The influence of organ acceptance criteria on long-term graft survival: outcomes of a kidney transplant program.

BACKGROUND: In an effort to improve our transplant program's dead-donor kidney acceptance criteria, we compared 2 different consecutive time periods in our transplant program. Period I, in which the program used more-restrictive criteria in accepting dead-donor kidneys for our patients, and period II, when the program used less-restrictive criteria for the dead-donor kidneys that were accepted. The less-restrictive criteria resulted in an increase in the number of renal transplants performed. METHODS: A retrospective database analysis was performed of all organ-donor offers to a single kidney transplant program from July 1, 2004, to September 30, 2006 (period I = July 1, 2004, through July 10, 2005, and period II = July 11, 2005 through September 30, 2006). Kidney acceptance rates were compared between 2 consecutive time periods during which the program used different organ acceptance criteria. Data analysis included a comparison of donor characteristics, reason for organ refusal, creatinine clearance, and graft survival. Graft survival was obtained for both kidneys associated with each offer, even if 1 or both of the organs were transplanted at a different center. RESULTS: Donor age and kidney quality were the most common reasons for refusal during both transplant periods. The organ acceptance rate improved markedly during period II. There was a marked increase in the number of kidney transplants performed during a 12-month period when comparing the 2 periods: 16 transplants during period I versus 46 transplants during period II. Graft survival was not significantly different between the 2 periods. Calculated creatinine clearance, which we used as a marker of organ quality, was statistically lower during period II. CONCLUSIONS: Increased acceptance rate was not associated with statistically significant decreased graft survival. Although an increase in delayed graft function was associated with broader acceptance criteria, this factor did not affect overall graft survival. By increasing our kidney acceptance rate, we were able to successfully transplant more patients.

Long-term comparative outcomes between 2 common ureteroneocystostomy techniques for renal transplantation.

PURPOSE: We compared the incidence of ureteral complications between the classic (Lich-Gregoir) technique and the recently popularized single stitch (Shanfield) technique in renal transplantation. MATERIALS AND METHODS: The charts of 721 consecutive transplant recipients from May 1999 to July 2002 were retrospectively reviewed. Ureteral and nonureteral complications were reviewed at 3 to 5-year followup. RESULTS: Of the 721 recipients evaluated 713 were included in the study. There were 360 recipients in the Lich-Gregoir group and 353 in the Shanfield group. A significantly higher rate of ureteral complications occurred in the Shanfield group compared to the Lich-Gregoir group (15.6% vs 3.9%, p <0.0001). The Shanfield group consisted of 20 patients with ureteral leakage, 21 with hematuria, 11 with strictures and 3 who had ureteral stones. The Lich-Gregoir group had 8 patients with ureteral leakage, 5 with hematuria and 1 with a stricture. In comparison, urinary tract infections, delayed graft function and rejection rates were not significantly different between the 2 groups (p = 0.76, 0.12 and 0.19, respectively). CONCLUSIONS: In contrast to other reports, the Shanfield group had significantly more ureteral complications. In particular the Shanfield technique may predispose patients to higher rates of hematuria and stone formation. Based on this large series and published meta-analyses we believe that the stented Lich-Gregoir anastomosis is the superior ureteroneocystostomy technique in renal transplantation.

Generation of human islets through expansion and differentiation of non-islet pancreatic cells discarded (pancreatic discard) after islet isolation.

