Multimodal decoding of human liver regeneration.

The liver has a unique ability to regenerate1,2; however, in the setting of acute liver failure (ALF), this regenerative capacity is often overwhelmed, leaving emergency liver transplantation as the only curative option3-5. Here, to advance understanding of human liver regeneration, we use paired single-nucleus RNA sequencing combined with spatial profiling of healthy and ALF explant human livers to generate a single-cell, pan-lineage atlas of human liver regeneration. We uncover a novel ANXA2+ migratory hepatocyte subpopulation, which emerges during human liver regeneration, and a corollary subpopulation in a mouse model of acetaminophen (APAP)-induced liver regeneration. Interrogation of necrotic wound closure and hepatocyte proliferation across multiple timepoints following APAP-induced liver injury in mice demonstrates that wound closure precedes hepatocyte proliferation. Four-dimensional intravital imaging of APAP-induced mouse liver injury identifies motile hepatocytes at the edge of the necrotic area, enabling collective migration of the hepatocyte sheet to effect wound closure. Depletion of hepatocyte ANXA2 reduces hepatocyte growth factor-induced human and mouse hepatocyte migration in vitro, and abrogates necrotic wound closure following APAP-induced mouse liver injury. Together, our work dissects unanticipated aspects of liver regeneration, demonstrating an uncoupling of wound closure and hepatocyte proliferation and uncovering a novel migratory hepatocyte subpopulation that mediates wound closure following liver injury. Therapies designed to promote rapid reconstitution of normal hepatic microarchitecture and reparation of the gut-liver barrier may advance new areas of therapeutic discovery in regenerative medicine.

Early or Late Conversion From Tac-BD to Tac-BD in Renal Transplantation: When is the Right Time?

BACKGROUND: Increasing numbers of renal transplant recipients are converted from Prograf (Astellas Pharma, Tokyo, Japan) (tacrolimus twice daily [Tac-BD]) to Advagraf (Astellas) (tacrolimus once daily [Tac-QD]), but the optimal time for conversion is as yet unclear. This study aimed to investigate the correlation between the time of conversion from Tac-BD to Tac-QD after renal transplant and the dosing requirements, tacrolimus levels, renal function, and clinical outcomes. METHODS: Since September 2008, 125 renal transplant patients were converted from Tac-BD to Tac-QD and followed up for 2 years after conversion. Patients were split into early (0 to 12 months) and late (>12 months) conversion groups. Demographics, Tac-QD dose, trough levels, graft function, and patient and graft outcome were prospectively collected. RESULTS: Forty-four patients (35.2%) were converted early (3.82 ± 3.24 months), whereas 81 (64.8%) patients were converted late (77.35 ± 53.71 months). Tac-BD dose before conversion was higher in the early group (8.70 ± 6.34 vs 4.44 ± 2.15 mg) as was the initial Tac-QD dose (8.66 ± 6.20 vs 4.37 ± 2.04 mg, P < .0001), and remained higher for 18 months after conversion, as did the serum tacrolimus trough level levels. Renal function, acute rejection, and patient and graft survival were comparable between the groups. CONCLUSIONS: Patients can be safely converted to Tac-QD within the first year post-transplantation, without adverse effects on clinical outcome, despite the higher doses and tacrolimus levels for the first 18 months.

In situ normothermic regional perfusion for controlled donation after circulatory death--the United Kingdom experience.

Organs recovered from donors after circulatory death (DCD) suffer warm ischemia before cold storage which may prejudice graft survival and result in a greater risk of complications after transplant. A period of normothermic regional perfusion (NRP) in the donor may reverse these effects and improve organ function. Twenty-one NRP retrievals from Maastricht category III DCD donors were performed at three UK centers. NRP was established postasystole via aortic and caval cannulation and maintained for 2 h. Blood gases and biochemistry were monitored to assess organ function. Sixty-three organs were recovered. Forty-nine patients were transplanted. The median time from asystole to NRP was 16 min (range 10-23 min). Thirty-two patients received a kidney transplant. The median cold ischemia time was 12 h 30 min (range 5 h 25 min-18 h 22 min). The median creatinine at 3 and 12 months was 107 µmol/L (range 72-222) and 121 µmol/L (range 63-157), respectively. Thirteen (40%) recipients had delayed graft function and four lost the grafts. Eleven patients received a liver transplant. The first week median peak ALT was 389 IU/L (range 58-3043). One patient had primary nonfunction. Two combined pancreas-kidney transplants, one islet transplant and three double lung transplants were performed with primary function. NRP in DCD donation facilitates organ recovery and may improve short-term outcomes.

