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Biomedical subjects

D E Sutherland

Publications and source records attributed to D E Sutherland.

At least 361 records · Page 20Linked to original sources

The impact of HLA matching on graft survival and on sensitization after a failed transplant--evidence that failure of poorly matched renal transplants does not result in increased sensitization.

There are costs (both financial and ethical) to distributing kidneys by HLA-match (time, transportation, repeat crossmatch; possibly bypassing a more deserving recipient). Arguments favoring matching include better short- and long-term survival, and decreased panel-reactive antibody (PRA) if a well-matched vs. poorly matched transplant fails. We studied these phenomena in a single institution. Since 1970, 1329 patients received cadaver (CAD) transplants; for those with defined antigens (n = 1316) there was no difference in 10-year graft survival in those with a less than or equal to 1 AB match vs. those with greater than 1 AB match or those with less than or equal to 1 AB mismatch (mm) vs. greater than 1 AB mm. Similarly there was no difference in those with less than or equal to 2 BDR mm vs. greater than 2 BDR mm. In fact, those with less than ABDR mm had worse 10-year graft survival (55%) than those with greater than or equal to 3 ABDR mm (61%) (P = .001). For patients with function greater than 6 months there was no difference in long-term outcome based on HLA match or mm. These findings were similar for patients both with and without CsA immunosuppression, and for primary and retransplants. A total of 382 patients transplanted since 1980 have lost their grafts (146 died with function). All had received pretransplant transfusions. Of 236 alive after graft loss, 64 had no postgraft failure PRAs (22 out of state, 23 chose to remain on dialysis, 19 died less than 3 months after graft loss); 172 had PRAs after failure; 106 (62%) have been retransplanted. Mean peak PRA in those retransplanted was 23 +/- 31 (range 0-100) vs. 46 +/- 39 (range 0-100) in those not retransplanted (P less than .05). Patients were stratified by PRA prior to first transplant (0%, 1-20%, greater than 20%). For recipients with 0% PRA, failure of a CAD transplant (n = 58) was no more likely to result in an increase of PRA than failure of a living-related donor (LRD) transplant (n = 49) (NS). For those with an increase, mean increase was 45% +/- 34 after LRD transplant and 41% +/- 28 after CAD transplant (NS). The proportion developing PRA greater than or equal to 60% was not different after a failed LRD (7/49) or CAD (11/58) transplant (NS). Other subgroups had similar results. AZA or CsA immunosuppression did not affect development of increased PRA after a failed graft.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibody Formation↗

A new in vitro approach to determine acquired tolerance in long-term kidney allograft recipients.

Previous studies indicate some kidney allograft recipients treated with total lymphoid irradiation, cyclosporine, or conventional immunosuppressive therapy demonstrate specific proliferative unresponsiveness in mixed lymphocyte culture (MLC) to donor cells at various times posttransplant. To investigate possible donor-specific hyporeactivity, we have studied 3 patients treated with TLI whose grafts have survived longer than 10 years; 2 patients given the same immunosuppressive protocol but without TLI whose grafts have survived longer than 10 years; and 27 CsA-treated living-related donor and cadaver-allograft recipients 1 year posttransplant. We confirmed previous observations of hyporeactivity of some patients' cells to stimulation by donor cells. In addition, we identified hyporeactivity to stimulation by homozygous typing cells (HTCs) defining the HLA-Dw specificities of the donor cells for all 3 of the 3 TLI patients, 1 of the 2 non-TLI patients, and 9 of the 27 patients 1 year posttransplant. The LRD recipients with donor-specific hyporeactivity as defined by the HTC analysis demonstrated fewer rejection episodes (25% vs. 57%) and lower mean creatinine levels (1.18 vs 1.78 mg/dL) than patients without donor-specific hyporeactivity. These studies demonstrate the feasibility of monitoring the immune status of allograft recipients posttransplant by means of HTC analysis, eliminating the need for pretransplant specimens. This approach provides a possible means to assess which patients may have acquired donor-specific hyporeactivity to their kidney allograft and thus may require less immunosuppression.

Clone Cells↗

Canine pancreatic islet transplantation: a comparison of two isolation techniques.

A new method (type B) for isolation of canine islets was developed, utilizing intraductal collagenase perfusion, stationary digestion, filtration and tissue separation by means of a dextran density gradient. The results of this technique were compared with those of a previously established method (type A). Islets were autotransplanted either via the splenic or the portal vein. Lasting normoglycemia was obtained in 5/8 intrasplenic type B transplants (63%), 6/8 intrahepatic type B transplants (75%), 5/6 intrasplenic type A transplants (83%) and 0/3 intrahepatic type A transplants. No difference was found in metabolic parameters 2 weeks after successful transplantation following type A or B islet isolation. Islet yield was higher with type A and purification better with type B isolation. Both techniques are relatively simple and inexpensive. Because of its higher purification rate and the success of intrahepatic islet transplantation method B has replaced method A as the routine procedure in our laboratory.

