Prospective, randomized trial of the effect of antibody induction in simultaneous pancreas and kidney transplantation: three-year results

BACKGROUND

Historically, antibody induction has been used because of the higher immunologic risk of graft loss or rejection observed in simultaneous pancreas and kidney (SPK) transplantation compared with kidney transplantation alone. This trial was designed to assess the effect of antibody induction in SPK transplant recipients receiving tacrolimus, mycophenolate mofetil, and corticosteroids. Induction agents included T-cell-depleting and interleukin-2 receptor antibodies.

METHODS

A total of 174 SPK transplant recipients were enrolled in a prospective, open-label, multi-center study. They were randomized to induction (n=87) or non-induction (n=87) groups and followed for 3 years.

RESULTS

At 3 years, actual patient (94.3% and 89.7%) and pancreas (75.9% and 75.9%) survivals were similar between the induction and non-induction groups, respectively. Actual kidney survival was similar at 1 and 2 years, but at 3 years, it was significantly better in the induction group compared with the non-induction group (92% vs. 81.6%; P =0.04). At 3 years, median serum creatinine and hemoglobin A1C were similar between the induction and non-induction groups (1.35 mg/dL and 1.20 mg/dL, 5.4% and 5.5%, respectively). Three-year cumulative incidence of biopsy-confirmed, treated acute kidney rejection in the induction and non-induction groups was 19.5% and 27.5% (P =0.14), respectively, with odds 4.6 times greater in African Americans regardless of treatment (P =0.004). Significantly higher rates of cytomegalovirus (CMV) viremia and CMV syndrome occurred in those receiving T-cell-depleting antibody induction (36.1%) when compared with those receiving anti-interleukin-2 receptor antibodies (2%) and non-induction (8.1%) (P <0.0001).

CONCLUSIONS

Tacrolimus, mycophenolate mofetil, and corticosteroids resulted in excellent safety and efficacy in SPK transplant recipients. Actual 3-year kidney survival was significantly better in the induction group; however, CMV viremia and CMV syndrome rates were significantly higher in the T-cell-depleting antibody group. African Americans demonstrated a significantly greater risk of acute rejection despite antibody induction. Decisions regarding the use of induction therapy must weigh the risk of kidney graft loss or rejection against the risk of infection.

Transplant options for patients undergoing total pancreatectomy for chronic pancreatitis

BACKGROUND

Total pancreatectomy to treat chronic pancreatitis is associated with severe diabetic control problems in 15% to 75% of patients, causing up to 50% of deaths late postoperatively. We report our experience with islet autotransplants at the time of, or with pancreas allotransplants after, total pancreatectomy.

STUDY DESIGN

Between February 1, 1977, and June 30, 2003, we performed 112 islet autotransplants at the time of total pancreatectomy; we also performed 20 pancreas allotransplants in 13 patients who had already undergone total pancreatectomy months to years earlier.

RESULTS

Islet autotransplants at the time of total pancreatectomy in patients who had not had previous operations on the body and tail of the pancreas were associated with a high islet yield (>2,500 islet equivalents/kg body weight), and >70% of the recipients achieved complete insulin independence. In contrast, a previous distal pancreatectomy or a Puestow drainage procedure was associated with a low islet yield in 75% of them and with complete insulin independence in <20%. A pancreas allotransplant after total pancreatectomy was not associated with any transplant-related mortality at 1 and 3 years posttransplant. The pancreas graft survival rate at 1 year posttransplant was 77% with tacrolimus-based immunosuppression (versus 67% with cyclosporine). Enteric (over bladder) drainage was preferred to manage exocrine graft secretions, to cure pancreatectomy-induced endocrine and exocrine insufficiency.

CONCLUSIONS

Our series shows that pancreas allotransplants can be performed without transplant-related mortality and, when tacrolimus-based immunosuppression is used, with 1-year pancreas graft survival rates >75%. In contrast to a simultaneous islet autotransplant, a pancreas allotransplant has the disadvantage of requiring lifelong immunosuppression, but the advantage of not only curing endocrine but also exocrine insufficiency. Both transplant options, if successful, improve the recipient's quality of life.