Dual temperature multi-organ recovery from a Maastricht category III donor after circulatory death.

Donation after circulatory death (DCD) makes a significant contribution to the transplant activity but is associated with significantly lower organ recovery rates and poorer function for the abdominal extra-renal organs compared with donation after brain death. Traditionally, DCD organ recovery involves cold thoracic and abdominal perfusion with a rapid removal of organs in order to minimize the ischemic damage. Novel approaches to organ recovery and preservation include the use of normothermic regional perfusion in the donor and ex vivo organ preservation. We report a new technique for multi-organ recovery from Maastricht category III donors with abdominal normothermic perfusion and concomitant cold lung flushing which allows a rapid removal of the lungs with preservation of the abdominal normothermic circulation throughout the thoracic procurement. This approach could lead to an increased organ recovery and better function for the abdominal organs.

Conversion from twice-daily to once-daily tacrolimus in simultaneous pancreas-kidney transplant patients.

BACKGROUND: Data on the effectiveness of once-daily tacrolimus (Tac-QD) in simultaneous pancreas-kidney (SPK) transplant patients are limited, which is of particular concern because diabetic gastroparesis may affect absorption. The aim of this study was to evaluate the clinical impact of converting SPK patients from twice-daily (Tac-BD) to Tac-QD. METHODS: From November 2008 to August 2011, 27 SPK recipients (out of 130) were converted from Tac-BD to Tac-QD. Demographics, prescribed doses, trough levels, and creatinine, glucose, and HbA1c values were collected prospectively at the time of conversion and at 1, 2, 3, 6, and 12 months after conversion. RESULTS: The mean time from transplantation to conversion was 35.81 ± 27.31 months, with 20 patients (74.07%) converted to Tac-QD >12 months after transplantation. There were no significant differences in the tacrolimus dose and trough levels before and after conversion and at all points during the follow-up. Creatinine, glucos,e and HbA1c levels remained stable throughout. Eight patients (29.63%) with gastroparesis had clinical outcomes, drug doses, and trough levels similar to all other patients. CONCLUSIONS: Stable SPK recipients can safely be converted from Tac-BD to Tac-QD, with no clinical impact on the transplant function. Gastroparesis does not appear to influence tacrolimus dose requirements or trough levels.

Impact of patient characteristics and comorbidity profile on activation of patients on the kidney transplantation waiting list.

BACKGROUND: The aim of this study was to examine which demographic and comorbidity factors affected the activation of patients with end-stage renal disease on the national kidney transplantation waiting list. METHODS: This was a prospective cohort study across 13 transplantation centers in the United Kingdom from October 1, 2006 to September 30, 2007. Data were collected for all new adult patients (n = 1530) referred to the renal transplantation assessment clinic. The proportion of patients who were activated to the waiting list after a minimum one year follow-up was estimated. Factors influencing activation of patients on the waiting list were examined. RESULTS: A total of 872 (58.9%) patients were activated to the transplantation waiting list. The likelihood of activation to the transplantation waiting list was lower in patients older than 65 years (P = .021), nonwhite ethnicity (P < .0001), smokers (P < .0001), and those in whom diabetes was the cause of renal failure (P = .004). Multivariate analysis showed that there was an adverse impact of comorbidity such as ischemic heart disease (P = .003), diabetes (P = .006), and peripheral vascular disease (P = .007) on the likelihood of activation to the waiting list. CONCLUSION: Patient characteristics and comorbidity are associated with the probability of activation of patients to the waiting list.

Does national sharing of kidneys donated after cardiac death lead to poorer outcomes?

