An activated plasma contact system is an abnormality observed in many Alzheimer’s disease (AD) patients. Since mild cognitive impairment (MCI) patients often develop AD, we analyzed the status of contact system activation in MCI patients. We found that kallikrein activity, high molecular weight kininogen cleavage, and bradykinin levels— measures of contact system activation— were significantly elevated in MCI patient plasma compared to plasma from age- and education-matched healthy individuals. Changes were more pronounced in MCI patients with impaired short-term recall memory, indicating the possible role of the contact system in early cognitive changes.

中文翻译：

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短期记忆受损的轻度认知障碍患者的接触系统激活增加。

激活的血浆接触系统是在许多阿尔茨海默病 (AD) 患者中观察到的异常。由于轻度认知障碍 (MCI) 患者经常发生 AD，我们分析了 MCI 患者的接触系统激活状态。我们发现，与年龄和教育相匹配的健康个体的血浆相比，MCI 患者血浆中的激肽释放酶活性、高分子量激肽原裂解和缓激肽水平（接触系统激活的度量）显着升高。短期回忆记忆受损的 MCI 患者的变化更为明显，表明接触系​​统可能在早期认知变化中发挥作用。