Microcirculatory disturbances and leucocyte adherence in transplanted livers after cold storage in Euro-Collins,UW and HTK solutions

Integrity of the hepatic microcirculation and maintenance of endothelial cell viability are critical components in preventing primary non-function after liver transplantation. Therefore, hepatic microcirculation and leucocyte-endothelial interaction were studied in rat livers stored for 1 h in Euro-Collins (EC), University of Wisconsin (UW), and histidine-tryptophan-ketoglutarate (HTK) solutions and subsequently transplanted. One hour after transplantation surgery, the livers were exposed under an intravital fluorescence microscope. After injection of the leucocyte marker acridine orange (1 mol/kg), six pericentral fields were observed for 30 s and experiments were recorded continuously. The percentage of perfused sinusoids was reduced in the livers in the EC group (82.9%) in contrast to the UW (93.2%) and HTK groups (91.0%). Livers in the EC group showed a reduction in the diameters of pericentral sinusoids (7.3±0.2 m; mean±SEM) compared with the UW group (9.5±0.2 m; P<0.05) and HTK group (10.2±0.8 m; P<0.05), indicating substantial cell swelling in livers stored in EC solution. Permanent adherence of leucocytes was most frequently observed in the EC group (33.5±1%), while this phenomenon was less pronounced in the UW group (14.5+1.1%; P<0.05) and HTK group (16.3±0.7%; P<0.05). Conversely, temporary adherence of leucocytes was reduced in the EC group (19.7+1.3%) compared with the UW group (30.5+2.1%) and the HTK group (34.4+0.8%). Microcirculatory failure and cell swelling in the EC group might be due to the lack of osmotic substances or oxygen radical scavengers included in UW (allopurinol, glutathione) and HTK (mannitol) solutions. In conclusion, cold storage of livers in UW and HTK solutions results in better preservation of the microcirculation and prevention of adhesion of leucocytes after transplantation compared with the EC solution.     

Liberation of vasoactive substances and its prevention with thromboxane A2 synthase inhibitor in pig liver transplantation

There are multiple causes of liver graft nonfunction in the early post-transplant period. Since a severe microcirculatory disturbance based on ischemia-reperfusion liver injury is considered to be the main underlying pathophysiology, it is suspected that various vasoactive substances are liberated after reperfusion of the graft. In order to investigate this matter, we conducted an experimental study with pig liver allotransplantation. Two groups of animals received donor grafts with or without thromboxane synthase inhibitor (sodium ozagrel), 1.25 mg/kg body weight intravenously, given at the time of liver harvesting. All of the recipient animals in the treatment group (n=10) survived longer than 7 days whereas three of ten animals in the control group died within 7 days. Serum lactate dehydrogenase (LDH) in the recipient serum at 1 h after reperfusion was significantly lower in the treatment group (915.1±167.3 U/l) than in the control group (1264.4±134.7 U/l). Serum thromboxane B₂ (2261.7±1055.7 pg/ml) and endothelin-1 (6.3±2.2 pg/ml) after reperfusion in the treatment group were significantly lower than those in the control group (4220.0±1711.0 pg/ml and 11.2±3.1 pg/ml, respectively). Although serum angiotensin II after reperfusion tended to be lower in the treatment group than in the controls serum renin activity was less than 3 ng/ml in both groups of animals. There were no differences in the plasma endotoxin levels between the two groups. We conclude that the administration of sodium ozagrel to the donor animals provided better graft function in recipients than no such treatment. We speculate that the inhibition of thromboxane A₂ production suppresses the liberation of other vasoconstrictive substances, preventing microcirculatory disturbance and, thereby, contributing to improved graft function after liver transplantation.     

