The evolving microenvironment of the human hepatocyte: Healthy vs. cirrhotic liver vs. isolated cells.

The study of the liver microenvironment and hepatocyte's response to this environment in the setting of healthy liver, cirrhotic liver or cultured primary human hepatocytes (PHHs) addresses key questions for the development of novel liver therapies and predicts relevance of ex vivo PHHs models in liver biology. This study compared quantitative gene and protein expression of the inflammatory profile, oxidative stress response, angiogenesis and homing mechanisms in the biopsies of healthy and cirrhotic human livers and isolated PHHs. These profiles were correlated with the metabolic health of liver and PHHs defined by albumin production. The analysis demonstrated that cirrhotic liver and PHHs exhibited a distinct upregulation of the pro-inflammatory, oxidative stress and homing mechanism markers when compared to normal liver. The upregulation of the oxidative stress markers in PHHs inversely correlated with the albumin production. PHHs had diverse secretion of matrix metalloproteinases and their inhibitors, reflective of the cellular response to non-physiological culture conditions. The current study suggests that ex vivo PHHs manifest adaptive behavior by upregulating stress mechanisms (similar to the cirrhotic liver), downregulating normal metabolic function and upregulating matrix turnover. The ex vivo profile of PHHs may limit their therapeutic functionality and metabolic capacity to serve as in vitro metabolism and toxicology models.

Dual-graft adult living donor liver transplantation with ABO-incompatible graft: short-term and long-term outcomes.

ABO-incompatible (ABOi) dual-graft (DG) adult living donor liver transplantation (ALDLT) is not commonly performed due to its inherently intricate surgical technique and immunological complexity. Therefore, data are lacking on the short- and long-term clinical outcomes of ABOi DG ALDLT. We performed a retrospective study by reviewing the medical records of patients who underwent ABOi DG ALDLT between 2008 and 2014. Additionally, computed tomography volumetric analysis was conducted to assess the graft regeneration rate. The mean age of a total of 28 recipients was 50.2 ± 8.5 years, and the mean model for end-stage liver disease score was 12.2 ± 4.6. The 1-, 3-, and 5-year patient survival rate was 96.4% during the mean follow-up period of 57.0 ± 22.4 months. The 1-, 3-, and 5-year graft survival rate was 96.4%, 94.2%, and 92.0%, respectively, and no significant differences were observed between ABO-compatible (ABOc) and ABOi grafts (P = .145). The biliary complication rate showed no significant difference (P = .195) between ABOc and ABOi grafts. Regeneration rates of ABOi grafts were not significantly different from those of ABOc grafts. DG ALDLT with ABOi and ABOc graft combination seems to be a feasible option for expanding the donor pool without additional donor risks.

Living Donor Liver Transplantation for Patients Older Than Age 70 Years: A Single-Center Experience.

Over the past two decades, the age of liver transplantation (LT) recipients has been increasing. We reviewed our experience with LT for patients aged ≥70 years (range: 70-78 years) and investigated the feasibility of performing LT, especially living donor LT (LDLT), for older patients. We retrospectively reviewed the medical records of 25 patients (15 LDLT recipients, 10 deceased donor LT recipients) aged ≥70 years who underwent LT from January 2000 to April 2016. Their perioperative morbidity rate was 28.0%, and the in-hospital mortality rate was 16.0%; these results were comparable to those of matched patients in their 60s (n = 73; morbidity, p = 0.726; mortality, p = 0.816). For patients in their 70s, the 1- and 5-year patient survival rates were 84.0% and 69.8%, and the 1- and 5-year graft survival rates were 83.5% and 75.1%, respectively. Comparisons of patient and graft survival rates between matched patients in their 60s and 70s showed no statistically significant differences (patient survival, p = 0.372; graft survival, p = 0.183). Our experience suggests that patients aged ≥70 years should not be excluded from LT, or even LDLT, based solely on age and implies that careful selection of recipients and donors as well as meticulous surgical technique are necessary for successful results.

Genetic Traits in the Liver Anatomy Between Parents and Children: An Analysis of Liver Transplant Recipients and Living Donors.

