From the University of Michigan, College of Pharmacy, Ann Arbor, Michigan.
University of Michigan, Division of Nephrology, Ann Arbor, Michigan.
ASAIO J. 2020 Aug;66(8):960-965. doi: 10.1097/MAT.0000000000001091.
Tunneled central venous catheters (TCVCs) are colonized by Gram-positive organisms and form biofilm. Lipoteichoic acid (LTA) is a Gram-positive cell wall component that can be measured in serum. The purpose of this pilot study was to characterize LTA concentrations in hemodialysis (HD) patients with TCVCs compared to other access types and to evaluate biofilm morphology and microbiology in TCVCs removed by clinical decision. The study enrolled patients with TCVCs (18), grafts (19), and fistulas (18). Blood samples were collected before HD, at 30 minutes, 2 hours, and end of HD. Catheters removed by clinical decision were evaluated by scanning electron microscopy (SEM) for biofilm morphology, and portions of the catheter were cultured. LTA was detectable in all samples and concentrations increased significantly in all access types during HD (p < 0.05 for all comparisons). Patients with TCVCs that had a >30% increase in LTA concentration from baseline also had the greatest rate of increase (slope) compared to grafts and fistulas (p = 0.03 and p = 0.04, respectively). Catheters removed by clinical decision (n = 7) and examined by SEM had deposition of fibrin. Cultures revealed polymicrobial colonization. TCVCs had the highest rate of increase of LTA during HD. Further studies to determine the source of LTA in patients with AVG and AVF are warranted.
经皮隧道式中心静脉导管（TCVCs）被革兰氏阳性菌定植并形成生物膜。脂磷壁酸（LTA）是革兰氏阳性菌细胞壁的组成部分，可以在血清中测量。本初步研究的目的是比较 TCVC 患者与其他通路类型的 LTA 浓度，并评估临床决策下移除的 TCVC 中的生物膜形态和微生物学。该研究纳入了 TCVC（18 例）、移植物（19 例）和瘘管（18 例）患者。在 HD 前、HD 后 30 分钟、2 小时和结束时采集血样。通过扫描电子显微镜（SEM）评估临床决策下移除的导管的生物膜形态，并对导管的部分部位进行培养。所有样本均检测到 LTA，所有通路类型在 HD 期间 LTA 浓度均显著增加（所有比较均 p < 0.05）。与移植物和瘘管相比，TCVC 患者的 LTA 浓度从基线增加>30%的患者也有最大的增加率（斜率）（分别为 p = 0.03 和 p = 0.04）。通过临床决策移除的导管（n = 7）并通过 SEM 检查，发现有纤维蛋白沉积。培养显示多种微生物定植。TCVC 在 HD 期间 LTA 的增加率最高。需要进一步研究以确定 AVG 和 AVF 患者中 LTA 的来源。