OBJECTIVES: Islet transplantation is hampered by the shortage of donor tissues. Our objective was to generate islet-like cell clusters (ICCs) from cultures of non-islet pancreatic cells. METHODS: The starting cultured cells came from the non-islet fractions of human pancreases after enzymatic digestion and purification for the purpose of islet isolation. Initially, these cells expanded in monolayer cultures and became confluent on collagen-coated flasks. After trypsination and suspension of these cells in a defined islet differentiation medium, the cells aggregated to form ICCs. RESULTS: The initial cell population consisted of less than 1% of insulin-positive cells, 44% amylase-positive cells, and 41% cytokeratin (CK) 7-positive, or CK19 cells, but PDX-1 cells were absent. Cells from later stages of the monolayer cultures showed signs of dedifferentiation/transdifferentiation. At the time of harvesting, more than 90% of the cells were positive for CK 7/19 and PDX-1, but less than 1% of the cells were insulin-positive. After aggregation, the ICCs appeared redifferentiated, and contained glucose-responsive, insulin-secreting cells with an insulin content measuring 20% of that found in freshly isolated islets isolated from the same pancreas. ICCs transplanted into athymic mice and removed after 4 months did acquire the morphology of mature islets, indicating further maturation of the ICCs in vivo after transplantation. Human C-peptide was detected in recipient animal sera. CONCLUSION: Using the specified culture methods, non-islet pancreas cells can generate cell clusters resembling islets. These ICCs, obtained from fractions of the pancreas that are otherwise discarded, continue to differentiate after transplantation to become mature islets.

Inhibition of p38 pathway suppresses human islet production of pro-inflammatory cytokines and improves islet graft function.

Nonspecific inflammation is associated with primary graft nonfunction (PNF). Inflammatory islet damage is mediated at least partially by pro-inflammatory cytokines, such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) produced by resident islet macrophages. The p38 pathway is known to be involved in cytokine production in the cells of the monocyte-macrophage lineage. Therefore, inhibition of the p38 pathway may prevent pro-inflammatory cytokine production by resident islet macrophages and possibly reduce the incidence of PNF. Our present study has demonstrated that inhibition of the p38 pathway by a chemical p38 inhibitor, SB203580, suppresses IL-1beta and TNF-alpha production in human islets exposed to lipopolysaccharide (LPS) and/or inflammatory cytokines. Although IL-1beta is predominantly produced by resident macrophages, ductal cells and islet vascular endothelial cells were found to be another cellular source of IL-1beta in isolated human islets. SB203580 also inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the treated islets. Furthermore, human islets treated with SB203580 for 1 h prior to transplantation showed significantly improved graft function. These results suggest that inhibition of the p38 pathway may become a new therapeutic strategy to improve graft survival in clinical islet transplantation.

Silymarin protects pancreatic beta-cells against cytokine-mediated toxicity: implication of c-Jun NH2-terminal kinase and janus kinase/signal transducer and activator of transcription pathways.

Silymarin is a polyphenolic flavonoid that has a strong antioxidant activity and exhibits anticarcinogenic, antiinflammatory, and cytoprotective effects. Although its hepatoprotective effect has been well documented, the effect of silymarin on pancreatic beta-cells is largely unknown. In this study, the effect of silymarin on IL-1beta and/or interferon (IFN)-gamma-induced beta-cell damage was investigated using RINm5F cells and human islets. IL-1beta and/or IFN-gamma induced cell death in a time-dependent manner in RINm5F cells. The time-dependent increase in cytokine-induced cell death appeared to correlate with the time-dependent nitric oxide (NO) production. Silymarin dose-dependently inhibited both cytokine-induced NO production and cell death in RINm5F cells. Treatment of human islets with a combination of IL-1beta and IFN-gamma (IL-1beta+IFN-gamma), for 48 h and 5 d, resulted in an increase of NO production and the impairment of glucose-stimulated insulin secretion, respectively. Silymarin prevented IL-1beta+IFN-gamma-induced NO production and beta-cell dysfunction in human islets. These cytoprotective effects of silymarin appeared to be mediated through the suppression of c-Jun NH2-terminal kinase and Janus kinase/signal transducer and activator of transcription pathways. Our data show a direct cytoprotective effect of silymarin in pancreatic beta-cells and suggest that silymarin may be therapeutically beneficial for type 1 diabetes.

Advances in islet cell biology: from stem cell differentiation to clinical transplantation: conference report.

