Auxiliary liver transplantation: how to improve regeneration of the native liver by surgery

The technical factors which could influence regeneration of the native liver (NL) in auxiliary liver transplantation (ALT) for fulminant hepatic failure (FHF) are not well known. We studied NL regeneration according to the location of graft anastomosis in the recipient's portal system (superior mesenteric vein versus portal vein), and graft weight (50 % reduced-size versus full-size graft) in a rat model of ALT with 80 % reduction of the NL, and graft arterialization. NL regeneration was significantly more obvious when the graft was anastomosed on the recipient's superior mesenteric vein, thus establishing venous flow to the NL from the pancreas, the spleen, and the stomach, and when a full-size graft was used. The influence of portal venous flow on NL regeneration, assessed by [³H]-thymidine incorporation, was measurable as early as day 2. Both technical variables in combination resulted in significantly greater regeneration (ratio weight of NL/body weight at day 30: 2.32 ± 0.68 % versus 1.21 ± 0.63 % respectively, P = 0.02). Early preservation of portal flow to the NL is advisable to maximize NL regeneration in ALT. In any case, this regeneration is not impeded by the use of large auxiliary grafts. Received: 11 February 1999 Received after revision: 29 July 1999 Accepted: 1 September 1999     

Liver glycogen in fasted rat livers does not improve outcome of liver transplantation

Controversy exists over how the nutritional condition of the donor liver affects transplant outcome. Some studies suggest that livers from fasted animals (liver glycogen-depleted) are more readily injured than livers from fed animals. Our previous study suggested the opposite, i.e., livers from donors fasted for 4 days were significantly more viable on orthotopic liver transplantation. Fasting may decrease the sensitivity of the liver to an inflammatory response or block Kupffer cell activation following transplantation. Thus, long-term fasting may be beneficial for reasons unrelated to liver glycogen content. In this study we attempted to separate out the roles of fasting and liver glycogen in liver transplant outcome by fasting donors for 2 days and then feeding them only glucose to elevate liver glycogen. Rats (Brown Norway) were fed (standard diet), fasted (4 days), or fasted 2 days and then fed glucose (in water) for 2 days. Livers were preserved for either 30 or 44 h in UW solution and transplanted. Four-day fasting of the donor improved the survival rate in liver transplantation (50%–100% in 30-h cold storage, 29%–83% in 44-h cold storage). However, feeding glucose for 2 days to fasted animals caused a decrease in survival in this series of transplants (40% in 30-h cold storage, 0% in 44-h cold storage). In the glucose-fed group, liver glycogen was 240% of that in the control group. This suggests that the presence of a high concentration of liver glycogen is not beneficial to the preserved and transplanted rat liver.     

Warm Carolina rinse solution prevents graft failure from storage injury after orthotopic rat liver transplantation with arterialization

An injury to nonparenchymal cells, characterized by loss of viability of sinusoidal endothelial cells and activation of Kupffer cells, occurs after reperfusion of livers stored for transplantation. Recently, a new solution, Carolina rinse solution, was shown to prevent reperfusion injury to endothelial cells in vitro almost completely and to improve graft survival after orthotopic rat liver transplantation (ORLT) without arterialization. ORLT with arterialization permits longer cold storage of donor livers and more closely models human surgery. Therefore, we evaluated the effects of Carolina rinse solution on graft survival after ORLT with arterialization in syngeneic Lewis rats. Just prior to implantation, donor livers stored in University of Wisconsin (UW) solution were rinsed with 30 ml of Ringer's solution, saline, or Carolina rinse solution at 1°–4°C. In livers stored for 15 h and rinsed with Ringer's or saline solution, long-term graft survival was only 8%. Using Carolina rinse solution containing 1 mmol and 200 mol adenosine per liter, graft survival improved to 40% and 80%, respectively. Graft survival did not improve when using Carolina rinse solution with adenosine omitted or Ringer's solution containing 200 mol adenosine per liter. Livers were also rinsed with Carolina rinse solution containing 200 mol adenosine per liter at 28°–30°C rather than at 1°–4°C. With warm Carolina rinse solution, survival improved further to 100%, 80%, and 50% after 15, 18, and 21 h of storage. After 18 h of storage, light and electron microscopy demonstrated marked denudation of the sinusoidal lining and activation of Kupffer cells in grafts rinsed with Ringer's solution. Use of Carolina rinse solution greatly improved endothelial structure but did not reduce Kupffer cell activation. In conclusion, these findings show that Carolina rinse solution substantially improves graft survival after ORLT with arterialization. Adenosine and warm temperature are important factors contributing to efficacy. A mechanism of protection appears to be prevention of reperfusion-induced endothelial cell injury.     

