He cause of secondary liver damage), resulting in sepsis, multi-organ failure and impairment of liver regeneration [9,10,11,12,13]. LPS is an endotoxin derived from Gram-negative bacteria in the intestinal micro-flora. Evidently, trace amounts of LPS were measurable in serum samples from portal vein in normal healthy subjects since LPS may penetrate the intestinal mucosa. However, the majority of LPSs were cleared by liver filtration [10,14]. West et al demonstrated that about 40 ?0 of an intravenous dose of LPS was cleared up by the liver filtration in animal models [13]. In addition to the filtration, hepatic and Kupffer cell (KC) uptake in the liver with detoxification played a key role in preventing high circulating levels of LPS [9]. In CHB patients, Sozinov et al observed that high incidence of Gram-negative bacteria overgrowth leads to the over production of LPS and results in higher serum levels of LPS [14]. On the other hand, several studies in animal models suggested that delayed clearance of LPS from the circulation occurred in chronic liver diseases because of the impaired phagocytosis of KC [15,16,17]. The persistence of endotoxinemia not only 223488-57-1 manufacturer activated the liver immune cells with participating inflammatory process but also caused dysfunction of liver parenchymal cells and apoptosis [18]. Another theory on hepatic injury implied that LPS in the circulation interacted with toll like receptor 4 (TLR4) and mediated a signal transduction pathway, which included the formation of LPS-LBP-CD14secreted protein MD-2-TLR4 receptor complex [19,20,21]. The complex combined with myeloid differentiation factor 88, then phosphorylated and activated a series of cell kinases [21]. The activated kinases Hexaconazole site collectively further activated the transcription factor, mainly nuclear factor kB (NF-kB) [19,22], which resulted in increased production of pro-inflammatory cytokines, and led to hepatic necrosis [19,20,21,22,23]. Lastly, LPS may also activate hepatic 1676428 stellate cells (HSCs) to up-regulate gene expression of chemokines and adhesion molecules to induce liver injury [24,25,26]. Although the above theories on liver injury from LPS have been supported by animal models or a few in vivo studies, therelationship between the circulating LPS levels and liver disease activity or severity has not been fully explored in patients with ACHBLF. Previous published studies have focused on compensated liver disease or acute liver failure, which showed a significant correlation between elevated serum levels of 24786787 LPS and liver disease severity [11,14,27]. In animal models for ACLF, Han et al suggested that LPS circulating in the blood may reach a certain level and then triggered the secondary liver injury on top of primary chronic liver disease. However, this theory has not been fully explored in patients with ACHBLF [10]. We sought to investigate LPS levels in different disease stages of ACHBLF and the dynamic changes of LPS levels associated with the disease severity measured by clinical parameters in ACHBLF patients.Study Design and MethodsThis was a 12 week prospective, observational study with healthy controls that enrolled ACHBLF patients and healthy volunteers from a single tertiary care center, the Third Affiliated Hospital of Sun Yet-Sen University in China from October 2008 through April 2010. The study protocol and the inform consent form were both approved (IRB approval N0:2008-321) by the Ethical Committee Board of Sun Yet-Sen University. All subjects.He cause of secondary liver damage), resulting in sepsis, multi-organ failure and impairment of liver regeneration [9,10,11,12,13]. LPS is an endotoxin derived from Gram-negative bacteria in the intestinal micro-flora. Evidently, trace amounts of LPS were measurable in serum samples from portal vein in normal healthy subjects since LPS may penetrate the intestinal mucosa. However, the majority of LPSs were cleared by liver filtration [10,14]. West et al demonstrated that about 40 ?0 of an intravenous dose of LPS was cleared up by the liver filtration in animal models [13]. In addition to the filtration, hepatic and Kupffer cell (KC) uptake in the liver with detoxification played a key role in preventing high circulating levels of LPS [9]. In CHB patients, Sozinov et al observed that high incidence of Gram-negative bacteria overgrowth leads to the over production of LPS and results in higher serum levels of LPS [14]. On the other hand, several studies in animal models suggested that delayed clearance of LPS from the circulation occurred in chronic liver diseases because of the impaired phagocytosis of KC [15,16,17]. The persistence of endotoxinemia not only activated the liver immune cells with participating inflammatory process but also caused dysfunction of liver parenchymal cells and apoptosis [18]. Another theory on hepatic injury implied that LPS in the circulation interacted with toll like receptor 4 (TLR4) and mediated a signal transduction pathway, which included the formation of LPS-LBP-CD14secreted protein MD-2-TLR4 receptor complex [19,20,21]. The complex combined with myeloid differentiation factor 88, then phosphorylated and activated a series of cell kinases [21]. The activated kinases collectively further activated the transcription factor, mainly nuclear factor kB (NF-kB) [19,22], which resulted in increased production of pro-inflammatory cytokines, and led to hepatic necrosis [19,20,21,22,23]. Lastly, LPS may also activate hepatic 1676428 stellate cells (HSCs) to up-regulate gene expression of chemokines and adhesion molecules to induce liver injury [24,25,26]. Although the above theories on liver injury from LPS have been supported by animal models or a few in vivo studies, therelationship between the circulating LPS levels and liver disease activity or severity has not been fully explored in patients with ACHBLF. Previous published studies have focused on compensated liver disease or acute liver failure, which showed a significant correlation between elevated serum levels of 24786787 LPS and liver disease severity [11,14,27]. In animal models for ACLF, Han et al suggested that LPS circulating in the blood may reach a certain level and then triggered the secondary liver injury on top of primary chronic liver disease. However, this theory has not been fully explored in patients with ACHBLF [10]. We sought to investigate LPS levels in different disease stages of ACHBLF and the dynamic changes of LPS levels associated with the disease severity measured by clinical parameters in ACHBLF patients.Study Design and MethodsThis was a 12 week prospective, observational study with healthy controls that enrolled ACHBLF patients and healthy volunteers from a single tertiary care center, the Third Affiliated Hospital of Sun Yet-Sen University in China from October 2008 through April 2010. The study protocol and the inform consent form were both approved (IRB approval N0:2008-321) by the Ethical Committee Board of Sun Yet-Sen University. All subjects.
