Liver Transplantation Using Hepatitis C Virus-Viremic Donors Into Hepatitis C Virus-Aviremic Recipients as Standard of Care.

Liver transplantation (LT) using allografts from hepatitis C virus (HCV)-viremic/nucleic acid testing-positive donors' (DNAT+) organs into HCV-aviremic recipients (rHCV-) has been limited owing to nearly universal HCV transmission and concerns regarding availability, safety, and efficacy post-LT with direct-acting antiviral (DAA) therapy. We report our experience of LT using DNAT+ organs into rHCV- as a routine standard of care. Following verification of DAA access, absence of critical drug-drug interactions (DDIs) with DAAs, and informed consent, allocated DNAT+ organs were offered to patients on the waiting list for LT irrespective of recipient HCV status. Between June 2018 and December 2019, 292/339 rHCV- received an LT. Forty-seven patients were excluded from analysis because of recipient HCV viremia, refusal to receive DNAT+ organs, or inability to receive DAA therapy post-LT. Of these 292 patients, 61 rHCV- received DNAT+ livers (study group), and 231 rHCV- received DNAT- (aviremic donors [nuclear acid test-negative donors]) livers (control group). Recipient and donor characteristics as well as 1-year post-LT patient and graft survival were similar between groups. In the study group, 4 patients died, and 1 patient required retransplantation within the first year post-LT (all unrelated to HCV); 56 patients received DAA therapy, with a median time from LT to the start of DAA treatment of 66.9 days (interquartile range [IQR], 36-68.5), and 51 patients completed DAA treatment, all achieving sustained virologic response for 12 or more weeks (SVR-12) (1 patient required retreatment owing to relapse following initial DAA therapy). No patients had evidence of fibrosing cholestatic hepatitis or extrahepatic manifestations of HCV. This report indicates that transplantation of DNAT+ livers into rHCV- and subsequent DAA therapy is associated with clinical outcomes comparable to those achieved with DNAT- allografts.

Predictive model and risk factors associated with a revised definition of early allograft dysfunction in liver transplant recipients.

INTRODUCTION: Early allograft dysfunction (EAD) is a well-defined clinical syndrome that reflects overall graft function within the first week after transplant. The aim of this study was to further refine the definition for EAD. METHOD: In this study, 1124 patients were included for analysis. Logistic regression was performed to identify markers of liver injury associated with 6-month patient and graft failure. RESULTS: Recursive partitioning identified cut-points for ALT/AST > 3000/6000 IU/dL observed within first week, with bilirubin ≥ 10 mg/dL and INR ≥ 1.6 on postoperative day 7 for the revised EAD model. The incidence of updated EAD was 15% (164/1124). Multivariable analysis identified eight risk factors associated with EAD: % macrosteatosis, donor location, donor weight, nonheart beating donors, type of organ transplanted, recipient-associated hepatocellular carcinoma, severity of postreperfusion syndrome, and the amount of transfused fresh frozen plasma. In the presence of EAD, the incidence of post-transplant renal replacement therapy and dialysis dependence increases. There was a significant association of the presence of EAD with 6-month mortality (12% vs 3%) and 6-month graft failure (8% vs 1%). CONCLUSION: Higher AST/ALT level needed as cutoff in comparison with the old EAD definition.

Simulated aeromedical evacuation does not affect systemic inflammation or organ injury in a murine model of hemorrhagic shock.

Hemorrhagic shock is a primary injury amongst combat casualties. Aeromedical evacuation (AE) of casualties exposes patients to a hypobaric, hypoxic environment. The effect of this environment on the host response to hemorrhagic shock is unknown. In the present study, we sought to determine the effect of simulated AE on systemic inflammation and organ injury using a murine model of hemorrhagic shock. Mice underwent femoral artery cannulation and were hemorrhaged for 60 minutes. Mice were then resuscitated with a 1:1 ratio of plasma:packed red blood cells. At 1 or 24 hours after resuscitation, mice were exposed to a 5-hour simulated AE or remained at ground level (control). Serum was analyzed for cytokine concentrations and organs were assessed for neutrophil accumulation and vascular permeability. Mice in the simulated AE groups demonstrated reduced arterial oxygen saturation compared to ground controls. Serum cytokine concentrations, neutrophil recruitment, and vascular permeability in the lung, ileum, and colon in the simulated AE groups were not different from the ground controls. Our results demonstrate that mice exposed to simulated AE following hemorrhagic shock do not exhibit worsened systemic inflammation or organ injury compared to controls. The data suggest that AE has no adverse effect on isolated hemorrhagic shock.