Risk factors and impact of delayed graft function after pancreas transplants

Delayed graft function (DGF) occurs after many pancreas transplants (PTx), but is poorly characterized. We studied its incidence, course, and impact in a series of 531 pancreas transplants. Between January 1997 and September 2002, we performed 531 technically successful primary PTx. Of these 531 recipients, 176 (33%) had DGF, defined by their need for exogenous insulin at the time of hospital discharge. The incidence of DGF was roughly equivalent in the three transplant categories: SPK (36%), PAK (32%), and PTA (31%) (p = NS). By 3 months posttransplant, only 19 (3.5%) of all recipients remained on insulin. Only three recipients (0.56%) did not achieve insulin independence. The mean donor age of recipients with DGF was 35.1 years vs. 28.8 years without DGF (p = 0.003). By multivariate analysis, the most significant risk factor for DGF was donor age > 45 years (RR = 4.3, p = 0.0001). For SPK recipients with DGF, graft survival was 87% at 1 year and 82% at 3 years posttransplant; without DGF, 94% at 1 year and 87% at 3 years (p = 0.07). For PAK and PTA recipients, no difference was noted. Acute rejection rates were somewhat higher in recipients with DGF, but this did not reach statistical significance.

The impact of donor obesity on outcomes after cadaver pancreas transplants

We examined the impact of donor obesity on surgical complications and graft function after pancreas transplants. From January 1994 through December 2001, we performed 711 cadaver pancreas transplants. We analyzed outcomes for three groups based on donor body mass index (BMI): <25 kg/m2 (n=434), 25-30 (n=196), and >30 (n=81). Donor characteristics were similar between the three groups except for donor cause of death. Cerebrovascular deaths were more common in the BMI >30 group (p=0.002), while trauma deaths were more common in the BMI <25 group (p=0.02). In the BMI >30 group, surgical complications, most notably surgical infections and thrombosis, were significantly more common; in addition, technical failure rates were higher and short-term graft survival was inferior. The incidence of technical failure was 9.7% in the BMI <25 group, 16.3% in the BMI 25-30 group, and 21.0% in the BMI >30 group (p=0.04). However, when we looked at only technically successful transplants, we found minimal differences in the three groups with regard to graft survival at 1 and 3 years posttransplant. Donor obesity increased the incidence of surgical complications in our pancreas recipients, but did not affect initial graft function posttransplant. Technically successful transplants using obese donors results in good graft function at 1 and 3 years posttransplant.

Transplantation of cultured islets from two-layer preserved pancreases in type 1 diabetes with anti-CD3 antibody

We sought to determine whether or not optimizing pancreas preservation, islet processing, and induction immunosuppression would facilitate sustained diabetes reversal after single-donor islet transplants. Islets were isolated from two-layer preserved pancreata, purified, cultured for 2 days; and transplanted into six C-peptide-negative, nonuremic, type 1 diabetic patients with hypoglycemia unawareness. Induction immunosuppression, which began 2 days pretransplant, included the Fc receptor nonbinding humanized anti-CD3 monoclonal antibody hOKT3gamma1 (Ala-Ala) and sirolimus. Immunosuppression was maintained with sirolimus and reduced-dose tacrolimus. Of our six recipients, four achieved and maintained insulin independence with normal HbA1c levels and freedom from hypoglycemia; one had partial islet graft function; and one lost islet graft function 2 weeks post-transplant. The four insulin-independent patients showed prolonged CD4+ T-cell lymphocytopenia; inverted CD4:CD8 ratios; and increases in the percentage of CD4+CD25+ T cells. These cells suppressed the in-vitro proliferative response to donor cells and, to a lesser extent, to third-party cells. Severe adverse events were limited to a transient rash in one recipient and to temporary neutropenia in three. Our preliminary results thus suggest that a combination of maximized viable islet yield, pretransplant islet culture, and preemptive immunosuppression can result in successful single-donor islet transplants.

Comparison of tolerated and rejected islet grafts: a gene expression study

Recently we showed that donor-specific tolerance to MHC-matched islet allografts in diabetic NOD mice could be induced by simultaneous islet and bone marrow transplantation. Mononuclear cell infiltration surrounding the islets was also found in tolerated grafts. In this study, we compared gene expression in the tolerated and rejected islet grafts by using Affymetrix Murine U74A oligonucleotide arrays. To confirm the results of microarray analysis, we performed real-time PCR and RNase protection assay on selected genes. Of over 12,000 genes studied, 57 genes were expressed at consistently higher levels in tolerated islet grafts, and 524 genes in rejected islet grafts. Genes from a variety of functional clusters were found to be different between rejected and tolerated grafts. In the rejected islet grafts, a number of T-cell surface markers and of cytotoxicity-related genes were highly expressed. Also in the rejected grafts, a number of cytokines and chemokines and their receptors were highly expressed. The differential expression of selected genes found by microarray analysis was also confirmed by real-time PCR and RNase protection assay. Our results indicated that gene microarray analysis can help us to detect gene expression differences representative of the biologic mechanisms of tolerance and rejection.

