长期卧床高龄患者医院内感染前后血浆白蛋白水平及细胞免疫功能的变化

摘要

目的探讨长期卧床高龄患者医院内感染前后血浆白蛋白（ALB）水平及细胞免疫功能的变化及关系。方法选择2009年1月至2012年12月在广州军区广州总医院住院的长期卧床且住院期间发生院内感染的高龄患者共78例，按感染前、感染持续≥5d、感染持续≥10d以及感染进一步发展成严重脓毒症或脓毒性休克4个时期分为B组（n＝78）、C组（n＝52）、D组（n＝33）、E组（n＝25）；随机选择同期住院非长期卧床、无感染的高龄患者作为对照组（A组， n＝40）。分别检测不同时期患者血浆ALB水平、细胞免疫功能[包括外周血单核细胞表面人白细胞抗原-DR（HLA-DR）及T细胞亚群]；统计处理时进一步将感染前患者（B组）按血浆ALB水平分为ALB正常组（B1组，n＝16）和ALB偏低组（B2组，n＝62）。结果与A组相比，B组血浆ALB显著降低（P＝0.000）；与A组及B组相比，C、D、E三组血浆ALB均显著降低（P＝0.000）。与A组相比，B1组细胞免疫功能差异无统计学意义（P＞0.05），B2组HLA-DR的表达、CD3+T细胞绝对值以及CD4/CD8比值均显著降低（P＝0.000），CD8+T细胞占CD3+T细胞的百分数（CD8/CD3）显著升高（P＝0.000），CD4+T细胞占CD3+T细胞的百分数（CD4/CD3）差异无统计学意义（P＞0.05）。与A组及B组相比， C、D、E三组HLA-DR的表达、CD3+T细胞的绝对值、CD4/CD3以及CD4/CD8比值均显著减低（P＝0.000），CD8/CD3显著升高（P＝0.000）；而且HLA-DR、CD3+T细胞绝对值、CD4/CD3、CD8/CD3、CD4/CD8比值与血浆ALB水平的相关系数分别为r1＝0.791，r2＝0.638，r3＝0.534，r4＝-0.575，r5＝0.580（均P＝0.000）。结论长期卧床高龄患者医院内感染前血浆ALB已显著减低，感染后血浆ALB水平进一步下降，血浆ALB水平降低的患者其细胞免疫功能也下降，而且患者感染前后细胞免疫功能的下降与血浆ALB水平的降低密切相关。%Objective To investigate the changes of plasma albumin (ALB) level and cellular immune function, and their relationship in elderly bed-ridden patients before and after nosocomial infection. Methods Seventy-eight elderly bed-ridden patients getting nosocomial infection during hospitalization in our department from January 2009 to December 2012 were enrolled in this study. The clinical data of the patients before getting nosocomial infection (group B, n=78), suffering from infection for ≥5d (group C, n=52) and for ≥10d (group D, n=33), and having severe sepsis/septic shock (group E, n=25) were collected and retrospectively analyzed. Another 40 elderly patients hospitalized in the same period without bed-ridden or infection served as control (group A). Plasma ALB level and cellular immune function, including peripheral blood mononuclear cell surface human leukocyte antigen-DR (HLA-DR) and T cell subsets, were compared among the patients at different periods. The group B were further assigned into group B1 (normal ALB level, n=16) and group B2 (lower ALB level, n=62) according to their ALB level. Results Plasma ALB level was significantly lower in group B than in group A (P=0.000), and significantly lower in group C, D, and E than in group A and B (P=0.000). Cellular immune function was similar in group B1 and group A. Patients of group B2 had significantly lower expression of HLA-DR, decreased absolute number of CD3+T cells and CD4/CD8 ratio (P=0.000), significantly increased percentage of CD8+T cells among CD3+T cells (CD8/CD3; P=0.000), and unchanged percentage of CD4+T cells among CD3+T cells(CD4/CD3; P>0.05). Compared with those of group A and B, HLA-DR expression, absolute number of CD3+ T cells, CD4/CD8 ratio, and CD4/CD3 ratio were significantly lower in group C, D and E (P=0.000), and CD8/CD3 was significantly higher (P=0.000). The changes of HLA-DR, absolute number of CD3+T cells, and CD4/CD3, CD8/CD3 and CD4/CD8 ratios were all correlated with plasma ALB level (r1=0.791, r2=0.638, r3=0.534, r4=-0.575, r5=0.580; P=0.000). Conclusion Plasma ALB level has been significantly reduced in elderly bed-ridden patients before nosocomial infection, and the level declines steadily thereafter the infection. The decreased cellular immune function before and after nosocomial infection is closely associated with the declined plasma ALB levels.