Quantitative measurements of collateral arterial blood flow in nonarterialized rat liver grafts

The early development of arterial blood flow in the grafted liver after orthotopic liver transplantation in the rat without reconstruction of the hepatic artery was studied. Arterial liver blood flow was measured on day 21 after transplantation with NEN-TRAC microspheres (size 15.5±0.1 m) and labelled with ¹⁰³Ru. The arterial liver blood flow in the grafted liver was 0.778±0.247 ml/min per gram for transplanted rats after 21 days. One day after transplantation, the blood flow was only 0.006±0.002 ml/min per gram. The results of this study demonstrate that there was no arterial blood flow on day 1 after transplantation, as expected, but that there was a high arterial blood flow in the transplanted liver by day 21. This was also supported by the angiographic findings. The early development of arterial blood flow via collaterals may account for the excellent results that we and others have attained in orthotopic liver transplantation without rearterialization in the rat.     

The significance of tissue-type plasminogen activator for pretransplant assessment of liver graft viability: analysis of effluent from the graft in rats

We studied the significance of tissue-type plasminogen activator (tPA) on the pretransplant assessment of liver graft viability in rats. The liver grafts were excised from the rats and then divided into two groups. Group 1 consisted of grafts preserved for 4 h in chilled, lactated Ringer's solution (4°C) and group 2 consisted of grafts preserved for 6 h in the same solution. After preservation, the liver grafts were flushed out through the portal vein using 5 ml of chilled, lactated Ringer's solution (4°C). The entire effluent from the hepatic veins was then collected and analyzed for tPA, ammonia, lactate, pyruvate, glutamic oxaloacetic transaminase, and lactate dehydrogenase. The tPA concentration of effluent in group 2 was significantly higher than that in group 1 (0.80±0.23 ng/ml vs 0.42±0.08 ng/ml, P<0.05). The lactate, pyruvate, and ammonia levels in group 2 were also higher than those in group 1 (134±13 mg/dl vs 120±2 mg/dl, 0.34±0.40 mg/dl vs 0.09±0.01 mg/dl, and 183±79 g/dl vs 102±40 g/dl, respectively). However, the discriminative power of tPA was stronger than that of the other parameters. Histological findings revealed a higher number of trypan blue-stained sinusoidal lining cells that were detached and swollen in group 2. We conclude that the amount of tPA in the effluent flushed from the graft can serve as a sensitive and reliable indicator of cold-preserved liver grafts in rats.     

Raised pressure in the bile ducts after orthotopic liver transplantation

Biliary complications are common after orthotopic liver transplantation. Bile leakage in the immediate postoperative period and on removal of the T-tube could possibly be caused by a raised bile duct pressure. In order to test this hypothesis, bile duct pressure was studied in seven consecutive liver transplant patients. During the operation, the common bile duct was anastomosed end-to-end over a T-tube. The initial bile duct pressure measurement was performed a median of 12 days (range 10–17 days) after the transplantation and on one or two more occasions during the following 3 months. Seven cholecystectomized gallstone patients with indwelling T-tubes were used as controls. The bile duct pressure at the level of the xiphoid process in the transplanted group was 7.7±1.4 cm H₂O and in the control group 0.5±0.8 cm H₂O (P<0.001). The initially increased bile duct pressure after liver transplantation decreased with time (P<0.05) towards normal during the following 3 months. The raised pressure may increase the risk of bile leakage in the postoperative period.     

Suppression of liver allograft rejection by administration of 15-deoxyspergualin

In this experiment, the effect of the administration route-the hepatic artery, portal vein, or systemic circulation-of the immunosuppressive drug 15-deoxyspergualin (DSG) on the suppression of liver allograft rejection is investigated. A 3-day injection of DSG at a dose of 0.32–1.28 mg/kg per day into the systemic circulation of a rat that had received a liver transplant was not effective in prolonging liver graft survival (14.3±2.9 days vs. 14.1±2.5 days for controls). However, the administration of DSG into the portal vein following liver transplantation markedly prolonged survival for up to 24.9±10.0 days. Survival times were prolonged even more when the DSG was administered via the hepatic artery for 3 successive days after liver grafting (30.9±9.6 days). The concentration of DSG in the blood following the one-shot injection of DSG was highest when DSG was administered via the hepatic artery, intermediate when injected into the portal vein, and lowest when injected into the systemic vein. In conclusion, DSG can inhibit liver graft rejection more effectively via the hepatic arterial route than via the portal vein or systemic circulation.     

