Interleukin-15 receptor blockade in non-human primate kidney transplantation.

BACKGROUND: Interleukin (IL)-15 is a chemotactic factor to T cells. It induces proliferation and promotes survival of activated T cells. IL-15 receptor blockade in mouse cardiac and islet allotransplant models has led to long-term engraftment and a regulatory T-cell environment. This study investigated the efficacy of IL-15 receptor blockade using Mut-IL-15/Fc in an outbred non-human primate model of renal allotransplantation. METHODS: Male cynomolgus macaque donor-recipient pairs were selected based on ABO typing, major histocompatibility complex class I typing, and carboxy-fluorescein diacetate succinimidyl ester-based mixed lymphocyte responses. Once animals were assigned to one of six treatment groups, they underwent renal transplantation and bilateral native nephrectomy. Serum creatinine level was monitored twice weekly and as indicated, and protocol biopsies were performed. Rejection was defined as a increase in serum creatinine to 1.5 mg/dL or higher and was confirmed histologically. Complete blood counts and flow cytometric analyses were performed periodically posttransplant; pharmacokinetic parameters of Mut-IL-15/Fc were assessed. RESULTS: Compared with control animals, Mut-IL-15/Fc-treated animals did not demonstrate increased graft survival despite adequate serum levels of Mut-IL-15/Fc. Flow cytometric analysis of white blood cell subgroups demonstrated a decrease in CD8 T-cell and natural killer cell numbers, although this did not reach statistical significance. Interestingly, two animals receiving Mut-IL-15/Fc developed infectious complications, but no infection was seen in control animals. Renal pathology varied widely. CONCLUSIONS: Peritransplant IL-15 receptor blockade does not prolong allograft survival in non-human primate renal transplantation; however, it reduces the number of CD8 T cells and natural killer cells in the peripheral blood.

Development of the right colon and the peritoneal surface during the human fetal period: human ontogeny of the right colon.

BACKGROUND: Development of the digestive tract during the human fetal period has been the subject of many studies, but there are no works that study the ontogeny of both the right colon and the peritoneum. METHODS: Based on the dissections of adult male cadavers and human fetuses, the aim of this anatomical study was to demonstrate the rules of the morpho-functional group, consisting of the right colon and its peritoneum surface, in human ontogeny. RESULTS: The morphology of the right colon results from a rotational motion, inducting the migration of the cecum in the right iliac fossa and formation of the hepatic flexure. This intestinal migration is based on the axis of rotation of the spreading area of the colon at the ventral side of the lower pole of the right kidney, which becomes visible after the 17th week. CONCLUSION: Our different observations plead in favor of the peritoneal fusion theory. A few variations of this fusion can explain all the disorders in the position of the cecum-appendix that are encountered in current surgery, as well as the possibility of internal hernias.

Nonhuman primate infections after organ transplantation.

Nonhuman primates, primarily rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), and baboons (Papio spp.), have been used extensively in research models of solid organ transplantation, mainly because the nonhuman primate (NHP) immune system closely resembles that of the human. Nonhuman primates are also frequently the model of choice for preclinical testing of new immunosuppressive strategies. But the management of post-transplant nonhuman primates is complex, because it often involves multiple immunosuppressive agents, many of which are new and have unknown effects. Additionally, the resulting immunosuppression carries a risk of infectious complications, which are challenging to diagnose. Last, because of the natural tendency of animals to hide signs of weakness, infectious complications may not be obvious until the animal becomes severely ill. For these reasons the diagnosis of infectious complications is difficult among post-transplant NHPs. Because most nonhuman primate studies in organ transplantation are quite small, there are only a few published reports concerning infections after transplantation in nonhuman primates. Based on our survey of these reports, the incidence of infection in NHP transplant models is 14%. The majority of reports suggest that many of these infections are due to reactivation of viruses endemic to the primate species, such as cytomegalovirus (CMV), polyomavirus, and Epstein-Barr virus (EBV)-related infections. In this review, we address the epidemiology, pathogenesis, role of prophylaxis, clinical presentation, and treatment of infectious complications after solid organ transplantation in nonhuman primates.

The role of intraoperative parathyroid hormone testing in patients with tertiary hyperparathyroidism after renal transplantation.

