Outcomes after simultaneous kidney-pancreas versus pancreas after kidney transplantation in the current era

Simultaneous pancreas and kidney transplant vs. pancreas after kidney transplantation: is one better?

PURPOSE OF REVIEW

For those with insulin dependent diabetes mellitus and renal failure, both simultaneous pancreas and kidney (SPK) and pancreas after kidney (PAK) transplant can free the recipient of renal replacement and insulin therapies and provide survival advantage over ongoing dialysis and diabetes. Yet, pancreas transplants are notably declining in the United States, particularly for PAK.

RECENT FINDINGS

Pancreas transplant continues to provide better glycemic control than all present medical therapies. Outcomes for both SPK and PAK also continue to improve, and overall patient survival for both SPK and PAK are similar, excellent, and superior to all other transplant or medical options. SPK is associated with better pancreas allograft survival, but this gap is narrowing for PAK, and the best kidney allograft survival is achieved with living donor renal transplant (LDRTx) and PAK.

SUMMARY

PAK remains a viable and successful treatment for uremia and insulin dependent diabetes, and, particularly when following a LDRTx, can confer the additional benefits associated with LDRTx and preemptive transplant. To achieve insulin and dialysis independence, either LDRTx followed by PAK (if a living donor is available) or SPK should be offered to candidates with appropriate indications.

New onset diabetic ketoacidosis in a renal transplant recipient

Post-transplant diabetes mellitus (PTDM) is a well-known solid organ transplant complication, which can be related to immunosuppressants, particularly tacrolimus. We report an unusual presentation of PTDM with diabetic ketoacidosis (DKA). This is unique as PTDM typically resembles Type 2 DM, whereas DKA is associated with Type 1 DM and has rarely been reported as a complication of tacrolimus. A 38-year-old African American male on LCP-tacrolimus presented four months post kidney transplant with vomiting, weakness, poor appetite, and polyuria. Labs demonstrated hyperglycemia, ketonuria, and high anion gap metabolic acidosis. He was nonobese and had no personal or family history of Type 2 DM. DKA was suspected to be secondary to tacrolimus-induced pancreatic beta cell damage worsened by supratherapeutic tacrolimus levels. Latent autoimmune diabetes in adults (LADA) was diagnosed when further testing showed insulinopenia, low C-peptide, and anti-glutamic acid decarboxylase (GAD) autoantibodies. He required 120-units of subcutaneous insulin daily. Our literature review revealed only 16 other tacrolimus-induced DKA cases. No cases reported anti-GAD positivity and most showed beta cell toxicity reversibility with tacrolimus tapering or substitution. Our patient was early post-transplant with leukocytopenia, so tacrolimus was not exchanged. This unusual PTDM case may have resulted from both autoimmune and tacrolimus-induced beta cell destruction. Physicians should be aware of new onset LADA post-transplantation and tacrolimus toxicity leading to DKA, even in patients without traditional risk factors. Anti-GAD antibody screening in patients on tacrolimus who develop PTDM may identify patients less likely to recover beta cell function with immunosuppression augmentation which requires careful monitoring.

Pre-Transplant Hypoalbuminemia Is Not Associated With Early Key Outcomes Among Simultaneous Pancreas and Kidney Transplant Recipients

The role of pre-transplant hypoalbuminemia and its impact on post-transplant outcomes in patients undergoing simultaneous pancreas-kidney (SPK) transplantation remains unclear. We analyzed all SPK recipients at our center, who had at least 2 weeks of pancreas and kidney graft survival and had serum albumin measured within 45 days pre-transplant. Recipients were categorized based on pretransplant albumin level as normal (≥4.0 g/dL, N = 222, 42%), mild hypoalbuminemia (≥3.5-<4.0 g/dL, N = 190, 36%), and moderate hypoalbuminemia (<3.5 g/dL, N = 120, 23%). Kidney delayed graft function (DGF), length of stay (LOS) after transplant, re-hospitalization within 30 days after discharge, and need for a return to the operating room (OR) related to transplant surgical complications, acute rejection, and uncensored and death-censored graft failure, within the first years post-transplant were outcomes of interest. A total of 532 SPK recipients were included. Mild or moderate hypoalbuminemia was not associated with DGF, LOS, re-hospitalization, or return to the OR in unadjusted or adjusted analyses. Similarly, mild or moderate hypoalbuminemia was not associated with a risk of graft rejection or graft failure. Among SPK recipients, pre-transplant hypoalbuminemia was not associated with worse outcomes and should not be the determining factor in selecting patients for SPK transplant.