The immunosuppressive effects of a leukotriene B4 receptor antagonist on liver allotransplantation in rats

The immunosuppressive effects of a leukotriene B₄ (LTB₄) receptor antagonist, ONO4057, on liver allotransplantation in rats were evaluated, and the levels of prostaglandin E₂ (PGE₂) in the liver tissue during rejection of the allografts examined. The rats were divided into four groups: group 1: Lewis rats (LEW) given a sham operation with dimethyl sulfoxide (DMSO); group 2: LEW given syngenic orthotopic liver transplantation (OLT) from LEW, with DMSO; group 3: LEW given allogenic OLT from ACI rats (ACI), with DMSO; and group 4: LEW given allogenic OLT from ACI, with ONO4057 as 10, 30, or 100 mg/kg per day dissolved in DMSO to subgroups 4a, 4b, and 4c, respectively. Histological examinations were performed, survival times monitored, and liver tissue PGE₂ levels 3, 5, 7, and 14 days after transplantation measured. The mean graft survival times in groups 4a, b, and c, at 37.5±10.4, 52.2±24.4, and 34.0±4.9 days (mean±SEM), respectively, were significantly longer than that in group 3 (at 13.0±3.2 days). Moreover, the levels of tissue PGE₂ in the liver allografts in group 4a were significantly higher than those in group 3 on days 5 and 7. These results suggest that ONO4057 has an immunosuppressive effect on liver allotransplantation since it reduces the activities of LTB₄ which augments immune responses, and also because it indirectly increases the PGE₂ level.     

Evidence that both cyclosporin and azathioprine prevent warm ischemia reperfusion injury to the rat liver

The present work was undertaken to study whether the immunosuppressive agents cyclosporin (CyA) and azathioprine (AZA) ameliorate hepatic injury after warm ischemia. A temporary, normothermic liver ischemia was induced in female Sprague-Dawley rats. The rats were treated with CyA (10 mg/kg per day p.o.), AZA (8 mg/kg per day p.o.), or vehicles for 4 days before surgery. Seven-day survival rates after 60 min of ischemia improved significantly with CyA (76.2%, P<0.005) and AZA (78.6%, P<0.001) treatment, compared with 43.0% for the control group. The highest levels of serum aminotransferases in the treatment groups tended to be lower than those in the control group. The peak values for the percentage of liver necrosis, an indicator of the extent of hepatic necrosis, in the animals treated with CyA (26.1%±7.2%, mean±SEM) and AZA (32.1%±5.7%) were significantly lower than in the control group (47.4%±3.7%). Lipid peroxidative damage after reperfusion, assessed as the hepatic malondialdehyde (MDA) concentration, was significantly suppressed by pretreatment with CyA and AZA. Histological findings coincided with other parameters. This study demonstrates that both AZA and CyA have beneficial effects on normothermic liver ischemia in rats. It is suggested that the diminished lipid peroxidative damage with these agents might be one of the mechanisms responsible for this.     

Plasma levels of parathyroid hormone,vitamin D,calcitonin, and calcium in association with endurance exercise