Chronic rejection: the next major challenge for pancreas transplant recipients

OBJECTIVE

With newer immunosuppressive agents, acute rejection and graft loss resulting from acute rejection have become less common for pancreas transplant recipients. As long-term graft survival rates have improved, an increasing number of grafts are being lost to chronic rejection (CR). We studied the incidence of CR and identified risk factors.

METHODS

We retrospectively analyzed all cadaver pancreas transplants performed at the University of Minnesota between June 19, 1994, and December 31, 2002. We determined the causes of graft loss, the incidence of graft loss to CR and, using multivariate techniques, the major risk factors for CR.

RESULTS

A total of 914 cadaver pancreas transplants were performed in the following three categories: simultaneous pancreas-kidney (SPK) (n=321), pancreas after kidney (PAK) (n=389), and pancreas transplant alone (PTA) (n=204). The mean recipient age was 41.3 years and the mean donor age was 30.1 years. Of the 914 pancreas grafts, 643 (70.3%) continue to function (mean length of follow-up, 39 months). The most common cause of graft loss was technical failure, accounting for 118 (12.9%) of the failed grafts. The second most common cause was CR, accounting for 80 (8.8%) of the failed grafts. The incidence of graft loss to CR was highest for PTA (n=23 [11.3%]) and PAK (n=45 [11.6%]) recipients and lowest for SPK recipients (n=12 [3.7%]) (P=0.002). By multivariate analysis, the most significant risk factors for graft loss to CR were a previous episode of acute rejection (relative risk [RR]=4.41, P<0.0001), an isolated (vs. simultaneous) transplant (PAK or PTA [vs. SPK], RR=3.02, P=0.002), cytomegalovirus infection posttransplant (RR=2.41, P=0.001), a retransplant (versus primary transplant) (RR=2.27, P=0.004), and one or two (vs. zero) antigen mismatches at the B loci (RR=1.68, P=0.04).

CONCLUSIONS

As short-term pancreas transplant results improve and as isolated (PAK or PTA) pancreas transplants gain in popularity, CR will become increasingly common as a cause of pancreas graft loss.

Transplantation for diabetes mellitus

Justifiably expanding

Blockade of the CD40/CD154 pathway enhances T-cell-depleted allogeneic bone marrow engraftment under nonmyeloablative and irradiation-free conditioning therapy

BACKGROUND

T-cell-depleted bone marrow transplantation (TDBMT) can prevent graft-versus-host disease (GvHD). However, depleting T cells from allogeneic bone marrow often results in failure of bone marrow engraftment under irradiation conditioning. It is not know whether donor T cells are essential for bone marrow engraftment and whether blocking the CD40/CD154 pathway promotes allogeneic TDBM engraftment under nonmyeloablative and irradiation-free fludarabine phosphate and cyclophosphamide conditioning therapy.

METHODS

Using fully major histocompatibility complex (MHC)-matched mouse models, we investigated whether donor T cells are essential for bone marrow engraftment under fludarabine phosphate and cyclophosphamide conditioning therapy. We also determined whether the barrier of allogeneic TDBM could be overcome by blocking the CD40/CD154 pathway. Donor chimerism was detected by flow cytometric analysis. Donor-specific tolerance through establishing mixed chimerism was tested in vivo by skin transplantation and in vitro by mixed leukocyte reaction and enzyme-linked immunospot (ELISPOT) assay.

RESULTS

Compared with unmodified bone marrow, TDBM resulted in poor engraftment when fully MHC-mismatched donors were used. However, anti-CD154 monoclonal antibody (mAb) treatment significantly enhanced donor TDBM engraftment. TDBM engraftment was also seen in CD154 knockout mice. A stable and high level of multilinage donor chimerism was achieved. Recovery of host CD3 T cells was suppressed, and recovery of donor CD3 T cells was promoted, after TDBMT and anti-CD154 mAb treatment. Donor chimerism was established by TDBMT induced donor-specific tolerance in vivo and in vitro.

