Department of Internal Medicine IV (Gastroenterology, Hepatology, and Infectious Diseases), Jena University Hospital, Jena, Germany.
Department of Internal Medicine I, University of Bonn, Bonn, Germany; German Center for Infection Research, University of Bonn, Bonn, Germany.
Gastroenterology. 2020 May;158(6):1745-1761. doi: 10.1053/j.gastro.2020.01.029. Epub 2020 Jan 23.
BACKGROUND & AIMS: Peritoneal macrophages (PMs) regulate inflammation and control bacterial infections in patients with decompensated cirrhosis. We aimed to characterize PMs and associate their activation with outcomes of patients with spontaneous bacterial peritonitis (SBP).
We isolated PMs from ascites samples of 66 patients with decompensated cirrhosis (19 with SBP) and analyzed them by flow cytometry, quantitative real-time polymerase chain reaction, functional analysis, and RNA microarrays. We used ascites samples of a separate cohort of 111 patients with decompensated cirrhosis (67 with SBP) and quantified the soluble form of the mannose receptor (CD206) and tumor necrosis factor by enzyme-linked immunosorbent assay (test cohort). We performed logistic regression analysis to identify factors associated with 90-day mortality. We validated our findings using data from 71 patients with cirrhosis and SBP. Data from 14 patients undergoing peritoneal dialysis for end-stage renal disease but without cirrhosis were included as controls.
We used surface levels of CD206 to identify subsets of large PMs (LPM) and small PMs (SPM), which differed in granularity and maturation markers, in ascites samples from patients with cirrhosis. LPMs vs SPMs from patients with cirrhosis had different transcriptomes; we identified more than 4000 genes that were differentially regulated in LPMs vs SPMs, including those that regulate the cycle, metabolism, self-renewal, and immune cell signaling. LPMs had an inflammatory phenotype, were less susceptible to tolerance induction, and released more tumor necrosis factor than SPMs. LPMs from patients with cirrhosis produced more inflammatory cytokines than LPMs from controls. Activation of PMs by Toll-like receptor agonists and live bacteria altered levels of CD206 on the surface of LPMs and release of soluble CD206. Analysis of serial ascites fluid from patients with SBP revealed loss of LPMs in the early phase of SBP, but levels increased after treatment. In the test and validation cohorts, patients with SBP and higher concentrations of soluble CD206 in ascites fluid (>0.53 mg/L) were less likely to survive for 90 days than those with lower levels.
Surface level of CD206 can be used to identify mature, resident, inflammatory PMs in patients with cirrhosis. Soluble CD206 is released from activated LPMs and increased concentrations in patients with cirrhosis and SBP indicate reduced odds of surviving for 90 days.
腹膜巨噬细胞（PMs）调节炎症并控制失代偿性肝硬化患者的细菌感染。我们旨在描述 PMs，并将其激活与自发性细菌性腹膜炎（SBP）患者的结局相关联。
我们从 66 例失代偿性肝硬化患者（19 例 SBP）的腹水样本中分离出 PMs，并用流式细胞术、实时定量聚合酶链反应、功能分析和 RNA 微阵列进行分析。我们使用另一组 111 例失代偿性肝硬化患者（67 例 SBP）的腹水样本，通过酶联免疫吸附试验（检测队列）定量可溶性甘露糖受体（CD206）和肿瘤坏死因子。我们进行逻辑回归分析以确定与 90 天死亡率相关的因素。我们使用 71 例肝硬化和 SBP 患者的数据验证了我们的发现。纳入 14 例因终末期肾病而行腹膜透析但无肝硬化的患者作为对照。
我们使用 CD206 的表面水平来鉴定来自肝硬化患者腹水样本中的大 PM（LPM）和小 PM（SPM）的亚群，这些亚群在颗粒度和成熟标志物上存在差异。与 SPM 相比，来自肝硬化患者的 LPM 具有不同的转录组；我们鉴定出 4000 多个在 LPM 和 SPM 中差异表达的基因，包括调节细胞周期、代谢、自我更新和免疫细胞信号的基因。LPM 具有炎症表型，对诱导耐受的敏感性较低，并且比 SPM 释放更多的肿瘤坏死因子。与对照相比，来自肝硬化患者的 LPM 产生更多的炎症细胞因子。Toll 样受体激动剂和活细菌激活 PM 后，改变了 LPM 表面的 CD206 水平和可溶性 CD206 的释放。对 SBP 患者的系列腹水液分析显示，在 SBP 的早期阶段 LPM 丢失，但治疗后水平增加。在检测和验证队列中，与较低水平的可溶性 CD206 相比，SBP 患者腹水液中可溶性 CD206 浓度较高（>0.53mg/L）的患者 90 天生存率较低。
CD206 的表面水平可用于鉴定肝硬化患者中成熟、常驻、炎症性 PM。从活化的 LPM 释放可溶性 CD206，肝硬化和 SBP 患者中浓度增加表明 90 天生存率降低。
