Barton Pai Amy, Garba Adinoyi, Neumann Paul, Prokopienko Alexander J, Costello Gabrielle, Dean Michael C, Narsipur Sriram
College of Pharmacy, University of Michigan, Ann Arbor, MI, United States.
D'Youville College School of Pharmacy, Buffalo, NY, United States.
Front Med (Lausanne). 2018 Nov 5;5:308. doi: 10.3389/fmed.2018.00308. eCollection 2018.
Hemodialysis patients with central venous catheters (CVCs) have chronic systemic inflammation, the source of which may be related to intraluminal bacterial biofilm. There is currently no non-invasive method to adequately evaluate intraluminal biofilm. Lipoteichoic acid (LTA) is a Gram-positive bacterial cell wall component that is spontaneously shed. The purpose of this study was to determine whether LTA could be quantified in biological samples and to evaluate potential relationships to markers of inflammation. Heparin-locked catheter aspirate was drawn from both the arterial and venous ports of each CVC prior to dialysis initiation. Venous blood from the dialysis circuit was collected 30 min after dialysis initiation. LTA was quantified in aspirate and plasma. Key markers of inflammation (interleukin-6, and hepcidin) and endothelial dysfunction (soluble vascular endothelial cadherin) were also determined in plasma samples. Catheter aspirate and systemic blood samples were obtained from 40 hemodialysis patients. The median (range) duration of catheter use was 130 (20-1635) days. Unexpectedly, median (range) plasma LTA concentrations (ng/mL) were significantly higher than catheter aspirate LTA concentrations [3.93 (0.25-15) vs. 2.38 (0.1-8.1), respectively, = 0.01] in the majority (70%) of patients. Area under the receiver operator characteristic (ROC) curve showed good potential prognostic value of catheter aspirate LTA predicting systemic LTA concentrations with an area under the curve of 0.815 (95% CI, 0.68-0.95). A significant correlation was found between LTA and serum ferritin ( = 0.32, = 0.04), however, there were no significant correlations between LTA and the other inflammation biomarkers assessed. LTA is quantifiable in aspirate and plasma of hemodialysis patients with CVCs and warrants further investigation to determine potential clinical application to intraluminal biofilm evaluation.
患有中心静脉导管（CVC）的血液透析患者存在慢性全身炎症，其来源可能与管腔内细菌生物膜有关。目前尚无充分评估管腔内生物膜的非侵入性方法。脂磷壁酸（LTA）是革兰氏阳性菌细胞壁的一种会自然脱落的成分。本研究的目的是确定LTA是否可在生物样本中进行定量，并评估其与炎症标志物的潜在关系。在透析开始前，从每个CVC的动脉端和静脉端抽取肝素封管液。透析开始30分钟后，从透析回路采集静脉血。对封管液和血浆中的LTA进行定量。还在血浆样本中测定炎症的关键标志物（白细胞介素-6和铁调素）以及内皮功能障碍（可溶性血管内皮钙黏蛋白）。从40例血液透析患者中获取封管液和全身血样本。导管使用的中位（范围）时长为130（20 - 1635）天。出乎意料的是，在大多数（70%）患者中，血浆LTA浓度中位数（范围）（ng/mL）显著高于封管液LTA浓度[分别为3.93（0.25 - 15）和2.38（0.1 - 8.1），P = 0.01]。受试者操作特征（ROC）曲线下面积显示，封管液LTA预测全身LTA浓度具有良好的潜在预后价值，曲线下面积为0.815（95%CI，0.68 - 0.95）。发现LTA与血清铁蛋白之间存在显著相关性（r = 0.32，P = 0.04），然而，LTA与所评估的其他炎症生物标志物之间无显著相关性。LTA可在患有CVC的血液透析患者的封管液和血浆中进行定量，值得进一步研究以确定其在管腔内生物膜评估中的潜在临床应用。
