Results with combined kidney and paratopic segmental-pancreas transplantation.

Rehabilitation and quality of life after combined pancreas and kidney transplantation was assessed in 15 previously diabetic patients in renal failure and compared with 11 diabetic patients in renal failure transplanted with a kidney only. The paratopic segmental-pancreas-grafting technique, which allows physiologic insulin delivery into the portal venous system, was used in 13 patients; 2 patients received a heterotopic segmental-pancreas graft, resulting in systemic insulin delivery. A kidney was transplanted heterotopically in all cases. Mean age, duration of diabetes, retinopathy, neuropathy, mortality, infection rate, and immunosuppressive treatment did not differ significantly between the groups. Diabetic patients with only kidney transplants had difficulties adjusting to their diabetes, which may be partly due to the immunosuppressive treatment. The quality of life only marginally improved. In contrast, patients with a combined pancreas-kidney graft achieved full rehabilitation within a short time.

Pregnancy after combined pancreas-kidney transplantation.

Four successful cases of pregnancy after combined pancreas-kidney transplantation at four different centers are summarized. The techniques used for the pancreas transplantations were duct obstruction in one patient and enteric exocrine diversion in two patients; in all three patients the insulin delivery was to the systemic circulation. In one patient exocrine diversion was to the stomach and the vascular anastomosis to the splenic vessels, thus accomplishing portal insulin delivery. Immunosuppression consisted of cyclosporin and prednisolone in two patients; cyclosporin alone in one patient; and cyclosporin, azathioprine, and prednisolone in one patient. In all a cesarean section was performed, due to deteriorating renal function in two patients, a fall in fetal growth in one patient, and fear of inducing pancreas-graft pancreatitis during normal delivery in one patient. In all four women, perfect metabolic control was retained throughout the pregnancy, and despite the proximity of the pancreas graft to the growing uterus in three of the women, the pancreas grafts did not suffer any damage during the pregnancy. However, in one patient the pancreas graft was lost in acute rejection after delivery. This pancreas had functioned normally for 3 yr before this occasion. Of the offspring, one was completely normal, one had a bilateral cataract, and two were small for date. The latter two subsequently showed normal growth development. At follow-up at 3, 5, 7, and 28 mo, all kidney grafts and three of the pancreas grafts remained functional. We conclude that after combined pancreas-kidney transplantation, successful conception and pregnancy can be obtained. Despite reduced islet mass (segmental grafts), normal metabolic control can be retained throughout the pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Tolerance of porcine renal allografts induced by donor spleen cells and seven days' treatment with cyclosporine.

Liver allografts in pigs and in rats elicit a substantial cellular immune response that can resolve spontaneously with the induction of donor-specific systemic tolerance. Self-limiting interactions between host and donor (graft)-derived leukocytes may be the basis for tolerogenesis. We have attempted to reproduce this effect of liver grafting in pigs by peroperative infusion of donor leukocytes into kidney graft recipients given an interrupted short course of CsA designed to promote donor leukocyte survival and interaction with host cells. This protocol can secure long-term kidney graft survival resistant to challenge by donor skin grafting. Donor skin is, however, rejected, but more slowly than third-party skin, indicating a degree of systemic specific unresponsiveness in these long-term kidney graft recipients.

[Isogenic islet transplantation on the rat liver (method for isolation and purification of the Langerhans islets)]. / Transplante isogênico de ilhotas de Langerhans no fígado de ratos. (Metodologia para separação e purificação das ilhotas de Langerhans).

The major indication for pancreas or islet transplantation is diabetes mellitus type I. This process has to supply the insulin necessity keeping glucose under control. We have studied isogenic islet transplantation on the rat (WAG-RT1u) liver. The method of isolation and purification of the islets obtained 2.834 +/- 551.64 islets with purity of 83 +/- 2.45%. Diabetes was induced by streptozotocin and seric glucose prior transplantation was 35 mmol/L. The islet transplantation of 2.834 +/- 551.64 islets in the rat liver has normalized glucose test from 9.62 +/- 2.65 mmol/L 10 days after transplantation to 7.43 +/- 0.27 mmol/L later in the follow-up (P < 0.05). The median survival time of the islets was 73 days. In conclusion both the method of isolation and purification of the islets and islet transplantation was effective in the control of the diabetes induced by streptozotocin with median survival time of both islet and rat more than 73 days when rats were sacrified.

Pancreatic transplantation: the Cambridge experience.

In contrast to heterotopic pancreas transplantation and conventional insulin therapy the paratopic positioning of a segmental pancreas graft provides physiological endocrine hormone delivery into the portal venous circulation. Metabolic studies performed on previously insulin dependent diabetic patients with renal failure with functioning paratopic pancreas transplants and heterotopic kidney grafts from the same donor showed near normal day to day glucose control with normal fasting glucose levels and normal HbA1 values. Hyperinsulinaemia was not seen in these patients. The effect of denervation of the pancreatic graft on the entero-insular axis and its influence on the islets were investigated. The incretin effect was preserved indicating a significant hormonal stimulation of the entero-insular axis.

