There is consistent evidence that immune response declines with aging, with wide inter-individual variability and a still unclear relationship with the development of frailty. To address this question we assessed the role of immune resilience (capacity to restore immune functions), operationalized as the neutrophil-to-lymphocytes ratio (NL-ratio) and monocytes-to-lymphocytes ratio (ML-ratio), in the pathway that from robust status shifts to pre-frailty and frailty, and finally to death. The InCHIANTI study enrolled representative samples from the registry lists of two towns in Tuscany, Italy. Baseline data were collected in 1998, with follow up visits every three years. The 1453 participants enrolled were assessed and followed for lifestyle, clinical condition, physical performance, clinical and physiological measures. For the purpose of this analysis we used only 1022 subjects aged 65 or older at baseline. Participants in the three highest deciles of distribution for NL-ratio (>2.44) were more likely to experience a transition from robust to pre-frail, and to overt frailty status. Moreover, NL-ratio (tenth decile >3.53) and ML-ratio (tenth decile>2.02) were both predictors of mortality. These results were independent from chronological age, sex, comorbidities, and chronic low-grade inflammation assessed by high sensitivity C-reactive protein measurement. The two leucocytes-derived ratios, NL-ratio and ML-ratio, represent markers of immune resilience and predict changes in physical resilience and mortality. These biomarkers are inexpensive since based on data routinely collected in clinical practice, and can be used to assess the risk of frailty progression and mortality.

中文翻译：

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缺乏免疫弹性会对身体弹性产生负面影响。InCHIANTI 后续研究的结果

有一致的证据表明，免疫反应随着年龄的增长而下降，个体间存在很大的差异，并且与虚弱发展的关系仍不清楚。为了解决这个问题，我们评估了免疫弹性（恢复免疫功能的能力）的作用，可操作为中性粒细胞与淋巴细胞比率（NL-比率）和单核细胞与淋巴细胞比率（ML-比率），在以下途径中：从强健状态转变为衰弱前期和衰弱状态，最后到死亡。InCHIANTI 研究从意大利托斯卡纳两个城镇的登记名单中招募了代表性样本。基线数据于 1998 年收集，每三年进行一次随访。对 1453 名参与者的生活方式、临床状况、身体表现、临床和生理指标进行了评估和跟踪。为了进行本次分析，我们仅使用了 1022 名基线年龄为 65 岁或以上的受试者。NL 比率分布的三个最高十分位（>2.44）的参与者更有可能经历从强健到虚弱前状态以及到明显虚弱状态的转变。此外，NL比率(十分之一＞3.53)和ML比率(十分之一＞2.02)都是死亡率的预测因子。这些结果独立于实际年龄、性别、合并症和通过高灵敏度 C 反应蛋白测量评估的慢性低度炎症。两个白细胞衍生比率（NL 比率和 ML 比率）代表免疫恢复力的标志，并预测身体恢复力和死亡率的变化。这些生物标志物价格低廉，因为它们基于临床实践中常规收集的数据，可用于评估衰弱进展和死亡的风险。