Circulating xanthine oxidase and neutrophil activation during human liver transplantation

BACKGROUND & AIMS

Oxygen free radicals, generated by xanthine oxidase (XO) and activated leukocytes, are involved in reperfusion injury in experimental liver transplantation. The roles of XO and neutrophil activation during reperfusion in clinical liver transplantation were studied.

METHODS

In 10 patients undergoing liver transplantation, we assessed plasma concentrations of circulating XO by enzyme-linked immunosorbent assay (ELISA), the purine metabolites hypoxanthine, xanthine, and urate by high-performance liquid chromatography, lactoferrin by ELISA, and malondialdehyde fluorometrically up to 48 hours postoperatively.

RESULTS

During reperfusion after portal vein declamping, elevated plasma concentrations of XO (52.1 ng/mL [range, 8.0-440.1]), hypoxanthine (81.62 micromol/L [48.2-108.7]), xanthine (21.01 micromol/L [8.7-22.3]), and lactoferrin (532.6 ng/mL [370.4-1326.6]) were observed compared with the preoperative levels (0 ng/mL [0-12], 1.88 micromol/L [0.62-3.15], 0.95 micromol/L [0-0.41], and 164.3 ng/mL [73.7-334.1], respectively; all P < 0.05). No changes occurred in urate or malondialdehyde. After portal vein declamping, XO, hypoxanthine, and xanthine levels were substantially greater in the hepatic than portal vein (all P < 0.05). Marginal transhepatic differences occurred in lactoferrin.

CONCLUSIONS

Reperfusion during liver transplantation is associated with liberation of xanthine oxidase, hypoxanthine, and xanthine from the liver into the circulation. During reperfusion, intravascular neutrophil activation takes place in the hepatic circulation.

Cytomegalovirus infection is associated with increased inflammation and severe bile duct damage in rat liver allografts

It has been suggested that cytomegalovirus (CMV) infection is involved in allograft rejection. In liver transplantation, it has been suggested that CMV is associated with the development of vanishing bile duct syndrome (VBDS), and persistent CMV has been found in liver grafts that develop chronic rejection. In this experimental study, the effect of rat CMV (RCMV) infection on intragraft changes was investigated in a rat model of acute liver allograft rejection. Liver transplantations were performed in a rat strain combination of PVG (RT1c) --> BN (RT1n). No immunosuppression was given. One group of animals was infected with RCMV Maastricht Strain (10(5) plaque-forming units, intraperitoneally), and another group was left uninfected. The grafts were examined histologically after the rats were killed on postoperative days 7 through 9 at the early phase and days 20 through 30 at the late phase of rejection. Immunohistochemical studies were performed to demonstrate the immunological activation markers major histocompatibility complex class II and interleukin 2 receptors, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and their ligands. RCMV infection was demonstrated from the grafts by culture and direct antigen detection. In liver allografts undergoing acute rejection, CMV significantly increased portal inflammation and caused more severe bile duct damage than in the uninfected grafts. CMV was also linked to the induction of VCAM-1 in the endothelial cells. The ongoing infection was found to vary over time in the different structures of the liver grafts, including the vascular endothelium and bile ducts. Our results support an association between CMV infection and the immunological mechanisms of rejection, as well as the role of CMV in the development of bile duct damage in liver allografts.

Human herpesvirus-6 infection after liver transplantation

A diagnosis of posttransplantation human herpesvirus-6 (HHV-6) infection was established for eight adult recipients among a liver transplantation patient population of 121. The diagnosis was based on serology and demonstration of HHV-6 specific antigens in liver biopsy specimens with use of monoclonal antibodies and immunoperoxidase staining. A significant graft dysfunction was recorded in association with serodiagnosis. HHV-6 early antigens, as well as HHV-6 variant B antigens, were detected retrospectively in all six available liver biopsy specimens. Histologic examination of biopsy specimens demonstrated acute rejection in 5 of the 8 patients, and 3 patients had portal lymphocyte infiltration. In five cases cytomegalovirus (CMV) infection was associated with HHV-6 infection; in four cases CMV antigens were also detected in the biopsy specimens. Two patients who had pure HHV-6 infection without CMV infection or rejection had significantly impaired graft function, with a positive antigen-detection test. Thus, HHV-6 may infect the liver allograft and cause graft dysfunction and may possibly be associated with rejection and/or CMV infection.