Experience from 100 consecutive pancreas transplants amidst low national transplant activity: a retrospective study at a single center in Korea

Background

Since 1992, over 800 pancreas transplants have been performed in Korea. However, this number is significantly lower compared to the number of kidney or liver transplants.

Methods

Between 2015 and July 2023, Pusan National University Yangsan Hospital conducted 100 pancreas transplants, accounting for about 20% of all transplants performed in Korea during this period. The study comprised 27 simultaneous pancreas and kidney (SPK) transplants, 23 pancreas after kidney (PAK) transplants, and 50 pancreas transplant alone (PTA) cases. Duodenoduodenostomy was the primary surgical technique employed for exocrine drainage, along with various modifications of the venous outflow anastomosis.

Results

The availability of brain-dead donors for kidney transplants was lower compared to isolated pancreas transplants. Patients undergoing SPK transplants faced significantly longer waiting times than those receiving PTA or PAK transplants. The rate of surgical complications was acceptable, with a notably low thrombotic graft failure rate of 1.0%. In the PTA group, acute rejection of the graft pancreas occurred frequently (18.0%), though this was not statistically significant (P=0.328). The pancreas transplantation survival rates were 91.0%, 78.5%, and 75.4% at 1, 5, and 9 years, respectively. The PTA group exhibited a lower graft survival rate than the SPK and PAK groups, with marginal statistical significance (P=0.059).

Conclusions

Graft survival rates have improved over time due to advancements in surgical techniques and immunosuppressant strategies. By sharing our experiences, we aim to enhance the activity and success of pancreas transplantation in Korea.

When pancreata fly: Outcomes and lessons learned from the development of a Pancreas Transplant Import Program

BACKGROUND

To address long waitlist times and increase pancreas transplantation, our center has implemented a protocol for long-distance importation of pancreata.

METHODS

We conducted a retrospective review of pancreas transplantation at our institution from January 1, 2014, the start of our importation program, through September 30, 2021. Outcomes were compared between locally procured grafts and imported grafts, defined as grafts procured greater than 250 nautical miles (NM) from our center.

RESULTS

Eighty-one patients underwent pancreas transplantation during the study time period; 19 (23.5%) received imported grafts. There were no significant differences in recipient demographics or type of transplant received. Mean distance of import was 644.2 ± 234.0 NM. Imported grafts were more likely to be from pediatric donors <18 years old (p = .02) and a significantly higher proportion of imported grafts came from donors weighing <30 kg (26.3 vs. 3.2%, p = .007). Cold ischemic time was longer for imported grafts than for local grafts (13.4 ± 2.3 h vs. 9.8 ± 2.2 h, p < .01). There was no significant difference in deaths or graft losses within 90 days or at 1 year between groups.

CONCLUSION

Centers should consider expanding criteria for acceptance of imported pancreata to increase the number of transplants and combat organ nonutilization.

Higher Fasting Pretransplant C-peptide Levels in Type 2 Diabetics Undergoing Simultaneous Pancreas-kidney Transplantation Are Associated With Posttransplant Pancreatic Graft Dysfunction

BACKGROUND

Among selected patients with type 2 diabetes mellitus (T2DM), simultaneous pancreas and kidney (SPK) transplants can be an effective option. However, data are limited about outcomes in T2DM SPK recipients based on the pretransplant C-peptide levels.

METHODS

In this study, we reviewed all T2DM SPK recipients and categorized them based on the pretransplant fasting C-peptide levels into 3 groups: low (≤2 ng/mL), medium (>2-8 ng/mL), and high (>8 ng/mL). Several measures of graft failures (GFs), graft dysfunction, and composite outcomes were of interest.

RESULTS

There were a total of 76 SPK recipients (low, n = 14; medium, n = 47; high, n = 15). At the last follow-up, the low group did not reach any outcome; in contrast, 11 (23%) in the medium group and 5 (33%) in the high group reached the uncensored composite outcome; 6 (13%) in the medium group and 2 (13%) in the high group had GF; and 8 (17%) in the medium group and 4 (26.7%) in the high group reached the death-censored composite outcomes. In a fully adjusted model, each pretransplant C-peptide unit was not associated with an increased risk of the composite outcome, GF, or death-censored composite outcomes. However, in multivariate analysis with limited adjustment, pretransplant C-peptide was associated with the composite outcome (hazard ratio: 1.18, 95% confidence interval, 1.01-1.38; P = 0.03) and death-censored composite outcome (hazard ratio: 1.20; 95% confidence interval, 1.01-1.42; P = 0.03).