Three-Dimensional Visualization With Virtual Reality Facilitates Complex Live Donor Renal Transplant.

Background: Living donor renal transplant involves highly technical operations in both a healthy donor and a recipient with end-stage kidney disease. Contrast-enhanced computed tomography angiography (CTA) is used to assess critical donor anatomy, but its interpretation becomes increasingly difficult as renal anatomy becomes more complex. Case Report: A related donor was denied because of prohibitive anatomy seen on the pretransplant evaluation CTA. As the donor was highly motivated to donate, CTA DICOM images were segmented to create a 3-dimensional (3D) model that could be evaluated in an immersive and stereoscopic virtual reality (VR) environment. The donor's anatomy was found to be acceptable, and he was approved. Conclusion: In live donor nephrectomy candidates, 3D reconstruction and VR visualization can be used to facilitate appreciation of complex anatomy.

Hemorrhagic shock induces a proinflammatory milieu in the gut lumen.

BACKGROUND: Intestinal injury is a consequence of hemorrhagic shock and resuscitation. The intestinal mucosa has been shown to respond to ischemia/reperfusion injury with production of inflammatory mediators. Previous work in our laboratory indicates that intestinal epithelial cells secrete proinflammatory cytokines in the direction of both the lamina propria and intestinal lumen. The ability of the intestinal mucosa to transmit inflammatory signals into the gut lumen after hemorrhagic shock is unknown. We hypothesized that hemorrhagic shock results in secretion of proinflammatory cytokines into the gut lumen. METHODS: Male C57/Bl6 mice underwent femoral artery cannulation and hemorrhage to a systolic blood pressure of 20 mmHg for 1 h, then resuscitation with lactated Ringer's (LR) solution. Sham animals were cannulated only. Mice were decannulated and sacrificed at intervals. Stool and succus were removed from intestinal segments, weighed, and placed into buffer solution. Specimens were analyzed via enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with sham-injured mice, hemorrhagic shock resulted in increased intestinal luminal cytokines. At 3 h after injury, elevated levels of IL-6 were found in the cecal stool. At 6 h after injury, TNFα, IL-6, and MIP-2 were significantly elevated in the cecal stool, and IL-6 and MIP-2 were significantly elevated in the distal colonic stool. CONCLUSIONS: Hemorrhagic shock results in secretion of proinflammatory cytokines into the intestinal lumen. These findings suggest that the intestinal mucosa may transmit and receive signals in a paracrine fashion via the gut lumen.

Proinflammatory chemokines in the intestinal lumen contribute to intestinal dysfunction during endotoxemia.

Intestinal failure is common in patients with septic shock, with dysfunction of the gut often manifesting as both a cause and consequence of their critical illness. Most studies investigating the pathogenesis of intestinal failure focus on the systemic aspect, although few data examine the inflammatory signaling in the intestinal lumen. Having previously demonstrated apical/luminal chemokine secretion in an in vitro model of intestinal inflammation, we hypothesized that endotoxemia would induce secretion of proinflammatory chemokines into the intestinal lumen. In addition, we examined the contribution of these mediators to intestinal dysmotility. C57/BL6 male mice were injected intraperitoneally with LPS. Serum, intestinal tissue, and intestinal luminal contents were harvested for cytokine analysis. For intestinal motility studies, a transit assay was performed after oral gavage of chemokines. Caco-2 cells grown on Transwell culture inserts were used to examine the role of the intestinal epithelium in chemokine secretion. Monocyte chemoattractant protein 1 (MCP-1/CCL2) and macrophage-derived chemokine (MDC/CCL22) were secreted into the lumen of multiple segments of the gut during endotoxemia in mice. In vitro work showed that the intestinal epithelium participates in monocyte chemoattractant protein 1 and MDC secretion and expresses the CCR2 and CCR4 receptors for these chemokines. Intestinal transit studies show that oral gavage of MDC results in impaired gut motility. This study demonstrates that the intestinal lumen is an active compartment in the gut's inflammatory response. Proinflammatory chemokines are secreted into the intestinal lumen during endotoxemia. These intraluminal chemokines contribute to intestinal dysmotility, complicating intestinal failure.

Resuscitation with washed aged packed red blood cell units decreases the proinflammatory response in mice after hemorrhage.