Bile duct bacterial isolates in primary sclerosing cholangitis: a study of explanted livers

BACKGROUND/AIMS

The pathogenesis of the inflammatory lesion in primary sclerosing cholangitis is unknown. The clinical picture is characterized by i.a. episodes of fever, the cause of which also remains speculative. Previous studies of bacterial isolates in the liver or bile ducts in primary sclerosing cholangitis have had the shortcoming of possible contamination associated with the sampling. The aim of this study was to investigate whether bile and bile duct tissue, obtained under sterile conditions in connection with liver transplantation, contain bacteria.

METHODS

We studied bile from bile duct walls and bile collected from the explanted livers of 36 patients with primary sclerosing cholangitis and 14 patients with primary biliary cirrhosis.

RESULTS

Positive cultures were obtained from 21 of 36 primary sclerosing cholangitis patients, but from none of the primary biliary cirrhosis patients. The number of bacterial strains was inversely related to the time after the last endoscopic retrograde cholangiography. Treatment with antibiotics or intraductal stent, or the occurrence of fever before liver transplantation did not seem to influence the culture results, whereas antibiotic treatment in connection with endoscopic retrograde cholangiography may possibly have reduced the number of isolates in the cultures. Alpha-haemolytic Streptococci were retrieved as late as 4 years after the last endoscopic retrograde cholangiography. Retrospective analysis of liver laboratory tests after endoscopic retrograde cholangiography did not indicate a deleterious effect of the investigation.

CONCLUSIONS

The data suggest that antibiotics should be given routinely in connection with endoscopic retrograde cholangiography. They also raise the question of a possible role of alpha-haemolytic Streptococci in the progression of primary sclerosing cholangitis.

Organ exchange in the Nordic countries

Scandiatransplant is an organ exchange organisation founded in 1969. It serves a population of 23 million inhabitants in the five Nordic countries; Iceland, Norway, Sweden, Finland and Denmark. Scandiatransplant maintains a common central waiting list for all Nordic patients waiting for necro-organ transplantation. The waiting lists are maintained on a central computer by each of the eleven transplant centres in the organisation. The number of necro-organ donors in Scandiatransplant is about 340-375 yearly, corresponding to 15-16 donors per million population (PMP) per year. Since the foundation, a total of 14,500 necro-kidney transplants have been performed, and the number of transplants with extrarenal organs is steadily increasing. Presently, about 7-8 liver transplants PMP are being performed, and the heart transplant activity amounts to about 5 PMP. The supreme authority of Scandiatransplant is the Council of Representatives, in which each transplant centre is represented by one or more professionals who are clinically active in organ transplantation. The responsibility for day-to-day operations lies with the Board which has one member appointed by each of the five Nordic countries and a chairman elected by the Council. The activities of Scandiatransplant are financed exclusively by the participating centres.

Scandiatransplant: organ transplantation in the Nordic countries 1996

The Nordic collaboration in organ transplantation was initiated nearly 30 years ago in the frame of Scandiatransplant. With a recent formalization of its structure, Scandiatransplant has become a modern organ exchange organization. The increasing activities of Scandiatransplant clearly reflect the continuously growing need for a close and firm Nordic collaboration in the transplantation field, for the benefit of the numerous patients waiting for an organ transplant.