Animals↗

Glucagon, catecholamine and pancreatic polypeptide secretion in type I diabetic recipients of pancreas allografts.

Successful pancreas transplantation in type I diabetic patients restores normal fasting glucose levels and biphasic insulin responses to glucose. However, virtually no data from pancreas recipients are available relative to other islet hormonal responses or hormonal counterregulation of hypoglycemia. Consequently, glucose, glucagon, catecholamine, and pancreatic polypeptide responses to insulin-induced hypoglycemia and to stimulation with arginine and secretin were examined in 38 diabetic pancreas recipients, 54 type I diabetic nonrecipients, and 26 nondiabetic normal control subjects. Glucose recovery after insulin-induced hypoglycemia in pancreas recipients was significantly improved. Basal glucagon levels were significantly higher in recipients compared with nonrecipients and normal subjects. Glucagon responses to insulin-induced hypoglycemia were significantly greater in the pancreas recipients compared with nonrecipients and similar to that observed in control subjects. Glucagon responses to intravenous arginine were significantly greater in pancreas recipients than that observed in both the nonrecipients and normal subjects. No differences were observed in epinephrine responses during insulin-induced hypoglycemia. No differences in pancreatic polypeptide responses to hypoglycemia were observed when comparing the recipient and nonrecipient groups, both of which were less than that observed in the control subjects. Our data demonstrate significant improvement in glucose recovery after hypoglycemia which was associated with improved glucagon secretion in type I diabetic recipients of pancreas transplantation.

Arginine↗

Detection of pancreatic fluid and urine leakage after pancreas transplantation: value of CT and cystography.

Leakage from the urinary bladder or duodenal stump after pancreas transplantation with urinary bladder drainage of the graft is difficult to diagnose clinically. We retrospectively reviewed our experience with fluoroscopic cystography and CT to determine their relative merit in the diagnosis of pancreatic fluid and urine leakage as documented by surgical exploration in pancreas transplant recipients. Thirteen leaks were diagnosed by fluoroscopic cystography or by CT in 11 patients after pancreas transplantation with urinary bladder drainage of pancreatic fluid. Conventional retrograde fluoroscopic cystography showed 11 leaks; CT with retrograde bladder opacification showed three leaks. Of the five CT studies that did not show a leak and that also were done within 7 days of a cystogram with abnormal findings, failure to use retrograde bladder opacification accounted for the majority (three cases) of missed diagnoses. Focal or free peritoneal abdominal fluid was seen in all CT examinations, with extravasation of contrast material seen into both walled-off collections and free ascites. Our experience suggests that retrograde bladder and duodenal stump opacification should be a routine part of the CT evaluation performed to detect leakage from the urinary bladder or duodenal stump after pancreas transplantation.

Anastomosis, Surgical↗

Systemic venous drainage of pancreas allografts as independent cause of hyperinsulinemia in type I diabetic recipients.

To evaluate the metabolic consequences of pancreas transplantation with systemic venous drainage on beta-cell function, we examined insulin and C-peptide responses to glucose and arginine in type I (insulin-dependent) diabetic pancreas recipients (n = 30), nondiabetic kidney recipients (n = 8), and nondiabetic control subjects (n = 28). Basal insulin levels were 66 +/- 5 pM in control subjects, 204 +/- 18 pM in pancreas recipients (P less than 0.0001 vs. control), and 77 +/- 17 pM in kidney recipients. Acute insulin responses to glucose were 416 +/- 44 pM in control subjects, 763 +/- 91 pM in pancreas recipients (P less than 0.01 vs. control), and 589 +/- 113 pM in kidney recipients (NS vs. control). Basal and stimulated insulin levels in two pancreas recipients with portal venous drainage were normal. Integrated acute C-peptide responses were not statistically different (25.3 +/- 4.3 nM/min in pancreas recipients, 34.2 +/- 5.5 nM/min in kidney recipients, and 23.7 +/- 2.1 nM/min in control subjects). Similar insulin and C-peptide results were obtained with arginine stimulation, and both basal and glucose-stimulated insulin-C-peptide ratios in pancreas recipients were significantly greater than in control subjects. We conclude that recipients of pancreas allografts with systemic venous drainage have elevated basal and stimulated insulin levels and that these alterations are primarily due to alterations of first-pass hepatic insulin clearance, although insulin resistance secondary to immunosuppressive therapy (including prednisone) probably plays a contributing role. To avoid hyperinsulinemia and its possible long-term adverse consequences, transplantation of pancreas allografts into sites with portal rather than systemic venous drainage should be considered.

Adult↗

Influence of pancreas transplantation on cardiorespiratory reflexes, nerve conduction, and mortality in diabetes mellitus.