BACKGROUND: Resuscitation with blood products instead of crystalloid in the treatment of hemorrhagic shock has been associated with improved outcomes in trauma patients requiring massive transfusions and transfusion of fresh products results in reduced morbidity and mortality compared with aged blood. Processes to eliminate harmful components of aged blood are under investigation. We hypothesized that washing blood would reduce levels of proinflammatory mediators in stored units, and resuscitation with washed units would attenuate the proinflammatory response in mice after hemorrhagic shock. METHODS: Mice underwent pressure-controlled hemorrhage and resuscitation with fresh packed red blood cells (pRBCs) or 15-day-old washed or unwashed pRBCs. Cytokine concentrations in donor samples and recipient serum were measured. In addition, cytokine concentrations were measured in 15-day-old units that underwent three interval washes versus one poststorage wash. RESULTS: Blood stored for 15 days demonstrated increased levels of interleukin 1α, keratinocyte chemoattractant, macrophage inflammatory protein 1α, and macrophage inflammatory protein 2 compared with fresh units. Washing 15-day-old pRBCs reduced concentrations of these cytokines. Cytokine levels in stored units that underwent multiple washes versus a single wash were not different. Mice resuscitated with 15-day-old unwashed pRBCs had increased levels of serum cytokines compared with mice resuscitated with fresh and 15-day-old washed pRBCs. CONCLUSION: Aged pRBC units have elevated levels of proinflammatory cytokines compared with fresh units, and washing aged units after storage reduces cytokine concentrations. Resuscitation with washed units blunts the proinflammatory response in mice after hemorrhage. Washing aged pRBCs may improve the safety profile of aged units and may result in improved outcomes in subjects after hemorrhagic shock and resuscitation.

Supplemental oxygen attenuates the increase in wound bacterial growth during simulated aeromedical evacuation in goats.

BACKGROUND: Bacterial growth in soft tissue and open fractures is a known risk factor for tissue loss and complications in contaminated musculoskeletal wounds. Current care for battlefield casualties with soft tissue and musculoskeletal wounds includes tactical and strategic aeromedical evacuation (AE). This exposes patients to a hypobaric, hypoxic environment. In this study, we sought to determine whether exposure to AE alters bacterial growth in contaminated complex musculoskeletal wounds and whether supplemental oxygen had any effect on wound infections during simulated AE. METHODS: A caprine model of a contaminated complex musculoskeletal wound was used. Complex musculoskeletal wounds were created and inoculated with bioluminescent Pseudomonas aeruginosa. Goats were divided into three experimental groups: ground control, simulated AE, and simulated AE with supplemental oxygen. Simulated AE was induced in a hypobaric chamber pressurized to 8,800 feet for 7 hours. Bacterial luminescence was measured using a photon counting camera at three time points: preflight (20 hours postsurgery), postflight (7 hours from preflight and 27 hours postsurgery), and necropsy (24 hours from preflight and 44 hours postsurgery). RESULTS: There was a significant increase in bacterial growth in the AE group compared with the ground control group measured postflight and at necropsy. Simulated AE induced hypoxia with oxygen saturation less than 93%. Supplemental oxygen corrected the hypoxia and significantly reduced bacterial growth in wounds at necropsy. CONCLUSIONS: Hypoxia induced during simulated AE enhances bacterial growth in complex musculoskeletal wounds which can be prevented with the application of supplemental oxygen to the host.

TNF-α induces vectorial secretion of IL-8 in Caco-2 cells.

INTRODUCTION: Intestinal epithelial cells represent an important component of innate immunity, with sophisticated responses to inflammatory stimuli. The manner in which intestinal epithelial cell polarity affects responses to inflammatory stimuli is largely unknown. We hypothesized that polarized intestinal epithelial cells exhibit a bidirectional inflammatory response dependent upon the location of the stimulus. METHODS: Caco-2 cells were grown on semi-permeable inserts in a dual-compartment culture system and treated with tumor necrosis factor-α (TNF-α; 100 ng/ml) or serum-free media in the apical or basolateral chamber. Interleukin-8 (IL-8) production in each chamber was measured by enzyme-linked immunosorbent assay. To determine receptor specificity, anti-TNF receptor antibodies were added to the apical or basolateral chamber. RESULTS: Basolateral stimulation with TNF-α resulted in increased apical and basolateral IL-8 production. Apical TNF-α stimulation resulted in increased apical, but not basolateral IL-8 production. Receptor blockade suggested TNF receptor 1 involvement on both apical and basolateral membranes, while TNF receptor 2 was only active on the apical membrane. CONCLUSION: Polarized intestinal epithelial cells respond to TNF-α stimulation with focused, directional secretion of the proinflammatory cytokine IL-8. These findings are important because they suggest that intestinal epithelial cells are capable of organizing their response to inflammatory signals and producing inflammatory mediators in a bidirectional, vectorial fashion.