CONCLUSIONS

Although limited by the small sample size, we found excellent outcomes among T2DM SPK recipients overall. However, higher levels of pretransplant C-peptide may be associated with inferior posttransplant outcomes that include graft dysfunction.

An Initial Analysis of the Baseline Levels of Dd-cfDNA After Pancreas Transplantation: A Prospective Study From High-volume Centers in the United States

Pancreas transplantation offers patients with diabetes an opportunity for glucose homeostasis. Current blood tests to surveil for rejection have poor sensitivity and specificity for identifying rejection, and pancreas biopsies are challenging and associated with morbidity and graft loss. Donor-derived cell-free DNA (dd-cfDNA) is shed from transplanted organs and detectable in peripheral blood. Thus, a potential dd-cfDNA blood test assessing rejection would be clinically advantageous.

Methods

One hundred eighty-one dd-cfDNA samples (n) were collected from 77 patients (N) up to 132 mo posttransplant.

Results

The median dd-cfDNA level among all subjects was 0.28% (0.13%, 0.71%). In simultaneous pancreas-kidney (SPK) transplant recipients, the median dd-cfDNA level was 0.29% (0.13%, 0.71%), and it was 0.23% (0.08%, 0.71%) in pancreas transplant alone (PTA) recipients. When isolating for when without infection or rejection, the median dd-cfDNA level was 0.28% (0.13%, 0.64%) for SPK and 0.20% (0.00%, 0.32%) for PTA. Both transplant types approached 1.0% ≤1 mo posttransplant followed by a decrease in median dd-cfDNA. During episodes of rejection or infection, median dd-cfDNA levels were greater among all transplant types.

Conclusions

The mean dd-cfDNA level for all pancreas transplant recipients is <1.0%, consistent with the published kidney transplant rejection threshold (>1.0%), regardless of SPK or PTA. Early posttransplant dd-cfDNA levels are transiently higher than later measurements. Dd-cfDNA elevation also correlates with rejection and infection and thus is a promising biomarker for surveilling pancreas transplant dysfunction.

Effect of donor pancreas extraction time on pancreas transplantation-a Swiss tertiary center experience

We aimed to assess the effect of donor pancreas extraction time (ET) on postoperative complications and graft function after pancreas transplantation (PT). We analyzed all consecutive donor pancreas procurements for the simultaneous pancreas and kidney transplantation (SPK) and the associated PT in a Swiss transplant center over a 20-year period. Pancreas ET was defined as the time from cold flush to static storage of the pancreas on ice. The primary endpoint was the effect of extraction time on surgical complications. Secondary endpoints comprised the effect of ET on graft function (insulin-free survival) and graft pancreatitis. Of 115 procured pancreas grafts the median donor pancreas ET was 65 min (IQR: 48-78 min). In multivariable analysis, ET did not negatively affect major complications (OR 1.41 [95% CI: .59-3.36]; p = .438) and insulin-free survival (HR 1.42 [95% CI: .55-3.63]; p = .459). The median CIT was 522 (441-608) min. CIT was associated with major complications (OR 2.51 [95% CI: 1.11-5.68]; p = .027), but without impact on insulin-free survival (HR 1.94 [95% CI: .84-4.48]; p = .119). Patients with and without graft pancreatitis had no statistically significant differences in ET and CIT (p = .164 and p = .47, respectively). In multivariable analysis, Amylase levels > 270 U/L on postoperative day 1 were significantly associated with major complications (OR 3.61 [95% CI: 1.06-12.32]; p = .040). Our results suggest that although no effect of ET on complications and graft function after PT was found, shorter CIT and less graft pancreatitis can have a positive impact on surgical complications. Results could possibly be influenced by the exceptional quality of the pancreas donors, with short travel distances and preservation times in Switzerland.

The Presence of Donor-specific Antibodies Around the Time of Pancreas Graft Biopsy With Rejection Is Associated With an Increased Risk of Graft Failure

BACKGROUND

Donor-specific antibodies (DSA) against HLA are an important biomarker predicting graft injury, rejection (Rej), and failure in various solid-organ transplant recipients. However, the impact of DSA with or without histopathological evidence of rejection among pancreas transplant recipients (PTRs) is unknown.

