Hepatology : official journal of the American Association for the Study of Liver Diseases
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Remote ischemic preconditioning (RIPC), the repetitive transient mechanical obstruction of vessels at a limb remote to the operative site, is a novel strategy to mitigate distant organ injury associated with surgery. In the clinic, RIPC has demonstrated efficacy in protecting various organs against ischemia reperfusion (IR), but a common mechanism underlying the systemic protection has not been identified. Here, we reasoned that protection may rely on adaptive physiological responses toward local stress, as is incurred through RIPC. Standardized mouse models of partial hepatic IR and of RIPC to the femoral vascular bundle were applied. The roles of platelets, peripheral serotonin, and circulating vascular endothelial growth factor (Vegf) were studied in thrombocytopenic mice, Tph1(-) (/) (-) mice, and through neutralizing antibodies, respectively. Models of interleukin-10 (Il10) and matrix metalloproteinase 8 (Mmp8) deficiency were used to assess downstream effectors of organ protection. The protection against hepatic IR through RIPC was dependent on platelet-derived serotonin. Downstream of serotonin, systemic protection was spread through up-regulation of circulating Vegf. Both RIPC and serotonin-Vegf induced differential gene expression in target organs, with Il10 and Mmp8 displaying consistent up-regulation across all organs investigated. Concerted inhibition of both molecules abolished the protective effects of RIPC. RIPC was able to mitigate pancreatitis, indicating that it can protect beyond ischemic insults. ⋯ We have identified a platelet-serotonin-Vegf-Il10/Mmp8 axis that mediates the protective effects of RIPC. The systemic action, the conservation of RIPC effects among mice and humans, and the protection beyond ischemic insults suggest that the platelet-dependent axis has evolved as a preemptive response to local stress, priming the body against impending harm.
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Tumor cells express vascular endothelial growth factor (VEGF) that can activate VEGF receptors (VEGFRs) on or within tumor cells to promote growth in an angiogenesis-independent fashion; however, this autocrine VEGF pathway has not been reported in hepatocellular carcinoma (HCC). Sorafenib, an angiogenic inhibitor, is the only drug approved for use in advanced HCC patients. Yet the treatment efficacy is diverse and the mechanism behind it remains undetermined. Our aims were to study the molecular mechanisms underlying autocrine VEGF signaling in HCC cells and evaluate the critical role of autocrine VEGF signaling on sorafenib treatment efficacy. By immunohistochemistry, we found robust nuclear and cytoplasmic staining for active, phosphorylated VEGF receptor 1 (pVEGFR1) and phosphorylated VEGF receptor 2 (pVEGFR2), and by western blotting we found that membrane VEGFR1 and VEGFR2 increased in HCC tissues. We showed that autocrine VEGF promoted phosphorylation of VEGFR1 and VEGFR2 and internalization of pVEGFR2 in HCC cells, which was both pro-proliferative through a protein lipase C-extracellular kinase pathway and self-sustaining through increasing VEGF, VEGFR1, and VEGFR2 mRNA expressions. In high VEGFR1/2-expressing HepG2 cells, sorafenib treatment inhibited cell proliferation, reduced VEGFR2 mRNA expression in vitro, and delayed xenograft tumor growth in vivo. These results were not found in low VEGFR1/2-expressing Hep3B cells. In an advanced HCC population on sorafenib treatment for postoperative recurrence, we found that the absence of VEGFR1 or VEGFR2 expression in resected tumor tissues before sorafenib treatment was associated with poorer overall survival. ⋯ Autocrine VEGF signaling directly promotes HCC cell proliferation and affects the sorafenib treatment outcome in vitro and in vivo, which may enable better stratification for clinical treatment decisions.
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Review Meta Analysis
Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis C.
The cost-effectiveness of noninvasive tests (NITs) as alternatives to liver biopsy is unknown. We compared the cost-effectiveness of using NITs to inform treatment decisions in adult patients with chronic hepatitis C (CHC). We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes (quality-adjusted life-years; QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four treatment strategies: testing with NITs and treating patients with fibrosis stage≥F2; testing with liver biopsy and treating patients with ≥F2; treat none; and treat all irrespective of fibrosis. We compared all NITs and tested the cost-effectiveness using current triple therapy with boceprevir or telaprevir, but also modeled new, more-potent antivirals. Treating all patients without any previous NIT was the most effective strategy and had an incremental cost-effectiveness ratio (ICER) of £9,204 per additional QALY gained. The exploratory analysis of currently licensed sofosbuvir treatment regimens found that treat all was cost-effective, compared to using an NIT to decide on treatment, with an ICER of £16,028 per QALY gained. The exploratory analysis to assess the possible effect on results of new treatments, found that if SVR rates increased to >90% for genotypes 1-4, the incremental treatment cost threshold for the "treat all" strategy to remain the most cost-effective strategy would be £37,500. Above this threshold, the most cost-effective option would be noninvasive testing with magnetic resonance elastography (ICER=£9,189). ⋯ Treating all adult patients with CHC, irrespective of fibrosis stage, is the most cost-effective strategy with currently available drugs in developed countries.
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Randomized Controlled Trial Multicenter Study Comparative Study
Lack of difference among terlipressin, somatostatin, and octreotide in the control of acute gastroesophageal variceal hemorrhage.
Vasoactive drugs are recommended to be started as soon as possible in suspected variceal bleeding, even before diagnostic endoscopy. However, it is still unclear whether the therapeutic efficacies of the various vasoactive drugs used are comparable. The aim of this prospective, multicenter, randomized, noninferiority trial was to characterize the effects of terlipressin, somatostatin, and octreotide when they are initiated before endoscopic treatment in patients with acute variceal bleeding. Patients with liver cirrhosis and significant upper gastrointestinal bleeding were randomly assigned to receive early administration of terlipressin, somatostatin, or octreotide, followed by endoscopic treatment. Patients with nonvariceal bleeding were excluded after endoscopy. The primary endpoint was 5-day treatment success, defined as control of bleeding without rescue treatment, rebleeding, or mortality, with a noninferiority margin of 0.1. In total, 780 patients with variceal bleeding were enrolled: 261 in the terlipressin group; 259 in the somatostatin group; and 260 in the octreotide group. At the time of initial endoscopy, active bleeding was noted in 43.7%, 44.4%, and 43.5% of these patients, respectively (P=0.748), and treatment success was achieved by day 5 in 86.2%, 83.4%, and 83.8% (P=0.636), with similar rates of control of bleeding without rescue treatment (89.7%, 87.6%, and 88.1%; P=0.752), rebleeding (3.4%, 4.8%, and 4.4%; P=0.739), or mortality (8.0%, 8.9%, and 8.8%; P=0.929). The absolute values of the lower bound of confidence intervals for terlipressin versus somatostatin, terlilpressin versus octreotide, and octreotide versus somatostatin were 0.095, 0.090, and 0.065, respectively. ⋯ Hemostatic effects and safety did not differ significantly between terlipressin, somatostatin, and octreotide as adjuvants to endoscopic treatment in patients with acute gastroesophageal variceal bleeding.