Effects of warm Carolina rinse on microvascular reperfusion injury in rat liver transplantation

Abstract Recently, it has been demonstrated that the use of both cold Carolina rinse (CR, 4°C) as well as warm Ringer's lactate (RL, 37°C) attenuates microvascular perfusion failure and leukocyte (WBC) accumulation in liver grafts. The aim of this study was to analyse in vivo whether warming of CR can also lead to a reduction in microvascular reperfusion injury in rat liver transplantation. Syngeneic orthotopic liver transplantation, including arterial reconstruction, was performed in male Lewis rats (180–300 g). Livers were stored in University of Wisconsin (UW) solution for 24 h and rinsed with 15 ml CR which was either cold 4 °C ( n = 7) or warm 37 °C ( n = 8) prior to reperfusion. Hepatic microcirculation and WBC accumulation were assessed by intra-vital fluorescence microscopy, and graft function was determined by analysis of bile flow during the 90-min reperfusion period. Warm CR yielded significantly ( P < 0.01) improved sinusoidal perfusion when compared with cold CR; however, the extent of WBC adherence in both sinusoids and postsinusoidal venules did not vary between the groups. In addition, bile flow was slightly increased after warm CR. We conclude that after 24 h of cold storage in UW solution, warming of CR may offer additional benefit in the prevention of microcirculatory reperfusion injury without affecting WBC accumulation.     

Effects of taurine on liver preservation in UW solution with consecutive ischemic rewarming in the isolated perfused rat liver

Taurine (2-aminoethane sulfonic acid) is a physiologic amino acid involved in cellular osmoregulation in various species including man. This study was intended to compare the respective effects of cold storage and consecutive ischemic rewarming of the liver on postischemic hepatic flow and hepatocellular outcome upon reperfusion with or without the addition of taurine to the preservation medium. Livers from male Wistar rats were rinsed free of blood via the portal vein and stored ischemically at 4 °C in UW solution. Livers from group 1 were then rinsed again with 10 ml Ringer's solution and reperfused with Krebs-Henseleit buffer at a constant pressure of 10 mmHg for 45 min at 37 °C in a nonrecirculating manner. Livers from groups 2 and 3 were subjected to 30 min of warm ischemia subsequent to cold storage and prior to reperfusion with 10 mM taurine added to the UW solution in group 3. While there were only very few signs of hepatic injury in group 1, the additional period of warm ischemia (group 2) led to a significant reduction in early perfusate flow and enhanced enzyme leakage from the livers during postischemic rinse and reperfusion. Livers in group 3 exhibited an amelioration in hepatic circulation and significantly reduced enzyme release as compared to group 2. The results clearly demonstrate a remarkable impact of postischemic rewarming on graft viability. Furthermore, the addition of taurine to the preservation medium was shown to improve hepatic circulation and enhance viability of the liver upon reperfusion.     

Protective effect of a prostaglandin oligomer on liver mitochondria in situ: time-shared measurements of fluorescence and reflectance in the cold-preserved rat liver