BACKGROUND: Intraoperative parathyroid hormone (PTH) testing has been shown to accurately define adequacy of parathyroid resection in patients with primary hyperparathyroidism (HPT) and alters the operative management in 10% to 15% of cases. However, the benefit of this technique in patients with tertiary HPT after renal transplantation undergoing parathyroidectomy is unclear. METHODS: Intraoperative PTH was measured in 32 consecutive patients undergoing parathyroidectomy for tertiary HPT after renal transplantation between March 2001 and November 2004 by using the Elecsys assay at baseline and, subsequently, 5, 10, and 15 minutes after curative resection. The outcomes of these patients were evaluated. RESULTS: All patients were cured after surgery. Of the 32 patients, 29 were found to have parathyroid hyperplasia, while 1 had a single adenoma and 2 had double adenomas. The average drop in intraoperative PTH levels after curative resection was 69 +/- 3.5% at 5 min., 77 +/- 2.3% at 10 minutes, and 83 +/- 3.4% at 15 minutes. PTH testing changed the intraoperative management in 5 (16%) patients. One patient with a single adenoma and 2 patients with double adenomas had a >50% drop at 10 minutes. after excision; therefore, the operation was terminated without further resection. Two patients did not have a >50% drop at 10 minutes after 3.5 gland resection. These patients were explored further, and additional supernumerary parathyroid glands were identified and resected. After resection of these additional glands, the PTH fell by >50%, indicating cure. CONCLUSIONS: In patients undergoing parathyroidectomy for tertiary HPT after renal transplantation, a decrease in intraoperative PTH levels >50% at 10 minutes after completion of the operation indicated adequate resection. Furthermore, intraoperative PTH testing altered the operative management in 16% of patients. Therefore, similar to its role in patients with primary HPT, intraoperative PTH testing appears to play an equally important role in the management of patients with tertiary HPT undergoing parathyroidectomy.

Two-dose daclizumab induction therapy in 209 liver transplants: a single-center analysis.

BACKGROUND: Patient and graft survival after liver transplantation are adversely affected by early posttransplant renal dysfunction. Therefore, our immunosuppressive strategies should be as "renal sparing" as possible. This is the largest published series to date using daclizumab induction therapy in a renal-sparing regimen. METHODS: This is a retrospective, nonrandomized study comparing 209 adult liver transplants with daclizumab induction to 115 transplants with no induction. RESULTS: Patient and graft survival were similar, despite higher pretransplant acuity of illness and older age in the induction group. Acute rejection within the first 6 months occurred less commonly in the induction group (25.4% vs. 39.1%, P=0.01), despite significantly delayed initiation and lower doses of a calcineurin inhibitor. Mycophenolate mofetil was used more commonly in induction patients, but the efficacy of daclizumab in preventing rejection was independent of this. Patients with a pretransplant creatinine concentration 1.5 mg/dL or less had less rejection if they received induction. Renal function worsened in noninduction patients but showed sustained improvement throughout follow-up in induction patients with a pretransplant creatinine concentration greater than 1.5 mg/dL. Induction therapy provided better rejection prophylaxis among those requiring temporary calcineurin inhibitor cessation because of renal dysfunction. The incidences of histologic hepatitis C recurrence and cytomegalovirus infection were similar in each group. CONCLUSIONS: Liver recipients with and without pretransplant renal dysfunction have less acute rejection with daclizumab induction therapy. This is not associated with an increased risk of over-immunosuppression. Sustained renal improvement in recipients with pretransplant renal dysfunction is possible with daclizumab induction.

Factors associated with (un)willingness to be an organ donor: importance of public exposure and knowledge.

BACKGROUND: Transplantation is increasingly limited by the supply of donor organs. Identifying subgroups that do not support organ donation will allow targeted efforts to increase organ donation. METHODS: A total of 185 non-acutely ill outpatients visiting a community physician's office voluntarily completed a survey designed to capture views and general knowledge/misconceptions about cadaveric organ donation/transplantation. RESULTS: Of 185 patients, 86 were willing to donate, 42 were unwilling, and 57 were unsure. Willingness to donate was significantly associated with: having discussed the topic with family; having known a cadaveric organ donor; age 55 yr; having graduated high school; recognizing the organ shortage as the primary problem in transplantation; having received a post-high school degree; having seen public information within 30 d; and having a family member in health care (all p

Use of preserved vascular homografts in liver transplantation: hepatic artery aneurysms and other complications.

Hepatic artery aneurysms/pseudoaneurysms (HAAs) are rare but serious complications after orthotopic liver transplantation (OLT). Revascularization should accompany aneurysmectomy if possible and is more feasible if the aneurysm presents late after transplantation. The optimal conduits for revascularization in this situation are not known. Two patients with hepatic artery aneurysms/pseudoaneurysms who had aneurysmectomy and revascularization with third-party cadaveric iliac arterial grafts 1 and 4 years after OLT are presented in detail, with an emphasis on the preservation method used for the grafts. Both livers were successfully revascularized with arterial grafts preserved for 21 and 26 days after procurement. Hepatic patency was documented in both 5 and 6 months after repair; graft function has remained normal 13 and 32 months after repair. Third-party vessels preserved for shorter periods have been used successfully in four other situations, including living-donor liver transplantation, and are briefly discussed. In conclusion, properly preserved vascular homografts are useful in LT for purposes other than initial vascular reconstruction. They also provide an excellent vascular conduit in recipients of livers from other (possibly living) donors.