Creation of porcine liver tumor using human hepatoma cell lines: experimental study

BACKGROUND

Pig is an ideal animal to study the efficacy of surgical and ablative treatment options available for the treatment of liver tumors. But there is no liver tumor model available in pig. This experiment was carried out to create liver tumors in the pig using immunosuppression and portal tolerance.

MATERIAL AND METHODS

Two mini pigs (specific pathogen free) were immunosupressed using cyclosporine, azathioprine and prednisolone immunotherapy. Human hepatoma cell line (HepG2) was delivered into the liver through portal vein injection. Engraftment of the tumor cell was monitored using regular measurement of serum alfa- fetoprotein level (AFP). Pigs were sacrificed at the end of six weeks to confirm any evidence of tumor in the liver.

RESULT

Although there was rise in serum AFP level in the first week, tumor cells did not engraft in the liver and there was no evidence of liver tumor at the end of experiment.

CONCLUSION

Effect of immunosuppression and portal tolerance does not prevent rejection of human hepatoma cells by porcine immune system.

How to improve the quality of kidneys from non-heart-beating donors: a randomised controlled trial of thrombolysis in non-heart-beating donors

BACKGROUND

The growth in the prevalence of end-stage renal failure has been accompanied with a rise in the waiting list for renal transplantation, which has not been matched by an increase in the kidney donor pool. Non-heart-beating donors (NHBD) offer a potential source of kidneys that are not currently being significantly used. Cardiac arrest for a protracted period of time leads to in situ thrombosis, and, as a consequence, the discard rates for harvested kidneys is higher than brain-stem-dead donors.

METHODS

A double-blinded, randomised, controlled trial of streptokinase preflush or placebo for NHBD was performed. An initial 30 donors were entered into the study. After routine nephrectomy, NHBD kidneys were machine perfused as part of viability screening before transplantation. Kidneys were then transplanted within 24 hours of cardiac arrest. The primary objectives were the improvements of viability parameters (perfusion, enzyme levels, and histopathology) of the kidneys. The secondary objective was to increase the number of kidneys passing the viability tests and thus transplanted.

RESULTS

The two groups of NHBD donors and their kidneys were similar in their descriptive epidemiologic characteristics. The NHBD kidneys from the streptokinase-treated donors had a better appearance at procurement (P<0.001) and performed better during machine preservation (P<0.001). Enzyme biomarkers present in the kidney perfusate were all significantly reduced by the use of streptokinase. These included glutathione S-transferase (P<0.001), fatty acid binding protein (P<0.001), and alanine aminopeptidase (P<0.001). However, although there was a higher proportion of kidneys transplanted through the use of streptokinase (63.6% with streptokinase vs. 42.6% with placebo), this did not achieve significance. There was no difference with respect to postoperative bleeding and transfusion requirements in the recipient whether streptokinase preflush or placebo was used.

CONCLUSION

This study using streptokinase preflush in the NHBD was found to improve the condition of the kidneys retrieved. The improvement in the quality of the donor kidneys was not associated with an increased morbidity in the recipient.

Reperfusion injury in renal transplantation: comparison of LD, HBD and NHBD renal transplants

Comparison of reperfusion injury in kidneys transplanted from LD, HBD or NHBD donors is presented in the paper. Central venous blood samples (taken during perioperative period) was assessed for free radicals, total antioxidant activity and various markers of tissue injury. There was demonstrable ischemia reperfusion injury occurring at the time of revascularization, which was particularly notable in kidneys transplanted from NHBD donors.

Do tissue damage biomarkers used to assess machine-perfused NHBD kidneys predict long-term renal function post-transplant?

BACKGROUND

Renal transplantation in many units is limited by the availability of donor organs. Kidneys obtained from non-heart-beating donors (NHBD) represent an important resource, with the potential to substantially increase the available donor organ pool. Such kidneys are associated with increased warm ischaemic tissue injury which may be assessed by hypothermic machine perfusion. Within our transplant centre, a key component of such damage assessment and viability screening involves the quantification of the tissue damage biomarkers glutathione S-transferase in kidney perfusates.

METHODS

Since 1998, 126 NHBD kidneys were machine-perfused prior to implantation, resulting in 74 transplants. Kidney perfusate samples were assayed for glutathione S-transferase in "real time", and alanine aminopeptidase and fatty acid binding protein in "retrospect".