Summary Nine male marathon runners were investigated during habitual training (week 0), after 3 weeks of training break (week 3), and after 2 weeks (week 5) and 4 weeks (week 7) of retraining. Maximal oxygen uptake, body fat (BF), and plasma levels of 25(OH)D₃, 1,25(OH)₂D₃, parathyroid hormone (PTH), calcitonin (CT), albumin, and albumincorrected calcium were determined throughout weeks 0–7. The maximal oxygen uptake decreased after training break and increased during retraining (P=0.002). BF did not change significantly. Plasma 1,25(OH)₂D₃ was elevated after training break and decreased after 2 and 4 weeks of retraining [week 0: 44.0±3.7 (SEM) pg×1^-1; week 3: 52.4±6.0 pg×1^-1; week 5: 42.0±2.8 pg×1^-1; week 7: 36.9±2.3 pg×1^-1; P=0.03]. Plasma 25(OH)D₃ did not change significantly. Plasma PTH increased throughout the training break and retraining (week 0: 1.36±0.25 pmol×1^-1; week 3: 2.02±0.43 pmol×1^-1; week 5: 2.23±0.60 pmol×1^-1; week 7: 2.63±0.34 pmol×1^-1; P=0.03). Albumincorrected calcium values were transiently decreased during retraining (week 3: 2.77±0.08 mM; week 5: 2.47±0.05 mM; week 7: 2.66±0.07 mM; P=0.01). Plasma CT did not change during training break, but was transiently decreased during retraining (week 0: 9.97±0.39 pmol×1^-1; week 3: 9.91±0.37 pmol×1^-1; week 5: 8.19±0.50 pmol×1^-1; week 7: 9.02±0.45 pmol×1^-1; P=0.01). Plasma CT was correlated to albumin (r=0.46, P=0.005), albumin-corrected calcium (r=0.34, P=0.04), and maximal oxygen uptake (r=0.45, P=0.006). Plasma 1,25(OH)₂D₃ was correlated to 25(OH)D₃ (r=0.04, P=0.02), and BF (r=0.50, P=0.002). The described endurance training induced significant changes of plasma 1,25(OH)₂D₃ and PTH despite only transient changes of albumin-corrected calcium and CT.     

Intravital studies on beneficial effects of warm Ringer's lactate rinse in liver transplantation

This quantitative in vivo fluorescence microscopy study investigated the impact of warm versus cold Ringer's lactate (RL) graft rinse on various microvascular manifestations of ischemia-reperfusion injury after liver translantation in the rat. Syngeneic orthotopic liver transplantation, including arterial revascularization, was performed in male Lewis rats following 24 h of cold storage in University of Wisconsin (UW) solution. In one group (n=8) liver grafts were rinsed with 4°C (cold) RL, whereas in the other group (n=8) grafts were rinsed with 37°C (warm) RL immediately prior to revascularization. Hepatic microvascular perfusion, leukocyteendothelium interaction, and Kupffer cell activation were quantified 30–90 min after graft reperfusion by direct visualization with intravital fluorescence microscopy. Moreover, biliary excretory graft function was analyzed by determination of bile flow and bile salt excretion during the first 90 min after reperfusion. Compared to grafts rinsed with cold RL, acinar and sinusoidal perfusion were found to be significantly increased after rinsing the grafts with warm RL. The amount of nonperfused acini declined from 18.1%±4.0% to 7.4%±1.6% (P<0.05), and the total percentage of perfused sinusoids increased from 80.1±1.4 to 88.4±1.2 (P<0.001) after cold and warm rinse, respectively. After rinsing the graft with warm RL, WBC adherence in sinusoids and especially in postsinusoidal venules decreased significantly by 28% (P<0.001) and 33% (P<0.001), respectively. Kupffer cell activation was markedly reduced after rinsing with RL at 37°C, as indicated by a decelerated adherence of latex particles injected 80 min after reperfusion. Excretory graft function was dramatically increased following warm RL rinse during the 90-min observation period. Bile flow was enhanced from 1.04±0.5 to 3.9±0.8 ml/100 g liver per 90 min (P<0.01), with a parallel rise in bile salt excretion from 24.3±5.8 to 128.0±19.8 mmol/100 g liver per 90 min (P<0.05) when compared to cold RL. These data strongly suggest that rinsing liver grafts with warm RL prior to reperfusion represents a simple and inexpensive way to reduce the incidence of primary graft failure secondary to ischemia and reperfusion injury in liver transplantation.The results of this study were partly presented at the International Symposium on Transplantation of Abdominal Organs in Essen, Germany, in November 1992 and published in Transplantation Proceedings in 1993.     