BACKGROUND: To date, no significant similarities in the anatomy of the hepatic vasculature have been observed between blood-related individuals. However, we have frequently encountered anatomic similarities between parents and their children; thus, we performed an analysis of the genetic traits in the anatomy of the liver. METHODS: The study cohort was 330 adult cases of living-donor liver transplantation (LDLT), in which the donor-recipient relationship was child to parent. The subjects underwent LDLT from January 2013 to December 2014. Preoperative dynamic computerized tomographic scans were used to classify the anatomy of the hepatic vasculature. RESULTS: Portal vein (PV) anatomy was classified as typical and 2 variant types. PV anatomy combinations in donor and recipient were typical in 232 subjects, variant in 16, and typical-variant in 82. The PV concordance rate was 75.2%, and the contingency coefficient was 0.130 (P = .017). Hepatic artery (HA) anatomy was classified as typical and 4 variant types. HA anatomy combinations in donor and recipient were typical in 167 subjects, variant in 33, and typical-variant in 130. The HA concordance rate was 60.6%, and the contingency coefficient was 0.058 (P = .294). The sizable inferior right hepatic vein in donor and recipient was present in 44 subjects, absent in 160, and discordant in 126; its concordance rate was 61.8% and contingency coefficient 0.133 (P = .014). CONCLUSIONS: There may be a shared but weak genetic trait between parents and children regarding the anatomy of the PV and inferior hepatic vein. This information may be helpful when LDLT is performed between 1st-degree relatives.

Surgical protocol involving the infusion of paramagnetic microparticles for preferential incorporation within porcine islets.

INTRODUCTION: Despite significant advances, widespread applicability of islet cell transplantation remains elusive. Refinement of current islet isolation protocols may improve transplant outcomes. Islet purification by magnetic separation has shown early promise. However, surgical protocols must be optimized to maximize the incorporation of paramagnetic microparticles (MP) within a greater number of islets. This study explores the impact of MP concentration and infusion method on optimizing MP incorporation within islets. METHODS: Five porcine pancreata were procured from donors after cardiac death. Splenic lobes were isolated and infused with varying concentrations of MP (8, 16, and 32 × 10(8) MP/L of cold preservation solution) and using one of two delivery techniques (hanging bag versus hand-syringe). After procurement and infusion, pancreata were stored at 0°C to 4°C during transportation (less than 1 hour), fixed in 10% buffered formalin, and examined by standard magnetic resonance imaging (MRI) and histopathology. RESULTS: T2*-weighted MRI showed homogeneous distribution of MP in all experimental splenic lobes. In addition, histologic analysis confirmed that MP were primarily located within the microvasculature of islets (82% to 85%), with few MP present in acinar tissue (15% to 18%), with an average of five to seven MP per islet (within a 5-µm thick section). The highest MP incorporation was achieved at a concentration of 16 × 10(8) MP/L using the hand-syringe technique. CONCLUSION: This preliminary study suggests that optimization of a surgical protocol, MP concentrations, and applied infusion pressures may enable more uniform distribution of MP in the porcine pancreas and better control of MP incorporation within islets. These results may have implications in maximizing the efficacy of islet purification by magnetic separation.

Anti-CD25 antibody (daclizumab) maintenance therapy in pancreas transplantation.

BACKGROUND: Calcineurin inhibitors (CNI) are the basis of contemporary immunosuppression in clinical pancreas transplantation (PT). Nevertheless, CNI toxicities, especially nephrotoxicity, have stimulated the search for CNI-sparing protocols. We performed a retrospective analysis of 25 PT patients with progressive CNI toxicities that were switched to a daclizumab (DAC)-based maintenance regimen. METHODS: From 2003 to 2007, 25 PT patients with progressive CNI toxicity (predominantly nephrotoxicity) were identified and switched from CNI to monthly DAC maintenance therapy. The DAC group was compared with matched control subjects (1:1) by transplant type and number, age, year of transplant, and duct management. RESULTS AND CONCLUSIONS: Results showed improved graft survival rates and decreased immunologic loss rates at 1, 3, and 5 years in the DAC group compared with the control group. There was no difference in patient survival rate between the 2 groups. Analysis demonstrates that DAC maintenance therapy is safe and effective for PT patients experiencing CNI toxicities. A randomized trial to compare DAC- and CNI-based regimens is needed in CNI-intolerant patients, with particular attention to the impact on renal function and patient morbidity (eg, infection rates).

Pancreas oxygen persufflation increases ATP levels as shown by nuclear magnetic resonance.

