人嗜酸细胞衰老相关改变的研究
2008/04/30
现已有对T细胞、巨噬细胞、中性粒细胞以及树状突细胞等免疫细胞功能衰老的研究，但却没有对嗜酸细胞的相关研究，就此，Sameer K. Mathur等人对嗜酸细胞进行了一些与衰老有关的变化的研究，并研究他们对哮喘的潜在意义。他们将哮喘受试者分成两个年龄组，年轻组（20～40岁）和年老组（55～80岁）。每个受试者都进行肺功能、诱导痰和外周血检验。从外周血中提出嗜酸细胞进行脱粒、合成超氧化离子、粘附和趋化等离体的功能活性检测。得出在年老组中嗜酸细胞脱粒随着IL-5刺激明显增多（p = 0.025）。老年组超氧负离子的嗜酸细胞产生随着卟啉醇肉豆蔻酸乙酸酯而减少，但差异不显著(p = 0.097)。两组中嗜酸细胞的粘附和趋化作用、肺功能以及痰中嗜酸细胞比例相仿，无明显差异。
由此得出，气道内嗜酸细胞的增多在两个年龄组中有可比性。尽管如此，在外周血嗜酸细胞“效应器”功能上，仍是存在与年龄相关的差别。例如，嗜酸细胞在哮喘中起着病理生理学方面的作用，由于其在炎症细胞功能中存在着一些与衰老相关的差异，而这些细胞功能影响着疾病的临床表现和对某些药品的反应性疗效，因此，嗜酸细胞在中年以上人群中可能有着重要的临床差异。
由此得出，气道内嗜酸细胞的增多在两个年龄组中有可比性。尽管如此，在外周血嗜酸细胞“效应器”功能上，仍是存在与年龄相关的差别。例如，嗜酸细胞在哮喘中起着病理生理学方面的作用，由于其在炎症细胞功能中存在着一些与衰老相关的差异，而这些细胞功能影响着疾病的临床表现和对某些药品的反应性疗效，因此，嗜酸细胞在中年以上人群中可能有着重要的临床差异。
（于娜 中国医科大学附属第一医院呼吸内科 110001 摘择）
(Chest.2008; 133:412-419)
Age-Related Changes in Eosinophil Function in Human Subjects*
Sameer K. Mathur, MD, PhD; Elizabeth A. Schwantes; Nizar N. Jarjour, MD, FCCP and William W. Busse, MD
Abstract
Background: Aging results in changes in immune cell function that have been described for T-cells, macrophage, neutrophils, and dendritic cells but not for eosinophils. We sought to define age-related changes in eosinophil function and their potential implications for asthma.
Methods: We recruited human subjects with asthma in two age groups: a younger group (20 to 40 years), and an older group (55 to 80 years). Lung function, induced sputum, and peripheral blood were obtained from each subject. Eosinophils isolated from the peripheral blood were examined for in vitro functional activities including degranulation, superoxide anion production, adhesion, and chemotaxis.
Results: Eosinophil degranulation in response to interleukin-5 stimulation was significantly decreased in the older group (p = 0.025). Eosinophil production of superoxide anions in response to phorbol myristate acetate was lower in the older group but did not achieve statistical significance (p = 0.097). Eosinophil adhesion, eosinophil chemotaxis, lung function, and the percentage of sputum eosinophils were similar in the two groups.
Conclusion: Airway eosinophilia is comparable in younger and older asthma subjects. However, there are age-related changes in peripheral blood eosinophil "effector" functions. Diseases such as asthma, in which eosinophils are thought to play a pathophysiologic role, may exhibit important clinical differences in the elderly due to age-related changes in inflammatory cell function that affect the manifestations of the disease and/or responsiveness to specific classes of medications.
Key Words: aging • asthma • eosinophil • immunosenescence