The protective effect of a new oligomeric derivative of prostaglandin B₂, known as OC-5186, was evaluated using time-sharing spectrofluorometry in the coldpreserved rat liver. Experiments were divided into three groups: in group A, a 5000 ng dose of OC-5186 was administered via the peripheral vein, 1000 ng via the portal vein, and 200 ng/ml in University of Wisconsin (UW) solution; in group B, the OC-5186 dosage was ten times greater than that in group A; in group C (control group), liver procurement and storage were performed without OC-5186. At 0, 12, and 24 h after cold preservation at 4°C, the liver was perfused for 30 min at 12°C with oxygenized Krebs-Henseleit solution, after which the perfusate was switched to deoxygenized Krebs-Henseleit solution. Time sharing spectrofluorometry was used to follow NADH fluorescence at 450 nm with a 360-nm excitation wavelength, as well as the reflectance of cytochrome aa ₃ with 605 minus 620 nm from oxidation to reduction. Rate constants of NADH fluorescence and cytochrome aa ₃ reflectance were used as indices of integrity of the mitochondrial respiratory chain. In group C, the rate constant of NADH fluorescence decreased significantly (P<0.05) from the control value of 8.31±0.21×10^-3 (sec^-1) to 4.97±0.15×10^-3 and 5.58±0.16×10^-3 (mean±SEM) at 12 and 24 h after cold preservation, respectively. By contrast, in groups A and B, the rate constant of NADH fluorescence was maintained at significantly (P<0.05) higher levels of 6.57±0.54×10^-3 and 7.29±0.48×10^-3, and 6.94±0.44×10^-3 and 6.86±0.44×10^-3 at 12 and 24 h, respectively. The rate constant of cytochrome aa ₃ reflectance between the OC-5186 groups and the control group was not significant. It is concluded that OC-5186 has a protective effect on the mitochondrial respiratory chain against cold-preservation and/or reperfusion injury.     

Methyl palmitate prevents Kupffer cell activation and improves survival after orthotopic liver transplantation in the rat

Abstract. The purpose of this study was to determine whetherprevention of Kupffercell activation following orthotopic liver transplantation improves postoperative survival. First, particle phagocytosis by Kupffer cells was monitored continuously from the uptake of colloidal carbon by the perfused liver. Unstored livers took up carbon at rates of around 150 mg/g per hour, whereas storage for 24 h in Euro-Collins solution nearly doubled values to about 290 mg/g per hour. Treatment of rats with methyl palmitate, an inhibitor of phagocytosis by Kupffer cells, reduced carbon uptake to about one-third to one-half of control values in unstored and stored livers, respectively. Oxygen uptake, which was increased about 25% in stored and unstored livers by infusion of colloidal carbon, was only increased 5%-10% in both groups following treatment with methyl palmitate, suggesting that Kupffer cell activation was prevented by methyl palmitate. In livers transplanted after storage for 6 h in Euro-Collins solution (nonsurvival conditions), control rats survived only about 12 h, while treatment with methyl palmitate increased survival time significantly - more than threefold - to about 40 h. These data are consistent with the hypothesis that activation of Kupffer cells following cold ischemic storage and reperfusion is an early event involved in liver graft failure.     

Methyl palmitate prevents Kupffer cell activation and improves survival after orthotopic liver transplantation in the rat

The purpose of this study was to determine whether prevention of Kupffer cell activation following orthotopic liver transplantation improves postoperative survival. First, particle phagocytosis by Kupffer cells was monitored continuously from the uptake of colloidal carbon by the perfused liver. Unstored livers took up carbon at rates of around 150 mg/g per hour, whereas storage for 24 h in Euro-Collins solution nearly doubled values to about 290 mg/g per hour. Treatment of rats with methyl palmitate, an inhibitor of phagocytosis by Kupffer cells, reduced carbon uptake to about one-third to one-half of control values in unstored and stored livers, respectively. Oxygen uptake, which was increased about 25% in stored and unstored livers by infusion of colloidal carbon, was only increased 5%–10% in both groups following treatment with methyl palmitate, suggesting that Kupffer cell activation was prevented by methyl palmitate. In livers transplanted after storage for 6 h in Euro-Collins solution (nonsurvival conditions), control rats survived only about 12 h, while treatment with methyl palmitate increased survival time significantly — more than threefold — to about 40 h. These data are consistent with the hypothesis that activation of Kupffer cells following cold ischemic storage and reperfusion is an early event involved in liver graft failure. Present address: Department of Trauma Surgery, University of Saarland, W-6650 Homburg/S., Federal Republic of Germany     