Pharmacokinetics and ventilatory effects of oxycodone before and after liver transplantation

The pharmacokinetics and ventilatory effects of oxycodone were studied in six volunteer patients with end-stage liver cirrhosis before and after orthotopic liver transplantation. Plasma samples and urine were collected for 24 hours after intravenous administration of 0.05 mg/kg oxycodone hydrochloride. Concentrations of oxycodone and its metabolites, noroxycodone and oxymorphone, were measured in plasma and urine. THe median elimination half-life of oxycodone was 13.9 hours (range, 4.6 to 24.4 hours) in patients with cirrhosis before transplantation and 3.4 hours (range, 2.6 to 5.1 hours) after transplantation (p < 0.05). Correspondingly, oxycodone clearance increased from 0.26 L/min (range, 0.15 to 0.73 L/min) before transplantation to 1.13 L/min (range, 0.71 to 3.98 L/min) after transplantation (p < 0.05). Oxycodone depressed ventilation more strongly before transplantation than after transplantation (p < 0.05). Care should be exercised when oxycodone is used in patients with end-stage disease.

Manipulation of alcohol drinking by liver transplantation

The procedure of liver transplantation in alcoholic liver disease raises the question whether it would be possible to regulate the recipient's future drinking by the choice of donor liver. To address this question, we conducted transplantations with rat lines selected for high (AA) and low (ANA) alcohol preference. AA recipients having alcohol experience before the operation remained heavy drinkers regardless of whether the graft came from an AA or ANA donor. However, in these AA recipients who started drinking only after the operation, differences emerged, with AA grafts creating heavy drinking and ANA donor livers resulting in very low drinking. An overall increase in the acetaldehyde levels was introduced by the ANA livers, thus reflecting the original line differences. Similarly, in subsequent experiments, it was observed that when the aldehyde dehydrogenase inhibitor calcium carbimide was introduced in different amounts to the diet, alcohol drinking was reduced more in animals not used to drinking. The magnitude of this effect, especially in situations with established heavy drinking, is of relevance in future contemplations about liver transplantations between humans with different aldehyde dehydrogenase genotypes.

Dopexamine improves liver oxygenation during crystalloid resuscitation from experimental hemorrhagic shock

OBJECTIVE

To evaluate the effects of dopexamine administration on hemodynamic variables and tissue oxygen tensions during crystalloid resuscitation from hemorrhagic shock.

DESIGN

Randomized, control trial.

SETTING

An animal laboratory at a university center.

SUBJECTS

Twelve piglets, mean weight 22 kg.

INTERVENTIONS

The animals were anesthetized and bled to a state of hemorrhagic shock and resuscitated, using a crystalloid solution infused at a rate of approximately 2.6 mL/min/kg (total amount 208 mL/kg). Cardiac output and mean arterial pressure (MAP were measured as indicators of volume filling during the 20- to 30-min resuscitation period and during the follow-up period until 80 mins from the start of resuscitation. Dopexamine was administered by infusion at 6 micrograms/kg-min from the start of volume replacement (dopexamine group, n = 6). The rest of the animals (control group, n = 6) were given volume replacement only.

MEASUREMENTS AND MAIN RESULTS

Systemic oxygen transport variables were calculated. Tissue oxygen tensions were continuously recorded from the liver, conjunctival layer, and via subcutaneous and transcutaneous electrodes in the abdominal region. MAP decreased from 119 +/- 2 (SEM) to 44 +/- 2 mm Hg and cardiac output decreased by 77% during the shock period. During resuscitation, cardiac output was restored in both groups. MAP increased close to the baseline during the early resuscitation period and decreased slowly during follow-up. Oxygen delivery remained at 46% of baseline, whereas systemic oxygen consumption was restored during resuscitation in both groups. Liver tissue oxygen tension increased well above baseline during resuscitation in the dopexamine group, and liver tissue oxygen tension was significantly higher than in the control group. After 60 mins of resuscitation, the liver oxygen tension decreased to control group values. None of the other tissue oxygen tensions showed any differences between groups.

CONCLUSIONS

Dopexamine administration during crystalloid resuscitation from hemorrhagic shock was well tolerated and resulted in significant and specific, although transient, improvement in liver oxygenation.