METHODS

In this study, we included all PTRs at our center between 2005 and 2020, with pancreas allograft biopsy before March 31, 2021, and with DSA checked within 15 d of the biopsy. PTRs were divided into 4 groups based on the biopsy findings on the index biopsy and DSA status as Rej-/DSA-, Rej+/DSA-, Rej-/DSA+, and Rej+/DSA+.

RESULTS

Two hundred two PTRs had a pancreas allograft biopsy during the study period. Thirty-nine were in Rej-/DSA-, 84 Rej+/DSA-, 24 Rej-/DSA+, and 55 Rej+/DSA+. The mean interval from transplant to index biopsy was not statistically different between the 4 groups. The most common type of rejection was T cell-mediated rejection; however, antibody-mediated rejection was more prevalent in the Rej+/DSA+ group. At 5 y postbiopsy, the rate of death-censored graft failure (DCGF) for Rej-/DSA- was 18%, 24% in Rej+/DSA-; 17% in Rej-/DSA+ and 36% in Rej+/DSA+ (P = 0.14). In univariate analysis, mixed rejection (hazard ratio [HR], 3.0; 95% confidence intervals [CI], 1.22-7.39; P = 0.02) along with solitary pancreas transplantation and Rej+/DSA+ were associated with DCGF. In multivariate analysis, compared with Rej-/DSA-, Rej+/DSA+ was significantly associated with DCGF (HR, 2.32; 95% CI, 1.03-5.20; P = 0.04); however, Rej+/DSA- was not (HR, 1.06; 95% CI, 0.32-3.56; P = 0.92).

CONCLUSIONS

PTRs with pancreas allograft rejection and concomitant DSA have an increased risk of DCGF.

Association of human leukocyte antigen mismatches between donor-recipient and donor-donor in pancreas after kidney transplant recipients

The effects of HLA mismatching on pancreas outcomes among pancreas after kidney (PAK) recipients are undefined. Outcomes might potentially differ depending on whether there is a mismatch between pancreas donor and recipient (PD-R) or pancreas donor and kidney donor(PD-KD). All primary PAK at our centre were included in this study. Patients were divided into two groups based on the degree of HLA mismatching: low (L-MM) as 0-4 and high (H-MM) as 5-6. We analysed all (N = 73) PAK for PD-R mismatch and the subset of PAK for PD-KD mismatch (N = 71). Comparing PD-R L-MM (n = 39) and H-MM (n = 34) PAKs, we observed no difference in the rate of pancreas graft failure. There was also no difference in the rate of rejection (L-MM 33% vs. H-MM 41%) or the severity of rejection. However, we observed a significantly (P < 0.01) shorter time to acute pancreas rejection in the H-MM group (6.8 ± 8.7 mo) versus the L-MM cohort (29.0 ± 36.2 mo) (P < 0.001). Similar to the PD-R mismatched cohort, we did not observe a detrimental effect of HLA mismatching on graft outcomes in the PD-KD cohort; time to rejection was again shorter in the H-MM subset. In this study, we found no impact of HLA mismatch on either pancreas graft survival or rejection rates, though rejection occurred earlier in high mismatched PAK transplants.

Inferior survival outcomes of pancreas transplant alone in uremic patients

Theoretically, pancreas transplant alone in uremic (PTAU) patients could also be one of the options for those waiting for both pancreas and kidney grafts, but it has never been reported. There were 160 cases of pancreas transplant in this study, including 16% PTAU. The 5-year patient survival was 66.2% after PTAU, 94.5% after SPK, 95.8% after PAK, and 95.4% after PTA. Rejection of pancreas graft was significantly lower in PTAU group (3.8%), followed by 16.7% in pancreas after kidney transplant (PAK), 29.8% in simultaneous pancreas and kidney transplant (SPK) and 37.0% in pancreas transplant alone (PTA). Fasting blood sugar and serum HbA1c levels after PTAU were not significantly different from those by other subgroups. The 5-year death-censored pancreas graft survival was 100% after PTAU and PAK, and 97.0% after SPK and 77.9% after PTA. However, the 5-year death-uncensored pancreas graft survival was 67.0% after PTAU, 100% after PAK, 91.3% after SPK, and 74.0% after PTA. The superior graft survival in the PTAU group was achieved only if deaths with a functioning graft were censored. In conclusion, given the inferior patient survival outcome, PTAU is still not recommended unless SPK and PAK is not available. Although PTAU could be a treatment option for patients with diabetes complicated by end-stage renal disease (ESRD) in terms of surgical risks, endocrine function, and immunological and graft survival outcomes, modification of the organ allocation policies to prioritize SPK transplant in eligible patients should be the prime goal.

