染的个体血清中的抗体，这些个体包括农民、屠宰场工人以及农村和城市人口。结果：来自四个威尔士或苏格兰队列的血清显示出比高负担 TB 人群的 TB 阴性报告更低（一些抗原显着更低）的中值反应，并且显着低于活动性 TB 的反应。一小部分人，尤其是年长的农民，表现出强烈的反应。第二项研究检查了 BCG 接种和未接种疫苗的农民和非农民。对于五种抗原中的三种，农民的反应中值明显高于非农民，而农民或非农民组在接种疫苗或未接种疫苗之间没有显着差异。结论：这项初步研究表明，分枝杆菌脂质抗原的血清学诊断可以在不受疫苗接种干扰的检测中检测明显暴露于分枝​​杆菌的人群亚组中的抗体。鉴于分枝杆菌暴露与一系列免疫系统疾病之间存在联系，进一步了解此类反应可能为监测公共卫生和指导治疗提供新的机会。