Ethical perspectives about organ allocation for transplantation.

The ethical questions suggested by the allocation of organs for transplantation can be assembled around the notion of justice. It is a domain of health care in which there is a chronic lack of resources, but for patients whose life is at stake, sometimes at short term. It has similarities with the triage, imposed in some conditions of emergency medicine, at war or during civil catastrophes. The question will be approached from the points of view of the main stakeholders.

Hypodermin A, a new inhibitor of human complement for the prevention of xenogeneic hyperacute rejection.

BACKGROUND: Hyperacute rejection (HAR) of discordant xenografts in the pig-to-human combination can be prevented using tranplants expressing transgenic molecules that inhibit human complement. Hypodermin A (HA), a serine esterase that degrades C3, was tested in the guinea-pig-to-rat and in the pig-to-human combinations. METHODS: Hypodermin A was tested in vitro, ex vivo, and in vivo models of HAR in the guinea-pig-to-rat combination. Hamster ovary cells (CHO) and a line of porcine aortic endothelial cells (PAEC11) were transfected with HA complementary DNA (cDNA). RESULTS: The pattern of degradation of rat and human C3 by HA was different (multiple bands lower than 40 kDa) from the physiologic pattern observed after spontaneous degradation of rat C3 or physiologic activation of human C3. The CH50 activity in serum was significantly lower in rats treated with 3.2 mg HA/kg than in untreated rats (45 +/- 16 U/ml vs. 700 +/- 63 U/ml, P < 0.05). Sera from rats injected with 3.2 mg/kg of HA were less effective in lysing guinea-pig endothelial cells (12 +/- 7%) than normal rat sera (79 +/- 3%; P < 0.001). Ex vivo, guinea-pig hearts perfused by rat serum supplemented with HA survived longer than those perfused by non-treated serum (210 +/- 34 and 154 +/- 71 min, respectively; P < 0.05). In vivo, guinea-pig hearts transplanted into HA treated rats survived longer than in non-treated rats (27 +/- 5 min vs. 13 +/- 4 min; P < 0.001). In the presence of human serum, smaller amounts of C6 and C5b-9 were deposited onto HA-transfected CHO cells than onto control cells. The mHA-PAEC11 cells were significantly more resistant to lysis by human C than control PAEC11 cells. CONCLUSIONS: These data suggest that transgenic HA could be used to prevent hyperacute xenogeneic rejection.

[Medical and economic evaluation of organ transplantation in France. The example of liver transplantation]. / L'évaluation médico-économique des greffes d'organe en France. L'exemple de la transplantation hépatique.

BACKGROUND: Organ transplantation is an expensive and risky medical procedure. Estimating the cost is difficult because the care is complex and involves many actors. We present a methodological framework for the economic evaluation of organ transplantation in France which include a detailed collection of all the direct costs and the simultaneous analysis of health status. It was applied to evaluate the cost of liver transplantation in France. METHODS: All consecutive adults transplanted or placed on the waiting list of liver transplantation in the Department of Surgery of Cochin Hospital, Paris, between 1994 and 1996 were included. All resource use was measured during one year: staff wages, pharmacy and blood, laboratory and radiology, supplies, overhead hospital services. Mean quality of life was estimated by the survival weighted by the Karnofsky index. RESULTS: Transplantation: 38 patients were included. The first year mean cost after transplantation was 561,000FF (included rehospitalizations cost of 120,000FF). Care outside the hospital induced 10% of the total cost. Mean quality of life was 63% (from 0% to 93%) and increased with time, whereas cost decreased. Waiting list: 26 of 33 patients on waiting list were transplanted. The first year mean cost was 95,000FF (included 32,000FF for first evaluation) and increased with time. 44% of cost was supported by another hospital than the transplanting one. Sickness allowance added 20% to the cost. The mean quality of life was 56% during the first year. CONCLUSIONS: This complete approach of organ transplantation cost respected the medical procedure over the time. Detailed costs take into account the care outside the hospital. This method can be used in other countries and generalised to all surgical or medical procedure as heavy as the organ transplantation.

Randomized trial of choledochocholedochostomy with or without a T tube in orthotopic liver transplantation.

OBJECTIVE: To compare the incidence of biliary complications after liver transplantation in patients undergoing choledochocholedochostomy reconstruction with or without T tube in a multicenter, prospective, randomized trial. SUMMARY BACKGROUND DATA: Several reports have suggested that biliary anastomosis without a T tube is a safe method of biliary reconstruction that could avoid complications related to the use of T tubes. No large prospective randomized trial has so far been published to compare the two techniques. METHODS: One hundred eighty recipients of orthotopic liver transplantation were randomly assigned to choledochocholedochostomy with (n = 90) or without (n = 90) a T tube in six French liver transplantation centers. All types of biliary complications were taken into account. RESULTS: The overall biliary complication rate was increased in the T-tube group, even though these complications did not lead to an increase in surgical or radiologic therapeutic procedures. The major significant complication was cholangitis in the T-tube group; this did not occur in the other group. The incidence of biliary fistula was 10% in the T-tube group and 2.2% in the group without a T tube. Other biliary complications were similar. The complication rate of cholangiography performed with the T tube was greater than with other types of biliary exploration. The graft and patient survival rates were similar in the two groups. CONCLUSION: This study is the first large prospective, randomized trial of biliary complications with or without a T tube. The authors found an increase in the biliary complication rate in the T-tube group, which was linked to minor complications. The T tube did not provide a safer access to the biliary tree compared with the others types of biliary explorations. The authors recommend the performance of choledochocholedochostomy without a T tube in liver transplantation.