The impact of liver preservation in HTK and UW solution on microcirculation after liver transplantation

Severe microcirculatory disturbances due to endothelial cell damage and leukocyte adherence during reperfusion of transplanted livers are considered to contribute to early graft failure. Since the degree of reperfusion injury after liver transplantation depends on the length of preservation time and the solution used for preservation, the aim of our study was to assess three solutions with respect to microvascular perfusion and leukocyte adhesion. Therefore, rat livers were stored up to 24 h in Euro-Collins (EC), University of Wisconsin (UW), or histidin-tryphtophan-ketoglutarate (HTK) solutions prior to orthotopic transplantation. The livers were studied in situ 60 min postoperatively using intravital fluorescence video microscopy. Using simple syringe flushing (10 ml), sinusoidal perfusion decreased below 50% in EC preserved livers after 8 h preservation, in HTK preserved livers after 16 h preservation, and remained higher than 70% in livers preserved in UW up to 24 h. Permanent adhesion of leukocytes was increased more rapidly in organs after 1, 8, 16, and 24 h preservation in HTK (16%, 15%, 34%, and 49.7% ± 4.7%) compared to those preserved in UW (15%, 18%, 17%; and 32.7% ± 3.3%; P < 0.05). Using a 10-fold volumn of the organ weight of HTK solution during the harvesting procedure, with an 8 min equilibration period, sinusoidal perfusion (39.6 ± 4.7%) and leukocyte adhesion (42.7 ± 3.1%) were not improved after 24 h. In contrast, equilibration with a volumn of approximately 40-times the liver weight improved sinusoidal perfusion (70.8% ± 2.7%; P < 0.01) and leukocyte adhesion (24.9% ± 3.1%; P < 0.01) significantly. Thus, using HTK solution, simple flushing prior to long-term cold storage resulted in microcirculatory disturbances when compared to UW solution. Larger volumns of HTK solution with an additional equilibration period of 8 min, however, reduced leukocyte adhesion and improved sinusoidal perfusion to a similar degree as UW solution.     

Detrimental effect of sinusoidal overperfusion after liver resection and partial liver transplantation

Abstract Liver resection exposes the remaining sinusoids to an over-proportional blood flow. This mechanism may aggravate ischaemia/ reperfusion damage and rejection in partial liver transplants. We studied the potential relevance of this mechanism for the pathogenesis of partial liver transplant dysfunction. Eighty-four isogeneic Lewis rats were divided into four groups: (I) sham operation; (II) partial liver resection (30% residual liver volume); (III) orthotopic transplantation of a full-size liver; (IV) transplantation of a reduced-size liver (30% transplant volume). Microcirculation was determined by intravital microscopy 90 min after surgery. Survival rates, liver function and morphology were monitored over a period of 14 days. Lowest survival rates and impaired liver function were observed after partial liver transplantation (group IV). These transplants displayed the lowest perfusion rate and an increased rate of leukocyte-endothelium interactions in the presence of a significantly increased sinusoidal blood flow velocity compared with those in groups I and III. Sinusoidal overperfusion in groups II and IV resulted in widespread endothelium lesions. Sinusoidal overperfusion seems to be a significant factor impairing liver function after liver resection. In addition to other adverse factors, such as ischaemia/ reperfusion injury, it can contribute to the pathogenesis of postoperative dysfunction of partial liver transplants.     

Detrimental effect of sinusoidal overperfusion after liver resection and partial liver transplantation

Liver resection exposes the remaining sinusoids to an over-proportional blood flow. This mechanism may aggravate ischaemia/reperfusion damage and rejection in partial liver transplants. We studied the potential relevance of this mechanism for the pathogenesis of partial liver transplant dysfunction. Eighty-four isogeneic Lewis rats were divided into four groups: (I) sham operation; (II) partial liver resection (30% residual liver volume); (III) orthotopic transplantation of a full-size liver; (IV) transplantation of a reduced-size liver (30% transplant volume). Microcirculation was determined by intravital microscopy 90 min after surgery. Survival rates, liver function and morphology were monitored over a period of 14 days. Lowest survival rates and impaired liver function were observed after partial liver transplantation (group IV). These transplants displayed the lowest perfusion rate and an increased rate of leukocyte–endothelium interactions in the presence of a significantly increased sinusoidal blood flow velocity compared with those in groups I and III. Sinusoidal overperfusion in groups II and IV resulted in widespread endothelium lesions. Sinusoidal overperfusion seems to be a significant factor impairing liver function after liver resection. In addition to other adverse factors, such as ischaemia/reperfusion injury, it can contribute to the pathogenesis of postoperative dysfunction of partial liver transplants.     