Distribution and persistence of antigen-presenting cells after intrathymic injection.

Intrathymic injection of donor immune cells has been shown by previous studies to prolong survival of rat allogeneic tissues. The aim of this pilot study was to assess the distribution and the persistence of intrathymically (i.t.) injected purified antigen presenting cells (APC) over a period of time in the rat model DA-to-WAG (RT1av to RT1u) using a specific monoclonal antibody (Mab) with RT1Aa class I polymorphic specificity (R3/13 clone). Purified non-parenchymal cells (NPC) or dendritic cells (DC) were prepared from liver and spleen of DA rats with a purity of greater than 60% and 90%, respectively, shown by selected Mab staining methods. DA NPC (1 x 10(6)) or DC (5 x 10(5)) in 20 microl were injected into both lobes of the thymus of WAG rats with or without 1 ml antilymphocyte serum (ALS) intraperitoneally. Thymus tissue was removed on days 3, 5, 10, 20 and 30, and processed for frozen sections and immunohistochemical staining with R3/13. Numerous DA-positive cells were detected in the first 3-10 days post-i.t. inoculation in both NPC- and DC-treated rats, with or without ALS. After day 10, the proportion of positive cells decreased in all cases except in rats given NPC and ALS, where similar numbers of R3/13-positive cells were seen throughout. These DA-positive cells were mostly found in the medullary portion of the thymus at the corticomedullary junction in close proximity to thymic dendritic interdigitating cells. We concluded from this pilot study that the injected cells remained in the thymus for a limited period. However, the immunosuppressive effect of ALS promoted some degree of persistence of donor APC in the thymus beyond 30 days. Further studies are in progress to reveal the specificity of these cells.

Studies of the entero-insular axis following pancreas transplantation in man: neural or hormonal control?

To study the role of hormonal and neural factors in the control of the entero-insular axis the insulin, C-peptide, and glucose-dependent insulinotropic peptide (GIP) responses to oral and intravenous glucose were investigated in 5 patients who had received a combined kidney and paratopic pancreas transplant, with physiological portal venous drainage. The incremental areas under the insulin and C-peptide responses to oral glucose were significantly greater than the responses to intravenous glucose (insulin: patients 7983 +/- 1937 (+/- SE) vs 3513 +/- 2188 mU l-1 min, p less than 0.002, control subjects 5505 +/- 1035 vs 1066 +/- 484 mU l-1 min, p less than 0.004; C peptide: patients 440 +/- 80 vs 144 +/- 61 nmol l-1 min, p less than 0.01, control subjects 200 +/- 38 vs 63 +/- 16 nmol l-1 min, P less than 0.01). The incretin effects for insulin (patients 4.4 +/- 1.4, control subjects 7.7 +/- 1.8) and C-peptide (patients 4.4 +/- 0.9, control subjects 3.7 +/- 0.9) and the GIP responses to oral and intravenous glucose were not significantly different between transplant patients and control subjects. As the incretin effect was preserved, despite a denervated pancreas, hormonal rather than neural factors may be more important in mediating increased insulin secretion after oral carbohydrate. The normal GIP response is compatible with its proposed role as an insulinotropic hormone.

Does intrathymic injection of alloantigen-presenting cells before islet allo-transplantation prolong graft survival?

Current immunosuppressive agents have potentially dangerous side-effects, are non-specific and most are also diabetogenic. We investigated tolerance induction with intrathymic injection of purified antigen-presenting cells (APC) plus a single dose of antilymphocyte serum (ALS) intraperitoneally before allogeneic islet transplantation in the rat model WAG to Lewis (RT1u to RT1l). Purified donor APC [non-parenchymal cells (NPC) or dendritic cells (DC)] were prepared from liver and spleen, respectively. Isograft function for more than 120 days proved that islet isolation, purification and transplantation procedures were adequate. A total of WAG DC (4 x 10(5)) or NPC (2 x 10(6)) in 20 microl were injected into both lobes of the thymus of 140-210 g Lewis recipients followed by a single injection of ALS. Three days later, diabetes was induced with streptozotocin (60 mg/kg). Four days later allogeneic islets were grafted into the liver by intraportal injection of 3000 WAG islets. Control animals (n = 8) received 20 microl saline intrathymically instead of APC. Graft function was assessed by blood glucose measurements with glucose levels above 15 mmol/l on 3 consecutive days defined as graft rejection. Animals given DC (n = 9) or NPC (n = 8) intrathymically plus 1 ml of ALS, rejected their grafts in an accelerated fashion with a median survival time (MST) of 3 days. However, control animals rejected their grafts with a MST of 7 days, but with two animals surviving for more than 2 months. In conclusion, intrathymic inoculation with purified APC plus a single dose of ALS did not prolong allogeneic islet graft function but induced accelerated rejection of the islet allografts.