CONCLUSION

Donor T cells facilitate bone marrow engraftment under nonmyeloablative and irradiation-free conditioning therapy, and the blocking the CD40/CD154 pathway can replace donor T cells to promote TDBM engraftment.

Prospective, randomized, multi-center trial of antibody induction therapy in simultaneous pancreas-kidney transplantation

A randomized, multicenter, prospective study was conducted at 18 pancreas transplant centers in the United States to determine the role of induction therapy in simultaneous pancreas-kidney (SPK) transplantation. One hundred and 74 recipients were enrolled: 87 recipients each in the induction and noninduction treatment arms. Maintenance immunosuppression consisted of tacrolimus, mycophenolate mofetil, and corticosteroids. There were no statistically significant differences between treatment groups for patient, kidney, and pancreas graft survival at 1-year. The 1-year cumulative incidence of any treated biopsy-confirmed or presumptive rejection episodes (kidney or pancreas) in the induction and noninduction treatment arms was 24.6% and 31.2% (p = 0.28), respectively. The 1-year cumulative incidence of biopsy-confirmed, treated, acute kidney allograft rejection in the induction and noninduction treatment arms was 13.1% and 23.0% (p = 0.08), respectively. Biopsy-confirmed kidney allograft rejection occurred later post-transplant and appeared to be less severe among recipients that received induction therapy. The highest rate of Cytomegalovirus (CMV) viremia/syndrome was observed in the subgroup of recipients who received T-cell depleting antibody induction and received organs from CMV serologically positive donors. Decisions regarding the routine use of induction therapy in SPK transplantation must take into consideration its differential effects on risk of rejection and infection.

Glucagon, catecholamine, and symptom responses to hypoglycemia in living donors of pancreas segments

Donors undergoing hemi-pancreatectomy to provide a pancreas segment for transplantation into a relative with type 1 diabetes acquire diminished insulin and glucagon responses to intravenous agonists. Some donors develop diabetes and require treatment for hyperglycemia. They become at risk for hypoglycemia when treatment includes sulfonylureas and insulin. However, no studies assessing the impact of hemi-pancreatectomy in humans on islet alpha-cell responses to hypoglycemia have been reported. Consequently, we performed stepped hypoglycemic clamps in 7 donors of varying glycemic control and compared their responses to 16 control subjects. Donors and control subjects reached similar nadirs of glycemia (45 +/- 3 and 41 +/- 1 mg/dl, respectively) during the clamp. The donors had significantly higher mean basal glucagon levels than control subjects (203 +/- 27 vs. 135 +/- 15 pg/ml; P < 0.03) but did not have significant differences in glucagon responses during the clamp. The donors also had significantly higher mean peak epinephrine responses during the clamp (1,231 +/- 134 vs. 730 +/- 68 pg/ml; P < 0.002), but there were no statistically significant differences in norepinephrine or symptom responses. The glucose thresholds at which hormonal and symptom responses began were not different. We conclude that although glucagon response to arginine and insulin response to glucose and arginine are diminished after hemi-pancreatectomy, no deficiency in glucagon responses were detected during hypoglycemia.

Improved islet yield and function with ductal injection of University of Wisconsin solution before pancreas preservation

BACKGROUND

Ensuring sufficient islet yield from preserved pancreases is a critical step in clinical islet transplantation. The aim of this study was to investigate whether pancreatic ductal injection, performed at procurement, using a small volume of preservation solution before cold storage (ductal preservation method) would improve islet yield and function from rat pancreases preserved for 6 and 24 hr.

MATERIALS AND METHODS

Islets were isolated from Lewis rats. Pancreases were classified into five groups: fresh (group 1); preserved for 6 hr in University of Wisconsin solution without and with ductal preservation (groups 2 and 3); and preserved for 24 hr in University of Wisconsin solution without and with ductal preservation (groups 4 and 5). We assessed islet yield, function, and viability of pancreatic ductal cells.

RESULTS

Islet yields per pancreas in groups 1 to 5 were 2010+/-774, 674+/-450, 1418+/-528, 527+/-263, and 1655+/-618 (islet equivalent) (+/-SD), respectively. Stimulation indices in groups 1 to 5 were 11.97+/-3.17, 6.48+/-4.04, 12.44+/-5.65, 2.56+/-2.03, and 5.55+/-2.71. Functional success rates in groups 1 to 5 were 100%, 0%, 100%, 0%, and 66.7%. Percentages of nonviable pancreatic duct cells in groups 1 to 5 were 3.8+/-2.7%, 59.7+/-4.4%, 19.5+/-7.3%, 64.7+/-4.5%, and 17.2+/-2.6%. In all experiments, the differences were significant between the groups without versus the groups with ductal preservation (P<0.05, group 2 vs. group 3 and group 4 vs. group 5).