RESULTS

The pre-transplant concentration of these tissue injury biomarkers determined pre-transplant did not correlate with subsequent longer-term renal function, as assessed by measurement of serum creatinine (tGST: Spearman correlation r=-0.02; Ala-AP: r=0.02; H-FABP: r=-0.05) and creatinine clearance (tGST: r=0.08; Ala-AP: r=-0.02; H-FABP: r=0.14) for those kidneys that had passed their viability tests.

CONCLUSIONS

Thus whilst these biomarkers may represent reliable pre-transplant indicators of immediate kidney viability and short-term kidney function, they do not predict the efficacy of renal function in the longer term.

Long-term renal function in kidneys from non-heart-beating donors: A single-center experience

BACKGROUND

Cadaveric kidneys from brain-stem-dead donors continue to be limited because the number of donors has reached a plateau. Wide recruitment of non-heart-beating donors (NHBD) could significantly increase the donor pool. NHBD renal transplants are underused because of the concern of poor quality graft function from such donors. In response to this perception, we reviewed 46 NHBD renal transplants performed in our center since 1998.

METHODS

All NHBD kidneys were machine-perfused using the Newcastle continuous-hypothermic pulsatile preservation system before transplantation. A control heart-beating-donor (HBD) group was taken as the next consecutive HBD renal transplant to the NHBD transplant. The outcome and quality of function of the groups of renal transplants were analyzed for short-term and long-term performance.

RESULTS

The renal transplant patients were matched for donor and recipient factors. Survival rates for allografts and patients were similar for 1 to 3 years. There was an increased incidence of delayed graft function in the NHBD renal transplants in the perioperative period. The creatinine clearance was 22.8+/-2.3 mL/minute for NHBD patients and 44.4+/-2.9 mL/minute for HBD patients at the time of discharge from hospital. This difference equalized after 3 months and the creatinine clearance for NHBD was 44.2+/-2.4 mL/minute and for HBD 49.2+/-3.4 mL/minute.

CONCLUSIONS

Our results for NHBD renal transplants confirm that such grafts suffer primary warm ischemic injury, shown by the increased incidence of acute tubular necrosis and consequent delayed graft function. This produced poor renal function at the time of hospital discharge. After 3 months, the renal function of NHBD cases improved to the level seen in HBD patients.

Early results of a non-heartbeating donor (NHBD) programme with machine perfusion

Freeman Hospital, Newcastle upon Tyne restarted their non-heartbeating donor (NHBD) programme in September 1998 using machine perfusion, due to early poor results with conventional cold storage (45% graft survival, phase II). Since then, 15 NHBD kidneys have been transplanted. The retrieval protocol consisted of in situ perfusion with a double balloon triple lumen cannula in Maastricht category II male donors age range 13-59 years. Mean primary warm ischaemic time was 24.8 min (range 10-44). All kidneys were machine perfused through a locally developed perfusion system. The viability was assessed by serial measurements of total GST (maximum acceptable limit of 200 units/l) and intrarenal vascular resistance (IRVR) was recorded. Fifteen of the 22 kidneys (68.62%) were transplanted. Delayed graft function (DGF) was seen in ten recipients (66.6%), two kidneys had immediate function (IF), one organ was exported, two recipients died of unrelated causes and a further seven kidneys were discarded (two had high tGST, two were infected and three had poor flow characteristics). In phase III, a success rate of 91.7% was thus achieved, which was better than the phase II period (P = 0.027, Fisher 2-tail test). Machine perfusion has been successfully introduced in phase III to the Newcastle NHBD programme and facilitates viability assessment of NHBD kidneys.

The impact of cytomegalovirus serology for 7-year graft survival in cadaveric kidney transplantation--the Newcastle experience

To analyse the contribution of cytomegalovirus (CMV) serology to long-term graft survival in cadaveric kidney transplantation, 404 transplants from a single centre were divided into four subgroups with respect to the combination of donor and recipient CMV antibody status. Graft survival was estimated according to Kaplan-Meier for 1, 3, 5 and 7 years post-transplantation. The single-centre results confirm a negative impact of CMV-positive donor organs for initial graft survival in CMV-negative recipients within the first 3 years after transplantation. However, when 5- and 7-year long-term graft survival was studied, Donor +/Recipient - pairs showed a favourable long-term result, whilst D +/R - pairs had surprisingly a poorer outcome. Therefore, the concept of avoiding transplantation in the D +/R + CMV serology group should be ignored whereas attempts could be made to improve the poor long-term outcome of D +/R + pairs or to reduce its size by organ allocation.

