Background and aims

Increasing evidence suggests that inflammation plays an important role in brain aging and neurodegeneration. Pathological studies demonstrate the presence of C-reactive protein (CRP) in the senile plaques and neurofibrillary tangles in Alzheimer's disease (AD) brain tissue suggesting that CRP may play a role in its neuropathological processes. Some findings suggest that midlife elevations of serum CRP are a risk factor for AD. However, others found lower CRP levels in mild or moderate AD than in controls, suggesting that CRP levels could be different in different stages of disease. We aimed to assess the role of CRP as a predictor of Mild cognitive impairment (MCI) conversion into AD dementia.

Methods

We retrospectively reviewed the cohort of MCI patients followed at the Dementia Clinic, Neurology Department of University Hospital of Coimbra. We collected demographical, neuropsychological, genetic and laboratorial variables (including serum CRP measurements at the time of baseline laboratory tests). A Cox regression model was performed adjusted for the collected variables preconsidered to be predictors of dementia and the variable being studied (CRP) to assess for independent predictors of conversion.

Results

We included 130 patients, 58.5% female, with a mean age of onset of 65.5 ± 9.1 years and age at first assessment of 69.3 ± 8.5 years. The mean CRP was 0.33 ± 0.58 mg/dl. At follow-up (mean, 36.9 ± 27.0 months) 42.3% of MCI patients converted to dementia. Lower CSF Aβ42 (HR = 0.999, 95%CI = [0.997, 1.000], p = 0.015), lower MMSE score (HR = 0.864, 95%CI = [0.510, 1.595], p = 0.008) and lower CRP quartile (HR = 0.597, 95%CI = [0.435, 0.819], p = 0.001) were independent predictors of conversion.

Conclusion

CRP may add information of risk of conversion in MCI patients. Patients with lower CRP levels appear to have a more rapid conversion to AD dementia.

中文翻译：

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C-反应蛋白作为轻度认知障碍转化为阿尔茨海默病痴呆的预测因子。

背景和目标

越来越多的证据表明，炎症在大脑衰老和神经退行性变中起着重要作用。病理学研究表明，老年斑和阿尔茨海默病 (AD) 脑组织中的神经原纤维缠结中存在 C 反应蛋白 (CRP)，这表明 CRP 可能在其神经病理学过程中发挥作用。一些研究结果表明，中年时血清 CRP 升高是 AD 的危险因素。然而，其他人发现轻度或中度 AD 患者的 CRP 水平低于对照组，这表明 CRP 水平在疾病的不同阶段可能不同。我们旨在评估 CRP 作为轻度认知障碍 (MCI) 转变为 AD 痴呆的预测因子的作用。

方法

我们回顾性地回顾了在科英布拉大学医院神经内科痴呆诊所随访的 MCI 患者队列。我们收集了人口统计学、神经心理学、遗传和实验室变量（包括基线实验室测试时的血清 CRP 测量值）。对预先认为是痴呆症预测因子的收集变量和正在研究的变量 (CRP) 进行调整，以评估转换的独立预测因子，执行 Cox 回归模型。

结果

我们纳入了 130 名患者，其中 58.5% 为女性，平均发病年龄为 65.5 ± 9.1 岁，首次评估年龄为 69.3 ± 8.5 岁。平均 CRP 为 0.33 ± 0.58 mg/dl。随访时（平均 36.9 ± 27.0 个月），42.3% 的 MCI 患者转为痴呆。较低的 CSF Aβ42 (HR = 0.999, 95%CI = [0.997, 1.000], p = 0.015)，较低的 MMSE 评分 (HR = 0.864, 95%CI = [0.510, 1.595], p = 0.008) 和较低的 CRP 四分位数 ( HR = 0.597, 95%CI = [0.435, 0.819], p = 0.001) 是转化的独立预测因子。

结论

CRP 可能会增加 MCI 患者转化风险的信息。CRP 水平较低的患者似乎更快速地转化为 AD 痴呆。