CONCLUSIONS

Ductal preservation improved islet yield and function after 6 and 24 hr of preservation. Well-preserved pancreatic ducts maintained good distribution of collagenase solution.

Pancreas transplantation in crossmatch-positive recipients

BACKGROUND

Prolonged cold preservation time can unfavorably affect outcome in pancreas transplantation. To reduce this ischemic time, cadaver pancreas grafts, in selected cases, are sometimes transplanted before crossmatch results are known. We report our experience with pancreas transplants in recipients with either current or historically positive T- or B-cell crossmatches.

METHODS

Crossmatch-positive pancreas transplants were identified using a computerized database. T-cell crossmatches were performed using an antihuman-globulin-augmented complement-dependent cytotoxicity (CDC) test; B-cell crossmatches were performed using an extended incubation CDC test. All patients received anti-T-cell induction therapy and either cyclosporine (1987-1993) or tacrolimus-based (1994-2001) immunosuppression. More recent recipients (2000-2001) also received intravenous gamma globulin and postoperative plasmapheresis.

RESULTS

Between October 1, 1987 and March 31, 2001, of a total of 1076 pancreas transplants performed, 59 (5.48%) were crossmatch-positive. Of these, 8 had a current T-cell-positive crossmatch and 15 had a current B-cell-positive crossmatch. One recipient was both current B- and T-positive, and the rest were past B- and/or T-cell positive. One-year pancreas graft survival for current T- and B-cell crossmatch-positive transplants was 63% and 67%, respectively. T- or B-cell crossmatch-negative transplants had a 1-yr survival of 70%. In the T-cell crossmatch-positive group, four grafts are still functioning (follow-up range, 2-12 yr), one patient died with a functioning graft at 4 months, and four grafts failed (one each from pancreatitis, infection, primary nonfunction, and vascular thrombosis). No grafts were lost to rejection. In the B-cell crossmatch-positive group, six grafts are still functioning (follow-up range, 2-11 yr) and nine have failed (four from chronic rejection, three from vascular thromboses, and two from pancreatitis). Crossmatch-positive cases were significantly more likely to be retransplants (70.8%) than crossmatch-negative cases (14.8%, p < 0.0001). In a multivariate analysis, crossmatch positivity did not affect pancreas graft outcome, whereas retransplants had a significant impact on outcome (relative risk 1.84, p < 0.0001).

CONCLUSIONS

(: i) Pancreas transplants performed in the setting of a positive current crossmatch may have long-term function. (ii) With current immunosuppressive protocols, graft loss from hyperacute and acute rejection may be prevented in current crossmatch-positive pancreas transplants. Chronic rejection was only seen in B-cell crossmatch-positive cases. (iii) High rates of technical graft loss in crossmatch-positive cases may reflect a high frequency of retransplants in this group.

Predicting long-term kidney graft survival: can new trials be performed?

BACKGROUND

As short-term transplant results improve, it has become difficult to use patient or graft survival or acute rejection as clinical trial endpoints, except in large, multicenter studies. Despite better outcomes, graft failure continues over time.

METHODS

We studied 6- and 12-month creatinine (Cr) level and change in creatinine (deltaCr) level (3-12 months, 6-12 months) as predictors of graft survival for 1,389 primary kidney transplants (minimum graft survival 1 year). Determining the prognostic value of Cr level (6 or 12 months), the subgroups were as follows: less than 1, 1 to 1.4, 1.5 to 1.9, 2.0 to 2.4, 2.5 to 2.9, and greater than or equal to 3 mg/dL. For deltaCr level, the subgroups were as follows: less than 0, 0, 0.01 to 0.2, and greater than 0.2. Subgroup actuarial graft survival was determined. Cox regression analyses were performed with forward, stepwise selection.