冷保存对大鼠部分移植肝再生的影响

目的探讨冷保存对大鼠部分肝移植术后肝再生的影响。方法健康SD大鼠分为Ⅰ组（肝切除组）、Ⅱ组（冷保存1h部分肝移植组）和Ⅲ组（冷保存8h部分肝移植组）。观察各实验组生存率，比较各组术后1、6、12、24、48、72、168h肝质量／体质量比率、肝再生率、有丝分裂指数及增殖细胞核抗原表达。结果Ⅰ、Ⅱ、Ⅲ组7d存活率分别为100％、90％、40％；Ⅲ组术后2～3d大鼠肝质量／体质量比率、肝再生率、有丝分裂指数较Ⅰ、Ⅱ组明显偏低（P〈0．05）；Ⅲ组术后12h内增殖细胞核抗原表达较其余两组明显偏低（P〈0．05），48h才达高峰，至第7天阳性表达仍处高水平。结论长时间冷保存降低了部分肝移植术后的肝再生能力和大鼠术后生存率。     

Infections in human liver recipients: different patterns early and late after transplantation

The first 49 consecutive patients who underwent orthotopic liver transplantation between 1984 and 1989 in our department were studied with regard to symptomatic and asymptomatic post-transplantation infections. The major infections carrying a risk of fatal outcome are presented. During the first 4 weeks, fungal and bacterial infections predominated, the percentages of patients affected being 27% and 35%, respectively. Eight patients (17%) suffered from bacterial septicemia, which in six cases was due to gram-negative micro-organisms. The bacterial septicemia was often associated with severe ischemic damage to the graft, rejection, or cholangitis. In addition, a concomitant invasive fungal infection supervened in seven out of eight septic patients, further aggravating the patients' condition. Seventeen of the 49 patients (35%) died after transplantation within 3.3 years. Infection was the cause of death in nine patients (18%), with bacterial septicemia and/or fungemia in eight of these. Cytomegalovirus (CMV) disease was the dominant cause of illness after the 1st month. While only 5 of the 49 patients developed CMV disease during the 1st month (10%), as many as 16 of the 40 recipients who survived beyond that time suffered from symptomatic CMV viremia (40%). CMV mismatching, i.e., the donation of a CMV-positive organ to a CMV-seronegative recipient, entailed the highest risk for CMV disease. Pneumocystis carinii pneumonia occurred within 4 months in 10% of the patients. The four liver recipients affected were among the 20 patients not receiving trimethoprim-sulfamethoxazole prophylaxis. None of the 28 patients who received this prophylaxis over a 12-month period developed this complication (P<0.05). The time-related panorama of infectious complications observed in this study has immediate clinical implications for the screening, prophylaxis, and therapy of infections following liver transplantation.     

Effects of portal vein clamping time on rat liver microcirculation following extended cold preservation and transplantation

