METHODS: The study included a total of 45 healthy male subjects of different age groups. Whole blood was collected from the subjects, and the concentration of myeloperoxidase (MPO), the main biocidal protein in NETs, was determined in serum using ELISA. The serum levels of circulating free DNA (cfDNA), which are the structural basis of NETs, were also measured by fluorescence. In addition, the white blood cell count was determined, whole blood smear was evaluated, and the neutrophillymphocyte ratio was calculated. The variations in the levels of NET biomarkers were analyzed in different age groups.
RESULTS: The low levels of MPO (243.70 ng/ml) and cfDNA (6.24 ng/100 μl) in boys indicated neutrophil insufficiency for NETosis in children. A progressive increase in the levels of MPO and cfDNA with age was observed among adolescents (420.91, p = 0.04; 13.55, p = 0.03, respectively), with the highest level noted in the healthy adult group (466.58, p = 0.01; 14.07, p = 0.01, respectively). The levels of the studied parameters were comparable in adolescents and young adults, which proved that the NETosis process was appropriate and suggested the attainment of neutrophil maturity for the release of NETs in adolescence. The levels of MPO and cfDNA were low in older men (225.46, p < 0.01; 5.19, p < 0.01, respectively) indicating impaired NET formation.
CONCLUSIONS: Data on the generation of NETs in different age groups obtained in this study can allow a better understanding of the ontogenesis of the immune system in terms of the course of NETosis, and also indicate the need to support nonspecific responses in children and adults. Further research should be performed to determine the possibility of regulating the NETosis process. Int J Occup Med Environ Health. 2023;36(3):333-48.
方法:本研究共纳入45名不同年龄段的健康男性受试者。从受试者身上采集全血,和髓过氧化物酶(MPO)的浓度,NET中的主要杀生物蛋白,使用ELISA在血清中测定。血清循环游离DNA(cfDNA)水平,这是NET的结构基础,还通过荧光测量。此外,测定了白细胞计数,对全血涂片进行了评估,并计算中性粒细胞比率。分析了不同年龄段NET生物标志物水平的变化。
结果:男孩中MPO(243.70ng/ml)和cfDNA(6.24ng/100μl)的低水平表明儿童NETosis中性粒细胞不足。在青少年中观察到MPO和cfDNA水平随年龄逐渐增加(分别为420.91,p=0.04;13.55,p=0.03),在健康成人组中,最高水平(分别为466.58,p=0.01;14.07,p=0.01)。所研究参数的水平在青少年和年轻人中具有可比性,这证明了NETosis过程是适当的,并建议在青春期达到中性粒细胞成熟度以释放NETs。老年男性的MPO和cfDNA水平较低(分别为225.46,p<0.01;5.19,p<0.01),表明NET形成受损。
结论:在这项研究中获得的有关不同年龄组NETs生成的数据可以更好地了解NETosis过程中免疫系统的本体发生,并指出需要支持儿童和成人的非特异性反应。应进行进一步的研究以确定调节NETosis过程的可能性。IntJOccupMedEnvironHealth。2023年;36(3):333-48。