Abstract:

Objective　To investigate the risk factors for death in elderly patients with community-acquired pneumonia, and to analyze the predictive value of ratio of regulatory T cells /T lymphocytes for their prognosis. Methods　A total of 115 patients over 90 years old who were diagnosed with community-acquired pneumonia and hospitalized in Department of Geriatrics, The Second People's Hospital of Lianyungang from January 2020 to August 2022 were selected, including 67 males and 48 females. According to the score of Mini Nutritional Assessment - Short Form (MNA-SF), they were divided into a malnutrition group (MNA-SF score ≤7 points) and a non-malnutrition group (MNA-SF score ≥8 points). Regulatory T cells, total T lymphocytes, and cytokines [interleukin (IL)-6 and IL-8] were detected within 24 hours after admission. After 28 days of follow-up, the patients were divided into a survival group and a death group according to different clinical outcomes. The risk factors for death and the predictive value of ratio of regulatory T cells /T lymphocytes for prognosis were explored. Independent sample t test, Kruskal-Wallis method, χ² test, Spearman rank correlation analysis, logistic regression analysis, receiver operating characteristic curve, and Kaplan-Meier survival analysis were used. Results　In the elderly patients with community-acquired pneumonia, 92 patients survived and 23 died, with a mortality rate of 20.00%. The Charlson Comorbidity Index (CCI), IL-6 and IL-8 in the death group were significantly higher than those in the survival group (all P<0.05), while the MNA-SF score, inflammatory-nutritional index (INI), regulatory T cells, total T lymphocytes, and ratio of regulatory T cells /T lymphocytes in the survival group were significantly higher than those in the death group (all P<0.05). According to the MNA-SF nutrition score, 64 cases were included in the malnutrition group and 51 cases were included in the non-malnutrition group, with an incidence of malnutrition of 55.65%. The mortality rate of the malnutrition group was significantly higher than that of the non-malnutrition group [34.40% (22/64) vs. 2.00% (1/51), P<0.05]. The levels of inflammatory cytokines IL-6 and IL-8 in the malnutrition group were significantly higher than those in the non-malnutrition group (both P<0.05), and the levels of regulatory T cells, total T lymphocytes, and ratio of regulatory T cells /T lymphocytes in the malnutrition group were significantly lower than those in the non-malnutrition group (all P<0.05). The MNA-SF score was positively correlated with the number of regulatory T cells and total T lymphocytes (r = 0.695 and 0.568, both P<0.05). Logistic regression analysis showed that ratio of regulatory T cells /T lymphocytes and malnutrition were the main risk factors for prognosis (OR=20.978 and 12.614, both P<0.05). The area under the curve of ratio of regulatory T cells /T lymphocytes + MNA-SF score + INI combined predicted prognosis was 0.931 (95%CI 0.885-0.976). According to whether the ratio of regulatory T cells /T lymphocytes was greater than the cut-off point of 16.21, the patients were divided into two groups. K-M curve analysis showed that there was a statistically significant difference in the 28-day survival rate between the two groups [98.41% (62/63) vs. 57.69% (30/52), χ²=30.449, P<0.001]. Conclusions　Malnutrition and imbalance of regulatory T cells are closely related to the poor outcomes of elderly patients with community-acquired pneumonia. Early nutritional intervention and immune regulation may improve the prognosis of elderly patients with community-acquired pneumonia.

Key words:

Elderly, Community acquired pneumonia, Regulatory T cells, Malnutrition, Prognosis

摘要：

目的　探讨高龄社区获得性肺炎患者死亡危险因素及调节性T细胞（Treg）/T淋巴细胞比值对患者预后的预测价值。方法　筛选2020年1月至2022年8月在连云港市第二人民医院老年医学科住院的诊断为社区获得性肺炎的年龄≥90周岁的高龄患者共115例，其中男67例，女48例。根据微型营养评定简表（Mini Nutritional Assessment - Short Form，MNA-SF）评分，分为营养不良组（MNA-SF评分≤7分）和无营养不良组（MNA-SF评分≥8分）；在入院24 h内检测Treg、总T淋巴细胞以及细胞因子白细胞介素（IL）-6、IL-8；随访28 d，根据不同临床转归，分为生存组和死亡组，探讨患者死亡的危险因素及Treg/T淋巴细胞比值对患者预后的预测价值。采用独立样本t检验、Kruskal-Wallis法、χ²检验、Spearman秩相关分析、logistic回归分析、受试者工作特征曲线、Kaplan-Meier生存分析。结果　高龄社区获得性肺炎患者中生存92例，死亡23例，病死率为20.00%。死亡组的Charlson合并症指数（CCI）、IL-6及IL-8均显著高于生存组（均P<0.05），而生存组的MNA-SF营养评分、炎症营养指数（INI）、Treg、总T淋巴细胞以及Treg/总T淋巴细胞（%）显著高于死亡组（均P<0.05）。根据MNA-SF营养评分，营养不良组纳入64例，无营养不良组51例，营养不良发生率为55.65%。营养不良组的病死率显著高于无营养不良组［34.40%（22/64）比2.00%（1/51），P<0.05］。营养不良组的炎症因子IL-6、IL-8明显高于无营养不良组（均P<0.05），营养不良组的Treg、总T淋巴细胞以及Treg/总T淋巴细胞显著低于无营养不良组（均P<0.05）。MNA-SF评分与Treg及总T淋巴细胞数目呈正相关，相关系数r分别为0.695和0.568（均P<0.05）。logistic回归分析表明，Treg/总T淋巴细胞（%）和营养不良是影响预后的主要危险因素（OR=20.978、12.614，均P<0.05）。Treg/总T淋巴细胞（%）+MNA-SF评分+INI三者联合预测预后的曲线下面积为0.931（0.885～0.976）。根据Treg/总T淋巴细胞（%）是否大于截点16.21分为两组，K-M曲线分析显示，两组28 d存活率差异有统计学意义［98.41%（62/63）比57.69%（30/52），χ²=30.449，P<0.001］。结论　营养不良及Treg失衡与高龄社区获得性肺炎患者不良结局密切相关，早期营养干预及免疫调节可改善高龄社区获得性肺炎患者预后。

关键词:

高龄, 社区获得性肺炎, 调节性T细胞, 营养不良, 预后