Orthotopic rat liver transplantation (ORLT) following extended cold preservation in University of Wisconsin (UW) solution has been shown to induce alterations of the hepatic microcirculation, mainly characterized by areas of no-reflow. The present study was performed to determine whether these alterations were related to the portal vein clamping time (PVCT), shown to be the main determinant of survival after ORLT. The hepatic microcirculation was evaluated using the multiple-indicator dilution curve (MIDC) technique after ORLT following 24-hour cold ischemia in UW solution. Two groups of rats were studied: one with PVCTs of less than 14 min (survival conditions) and one with PVCTs of more than 18 min (nonsurvival conditions). Four hours after ORLT, only long PVCTs were associated with small, but significant, nonperfused areas, about 10 % of the liver not being perfused by water; however, in both survival and nonsurvival conditions, the sinusoidal sieving function was well-maintained in perfused areas. In addition, liver viability parameters and hepatocyte function were similarly and minimally altered. The hepatic microcirculation is minimally altered 4 h after ORLT following extended cold preservation in UW solution, whatever the survival condition. Although only found after long PVCTs, the low magnitude of areas of no-reflow should not be associated with lethal injury of the transplanted liver, a finding further supporting the concept that survival after ORLT following 24-hour cold preservation in UW solution is mainly influenced by extrahepatic factors. Received: 1 December 1998 Received after revision: 6 May 1999 Accepted: 19 July 1999     

The effect of cyclosporin on endothelin levels after orthotopic liver transplantation in rats

To assess the effects of cyclosporin (CyA) on endothelin-1 (ET-1) in rat liver allograft rejection, we evaluated ET-1 expression in samples obtained from BN(RT1ⁿ)-to-BN (group 1) rats, DA(RT1^a)-to-BN (group 2) rats, and DA-to-BN rats treated with 5 mg/kg per day of CyA (group 3). Serum and hepatic ET-1 levels, determined by a radioimmunoassay, remained unchanged in group 1. In group 2, the ET-1 levels peaked on postoperative day (POD) 5 in the liver at 344 ± 31.6 pg/g wet, and on POD 7 in the serum at 38.7 ± 13.1 pg/ml. In group 3, hepatic and renal ET-1 levels showed a progressive increase until POD 10, while serum ET-1 levels remained unchanged. In conclusion, acute rejection caused a temporary increase in the ET-1 level in both the serum and the liver in the early postoperative period what might have been caused by endothelial damage due to ongoing, acute rejection. CyA caused a time-dependent increase in the ET-1 level in both the liver and the kidney without an increase in the serum ET-1 level. The serum ET-1 level might have been affected by the clearance of ET from the liver or kidney. Received: 10 April 1996 Received after revision: 29 October 1996 Accepted: 12 November 1996     

The impact of donor organ quality on postoperative liver function after orthotopic rat liver transplantation

The impact of donor factors for posttransplant liver function was evaluated in the model of orthotopic rearterialized liver transplantation in the rat. The effect of donor fasting, parenteral hyperalimentation, hypotension, warm ischemia and endotoxins on histology, clinical chemistry and MEGX test was analyzed in syngeneic and allogeneic recipients of livers stored for 4 hrs on ice. In syngeneic animals, 20 min of warm ischemia led to significantly elevated serum transaminase levels and degree 2 histological damage on POD 2. Endotoxins produced a grade 1 histological damage. All groups had a lower MEGX formation rate compared to controls. In allogeneic animals, warm ischemia was the single most detrimental parameter. The strength of the rejection response on POD 8 did not depend on the type of donor pretreatment. The major finding of this non-survival study is the deleterious effect of warm ischemia and endotoxin on the functional and structural integrity of liver grafts after 4 hrs of cold ischemia. Received: 9 June 1997     

活体肝部分移植术供肝的处理

目的 探讨活体肝移植术供肝的处理方法。方法 以日本京都大学经治的９例活体肝部分移植供者为对象,对供肝的灌洗时机、方法和供肝的修整及保存等方面进行观察。结果 ９例供肝顺利切取,肝切除量平均占全肝的２０％￣２９％,受肝者存活良好。结论 供肝的灌洗时机、方法和供肝的修整及保存都是活体体肝部分移植术中应重视的问题。     

Comparison of University of Wisconsin (UW) and Eurocollins (EC) preservation solutions in a rat liver transplant model