Injury to cultured liver endothelial cells during cold preservation: energy-dependent versus energy-deficiency injury

Previously, we demonstrated an energy-dependent injury to cultured liver endothelial cells during cold incubation in University of Wisconsin (UW) solution. Here, the effects of Histidine-Tryptophan-Ketoglutarate (HTK) and Euro-Collins (EC) solutions on these cells were studied. In HTK solution, 83%±4% of the cells had lost viability after 9 h of incubation at 4°C. The addition of cyanide (1 mM) to simulate hypoxic conditions protected the cells to the extent that only 9%±1% of the cells lost viability over the same period; the addition of glucose (10 mM) led to increased cell injury. ATP levels were highest in the incubations with the most rapid loss of viability. In Krebs-Henseleit buffer and EC solution, in contrast, cell injury increased upon addition of cyanide; the addition of glucose to Krebs-Henseleit buffer decreased injury. We conclude that the injury to cultured liver endothelial cells during cold incubation in HTK solution is energy-dependent, as it is in UW solution, whereas cells behave differently in EC solution and Krebs-Henseleit buffer.     

Low-temperature fluorometric technique for evaluating the viability of rat liver grafts after simple cold storage

Time-dependent changes in the viability of rat liver graft during cold preservation with Euro-Collins solution were evaluated with NADH fluorometry. Correlation between the fluorometric analysis, 1-week survival rate after liver transplantation, and mitochondrial ATP synthesis activity in the early phase after transplantation was studied. Fluorometric study: Rat livers were preserved at 0°–4°C for 0–48 h in Euro-Collins solution and then reperfused for 15 min with oxygenated Krebs-Henseleit solution at 4°C. The amplitude (R x A) between the oxidized and the reduced steady-state NADH fluorometric trace and the velocity (R x V) of the trace were determined to evaluate the mitochondrial respiratory chain. The R x A and R x V remained at levels higher than 90% of control after 6-h preservation, while the R x A of the 9-h preservation group and the R x V of the 12-h preservation group decreased significantly compared with those of the control and the 6-h preservation group. Survival study: a 100% survival rate after transplantation was achieved in the 6-h preservation group, whereas the rates were 18.8% and 0% in the 9-and 12-h preservation groups respectively. These survival rates correlated closely with the time-dependent decrease of the fluorometric parameters. Study of mitochondrial phosphorylative activity and energy charge 3 h after transplantation: With fresh grafts, the decrease in hepatic energy charge after transplantation was reduced to 0.79 from the control value of 0.86 by a 30% increase in mitochondrial ATP synthesis ability. When the graft was preserved for 12 h, the energy charge dropped to 0.63 due to lack of the enhancement of ATP synthesis ability. The results of this study indicate a possibility of using fluorometric evaluation of the graft to predict post-transplantation mitochondrial ATP synthesis ability and survival rate.     

An in vitro evaluation of prostaglandin El and E2 on hypothermic injury to immature myocytes