Cardiorespiratory reflexes (CRR) were studied by measuring heart-rate variation during 6 breaths/min respiration and a Valsalva maneuver in 232 insulin-dependent diabetic subjects. Abnormalities were found in 175 patients. During a 7-yr follow-up, 41 (23.4%) patients with abnormal and 2 (3.5%) with normal CRR tests died. The mortality rates of diabetic patients with abnormal autonomic function tests were 17% at 2.5 yr, 33% at 5 yr, and 40% at 7 yr, significantly higher (P less than 0.002) than in patients with normal tests (rates of 4.6, 4.6, and 13.8% at the respective intervals). Nerve conduction studies (NCS) were indicative of somatic neuropathy in 148 of 205 patients. Mortality rates were higher in patients with abnormal NCS than in those with normal results (P less than 0.025). Among patients with abnormal autonomic function, patients with a functioning pancreas transplantation (PTx) had better survival rates than patients with a failed PTx (P less than 0.005) and, on long-term follow-up, better rates than patients without PTx. Similar results were found comparing the same group of patients who had abnormal NCS.

Adult↗

Long-term follow-up of renal transplantation for Wegener's disease.

Eight patients with end-stage renal failure due to Wegener's granulomatosis underwent renal transplantation at the University of Minnesota. Seven patients were alive with a functioning graft 40 to 128 months posttransplant (mean follow-up: 91 months). One patient died 126 months posttransplant with a well-functioning graft. Posttransplant immunosuppression controlled primary disease in all but 1 patient, who presented with perisinusitis. Recurrent disease was not noted in any of the transplanted organs. We conclude that transplantation is an excellent treatment for renal failure secondary to Wegener's disease.

Adolescent↗

Lessons learned and future hopes: three thousand renal transplants at the University of Minnesota.

1. The experience of 3,183 transplants between June 7, 1963 and September 30, 1990 at the University of Minnesota was reviewed. 2. Patients were divided into 4 historical periods-each era was associated with improved outcome. 3. As results have improved, the proportion of patients less than 5 years old and the proportion greater than 50 years old have increased. Type I diabetes has become the most common cause of renal failure in patients transplanted here. 4. The most important variable leading to improved outcome was donor source. Both HLA-identical and HLA-nonidentical LRD transplants have better outcome than CAD transplants (p less than 0.0001). 5. Multivariate analyses were done to determine risk factors for survival: a) in the first year, and b) in subsequent years. In the first year, age greater than 50, diabetes, and retransplantation had an adverse affect whereas LRDs and CsA immunosuppression were beneficial. Similar factors affected survival after the first year. HLA mismatch had no impact. 6. When death with graft function was excluded, diabetes and age greater than 50 were no longer risk factors, suggesting that the excess graft loss in these groups was due to patient death. 7. Chronic rejection and death with function remain the predominant causes of graft loss. 8. As protocols have evolved, results have improved, and previously "high-risk" patients are being successfully transplanted. Future efforts should be directed at decreasing graft loss from rejection and death with function.

Adult↗

Pancreas transplantation: report on United States results from United Network for Organ Sharing Registry with comparison to non-United States results from the International Registry.

From December 17, 1966 to December 31, 1990, 3,069 pancreas transplants worldwide (1,806 United States and 1,263 non-United States) were reported to the International Pancreas Transplant Registry, including 606 in 1990. The 2,871 pancreas transplants in the Registry data base as of October 31, 1990 were analyzed. Results worldwide improved in each of 5 successive eras. The recipient and pancreas graft functional survival rates at 1 year for all 1988 to 1990 cases (n = 1,415) were 91% and 68%, respectively. The effect of multiple variables on outcome was determined by analyzing the 2,037 cases in the International Registry data base since 1985. Worldwide, BD (n = 1,566) was used more frequently than DI (n = 327) or ED (n = 174) and was associated with a significantly higher (p less than 0.001) graft functional survival rate, at 1 year 65% versus 56% and 53%, respectively. Worldwide, SPK transplants (n = 1,644) were performed much more frequently than either PAK (n = 223), or PTA (n = 212). The pancreas graft functional survival rate was significantly higher (p less than 0.001) in the SPK than in the other 2 categories, at 1 year being 68% versus 45% and 37%, respectively. The kidney graft survival rate for all SPK cases at 1 year was 80%. Worldwide, a significant effect of HLA-DR matching was seen only in analysis of PTA, graft survival at 1 year being 54% in PTA recipients matched for 2 DR antigens (n = 13), 44% for 1 DR antigen (n = 63) and 29% for 0 DR antigens (n = 97) (p = 0,015 for 2 vs 0 DR). Worldwide, more than half of the pancreas grafts were preserved in UW solution (n = 1,111), and an increasing preservation length was not associated with a significant decrease in functional survival rates, at 1 year being 67%, 73%, 71%, and 60% for those stored less than 12 (n = 563), 12-24 (n = 416), 24-30 (n = 30), and greater than 30 (n = 5) hours. A separate analysis was performed on pancreas transplants in the United States reported to the UNOS Registry from its inception on October 1, 1987 to October 21, 1990 (n = 1,021). Almost all pancreas transplants in the United States during this period were by the BD technique (92%). The overall patient and pancreas graft survival rates were 92% and 72% at 1 year.(ABSTRACT TRUNCATED AT 400 WORDS)

Follow-Up Studies↗