Transplant Options for Patients With Diabetes and Advanced Kidney Disease: A Review

Optimal glycemic control in kidney transplant recipients with diabetes is associated with improved morbidity and better patient and allograft survival. Transplant options for patients with diabetes requiring insulin therapy and chronic kidney disease who are suitable candidates for kidney transplantation should include consideration of β-cell replacement therapy: pancreas or islet transplantation. International variation related to national regulatory policies exists in offering one or both options to suitable candidates and is further affected by pancreas/islet allocation policies and transplant waiting list dynamics. The selection of appropriate candidates depends on patient age, coexistent morbidities, the timing of referral to the transplant center (predialysis versus on dialysis) and availability of living kidney donors. Therefore, early referral (estimated glomerular filtration rate < 30 mL/min/1.73 m²) is of the utmost importance to ensure adequate time for informed decision making and thorough pretransplant evaluation. Obesity, cardiovascular disease, peripheral vascular disease, smoking, and frailty are some of the conditions that need to be addressed before acceptance on the transplant list, and ideally before dialysis becoming imminent. This review offers insights into selection of pancreas/islet transplant candidates by transplant centers and an update on posttransplant outcomes, which may have practice implications for referring nephrologists.

Risk factors for intra-abdominal fungal infection after simultaneous pancreas-kidney transplantation: A single-center retrospective experience

BACKGROUND

Data on the risk factors and outcome of intra-abdominal fungal infections (IAFI) following simultaneous pancreas-kidney transplantation (PKT) are scarce.

MATERIALS/METHODS

A retrospective monocentric study was conducted on all patients who underwent simultaneous PKT from January 2007 to December 2016. Deep sites positive cultures for fungi during the first post-transplantation year were collected. Clinical, radiological, and microbiological data of proven and probable invasive fungal infections were analysed.

RESULTS

Among sixteen PKT patients, 15 were included. Seven patients (47%) developed an invasive fungal infection, exclusively IAFI (six proven, one probable). The proven IAFI included four peritonitis, one pancreatic necrosis with infected hematoma, and one patient with positive preservation fluid only (PF). Candida albicans (n = 4) was the most prevalent species (associated with Galactomyces candidus in one case), C glabrata, C dubliniensis, and C krusei were found in one case each. Three patients had either a positive direct examination and/or culture for renal or pancreatic PF and the culture of PF was positive for the same species that caused IAFI. IAFIs were significantly associated with pancreatic graft arterial thrombosis (5/7 vs 0/8, P = .007) and fungal contamination of PF (3/7 vs 0/8, P = .008). Among patients with IAFI, all required an early surgical revision post-transplantation [1-18 days] and six had early or delayed pancreatic graft removal. One patient died in the first post-transplant year.

CONCLUSION

IAFI is a common complication in PKT, associated with pancreatic graft thrombosis or fungal contamination of the graft PF, and can sometimes lead to pancreatic detransplantation.

Outcomes of simultaneous pancreas and kidney transplants based on preemptive transplant compared to those who were on dialysis before transplant - a retrospective study

Among kidney transplant recipients, the duration of pretransplant dialysis is significantly associated with worse post-transplant outcomes. However, data on the outcomes of preemptive simultaneous pancreas and kidney (SPK) are limited. We analyzed primary SPK recipients transplanted between January 2000 and December 2017. Patients were divided into two groups based on pretransplant dialysis history of preemptive versus non-preemptive. Patient and survival of grafts were outcomes of interest. Of the 644 recipients, 174 (27%) were preemptive and 470 (73%) were not. Most of the baseline characteristics were similar between the groups. In the univariable analysis, the non-preemptive transplant was associated with 54% increased risk for kidney death-censored graft failure (DCGF; HR: 1.54; 95% CI: 1.01-2.35; P = 0.05). There was a 29% increased risk after adjustment for confounding factors (HR: 1.29; 95% CI: 0.83-2.02; P = 0.26), although this association was not statistically significant. Similarly, there was a 16% increased risk of pancreas DCGF in univariable analysis and 1% after adjustment, which was also not statistically significant. When outcomes were based on the duration of pretransplant dialysis, the duration was not associated with either patient survival or survival of either graft in K-M analysis. In SPK recipients, with pretransplant dialysis history, there was a tendency toward inferior graft survival, mainly for the kidney more than the pancreas.