[A new model of isolated perfused heart. Study of hypodermin A in hyperacute xenograft rejection]. / Mise au point d'un modèle de coeur isolé perfusé. Application à l'étude de l'hypodermine A dans la prévention du rejet suraigu xénogénique.

AIMS OF THE STUDY: Isolated perfused heart (IPH) system and heart transplantation in the guinea-pig/rat combination represent a good model for the study of hyperacute xenograft rejection (HAR) in which the component plays a central role. Hypodermin A (HA), a protease cleaving the component, could be used to delay the HAR. METHODS: Creation of an original IPH working with rat serum (30 mL) and ex vivo study of HAR and I'HA. RESULTS: Study of HAR is possible with this IPH system. The mean guinea-pig heart survival after perfusion by normal rat serum was 38 +/- 7 min and was lower than survival observed after perfusion by guinea-pig serum (210 +/- 34 min) (p < 0.001), by decomplemented rat serum (177 +/- 45 min) (p < 0.001), and by rat serum with 20 micrograms/mL of HA (154 +/- 71 min) (p < 0.001). CONCLUSION: We developed an original system of isolated perfused heart allowing ex vivo study of HAR. HA delayed the occurrence of the HAR and confirmed the central role of the component in the HAR.

Efficient suicide gene therapy of transduced and distant untransduced ovary tumors is correlated with significant increase of intratumoral T and NK cells.

Gene therapy using herpes simplex type 1 thymidine kinase gene (HSV1-TK) transfer followed by ganciclovir (GCV) treatment has revealed an important intratumoral and regional bystander effect that is at least partly immune-mediated. The aim of this work was to study the modifications of T lymphocyte subpopulations in a model of distant bystander effect occurring between ovary tumors. Bilateral ovarian tumors were generated in 21 WKY rats by injection in the ovarian pouch of either parental or HSV1-TK-expressing DWA-OC-1 ovarian cancer cells. After 14 days, rats were treated for two weeks with GCV (75 mg/kg x 2/d) or saline. All rats were killed at day 29 for pathological examination. The tumor-infiltrating mononuclear cells were analyzed by semi-quantitative immunohistochemistry. As compared to rats receiving saline, GCV-treated animals exhibited a complete disappearance of the HSV1-TK+ tumors with residual fibrotic scars (ovary weights: 0.46 +/- 0.4 g vs 10.11 +/- 1.5 g, P < 0.001). Interestingly, the contralateral HSV1-TK negative tumor showed a significant regression (12.39 +/- 1.93 g vs 22.24 +/- 237 g, P < 0.014). Furthermore, a lower incidence of tumoral ascitis was found in the GCV-receiving group (20% vs 90% P < 0.02). Within both TK- and TK+ tumors, there was a significant increase of CD4+, CD8+ and NK cells in the GCV-treated group compared to the saline-treated group. This study thus indicates that a distant bystander effect not only acts between close tumors within a given organ such as the liver, but also between more distant tumors in the peritoneal cavity. This effect is associated with significant infiltration of the tumor by immune system cells, supporting the notion that the distant bystander effect is immune-mediated.

A preclinical model of hepatocyte gene transfer: the in vivo, in situ perfused rat liver.

Delivering retroviruses targeted to hepatocytes in vivo involves the injection of retroviruses directly into the portal vein. The aim of this work was to establish a clinically relevant system for retrovirus-mediated gene transfer in a new model of in vivo, in situ perfused rat liver and to study the transgene expression. At 24 h after partial hepatectomy, the liver was completely excluded from the splanchnic circulation using an extracorporeal shunt. Two independent normothermal, oxygenated perfusion systems were used. First, liver perfusion was carried out with a recirculating system (1 h). Culture supernatant containing retroviruses (1.5 x 10(8) ffu/ml, beta-galactosidase gene) was used as perfusate. Then the liver perfusion was maintained for more 30 min in a single liver passage system using culture medium without retroviruses as perfusate. High hepatocyte transduction rates (up to 34.4%) were obtained. PCR analysis showed no provirus in extrahepatic organs. Viral titrations performed simultaneously (inflow and outflow liver lines) showed that after 1 h of perfusion (up to 30 successive liver passages) retroviruses were still detected in the liver outflow perfusate (up to 2.0 x 10(7) ffu/ml). Washing the liver for 30 min dramatically decreased the leakage of retroviruses in the outflow. In order to be of clinical use, the injection of retroviruses targeted to hepatocytes in vivo should be done while the liver is completely excluded from the splanchnic circulation to avoid any extrahepatic retrovirus diffusion.

Defective interleukin-1 receptor antagonist production is associated with resistance of acute liver graft rejection to steroid therapy.

Thirty percent of acute liver graft rejection episodes are resistant to steroids. As interleukin-1 (IL-1) is an important target of steroid therapy, we examined the possible involvement of reduced sensitivity of IL-1 production to steroids or defective production of its antagonist, IL-1Ra. Patients were assessed during steroid-sensitive or -resistant rejection and 2 years later. In situ IL-1beta and IL-1Ra expression was evaluated by immunohistochemistry; their production was assayed by enzyme-linked immunosorbent assay and the gene polymorphisms by reverse transcriptase-polymerase chain reaction on blood cells. Hepatic IL-1beta and IL-1Ra expression were enhanced during rejection. IL-1 production and its inhibition by steroids were similar in steroid-responsive and steroid-resistant rejection. However, IL-1Ra production was lower in steroid-resistant than in steroid-responsive rejection, and this difference was still observed 2 years after rejection. IL-1beta and IL-1Ra gene polymorphisms did not differ between patients with and without steroid resistance. Low IL-1Ra production is associated with steroid resistance of acute rejection and is due to a constitutional defect. The early identification of such patients might qualify them for stronger anti-rejection therapy, including IL-1Ra.