The 3rd Annual Rachmiel Levine Symposium entitled "Advances in Islet Cell Biology-From Stem Cell Differentiation to Clinical Transplantation" was organized by the Department of Diabetes, Endocrinology and Metabolism at the City of Hope National Medical Center, with the support of the Southern California Islet Cell Resources Center, American Diabetes Association-David Shapiro Research Fund, Ross Foundation, the National Center for Research Resources (NCRR), and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health. The symposium was held at the Hilton Anaheim Hotel in Anaheim, CA, in October 2002, and was attended by nearly 400 participants from 23 countries and 30 U.S. states. The symposium consisted of 11 sessions focusing on 3 areas: (1) pancreas and islet cell differentiation and islet generation, (2) beta cell biology and insulin synthesis and/or secretion, and (3) pancreatic islet transplantation in patients with type I diabetes. Thirty-nine world experts lectured on the most current information in each field. Fifty-three abstracts were selected for presentation and discussed at the poster session. The first author of each of the top 10 posters received a Young Investigator Travel Award provided by the National Center for Research Resources and the Southern California Islet Cell Resources Center. The symposium also offered special Meet the Professor sessions, which gave the attendees an opportunity to closely interact with the participating speakers of the day.

Prevention of primary nonfunction of canine islet autografts by treatment with pravastatin.

BACKGROUND: Nonspecific inflammation is the primary cause of early islet graft loss. We have shown in mice that pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, prevents primary nonfunction of islet isografts by reducing inflammatory reactions at the graft site. This study was designed to test the effectiveness of this agent in a large animal model, dogs, by transplanting autologous islets. METHODS: After total pancreatectomy, islets were isolated by using a two-step digestion method, followed by discontinuous gradient centrifugation on EuroFicoll. A known number of freshly isolated islets were immediately transplanted back into the same dog via the portal vein. RESULTS: First, we determined the minimal islet number required to reverse diabetes by transplanting 3,000-10,000 IEQ/kg with no additional treatment. The number was found to be 4,000 IEQ/kg, and islets less than 4,000 IEQ/kg consistently failed. To test the effect of pravastatin, 3,000 IEQ/kg were transplanted into dogs that either received no further treatment or were treated daily with 20 mg/kg of pravastatin from days -2 to 14. Without pravastatin, this number of islets lowered blood glucose only transiently, and all four of these dogs became hyperglycemic within 1 week. In contrast, four of the five dogs treated with pravastatin became normoglycemic (<150 mg/dL) and maintained this level during the observation period of 12 weeks (P<0.05). Postprandial plasma glucose and insulin levels returned to normal, and K values of intravenous glucose tolerance tests were significantly higher in pravastatin-treated dogs than in controls (P<0.04 at week 2 and P<0.01 at week 4). CONCLUSION: Peritransplant pravastatin treatment reduced the number of autologous islets required to reverse diabetes in totally pancreatectomized dogs. These results suggest that pravastatin may also facilitate better islet graft survival and function in clinical transplantation.

Kidney transplantation at UCLA.

The demand for renal transplantation continues to increase. Combined organ transplantation currently accounts for approximately 10% of the kidney transplants at UCLA. As the demand for renal transplantation has increased, living kidney donation has become more common and achieves excellent results. Thirty-five percent of the 1,307 renal transplants at UCLA during the past 5 years were from living donors. The donor morbidity has been reduced with improvements in postoperative analgesia and laparoscopic nephrectomy techniques. Management of the patients waiting for cadaveric renal transplantation is becoming increasingly complex, since this population now exceeds 1,000 patients and the median waiting time is approaching 5 years. Improved immunosuppressive, antibiotic, and antiviral medications have significantly reduced the rate of acute rejection and serious infections. As long-term graft survival improves, the side effect profiles of newer medications are increasingly important. The one- and 3-year graft survival rates during the past 5 years were 98% and 90% for adult recipients of living donor kidneys and were 91% and 82% for recipients of cadaveric grafts, respectively. The results for pediatric transplants were 100% and 97% for living donor kidneys and 97% and 85% for cadaveric grafts at one and 3 years, respectively. We are pleased with our excellent results and the manner in which our program has responded to changes in the organ transplant environment.