RESULTS

After 12-month Cr level entered the model, no other variable was significant. Repeating this with continuous variables, 12-month Cr level was again the best predictor. Five-year graft survival for 12-month Cr level less than 1 (n=38) was 95%; for 1.0 to 1.4 (n=454), 87%; for 1.5 to 1.9 (n=463), 86%; for 2.0 to 2.4 (n=166), 78%; for 2.5 to 2.9 (n=54), 60%; for greater than or equal to 3 (n=45), 41%. A major breakpoint for outcome is 1-year Cr level=2.0. A power analysis was performed for the combined endpoint of graft loss and 1-year Cr level greater than 2, reached by 30% of patients. To avoid missing a reduction to 20% (actual decrease 33%) (alpha=0.05; power=0.8), 313 patients would be required per group. For a reduction to 15% (actual decrease 50%), 133 patients would be required.

CONCLUSIONS

Twelve-month Cr level is an accurate surrogate for long-term outcome. The use of a combined endpoint (graft loss and 12-month Cr level) allows trials to be performed without exorbitant numbers.

A substantial level of donor hematopoietic chimerism is required to protect donor-specific islet grafts in diabetic NOD mice

BACKGROUND

Mixed chimerism can induce tolerance to alloantigens and restore self-tolerance to autoantigens, thereby permitting islet transplantation. However, the minimal level of donor chimerism that is required to prevent islet allograft rejection and recurrence of autoimmune diabetes has not been established.

METHODS

We investigated whether allogeneic Balb/c donor chimerism can be induced in C57BL/6 mice, in prediabetic NOD mice, and in diabetic NOD mice after transplantation of a modest dose of bone marrow by using purine nucleoside analogue, fludarabine phosphate and cyclophosphamide conditioning therapy, followed by short-term anti-CD40 ligand monoclonal antibody and rapamycin posttransplant treatment. We also investigated whether the induced donor chimerism is sufficient to prevent the onset of diabetes in prediabetic NOD mice and protect donor islet grafts in diabetic NOD mice.

RESULTS

Allogeneic donor chimerism could be induced under the authors' approach that is nonmyeloablative and radiation-free. Diabetes onset was prevented in chimeric prediabetic NOD mice. The induction of mixed chimerism protected donor-specific islet grafts in diabetic NOD mice. At 60 days after islet transplantation, all donor Balb/c islet grafts survived in diabetic NOD mice whose level of donor-derived lymphocytes was higher than 30% at the time of islet transplantation (n=8). In contrast, Balb/c islet grafts were rejected in five of seven diabetic NOD mice whose level was lower than 30%.

CONCLUSIONS

Our data demonstrate that a donor lymphocyte chimerism (>30%) at the time of islet transplantation is required to protect donor-specific islet grafts, and indicate that a strictly non-irradiation-based protocol can be used to achieve this goal.

Pancreas transplant outcomes for United States (US) and non-US cases as reported to the United Network for Organ Sharing (UNOS) and the International Pancreas Transplant Registry (IPTR) as of May 2003