Comparison of proteolytic enzymes and glutathione S-transferase levels in non-heart-beating donors' (NHBD) kidney perfusates

In order to identify biochemical markers of kidney damage prior to transplantation, we determined the levels of activity of a range of proteolytic enzymes in kidney perfusate samples from non-heart-beating donor (NHBD) cases. Urinary protease activities have been described as indices of kidney damage in renal disease; their potential as markers of tissue damage in kidneys before transplantation has not been assessed. In an attempt to identify additional/improved biochemical markers, the present study compared the levels of total glutathione S-transferase (GST) with corresponding levels of several proteolytic enzymes in perfusate fluid from machine perfused NHBD kidneys. Proteases were selected to represent factors that may influence enzyme efflux, such as intracellular localization or molecular size.

METHODS

Perfusate samples were obtained over an 8-hour period from machine-preserved NHBD kidneys. Protease activities in these samples were determined by fluorometric assays and comparison made with total GST activity. Individual proteases were analysed in the transplanted and non-transplanted kidney groups (discarded on the basis of other viability parameters).

RESULTS

A correlation between protease activity and total GST was obtained for only leucyl- and pyroglutamyl aminopeptidase. Furthermore, in the transplanted group, it was possible to set nominal upper limits of activity for alanyl-arginyl- and dipeptidyl IV-aminopeptidase (AP). In the non-transplanted kidney group protease levels were increased above "normal" upper limits for the same enzyme types. By the use of alanyl AP it was possible to discriminate 75% of unsuitable kidneys discarded by the use of other criteria.

CONCLUSION

The lack of correlation between total GST and protease activity for most of the enzymes investigated and alanyl AP levels in perfusate samples could be related to differences in cellular localisation, suggesting that assays of alanyl AP may give complimentary biochemical information relating to kidney tissue damage. Quantification of alanyl AP in machine perfusate samples may be a valuable additional independent biomarker of tissue damage.

Assessment of non-heart-beating donor (NHBD) kidneys for viability on machine perfusion

The shortage of organs has resulted in renewed interest in organs from non-heart-beating donors (NHBD). Viability assessment of such organs may reduce the incidence of delayed graft function and primary non-function. In Phase III of the NHBD programme, introduction of machine perfusion enabled the assessment of these marginal donors. Since then the graft survival has been 88.4% compared with the previous phase where machine perfusion or viability assessment was not done (45.5%). The parameters used were total glutathione S-transferase (GST) in the perfusate, the intrarenal vascular resistance (IRVR) and flow characteristics over time.

METHODS

All NHBD kidneys were machine perfused through a locally developed perfusion system. The viability was assessed by serial measurements of the above-mentioned parameters.

RESULTS

Forty-two local NHBD kidneys were retrieved and one kidney was imported, of which 19 donors (i.e. 38 kidneys) were of the uncontrolled (category II) donors. After viability assessment on machine perfusion; two kidneys were discarded due to positive tests for syphilis, four kidneys had high total GST levels, five kidneys due to high IRVR and poor flow characteristics and one did not flush on retrieval. Three kidneys were exported after viability tests. In 28 NHBD kidney recipients, immediate graft function was seen in two kidneys, 22 (84.6%) developed delayed graft function. One kidney had primary non-function, and two recipients lost their grafts, due to chronic rejection and renal vein thrombosis. There were two deaths, unrelated to transplantation. Graft survival was achieved in 88.4% (23/26 graft survival in phase III) of cases.

CONCLUSION

Machine perfusion and assessment of NHBD kidneys has been successfully introduced to the Newcastle NHBD programme. This approach, using renal transplants from largely category II donors produced a success rate of 88.4% which was significantly better than the phase II period (45.5%) of the program (p=0.023, Fisher 2 tail test).

The relevance of donor T cell-directed immunoglobulin G in historic sera in the age of flow cytometry

BACKGROUND

Renal transplant recipients with a positive historic cross-match due to donor T cell-directed IgG antibodies are considered to have decreased graft survival, even if their current serum is negative prior to transplantation. With the use of flow cytometric cross-match for testing current sera, false-negative results could be eliminated and the outcome of transplantation in this group of patients could be improved, assuming that immunological memory is effectively controlled with immunosuppression.