BACKGROUND: Islet transplantation is a promising treatment for type 1 diabetes. Due to a shortage of suitable human pancreata, high cost, and the large dose of islets presently required for long-term diabetes reversal; it is important to maximize viable islet yield. Traditional methods of pancreas preservation have been identified as suboptimal due to insufficient oxygenation. Enhanced oxygen delivery is a key area of improvement. In this paper, we explored improved oxygen delivery by persufflation (PSF), ie, vascular gas perfusion. METHODS: Human pancreata were obtained from brain-dead donors. Porcine pancreata were procured by en bloc viscerectomy from heparinized donation after cardiac death donors and were either preserved by either two-layer method (TLM) or PSF. Following procurement, organs were transported to a 1.5-T magnetic resonance (MR) system for (31)P nuclear magnetic resonance spectroscopy to investigate their bioenergetic status by measuring the ratio of adenosine triphosphate to inorganic phosphate (ATP:P(i)) and for assessing PSF homogeneity by MRI. RESULTS: Human and porcine pancreata can be effectively preserved by PSF. MRI showed that pancreatic tissue was homogeneously filled with gas. TLM can effectively raise ATP:P(i) levels in rat pancreata but not in larger porcine pancreata. ATP:P(i) levels were almost undetectable in porcine organs preserved with TLM. When human or porcine organs were preserved by PSF, ATP:P(i) was elevated to levels similar to those observed in rat pancreata. CONCLUSION: The methods developed for human and porcine pancreas PSF homogeneously deliver oxygen throughout the organ. This elevates ATP levels during preservation and may improve islet isolation outcomes while enabling the use of marginal donors, thus expanding the usable donor pool.

Persufflation improves pancreas preservation when compared with the two-layer method.

Islet transplantation is emerging as a promising treatment for patients with type 1 diabetes. It is important to maximize viable islet yield for each organ due to scarcity of suitable human donor pancreata, high cost, and the large dose of islets required for insulin independence. However, organ transport for 8 hours using the two-layer method (TLM) frequently results in low islet yields. Since efficient oxygenation of the core of larger organs (eg, pig, human) in TLM has recently come under question, we investigated oxygen persufflation as an alternative way to supply the pancreas with oxygen during preservation. Porcine pancreata were procured from donors after cardiac death and preserved by either TLM or persufflation for 24 hours and subsequently fixed. Biopsies collected from several regions of the pancreas were sectioned, stained with hematoxylin and eosin, and evaluated by a histologist. Persufflated tissues exhibited distended capillaries and significantly less autolysis/cell death relative to regions not exposed to persufflation or to tissues preserved with TLM. The histology presented here suggests that after 24 hours of preservation, persufflation dramatically improves tissue health when compared with TLM. These results indicate the potential for persufflation to improve viable islet yields and extend the duration of preservation, allowing more donor organs to be utilized.

Continuous real-time viability assessment of kidneys based on oxygen consumption.

BACKGROUND: Current ex vivo quality assessment of donor kidneys is limited to vascular resistance measurements and histological analysis. New techniques for the assessment of organ quality before transplantation may further improve clinical outcomes while expanding the depleted deceased-donor pool. We propose the measurement of whole organ oxygen consumption rate (WOOCR) as a method to assess the quality of kidneys in real time before transplantation. METHODS: Five porcine kidneys were procured using a donation after cardiac death (DCD) model. The renal artery and renal vein were cannulated and the kidney connected to a custom-made hypothermic machine perfusion (HMP) system equipped with an inline oxygenator and fiber-optic oxygen sensors. Kidneys were perfused at 8 degrees C, and the perfusion parameters and partial oxygen pressures (pO(2)) were measured to calculate WOOCR. RESULTS: Without an inline oxygenator, the pO(2) of the perfusion solution at the arterial inlet and venous outlet diminished to near 0 within minutes. However, once adequate oxygenation was provided, a significant pO(2) difference was observed and used to calculate the WOOCR. The WOOCR was consistently measured from presumably healthy kidneys, and results suggest that it can be used to differentiate between healthy and purposely damaged organs. CONCLUSIONS: Custom-made HMP systems equipped with an oxygenator and inline oxygen sensors can be applied for WOOCR measurements. We suggest that WOOCR is a promising approach for the real-time quality assessment of kidneys and other organs during preservation before transplantation.