The Eurocollins (EC) and University of Wisconsin (UW) preservation solutions were compared in a rat liver transplant model. After hepatectomy, 48 rat livers were flushed with either EC or UW preservation solution and were randomly assigned to 1, 12, 24, and 30 h of preservation at 4°C, resulting in eight groups each containing six livers. Following preservation, orthotopic liver transplantation with reconstruction of the hepatic artery was performed. The efficacy of the preservation solution was assessed at 48 h post-transplantation by survival histological features and aspartate transaminase assay (AST) values. None of the rats survived 30 h of liver preservation with EC whereas five out of six rats did with UW preservation. After 24 h of liver preservation, three of the six rats in the EC group survived, compared to all six rats in the UW group. Histological evidence of severe ischemia was found in both groups in all but one survivor (UW, 24 h). After 12 h of EC preservation, one rat died within 48 h and severe ischemic changes were found in the remaining five rats. Among the rats with 12 h of UW preservation, only two out of six showed ischemic changes, and all six rats survived beyond 48 h. Without preservation (1 h), ischemic damage was found in two out of six rats in each group and all rats survived. The median AST values were higher in the EC groups than in the UW groups; the difference became significant after 12-h preservation (EC 900 IU/l versus UW 465 IU/l) and 24-h preservation (EC 5220 IU/l versus UW 631 IU/l). However, the median AST value in the five surviving rats whose livers had been preserved for 30 h in UW climbed to 1880 (950–2240) IU/l.. We conclude that UW solution provides better long-term preservation than EC solution. However, even with UW solution, the observed mortality, the severity of ischemic changes, and the pronounced increase in the median AST value cast doubt upon the safety of liver preservation beyond 24 h.     

Conversion to tacrolimus after liver transplantation

We have reviewed our experience with conversion to tacrolimus after 435 liver transplantations. Tacrolimus was administered as a rescue agent in 33 patients until October 1993. Indications for rescue therapy were: cholestatic forms of severe, steroid-resistant cellular rejection (n=8), OKT3-resistant cellular rejections (n=6), cellular rejections in patients suffering from cyclosporin malabsorption (n=4), late onset cellular rejections (n=4), early chronic rejections (n=3), and chronic vascular or ductopenic rejections (n=8). Response was evident in 29 of the 33 patients (88%), whereas 4 patients (12%) were nonresponsive. Patient and graft survival were 76% and 70%, respecitively. Graft loss with or without patient death occurred in three of eight patients suffering from severe, steroid-resistant cellular rejection, in two of six patients with OKT3-resistant cellular rejections, and in five of eight patients undergoing chronic rejection. In severe steroid-resistant cellular rejection, successful tacrolimus rescue therapy corresponded to a significantly lower total serum bilirubin than unsuccessful therapy (12.0±5.6 mg% vs 29.7±5.9 mg%, P(0.05). We conclude that tacrolimus rescue therapy is a safe and efficient alternative for high-risk cases that do not respond to conservative treatment. In severe, steroid-resistant cellular rejection and in chronic ductopenic rejection, conversion to tacrolimus is beneficial only in a limited number of cases. A predictive parameter, which total serum bilirubin may prove to be in severe, steroid-resistant cellular rejection, is needed to select those cases that might benefit more from retransplantation than from conversion to tacrolimus.     

The characterization of reconstituted passenger leukocytes on the induction of tolerance in rat liver transplantation

The tolerance induced by orthotopic liver transplantation [DA (RT1^a) rats to PVG (RT1^c) rats] can be prevented by total body irradiation of the donor rat. Reconstitution of the irradiated donor with DA splenic leukocytes reintroduces this tolerance. To investigate the major histocompatibility complex (MHC) specificity of passenger leukocytes, irradiated DA donors were reconstituted by third-party BN (RT1ⁿ) splenic leukocytes. The reconstitution with BN splenocytes re-established DA-specific tolerance in PVG recipients, as confirmed by subsequent DA cardiac allografting, while BN hearts were rejected with second-set tempo. To determine which cell components play an important role in re-establishing liver graft tolerance, DA splenic leukocytes were further purified into three types: T, B, and adherent cells. Only “T-cell-enriched” preparations restored liver graft tolerance in three out of five PVG recipients. These results suggest that passenger leukocytes of differing MHC types can help to induce liver-specific tolerance and that T cells in the liver graft may be essential to regulate tolerance induction. Received: 31 December 1996 Received after revision: 14 April 1997 Accepted: 15 April 1997