The purpose of this study was to evaluate the functional and biochemical effects of Prostaglandin E₁ (PGE₁) and prostaglandin I₂ (PGI₂) on cardiac myocytes incubated under hypothermic conditions. Cardiac myocytes were isolated from neonatal rat ventricles and cultured for 4 days with MCDB 107 medium. Following this, 12.5 × 105 myocytes/ flask were incubated at 4°C for 24 h in media with PGE₁, at concentrations of 0 M (group E0), 10^–9M (group El), 10^–8M (group E2), 10^–7 M (group E3), or 10^–6 M (group E4); or with PGI₂ at concentrations of 0 M PGI (group I0), 10^–9M (group I1), 10^–8M (group I2), 10^–7 M (group I3), or 10^–6 M (group I4). After hypothermic incubation, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were measured, and the myocytes were then cultured for 24 h at 37°C to evaluate the recovery of the myocyte beating rate. Of the PGI₂ groups, only group 12 recovered significantly more than the control group (group I0), at 47.9 ± 28.5% (mean ± SD) of the control, being the beating rate prior to hypothermic incubation, whereas it was 18.1 ± 9.7% in group I0 (P < 0.025); however, there were no significant differences among the PGE₁ groups. Moreover, the release of CPK and LDH was significantly suppressed in group_I2 compared to the control, being 57.7 ± 27.6 mIU/flask (P < 0.05) and 275.1 ±83.0mIU/flask (P < 0.025), respectively, in group 12, and 96.8 ± 38.3 mIU/flask and 439.6 ± 147.1 mIU/flask in group I0. Again, no significant differences were observed among the PGE₁ groups. In conclusion, PGI2 was found to have a direct cytoprotective effect on immature myocytes which suggests that PGI₂ may promote cardiac preservation in the neonatal period.     

Impact of adhesion molecules of the selectin family on liver microcirculation at reperfusion following cold ischemia

We investigated the role of adhesion molecules in the early phase of reperfusion following cold ischemia. Livers of male Lewis rats were preserved for 0 h (group A) or 24 h in University of Wisconsin (UW) solution without additives (group B) or in UW solution with anti-ICAM-1 antibody (group C) or anti-E-selectin-1, SLe^x and SLe^a antibodies (group D). The livers were then reperfused with diluted rat whole blood (DWB; groups A and B), DWB containing anti-ICAM-1 and LFA-1 antibodies (group C) or DWB containing anti-L-selectin, SLe^x and SLe^a antibodies (group D). The reperfusion was perfomed at 37°C for 1 h at 5 cm H₂O of perfusion pressure. During reperfusion, hepatic microcirculation was assessed by monitoring portal and peripheral tissue blood flow. Bile production was significantly reduced in group B livers compared with those in group A. Anti-ICAM-1 and LFA-1 antibodies failed to improve hepatic microcirculation, whereas anti-LECAM-1, SLe^x and SLe^a antibodies significantly improved the microcirculation. Bile production in group C and D livers was comparable to that in group B livers. Preservation for 24 h significantly increased the release of TNF- from 0.207 to 43.7 pg/g per hour during reperfusion. Monoclonal antibodies to the adhesion molecules did not suppress the release of TNF- in groups C and D. Histological examination demonstrated a lack of leukocyte infiltration or thrombus in hetapic microvessels. The extent of hepatocyte necrosis did not differ among groups B, C, and D. We conclude that the microcirculatory disturbance in the early phase of reperfusion occurs as a result of the tethering of leukocytes through the interaction of the selectin family and their ligands, and that the ICAM-1-LFA-1 pathway is not involved in this step. The lack of improvement in bile production with antibodies to the selectin family and their ligands strongly suggests that other mechanisms participate in the deterioration of hepatic function.     

Increased CXCR3 expression associated with CD3-positive lymphocytes in the liver and biliary remnant in biliary atresia

Background

Lymphocyte-mediated inflammatory damage of the bile ducts has been proposed as a potential mechanism in the pathogenesis of biliary atresia (BA). Chemokines regulate leukocyte migration and act as critical organizers of cell distribution in inflammatory responses. The aim of this study was to analyze the infiltration of T lymphocytes and the expression of a chemokine receptor, CXCR3, predominantly expressed on type 1 polarized T cells (T_H1, T_C1) in the liver and excised biliary remnants in infants with BA.

Methods

Immunohistochemistry for CD3, CD8, and CXCR3 was performed using liver biopsy specimens collected from the following 3 age-matched groups of patients: group 1, BA (nonsyndromic) at the time of Kasai portoenterostomy (n = 10); group 2, congenital choledochal dilatation (n = 2); and group 3, other cholestatic diseases including paucity of intrahepatic bile ducts and cholestasis (n = 3) related to total parenteral nutrition. Cellular staining on each section was graded from 0 to 4 and compared using nonparametric statistics.