As of December 31, 2003, more than 21,000 pancreas transplants had been reported to the IPTR, >15,000 in the US and >5,000 outside the US. An era analysis of US cases from 1987 to May 15, 2003 showed a progressive improvement in outcome (p<0.04), with pancreas transplant graft survival rates (GSRs) going from 76% at one year for 1987-92 to 85% for 2001-2003 SPK cases, from 57%-79% for PAK cases, and from 55%-76% for PTA cases. The improvements were due both to decreases in technical failure rates (from 15%-10% in SPK, 21%-13% in PAK, and 24%-8% in PTA) and immunological failure rates (going from 6%-1% for SPK, from 23%-4% for PAK, and from 28%-7% for PTA cases). The proportion of recipients >45 years old increased from 11% in all 3 recipient categories in 1987-92 to 32-36% for 2001-2003 cases, and the improved outcomes encompassed the older patients as well. Contemporary pancreas transplant outcomes were calculated separately for January 1, 1999- May 15, 2003 US and non-US cases. The results of the US analysis are summarized first. US patient survival rates at one year were >95% in each recipient category, with one-year primary pancreas GSRs of 85% for SPK (n=3,775), 79% for PAK (n=951), and 78% for PTA (n=403) (p<0.0001). The immunological graft failure rates for 1996-2002 technically successful SPK, PAK and PTA cases were 2% (n=3,437), 5% (n=854), and 7% (n=356) at one year (p=0.0001). There was a progressive increase in the use of ED (as opposed to BD) for duct management. For 1999-2003 US primary pancreas transplants, ED was used in 78% of SPK, 60% of PAK and 49% for PTA cases. Of the ED transplants, venous drainage via the portal system was used for 23% of SPK, 27% of PAK and 44% of PTA cases. Pancreas GSRs were nearly identical for 1999-2003 ED (n=2,898) and BD (n=798) SPK transplants (85% for both at one year), nor was there a significant difference (p>0.17) in pancreas GSRs for systemic (n=2,218) versus portal (n=680) venous drained ED SPK transplants (84% vs 87% at one year). Kidney GSRs were not significantly different for ED versus BD SPK cases, 93% and 92% at one year (p=0.24). Pancreas GSRs for PAK transplants were 82% at one year for BD (n=360; all systemic venous drainage) versus 77% for ED with systemic (n=398) versus 74% for ED with portal (n=150) venous drainage (p=0.03 overall, and 0.02 for ED portal vs ED systemic). For PTA cases, one-year GSRs were 81% with BD (n=196; all systemic venous drainage) versus 69% for ED with systemic (n=99) versus 80% for ED with portal (n=90) venous drainage (p > or = 0.08 overall, and 0.11 for ED portal vs ED systemic). BD transplants were associated with a 12-14% conversion rate to ED by 2 years after transplantation in the 3 recipient categories. The age of US pancreas transplant recipients made little difference for outcome in the SPK category, with one-year pancreas GSRs ranging from 80-85% for patients grouped by age in decades from 10-19 to 60-69 years. In the PAK category, one-year GSRs tended to increase with age, going from 71% for those 20-29 to 89% for those 60-69 years old. Likewise, in the PTA category one-year GSRs were higher in older than younger donors, age, being only 50% in 10-19 year-old and 87% in 40-49 year-old recipients. Pancreas GSRs were identical (85% at one year) for 1999-2003 US SPK recipients reported to have Type 1 (n=3,479) or Type 2 (n=231) diabetes (6% classified as Type 2). TAC+MMF was the dominant maintenance immunosuppressant for 1999-2003 US cases (approximately two-thirds) and with this regime one-year GSRs were >81% in all 3 recipient categories. The results were very similar (> or = 79% one-year GSR) in patients (approximately 10%) treated with sirolimus under various protocols. HLA-B locus matching had a significant effect on pancreas transplant outcome in the PTA category. For 1999-2003 cases the one-year rejection loss rate was 15% in recipients mismatched for 2 B-locus antigens (n=28) versus 3% and 4% for those mismatched for one (n=114) or zero (n=82) antigens. The proportion of 1999-2003 US pancreas grafts that were retransplants was <2% in the SPK and only 9% in the PTA categories, but 23% in the PAK category. The majority of the latter were done after isolated failure of a pancreas graft in SPK recipients. Pancreas retransplant GSRs at one year were 69% in the SPK (n=60), 77% in the PAK (n=288) and 73% in the PTA (n=39) categories, significantly lower than for primary grafts only in the SPK category (p=0.001). In regard to non-US pancreas transplants, even in 1999-2003 the overwhelming majority were in the SPK category (n=1,833), with one-year patient, kidney and pancreas survival rates of 98%, 94% and 89%, slightly but significantly higher than those for US cases done during the same period. Non-US PAK (n=55) GSR at one year was 88%, similar to that for US cases done during this period, but the non-US PTA (n=80) GSR at one year was lower at 66%. In summary, with modern immunosuppression (TAC + MMF for maintenance) 1999-2003 US pancreas transplant graft survival rates were > or = 80% at one year in all categories of recipients (SPK, PAK, PTA), as was the case for non-US SPK and PAK transplants.

Combined liver and pancreas procurement from a controlled non-heart-beating donor with aberrant hepatic arterial anatomy

BACKGROUND

The critical shortage of transplantable organs has resulted in the use of extended donors, including non-heart-beating donors (NHBDs). Combined procurement of both a whole pancreas and a liver from a single cadaver is always anatomically feasible. However, when aberrant vasculature is present, the potential for vascular injury increases. Because the rapid flush technique is used in NHBD procurement, the inability to palpate arterial pulsation may also increase the chance of vascular damage.

METHODS

We report a case of a successful combined procurement of hepatic, pancreatic, and renal grafts from a controlled NHBD with right replaced and left accessory hepatic arteries.

RESULT

The liver and the pancreas were successfully transplanted to two different recipients in two different institutions without any complications. All grafts are functioning well at 14 months of follow-up.

CONCLUSION

Safe procurement of both the liver and pancreas is possible from certain controlled NHBDs, even with aberrant anatomy.