Expression of adhesion molecules and their ligands in liver allografts during cytomegalovirus (CMV) infection and acute rejection

Vascular adhesion molecules and their ligands are important in leukocyte-endothelial cell interactions and in T-cell activation of rejection cascade. Also, cytomegalovirus (CMV) infection is suggested to be involved in the mechanisms of rejection. In this study, the expression of vascular adhesion molecules ICAM-1, VCAM-1 and ELAM-1 in the liver allografts, the number of leukocytes positive for their ligands LFA-1, VLA-4 and SLex, and activation markers (class II, IL2-receptor) were investigated in liver allografts during CMV infection and acute rejection and compared to grafts with normal function and histology. The adhesion molecules, their ligands and activation markers were demonstrated from liver biopsy frozen sections by the immunoperoxidase technique and monoclonal antibodies. A significant induction of ICAM-1 and VCAM-1 was seen in vascular and sinusoidal endothelium associated with both CMV and rejection, and induction of ELAM-1 in vascular endothelium in rejection only. In both cases, the number of leukocytes expressing LFA-1 was significantly increased, but VLA-4-positive cells were more characteristic for CMV and SLex-positive cells more for rejection. IL2-receptor positivity was practically seen in rejection only, but class II-expressing cells were increased during both CMV infection and rejection. In conclusion, adhesion molecules were induced and the infiltrating cells expressed their ligands both in liver rejection and during CMV infection, although the expression pattern was slightly different.

Poor prognosis of gallbladder cancer persists regardless of improved diagnostic methods. Incidence and results of surgery during 20 years in Helsinki

BACKGROUND AND AIMS

The ominous prognosis of primary gallbladder cancer is well-known. This study assesses whether the prognosis has improved, and whether the substantial development in the radiologic imaging techniques is reflected in the survival of these patients.

MATERIAL AND METHODS

The series consisted of 122 patients operated on for primary cancer in the gallbladder in the Helsinki City area between 1970 and 1990.

RESULTS

The mean age of the patients was 68.6 years and did not change during the period, but there was a significant proportional increase in male patients. Only 2% of patients had a localized disease at the time of diagnosis, and there was no improvement in the diagnostic sensitivity during the observation period. Yet, the number of unexpected postoperative cancer diagnoses increased from 4% to 15% during the two decades. The primary mortality decreased from 21% to 13%, the one-year survival increased from 7% to 13%, whereas the five-year survival remained unchanged.

CONCLUSIONS

During the past two decades the frequency of surgery for primary gallbladder cancer has increased significantly among males in the Helsinki City area. Regardless of the improved immediate survival the long-term survival has remained poor. The marked development in radiologic techniques is not reflected in the prognosis of these patients. Even under conditions in which the potential for the diagnosis of a malignant gallbladder disease is available, the opportunities for radical surgery are not utilized maximally, which is a cause for concern.

Persistent cytomegalovirus in liver allografts with chronic rejection

Cytomegalovirus (CMV) infection is one of the suggested risk factors for chronic allograft rejection. Clinical and experimental studies have shown that CMV is somehow implicated in rejection mechanisms and in the generation of graft arteriosclerosis, characteristic of chronic rejection. In liver transplantation, there is also evidence of an association between CMV and vanishing bile duct-syndrome (VBDS), which is characteristic of chronic liver allograft rejection. In this study, the role of posttransplant CMV infection and of acute rejection in the patients with irreversible, histologically confirmed chronic liver rejection with VBDS and vasculopathy was analyzed. Ten of 200 (5%) consecutive liver transplants were lost due to chronic rejection, from between 5 and 28 months from transplantation. In these 10 patients, acute rejections were frequent, and nine of ten patients had at least one episode of rejection early after transplantation. All patients (10 of 10) had a history of CMV infection usually following acute rejection. To investigate the role of CMV in chronic rejection, nine available removed grafts were examined for the presence of the CMV genome by DNA-hybridization in situ using a biotinylated CMV-DNA probe. Persistent CMV-DNA was found in all of those available grafts with chronic rejection. CMV-DNA was strongly expressed in the remaining bile ducts and moderately expressed in the endothelial cells of the vascular structures, the CMV positivity of hepatocytes varied from graft to graft. Thus, persistent CMV genome was found in those structures that are the major targets of the chronic rejection process in the liver. These findings support the previous suggestion of an association between CMV and chronic allograft rejection.