Results

Infiltrating CD3⁺ and CD8⁺ lymphocytes in the portal tracts were significantly increased in group 1 (3.1 ± 0.4, 2.8 ± 0.4), compared with groups 2 (1.0 ± 0.0, 1.0 ± 0.0) and 3 (1.7 ± 0.3, 1.5 ± 0.5) (P < .01, P < .05). CXCR3⁺ mononuclear cells were significantly increased in group 1 (2.6 ± 0.3) compared with groups 2 (0.5 ± 0.5) and 3 (0.7 ± 0.3) (P < .05). They were mainly found in the portal tracts with a similar distribution to CD3⁺ cells. CXCR3⁺ cells and CD3⁺ cells also showed a similar distribution in specimens of biliary remnants from just below the portal plate.

Conclusions

Increased expression of CXCR3 associated with a significantly increased CD3 and CD8 T-cell infiltration suggests that CXCR3⁺ lymphocytes in a type 1 (T_H1, T_C1) cytokine milieu may play a role in the pathogenesis of BA.     

Anesthesia for liver transplantation in patients with arterial hypoxemia

Arterial oxygenation during anesthesia and time of postoperative mechanical ventilation were investigated in 17 patients with chronic liver disease who underwent liver transplantation. Six patients had arterial hypoxemia (PaO₂ 64±3 mmHg) and the other 11 patients had normal PaO₂ (105±5 mm Hg) before transplantation. None of the patients were smokers and all had normal preoperative pulmonary X-ray and spirometry. During transplantation, PaO₂ increased in both groups, but PaO₂ was still approximately 20% lower and PA-aO₂ was 40%–60% higher in the hypoxemic group than in the normoxemic patients (P<0.05). The median postoperative time on mechanical ventilation was three times longer in the hypoxemic group (56 h) than in the normoxemic patients (18 h; P=NS). Number or severity of postoperative complications and outcome did not differ between the two groups. It is therefore suggested that patients with arterial hypoxemia without overt lung disease should also be accepted for liver transplantation.     

Partial splenic embolization in patients with liver cirrhosis and hepatocellular carcinoma: Effects on portal hemodynamics

Partial splenic embolization (PSE) was performed on patients with liver cirrhosis to control hypersplenism and gastroesophageal varices. In this study, we evaluated the effects of PSE on the portal hemodynamics and hepatic function of 17 cirrhotic patients with hepatocellular carcinoma. The mean splenic volume and the peak platelet count increased significantly and the splenic vein pressure decreased significantly after PSE. However, the portal blood flow did not change. Changes in the 15-min retention rate of indocyanine green and the arterial ketone body ratio were not significant, but the redox tolerance index increased from 0.24 ± 0.28 × 10^–2 to 0.59 ± 0.35 × 10^–2. These results suggest that PSE may reduce perioperative risks in cirrhotic patients with hepatocellular carcinoma who are candidates for hepatic resection.     

Influence of liver transplantation and cyclosporin on bile secretion —an experimental study in the rat

Bile secretion is reduced after liver transplantation. It has been suggested that this is due either to the effect of cyclosporin or to the damage to the liver graft during preservation and reperfusion. The aim of this study was to explore the influence of cyclosporin as well as of liver transplantation on bile secretion. Bile flow was studied in an experimental model in the rat. In syngeneic liver-transplanted animals, the bile flow was increased compared to the bile flow in the control group (1.29±0.09 ml/h vs 0.66±0.03 ml/h; P<0.01), mainly due to an increased bile acid-independent flow (0.76 ml/h vs 0.50 ml/h; P<0.01). The findings in the livertransplanted rats contrasted with those in a group of nontransplanted animals treated with cyclosporin. Cyclosporin treatment resulted in a reduced bile acid-independent fraction (0.37 ml/h vs 0.50 ml/h, P<0.05) of the bile flow, although no biochemical signs of hepatotoxicity were present. This reduction in the bile acid-independent fraction could, however, not be demonstrated when cyclosporin was given to a group of liver-transplanted rats, although a reduced total bile flow was recorded in the 1st hour measurements. In contrast to previous studies, we found that the cyclosporin vehicle (Cremophor EL), when administered chronically, induced a higher bile flow than that in the control rats. This effect was not seen in the transplanted rats. Our findings in this experimental rat model indicate that cyclosporin will influence and reduce bile secretion and bile acid secretion even if no other signs of liver dysfunction are present. On the other hand, the preservation and reperfusion in this model resulted in an increased bile flow, while bile acid secretion remained constant.     