BACKGROUND: Kidneys donated after cardiac death (DCD) represent an increasing proportion of transplant activity. There have been concerns that wider sharing of these kidneys increases the cold ischemic time (CIT) and leads to poorer outcomes. METHODS: DCD kidney transplantation was implemented in Scotland in 2005, with each center transplanting locally donated kidneys. A national sharing scheme of DCD kidneys was introduced in 2007, whereby kidneys are shared between the 2 renal transplant centers in the country. A single national multiorgan retrieval team carries out retrievals and kidneys are shipped directly to the 2 units. Donor and recipient demographic data, cold ischemic time, and outcome data were prospectively collected and compared within each center and between centers pre- and postintroduction of the sharing policy. RESULTS: Since 2005, 152 DCD kidney transplants have been performed. Since 2007, 68 kidneys were shared between the centers. Recipient demographics were comparable before and after the introduction for the sharing scheme. The CIT was significantly higher in Glasgow (14.30 ± 3.79 hours) compared with Edinburgh (10.72 ± 2.99 hours; P < .001, one-way analysis of variance [ANOVA] prior to the introduction of the sharing scheme. Following the implementation of kidney sharing, there was no significant difference in CIT between Glasgow and Edinburgh (10.50 ± 3.34 hours vs 10.53 ± 2.71 hours). A significant reduction in the CIT in Glasgow was noted after sharing was instituted (from 14.30 ± 3.79 hours to 10.50 ± 3.34 hours, P < .001, one-way ANOVA). Patient and graft survivals, acute rejection, and delayed graft function as well as 1-year renal function were comparable in both centers before and after the introduction of the scheme. CONCLUSION: Wider sharing of DCD kidneys should be encouraged, as it does not compromise clinical outcomes. A transparent and well-established sharing agreement, with no delays in the offering of DCD kidneys, may lead to an improvement in CIT.

Trends in oesophago-gastric surgery in Scotland.

BACKGROUND: The last twenty years have seen significant changes in both the incidence and treatment of gastro-oesophageal disorders as well as a process of subspecialisation in general surgery. The aim of this study is to identify the changes in gastro-oesophageal surgery in Scotland during this period. METHODS: A retrospective analysis of three years of data, taken over a 20-year period (1977, 1987 and 1997) obtained from the Information and Statistics Division of the Scottish National Health Service, examining the number of patients with oesophageal cancer, gastric cancer and gastro-oesophageal reflux disease (GORD) treated by general and thoracic surgeons. RESULTS: There was a significant increase (p=0.001, chi2) in the number of patients with oesophageal cancer (2.52-fold) and gastric cancer (1.4-fold) treated by general compared with thoracic surgeons. Since 1977, the overall operability for oesophageal cancer has remained unchanged, while a significant decrease in the overall operability of gastric cancer was noted (p<0.001, chi2). There was a 3-fold increase in the incidence of GORD with a significant increase (p<0.001, chi2) of those treated surgically. Since 1977, there has also been a significant shift of workload from thoracic to general surgical units. CONCLUSIONS: Scotland has seen a consistent increase in the surgical workload generated by gastro-oesophageal malignancies over the last three decades without any improvement in the operability rate. Surgically treated GORD has also increased, probably due to the introduction of minimally invasive techniques. These trends have implications on healthcare planning, resource allocation and surgical training. Appropriate resources and trainees should follow the patients to those units carrying out this activity. Further centralisation of these services is likely to follow.

Functional results following pharyngolaryngooesophagectomy with free jejunal graft reconstruction.

OBJECTIVE: A free jejunal graft is used for reconstruction following pharyngolaryngooesophagectomy, due to the relative ease of harvesting, low donor site morbidity and a lumen diameter compatible with that of the oesophagus. Our aim is to evaluate the postoperative outcome and functional results of the procedure. METHODS: Retrospective analysis of 20 consecutive patients, with a mean age of 62.5 years (range 48--76), who underwent free jejunal reconstruction following pharyngolaryngooesophagectomy for laryngeal malignancy. Surgery was performed secondary to radiotherapy or as the main stem of treatment. The functional results were assessed at 6 months and 1 year and correlated with postoperative morbidity. Chi-square test was used for statistical significance and Kaplan--Meyer to estimate survival. RESULTS: There were six transient leaks and six cases with anastomotic stricture. There was no morbidity associated with the donor site and the perioperative mortality (30 days) was zero. At 6 months, 13 (87%) out of the 15 patients alive had satisfactory speech and 11 (78%) had satisfactory swallowing. At 1 year, 11 patients were alive and maintained a satisfactory speech, while nine (81%) of them were eating well. The incidence of leaks, strictures, or the moment of radiotherapy has no influence on the functional outcome. The 1- and 3-year survival rates were 52.3 and 33.2%, respectively. CONCLUSIONS: A free jejunal graft reconstruction is technically demanding, but provides a near-physiologic swallowing mechanism, avoiding the complications of a gastric pull-up procedure. Functional results are good and justify the procedure despite the relatively high co-morbidity.