METHODS

We reviewed our records to identify those patients who underwent cadaveric renal transplant, with a historic IgG positive cytotoxic T cell cross-match and a current negative flow cytometric T cell cross-match.

RESULTS

Eighteen patients underwent cadaveric renal transplant in the face of a historic IgG positive T cell cross-match and a current negative flow cytometric T cell cross-match. In 14 patients treated with cyclosporine-based immunosuppression the 1-, 2-, and 3-year cumulative graft survival rates were 57, 50, and 43%, respectively. Ten of the 14 patients (71%) ultimately lost their grafts.

CONCLUSIONS

Even with negative flow cytometric cross-match in current serum, a positive historic conventional cross-match suggests a high risk of graft failure.

Extending the indications for curative liver resection by portal vein embolization

AIMS: The aim of ipsilateral portal vein embolization is to induce hypertrophy of normal tissue when resection of a cancerous portion of the liver is contraindicated only by the volume of liver that would remain following surgery. This study reports its use in primary and metastatic liver tumours. METHODS: Eight patients with inoperable liver tumours (three women and five men of median age 68. 5 years; three colorectal hepatic metastases, two cholangiocarcinomas and three hepatocellular cancers) were selected for portal vein embolization. Selected portal branches were occluded distally with microbeads and proximally with coils. Liver volumes were determined by magnetic resonance imaging before embolization and again before surgery, 6-8 weeks later. RESULTS: Embolization was performed successfully in seven patients by the percutaneous-transhepatic route; one further patient required an open cannulation of the inferior mesenteric vein. Management was altered in six patients, who proceeded to 'curative' surgery. The projected remaining (predominantly left lobe) liver volumes increased significantly from a median of 350 to 550 ml (P < 0.05, Wilcoxon matched pairs test). Two patients had disease progression such that surgery was no longer indicated. One patient, whose disease progressed, had the left portal branch occluded unintentionally by a misplaced coil that was successfully retrieved, although the left portal branch remained occluded. CONCLUSIONS: Portal vein embolization produced significant hypertrophy of the normal liver and extended the option of 'curative' surgery to six of the eight patients in whom it was attempted. It appears to be equally effective for primary and metastatic liver tumours in selected patients.

Intravenous bisphosphonate prevents symptomatic osteoporotic vertebral collapse in patients after liver transplantation

Osteoporosis is common in patients with chronic cholestatic liver disease, and atraumatic spinal fracture is a recognized complication after orthotopic liver transplantation. Bisphosphonates are potent inhibitors of osteoclast bone resorption and have been successfully used to treat postmenopausal osteoporosis. We examined whether preoperative bone mineral density can predict the risk of fracture after orthotopic liver transplantation and whether intravenous bisphosphonate can prevent fractures in high-risk patients. Beginning in February 1993, standard bone mineral density measurements of the lumbar spine were performed as part of routine pretransplantation assessment. On the basis of a preliminary analysis from January 1995, patients with a lumbar spine bone mineral density of <0.84 g/cm2, or <84% of the predicted value (age/sex), were treated with intravenous bisphosphonate (pamidronate disodium) every 3 months before and for 9 months after liver transplantation. Bone mineral density measurements were available in 90 of 136 consecutive first transplants performed in our unit from February 1993 to September 1996. Before the use of pamidronate, 7 patients sustained symptomatic vertebral fractures. Their mean spine bone mineral density was lower than in the 38 patients with no clinical evidence of fracture (81.8% +/- 12.3% v 94.2% +/- 10.2%; P = .006). Since the introduction of pamidronate, no symptomatic vertebral fractures have occurred. Of 29 surviving patients with bone mineral density <0.84 g/cm2 before transplantation, 38% who did not receive treatment with pamidronate suffered spontaneous fracture, whereas 0 of 13 who received treatment suffered such a complication. A low lumbar spine bone mineral density is associated with a high risk of symptomatic vertebral fracture after liver transplantation. These results suggest that this risk is considerably reduced by the administration of intravenous bisphosphonate before and after transplantation.

Sequential coronary artery bypass grafting and orthotopic liver transplantation: a case report

We report a case of combined coronary artery by-pass grafting and orthotopic liver transplantation on cardiopulmonary bypass, in a 56-yr-old man with rapidly progressive ischaemic heart disease and end-stage liver disease. Three months after surgery he is asymptomatic with normal liver function.