Adaptive increase of respiratory enzymes in jaundiced patients

A biochemical analysis of mitochondrial metabolism was made on biopsy specimens of fifteen jaundiced patients. In all but three jaundiced patients the phosphorylative activity based on mitochondrial protein was within normal limits or higher. In nine jaundiced patients the concentrations of cytochrome a(+a₃), as representative of respiratory enzymes, increased to more than 1.0 × 10⁻¹⁰ moles/mg protein, as compared with 0.81 of normal mitochondria, and the relative concentrations of cytochromes, flavoproteins and pyridine nucleotides in relation to cytochrome a(+a₃) level remained unchanged. In such patients the phosphorylative activity per unit of cytochrome a(+a₃) decreased to approximately 50 per cent of controls, whereas it was within normal limits or greater in jaundiced patients with cytochrome a(+a₃) less than 1.0 × 10⁻¹⁰ moles/mg protein. It is suggested that respiratory enzyme concentrations increase to compensate for the inhibited phosphorylative activity of respiratory assemblies and to maintain the energy balance in the liver in jaundiced patients.     

Distribution of intrahepatic T, NK and CD3(+)CD56(+)NKT cells alters after liver transplantation: Shift from innate to adaptive immunity?

Background

The liver is an immunological organ containing a large number of T, NK and NKT cells, but little is known about intrahepatic immunity after LTx. Here, we investigated whether the distribution of T, NK and CD3⁺CD56⁺NKT cells is altered in transplanted livers under different circumstances.

Methods

Core biopsies of transplanted livers were stained with antibodies against CD3 and CD56. Several cell populations including T (CD3⁺CD56^-), NK (CD3^-CD56⁺) and NKT cells (CD3⁺CD56⁺) were studied by fluorescence microscopy. Cell numbers were analyzed in relation to the time interval after LTx, immunosuppressive therapy and stage of acute graft rejection (measured with the rejection activity index: RAI) compared to tumor free liver tissue from patients after liver resection due to metastatic disease as control.

Results

Recruitment of CD3⁺CD56⁺NKT cells revealed a significant decrease during high RAI scores in comparison to low and middle RAI scores (RAI 7-9: 0.03 ± 0.01/HPF vs. RAI 4-6: 0.1 ± 0.005/HPF). CD3⁺CD56⁺NKT cells were also lower during immunosuppressive therapy with tacrolimus (0.03 ± 0.01/HPF) than with cyclosporine (0.1 ± 0.003/HPF), cyclosporine/MMF (0.1 ± 0.003/HPF) or sirolimus (0.1 ± 0.01/HPF) treatment. Intrahepatic T cell numbers increased significantly 50 days after LTx compared to control liver tissue (4.5 ± 0.2/HPF vs. 1.9 ± 0.1/HPF). In contrast, NK cells (0.3 ± 0.004/HPF) were significantly fewer in all biopsies after LTx compared to the control (0.7 ± 0.04/HPF).

Conclusions

These data indicate significant alterations in the hepatic recruitment of T, NK and CD3⁺CD56⁺NKT cells after LTx. The increase in T cells and the decrease in NK and CD3⁺CD56⁺NKT cells suggest a shift from innate to adaptive hepatic immunity in the liver graft.