Persistent cytomegalovirus in liver allografts with chronic rejection

Cytomegalovirus (CMV) infection is one of the suggested risk factors for chronic allograft rejection. Clinical and experimental studies have shown that CMV is somehow implicated in rejection mechanisms and in the generation of graft arteriosclerosis, characteristic of chronic rejection. In liver transplantation, there is also evidence of an association between CMV and vanishing bile duct-syndrome (VBDS), which is characteristic of chronic liver allograft rejection. In this study, the role of posttransplant CMV infection and of acute rejection in the patients with irreversible, histologically confirmed chronic liver rejection with VBDS and vasculopathy was analyzed. Ten of 200 (5%) consecutive liver transplants were lost due to chronic rejection, from between 5 and 28 months from transplantation. In these 10 patients, acute rejections were frequent, and nine of ten patients had at least one episode of rejection early after transplantation. All patients (10 of 10) had a history of CMV infection usually following acute rejection. To investigate the role of CMV in chronic rejection, nine available removed grafts were examined for the presence of the CMV genome by DNA-hybridization in situ using a biotinylated CMV-DNA probe. Persistent CMV-DNA was found in all of those available grafts with chronic rejection. CMV-DNA was strongly expressed in the remaining bile ducts and moderately expressed in the endothelial cells of the vascular structures, the CMV positivity of hepatocytes varied from graft to graft. Thus, persistent CMV genome was found in those structures that are the major targets of the chronic rejection process in the liver. These findings support the previous suggestion of an association between CMV and chronic allograft rejection.

A rat model of monitoring liver allograft rejection

Rat models are often used to study liver allograft rejection. We have established a model for rat liver allograft rejection, monitored by fine needle aspiration biopsy (FNAB), in the strain combination PVG-to-BN with a mean survival time of 37 +/- 20 days. In this model, we observed acute rejection with an intense peak of lymphoid blasts and lymphocyte-dominated inflammation in the FNAB [9.1 +/- 3.0 corrected increment units (CIU)], and an eventual increase in macrophages (up to 4.2 +/- 4.4 CIU), together with fibrosis and parenchymal necrosis in the graft. Markers of immune activation, such as an increase in IL-2-receptor (from 1% +/- 2% to 21% +/- 13%) and class II (from 20% +/- 9% to 43% +/- 13%) expressing lymphoid cells and induction of ICAM-1 in the graft, were consistent with the overall cellular response. The FNAB correlated well with parallel graft histology. In this rat model, the atraumatic monitoring makes a close follow-up possible without having to sacrifice the experimental animals. This saves work, animals, and costs in the study of liver rejection.

Cardiac evaluation of liver transplant recipients: QT dispersion in electrocardiogram

Increased QT dispersion, the interlead variability of the QT interval length in the 12-lead electrocardiogram, reflects uneven ventricular repolarization as a sign of cardiomyopathy. We analyzed QT dispersion in the preoperative electrocardiogram of 100 adult liver transplant recipients and 20 healthy control subjects. In 12% of the liver recipients, QT dispersion was increased above 65 ms (mean + 3SD). Six of these patients had a liver storage disease (haemochromatosis, Wilson's disease or amyloidosis). Five had a history of cardiac disease. Severe intraoperative cardiac complications occurred in three patients with markedly increased QT dispersion (> or = 99 ms). In conclusion, in liver storage diseases the heart may be affected, leading to increased risk of cardiac complications, which might be predicted from increased QT dispersion. Analysis of QT dispersion, a noninvasive inexpensive technique, can be recommended to be included in the cardiac screening of liver transplant candidates.